Guidelines & Specifications - Civil & Tower Works-PDF

GUIDELINES & SPECIFICATIONS FOR CIVIL & TOWER WORKS

INDUS TOWERS LIMITED

Prepared By: Sadanand khodankar Approved By: Nav Ratan Mahani

Guidelines & specifications for civil & tower works Page 1 of 32

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INDEX

S.No. Description 1 Brief Overview 2 Broad Expectations from Civil Vendors 3 Guidelines & specifications for civil work 4 Material & Quality Standards 5 Recommended Practices at Sites 6 Approved Laboratories for Material Testing 7 Relevant Indian Standard Codes At a Glance 8 Safety Instructions


1. Brief Overview This document is primarily intended towards our esteemed business partners, executing required Civil Works for Site Built-up. The document explains in detail the expectations, guidelines, specifications. Our business partners are expected to go through the document carefully and ensure its compliance in true spirit. The document entrusts a lot of responsibility on Civil Vendors to take care of quality of work being executed, following standard processes and guidelines and ensuring timely delivery of sites. Compliance of this document is mandatory on the part of Civil Vendor / Contractor. This document is indicative only and not exhaustive. The document does not relieve the Civil Contractor from the responsibility of following other established civil constructions norms and processes, not mentioned herein. Any non-compliance observed by Indus, or any agency authorized by Indus to do so, at any stage, shall be treated as breach of Quality Policy and Indus reserves the right to take suitable action against concerned at its sole discretion.


2. Broad expectations from Civil Vendors: • Vendors are expected to work as per INDUS Guidelines .Specifications,

Quality Processes, Defined SLAs. • Not to deviate from Drawing / Design & Specifications in any situation. • Any deviation (for any reason) shall be only through written consent from

SP / PMC and approval from INDUS. • Vendor shall liquidate punch points of the Quality Audit Agency with full

honour and within the stipulated timelines. • Vendor shall not try to influence / pressurise Quality Audit Agency in any

means to compromise on the quality issues. • Quality Assurance shall be put into the system to minimise repetition of

punch points. • Quality shall be a part of system rather than treating it as a separate one. • Quality tools can be used as cost saving tools, as rework increases costs &

reduces profit margins. Do the works write at first time. • Vendor to deploy a qualified engineer during project phase till site hand over

to SP / Indus.


3. Guidelines & specifications for civil work 3.1 Site Survey

For RTT sites following points to be checked while surveying the site, • See the physical site condition of the site. • Building should be with frame structure (RCC Columns & Beams) • Building should be with minimum 3-4 storied • Proper approach road should be available to reach the material vehicles at

site. • Space for material lifting should be available at site. • Proper space for Electrical earthing should be available. • Proper separate 24x7 accesses should be available. • Site should be located at a distance of twice the height of Indus

communication tower from the high tension electrical wires.

For GBT sites following points to be checked while surveying the site, • Proper plot size should be available. • Proper approach road should be available to reach the material vehicles at

site. • See the soil conditions, should not be water logged. • See the land use of the sites. • Site should be located at a distance of twice the height of Indus

communication tower from the high tension electrical wires.

3.2 Site documents to be available before starting the work

• Site lay out in agreement with landlord. • Approved Foundation design. • Municipal corporation approval


3.3 SPECIFICATIONS OF CIVIL MATERIALS: For all materials describe below, It will be vendor responsibility to make available all civil materials at site as per specifications and parallel check from the site civil supervisor/site engineer/civil engineer before using them. It will also be vendor responsibility of returning back surplus material to warehouse.

• CEMENT (Confirm- IS:269-1978)

It is vendor responsibility to provide the good qualities of cement as per following specifications: • Grade of Cement: 43/53-grade Ordinary Portland Cement (OPC) unless

specified otherwise. Some Physical Rough Field-Test: • Check Mixing of Ash: -Take a certain amount of cement in your fingers and

throw in a bucket of water, it sinks into water means it is free from any mixing of ash.

• Open a bag of cement and insert your hand inside, if you feel slightly cool means it is of good quality.

• Check for Deterioration: - Take an amount of sample and rubbing in your hands if it feels like smooth powder it means is not deteriorated. Grittness indicates deterioration.

Approved Brand / Make : Birla-Uttam, Birla–Chetek, L&T, JK ,Ultra Tech,ACC, Gujrat Ambuja, Birla Plus, Vikram , Shree or ISI-marked as per approval of Engineer-in- charge.( For all other brands prior approval is must.)

• REINFORCMENT STEEL— High Strength Deformed Bar (Confirm IS: 1786-1985) All reinforcement shall be free from loose mill scales, loose rust and coats of paint, oil, mud or other coatings, which may destroy or reduce bond .It should be deformed/tor bar of grade Fe415. Approved Brand / Make – SAIL,TATA , RATHI,KAMDHENU as per IS: 1786.( For all other brands prior approval is must.)


