Indian Concrete Institute - ICI brocher 1-20 · 2014-09-23 · ICI Update - April 2011 02 News from Centres Indian Concrete Institute, Ghaziabad Centre and UltraTech Cement Limited

ICI Update - April 2011 01

Contents• From the President’s Desk 1

• News from Centres

th• 16 ICI (KBC) Civil-Aid (Torsteel) Endowment Lecture 6

- Construction of Underpasses in Restricted Boundary Conditions - Er. Jose Kurian

• Selected Seminar Papers 17

- Self Compacting Concrete for the Tallest Building in India - Mr. S.A. Reddi

• 27

• Student Chapters 28

• Forthcoming Events 29

• New Members 32

• Election Notice 33

Strengthening International Relations

From the President’s Desk

April 2011 Vol. 2 Issue: 04

In recent times, ICI has been receiving growing recognition in the international sphere. Our in t e rna t i ona l c on f e r ence , ACECON 2010, was not only co-sponsored by two world-renowned bodies, namely, the American Concrete Institute (ACI) and the Asian Concrete Federation (ACF) but also witnessed participation of experts from nearly two-dozen countries. The Roving Seminars on Sustainability held in January 2011 at Bengarulu, Nagpur, Jaipur and Kolkata were jointly organized by ICI and SINTEF, Norway. The recently-concluded Round Table meetings held at Mumbai, Bengarulu, Chennai, Hyderabad and Delhi were the outcome of joint efforts of ICI and t h e F e d e r a l H i g h w a y Administration, USA. Besides being helpful in disseminating technical information to Indian participants on the latest trends,

these events have enhanced ICI's image in international sphere.

With a view to reinforce this trend, I was quick to respond to ACI's invitation and attended ACI Convention held in Tampa, Fl.

nd thfrom April 2 to 6 , 2011. I made use the opportunity to establish contacts with the ACI President, the Executive Vice-President and other functionaries of ACI. I also met many well-known experts. All of them showed keen interest in the activities of ICI, while some have promised to participate in future ICI events. I witnessed functioning of the two ACI Committee meetings and attended technical sessions on performance requirements and testing. I must admit that all this was a great learning experience! Incidentally, I must acknowledge with thanks the immense help rendered by our GC member Prof Gajanan M.Sabnis during my visit to USA.

ICI can learn a lot from the ACI. Worldwide, ACI is known for its valuable technical documents which contain a plethora of information on a variety of topics in structural concrete. Such

excel lent compilat ion was possible through the painstaking efforts of a large number of technical committees of ACI. I am happy to inform that ICI has also made a small beginning in this direction and a draft document of the first ICI Committee is under circulation. ICI needs to form a number of Technical Committees and commence the work of p r e p a r a t i o n o f t e c h n i c a l documents which could be very useful to practicing professionals in India.

During ACI Convention at Tampa, I attended at least five technical s e ss i ons on pe r f o rmance requirements and testing. The t r e n d o f p e r f o r m a n c e specifications now seems to be p i c k i n g u p i n t h e U S A . Considering the fact that the shift from prescriptive to performance specifications is closely related to sustainability, ICI needs to make some serious efforts in bringing awareness about the new trend amongst its members and Indian professionals.

Vijay Kulkarni

President


News from Centres

Indian Concrete Institute, Ghaziabad Centre

and UltraTech Cement Limited jointly organized

Technical Symposium on March 26, 2011 at

Hotel Royal Residency, Saharanpur.

The function was attended by about 70

Researchers , Eng ineers , Arch i tec ts ,

Consultants from Saharanpur. Er.Rahul Goel,

Regional Head, Technical Services, UltraTech

Cement welcomed the members of ICI and other

delegates from construction industry.

Er.P.C. Sharma, Chairman, ICI Ghaziabad

Centre detailed on ICI and its upcoming event

i.e. National Conference on Repair and

Rehabilitation of Concrete Structures at Noida

during May 6-7, 2011.

ICI-Ghaziabad Centre

Lighting of Lamp by Dr. Rajeev Goel and Sh. Surit RoyDignitaries on the dias

Dinner Question-Answer Session

Er. A.K Sharma, Chief Engineer, CPWD was the

Chief Guest for the evening and delivered a

keynote address on “Durability of concrete

together with repair & rehabilitation methods”

and Er. P.C Sharma delivered his talk on

“Shankh-A novel ferrocement structure at

Ghaziabad”.

Dr. Rajeev Goel, Honorary Secretary, ICI

Western UP Ghaziabad Centre, coordinated the

function. Mr. Surit Roy, UltraTech thanked

every one for their participation and co-

operation for making the event successful. The

function was followed by cocktail dinner.

ICI-Pune Centre, organized a technical lecture

on Saturday 26.03.2011 titled 'Specialised

Concrete' by Er. Yusuf Inamdar at Arkey Engg &

Foundry Services, Pune 411 004. Er. Yusuf

Inamdaar touched upon various types of

special concretes.

