pre contract

Industrial Training Maga Engineering (pte)Ltd

01. INTRODUCTION TO THE TRAINING ORGANIZATION

1.1 Establishment and the function of the organization

Mäga Engineering (Pte) Ltd is a one of the leading construction firm (contractor) in

Srilanka. I.e. the recent ‘Awards Winner of construction Excellence’. In addition to

contractor work, now they design some structural, shoring and other required design. Future it

will become as a design and built firm. During last decades it has shown a huge improvement

in their competitive market as a construction firm. In the early stage mäga was involved in the

manpower supply only. But now they are the proud structural main contractor of massive civil

engineering projects in Srilanka. And more importantly now they are getting works more

frequently. Not only that, they are the proud contractor of some massive building, road works,

drainage systems, concrete supply (Batching plant), mechanical systems and also leasing

company.

Department of Civil Engineering 1

Projects

Batching plant Control workshop Project Leasing structure

Galle Rajagriya Gampola Katunayake


Main functions of organization:

1. Work as a main contractor

2. Work as a sub contractor

3. Operate sub contractor for some special work

4. Operate the concrete batching plants for their own purposes and supply the ready mix

concrete to other construction.

1.2 Some current projects of mäga engineering (Pte) Ltd

Kandy shopping complex 900 million Rupees

Kandy car park 470 million Rupees

Road project (southern province) >1000 million Rupees

Vocational Training Centre-Narahenpittea 180 million Rupees

Mixed Development Project –Bambalapitia 550 million Rupees

BIA Cargo Building project 550 million Rupees

1.3 Some recent past projects of mäga engineering (Pvt) Ltd

As a main contractor

Lanka Apollo Hospital 700 million Rupees

Millennium Information Technology Malambe 450 million Rupees

Eden Hotel Beruwala 250 million Rupees

Light house Hotel Galle 200 million Rupees

Blue water Hotel Wadduwa 250 million Rupees

Sin Hotel Kalutara 168 million Rupees

As a sub contractor

QEQ project Port-Authority 300 million Rupees

AES Kelaanitissa 300 million Rupees

Gampola Bridge 85 million Rupees

Mahiyangana road and bridge 350 million Rupees

Taj Exotica hotel Wadduwa 168 million Rupees

All these projects are massive projects; mainly massive projects are done by mäga.

This give a clear idea about mäga engineering (pte) ltd is one of the leading construction firms

in Srilanka,



1.4 Organizational structure of the Mäga engineering (Pte) Ltd

Even though Maga engineering (Pte) Ltd has done massive work, they have a large number of

staff with them and very talented and the efficient, experience. Brief chart is shown below.

Department of Civil Engineering

Chairman / managing director

Finance director

Director administration

Dir, engineering (planning & dev)

Assistant accountant

General Manager Administration

Estimating dept, planning

Coordinating engineering

Director operation

3

Finance department

Driver orators General administer Stores

Dir.eng design&con


Site organization chart


GING GANGA

INTAKE

AREATOR

FLASH MIXTURE

Industrial Training Maga Engineering (pte)Ltd GREATER GALLE WATER SUPPLY PROJECT

Nature of the Work

This is also one of major project of Maga. Normally the Galle area felt drinking water

problems. Previously here no any water supply system took over. So that national water

supply and drainage board under take this project to solve this problems. This project has

many components such as

1. Construction of intake structure and low lift pump house at Wackwella

2. Construction of water treatment plant

Areator Flash mixture Clarifier focculator Sand filter Sldge drying beds Recoverypit

3. Construction of Ground Reservoirs.

Clear water reservoir - 3000 m3

Hapugalla reservoir - 12000m3

Kowulhena reservoir - 7000m3

Halloluwagada reservoir - 7000 m3

Mahagoda reservoir - 3000 m3

4. Laying of transmission main

Water treatment plant to Hapugala reservoir … 1.1km

Water treatment plant to Mahagoda reservoir – 4.3.km

Hapugala reservoir to Kowulhena reservoir – 9.4 km

Kowulhena reservoir to Halloluawagoda reservoir – 10.1 km

5. Laying of main distribution system

The main Reservoir is in Hapugala area. that include pump house system also. From

there, the water is pumped to other reservoirs. Other reservoirs are constructing in Mahagoda,

Kowlhele, and Kallolugoda. Intake plant has been constructing in Wackwella by Maha. The

treatment plant of water supply project has been constructing in Hapugala by the Access

Company. Maga constructing distribution line also. Two sections is Distribution line 1 and

distribution line 2.

Department of Civil Engineering 5CLARIFIER FOCCULATORSAND FILTERCLEARWATER RESERVOIR3000M3

HAPUGALA RESERVOIR12000M3

KOWLHENA RESERVOIR7000M3HALLOLUWAGODA RESERVOIR

7000M3 MAGAGODA RESERVOIR 3000M3

THROUGH SALINITY BARRIER SLDGE DRYING

BEDS


Ø800mm

Ø600mm

Ø600mm

Ø150mm

Ø450mm (2 line) Ø450mm

Ø450mm (2 line) Ø450mm

Ø600mm Ø350mm Back wash

Ø400mm Ø800mm

Ø600mm

Ø400mm

Ø500mm

FLOW CHART OF GREATER WATER SUPPLY PROJECT


RECOVERYPIT


PROJECT DETAILS

Project :-Greater Galle Water Supply Project

kowlhena Ground reservoir

Client :-National Water Supply Board

Main contractor :-KOLON-SAMSUNG CONSORTIUM

Kolon Eng. & const.co.Ltd

SAMSUNG Coporation

Consultant :-CEYWATER CONSULTANTS (PVT) LTD

Sub Contractor :- Maga Engineering (Pvt) Ltd.&

Access construction &

CML Edwards Construction

Source of water :- Gin-ganga

Design Demand :- 32000 Cubic meters per day (7.1 million populations)

Type of contract :-Design,Build & Turnkey Contract

Contract No. :-P&D/GREATER GALLE/W/DBT/2000/01

Total cost :-Rs.96, 163,190.96

Project start date :- 01 July 2002

Project finished date :-09 may 2005

Kowlhena Ground Reservoir

I engaged in Kowlhena reservoir for two months training periods. That time the main

structural work had been completed. The following sub works are going on:-

In & Out Hume pipe laying.

Painting & tiling work for Chlorination house and Guard

room.

Reservoir roof slab dolomites & metal laying.

Entrance Road work.

Drainage line around the reservoir.

Security fencing work.

Curb stone line with disk drain.

Fixing of entrance steel gate.



EXCAVATION

Before a foundation can be laid it is necessary to excavate a trench of the required

depth and width. Initially survey was done to establish the level in the whole area to quantify

the excavation. Level was measured for each and every square of grid on middle and edges of

square. Bulk-excavation need to be done up to bottom of the screed of basement slab.

Excavation quantify was calculated from the existing levels and excavation bottom level.

Excavation was done 1m below the ground level. Excavation was difficult and time

consuming using man power

For small area excavation, man power was used. Excavation areas were kept under moist

conditions to minimize dust pollution in the site.

Machinery & Equipment used for bulk excavation

Excavator

JCB site master

Tractor

Disposal of earth

All excavated bad soils were disposed off site by using tractor. Sometime excavated

soil was reused for back filling work. Disposal area was kept wet while spreading of earth.

Blondish stone removing

First tried to remove the blondish stone by manual but, could not remove. After that

drilling hammer and air compressor were used to remove but, whole stone could not remove.

Then large bucket excavator and breaker were used to remove that stone. This excavator was

brought by low bed transport.

Backfilling

Over excavated areas were back filled with suitable materials selected from the

excavation. Those approval fill material was deposited in layers of max.300mm or less, as can

be thoroughly compacted with rollers, vibrator. No layers were deposited until the previous

layer has been compacted to the satisfaction of the engineer, and also no filling of excavation

were commenced until these had been approved and measured by the engineer. Compaction

was done until the soil gets its required properties (dry density, etc).proctor compaction test

was done


Industrial Training Maga Engineering (pte)Ltd Machinery & Equipment used for backfilling & compacting

Tractors

JCB site master

Excavator

Roller

Vibrating rammer

Field Density Test by Sand Cone Method

After the compaction of each layer the density achieved in the

field should be determined. In the site sand cone method can be done to determine the

density of the compacted fill material.

In the sand cone method small holes are made at several places in the compacted

layer. The weight of the soil removed can be measured. The volume of the hole can be

obtained by filling the hole with sand (density of the sand is known). Then the density of

the soil can be calculated.

The standard proctor compaction density value can be compared with the field

density. Field compaction density is usually specified to be above 98% of the standard

proctor compaction test in the laboratory for sub base and ABC materials layers. If not

further compaction is necessary.

Calculation for Degree of Compaction

Volume of the hole = Weight of sand in the hole

Density of the sand used

Wet density of the soil = Wet soil in the excavation hole

Volume of the hole

Dry Density of the excavated soil = Wet Density * 100

(Moisture content of the soil + 100)


Industrial Training Maga Engineering (pte)Ltd Degree of Compaction = Dry Density of the Excavated soil *100

Lab Maximum Dry Density

Procedure

A hole about 6” wide and 6” deep was dug into the compacted soil.

The soil was removed from the hole was weighted.

The jar was weighted before the filling the hole.

A cone and jar apparatus containing special fine-grained uniform sand was placed

over the hole, and hole was filled with sand.

The jar was weighted again after filling the hole.

Sample from the soil was taken and weighted

Then completely dried and weighted again (the amount of water lost, divided by the

dry weight gives the moisture in the soil)

Calculation

Weight of can +sand 1 =W1

Weight of can +sand 2 =W2 (after filling)

Weight of sand =W1 –W2

Bulk density of sand = D (Known)

Volume of funnel = V1 (known)

Volume of hole = (W1 –W2)/D –V1 =V2

Weight of can +soil from hole = M1

Weight of can = M2

Weight of wet soil = (M1 – M2)

Bulk density = (M1 – M2)/V2 =D2

Weight of can =w1

Weight of can +wet soil =w2

Weight of can+ dry soil =w3

Weight of wet soil =w2-w1

Weight of dry soil =w3-w1

Weight of water =w2-w3

Moisture content = (w2-w3)/( w3-w1)Department of Civil Engineering 10

Industrial Training Maga Engineering (pte)Ltd Dry density =D2/ [1+ {(w2-w3)/ (w3-w1)}]

Dry density

Max

Density

Moisture content

Optimum

Moisture content

From this degree of compaction can be calculated

Degree of Compaction = Dry Density of the Excavated soil *100

Lab Maximum Dry Density

Screed (Lean) concrete

Grade 15 (1:3:6)/40 mm aggregate size concrete is normally used for screed concrete.

But, grade 20(1:2:4) /20 mm aggregate size concrete was used .first screed concrete bottom

level was measured after that top level was marked in steel rod by using level instrument

(sometime theodolite ) . Before the concreting, water cured. Then there was concreted. Screed

concrete thickness was 75 mm.

Waterproofing


Industrial Training Maga Engineering (pte)Ltd Water proofing member was fixed above the screed concrete top. It is fixed to prevent

water movement towards the structural inside. There is different kind of water proofing

system.In my site polythene was used for water proofing membrane.

FOUNDATION

Foundation is the lowest part of a structure .which a building rests and its purpose

is to safely the load of a building to a suitable sub soil. Generally, foundations are placed

below the ground level to increase the stability of a structure or a building.

The objectives of providing foundation

To distribute and transmit the total load acting on the structure to a larger are of

underlying support.

To prevent excessive settlement and differential settlement of the structure.

To provide stability to the structures against many disturbing forces e.g. wind, rain,

earth quake etc.

Principal types of reinforced concrete foundations

1. Strip foundation

2. Isolated or pad foundation

3. Raft foundation

4. Combined foundation

5. Piled foundation

Strip foundation

Reinforced concrete strip foundations are used to support and transmit the loads from

heavy walls. Tensile reinforcement is therefore required in the lowest face of the strip with

distribution bars in the second layer running longitudinally.

Normally, weak concrete (grade 15 (1:3:6)/40 mm agg) is used for blinding concrete

but, in my site grade 20 concrete (1:2:4/20 mm agg) was used for blinding concrete.

Normally, grade 20 concrete (1:2:4/20 mm agg) is used for reinforcement concrete. But, in

my site grade 35 (1:1:1) concrete was used because water pressure is most. 600 mm height

concrete layer was placed. 16 mm Φ rebar is used in 2 layers with 100 mm space in each

other. The rebar should not to touch the water bar.

Isolated or pad foundation


Industrial Training Maga Engineering (pte)Ltd This type of foundation is used to support and transmit the loads from piers and

columns. The most economic plan shape is a square but if the columns are close to the site

boundary it may be necessary to use a rectangular plan shape of equivalent area. In my site

every pad foundation was square.

Normally, weak concrete (grade 15 (1:3:6)/40 mm agg) is used for blinding concrete






Combined foundation

Having a square base is not always possible. If the structure has a wall on the

boundary of the site the columns would be located eccentrically, if conventional isolated

bases were employed. One method of overcoming this problem is to place the perimeter

columns on a reinforced concrete continuous column foundation in the form of a strip. The

strip is designed as a beam with the columns acting as point loads which will result in a

negative bending moment occurring between the columns requiring top tensile reinforcement

in strip.

Normally, weak concrete (grade 15 (1:3:6)/40 mm agg) is used for blinding concrete.






Raft foundation

The principle of any raft foundation is to spread the load over the entire area of the site.

This method is particularly useful where the column loads are heavy and thus requiring large

bases or where the bearing capacity is low , again resulting in the need for large bases, there

are three type of raft foundation such as

Solid slab Raft foundation

Beam and slab Raft foundation

Cellular Raft foundation


Industrial Training Maga Engineering (pte)Ltd Solid slab Raft foundations are constructed of uniform thickness over the whole raft

area, which can be sometimes wasteful since the design must be based on the situation

existing where the heaviest load occurs.

Normally, weak concrete (grade 15 (1:3:6)/40 mm agg) is used for blinding concrete.






REINFORCED CONCRETE

Concrete is strong in compression, but weak in tension

Steel is very strong in tension.

Concrete is much cheaper than steel

Therefore, concrete is used to resist compressive loads, but steel has to be

incorporated into concrete wherever tensile loads are likely to occur. Because steel is

so expensive, the designer has to keep the quantity of steel to a minimize.

Steel and concrete can be used in combination because:

Upon hardening, concrete bonds firmly to the steel.

Concrete and steel expand and contract at the same rate under temperature changes.

Concrete has a high resistance to damage by fire and thus protects the steel, which is

easily damaged by fire.

Types of stresses

The following are the principal type of stress, which develop in structural members:

(1)Compression

Compressive stresses tend to cause concrete to crush.

(2)Tension

Tensile stresses tend to cause concrete to stretch and crack

(3)Shear

Shear stresses tend to cause sliding between adjacent sections of concrete

BOND AND ANCHORAGEDepartment of Civil Engineering 14

Industrial Training Maga Engineering (pte)Ltd A good bond between the concrete and steel must be, achieved.

Bond can be increased with:

Clean bar

Deformed bars

High strength concrete

Thorough compaction of the concrete

Reinforcing steel has to be extended beyond the region of tensile stress to develop satisfactory

bond strength. If there is not enough room to extend a bar, a bend or hook is used to develop

bond with the concrete.

REINFORCING STEEL

Types of Reinforcing Steel

Hot-rolled plain round bar (Structural grade).

Hot-rolled deformed bar (Structural grade)

Cold-worked deformed bar (CW bars).

Hard-drawn wire,

Reinforcing fabric (made from hard-drawn wire),

In our site hot – rolled plain round bar (mild steel) and hot –rolled deformed bar (Tor

steel) were used.It is important to be aware of the different types of reinforcing steel, how to

identify them and where to use them. In schedules, “R” for round is mild steel in the form of

plain smooth bars.

“T” or “Y” denotes steel, which has a ribbed appearance and may be twisted. This is

used to be known as high tensile steel, which is called as tor steel or yield steel.

Tor steel

Tor steel is produced in the form of cold hoisted deformed bars for concrete

reinforcement and available almost all standard diameters, ranging from 6mm to 50mm.but in

our site we used (10-32) mm bars. For all reinforcement work tor steel was used and its

strength is 460N/mm2.

Mild steel


Industrial Training Maga Engineering (pte)Ltd Mild steel is soft carbon steel and it contains (0.2-0.5) percentage of carbon. This can

be easily cut and bend. In addition, its strength is 250N/mm2. Therefore, it is mostly used for

column stirrups and beam stirrups. In our site the 6 and 10 mm diameters bars were used.

Naming reinforcement bars

Reinforcement on details drawings is described by a coding system to simplify

preparation and reading of the details.