• SAND / FINE AGGREGATES Fine aggregates shall consist of natural sand resulting from natural disintegration of rock and which has been deposited by streams or glacial agencies, or crushed stone sand or crushed gravel sand. • It should be free from adherent, clay, mica and inorganic impurities. • It should be clean, sharp, angular (gritty to touch), hard and durable.

For all works it should be coarse sand except for plastering works, which require fine sand. All sand is generally found to contain some % of silt i.e. not more than 6% except Stone Crusher sand. For ordinary masonry work, for concrete etc., sand should pass through a sieve of 2mm x 2mm mesh. For fine works, plaster, pointing etc, sand should pass through sieve No-14 or 16BS-1mm sieve.

Note ; Crushed stone is not so satisfactory as natural sand since crushed stone contains a lot of the fine particles like dust.

• COARSE STONE AGGREGATE ( Confirm IS: 383-1970) Aggregates shall not contain any harmful material, such as iron pyrites, coal fragments, shells, organic impurities etc., in such quantities as to affect the strength or durability of concrete and in addition to the above, for reinforced concrete, any material which might cause corrosion of the reinforcement. General Characteristics:

• It should be hard, strong non-porous and free from laminated particles. • It should have angular or roughly cubical in shape and in no case it should

be round shape. • It should be well graded i.e. aggregate should be ordered in separate sizes

and recombined in the proper proportion while batching or before batching. • Aggregate sizes: - For RCC work it should have 20mm and for PCC 40mm

nominal sizes. A 40mm nominal max. Size aggregate will be ordered in three different— 40mm to 20mm, 20mm to 10mm and 10mm to 4.75mm.

A 20mm nominal max. Size aggregate will be ordered in two different— 20mm to 10mm, 10mm to 4.75mm.


• WATER Water used for cement concrete, mortar, plaster, grout, curing or washing of coarse aggregate shall be clear and free from injurious amounts of oil, acid, alkali, organic matters or other harmful substance in such amounts that may impair the strength or durability of the structure. Portable water shall generally be considered satisfactory for mixing and curing of concrete.

• BURNT BRICKS Burnt bricks shall have a minimum compressive strength of 105Kg/cm.sq. for Class designation-105. They shall be sound, hard and well burnt with almost sharp edges, free from more cracks. They shall give a clean metallic sound when struck together. Bricks broken to examine the texture shall show that they are of clean, homogeneous, and free from stones and lumps.

• SETTING OUT

The contractor shall be responsible for the true proper setting out the works in relation to original points, line and levels of reference and for the correctness of the levels, dimensions and alignment of all parts of work and for the provision of all necessary instruments, appliances and labor in connection therewith. If at any time during the progress of work any error appears or arise in the position of levels, dimension or alignment of any part of work, the contractor will be responsible to rectify the same at his own expenses to the satisfaction of the engineer-in-charge. The contractor shall layout one or more permanent benchmarks in some where within plot before the start the work, from which all-important levels for the work will be set.


3.4 PCC & RCC WORK GENERAL Scope:

This specification establishes the material, mixing, placing, curing etc of all type of cast-in-situ concrete used in foundation, underground and over ground structures, floors etc. Any special requirements as shown or noted on the drawing shall govern over the provisions of this specification. Codes:

All design and construction shall be performed in accordance with the IS code of practice for plain and reinforced concrete IS: 456.

3.5 MIXING OF CONCRETE

The mixing of concrete shall be strictly carried out in a mechanical concrete mixer. The mixing equipment shall be capable of combining the aggregates, cement, sand and water within the specified time into a thoroughly mixed and uniform mass, and of discharging the mixture without segregation. The entire batch shall be discharged before recharging. The mixing period shall be measured from the time when all the solid materials are in the mixture drum, provided all of the mixing water shall be introduced. The mixing time in no case shall be less than two (2) minutes & shall be continued until there is a uniform distribution of materials and the mass is uniform in colour and consistency. The contractor has to find suitable safe place to operate the mixing machine .

Normally, hand-mixing of concrete shall not be permitted, but where it is not possible like for roof top tower foundation or for smaller quantity, hand mixing can be allowed as per approval of engineer-in-charge. For hand mixing 10% extra cement shall have to be added to the normal mixes. It shall be carried out on a water tight platform and care shall be taken to ensure that mixing is continued until the mass is uniform in colour and consistency.


3.6 PLACING OF CONCRETE

• Before placing concrete, all equipment for mixing and transporting the concrete shall be cleaned and all debris shall be removed from the place to be occupied by the concrete. All form and soil surfaces shall be finished to desired levels and shall be thoroughly wetted immediately prior to placing of concrete.

• Concrete shall be handled from the place of mixing to the place of final deposit as rapid as practicable by methods which will prevent the segregation or loss of any of the ingredients.