ICI-Pune Centre

Er. Yusuf Inamdar delivering his lecture

Organized “ICI-North Bengal Centre” at Siliguri,

District Darjelling, West Bengal Organized a

technical lecture on “Repair and Rehabilitation of

concrete Structures”. Er. A K Sharma, Chief

New ICI Centre

th30 Centre at Siliguri

The function was presided over by Er. A K Sharma,

Chief Engineer, IBBMZ, CPWD, Siliguri, who also

gave the concluding remarks..

An Executive body of office bearers comprising of

Er. Shishir Bansal, Superintending Engineer,

Siliguri Central Circle, CPWD as Chairman, Er. G

K Bhaduri, consultant, Pioneer Engineering Pvt.

Ltd. as Hony. Secy. and Er. Pradeep Kumar,

Executive Engineer, Siliguri Central Division,

CPWD as Treasurer, was formed besides 6 other

members.

The programme was sponsored by M/S Pidilite

Industries Ltd. and was attended by 120 delegates.

Programme ended with cocktails and dinner.

Shishir Bansal

Chairman, ICI-NBC

Mr.Shishir Bansal, Chairman,ICI-NBC addressing the gathering

Er.A.K.Sharma, CE,CDO-CPWD making presentation

Section of the participantsChief Guest Mr.K.P.S.Ghuman, CE, MES addressing the gathering


News from Centres

Engineer, CDO, CPWD, New Delhi presented the

key note lecture on “ Causes of Deterioration of

Concrete” followed by presentation on 'Building

repairs' by Er. Atul Vaidya, Head of technical

Marketing-Pidilite Industries Ltd. and Er. Sudhir

Samant Head of training and application - Pidilite

Industries Ltd.

Brig. K P S Ghuman, Chief Engineer MES, Siliguri

Zone was the Chief Guest,


News from Centres

ICI-Ahmedabad Centre

Report on Lecture organized by ICI, Ahmedabad Centre in association with Ambuja Cement

ICI-Ahmedabad Centre organized a technical thlecture on 14 April, 2011 at Bhaikaka Hall,

Ahmedabad in association with Ambuja Cement,

GICEA and Institution of Engineers (Gujarat State

Centre) on “ Sustainable Cements and Concrete for

the Structures in the Climate Change Era”. The

lecture was delivered by Mr. P.K.Mehta (Professor

Emeritus in civil and Environmental Engineering,

University of California, Berkeley, USA). More than

two hundred and fifty professionals attended the

lecture.

Mr. Umesh Soni (Secretary- ICI, Ahmedabad Centre) introducing the Speaker

Mr. P. N. Jain (Chairman - ICI, Ahmedabad Centre) on the Dias with the Speaker

A section of the audience Mr. P.N. Jain,Chairman (Ahmedabad Centre) falicitating the Speaker


News from Centres

Dr.Mehta discussed in depth about Sustainability

in Construction industry with relevant data and

also presented outcomes of some scientific

research. He also discussed some case studies

using HVFAC technology. The lecture was

followed by question and answer session.

Participants interacted enthusiastically with the

speaker.

Earlier Mr. Bharat Modi. President-GICEA

welcomed the gathering. Mr. Mukesh Majithia,

VP-GICEA, Mr.Pradeep N. Jain, Chairman, ICI-

Ahmedabad Centre and Mr. Hitesh Barot,

Customer Support, Ambuja Cements Ltd.,

felicitated the speaker. Mr. Bakul Desai,

Secretary GICEA proposed vote of thanks.

P.N.JAIN Chairman ICI, Ahmedabad Centre

UMESH SONISecretary-ICI, Ahmedabad Centre

Dignitaries participated in the event

Plans are on the anvil to conduct several

competitions for student members at All India

Level and to award winners at the time of Annual

Event of ICI. Such events will provide immense

opportunity to you to exhibit your talents at the

National level and to interact with the experts from

the civil engineering field.

You will be hearing more from us soon.

R. RADHAKRISHNANSecretary General

Dear Student Members,

In response to your interest evoked in ICI we are

keen to extend more benefits for the students

community. In the recently held Governing

Council Meeting, decision has been taken to waive

the entrance fee of Rs.1000/- for you when you

apply for regular membership of ICI within an year

after your graduation. By this, you will be

recovering the entire annual fee you pay as a

student member.


Construction of Underpasses in Restricted Boundary Conditions

Jose Kurian

Chief Engineer, DTTDC, New Delhi.

Abstract

Introduction : Rapid growth in vehicular traffic necessitated the provision of grade separators like flyovers

and underpasses in New Delhi. This paper covers up case studies on four underpasses constructed with

different technologies to overcome the restrictions of various kinds in these sites.