For example: - 25T20-65-125B1

25 - No of bars

T - Type of steel (T-tor steel & R-Mild steel)

20 -Bar diameter in mm

65 -Bar mark

125 -Spacing

B1 - Bottom (position)

Abbreviations used

B1 - Bottom reinforcement

B2 - Distribution bars in bottom net

T1 - Top reinforcement

T2 - Distribution bars in top net

C/C - Center to center

ALT -Alternatively

Weight of tor steel

1m tor steel weight is calculated approximately below the equation.

Weight = diameter² / 162.162

Diameter is in mm

Weight is in kg/m


Bar type Weight (kg/m)

T10

T12

T16

T20

T25

T32

T40

0.616

0.888

1.579

2.466

3.854

6.313

9.86416


Lapping of two bars

Normal length of the full bar is 12 mm. if the reinforcement bar is exceeding 12 mm

then provided lapping. It is carried out according to the standard specification. The designed

lap length in our site is 50 *Ø, where Ø is bar diameter.

Example:-

(1.) Lapping

Lapping length = 50 * Ø

= 50* 20

= 1000 mm

(2.) Lapping

Lapping length =50 * Ø

= 50* 20 (small bar diameter)

= 1000 mm

Crank of bar


T20

T20

T32

T20


Y

X

Y: X =1:10

Before accepting deliveries of reinforcing steel, always check the following:

Type of steel is correct.

bar sizes are correct

Any damage to the bars

Any sign of bar corrosion.

Do not accept any steel, which is not satisfactory.

Cleaning reinforcement

A wire brush was used to remove all loose rust and scale. Mud, form oil, paint etc, can

be removed by a solvent which is not oil based, e.g. petrel. If the steel is rusted, remember the

following point

Loose, flakey or soft rust must be removed, as it will prevent the concrete bonding to

the steel.

Heavy corrosion reduces the effective size of reinforcement, and an engineer’s advice

should be sought before using it.

Very light rust causes no problems and it can even improve the bond between steel and

concrete.

Stacking Reinforcement

The following points should be remembered when stacking reinforcing steel on a job site

Stack it off the ground, to protect it from mud.

Stack it conveniently according to size and length.

Ensure that each bundle is correctly labeled with waterproof tags.

Bending reinforcement


Industrial Training Maga Engineering (pte)Ltd Probably the simplest device for beading bars up to 12mm in diameter is a 3m

length of pipe whose internal diameter is slightly greater than the diameter of the bar. This

method can be used when the bends are simple and the quantity is not great.

For general work up to 20 mm diameter bar, simple hand, operated machines are

available. These machines consist of a flat sleet plate on which is fixed a bending pin around

which the bar is bent.

When bar is bended, the following point should be noted

Bar must be bent accurately to the dimensions shown on the bending schedule.

Otherwise, the cover may not be obtained when the steel is positioned in the structure

fixed.

Bars should be bent cold with a slow and regular movement.

Never heat cold – worked bars.

Do not heat other bars without an engineer’s approval.

If bars have to be heated, do not exceed a cherry red colour.

Never cool heated bars by quenching in water.

If steel has been bent and then straightened, it should not be bent again at the same

point or near the same point.

Fixing Reinforcement

Reinforcement must be securely fined in the formwork so that the bars tire not

displaced by workers walking on them or by the placement of concrete. It is essential for the

safety of a structure to ensure that the correct size, shape and grade of reinforcement is used,

and that the reinforcement is fixed accurately and securely in the position specified. It is

essential that the concrete cover specified in the drawing is obtained in the order to protect the

reinforcement from rusting or chemical attack.

Where bars cross or where there is a lapped splice, bars should be tied together with

either soft iron wire (tie wire) or specially made wire ties( bag ties).The most suitable size of

wire is 1.6 mm diameter (do not use wire less than 1. 25 mm diameter). Bag ties can be

obtained in various lengths, but 150 mm is suitable for most purposes.

In our site, 1.6 mm diameter tie wire was used. This tie wire one roll was 25 kg .this

wire was cut four pieces for 10, 12,16 mm and three pieces for 20, 25,25mm. Bars were tied

double.



Important checks, during the reinforcement work are :

Check whether spaces of each reinforcement bar were in correct or not.(vertically&

horizontally)

Check weather availability of spacer bars of beams in required spacing.

Binding should be tightened properly.

Covering should be maintained.

In the case of double net , (such as in the case of a base) stools are used between the

two nets to get required space between them.

Under the bottom net cover blocks were used in required density to maintain the

bottom cover.

Laps can not be placed continuously.

REINFORCEMENT SCHEDULES &ARRANGEMENT

(1)Base slab

When rebar arrange for base slab, main bars and distribution bar (secondary

bars)should be considered. smallest span bars are main bars. Longest span bars are

distribution bars (secondary bars).In bottom, main bars should be below the distribution bars.

In top, main bars should be above the distribution bars.

(top)

Main bar distribution bar


For 10 ,12 , 16 mm, one piece approximately is 300mm

For 20, 25, 32 mm, one piece approximately is 400mm


Main bar distribution

(bottom)

When main bars or distributions lap, crank is not necessary. we should not lap more

than 50 % of the bars at the same cross section.

First line bar (FF)

Second line bar (NF)

Stools

Stools are used to separate the top reinforcement mesh and bottom reinforcement

mesh. Those should strength enough to bear the load without changing the gap of two layers.

12 mm or 16 mm bars are used to make the stools.

Stool height

Stool height = slab thickness-(top (main bar diameter +distribution bar diameter) +

bottom (main bar diameter +distribution bar diameter) + (2*cover))

(2) Column

A column is a vertical member carrying the beam and floor loading to the foundation

and is a compression member. Since concrete is strong in compression it may be concluded Department of Civil Engineering 21

Industrial Training Maga Engineering (pte)Ltd that provided the compressive strength of concrete is not exceeded no reinforcement will be

required. For this conditions must exist:

Loading must be axial.

Column must be short, which can be defined as a column where the ratio of its

effective height to its thickness does not exceed 12.

Cross section of the column must be large.

The minimum number of main bars in column should not be less than four for

rectangular columns and six for circular columns.

A minimum main bar diameter 12 mm.

The several shapes (square, rectangular, circular and L shaped) columns are used in

construction.

Stirrups for column

To prevent the slender main bars from buckling and hence causing spalling of the

concrete, links or binder are used as a restraint.

These should be at least one quarter of the largest main bar diameter.

Pitch or spacing not greater than twelve times the smallest main bar diameter.

All bars in compression should be tied by a link passing around the bar in such away

that it tends to move the bar towards the centre of the column.


Base

Main bar

Binder

Column with 4 main bars Column with 6 main bars

Main bar

Binder

Column with 8 main bars L shape column with 7 bars Circular column


anchorage

Column Elevation Column plan

In column bar schedule, crank is important . The slope of the inclined portion of a

cranked bar should be 1 in 10. crank the upper bars to extend the lowest bars. Starter bar

should be bended inside base slab. This anchorage length is 50 *Ø.

e.g. column bar diameter 32 mm

crank

crank length=10*32=320 mm

anchorage length= 50 * Ø

=50*32

=1600 mm

(3) Beam

400

In beam bar schedule, crank is important . The slope of the inclined portion of a

cranked bar should be 1 in 10. Anchorage length of beam depend on the beam height. E.g. if

beam height is 400 mm and cover 50 mm , anchorage length is 250 mm. This anchorage

length may be different. This anchorage length is no specific limitation.

In lightly loaded beams where compression reinforcement is not required. maximum

shear stirrups spacing is 0.75*d. where d is the effective depth of the member.


Strater

Industrial Training Maga Engineering (pte)Ltd In more heavily loaded beams where compression reinforcement is required,

maximum shear stirrups spacing is twelve-time size of smallest compression bar. The stirrups

should be at least one –quarter the size of the largest compression. Minimum clear spacing of

stirrups should be 75 mm, to enable a vibrator to be inserted.

* * * * *

* * * * * *

In continuous beam lapping should be avoided in *point such as in top, lapping

should be avoided in support point and in bottom, lapping should be avoided in mid span.

Because, that points are in tension. Bars are important member in tension

Tension bar

Tension bar

Hogging moment

Sagging moment

Bending moment diagram

Tension Compression

Compression Tension

Hogging moment sagging moment

In continuous beam, hogging moment and sagging moment are due to loads. In top of

the beam, tension is in hogging moment point and compression is in sagging moment point.

In bottom of the beam, tension is in sagging moment point and compression is in hogging


Industrial Training Maga Engineering (pte)Ltd moment point. Tension bars are used in tension points in top of the beam. such as Tension

bars are used in top of the beam in support point .Tension bars are not used in bottom of the

beam. When beam main bars spacing is greater than 250 mm, tension bar is used.

(4)Wall

Vertical bars Horizontal bars

When vertical bars or horizontal bars lap, crank is not necessary. we

should not lap more than 50 % of the bars at the same cross section.U bars are used to

maintain correct cover and to place bars in correct position. U bars are same diameter.this

may be as the horizontal or vertical.

Corner bar details in wall



T junction bars details in wall Opening bars details

L - Shaped bars are used in T junction and corner of the wall to avoid bursting or

cracking. Reinforcement in inner face should extend to outer face.

Nominal diagonal reinforcement should be provided in both faces around all openings

in a wall. If the walls are opening as shown above, the above detail can transmit only about

25% of the walls flexural capacity. Then, it is better to use “hair pins” .which has a higher

moment carrying capacity.

COVER BLOCKS

Reinforcement work cover block is very important part. Cover block is used to maintain the

space between shuttering and bottom of the reinforcement. Using grade 25 concrete with

6mm chips cover blocks (spacer) will be made as the given sizes. They are made up

cement :sand : chips = 1:1:1.

All formwork of reinforcement were supported on cover blocks. So that the

reinforcement can be completely enclosed by concrete and thus protected against corrosion

cover blocks may also be needed at the sides of the reinforcement to maintain the correct

distance from the side shuttering.

Covering sizes were specified in the drawings. Covering sizes are depend on,

1. Weather condition

2. Fire resistance

3. Grade of concrete

A part of binding wire was placed inside the cover block at construct level to tie with

reinforcement, otherwise it may move away from the exact location.

In our site 50 mm cover block was used in all places.

EXAMPLE:

Department of Civil Engineering 26T20-1-210

Industrial Training Maga Engineering (pte)Ltd T20-2-210

450mm

T20-3-210 T20-4-210

Column footing

Length = 27450 mm

Width = 2750 mm

Height = 450 mm

Cover = 50 mm

2650 mm

Main bar

200 200

Main bar length=2750-(2*cover)=2750-(2*50)=2650 mm

No of main bars

(27450-2*cover)/210=(27450-2*50)/210=130.24=131

Therefore no of main bars = 132 (131+1)

Distribution bar

5550 12000 11800

200 200

11800 12000 5550

200 200

distribution bar length=27450-(2*cover)=27450-(2*50)=27350mm

No of distribution barsDepartment of Civil Engineering 27


(2750-2*cover)/210= (2750-2*50)/210= 12.62=13

Therefore no of distribution bars = 14 (13+1)

Bars are in top and bottom

2/132/ T20 2650

200 200

2/14/ T20 12000

2/14/ T20 5550

200

2/14/ T20 11800

200

Structure Bartype Barno spacing No

of

bar

Cutting

length

(mm)

Total

length

(m)

Total

weight

(kg)

shape

column

footing

T20 - 210 264 3050 799.1 1970.58

T20 - 210 28 12000 336.0 828.58

T20 - 210 28 5750 161.0 397.03

T20 - 210 28 12000 336.0 828.58

Formwork

IntroductionDepartment of Civil Engineering 28

Industrial Training Maga Engineering (pte)Ltd This is temporary structural system, which provides casing to enable wet concrete to

attain the shape required. Formwork provides

1. Strength

2. Smoothness

3. Stiffness

4. Good shape at the concrete face

There are many objectives to be considered in selection of formwork

Concrete finish

Cost

Reuse

Logistics

Productivity

The concrete formwork and its labours are one of the highest profit risk area for the

contractor.

Additional requirements for good formwork

1. Joint should be simple

2. Must be easy to strip after concreting

3. Timber should not be too dry/ too wet (moisture content 15- 20%) with the surface

coated with mould oil

4. “formwork economy” in the design of structures

Use the same size column

At the formwork erect, consider the materials and methods will be required to

make and the removal

The formwork shall withstand and worst combination of the following loads

Total weight of formwork , reinforcement and concrete

Construction loads including dynamic effects of placing , compacting and

Construction traffic

Wind loads

Materials used for forms

Coated and uncoated plywood 4” *8” with 12 mm thick

GI pipe 48.6 mm diameter *2.4 mm thickDepartment of Civil Engineering 29

Industrial Training Maga Engineering (pte)Ltd Timber bearer 100 mm*100 mm

coupler

Procedure

4” * 8”, 12 mm thick plywood decking across 48.6 diameter * 2.4 mm thick pipes at

200 mm centers and spacing 1200 mm is placed across 100 mm * 100 mm timber bearers, is

supported by height adjustable vertical shores by Nppon Beatty. these shores are located in

rows at 1200 mm centers and 750 mm spacing , in each row . they are braced for lateral

stability in two directions at right angles, using 48.6 mm diameter GI pipes placed diagonally

and fixed together using GI pipe clamps. After erecting this arrangement, they are properly

leveled.

Details about shores

Type VS- 2

Closed height 2110 mm

Fully extended height 3480 mm

The safe working loads for axial loading are 20 KN in closed position and 15 KN in the fully

extended position

Total weight of the unit 13 – 16 kg

Material – High-tension steel

Lowest tube diameter 60.5 mm

Upper tube diameter 48.6 mm

Top plate – fork and flat

First, all the shores are adjusted roughly to required level, which is measured from off

lines. Then 100 mm* 100 mm bearers and 50 mm * 50 mm timber, 50 mm diameter GI pipe

are put after plywood is placed on that. Finally, they are properly leveled.

Coupler

To brace the shores for lateral stability in two directions at right angles, using 48.6 mm

diameter GI pipes fixed together with GI pipe couplers. Swivel, rectangular couplers are used.

The key factors concreting the workman ship of false work

The false work is used in accordance with the design , in particular as regards quality

of components, and setting out

Tolerances (± 3 mm)

All connections are properly constructedDepartment of Civil Engineering 30

Industrial Training Maga Engineering (pte)Ltd There is adequate safe access and working space

The base should be satisfactory

The vertical member of the structure should be located centrally on the sole plates on

base plates and fork head if size ≥ 100 mm

High tensile pin is commonly used but in some pins replaced by reinforce bars

Props should be erected as plump as possible (≤ 1.5º )

Over – extension of the screw, supporting the fork head must be avoided (≤ 300 mm)

Provide edge protection to all open side and holes in the decking as well as properly

constructed access to the working area to be prevent accidents

When concreting

Free fall of concreting is not allowed

Heaping of concrete within small area is not allowed and avoided

Prevent the shock loading

On the slab, materials should only be stored in areas designed by the engineer

Forms for columns

The column boxes are made of coated plywood (12 mm) sheets. In which two

Sides are cut to width of the column and other two are cut to the width plus 124 mm . which is

for fixing 2”*2” timber and twice the thickness of the plywood sheets. Already there sides are

fixed together and put it correctly along the setting out line, then closed other site properly.

They are tied using by separator, P-cones and supported by telescopic props and chains.

Finally it was plumped using 200-off lines of the columns edges.

Vertical GI pipe space 200-300 mm

Horizontal GI pipe space 600 mm

Space between slap and first GI horizontal support 200 mm

Column formworks are subjected to greater lateral pressure. Because of, its small cross

section area compared with the height. So column boxes must have tight joint to withstand

that high pressure. And also blowhole is made at the bottom to clean the inside surface before

concreting.

Baffle wall with column

Formwork for this component also similarly erected up to 600 mm from upper surface

of base slab, so that the height of kicker for wall will be 600 mm throughout from the upper

surface of the slab


Industrial Training Maga Engineering (pte)Ltd It is to be noted that the portion of the baffle wall directly connected with the main

periphery wall will not be constructed at this stage, which will be done along with the

construction of main periphery wall. Inner lengths of baffle walls, which are commencing

from expansion joints, are erected under the present stage.

Forms for walls

Wall thickness is maintained throughout the board by separators. This is easier then

column formwork arrangements. Wall is concreted part approximately 4’ or 8’ according to

their need (retaining wall 8’ 700 mm RC wall 4’). For next lift of formworks sponge is placed

between earlier concreted surface and new formwork, which is to be concreted to give proper

bond prevent leakage of concrete.



Form work for wall

P- Cones


Industrial Training Maga Engineering (pte)Ltd This is the old model Japanese system formwork arrangement and P-Cones types. 40

mm and 50 mm size P-Cones used according to load carrying capacity required. i.e. 50 mm is

used to bear where the high force occur.