• The concrete shall in no case be dropped from a height of over 1.5m and it shall be carefully laid in position. Concrete shall not be done unless the form work conforms to the shapes, line and dimensions as shown in drawings. The form work should be sufficiently rigid during placing and compaction of concrete and no segregation of aggregates shall take place. The method of placing and compaction employed in any particular section of work shall be entirely to the satisfaction of the Engineer-in-charge.

• To ensure bond and water tightness with old concrete surface, they should be cleaned and roughened by wire brushing & chipping. The bonding of old and new concrete should be done by applying the cement slurry /binding compound after thoroughly watering the old concrete surface and removing all free particles.

• Unless otherwise approved, concrete shall be placed in single operation to the full thickness of slab, beams and similar members and shall be placed in horizontal layers not exceeding 1m deep in walls, columns and similar members. Concrete shall be placed continuously until completion of the part of work between construction joints or as directed by the Engineer-in-charge.

• Concrete shall not be started unless the electrical conduits, fan hook or any other piping wherever required are laid by the contractor.

• Before concreting, the contractor shall provide, fabricated and lay/fix in proper position all metal inserts, anchor bolts, pipe etc. as per the relevant drawings and at the direction of the Engineer-in-charge.


• Where concrete is placed in soil, it shall be placed only of firm

undisturbed ground. Any concrete that is placed on a well compacted fill shall have the prior approval of the Engineer-in-charge.

• The concrete after being laid shall be compacted by means of vibrators of approved type under proper supervision as directed by the Engineer-in-charge or technical person. Vibration shall not be confined only to the top surface, but the whole mass of concrete shall be well vibrated until the dense mass assume jelly like appearance and consistency, water just appearing on the surface. Over vibration or vibration of mix, which have too much of water shall be avoided. Care should be taken to avoid segregation and formation of air bubbles.

• Concrete shall be compacted with mechanical vibrator equipment supplemented, if necessary, to obtain consolidation then we can use

hand spading and tamping also .Care should be taken to prevent contact of vibrators against reinforcement steel. Vibrator shall not be allowed to come in contact with forms or finished surfaces. The vibrator shall penetrate the layer being placed and also penetrate the layer below while the under layer still plastic to ensure good homogeneity between the two layers and prevent the formation of cold joints.The whole process starting from the mixing of concrete the placing and compaction shall not take more than twenty-(20) minutes i.e. the process should be completed before initial setting takes place.

3.7 CURING

Curing shall be accomplished in accordance with IS:456 by keeping the concrete covered with Jute bag or similar absorbent materials, which will be kept constantly, wet for at least seven (7) days from the date of placing of concrete unless otherwise specified. In very hot weather, precaution shall be taken to see that the temperature of the wet concrete does not exceed 38-degree C while placing. Heavy loads shall not be placed on or moved across floor slabs until curing is complete. Care should be taken to prevent floor surface from being marred/spoiled/damaged during the curing period. Fresh laid concrete formwork shall not be jarred/shaken.


NOTE: Comparative Strength of OPC at various ages.

Days of curing

% Compressive Strength

3 days 40% 7 days 65% 28 days 100%

3.8 CONCRETE TEST / OTHER CIVIL MATERIAL OR WORK TEST

Sampling and testing of concrete shall be conducted in accordance with the latest issue of IS: 1199And IS: 516. The frequency of tests shall depend upon the direction of Engineer-in-charge.The sampling for the testing will be as per IS:456.

• Cube Test (Compression Test)

Compression test is carried out to determine whether the concrete being produced complies with the strength requirements specified. The test will be made in accordance with IS:516. The size of cube are 15cm x 15cm x 15cm. Normally 7-days or 28-days tests are made on different specimens. As per IS:456 following are the minimum values of test results after curing for 7& 28-days in respect to different concrete mix. Concrete Grade… M15 M20 Compressive Strength :- 10.0 13.5

on 15cm Cubes(N/mm.sq.) After 7-days. Compressive Strength :- 15 20 on 15cm Cubes(N/mm.sq.) After 28-days.


• Concrete Cube for Laboratory Test: - The cube shall be taken at site during casting in front of site engineer. Take min. 6-Nos. of cubes.

NOTE :- If the Engineer-in-charge is not satisfied from any materials like bricks, cement, sand and reinforcement steel etc. and any work done then INDUS Towers can go for their test ( Laboratory / Physical) from third party which will be finalized by Indus only. These all test will be done as per IS code specifications.

3.9 FORMWORK / SHUTTERING Form work for concrete in foundations/super structure shall be plywood, steel, good seasoned timber or other approved materials as directed by the engineer-in-charge. Formwork shall be properly designed so that it will be easy to remove and clean. It should be sufficiently tight to prevent loss of cement slurry from the concrete. All joints and holes in the formwork shall be closed with putty, jute cloth or other approved materials to the satisfaction of Engineer-in-charge. The inner face of the shuttering shall be cleaned and thoroughly wetted or greased with approved material. Care should be taken that such coating is kept free from concrete with the reinforcement. The stripping time for the shuttering and formwork shall be confirmed by the Engineer-in-charge as per IS:456. Under no circumstances shall the contractor attempt to cover up honeycombed concrete or otherwise attempt to camouflage/cover bad work. After removal of formwork the engineer-in-charge shall examine the surface of the concrete and shall give instructions for it proper finishing. In case of bad concrete work, the engineer-in-charge may require the contractor to demolish the entire structure or part thereof and reconstruct it without any claim.