SCOPE: First underpass constructed at Punjabi-Bagh crossing was placed 12 m below the ground as it was

the lowest component of four tier grade separator. Iron-ore layers were provided on the base slab as

counterweight to annul the high uplift pressure.

Second underpass at Madhuban-Chowk crossing had a restriction of already planned Metro-rail in transverse

direction. High uplift pressure on the base slab due to high water table was countered by permanent pre-

stressed soil anchors.

Third Underpass at Prembari-pul crossing had to be designed within the restricted passage available between

the running irrigation canal and Metro Rail corridor.

Fourth Underpass at Moolchand crossing was to be provided beneath the existing Flyover in transverse

direction. Innovative techniques were used to provide diaphragm walls beneath the flyover and in between

the piers of existing flyover.

Conclusion : Implementation of modern techniques and innovative designs is the solution to all complexities

arising in the design of infrastructures.

KEY WORDS: Uplift, Ironore, Soil Anchors, Voiders, Diaphragm wall, couplers

Introduction

New Delhi, the Capital city of India had been facing phenomenal growth of vehicular traffic without the

proportionate growth of infrastructure. It resulted in all sort of traffic congestions, increase in pollution

level, exponential rise in traveling time, increase in stress level, etc. etc. To limit these levels, it was decided

to construct grade separators on important corridors. The traffic flow system of Delhi is a Ring-Radial

pattern with two concentric Roads popularly known as Ring Road and Outer Ring Road. Radials to these

rings connect the traffic to the heart of Delhi. Ring Road and Outer Ring Road are the life lines for citizens of

Delhi. As one of the improvement measures, it was decided to start with the separation of grades at every

junction of these circular roads, so that crawling traffic can be made to run without any interruption on

these two corridors.

Kind of grade separators provided were flyovers, underpasses or in combination of clover leaves as per the

site requirement as well as feasibility. Though many of these locations were good enough to provide flyovers

or underpasses, but some of them were not friendly enough to design the structures without deploying extra

design skills. In general, kind of restrictions faced were limited site available, existence of structures

constructed in past, high water table causing high uplift pressures on foundation systems etc. etc.

This paper covers the underpasses constructed in this decade at four such locations where the boundary

conditions were not favorable and special design inputs, geometric as well as structural, were required to

make the structure feasible. Four such locations identified are Punjabi Bagh crossing on Ring Road,

Madhuban Chowk intersection on outer Ring Road, Prembari Pul crossing and Moolchand crossing, both

on Ring Road.

th16 ICI (KBC) Civil-Aid (Torsteel) Endowment Lecture


Punjabi Bagh Grade Separator

Location

Punjabi Bagh crossing is one of the important intersections on the Ring Road at its junction with Rohtak

Road in western part of Delhi. Here, the traffic volumes were very high along both the roads and therefore it

was essential to provide free traffic movement in both the directions.

Design Challenges

Number of residential and commercial buildings all around the crossing did not permit a full clover leaf.

Thus an innovative four tier grade separator was designed and provided for the first time in country. The

scheme provided for three levels for vehicular traffic and separate level for pedestrian movement. The three

levels for traffic movement are a flyover along Ring Road, an Underpass along Rohtak Road and a ground

level Rotary for turning traffic. Since the Underpass was the lowest component of the four tier grade

separator, it was provided at a depth of about 12 m below the natural ground level. Thus, the base slab was

subjected to huge uplift pressure of underground water. Figure 1 shows a cross sectional area of grade

separator with all components like flyover, rotary, pedestrian plaza and Underpass.

General Features

The six lane flyover is 828 m long consisting of 516 m stilt portion and 312 m embankment portion. There

are dual carriageways of 11.0 m each with 1.2 m central verge and RCC crash Barrier on either side. The

longitudinal gradient is 1 in 30 with a vertical clearance of 5.7 m and 2.5 per cent camber for drainage. A

Rotary of size 75 m x 50 m (25 m straight portion and semi circle of 50 m diameter on either side) has been

provided at ground level for turning traffic. A pedestrian plaza covering entire intersection on Ring Road and

Rohtak Road with four arms for entry / exit is another feature of this Project.

The 626 m long underpass along Rohtak Road below the surface level Rotary and pedestrian plaza caters for

two way traffic with 11 m wide dual carriageway, each providing 3 lanes. There is a vertical clearance of 5.5

m The central portion measuring 100 m of Underpass is covered to accommodate pedestrian plaza and

Rotary. The area on either side of this closed portion is open to sky laid at longitudinal slope of 1 in 30 with

two summit curves at extreme ends and two valley curves where open portions meet the covered portion.

Figure 2 gives a full view of Underpass along with other components after it was opened to traffic.

Figure 1 : Cross sectional area of Punjabi Bagh Grade Separator


Figure 2 : Underpass alongwith other components

Structural and Constructional Aspects

From structural design and construction considerations the underpass was divided in four zones as under.