Pee cone plan view

Rubble ring or welded

Metal plate

Form tie

Separator

Form panel 50 mm pee cone

Pee cone details

Preparation of formworkDepartment of Civil Engineering 34

Industrial Training Maga Engineering (pte)Ltd Before concrete is placed, the formwork should be cleaned of all dirt and construction

debris. All surfaces are coated with approved mineral mould oil.

225 mm

500 mm

500 mm

500 mm

500 mm

400 mm

300 mm

Wall formwork


48 mm Ø Gi pipe

Form tie

Pipe support(Adjustable)

12 mm plywood

50 mm*50 mm timber

Expansion joint

100 mm*100 mm Hard wood

100 mm*100 mm timber 2400 mm C/C

Industrial Training Maga Engineering (pte)Ltd For the key concreting vertical surfaces are prepared with the sharp cut of the original

ground. RRM was arranged places where ground condition is disturbed.

Formwork of the wall foundation was provided at the outer face of the foundation slab

that is inner face was covered by the previous concreted base surface. Along the wall line ,

wall kicker was arranged supporting the formwork with rebar .the kicker height is 150 mm

and at the wall center water bar was kept in positions by using water bar chips and wires so

that it was centered on concrete surface.

The formwork material is 12 mm marine coated plywood sheets for water structure

and supporting system is shown the sketch. To maintain the wall thickness separator were

used with 50 mm pee cone.

For our safe side, and to avoid water leaks through pee cones, rubber washer or

welded metal plate was used whenever fixing reservoir wall formworks. formwork for

reservoir walls was arranged as follows

1. 2.4 m 1st step

2. 2.4 m 2nd step

3. 3rd step with roof corbel

Removal of formworks

Formwork should not be removed until the concrete a sufficient strength to supports

its self –weight and any other load transferred. Form should be eased out carefully in order to

prevent the load being transferred suddenly to the partly hardened concrete.

Walls and columns (unloaded) 12-18 hrs

Tie beams (not load transfer) 24 hrs

Slap 21 days



CONCRETE

Concrete is a mixture of cement, fine aggregate, coarse aggregate and water. Two

essential properties of the hardened concrete are durability and strength. Both properties are

affected by the voids or capillaries in the concrete which are caused by incomplete

compaction or by excessive water in the mix.

According to the code BS 8110 the concretes are divided in to two classifications. The

first consists ‘designed mixes’, where strength is the main criterion specified, the design of

the mix is left to the supplier and compliance is judged on the basis of strength testing. The

second classification is that of ‘prescribed mixes’, where the cement content or mix

proportions are specified and it is the duty of the specifier to ensure that the mix specified will

give the required properties, including strength. With prescribed mixes, strength tests are not

used to judge compliance width the specification.

Transporting

Transporting of concrete will be done by 5m3 capacity concrete trucks from batching

plant number of concrete trucks will be increased by considering the volumes to be placed.

Concrete Placing

Placing of concrete will be done by using the concrete pump car and crane and bucket

considering the volume arid site conditions. Requited site test (slump test) will be arranged

for each trust to maintain the quality and cube will be casted for checking the strength of

concrete. Concreting will be started at one corner of the formwork and proceeded diagonally

without creating hardened edges.

Curing will be arranged for 7 days by using the gunny cloths and sprinkling of water.

Important things before concreting

Check the reinforce details , stools, services, cover, dimensions, etc

Check the levels of formwork, reinforcement

Check the reinforcement at all intersection whether the bars, links should securely tie

together with 1.6 mm soft iron wire .whether end of the wires must not point towards

the face

Check the support of the form work and construction joint key


Industrial Training Maga Engineering (pte)Ltd Check the surface (roughened joint surfaced which has to concreting) using

compressor

Wet the surface, formwork just before concreting

Check along construction joint whether properly chipped or not

Slump of the concrete

Concreting In Adverse Weather

No concreting will be allowed to take place in the open during storms or heavy rains.

In places where such conditions are likely to occur the contractor is to arrange for adequate

protection of the material, plant and formwork so that the work may be proceed under proper

cover. Where strong winds are likely to be experienced additional precautions to ensure

protection from driving rain and dust shall also be taken. During showery weather the

contractor shall ensure that work can be concluded at short notice by the provision of stop

ends. On no account shall work be terminated before each section between one stop end

another, is complete. Adequate covering shall be provided to protect newly placed concrete

from the rain.

Concrete at Night or in the Dark

Where approval has been given to carry out concreting operations at night or in places

where daylight is excluded, the contractor is to provide adequate lighting at all points where

mixing, transportation and placing of concrete is in progress.

Concreting in high Temperature

When the temperature of the concrete at the time of placing exceeds 32 0C, it may be

necessary for the contractor to take precautions, such as shading of aggregate stockpiles,

machinery, moulds and mixed concrete from the direct rays of the sun, cooling of the mix

constituents, machinery, reinforcement and moulds, and restricting the transportation time to a

practical minimum. The necessity for such precautions will be determined by the Engineer in

relation to the other factors affecting the heat of hydration, such as the characteristics of the

mix constituents, the nature of the particular pour and the method of curing to be adopted.


Industrial Training Maga Engineering (pte)Ltd HANDLING CONCRETE

When handling concrete the following are to be avoided:

• Delay

• Drying Out

• Segregation

As soon as the cement and water are mixed and concrete begins to harden and it does so more

quickly with:

• High concrete temperature (so keep the concrete cool in hot weather)

• Low water-cement ratio.

• Hot, dry, or windy weather conditions,

if it hardens too much it may rot be possible to properly place and compact it in the

forms, Throw the batch, out rather than try to doctor it. Never add water to hardened concrete.

There must be no delays in transporting, placing and compacting

Form B I 9(M) requires that t h e concrete be placed and compacted within the following

times from charging the mixer

Temperature32 C or less Temperature greater than 32 C

Mixed on Site 45 mins 30mins.

Ready-mixed I hour 45 mins.

No concrete with a temperature greater than 35 C should be placed in the job.

However, the supervisor should appreciate that from time to time specifications are

altered. So on each new job he should check the Job Document to ensure himself that there

have been alteration of which he is unaware


Industrial Training Maga Engineering (pte)Ltd Compacting

The object of compacting concrete is to ensure that maximum density is obtained,

and that no gaps are left between the concrete and the surfaces of the reinforcing steel and

formwork. A5% loss of compaction can result in a 30% loss of strength.

Proper compaction results

Maximum strength

Sound, watertight concrete

Sharp detail at concrete

Good surface appearance

Good bond with steel reinforcement

Sound protective cover for the steel reinforcement

The different method of compaction can be used such as

Hand compaction by rodding or tamping

Immersion vibrators (also known as internal or poker vibrators)

External form vibrators

Surface vibrators (vibrating screed boards)

Spinning (used only for concrete pipes and hollow circular piles)

Hand compaction

Rodding or tamping by hand can only be used for very small quantities of concrete

with a slump of 50-100mm. it may be used only for compacting minor works such as pipe

heads and not on bridges or culverts.

Immersion vibratorsThis type of vibrator may be mechanically driven by a petrol engine, Air-driven from a compressor and Electrically driven by small electric motor.

These machines have the following advantage

They are one of the most effective methods of compaction.Department of Civil Engineering 40

Industrial Training Maga Engineering (pte)Ltd The engines are small and lightweight thus enabling vibrators to be readily moved

about the job.

Relatively low purchase, running and maintenance cost.

Relatively easy to handle heads up to 70mm in diameter.

Wide range of heads to cover the wide variety of job conditions.

When vibrating the concrete certain procedures must be followed.

(a)Vibrate the concrete evenly

(b)Insert the vibrator vertically

(c) If more than one layer of concrete is being placed in the one operation, allow the vibrator

to penetrate right through the layer into the previous layer

(d) Withdraw the vibrator immediately motor begins to collect on the surface. This can

take from 5-10 second.

(e) Withdraw tile vibrator slowly (not faster than 100 rout per second) to allow the hole

left by the vibrator is close up.

(f) Work systematically, inserting tile vibrator at points about 500 poor apart (this will

vary with different consistencies of concrete and different sizes of vibrating head).

(g) Avoid using the vibrator to push tile concrete along the forms. the concrete should be

shovelled to its correct position if necessary.

(h) Do not allow the vibrator to touch the forms as a sand streak may result or the form

may be damaged.

(i) Normally the vibrator will be operating for about two thirds of the concrete is being

placed, though this time varies depending on the Characteristics of the mix and the

dimensions of the section being poured.

(j) When placing concrete in floors or deck slabs, it may be necessary to tilt the vibrator

provided it is not used to push the concrete.



Incorrect Correct

Incorrect Incorrect

Correct Incorrect Correct

Correct Incorrect

Poker using method

CURING

Reasons for curing


Previous layer Previous layer Still plastic

Previous layer

Previous layer (Still plastic)

Industrial Training Maga Engineering (pte)Ltd Correct curing is very important in order to get the maximum strength, water tightness and

wear resistance. The two things needed to provide conditions favorable for continued

hydration are

Adequate moisture

A favorable temperature

Loss of water from the surface of the concrete can cause hydration to cease, thus

preventing strength development. It can also cause shrinkage, which results in surface

cracking.

Low temperatures also cause hydration to slow down, and it is necessary to keep the

temperature well above freezing.

Advantage of curing

Increase the impermeability of concrete

Increase the durability of concrete

Continuous curing from the time the concrete is placed helps to ensure a hard, dence

surface and the risk of crazing and dusting

Curing methods

Concrete can be kept moist by a number of curing methods. in our site gunny cloths

were used for water curing.

Length of Curing Period

Form B19 (M) states that slabs shall be kept moist for at least 14 days, and other

concrete surfaces for at least 7 days.

Preventing plastic shrinkage cracks

This type of cracking comes times occurs soon after the concrete has placed. Plastic shrinkage

cracking is usually associated with hot-weather concreting. The following will increase

evaporation of surface moisture and therefore the possibility of plastic shrinkage cracking:

High concrete temperature

High air temperature

Low humidity

High winds

High strength, low slump concrete containing large amounts of cement.


Industrial Training Maga Engineering (pte)Ltd To minimize the possibility of shrinkage cracking the following simple precautions should be

taken:

Dampen the aggregates if they are very dry (but don't forget to allow for this

additional moisture when adding tile water to the concrete).

Avoid delays in transporting, placing and compacting the concrete.

Erect wind breaks.

Cover the concrete with wet covers or curing compound as soon as possible.

If cracking does occur before initial set, it should be rectified by hand working followed

by proper Curing.

FIXING WATER BARS

The sketchers of the fixing method of all type of water bars (Rear- guard type and

center bulb type) we enclosed.

BUT JOINT OR WELDING METHOD

Fixing clips or welding method to be arranged

Tools required - welding blade and anchoring clips.

INSTALLATION

Placing of water bars

Placing will be executed in accordance with the drawing on which the water bar profile and

the position required is marked level differences, bends, junctions, etc should be carefully

considered before placing.

Centrally placed water bars

(a). Fixing to reinforcement

Fixing clips are attached to the ends of the water bar. The fixing clips simplify the fixing of

water bars to the reinforcing steel by means of tying wires and thus ensure the water bars are

not displaced during concreting.

(b). Fixing to formwork

Formwork may be used. In this method allow one half of the water bar out and other half will

be casted. Water bars clamped between formwork.

PLACING THE CONCRETE

The water bar performs its function only if both sides are well embedded in the

concrete. The accumulation of coarse aggregates (honey combs) should be avoided around the

water bar to be fixed firmly.Department of Civil Engineering 44

Industrial Training Maga Engineering (pte)Ltd Placing of fresh concrete near the water bar requires core, as otherwise it will be

forced from its position by the pressure of the fresh concrete that is ends will fold up. To

present this the same concrete pressure must be present on both sides of the water bar.

CONCRETING THE SECOND STAGE

The water bar end will be checked for honeycombing and repaired if necessary. Bounding

agent will be wed for the concrete surface.

WELDING

Water bars are made form thermoplastic PVC and therefore allow an easy on site

welding. The ends are heated with welding blade mail the PVC melts (without burning or

charring). The welding blade is removed and molten ends are immediately pressed together.

The welded joint will be inspected after it has cooled.

VIBRATING OF CONCRETE EAR THE WATER BAR

Care will be taken to ensue that concrete is well placed and compacted around the

water bar area.

Wall Kickers

Proposed Details of the Kicker

(1)Height of the KickerDepartment of Civil Engineering 45

Industrial Training Maga Engineering (pte)Ltd According to section 5.7 of BS 8007: 1987, the height of the kicker should be at least 75

mm.

R.D. Anchor suggests on pages 17 & 82 of his well known book entitled, “ Design of Liquid

retaining Concrete Structures “, that the height of wall kicker should be between 100 to 150

mm.

In view of providing firm grip to wall formwork, we propose, the height of wall kicker should

be 100 mm.

(2)Shape of Kicker

R.D. Anchor states in his aforementioned textbook, if rebates are provided at construction

joints, cracks are formed invariably.

According to him, the most appropriate kicker is only a rectangular up stand without any

fillet and the free surface of the concrete must be finished to a compacted level surface.

We also prefer to introduce a rectangular up stand without any fillet as the wall kicker.

(3)Width of Kicker

Since the outer face of the external wall is inclined inwards, the width of the kicker at the upper

surface is slightly less than that at the lower end. The inner angle of inclination of the outer face

of the wall is 86.70º and the width at the upper surface of the kicker is 5.8 mm less than that at

the bottom therefore the width of the kicker at the bottom is 750 mm [wall thickness]. But the

width at the upper end of the kicker is 385 mm.



]

Removing of pee cone

Pee cone was removed after someday concreted.

Then that area was cleaned properly.

Motor was applied into the area (cement : sand = 1: 1) Department of Civil Engineering 47

Industrial Training Maga Engineering (pte)Ltd White cement mixed with water and applied above the motor (this is applied for

colour)

Top of the roof

200 mm pebble layer

50 mm benching concrete 4 mm water proofing membrane

Roof slab

Water proofing membranes are used to prevent water movement towards the inside of

the structure. There are different kinds of the water proofing membrane (e.g.

Xypex).

Roof slab concrete was grade 35 and benching concrete was grade 20. benching

concrete is used to protect the water proofing membrane from its failure by external

activities.

Pebble layer is used to prevent heat installation (dolomite).

Leakage checking

After finished reservoir construction, reservoir was filled by water.

Checked water level for 7 days on morning and evening

Found out leakage in some place

First, that area was chipped after that water plug (one type of cement) mixed with

water .then applied in that area.

Test for concrete

Slump test

Cube test

Slump test

The workability of concrete is the ease with which it may be placed and

compacted. The slump test is used to indicate the likely workability of a concrete mix.


200mm

Industrial Training Maga Engineering (pte)Ltd Concrete is tested to control workability (consistency). The consistency of the concrete is

checked by means of slump cone. The slump test measures the consistency of concrete. It is a

simple means of ensuring that the concrete on site is uniform.

Once the slump of a particular concrete mix has been determined, the slump test

indicates whether or not the materials in different batches are still being mixed in their correct

proportions. If the slump alters from batch to batch, it is most probable that the water content

is varying from batch to batch. However, variation in slump can also be caused by alterations

in aggregate grading or cement content. The apparatus are used in testing such as

Standard slump cone (100 mm*200 mm*300 mm)

The mould shall be of a metal other than brass and aluminum of at least 1.6 mm.

(or 16BG) thicknesses. The top and bottom shall be open and at right angle to the axis of the

cons. The mould shall have a smooth internal surface. It shall be provided with suitable foot

piece and handles to facilitate lifting it from the moulded concrete test specimen in a vertical

direction as required by the test. A mould provided with a suitable guide attachment may be

used.

Pointed steel rod: (The tamping rod shall be of steel or other suitable material, 16 mm

in diameter 600 mm long and rounded at one end

A rule or meter tape

Scoop

Smooth flat plate: The base plate shall be of steel or other suitable material, smooth

rigid and with non-absorbent surface.

The test must be carried out on a level non-absorbent surface. The inside surface of

the cone must be clean and free from hardened.

Procedure of this test In first of all the inside of the slump cone was moistened.

The cone was hold in place on the prepared level surface by placing a foot on each

foot rest.


300 mm

100mm

49

Industrial Training Maga Engineering (pte)Ltd The cone was filled for three layer, each about one-third of volume, by scooping

concrete from sample.

Each layer was rod exactly 25 times by steel rod. Make sure that the rod penetrates

to the layer beneath each time, and that the strokes must be distributed over the

surface.

Top surface was stroked off by the rod so that the cone was exactly filled

Any surplus concrete was removed from around the base.