3.10 BRICK WORK IN MASONRY

Brickwork shall be laid with specified mortar to be prepared in accordance with IS:2258. It shall be of cement and sharp coarse sand and shall be made in small quantities so as to be used up within 30-minutes. The cement and sand in required proportion, shall be first mixed dry thoroughly and then water added and mixed to a sufficient thick consistency as required by the engineer-in-charge. No left over mortar shall be used. The mortar recommended shall be of the following proportion unless mentioned;

• 1:5 for brick of a thickness of not less than 21cm. • 1:4 for brick piers, half brick wall, honey combed brickwork and

hollow blocks. • Soaking of bricks

Brick required for masonry in cement mortar shall be thoroughly soaked in clean water or wetted by pouring of water before use for at least 6-hours and until air bubbles cease to come out. The soak bricks shall be kept on wooden planks or back platform to avoid earth being smeared/dirty on them.

• Curing

Masonry work as it progresses shall be kept thoroughly well watered on all faces for at least 7-days after completion.

3.11 DPC AT PLINTH (1:2:4) & BITUMINOUS APPLICATION

The surface has to be properly cleaned with brushes and splashed with water. The damp proof course shall be 40mm thick with cement concrete 1:2:4 (1-cement:2-coarse sand:4-12.5mm nominal size aggregate). This should be mixed with water proofing compound and applying a coat of hot bitumen 1.7kg/sq.m. on DPC after the concrete surface is thoroughly dry. The surface should be cleaned with brushes before application of the bitumen layer.


3.12 CEMENT PLASTER

• Preparation of surface

The surface, to be plastered, shall be thoroughly cleaned so that it is free from dust, dirt. Oil. Salts etc. The joint of brickwork shall be raked out properly. On cement concrete surface, the surface shall be cleaned with wire brush and scarified by lines with trowel or backed by chisel. The surface in both cases shall be washed properly and kept wet for 4-hours before plastering is commenced.

• Mortar The mortar mix shall be used at site as per mentioned in particular item of the specs agreed.

• Plastering

Plastering shall be started from the top and gradually worked down towards the floor. The thickness of plaster shall be as per specified. To ensure an even surface, plaster pads of about 10cm x 10cm shall be first made horizontally and vertically at not more than 2m interval over the entire surface to serve as gauges. The mortar shall then be applied on the wall or the surface between the gauges and finished even. Rounding chamfering corners, junction etc. wherever required shall be done by the contractor. If specified in item, chicken mesh of sufficient width to extend over the uncommon material and fixed by nail before plastering is done.

• Curing

Curing shall start 24-hours after the plaster is laid. It shall be kept wet for 7-days. During this period, it shall be suitably protected from all damages at the contractor expense. Any cracks, which appear on the surface and all portions found hollow when tapped, or are found to be soft or otherwise defective shall be cut out in rectangular shape and redone as directed by the Engineer-in-charge.


3.13 FLOORING

General

Flooring shall consist of a sub-base laid on the compacted earth or sand fill as required, as base course laid on the sub-base and then a finished layer of concrete or any other material, as specified, to be laid. The material for filling (earth or sand as specified) shall be brought from the source as approved by the engineer-in-charge.

• Filling

The surface to receive the filling shall be first cleared free of all roots, vegetation and wetted. Filling in plinth or other specified levels shall proceed in layers of 15cm along with the construction of building. It shall be watered and well rammed in layers as mentioned above and compacted to the satisfaction of the engineer-in-charge. Care should be taken to remove all roots, vegetation, foreign matter etc. from the earth used for filling. Where sand filling is specified, the sand shall be clean, free from vegetation and other deleterious/ harmful materials. In case of sand filling, flooding shall be done to achieve compaction if required.

• Preparation of bed

The bed for flooring shall be prepared with level or slope as instructed by Engineer-in-charge. Care shall be taken so that there are no roots, vegetation, foreign matters etc.

• Sub-base

On the prepared bed as indicated above, boulder or gravel or broken brick or cement concrete as specified in drawing/item as per IS:456 shall be laid to thickness as specified in drawing/items. The layer shall be beaten with hammer until thoroughly consolidated. All the material used shall conform to the required specifications. The materials, proportion, mixing laying curing etc for concrete shall be carried out as specified. The finished work shall have uniform and even surface over the whole floor or as directed by the engineer-in-charge.


• Sand layer

The sand layer shall be spread in one or more layers to the thickness as indicated in drawing or quantity specification, watered and rammed.