The cone was lift carefully but firmly straight up so the concrete was allowed to

subside. Then the cone was placed invert alongside the concrete and the rod was

placed across the top of it.

A rule (meter tape) was used to measure the amount of concrete has subsided.

Note: if the concrete collapses sideways when the cone is lift, repeat the test.

Allowable slump range is different to every grade of concrete.

Grade of concrete allowable slump range

Grade 15 100+/-10

Grade 20 120+/-10

Grade 25 120+/-10

Grade 30 120+/-25

Grade 35 120+/-25

Grade 35A 120+/-25

Grade 50 120+/-25

Cube Test

a) Size of Test cubes

The standard size of cube shall be 150 mm*150 mm *150 mm, but may be 100 mm*100

mm* 100 mm. cubes may be used, if the minimal maximum aggregate size does not

exceed 25 mmDepartment of Civil Engineering 50

Slump

Industrial Training Maga Engineering (pte)Ltd b) Compacting test cubes

The test specimen shall be made as soon as practicable after sampling, in such a way as to

produce full compaction of the concrete with neither segregation nor excessive laitance.

The mould shall be filled in layers approximately 50 mm depth and each layer shall be

compacted. After the top layer has been compacted the surface of the concrete shall be

finished level with the top of the mould by means of a trowel.

When compacting by hand, the standard compacting bar shall be used and the storks of

the bar shall be distributed in a uniform manner, over the cross sections of the mould.

The number of strokes per layer, required to produce the specified condition will vary

according to the type of concrete, but in no case shall the concrete be subjected to less than 35

storks per layer for 150 mm.

c) Curing Test cubes

Specimens made on site.

Immediately after they are made, the test specimens shall be stored in a place free from

vibration, under damp matting or other suitable damp material, completely covered with

polythene or other impervious sheeting, at temperature of 20 +- 5 C, for 16 to 24 hours, form

the time of adding water.

If the concrete has not achieved sufficient strength, to enable remoulding to be carried out

within the stated period, the remoulding shall be delayed for a further 24 hours, but this fact

shall be stated in the text report. During this further period, the specimens shall be stored in

the moist air conditions stated

After moist curing, the specimens shall be marked for later identification, removed form

the moulds and unless required for test within 24 hours, immediately submerged in a water

tank until they are transported to the testing laboratory.

One or more tanks can be used, containing clean water, renewed at least once a month and

maintained at a temperature of 20 +- 2 C on site.While the specimens remain on site, records

of the daily maximum and minimum air and water storage temperatures shall be kept with

maximum and minimum thermometers or with continuous recording instruments.

The specimens, well packed in damp sand or wet sacks and enclosed when necessary

in a polythene bag or sealed container, shall be sent to the testing laboratory, when they are

not less than 3 days, nor more than 7 days old, to arrive there in a damp condition not less

than 24 hours, before the time of test.

On arrival at the testing laboratory, the specimens shall be stored in water, maintained

at a temperature of 20 +- 1 C, until the time of test. The specimens shall not be allowed to

become dry at any time, until they are tested.Department of Civil Engineering 51

Industrial Training Maga Engineering (pte)Ltd Specimens to be tested at 24 hours, shall be stored for this period in the moist air

conditions stated and remoulded just before test

d)General

The characteristic strength of concrete, on which the structural design is based is that, 28

day cube strength below which, not more than 5% of the test results may be expected to fall

In order to get an idea of the quality of the concrete sooner, compressive strength test at 7

days may be used, to test compliance with the specified characteristic strength.

For this purpose, the 7 days strength may be taken to be 2/3 of the 28 day cube strength.

The rate of sampling shall generally be as given below, unless other-wise decided by

the officer In charge.

One sample shall be taken from any one batch, selected randomly to represent an average

volume of not more than 20 cubic meters, 20 batches or ¼ of the total quantity of concrete

under consideration for testing, whichever is the lesser volume, but not at a rate less than 1

sample per day per grade.

d) Testing Plan

Each cube shall be made from a single sample taken from a randomly selected batch of

concrete. The samples shall be taken at the point of discharge from the mixer or in the

case of ready mixed concrete, at a point of discharge from the delivery vehicle.

Number of cubes needed

In site number of cubes is varied according to the main contractor or client

requirement.

0-10 m3 3 cubes in which, 1 cube for 7 day testing and 1 cube for 28 day

10-25 m3 6 cubes in which, 2 cubes for 7 day testing and 2 cubes for 28 day

over 25 m3 9 cubes in which, 3 cube for 7 day testing and3 cube for 28 day

Information about machinery / equipment Overview

The size of project.

The topography.

Volume of earth to be removed any other detailed influence the choice of type.

In general, the earth moving machines are used for ground leveling and bulk earth

moving whilst the static-type machines are usually operated on specific tasks. In both


Industrial Training Maga Engineering (pte)Ltd civil engineering and building work the initial construction site is often uneven and

requires leveling. The most suitable plants is generally selected moving machines.

Factors affecting equipment selection

Selecting the correct equipment for the job ideally forms part of the construction planning

process. Equipments were choused for this task after analysis of many interrelated factors.

I. The function to be carried out.

II. The capacity of the machine.

III. The cost of method and cost comparison with other method

IV. The limitation of the method.

V. The method of operation :- the distance and direction of travel, speed, and frequency

of movement, sequence of movement, state of ground, etc,

VI. Etc

Used some equipments in site

1. Backhoe (Excavator)

2. JCB

3. Bulldozer

4. Concrete trucks

5. Pump car

6. Breaker

7. Bar bending, cutting machines

8. Compressors

9. Lorries and trucks (wagon)

Backhoe (Excavator)

Hydraulically operated backhoe is used to have the shape of the excavation curve varied

to suit the situation and allows the limit of the excavation to approach much nearer to the

tracks of the machine due to both arm the bucket are indecently controlled by means of

separated hydraulic rams and also additionally the variable force available with hydraulic

powering gives the machine a much increased capacity.

Used situations

Excavation of large earth materials

Shoring removal, installations

Loading of material into wagon

To place the concrete when absence of crane, pump car but to small area

To lift goods, etc as a small crane

Etc

Wheeled backhoe / Loader (JCB)Department of Civil Engineering 53

Industrial Training Maga Engineering (pte)Ltd Much of the work is done using this machine.

Height (up to -2.9 cm, clear height -3.7m) For trench excavation we used two size buckets

(inter changeable)

Used situation

Excavation of train trenches

Loading of loose material in to wagon

To lift goods as a small crane

As a bulldozer (stripping the top soil, mud, shallow excavation, etc)

Transport the material within short distance

Stock pilling of materials

Etc

Bulldozer

This is very versatile machine and was used frequently. The dozer is normally

operated with a straight blade fixed perpendicular to the line of movement to push the

material forward or angled to move the soil to the side. Crawler type dozer was used in our

site due to

Give low pressure to the base

Not stability problem then wheel type(uneven surface)

Etc

Used situation

Stripping top soil and clearing vegetation

Shallow excavation

Spreading and grading of soil

Ripping

Concrete trucks

In which fully mixed concrete is loaded into the truck mixer at the batching plant.

During transportation to the site the drum revolving at1-2 revolutions per minute agitates the

mix. On arrival the mix is finally mixed by increasing the drum’s revolutions to between 10 to

15 revolutions per minute for a few minutes before being discharged. 3-5 m3 trucks are used.

Mixture drum is inclined 16o.

Lorries and trucks (wagon)


Industrial Training Maga Engineering (pte)Ltd Earth moving trucks are used to transport material not only longer distance but also

within the site. They are usually loaded by an excavator, but sometimes, in exceptional cases

by the JCB also. Actually the choice of system in transporting material form the loading point

depends on many factors including.

a) Site conditions

b) Volume of material to be moved

c) Type of material

d) Time available

e) Road condition

f) Distance

g) Etc

Pump car

The transport and placing of concrete by pump car is an increasingly popular method

because

a) It is very fast

b) Efficient

c) Little waste of concrete

d) Can prevent the segregation

Etc

Considering points

The speed of the pumping(10-90m3/h)

Should be pump able concrete where slump and sand grading is important

Supply of concrete to the pump should be adequate for the pump’s capacity

Maintaining continuously flow of concrete

Breaker

The most common pneumatic tools used in building are the breaker. Which is used

basically for breaking up hard surfaces. This tool needs a supply of compressed air as their

power source.

Steel bending, cutting machine

which is used to bend , cut the reinforce bars. This is one of management planning.

steel yard is in another place and near the site . if the yard is out of the site then we should

have transport facility, time wasting, etc.

Gapugala Batching plant


Industrial Training Maga Engineering (pte)Ltd Gapugala batching plant was temporarily built to supply concrete to that project and

follow Japan standard. This plant supply the concrete to Gapugala reservoir, kowlhena

reservoir, Hallolugoda reservoir, Magoda reservoir , intake and NOH .

Plant cement container 58 metric tones

Water tank 150 letters

Cement

Procedure

First sand is conveying belt to the “scale” which is controlled automatically by lever

principal.then metal is passing to that it “scale” after sand conveyer stopped. Automatically

calculatethe total weight (sand +metal) and stop when the required weight passed. Both sand

and metal mix together and pass it to the “pan/drum mixture”. At the same time cement and

water also come to this “pan” and stop when the required weight collected . at once 1 mз can

able to mix . I.e. for 5m3 concrete preparation, five times is necessary.

Mixing speed -20 rpm

For prepare 1 m3, time required -min

Fully prepared mix is then transported to site using concrete trucks. In plant , one

cube is casted per 30m3 concrete to checking strength and also checked the slump from every

truck concrete mixture . G15, G20 ,G25 ,G30,G35,G50 concrete is prepared to supply . if any

cube fails from its required strength then core test should be done

Grade of concrete

The standard recommended compositions are as follows and Concrete grade was

decided according to the requirement of the structure. The basis and the method of

proportioning of concrete are depending on the grade of concrete and the structural

importance of the members. In this concretes Pozzolith300R, AEA303A and Rheobuild 561

are used as admixtures. Pozzolith300R is to change porosity, AEA303A is to change air voids

and Rheobuild 561 is to change rigidity.

SAFETY PROCEDUREWhich is the important consideration point in construction sites where dangerous

accidents take place ,such as handling of huge machines, electrical works, working at higher

elevation, etc.before happen accident , we should be aware of it . some of those are given

below.

Wear helmet, safety foots, etc always at the site


Industrial Training Maga Engineering (pte)Ltd Wear safety belts when working at higher elevation

Not allow to work underneath when working is going on at higher elevation directly

Provide ladders for the access of the higher elevation

Keep first – aid person at the site always

Put safety barriers/ barricades to indicate unsafe areas

Put “SAFETY FIRST” board

Put safety nets/ fans around the scaffolding

Monitories the electrical supply wires, switches safety

Never use the florescent bulb without safety glass

Etc



-1.0 INTRODUCTION

I have been appointed to do the training in Tudawe Brothers Limited and I have been

working first 13 weeks at the site ‘Little Sisters of the Poor ‘at Maradana. The site is located

next to St.Josephs College. Then after 9 weeks, I have been working at the site ‘Godagama to

Malamba road project’ which site office is in Aturugiriya. Head office of the organization is

located at 505/2, Elvitigala Mawatha, Colombo 05.Department of Civil Engineering 58

Industrial Training Maga Engineering (pte)Ltd 1.1 ABOUT THE ORGANIZATION

Tudawe Brothers Ltd. (TBL) is one of Sri Lanka's premier construction engineering

companies, established in 1942 and incorporated in 1947.

Its areas of construction are high rise office complexes, shopping malls, luxury

apartments, industrial estates, educational & healthcare institutes, highways & bridges and

water supply systems. Tudawe Brothers Ltd remains in the field of housing construction

where it has built over 1500 personal housing units, of which approximately 200 comprise

modern up-market apartments.

Given its commitment to excellence, two associates were established to

complementing the work done by Tudawe Brothers Ltd. Tudawe Trading Company Ltd

provides support services related to electrical , air conditioning and fire protection and

Universal Interiors (Pvt) Ltd supplies and installs architectural aluminium systems for

buildings.

Tudawe Brothers Ltd has won construction excellence awards in 1991, 1994 & 2001

and Merit Award by the Institute for Construction Training and Development (ICTAD)

in1996. Also Tudawe Brothers Ltd is the first local company to be awarded ISO 9002

certification for Building Construction & the Manufacture of Ready Mixed Concrete, by an

internationally accredited registrar Det Norske Veritas.

ICTAD grading of the company :

M1 - Building construction-

M1 - Highway construction

M1 - Water supply and drainage

M3 - Bridge construction

M5 - Irrigation and land drainage

M5 - Dredging and reclamation

F1 - Finishing trades

EM1 - Electrical and mechanical works under Tudawe Trading Company Ltd.

1.2 ON GOING PROJECTS

1. Malambe to Godagama road project ( Project Cost is Rs. 370 Million )

2. Ambathale to Kaduwale road project (Project cost is Rs. 110 Million )

3. Little Sisters of the Poor (Project Cost is Rs. 409 Million )


Industrial Training Maga Engineering (pte)Ltd 4. Ascon Appartments ( Project Cost is Rs. 247 Million )

2.0 ABOUT THE LSP (BUILDING SITE) ORGANIZATION

2.1 ABOUT THE SITE DETAILS

Site Location No:204, T.B.Jayah mawatha, Colombo-10

Client Little Sisters of the poor



Architect Arch. H.M.R.B.Herath

Consultants LSP Design Group & Multi consultancy services

Contractor Tudawe Brothers Ltd.

Project Cost Rs. 409 Million.

Period 15 months.

Table : 2.1 About the building site details

2.2 THE ORGANIZATION CHART


Project Director

Project Co-Ordinator

Site ManagerProject Engineer Planning EngineerSite EngineerTechnical OfficerSupervisor Project Quantity SurveyorSite Quantity Surveyor SurveyorSite SurveyorAssistant Surveyor Store KeeperAssistant Store Keeper


Figure :2.1 Structure of the organization for the building site



2.3 JOB FUNCTIONS

Project co-coordinator1. Reports to project manager

2. Overall planning, co-ordination of site activities, site management and budgeting.

3. Leads a team of engineers, site quantity surveyor, surveyors and quality assurance

co-ordinator.

4. Liaises with client, consultants and local authorities.

5. Attends all client or consultant meetings.

6. Co-ordinates nominated subcontractor activities.

Site manager1. Reports to project coordinator.

2. Plans and co-ordinates site activities and with the site staff.

3. Monitors work programme and quality control.

4. Liaises with client, consultants and local authorities

5. Attends all client or consultant meetings.

6. Liaises with sub-contractors.

7. Implementation of safety measures.

8. Liaises with nominated sub-contractors.

9. Liaises with manager planning ad development and prepares micro programmes.

10. Preparation of three monthly programme and monitors programme.

Site planning engineer and engineer in-charge

1. Reports to site manager.

2. Checks discrepancies between structural and architectural drawings.

3. Counter checks alignment and levels by surveyor.

4. Checks structural drawings for discrepancies.

5. Liaises with consultant engineer on technical matters.

6. Monitors work progress and quality control.

7. Preparation of shop drawings for temporary works.

8. Preparation of bar bending schedules.

9. Documented and drawing control.



Site quantity surveyor

1. Reports to site manager.

2. Evaluates and prepares progress payments to sub-contractors.

3. Assist in preparation of the monthly valuation and estimates of variation orders.

4. Prepares material forecasts and weekly requisitions.

5. Verifies material requisitions.

6. Prepares daily reports.

Technical officer

1. Sets out alignment and levels.

2. Checks discrepancies between structural drawings and issues RFI.

3. Counter checks alignment or levels by surveyor.

4. Monitors work progress and quality control by using inspection and test plans.

5. Records daily works and submits to R.E for certification at the end of the day.

6. Act as a member of the site safety committee.

7. Submits of materials for approval from consultants.

8. Maintains concrete cube testing reports.

Supervisor

1. Reports to site engineer or technical officer.

2. Sets out alignment and levels.

3. Labourer supervision and ensuring the quality of works.

4. Counter checks alignments or levels by surveyor.

5. Monitor work progress and quality assurance by using inspection and test plans.

6. Records daily works.

7. Act as a member of the site safety committee.

Site surveyor1. Counter check setting out or level done surveyors.

2. Monitor progress and quality control by inspection and test plan.



Store keeper

1. Maintaining stock controls (consumables and nonconsumables).

2. Controls or checks quantity and quality of materials delivered.

3. Ensures adequate inventories and stocks are available to meet the sites planned

activities.

4. Prepares daily and monthly records for materials received at site.

5. Inventory control of plant, machinery and equipment, their usage at site and

maintaining records of repairs and services.

6. Inventory control of nonconsumables.

7. Prepares Good Received Note (GRN).

8. Prepares goods issued note.

9. Prepares transfer notes for materials transferred out from the site.

10. Prepares material reconciliation report.

11. Liaises with purchasing department.



3.0 FORM WORK

One of the easiest and most obvious ways of judging whether a concrete job is

satisfactory or not is by its finished appearance.

The formwork and the way it is made and used play a greater part in the finished

appearance than anything else. It is made from expensive materials by skilled men and the

total cost of fabricating, erecting and striking formwork is often comparable with the concrete.

Apart from the appearance considerations, formwork usually needs to be used many

times and this can only be done if it is carefully and properly handled, cleaned and stored- be

it of timber, steel or other material-as otherwise time and money will be wasted and the job

will not progress smoothly.

3.1 REQUIREMENTS FOR FORMWORK

o It must be built and erected so that the required shape, size position and finish of

the concrete are obtained.

o It must be strong enough to take the pressure or weight of the fresh concrete, and

any other loads, without distortion, leakage, failure or danger to workmen.

o It should be designed and constructed so that it can be easily and quickly erected

and struck, so saving both money and time.

o It must be able to strike without damage to the concrete or to itself.

o It must be able to handle using available equipment or to be manhandled if

necessary.

o The arrangement of the formwork must provide access for the concrete handling

and placing and, equally important, all the necessary safety precautions relating to

working areas and platforms must be followed.

o Joints between members must be tight enough to prevent grout leakage.

3.2 TIME OF REMOVAL

Form work of beams and slabs should not be removed until the concrete reaches a

sufficient strength to support its self weight and any other loads transferred.


Industrial Training Maga Engineering (pte)Ltd Forms shall be eased out carefully in order to prevent the load being transferred suddenly to

the partly hardened concrete.

The most common fault with release agents is for too much to be put on: this can stain

the concrete. On the other hand, if not enough is applied, striking is made difficult and both

the concrete and form face can be damaged.

The right amount is thin film applied uniformly by brush, roller or best of all spray. if

by mistake too mush is applied wipe off the excess with a clean rag. Never dilute or mix

different release agents together.

3.2.1 THE MINIMUM PERIOD TO REMOVING FORMWORK

Formwork can be struck when the concrete has gained enough strength to be self –

supporting and also to carry any other loads that may be put on it.

The job specification will normally give guidance on when forms can be struck and

these times may be governed by the size and shape of the member, the concrete mix, and the

weather (Table: 3.1).

Part of structure Period for ordinary Portland

cement without admixtures

Sides of foundations, columns, beams and walls 24 hrs

Undersides of slabs up to 4.5 m span 7 days

Undersides of slabs of above 4.5 m span and

undersides of beams and arches up to 6 m span.

14 days

Cantilever slabs and beams 21 days

Domes , shells and other structures of special nature As per written instructions of

engineer in charge.

Table : 3.1 Minimum period for removing form work



3.3 FORM WORK FOR BEAMS AND SLAB

Form work for beams and slab are generally erected at once. Horizontality of the

beams and slab form work is an important parameter therefore we need to make more

attention on the process of levelling the formwork .In our site we have used a level machine

for levelling the form work of beams and slab (Figure: 3.1).

4200

Level Machine

Figure : 3.1 Levelling the beam and slab form work

X = known height (marked on the column normally 1000 mm level line)

Y = beam height

Z = slab thickness

Therefore while levelling the beam the staff reading should be = 4200 - ( X + Y + 15 )

Therefore while levelling the slab he staff reading should be = 4200 - ( X + Z + 15 )

plywood thickness is 15 mm.

Generally supports (false work) of the formwork raised or lowered to get the required

reading and by this process the form work for the slab and the beams can be easily levelled.

The figure : 3.1 shows the detail description of the form work for the beam and slab.


Floor level

Y

15

beamZ

X

staff

Floor level


4.0 REINFORCEMENT

Reinforcement is used to carry tensile stress as well as compressive stress.

Reinforcement bars carry tensile stress only, where as compressive stress will be carried by

both reinforcement bars and concrete, which is depending on the situation of carrying.

Normally steel bar is used as reinforcement because it has enough strength and both steel and

concrete has nearly the same thermal coefficient. In early days wooden bar was also used for

this purpose.

The reinforcement detail are mentioned in the reinforcement drawing. After that the

following checks have to be done.

1. Spacing

2. No of strips

3. Lap length

4. Starter bars for columns

5. Cover blocks

If there are any construction joints, they should be chipped to bond properly.

4.1 INDICATION OF REINFORCEMENT IN DRAWING

Engineering drawing is a language to communicate with details. Therefore there is a

standard to indicate the reinforcement details in drawings such as,

4Y 16-07-125T

This means that

‘4’ - No of bars

‘Y’ - Indicate for Tor steel

’16’ - Indicate the diameter of the bar in mm

‘07’ - Indicate the bar mark

‘125’ - Indicate the distance between two bars

‘T’ - Indicate the position of the bar (top bar)



4.2 COVER BLOCKS

Reinforcement work cover block is very important part. Cover block is used to maintain the

space between shuttering and bottom of the reinforcement. They are made up to 1:2 cement

mortar.

All formwork of reinforcement were supported on cover blocks. So that the reinforcement can

be completely enclosed by concrete and thus protected against corrosion cover blocks may

also be needed at the sides of the reinforcement to maintain the correct distance from the side

shuttering.

Covering sizes were specified in the drawings. Covering sizes are depend on,

1. Weather condition.

2. Fire resistance

3. Grade of concrete.

A part of binding wire was placed inside the cover block at construct level to tie with

reinforcement otherwise it may move away from the exact location.

In our site 30mm cover block was used in all places.

4.3 BAR BENDING WORK

In our site usually bar bending is done by bending machine and cutting machine. But for

minor works it can be done manually with the help of cutting lever. Skilled bar benders are

involved in this process. The bar bender did his job according to bar schedule which was

given to him. It includes,

Size of bar

No of bars

Dimensions

Bending length

Crank length position

4.4 PLACING OF REINFORCEMENT

All reinforcement should be placed in correct position as shown in drawing. It should

not be allowed to move when concreting.


Industrial Training Maga Engineering (pte)Ltd 5.0 CONCRETE

Concrete is a mixture of cement, fine aggregate, coarse aggregate and water. Two

essential properties of the hardened concrete are durability and strength. Both properties are

affected by the voids or capillaries in the concrete which are caused by incomplete

compaction or by excessive water in the mix.

According to the code BS 8110 the concretes are divided in to two classifications. The

first consists ‘designed mixes’, where strength is the main criterion specified, the design of

the mix is left to the supplier and compliance is judged on the basis of strength testing. The

second classification is that of ‘prescribed mixes’, where the cement content or mix

proportions are specified and it is the duty of the specifier to ensure that the mix specified will

give the required properties, including strength. With prescribed mixes, strength tests are not

used to judge compliance width the specification.

5.1 GRADE OF CONCRETE

The standard recommended compositions are as follows and Concrete grade was decided

according to the requirement of the structure. The basis and the method of proportioning of

concrete are depending on the grade of concrete and the structural importance of the

members.

1) Grade 10 mix

Grade 10 mix is obtained by the following proportion Cement: Fine aggregate: Coarse

aggregate=1:4:8

Water added (roughly)=32 liters Expected strength= 10 N/mm2

2) Grade 15 mix

Grade 15 mix is obtained by the following proportion, Cement: Fine aggregate: Coarse

aggregate=1:3:6

Water added (roughly)=32 liters

Expected strength=15 N/mm2

Mainly used for screed but not used for reinforcement concrete.

3) Grade 20 mix

The following proportion obtains grade 20 mix

Cement: Fine aggregate: Coarse aggregate=1:2:4

Water added (roughly)= 25 liters


Industrial Training Maga Engineering (pte)Ltd Expected strength= 20 N/mm2

Mainly used for screed

4) Grade 25 mix

The following proportion obtains grade 25 mix, Cement: Fine aggregate: Coarse

aggregate: 1:1.5:3

Water added (roughly)=23 liters

Expected strength=25 N/mm2 Mainly used for walls

5) Grade 30 mix

The following proportion obtains grade 30 mix

Cement: Fine aggregate: Coarse aggregate=1:1:2

Water added (roughly)=20liters

Expected strength=30 N/mm2

Mainly used for columns, slabs, and basement of foundation

The above-mentioned proportions of concrete aggregates are based on volume measures. One

bag of cement is 50kg, which is equivalent to 0.035. This cement volume was taken as one

unit volume and other aggregates were then mixed on basis of volume according to the grade

of concrete. To do this task unit volume and other aggregates were then mixed on the basis of

according to the grade of concrete .To do this task unit volume boxes were made which

internal dimensions were 400mm*300mm*250mm. (I .e The volume of unit volume box was

0.035m3). For example for grade 15 concrete mix, 3 boxes of fine aggregates and 6 boxes of

coarse aggregates was added to 1 bag of cement.

Here it should be noted that the relative proportion of fine aggregate to coarse

aggregate is generally kept at a constant ratio 1:2

5.2 CHECKS BEFORE CONCRETING

o Thorough inspection should be made for the formwork by the supervisor before

concreting. The inspection should include,

o Are the loads and wedges secure against loosening due to vibration?

o Has the right number of ties been used and are they in the right places?

o Are all the ties properly tightened?

o Are all inserts, void formers cast-in fixings in the right position and secure?

o Have the stop-ends been properly secured?

o Have all the joints been sealed to stop grout loss?

o Is the formwork is correctly aligned and levelled?Department of Civil Engineering 72

Industrial Training Maga Engineering (pte)Ltd o Are all the props plumb? And at the right spacing?

o Are the pops and struts properly tightened up and locked?

o Can the formwork be struck without damaging the concrete?

o Has the release agent been applied? is it the right one?

o Is the reinforcement correct?

o Has the reinforcement the right cover? are there enough spacers?

o Are the forms clean and free form rubbish or odd bits of timber or metal? Tie-wire

droppings will cause a stain on the face of the concrete.

o Is there are proper access for concreting and compaction?

o Can any necessary inserts or box outs be done when concreting?

o Is the curing equipment and are covers ready?

The above checks combined with general check on the security and tightness of the forms

can save accident and injury or even loss of life.

5.3 TEST FOR CONCRTE

Normally two types of test were done for concrete in our construction site. They are,

1. Slump test.

2. Cube test.

5.3.1 SLUMP TEST

The slump test is the simplest test for testing workability at the site. The height of the slump is

depending on the amount of water in the mix. The nature of the aggregate also influence to

the slump.

The main apparatus are used in testing,

1. Slump cone.

2. Smooth flat plate.

3. Tamping rod 600 mm long and 16 mm diameter

At first the cone and late were cleaned and the cone was placed on a metal surface. Then the

concrete was put as a three layers and each lager was compacted 25 times with the rod. After

filling three times, the cone was removed immediately and kept that side of the concrete cone

and the rod was kept on the cone. Finally the slump was measured between the top of the cone

and highest point of the concrete. After the finishing the test all the apparatus were cleaned

with water and dried.



5.3.2 CUBE TEST

This test was carried out to determine the compressive strength of the harden

concrete. Casting the test cubes was made in special mould, which is 150 mm x 150 mm x

150 mm., either site mix or ready-mix, it is very essential to confirm the strength of concrete.

Because the strength of concrete is not only depending on the proportions of cement and

aggregates but also depending on the quality of materials, amount of water added, size of

aggregates etc. The very common and easiest method to test the concrete at site is the concrete

cube test. The concrete cube test was done to the grade 25 concrete (1:1.5:3) the method is as

follows,

5.3.2.1 Preparation of moulds

The standard concrete moulds were checked whether they were clean and dimensionally

correct.

The moulds were detached and their internal surfaces

Then they were again assembled and grease was applied to the internal surfaces.

5.3.2.2 Preparation of cubes

Concrete samples were randomly collected

The first concrete layer was placed into mould (approximately 1/3 height of the

mould)

35 blows were given to that layer

Then the second layer of concrete was placed to the into the mould (approximately 2/3

height of the mould)

Finally the third layer of concrete was placed to the rest of mould and 25 blows were

given to that layer.

Then the top of the concrete surface was smoothened and the location of site were

written on the cube

Similarly 8 cubes were prepared

All the cubes prepared were kept at carefully



5.3.2.3 Testing of cubes

Next day moulds were removed and all the cubes were fully submerged in water.

After 7 days, cubes were taken from water and 4 cubes were tested for strength After

28 days, the rest of 4 cubes were tested for their strength to find the compressive

strength of the test cubes, gradually increasing.

Compressive force is applied to each test cubes separately by hydraulic mechanism. The

crushing strength is taken as the compressive strength, which can be directly red from the dial

gauge. Finally the average strength is taken as the compressive strength of the test cubes.

5.4 CONCRETING

Some experienced in the construction of formwork, preferably a tradesman, should

always be standing by when the concrete is being placed. He should have a supply of suitable

materials such as props, bolts etc. to handle dangerous situations. Check cracking, excessive

deflection, level and plump and any movement. Concrete should be deposited at, or as near as

possible to, it’s final position.

The concrete should be placed in uniform layers. Avoid placing it in large heaps or

sloping layers because there is always a danger of segregation, especially with mixes tending

to be uncohesive.

In walls and columns no layer should be more than about 450 mm thick. With layers

thicker than 450 mm, the weight of concrete on top makes it almost impossible-even with

vibration-to get the air out from the bottom of the layer. In thin slabs compacted by a

vibrating beam, restrict the layers to 150-200 mm. With greater thickness, vibrators have to be

used. Place the concrete as quickly as possible but not faster than the compacting method and

equipment can cope with.

Where a good finish is required on columns and walls, fill the forms at a rate greater

than two metres height per hour. Also avoid delays and interruptions because these will cause

colour variations on the surface.

Make sure that each layer of concrete has been fully compacted before placing the

next one, and that each new layer is placed while the underlying layer is still responsive to

vibration. This will make the layers "knits" together.


Industrial Training Maga Engineering (pte)Ltd In columns and walls, the placing must be done in such a way that the concrete does

not strike the face of the formwork; similarly, avoid heavy impact against reinforcement, as

the force could displace it.

5.4.1 PLACING OF CONCRETE

The main objective in placing is to deposit the concrete as close as possible to its final

position as quickly and efficiently as you can, so that segregation is avoided and it can be

fully compacted.

Concrete can be transported by a variety of different methods ranging from

wheelbarrows, dumpers and ready-mix trucks to skips and pumps, and though it is obviously

desirable to place the concrete directly into position this is not always possible: for example, it

will seldom be practical to discharge from a dumper or ready-mix truck directly into the top

of a column or wall.

5.4.2 TRANSPORTATION OF CONCRETE

There are various methods are available for transporting concrete, ranging from

wheelbarrows to pumps, and many factors affect the choice:

o the nature of the site

o the ground conditions.

o the size of the job.

o the distance to be covered.

o the heights of loading and discharge.

On many jobs several different methods or a combination of methods may be required, for

example when concrete has to be transported both horizontally and vertically.

5.4.3 COMPACTION OF CONCRETE

After concrete has been mixed, transported and placed, it contains entrapped air in the

form or voids. The object of compaction is to get rid of as much as possible for this unwanted

entrapped air; down to less than 1% is usually the aim.

The amount of entrapped air is related to the workability: concrete with a 75 mm

slump contains about 5 % air, while concrete of 25 mm slump contains about 20 %. This is

why a low-slump concrete requires more compactive effort-either a longer time or more

vibrators compared with a concrete with a higher slump.



5.4.3.1 Reasons For Removing Air

Voids reduce the strength of the concrete. For every 1 % of entrapped air, the strength

falls by about 5 to 6 %. So a concrete with say, 3 % voids will be about 15-20 % weaker than

it should be.

Voids increase the permeability, which in turn reduces the durability. If the concrete is not

dense and impermeable, it will not be watertight, it will be less able to withstand mildly

aggressive liquids, and any exposed surfaces will weather badly; in addition, moisture and air

are more likely to get to reinforcement and cause it to rust.

Voids reduce the contact between the concrete and the reinforcement and other

embedded metals; the required bond will then not be achieved and the reinforced member will

not be as strong as it should be.

Voids produce honeycombing on stuck surfaces. Fully compacted concrete will be dense,

strong, durable and impermeable. Badly compacted concrete will be weak, non-durable,

honeycombed and porous. The air must be removed.

5.4.3.2 Vibration

By the vibration the entrapped air can be removed. When a concrete mix is vibrated it

is "fluidized", which reduces the internal friction between the aggregate particles. The

fluidization of concrete allows entrapped air to rise to the surface, and the concrete becomes

denser.

5.4.3.3 Vibrators

These are mobile items of mechanical plant used to vibrate (shake) air out of fresh

concrete.