• Base Course

Cement concrete shall be of specified mix as indicated in drawing/item. Cement concrete shall be placed in position with or without reinforcement as shown in drawing/as indicated in item and beaten with trowel/scuffle and finished smooth with neat cement or left rough as directed by the Engineer-in-charge.

3.14 PAINTING

Plastered surface shall be thoroughly cleaned of dust, dirt, grease, oil marks etc. before the coat is applied. All the holes and depressions should be filled with gypsum prior to application of the paint. The surface shall be wetted with clean water before paint is applied. The colour of paint shall be indicated in item specs or as per the Engineer-in-charge. All paint should be done with the help of paintbrush only.

• Oil bound paint

First coat shall be followed with base primer and if the plastered surfaces are not smooth, it shall be made smooth by using proper filling material over the base primer and then applied the coat of oil bound paint on it as per specified no. of coats. It is generally done inside the rooms.

• Snowcem Paint

It shall be done on the out side of building and boundary wall and applied 2/3-no. of coats as per specified in item specs. Curing shall be done for min 7-day. It must be up to the satisfaction level to the Engineer-in-charge.


• Synthetic Enamel Paint

Synthetic enamel paint of approved brand and manufacture and of required shade shall be used for the topcoat only. The paint for the under coat(base primer) shall be as recommended by the approved manufacturer. The surface shall be thoroughly cleaned. All dirt, scales and grease shall be removed before painting is started. The surface should be perfectly dry to permit good absorption.

3.15 WATER PROOFING OF ROOF SLAB

Water proofing treatment shall be given to the RCC roof slab by laying tar felt sheet, hot bitumen, mud-Phuska and top with brick tilling. The following procedure shall be adopted. • The surface should be completely dry. • Clean the surface. • Lay the tar felt sheet all over the roof area. At joint in between the sheets,

min 150mm overlap should be given. All joints in between the sheets and at the edges near parapet should stuck to parapet & roof surface by providing adhering material bitumen.

• Lay a thick layer of bitumen 1.45kg/sq.m all over the sheet. • Lay mud-Phaska by providing proper slope towards rain water pipe with

proper compaction. • Lay the brick tiles by providing 10mm joint thickness. Remove the mud

from the joints up to tile thickness, the tipping the joints with mortar mix 1:3. Proper slope at least 2-inches towards rain water pipe should be maintained.

• Top surface of tile shall be finished with thick neat cement slurry.

3.16 ANTI TERMITE TREATMENT (For Ground base site)

It should be done as & where applicable by providing and injecting chemical emulsion for pre-constructional anti-terminated treatment and creating a chemical barrier along the external perimeter of the building and in the foundation pits before placing the PCC. Any one of the following chemicals (as specified) in water emulsion shall be used. • Dieldrin emulsifiable concentrates (IS:1054-1962) 0.5% • Aldrin emulsifiable concentrates (IS:1307-1958) 0.5% • Heptachlor emulsifiable concentrates 0.5%


4. Material / Quality Standards:

• It is recommended to use Pre/Ready Mix Concrete for the GBT sites.If available in the nearby area.

• Grade of Cement – Shall be 53 Grade (IS: 12269) OPC for RCC & 53 or 43 Grade (IS: 8112) OPC for PCC works.

• Brand of Cement – L&T, Ultra Tech; ACC; Gujrat Ambuja, Birla Plus, Vikram, Shree.

• Life of Cement – Cement shall be used within 45 days from manufacture date

• Grade of Reinforcement – Fe 415 Grade TMT Bars only • Make of Reinforcement – TATA, SAIL, ISPAT, RATHI,KAMDHENU as

per IS: 1786 .( As per best brand available in circles) • Concrete Mix – RCC – M20 ( 1:1.5: 3); PCC – M10 (1: 3: 6) • Cement Qty – M20 – 8 bags / m3 of Conc; PCC – M10 – 4.25 bags / m3 of

Conc. • Water cement ratio – for M20 – 0.55 (30 litres / 50kg bag of cement); for

M10 – 0.68 (34 litres / 50kg bag of cement). • Quality of water – Clean / potable water shall be used for concreting. Water

from dewatering shall not be used. • Quality of aggregates – Coarse / fine aggregates shall be free from organic

impurities. Sand shall be free from silt, dust, etc. If silt / dust found in excess sand shall be washed before use

• Sand / fine aggregate quality – Sand shall be free from silt, dust, etc. If silt / dust found in excess sand shall be washed before use.

• Machine Millar shall be used for concrete mixing for all stages. Minimum mixing time shall be 2 minutes

• Vibrator (40mm / 60mm) shall be used for all stages • Concrete cover blocks shall be provided • Good quality steel shuttering material to be used. Face of shuttering shall be

clean and treated with form releasing agent. • Fast setting agent / compounds need to be used wherever, required. • Only A- Class Bricks (105kg/cm2 strength) to be used.