There are 2 major types of vibrators:

o External vibrators (Form vibrators)

o Internal vibrators (Poker/Immersion vibrators)



Rules for using internal vibrators

1. Make sure you can see the concrete surface. Lights may be required in thin deep

sections.

2. Put the head in quickly. When inserting the poker, allow it to penetrate to the bottom

of the layer as quickly as possible under its own weight. If done slowly, the top part of

the layer will be compacted first, making it more difficult for the entrapped air in the

lower part of the layer to escape to the surface.

3. Insert the head vertically. This minimizes the voids created by inserting the head, and

allows air bubbles to rise up .

4. Do not stir. This only increases the voids.

5. Leave the poker in the concrete for about 10 seconds.

6. Withdraw the poker slowly. The main thing is to see that the hole made by the poker is

closed up; otherwise you will be left with a hole in the finished concrete. If this does

happen-and it is often difficult to prevent if the concrete is very stiff-put the poker

back in near enough to the hold for the next spell of vibration to close it up. For the

final insertion, withdraw the poker even more slowly and move it about to ensure that

the hole closes up properly.

5.4.3.4 Length Of Time Required For Full Compaction

1. As the concrete is vibrated, air bubbles come to the surface. When the bubbles stop it

can be taken as a sign that not much more useful work can be done on the concrete.

The distance of the bubbles from the poker is also a useful guide to its radius of action.

2. Sometimes the sound of the poker can be a helpful guide. When the poker is inserted

there is usually a dropping off in frequency, and when the pitch becomes constant the

concrete is free of entrapped air.

3. The surface appearance also gives an indication of whether or not compaction is

complete. A thin film of glistening mortar on the surface is a sign that the concrete is

compacted, as is cement paste showing at the junction of the concrete and formwork.



5.5 Curing

When water is added to cement chemical reaction takes place (Hydration of cement),

which results setting and hardening of cement. Mixing water is usually sufficient for the

initial hydration of cement. If however, there is insufficient water in the concrete during

its setting period, concrete can’t develop its full strength.

It is generally believed that the cement keeps on hardening for at least one

year. When concrete is laid, its water content is rapidly loss, if insufficient precautions are

not taken. This is due to evaporation occurs in the action of sun, wind and heat generated

during setting of cement. The prevention of such process is known as CURING.

But in sites normally curing will be done for 10 – 14 days. This is sufficient for

concrete to reach the required strength. It is found that concrete will get strength at an

increasing rate. The percentage increase of strength with respect to duration is listed

below,

Duration Percentage

3 days 40%

7 days 65%

28 days 100%

3 months 115%

6 months 120%

1 year 130%

Climate conditions and the type of cement used will also affect the curing practice.

Concrete will get more strength at high temperature and low at low temperature. Concrete

should be protected from harmful natural conditions. If proper curing is not taken place,

there will occur shrinkage initially and it leads crack.

There are two methods of curing is available. One is supplying moisture to

concrete and the other is preventing moisture from concrete. But in our site we normally

used the first method.



6.0 MASONRY WORK

Masonry is used to construct walls and foundation. Masonry walls may be partition

walls or load bearing walls.

6.1 MASONRY ITEMS

Masonry consists of two items;

(1) Bricks and blocks

(2) Mortar

6.1.1 BRICKS AND BLOCKS

6.1.1.1 Clay Bricks

They are made of firing clay or shale deposits. Normal size of brick 215×102×65mm

is called work size. The usual size of a brick is such that with one mortar joint to each face the

combination shall be 225×112×75mm.

Before it is used for construction it should be put into the water at least one hour. If they are

not put into water the bricks would absorb water from cement mixture and this would reduce

in hydration reaction in cement and reduce the strength of walls.

Figure : 6.1 Brick shape

Width of the brick is governed by the fact that it should be of such a size that a brick

can be easily geld by one hand. Height is governed by firing considerations during

burning.


Bed face

Stretcher faceHeader face

Height

WidthLength


6.1.1.2 Blocks

It is a walling unit exceeding in length, with or height the dimensions specified for a

brick. The height of a block work should not exceed either its length or six times its width,

to avoid confusion with slabs and panels.

In solid blocks small holes passing through or nearly through the block do not exceed

25% of its volume. In hollow blocks, holes passing through the unit exceed 25% of its

volume. In cellular blocks do not pass through entirely.

Types of blocks

Figure: 6.2 Types of blocks

In our site they have used hollow blocks for the construction of wall (Figure: 5.1). The

sizes that were found in our site are 390*190*200 mm and 390*190*100 mm. As the

strength of the wall increase with size of unit and since there are no practical difficulties in

making a bigger unit. Blocks are made as large as possible. Only restriction is that those

should not be heavier than about 25 kg to facilitate two handed laying.

6.1.2. MORTAR

Mortar generally mixed on volume basis with the help of a gauge box. The mix

proportion of the mortar may vary with the type of individual component whether brickwork


Front view

Plan view

Solid block Hollow block Cellular block

Industrial Training Maga Engineering (pte)Ltd or block work and with the thickness of the wall ( Table: 6.1 & Table: 6.2 ). In practice the

mixing can be done manually or using a tilting drum.

Type of mortar Cement Sand Location

Cement: sand mortar 1 8 Walls above ground level for

225mm thick wall

Cement :sand mortar 1 8 For walls of 115mm thick.

Table: 6.1 Mortar for brickwork

Type of mortar Cement Sand Location

Cement: sand mortar 1 8 Walls above ground level for 200

and 150mm thick walls

Cement: sand mortar 1 5 For walls of 100 mm thick.

Table: 6.2 Mortar for block work

6.2 BOND

6.2.1 NEEDS FOR PROPER BONDING

o To account for variations in brick dimensions so that verticality and horizontally of

a wall can maintained

o Provide uniform contact between adjacent bricks/blocks.

o Exclude rain and dust which may pass through the wall

o Make the brick wall a monolithic structural element

Accommodate different strains setup in different directions due to discrete walling units

which make the wall by a weak mortar which can undergo large strains with microcraking.



Figure : 6.3 stress distribution in a masonry wall.

Bond is the interlacement of bricks produced when they lap those immediately above or

below them. An unbounded wall with its continuous joints has little strength and stability

since load is not distributed evenly (Figure: 6.3). Strength of such a wall is also not

uniform and exceedingly weak at a continuously vertical joint.

6.2.2 SOME IMPORTANT TYPES OF BONDS

6.2.2.1 Stretching Bond

½ brick thick walls only = 113 mm only.

Figure : 6.4 Stretching bond


force

force

force

force

Plan of A

Plan of B

AB B

A

Industrial Training Maga Engineering (pte)Ltd 6.2.2.2 Heading Bond

1 brick walls only = 225 mm

Figure : 6.5 Heading bond

6.2.2.3 English Bond

For 1 brick,1 ½ bricks ,2 bricks …. thick walls.

This consists of alternate courses of headers and stretchers(Figure : 6.6).

Figure : 6.6 English bond


AB

Plan of A

Plan of B

BA

ABA

A

AB

Plan view of A

Plan view of B

Industrial Training Maga Engineering (pte)Ltd 6.2.2.4 Flemish Bond

This consists of alternate stretchers and headers in every course. This

considered to more attractive than English bond and is used to limited extent in

Srilanka(Figure : 6.7).

Figure : 6.7 Flemish bond

6.2.2.5 English Cross Bond

This differs from the English bond in the position of the stretcher in alternate courses. This is

also considered to be more attractive than English bond (Figure : 6.8).

`

Figure : 5.7 Flemish bond

Figure : 6.8 English cross bond


A

A

B

B

Plan view of A

Plan view of B

BA

Plan view of B

Plan view of C

Plan view of A

B

C

A

A

A

AC

B


6.3 WALL CONSTRUCTION

For the construction of wall we have to give more attention for the verticality and the

alignment of blocks.

In our site before start to construct the wall the lines were marked by the labourers who

are doing the setting out procedure. These lines were normally marked easily from the grid off

lines. By using a plumb bob those lines were transferred to the beam level (upper level) and

they tied a string between the top and the bottom markings by hammering nails.

By the above procedure or work the verticality of the wall can be easily maintained. This

is really reduce the work load that is on the masons. Because according to the string they can

easily built up the wall more quickly using a straight edge without any difficulty. Using a

plump bob for each and every block is really a time consuming work so by the above

procedure we can increase the speed of the work ( Figure : 6.9).

Figure : 6.9 Construction of wall


String

Gauge box

Industrial Training Maga Engineering (pte)Ltd 6.4 LintelThe lintel work means that a reinforcement beam kept between the block (or brick) work

where the opening will be provided.

The lintel is provided to take the bearing load affected by the overlaying block (or

brick) work. Generally it will be pre-casted at the site and then will place in the correct

position if the opening is small. Otherwise by using the shuttering work it will be casted. In

my site litel was casted by using shuttering works. The structural arrangement of lintel is

shown as follows,

Lintel

Opening

Figure: 6.10 Lintel arrangement

6.5 PROBLEMS AND THE EXPERIENCE ENCOUNTERED

1. Size of bricks and blocks are different. That was hard to construct the block or brick

wall with design thickness. When select the bricks must considered the sizes.

2. Before using any bricks or blocks for any construction work those should be soaked

into the water. Because if those are too dry they will absorb the water from the mortar

and then the water content of on the mortar will reduce and then we could not be able

to get proper bond between the blocks or bricks.

3. For constructing the wall vertically our site engineer suggested to tie a string between

the soffit and the floor ( Figure : 6.9 ). Because checking the plump line using a plump

bob for each and every block is really a time consuming procedure. To increase the

work speed the site engineer suggested that procedure. But some of the masons are not

quite happy with that. Because they do not like to change the procedure for their work.



7.0 PLASTERING

The function of plastering is protection of wall and the appearance of the building.

Various types of plasters are used. In our site cement plaster was used. Ratio of mixture of the

cement plaster is 1:5 cement, sand. Thickness of plastering is 15mm.

Plastering was the art of covering to surfaces with a plastic material to

obtain an even, smooth, regular, clean and durable surface.

The principle objects of plastering were,

To provide a true, even, smooth and finished surface to the work and improve the

appearance.

To protect the surfaces from harmful effects of atmospheric influences

To cover defective workmanship.

To cover up unsound and porous materials.

To give suitable ground for white wash, co lour wash, distemper or paint.

Plastering conceals defective workmanship and covers up unsound and cheap quality

material. Often, plastering was required to provide a satisfactory base for decorating the

surface by whitewashing, color washing, distempering or painting. External plastering also

termed as ‘’ rendering ‘’ was done with the object of improving the resistance of the surface

to rain water penetration and other atmospheric influences.

The following factors affected the selection of the type of plaster to be used:

1. Availability of binding materials.

2. Desired durability and finish.

3. Atmospheric conditions to which the plaster would subjected.

4. The place where the plaster is going to be used lime whether on exterior surfaces or interior

surfaces.

The plastic material or plaster was made by working together a mixture of building material,

which was cement, lime or clay, fine aggregates (usually sand) and water. Certain additives

were sometimes added to improve its adhesiveness, durability and luster. When cement was

used as the binding material, the plaster was termed as cement plaster and when lime was

used as the binding material, it was called lime plaster. Sand normally forms the greatest

proportion of the constituents of a plaster. Sand controls the shrinkage, porosity, strength and

adhesive properties of plaster. Fine sand was often recommended for plastering and it should

be so graded that it has not pass by more than 5% through a sieve of 100 mesh ( b.s. sieve ).

Used sand were clean, sharp and free from deleterious matter. Normal tap water was used to


Industrial Training Maga Engineering (pte)Ltd add. Depending upon the availability of the materials, the choice of plaster for any particular

location, was governed by the rainfall, weather conditions and the finish desired.

7.1 LIME SLURRY

Using slaked line and water to a consistency of slurry by mixing in a tub or a

bucket makes lime slurry. This slurry is used for obtaining a smooth finish for internal walls.

It is done by letting this slurry flow over the plastered surfaces ( commonly referred to as

floating ) and then making a smooth finish by toweling with wooden float. As with the case

with lime it takes time for hardening and adequate care is not taken this finish is bound to get

damage.

PROBLEMS AND THE EXPERIENCE ENCOUNTERED

1. Before plastering wall has to curing by the water. Because avoid present voids

between wall surface and motor. But our site they did not consider about that.

2. In corridor walls, plaster tags have to put together. Otherwise after finishing work

sometimes walls were not same line. That is not good appearance. But our site several

times they did not consider about that.



8.0 TILING

Tiling is generally done to get a nice appearance to the internal part of a building. Tiling

work can be divided into mainly three types. There are wall tiling, floor tiling, and staircase

tiling. They are available in different sizes. For our site tiles were brought from “Lanka wall

tiles and Royal ceramic”. During in our training period they were doing only wall tiles work.

8.1 WALL TILES

Wall tiles are usually done on to the bath room walls. The process of wall

tile is given below,

For placing the wall tiles the procedure is given below,

. Setting out was done on the cleaned surface.

. All tiles were placed in a water bucket for some time (15- 20 minutes) before placing the

tile.

. Then cement mortar was applied to the surface. Tiles were aligned properly.

. After that cement grout was applied to the tile according to the tile colour.

Wall tiles sizes

Length = 152mm

Wide = 152mm

Thickness = 6mm

8.2 TILE CUTTING

While tiling sometime we need required sizes. Therefore we have to cut the tiles

to achieve the suitable size. For this purpose special type of cutting tools are available in use,

for example,

1. Scaiber _ widely used for linear cutting.

2. Wheel cutter _ mainly used for wall tile for line cutting.



9.0 ABOUT THE ROAD PROJECT ORGANIZATION

GODAGAMA TO MALABE ROAD PROJECT

9.1 ABOUT THE STE DETAILS

LOCATION Malambe to Godagama Road Project.

CLIENT Road Development Authority.

CONSULTANTRoughton International (U.K),Engineering Consultants Ltd (Sri Lanka),Asphalting (Pvt) Ltd (Sri Lanka).

CONTRACTOR Tudawe Brothers Ltd.

COMMENCEMENT 01 – 02 – 2002

COMPLETION 30 – 04 - 2004

PROJECT COST Rs. 370 million.

FUNDED Asian Development Bank (A.D.B).

ROAD LENGTH 11.3 km

Table : 9.1 About road site details



9.2 SITE ORGANIZATION CHART

Figure : 9.1 Structure of the organization for road site.


PROJECT MANAGER

Quality control

Laboratory Assistant

Lab Technician

Project Quantity Surveyor

Quantity Surveyor

Site Manager

Surveyor

Assistant Surveyor

Project Engineer

Assistant Engineer

Work shop ForemenTechnical Officer Draught person

Trainees Supervisor

Assist store Keeper

Accountant

StoreKeeper


10.0 HIGHWAY CONSTRUCTION

A highway is a hard surface made on an embankment for easy transport of

goods and passengers by vehicles. Usually a highway connects two stations. In addition to

connect two stations it will have serve a lot of people around the road.

10.1 A GOOD HIGHWAY SHOULD HAVE THE FOLLOWING QUALITIES.

1. It should be straight as much as possible.

2. It should be short as much as possible

3. It should have easy curves

4. It should have low gradients

5. It should have strong foundations

6. It should have good sight distance.

10.2 HIGHWAY CONSTRUCTION CATOGARIES Construction of highway is divided into three categories

a. New constructions

b. Re-constructions

c. Stage-constructions

10.2.1 NEW CONSTRUCTIONThis is meaning that the highway is constructing from initial stage to connect two

stations.

10.2.2 RE-CONSTRUCTIONSAny improvements or constructions works done in already made highway are called re-

constructions.



10.2.3 STAGE CONSTRUCTIONS The construction works are carried out in stages.

Ex:

Stage1 -Constructing structures such as stage drain, culverts, bridges and retaining

Walls

Stage2 - Preparing sub base

Stage3 - Metaling and taring.

10.3 ALIGNMENT Marking the position of the highway on the ground is known as alignment.

Alignment or locations of the highway comprises of the following two components,

1.Horizontal components:

It includes the straight path, curves and horizontal deviations

2.Vertical components:

It includes verticals curves, verticals gradients and etc.

Both these components play a vital role in determining the alignment of a road.

After careful study of the area. Except in flat areas due consideration has to be given to the

grade as it will be difficult to use a road having very high grades. Once the road is aligned and

constructed. It becomes it, due to high cost of construction and increases in value of ad joints

land.