5. Recommended Practices at site :

5.1 General : • Copy of Site Layout & Foundation design drawings shall be kept available

at site at all times. • It is recommended to use pre-mixed concrete if available in nearby area. • Carry out concreting in good weather conditions only. Discourage

concreting in night times / poor lighted conditions • Any deviation having prior approval of Indus and SP/PMC to be marked on

drawing and signed jointly by Civil Contractor & SP/PMC Engineer. • To ensure that checklists and pour cards are signed at all stages as specified.

Same to be retained in good condition and submitted alongwith bills • Minimum cover to main reinforcement shall be as per the drawing • Concrete cover blocks can be made at site in bulk. • Lap / development length shall be as per drawing or atleast 45 dia. • Care shall be taken to avoid honey combs during concreting • No construction joint other than specified shall be permitted • Removal of formwork shall be carried out after a minimum period of 24 hrs

after concreting • Concrete cube samples (raft / footing stage – 6 nos.) shall be taken and

tested at 7th & 28th days and reports submitted to client. • Column alignment shall be as per drawing. Eccentricity is not acceptable. • Template shall be placed as per design, exactly in the centre of the column

and in water level. Supports shall be provided to template bracing members in between two columns.

• Foundation bolts should be as per design / drawing meaning diameter, length and threading length, etc. Nuts should be inserted with some friction. Incase if, nuts are getting inserted easily then same should be brought in knowledge of SP/ PMC and INDUS.

• Civil Vendors to ensure timely intimation notice before 48 hours to SP/ PMC and INDUS.

• Non-readiness of the site from civil vendors should not happen after offering the same for inspection.


• Civil Vendors to complete excavation work before calling for inspection. • Correct water cement ratio is used as per approved standards. • PCC thickness should not be less and quality should be upto mark. • Adequate chairs and spacer bars are used to hold the reinforcement in

position • Vibrators are not to be used continuously as per guidelines during all three

stages of concreting • Pedestal level difference is being checked / rectified at the time of

concreting. • Concreting is to be done during day light only. In exceptional cases if

concreting needs to be done in night, proper lighting should be arranged. • Bolt projections above pedestals should be thoroughly checked before taking

up concreting of pedestals 5.2 Excavation :

Below is the common & ideal procedure for excavation • Layout shall be marked on ground before starting the excavation • Wooden or steel rod shall be pegged outside excavation area such that

footing centre lines can be derived • Once excavation is done then line dori shall be tied between pegs and

column centre points can be transferred on ground • Before putting PCC pit dimensions & pit symmetry with respect to centre

lines should be verified. • Ensure column is exactly in centre of footing and there is no chance of

template eccentricity • Eccentricity of base plate with respect to column centre is structurally in-

correct • If any level difference in existing ground is found, then soil excavation shall

be with reference to the lower level and the soil shall be back filled upto the top most level of natural ground level to avoid soil erosion.

5.3 Backfilling: • In case required depth is not achievable for any reason, then revised drawing

shall be taken and implemented


• Provision of sand bed / rubble soling shall be verified from the soil consultant / foundation designer in case of marshy or clay soil

• In case of dry soil with no water table, all foundation pits shall be soaked with water for 24 hours and compacted well prior to laying PCC

• Loose pockets in foundation pits shall be completely removed and back filled with PCC

• Foundation pit shall be kept dry (free from water) during laying of PCC & RCC and further for a period of 48 hours from the time of concreting

• All back filling shall be done with good soil (preferably murrum) free from organic impurities and boulders.

• Soil back fill shall be done in layers of 200 – 300 mm starting from centre towards the end and densely compacted and sprinkling min. water as necessary for compaction.

• After completion of back filling and compaction, 100mm high earth bund shall be made along sides and the area shall be filled with water for atleast 24 hours.

• Backfilling should be with proper watering and compaction. • Boulders, Black cotton & soil with organic impurities are not to be used for

back filling. In case excavated soil is black cotton / hard rock then murum should be brought from out side for backfilling.

• Backfilling should be done in 300mm thick layers with watering and compaction.

• Back filling should start only after the approval of site-in-charge. 5.4 Reinforcement:

• Reinforcement shall be bent and fixed in accordance with relevant IS Code • Reinforcement steel shall not be re-bent or straightened • All reinforcement shall be placed and maintained in position as per drawings

by providing cover blocks, chairs, spacers, etc • Cross bars shall not be welded • Rough handling or dropping of reinforcement from height shall not be

permitted.

5.5 Curing: • Curing of foundations shall be carried out over a min. period of 7 days in the

following manner-


• Base raft, beam shall be kept continuously in damp or wet condition by ponding or covering with sacking for a minimum period of 2 days after final setting time of concrete ( 12 hrs)

• Back filling shall start after 72 hrs of concreting • After completion of back filling the soil shall be kept moist/ damp/ wet

condition until 7 days from concreting • Tower Erection shall start after 7 days of concreting and anchor bolt setting. • Continuous curing should be done. Just spreading water at fixed intervals in

a day not acceptable. Ponding and continuous watering should be done. • It is recommended to use any of the below mentioned curing admixtures to

take additional precaution. Quick strength gaining – compound – CONPLAST NC – 85% strength

attained in 5 days. Quantity – 1.5 litres/bag of cement. Curing Compound – Requires no watering of surface applied for. Compound – CONCURE WB The strength is attained by concrete as per the normal course.

Application is by brush or spraying to concrete surface-after 60 mins (immediately after concreting) to the surface exposed to atmosphere-immediately on removal of side shuttering. 1 litre can be applied for an area of 5 sq. meters. (Both are of FOSROC make).

5.6 Grouting:

• Surface to be grouted shall be thoroughly roughened and cleaned of all

foreign matter and laitance. • Anchor bolts, anchor bolt holes and the bottom of column base plates shall

be cleaned of all oil, grease, dirt and loose material. The use of hot strong caustic solution for this purpose will be permitted.

• Prior to grouting, the hardened concrete surfaces to be grouted shall be saturated with water.

• Water in anchor bolts holes shall be removed before grouting is started. • Forms around base plates shall be reasonably tight to prevent leakage of the

grout. • Adequate clearance shall be provided between forms and base plate to

permit grout to be worked properly into place. • Grouting, once started, shall be done quickly and continuously to prevent

segregation, bleeding and breakdown of initial set. Grout shall be worked one side of one end to the other to prevent entrapment of air.


• Below specifications shall be followed for the grouting of Tower base plate:

For equal or less than 50mm thickness Cement Mortar of proportion 1:4 shall be used along with one of the following admixtures

• Sika admixture – Interplast – EP&N 200 or • Fosroc admixture – Cebex 100 or • Any other tested equivalent. Manufacturers’ recommendation shall be followed for deciding the proportion of admixture to be used. Alternatively, one of the following cementitous grouting materials can be adopted with INDUS’s approval in lieu of the above mixture. • SikaRep – Microcrete; or • Conbextra GP or Degusa constructional chemical – Masterflow 918 or • Any other tested equivalent.

For more than 50mm thickness:

Cement concrete of proportion 1:1.5:3 (aggregate – baby chips) shall be used along with one of the following admixtures: • Sika admixture – Interplast – EP&N 200 or • Fosroc admixture – Cebex 100 or • Any other tested equivalent. Manufacturers’ recommendation shall be followed for deciding the proportion of admixture to be used. Alternatively, one of the following cementitous grouting materials can be adopted with INDUS’s approval in lieu of the above mixture.

• SikaRep – Microcrete; or • Conbextra GP or • Degusa constructional chemical – Masterflow 918 or


• Any other tested equivalent.

Need to give focus on the following:- • All base plate should be in one level. Level difference should be zero. • Grouting under the base plate should be done as per recommended

specification. • Base plate thickness should be seen after grouting at all sides. • Ensure plastering / finishing done to pedestal top and sides in line & level.

On top slope should be provided to prevent water stagnant around base plate.

Template & foundation bolts placement • Template should be exactly in center of the columns. • All templates should be in one level. • Check nut below template should be kept at starting of the threading of the

bolts. • Check nut bottom should be top of the column concrete & all columns

concrete top should be in one level.

5.7 Criteria for non acceptance of Foundation civil works • Excavated depths not achieved / done as per design drawings. • Deviation in reinforcement placement in terms of size, numbers & cutting

length. • Punch points not attended / rectified and proceeded with work. • Eccentricity in placing column bars with respect to footing centre • Cement beyond limit (should be within 45 days of manufacture). • Non usage of mixer / vibrator. • Deviation in workmanship like mix proportions, maintaining water cement

ratio, etc. • Any stages of work carried out in absence of Audit Agency. • Concreting during night time without proper lighting arrangement. • Any other issue which is critical to the safety & quality of foundation as

decided by SP / PMC / Audit Agency / INDUS.


6. Approved Laboratories for Material Testing Civil Contractor shall arrange 3 cube at every Concreting stage occurred during three stage inspections for GBT & two stage inspections for RTT sites for testing purposes. Civil Contractor will submit the Cubes (taken at site) Test reports (List of Approved laboratories as mentioned below) to Audit Agency in original & its copy, duly received by Audit Agency. Other than list below, Govt. approved, CPWD, PWD, Engineering collage laboratories can be used for tesing. Approved Laboratories

S.No. Name of Laboratories Location 1 Thapar Engineering College Patiala 2 Punjab Engineering College Chandigarh

3 Regional Engineering College(Dr.B.R Ambedkar National Institute of Technology) Jalandhar

4 Guru Nanak Dev Engineering College Ludhiana 5 Guru Nanak Dev University/Engineering College Amritsar 6 Giani jail Singh Engineering College Bathinda 7 REC Kurukshetra 8 IIT New Delhi 9 Delhi College of Engineering New Delhi 10 Shriram Institute New Delhi