10.4 FACTORS THAT AFFECTED THE LOCATION OF NEW HIGHWAY

1 Shortest length

2 Low gradient

3 Easy curves

4 Good sight distance

5 Adequate drainage

6 Least earth work

7 Easy river crossing and railway crossing

8. Material requirement


Industrial Training Maga Engineering (pte)Ltd 11.0 ENGINEERING SURVEYES FOR HIGHWAY LOCATION

In a highway project, before finalizing the alignment of a highway or road engineering

surveys are to be carried out, the surveys may be completed in the following four stages,

1 Map study.

2 Reconnaissance surveys.

3 Preliminary surveys

4 Detail surveys.

11.1 MAP STUDY

If the topographic map of the area is available, it is easy locate the likely

routes of the road. If the map is not available the area photographs will be taken for this

purpose. On these maps main features of the area like rivers, hills etc. after studying these

maps in the office carefully the probable alignment can be located on the map keeping

following points in view.

a. Alignment should avoid ponds, lakes, valleys, inhabited area etc.

b. In case of a hill road, it should pass through a mountain pass.

c. For crossing a river, curved path should be avoided. The road should cross the

river at right angle.

11.2 RECONNAISSANCE SURVEYS

It is quick and without instruments survey. In this survey only

very simple instrument like abbeys level, tangent clinometers and barometer etc may be used.

Some of the details to be collected during reconnaissance are,

I.Terminal points and approximate length of the proposed road

II. Traffic conditions and design standards such as gradient, radius of the curves etc.

III.Drainage facilities provided such as number and type of cross drainage structures,

natural flood level and natural ground water level along the suggested route.

IV.General characteristic of the area such as type of soil, observation of geological

features, valleys, ponds, rivers, hills, permanent structures, marshy land.

V.Availability of construction materials

VI.Transport facilities available.


Industrial Training Maga Engineering (pte)Ltd VII. Approximate cost per km of the route

11.3 PRELIMINARY SURVEYS It is approximate or rough type of survey conducted to have

fair idea of the surrounding areas. This type of survey generally is done with the help of a

plane table, compass, chain or steel tape. To have idea of earthwork approximate levels are

also taken at different points.

11.3.1 THE MAIN OBJECTIVES OF THE PRELIMINARY SURVEYS AS FOLLOWS

To survey the different alternative alignment proposed for the highway on the basis

of reconnaissance survey and to collect all necessary details of topography,

drainage and soil etc.

To compare the merits and demerits of different proposed alignment.

To estimate the quality of the different alternative proposals.

To workout cost of the different alternative proposals.

To select and finalize the best alignment from all considerations.

11.3.2 LOCATION AND DETAILED SURVEY The alignment finalized on the basis of preliminary surveys is

to be located on the ground by establishing centre line by driving pegs at 20 m intervals. After

this operation the detailed survey is carried out for collecting information for the following

works.

Design of the highway

Preparation of construction plans.

Estimate earthwork.

Work out of the cost project.

11.4 DETAIL SURVEYS To carry out levelling survey, temporary benchmarks are generally

fixed at intervals of about 300 meters. The cross section levels are taken up to the desired

width at intervals of 10 meters or at closer intervals where slopes change abruptly.

All river crossings, valleys etc are surveyed in detail up to considerable distance on either

side. All-important topographical features should be noted in detail and plotted.


Industrial Training Maga Engineering (pte)Ltd Information regarding existing hydraulic structures such as culverts, bridges should be

gathered.

12.0 ROAD CONSTRUCTION MATERIALS

12.1 INTRODUCTION ABOUT THE MATERIALS

In this project is also included with road network improvement Project. There are several layers are laid. About that layers are given below the table.

Layer Thickness TypeSurfacing C/W 50 A/C Shoulder 20 SBSTMinimum Overlay 150 GBBase Course 200 GBSub Base 250 GSS.S.G 130 GC Table : 12.1 Introduction about the materials

SBST - Single Bitumen Surface TreatmentGB - Granular Base course GS - Natural Gravel or Similar ApprovedGC - Gravel Soil or Similar approvedS.S.G - Selected Sub GradeC/W - Carriage WayA/C - Asphaltic Concrete

12.1.1CROSS SECTION OF THE ROADCarriage way : 3.7 mShoulder : 1.8 m

Carriage way

Shoulder

3%

Invert level


1.8

0.3

5.5

3.7

3%

6.7

0.6


Figure :12.1 Cross section

12.2 ROAD CONSTRUCTION OPERATIONS

1. Clearing & Grubbing

2. Road way excavation in the all classes other than rock requiring blasting and part

refill

3. Rock excavation

4. Type П material fill

5. Sub base construction type І material

6. Aggregate Base Course

7. Tack coat

8. Prime coat

9. Asphalt concrete surfacing

In our training period we have seen only Sub base construction,

Aggregate Base Course, Prime coat and Asphalt concrete surface works.

12.3 SUB GRADE

The material shall be suitable material obtained either from excavation cut or from

approved borrow areas. No aggregate in the materials shall be greater than two thirds of the

layer to be compacted.

Degree of compaction: Top 150mm should be more than 95% MDD

Lower layers should be more than 93% MDD.

The rate of compaction test for every 500 sqm.

MDD is indicated “Maximum Dry Density”.

12.3.1 SELECTED SUB GRADE


Industrial Training Maga Engineering (pte)Ltd Materials used for selected sub grade shall be naturally occurring soils or gravels

and shall not include highly plastic clays, silts, peat or other organic soils or any soil that is

contaminated with topsoil, vegetable or other deleterious matter.

SL properties No. Test method

AASHTO

Selected sub grade

Liquid Limit not to exceed T90 40

Plasticity Index not to

Exceed

T90 15

Maximum dry density

Not less than (kg/m3)

T180/BS1377 test 14 1650

4 days soaked CBR at 93%

MDD not less than (%)

T193 15

Table : 12.2 Requirements of sub grade materials

12.3.2 FAILURE OF SUB GRADE

The failure of sub grade may be attributed due to the following two causes.

Inadequate stability

Excessive stress application

The inadequate stability of the sub grade may be attributed due to the following factors,

Inherent weakness of the soil itself.

Excessive moisture in the sub grade.

Inadequate compaction of the sub grade.

12.4SUB BASE

The materials used for sub base shall be naturally occurring or blended gravels and sands

or mixtures there have and shall not include highly plastic clays, peat or other organic soils or

any soil that is contaminated with top soil vegetable and other deleterious matter.

The completed sub base shall contain no aggregate.

Degree of compaction > 98% of MDD.




SL properties No.Test method

AASHTO Sub base

Liquid Limit not to exceed

(%)T90 40

Plasticity Index not to

exceed(%) T90 12

Maximum Dry Density not

Less than (kg/m3)T180/BS1377 Test 14 1750

4 days soaked CBR at 98%

MDD not less than (%)T193 30

Table : 12.3 Requirements of sub base materials.

Grading Requirements for Sub Base Materials

Sieve size (mm) % Passing

50 100

37.5 80-100

20 60-100

5 30-100

1.18 17-75

0.3 9-50

0.075 5-25

Table :12.4 Grading requirements for sub base materials

12.4.1 FAILURE OF SUB BASE

Failure of sub base takes due to the following reasons,

Inadequate strength or stability

Loss of cohesion or binding action

Loss of materials

Inadequate thickness of wearing course


Industrial Training Maga Engineering (pte)Ltd Use of improper or inferior materials

Crushing of base course

Lack of lateral support for the base course

Following are the main reasons for the inadequate strength or stability of the sub base

Improper mix proportion

Inadequate thickness of the sub base

Use of soft variety of stone aggregates

Poor quality control during construction period

12.5 AGGREGATE BASE COURSE (ABC)

After the edge treatment the base materials shall be laid for the road.

Aggregate Base Course is a mixture of various sizes of aggregates and quarry dust in it.

Normally aggregates of 37.5mm, 28mm, and 20mm… are included.

In this project the thickness of the ABC layer is 200mm. The motor

grader is used to laying ABC. Normally the road has a cross fall of 3% from the center the

motor grader can be used to blade the road as required.

After placing it shall be compacted well using the rollers and the compaction shall be

tested.

Degree of compaction > 98% of MDD.


12.5.1 COURSE AND FINE AGGREGATE

Course aggregate substantially retained on the 4.75mm sieve and

fine aggregate substantially passing 4.75mm sieve.

The course aggregate shall be crushed rock from an approved

quarry and the fine aggregate shall either be crusher fines or river sand.

They shall be free from weathered, soft, laminated or elongated

pieces, deleterious matter and shall be free from clay and excess dust.


Industrial Training Maga Engineering (pte)Ltd For course aggregate used for asphalt concrete surfacing and seal

coat surface treatment shall have a lost angles abrasion value not greater than 40%.

Fine aggregate used for road bases and surfacing shall either be

crusher fines or river sand.

12.5.2 METHOD OF SELECTING MATERIALAggregate Base Course material shall be selected according to the

following requirements.

Grading Requirements for ABC Materials

Sieve SizePercentage PassingNominal Size (mm)

37.5 28.0 20.050.0 100 100 -37.5 95-100 100 -28.0 - - 10020.0 60-80 70-85 90-10010.0 40-60 50-85 60-755.0 25-40 35-55 40-602.36 15-30 25-40 30-450.425 7-19 12-24 13-270.075 5-12 5-12 5-12

Table : 12.5 Grading requirements for ABC materials

12.6 PRIME COAT

This work shall consist of an application of a prime coat on a base or sub base

newly constructed using gravely soil, stabilized soil or aggregate prior to laying of a surface

dressing or a surface course, so as to provide a proper bond between the layers and also to

serve as a protective measure for the base or sub base.

12.6.1 PREPARATION OF SURFACE

The layer to be primed should be cleaned of all loose and deleterious material by means

of a rotary broom or hand brooms. The brushing force should be sufficient to dislodge all

adhering material without damaging the pavement surface. Clay and other foreign material

should be removed by hand. The exposed surface should be kept moist up to the time of

spraying.Department of Civil Engineering 102




12.6.2 APPLICATION OF PRIME COAT

Prime Coat should be applied at the instructed rate after trials and temperature

defined in (Table : 12.6) by means of a bitumen distributor for large areas and by hand lance

and nozzles for small and inaccessible area so as to achieve an even distribution of the prime

coat over the surface. At the start and end of each run building paver or other approved

material shall be spread over the surface to ensure a clean joint between adjacent runs and to

protect adjacent surface and also to permit the distributor to build up sufficient speed so that

at the start of each run the distributor shall be travelling at the correct speed for the instructed

application rate. There should be no leakage or drips of oil, diesel or bituminous material from

the distributor.

The total width of primed surface should be 300mm wider than the specified

width of the final surfacing and the edges of the prime shall be parallel to the centre line of the

road.

The indicative rate of spread of bituminous material for the prime coat should be in

the range of 0.5 to 1.5 litters per square meter.

Prime Coat Type Temperature (Degree Celsius)

MC 30 or 45% Cut back bitumen 40 – 70

MC 70 or 35% Cut back bitumen 55 – 90

MC 250 or 25% Cut back bitumen 75 - 110

Table : 12.6 Relationship between prime coat and temperature

Sieve Size Percentage Passing (By mass)

4.75 100

2.36 80 – 100

1.18 60 – 95

0.6 30 – 80

0.3 20 – 55

0.075 10 – 30

Table : 12.7 Grading Envelope for Sand for Prime Coat


Industrial Training Maga Engineering (pte)Ltd 12.7 TACK COAT

This work shall consist of an application of a tack coat to an existing pavement

prior to construction of a surfacing, so as to provide a bond between the two layers.

Penetration grade bitumen:

The penetration grade bitumen used for road construction and refining petroleum

shall derive maintenance work.

12.8 ASPHALTIC CONCRETE SURFACING

This work shall consist if furnishing materials, mixing at a central mixing

plant, and spreading and compacting asphaltic concrete wearing course on an approved base

course as and where shown on the drawings and as instructed by the Engineer. The wearing

course will be typically of 50 mm thickness as specified.

12.8.1 PREPARATION OF EXISTING SURFACE

Where asphaltic concrete surfacings are laid over newly constructed

aggregate bases, prior to construction, the surface shall be cleaned of extraneous matter and

applied with a prime coat. Where asphaltic concrete surfacings are laid on existing

pavements, the surfaces of such pavement shall be corrected to the required width and profile

as instructed. All potholes, ruts, depressions, and damaged edges shall be corrected.

12.8.2 WEATHER LIMITATIONS The bituminous mix shall not be laid during rainy weather or when the

surface on which it is laid is damp or wet.

12.8.3 ASPHALT LAYING PROCEDURE

The Asphalt mix shall be laid immediately after transporting, by means of

approved mechanical self powered pavers. They shall be capable of spreading, finishing and

providing initial compaction to the mix so that, the surfacing can be finished to the required

lines, grades, levels, dimensions, and cross sections intended, either over the entire width or

over such other partial widths as may be practicable.


Industrial Training Maga Engineering (pte)Ltd The bituminous mix, after spreading, finishing, and initial compaction by the

paver, shall have a smooth surface free of irregularities causes by dragging, tearing or

gouging.

In narrow widths and in restricted areas where the paver cannot operate, the mix

may be manually laid. In which case, care shall be taken avoid segregation. Manually laid

strips shall be rolled at the same time as the paver laid work.

12.8.4 COMPACTION PROCEDURE

Immediately after the mix has been spread as struck off, the

surface shall be checked and any irregularities adjusted. Rolling shall commence as soon as

the material will support the roller without undue displacement or cracking. The mix shall

then be thoroughly and uniformly compacted by rolling, according to the sequence of rolling

as given below,

1. Transverse joints.

2. Longitudinal joints, where applicable.

3. Outside edge.

4. Initial or breakdown rolling.

5. Second or intermediate rolling.

6. Finish or final rolling.

The speed of the roller, shall not exceed the limits given below the table.

Type of Rollers Breakdown

speed (km/hr)

Intermediate speed

(km/hr)

Finish speed

(km/hr)

Steel Wheeled Rollers 3 5 5

Pnumatic Tyred Rollers 5 5 8

Vibratory Rollers 5 5 -

Table : 12.8 Relationship between rollers and their speed



13.0 SPECIAL EQUIPMENTS

13.1 PNEUMATIC TIRED ROLLER

The pneumatic tired roller is recommending to be used on asphalt surface treatment.

The resilient tyres on these rollers force the aggregate firmly into the asphalt binder without

crushing the particles. It is also widely used on asphalt pre- mix paving in combination with

tandem steel rollers. The most popular type of pneumatic-tyred roller for road maintenance is

the self propelled smooth –tread tyred roller with 3 or 4 wheels at front and, 4 or 5 wheels at

rear.

The front wheels are always mounted on oscillation axles and on some models are the front

suspension constructed with hydraulic pressure equalisation which provides a “kneading

action” allowing the wheels to follow the contour of the surface and provide better

embodiment. The front and rear wheel sets are installed in a “staggered” position providing an

overlap in the gaps between the wheels.

The water sprinkler system for tyres and tyre scraper’s are normally included. Most models

are provided with a tyre inflation system, either a hose for manual operation or with automatic

tyre inflation, adjustable from the driver’s seat. Enabling the driver to increase or decrease the

tyre pressure during operation.

13.2 BACKHOE

This type of machine is the one that is most commonly used machine by the

contractors for excavating basements, pits and trenches. This is also called the “backhoe”.

Discharge is by raising the bucket in a tucked position and emptying the spoil through the

open front end into the attendant haul unit or alongside the trench. Output varies from 60

bucket loads per hour, and this depends on the nature of the excavation area.

13.3 FACE SHOVEL

This excavator operates best from a flat prepared surface to work above the tracks against an

excavation face. It serves only to loosen and load material and is mostly used in quarrying and

road cuttings. In our site they used for spreading sub base and ABC and move that materials

from one place to another place.



13.4 MOTOR GRADER

Many earthmoving projects require the final ground to be accurately finished. So that the

surface is smooth and level without undulations and ridges. Although a skilful driver using a

bulldozer can in many instances achieve adequate results, the grader has been specifically

developed for trimming the sub grade, sub base, ABC surface on the roads and road cuttings.

It is self transporting and supported on two or three axles.

Methods of working with the Grader

The blade can be used in several positions for:

Levelling and trimming on the horizontal, with the mould board central or swung out

either to the left or right. If the mould board is set at an angle on plan, the material will

roll off the blade to form a windrow. However, with the blade at right angles to the

line of movement, then only spreading or trimming is obtained.

Levelling and trimming to the slope and vertical face.

Forming ditches the mould board is angled both on plan and in the vertical and set

such that the blade just protrudes beyond the outside line of the wheels nearest to the

ditch to be shaped. A windrow is formed along the top of the ditch. The ditch is

depended gradually, trimming off a layer at a time, keeping the nearside wheels in the

ditch.

Back filling along trenches. The action is similar to that for producing a windrow.

13.5ASPHALT PAVER FINISHER

A paver finisher is a machine for laying asphalt for road construction to

give accurate depth, even levelling and good surface finish before rolling.

We can use Paver for sub base or ABC work. But our site they have not used. But it is

compared to the motor grader method, is found more suitable, because,

1. Better and easier respect of levels, both longitudinal and transvers.

2 . Improved homogeneity of the plant prepared mix.

3. Uniform pre-compaction.

4. Improved adherence of asphaltic courses.



The paver can easily handle asphalt and all asphalt mixes, coated and uncoated materials,

crushed stones and dry lean concrete, in fact all road making materials other than wet

concrete.

This is the equipment used for paving road surface with asphalt. The paver should

be capable of spreading finishing and providing initial compaction of the asphalt mix. It

should be able spread the mix to correct lines, grades levels, dimensions and cross section

intended, either over the entire width or part of widths as case may be.



14.0 SPECIAL TESTS

14.1 ATTERBURG LIMITS DETERMINATION

This test consists of two parts.

1. Liquid Limit determination

2. Plasticity Limit determination

14.1.1 LIQUID LIMIT DETERMINATION

From the selected material a sample about 100g, which passes through 0.425mm

sieve was taken.

The sample was mixed with distilled water on the glass plate.

A portion of the mixture was placed in the cup and levelled with the use of the

spatula.

With the use of the grooving tool the levelled mixture was divided along the

diameter through the center of the hinge.

By rotating the handle of the machines number of blows were be given until the

two parts comes in to contact.

A small quantity of the mixture was removed by the grooving tool was placed in a

container and weighted.

After that it was be dried in the oven and weighted.

Then moisture content was calculated as shown in the attached test report.

Above test shall be carried out for four samples. (For two samples no. of blows <

25, for the other two samples blows >25)

Liquid Limit is the moisture content corresponding to the water contest of 25

blows.

14.1.2 PLASTICITY LIMIT DETERMINATION

Selected material sample was mixed with distilled water on the glass plate until it can

be rolled and it shall be rolled between the hand and the glass plate.

When it comes to a thread with a diameter less than 3mm the soil shall be kneaded

together and was rolled again. This should be done until the thread shows signs of

cracks and further could not be rolled.

The cracked threads were put in to a container and weighted.


Industrial Training Maga Engineering (pte)Ltd Then it was be dried in the oven and weighted.

Test was being carried out for two samples and moisture content can be determined.

The average moisture content of the two samples is the plastic limit.

From the results of the above two tests plasticity index can be acquired.

Plasticity Index = L.L – P.L

14.2 SIEVE ANALYSIS TEST

Sieve analysis test is important when grading the materials. First sample of dry selected material was weighted.

The set of sieves was selected.

Take the sample and pass through the sieves (Starting from the largest

one)

Soil remained at each sieve was weighted and therefore passing

percentage can be calculated.

Sieve analysis test is done for concrete aggregates, ABC material and

asphalt material as well as for soil.

14.3 PROCTOR COMPACTION TEST

In this test, a sample of soil is compacted in a standard container (volume

of the mould is 996 cm3). The container is filled in five layers. Each soil layer is compacted

using a 4.5kg weight, which is lifted through a distance of 450mm and dropped 27 times

evenly over each soil layer.

After striking off the surface of the container, the soil sample is weighted

immediately after the test (wet weight) and then weighted again after drying the soil in an

oven (dry weight). The difference between the wet and dry weights represents the weight of

water that was contained in the soil. The density of the dry soil can now expressed in terms of

kg per cubic meter. The amount of water or moisture may also be expressed as a percentage

of the dry weight.

The procedure is repeated, adding different amounts of water to the soil with each

repetition and the soil weights as well as percentages of moisture are recorded as described

previously.



Plotting the data on a graph, a curve similar to following graph,

Dry Density Maximum Dry Density

Optimum Moisture Content

Moisture content (%)

Figure : 14.1 Dry Density Vs Moisture Content

From this curve we can find Maximum Dry Density & Optimum Moisture Content.

14.4 FIELD DENSITY TEST BY SAND CONE METHOD

After the compaction of each layer the density achieved in the

field should be determined. In the site sand cone method can be done to determine the

density of the compacted fill material.

In the sand cone method small holes are made at several places in the compacted

layer. The weight of the soil removed can be measured. The volume of the hole can be

obtained by filling the hole with sand (density of the sand is known). Then the density of

the soil can be calculated.

The standard proctor compaction density value can be compared with the field

density. Field compaction density is usually specified to be above 98% of the standard

proctor compaction test in the laboratory for sub base and ABC materials layers. If not

further compaction is necessary.



Calculation for Degree of Compaction

Volume of the hole = Weight of sand in the hole Density of the sand used Wet density of the soil = Wet soil in the excavation hole Volume of the hole

Dry Density of the excavated soil = Wet Density * 100 (Moisture content of the soil + 100)

Degree of Compaction = Dry Density of the Excavated soil *100 Lab Maximum Dry Density



15.0 PROBLEMS AND THE EXPERIENCE ENCOUNTERED

1. Over compaction is not good for the sub base or any other layer. Because if we over compact to the soil, shear failure will be presented. But they did not consider about over compaction.

2. Before priming surface has to clean. After cleaning immediately prime coat will be

primed. But our site sometimes after cleaning one or two days they will prime.

3. After priming within 24 hours without being disturbed. So as to allow the prime coat

to fully penetrate the surface unless full penetration. But they did not consider about

that.



16.0 SAFETY

Unaccepted accident causes pain, permanent disabilities, human suffering or

death. This affects the victim and other working resulting in loss of morale and even a fear of

performing certain tasks. Therefore accident in construction competent, safety–conscious,

supervision, education, discipline, job safety organization, safety device and equipment.

16.1 SAFETY PROCEDURES

All persons must wear safety helmets before enter the site works.

Do not though any heavy things on high level that may cause injuries.

Ensure that there is no danger from live electrical cables or equipment near to work is

carried out.

Goggles and screens must be used when doing the work that might cause damage to

eyes.

Always wear a suitable when doing work that creates dust.

As the nature of the work boots and gallowses must be use.

Keep work area clean

Consider area environment

Power tools were not exposed to rain. They were not used in damp or wet location.

Machineries were not use if there is risk to cause fire or explosion.

Guard against electrical socket

Do not let visitors touch the tools or extension chord.

Store ideal tools

Do not force tools (it will do the job better and safer at rate for which it was intended)

Use right tools

Dress properly

Use safety glasses; also use face or dusk mask if cutting operating is dusty.



17.0 CONCLUSION

After finishing the Level 3 examination we have to go into the industry as civil

engineers. Without knowing about the industry and practical knowledge we could not be able

to survive as real engineers in future. By considering this University of Moratuwa and NAITA

decided to have an Industrial Training programme for undergraduates after finishing their

Level 3 examination.

While we are in the university we are studying many theories. Even though we are

doing a lot of practicals during the academic year to understand the concepts clearly, certain

things can not be found or can not be learnt as concepts such as labourer management.

Therefore it is necessary to take the Industrial Training as serious and we have to do it

properly. Labourer management is very important for civil engineers because most of the time

they have to deal with the labourers directly or through subcontractors.

Civil engineer should have the ability to coordinate the other labourers or subcontractors to

finish a construction within the limited valuable time period. They must have the ability to

work as a team otherwise they could not meet the target within the allocated time. There may

be conflicts between the different subcontractors about the construction work those should be

solved by engineers to finish the construction within the limited period. These things can be

easily learnt from the industrial training period.

Twenty-two weeks were allocated for our Industrial Training programme. Within that

duration learning everything about the construction was not possible. Because of this reason a

trainee might got the chance only to learn a part of the construction. Normally one particular

work is repeated even for several months .Hence just increase the training period will not be

the solution for the above problem. Therefore it is better if the trainees can be changed

themselves to the other sites of the same organization where other part of the construction is

going on with the aid of the University and NAITA.

The Department of Civil Engineering from University of Moratuwa allocated a staff member

for each and every student during the training period. Therefore the trainee gets supervised by

that staff member every month and he/she has the chance to speak about their problems

related to their training programme with the staff member.


Industrial Training Maga Engineering (pte)Ltd This type of supervision really motivated us to finish the training successfully.

I feel sad to say ,that in our site mainly road site, most of the staffs were not really

worried about the trainees whether the trainees have got or learnt anything from their training

period. They only aimed on the work that we were done for them and they only wanted to

finish those work in time. In our sites they have not any special programme for trainees we

have to work as a technical officer or sometimes even as a labourer. If the organisation have a

defined programme for trainees, that really will guide the trainees in their learning procedure.

During our training period we were work with several trainees from other institutions.

Their training period is more than two years. But our training period is only twenty-two

weeks. Therefore we have to learn everything within twenty-two weeks. Therefore we have to

work hard in our training period. Otherwise they will defeat us.

Finally I wish to thank the whole staff of University of Moratuwa and

to the staff of NAITA.


CONTENTS

1.0 INTRODUCTION..............................................................................................................1

1.1 ABOUT THE ORGANIZATION..................................................................................59

1.2 ON GOING PROJECTS................................................................................................59

2.0 ABOUT THE LSP (BUILDING SITE) ORGANIZATION.............................................60

2.1 ABOUT THE SITE DETAILS......................................................................................60

2.2 THE ORGANIZATION CHART..................................................................................61

2.3 JOB FUNCTIONS....................................................................................................63

3.0 FORM WORK..................................................................................................................66

3.1 REQUIREMENTS FOR FORMWORK..................................................................66

3.2 TIME OF REMOVAL..............................................................................................66

3.2.1 The minimum period to removing formwork..........................................................67

3.3 FORM WORK FOR BEAMS AND SLAB..............................................................68

4.0 REINFORCEMENT.........................................................................................................69

4.1 INDICATION OF REINFORCEMENT IN DRAWING.............................................69

4.2 COVER BLOCKS........................................................................................................70

4.3 BAR BENDING WORK..............................................................................................70

4.4 PLACING OF REINFORCEMENT.............................................................................70

5.0 CONCRETE......................................................................................................................71

5.1 GRADE OF CONCRETE..............................................................................................71

5.2 CHECKS BEFORE CONCRETING.............................................................................72

5.3 TEST FOR CONCRTE..................................................................................................73

5.3.1 SLUMP TEST..........................................................................................................73

5.3.2 CUBE TEST............................................................................................................74

5.4 CONCRETING..............................................................................................................75

5.4.1 PLACING OF CONCRETE....................................................................................76

5.4.2 TRANSPORTATION OF CONCRETE.................................................................76

5.4.3 COMPACTION OF CONCRETE....................................................................76

5.5 Curing.............................................................................................................................79

6.0 MASONRY WORK..........................................................................................................80

6.1 MASONRY ITEMS.................................................................................................80

6.1.1 BRICKS AND BLOCKS..................................................................................80

II

6.1.2. MORTAR.........................................................................................................81

6.2 BOND.............................................................................................................................82

6.2.1 NEEDS FOR PROPER BONDING........................................................................82

6.2.2 SOME IMPORTANT TYPES OF BONDS.....................................................83

6.3 WALL CONSTRUCTION.......................................................................................86

6.4 Lintel............................................................................................................................87

6.5 PROBLEMS AND THE EXPERIENCE ENCOUNTERED........................................87

7.0 PLASTERING....................................................................................................................88

7.1 LIME SLURRY..............................................................................................................89

7.2 PROBLEMS AND THE EXPERIENCE ENCOUNTERED...................................89

8.0 TILING...............................................................................................................................90

8.1 WALL TILES.................................................................................................................90

8.2 TILE CUTTING.......................................................................................................90

9.0 ABOUT THE ROAD PROJECT ORGANIZATION.......................................................91

9.1 ABOUT THE STE DETAILS.......................................................................................91

9.2 SITE ORGANIZATION CHART.................................................................................92

10.0 HIGHWAY CONSTRUCTION.....................................................................................93

10.1 A GOOD HIGHWAY SHOULD HAVE THE FOLLOWING QUALITIES..........93

10.2 HIGHWAY CONSTRUCTION CATOGARIES........................................................93

10.2.1 New construction...................................................................................................93

10.2.2 Re-constructions....................................................................................................93

10.2.3 Stage constructions................................................................................................94

10.3 ALIGNMENT...............................................................................................................94

10.4 FACTORS THAT AFFECTED THE LOCATION OF NEW HIGHWAY..............94

11.0 ENGINEERING SURVEYES FOR HIGHWAY LOCATION.....................................95

11.1 MAP STUDY............................................................................................................95

11.2 RECONNAISSANCE SURVEYS...........................................................................95

11.3 PRELIMINARY SURVEYS.......................................................................................96

11.3.1 The main objectives of the preliminary surveys as follows...................................96

11.3.2 Location and detailed survey.................................................................................96

11.4 DETAIL SURVEYS....................................................................................................96

12.0 ROAD CONSTRUCTION MATERIALS......................................................................97

12.1 INTRODUCTION ABOUT THE MATERIALS........................................................97

12.1.1Cross Section of the road........................................................................................97

12.2 ROAD CONSTRUCTION OPERATIONS.............................................................98

12.3 SUB GRADE............................................................................................................98III

12.3.1 SELECTED SUB GRADE....................................................................................98

12.3.2 FAILURE OF SUB GRADE.................................................................................99

12.4 SUB BASE................................................................................................................99

12.4.1 FAILURE OF SUB BASE..................................................................................100

12.5 AGGREGATE BASE COURSE (ABC)..................................................................101

12.5.1 Course and fine aggregate....................................................................................101

12.5.2 Method of Selecting Material............................................................................102

12.6 PRIME COAT........................................................................................................102

12.6.1 Preparation of Surface..........................................................................................102

12.6.2 Application of Prime Coat................................................................................103

12.7 TACK COAT..............................................................................................................104

12.8 ASPHALTIC CONCRETE SURFACING................................................................104

12.8.1 Preparation of Existing Surface..........................................................................104

12.8.2 Weather Limitations...........................................................................................104

12.8.3 Asphalt Laying procedure....................................................................................104

12.8.4 Compaction Procedure.........................................................................................105

13.0 SPECIAL EQUIPMENTS............................................................................................106

13.1 PNEUMATIC TIRED ROLLER..............................................................................106

13.2 BACKHOE.............................................................................................................106

13.3 FACE SHOVEL......................................................................................................106

13.4 MOTOR GRADER.................................................................................................107

13.5 ASPHALT PAVER FINISHER.............................................................................107

14.0 SPECIAL TESTS...........................................................................................................109

14.1 ATTERBURG LIMITS DETERMINATION........................................................109

14.1.1 Liquid Limit Determination.................................................................................109

14.1.2 Plasticity Limit Determination.............................................................................109

14.2 SIEVE ANALYSIS TEST........................................................................................110

14.3 PROCTOR COMPACTION TEST...........................................................................110

14.4 FIELD DENSITY TEST BY SAND CONE METHOD..........................................111

15.0 PROBLEMS AND THE EXPERIENCE ENCOUNTERED.......................................113

16.0 SAFETY.......................................................................................................................114

16.1 SAFETY PROCEDURES......................................................................................114

17.0 CONCLUSION..............................................................................................................115

IV

LIST OF FIGURES

Figure :2.1 Structure of the organization for the building site.............................................62

Figure : 3.1 Levelling the beam and slab form work............................................................68

Figure : 6.1 Brick shape........................................................................................................80

Figure: 6.2 Types of blocks..................................................................................................81

Figure : 6.3 stress distribution in a masonry wall.................................................................83

Figure : 6.4 Stretching bond..................................................................................................83

Figure : 6.5 Heading bond...................................................................................................84

Figure : 6.6 English bond......................................................................................................84

Figure : 6.7 Flemish bond.....................................................................................................85

Figure : 5.7 Flemish bond....................................................................................................85

Figure : 6.8 English cross bond.............................................................................................85

Figure : 6.9 Construction of wall..........................................................................................86

Figure: 6.10 Lintel arrangement...........................................................................................87

Figure : 9.1 Structure of the organization for road site.........................................................92

Figure :12.1 Cross section.....................................................................................................97

Figure : 14.1 Dry Density Vs Moisture Content.................................................................111

V

LIST OF TABLES

Table : 2.1 About the building site details..............................................................................61

Table : 3.1 Minimum period for removing form work...........................................................67

Table: 6.1 Mortar for brickwork...........................................................................................82

Table: 6.2 Mortar for block work.........................................................................................82

Table : 9.1 About road site details..........................................................................................91

Table : 12.1 Introduction about the materials.........................................................................97

Table : 12.2 Requirements of sub grade materials..................................................................99

Table : 12.3 Requirements of sub base materials.................................................................100

Table :12.4 Grading requirements for sub base materials....................................................100

Table : 12.5 Grading requirements for ABC materials.........................................................102

Table : 12.6 Relationship between prime coat and temperature...........................................103

Table : 12.7 Grading Envelope for Sand for Prime Coat......................................................103

Table : 12.8 Relationship between rollers and their speed...................................................105

VI

Documents

pre contract