7. RELEVANT INDIAN STANDARD CODES AT A GLANCE Towers are designed, manufactured, erected and commissioned in accordance with relevant National Standards:

• Angle Sections of structural grade IS:2062-1992/ IS:226

• Code of practice for use of structural steel in overhead transmission line towers: materials, loads and permissible stresses (sec1&2) IS:802 (Part-1)-1995, IS-806

• Hexagonal nuts (size range- M5 to M36 IS:1363-1992-part3)

• Technical supply conditions for threaded steel fasteners IS:1367-1980

• Specifications for hot dip zinc coatings on structural steel and allied products

IS:4759-1984

• Hexagonal bolts for steel structures IS:6639-1972

• Tolerance for fabrication of steel structures IS:7215

• Bolts shall be of 5.6 Grade as per IS:12427

For items not covered by National Specifications, Indus towers specified specifications are to be followed.


8. SAFETY INSTRUCTIONS: Safety Instructions: “An accident may occur if the safety precautions are neglected. This type of accident may be fatal or cause serious injury. It may also damage the product.” For WIP sites both RTT & GBT sites proper Red colored safety indicator Tape along the periphery of site should be placed. The following special symbols are used to indicate the risk of radio frequency radiation, electrical hazards and electrostatic discharge:


8.1 Electrical Hazards:

• Direct contact with the mains power and indirect contact via damp items or moisture can be fatal.

• Improper electrical installation may cause fire or electrical shock. Approved circuit breakers for the AC mains and the specified cable’s cross sectional areas must always be used.

• Only a qualified and authorized electrician is permitted to install or modify the electrical installation.

• Verify that the cable markings correspond before connecting /disconnecting

cable.

• Batteries can be hazardous if improperly handled. Special care must be used to prevent short-circuiting batteries, or loss of electrolyte. Electrolyte contains potentially hazardous material.

“Refer to operation’s manual of a specified manufacturer.”

• Short circuits can cause injury or damage. Although the battery voltage may be low, the released power can be extremely high.

8.2 Working at Heights:

When working on a mast, tower or a roof, the following precautions must be taken:

• Personnel working at heights must have the appropriate training and medical certificate.

• Full body safety harness, safety belts, shoe and safety helmet must be used. • Adequate protective clothing is essential in cold weather. • All lifting devices must be tested and approved. • During work on a mast, all personnel in the area must wear helmets.


8.3 Safety instructions for working with Ladders: • Make sure that the ladder is undamaged and has been approved for use. • Do not overload the ladder. • Leaning ladder longer than 5m. • Free-standing ladder with a platform and knee-support, and with over 2

meters height to the platform. • Any other free-standing ladder longer than 3m. • Use the ladder foot or a ladder support to reduce the risk of tipping over

sideways. • Always attach extension legs to a ladder that is to be used on a sloping

base. Never prop up a ladder with boxes, stones or the like. • Extend the ladder completely.

Climbing and using the ladder:

• Climb the ladder facing it. • When you lean sideways, outward from the ladder, your navel should

never be outside the edge of the ladder’s frame. • Always keep 3 points of contact (two feet and one hand, two hands one

foot) with the ladder when working on it. This will reduce the risk of falling.

• Never climb the topmost four rungs of a ladder.

8.4 Handling Heavy Goods:

• Use tested and approved lifting devices only. They must only be used by trained personnel. • Always check that all parts of the lifting devices are intact. • Make sure that all lifting devices are properly stabilized or attached to fixed objects such as walls or buildings before lifting. • Give clear and consistent command signals, for example

− lift − lower − stop



• Make sure that there is never an angle of more than 90_ between the straps at the point where they are attached to the lifting hook.

• Too large an angle between the lifting straps increases the strain on them and may cause them to snap. Overloading, or wrong use of lifting devices in other ways, can have catastrophic consequences.

• Never walk under hoisted loads. • Follow local regulations for safety clothing and safety equipment

for hoisting and moving goods. • Unsecured cabinets have a high center of gravity. They can easily

tip over and harm personnel.

WARNING There is a danger of the assembly toppling over, which could cause injury to personnel or damage to the equipment.

8.5 Fire Safety :

WARNING

Fire may spread to neighbouring rooms. When working on a radio base station you may have to open cable ducts, channels and access holes, thereby interfering with the fire sectioning of the building.

• Close the cable ducts and fire doors (if applicable) as soon as possible.

• After completing work on cables, seal the cable ducts according to the regulations for the building.

• Minimize the amount of inflammable material. • Avoid storing empty packaging material on the site. • Use a powder or carbon dioxide type of fire extinguisher due to

the electric nature of the equipment inside the Radio Base Station.

Documents

Guidelines & Specifications - Civil & Tower Works-PDF