Central Covered Portion (Zone-IV)

The central 100 m portion of underpass is a covered one and has two levels. The lower one is the main

underpass for vehicular traffic, while the upper one is pedestrian plaza. In the central covered portion, the

integrated structural system consisting of 800 mm thick, 18 m deep diaphragm walls alongside the

underpass with one central row of intermittent 800 mm thick and 28 m deep diaphragm wall. The

diaphragm walls, outer and central panels, have been horizontally connected at three levels, i.e. at base slab

of Underpass, floor and roof slab level of pedestrian plaza.

Trellis Portion (Zone-III)

In this portion 800 & 600 mm thick and upto 12 m deep diaphragm walls on the outer side and 600 mm dia.

pile-column at 2.5 m c/c in the central verge have been provided. The trellis have been provided as struts at

top, above clear headroom of 5.5 m connecting diaphragm walls and central piles to take care of lateral earth

pressure. 500 mm thick RCC base slab has been provided at bottom, below iron ore, connecting diaphragm

walls. Figure 3 shows the cross sectional area of underpass with trellis in Z III.

Open Portion with Diaphragm Wall (Zone-II)

In this portion 600 thick, 4.5 to 7.5 m deep diaphragm wall has been provided. A 150 mm thick RCC wall has

been provided alongside the diaphragm wall to share the lateral load while also acting as facia wall.

Open Portion with Retaining Wall (Zone-I)

For depth up to 3 m, open excavation with conventional retaining wall integral with the base slab was

adopted.

Figure 3 : Cross sectional area of underpass with trellis in Z III.


The uplift force due to buoyancy was a major factor in deciding the foundation system. The water table was

observed to be varying from 6 to 7 m below the ground level. For purpose of design, the buoyancy force in the

underpass was calculated considering water table at 3 m below of the original ground level and further to

ensure accuracy of the design assumptions during service life of the structure weep hole were provided in

the diaphragm wall at this level. The foundation system consisted of RCC base slab spanning between outer

diaphragm walls and thickness varied from 500 mm in Zone-II to 800 mm in Zone-IV.

Figure 4: Iron ore layers being laid over the base slab as counter weight

To counteract the uplift forces on base slab due to buoyancy, two alternatives were considered, one was with

the tension piles and the other was the use of dead weight to counter the uplift. Use of iron ore was preferred

over tension piles system for reliability, economy and speed of construction. The depth of iron ore layer over

base slab varied from 600 mm in Zone-II to 1300 mm in Zone III and 800 mm in Zone-IV.

Besides this, during excavation and construction of base slab till the laying of iron ore, the water level was

lowered and maintained at specified lower level through continuous operation of vacuum pump operated

well point dewatering system. Figure 4 shows the iron ore layers being added over the base slab to counter

the uplift pressure.

Madhuban Chowk Underpass

Location

Madhuban Chowk is one of the important intersections on the Outer Ring Road at its junction with road

designated as Road No. 41. Here, Delhi Metro Rail Corporation (DMRC) had already planned an overhead

corridor in transverse direction. To plan a flyover over and above the metro line with all mandatory overhead

clearances was not only a costly solution, but visually unpleasing hindering the sky line. This had caused

the restriction in providing a grade separator for vehicular traffic travelling along the outer ring road. Thus,

decision was taken to provide an Underpass along the outer Ring Road.

Design Challenges

Incidentally, during the Planning stage, when soil investigation was carried out, the underground water

table was found at just 2 m below the ground level, while the construction of underpass had required going

as deep as 7 m. Thus the deepest structural portion of the underpass i.e. the bottom of the base slab was

subjected to pressure of 5m high water column which was required to by countered. One conventional

solution was to provide tension plies or to add weight to the base slab by adding some heavier material like

concrete itself or a metallic ore. But providing any additional layer of any material would have required

pushing the slab further down. This in consequence would have further increased the uplift pressure on

base slab. In the instant case, the uplift pressure was already too high to have a reasonable thickness of

overweight. Other alternative of providing tension piles is also not a healthy solution in water bound area. In

the present circumstances, the feasible solution was to anchor the slab by means of ground anchors.


General Features

The 555 m long Underpass caters for two way traffic, with 9 m wide dual carriageway, each providing 3

lanes. The central portion of the Underpass is covered with 1200 mm thick pre-stressed voided slab with a

clearance of 5.3 m for the through traffic. The length of this covered corridor is 60 m and is horizontal in

longitudinal direction, but with a camber of 2.5 % for draining out the rain water.

Fig. 5. Typical Cross Section of Underpass through the covered portion

The slab at top caters for cross traffic at grade. The area on either side of this closed portion is open to sky

laid at longitudinal slope of 1 in 30 with two summit curves at extreme ends and two valley curves where

open portions meet the covered portion. One arm of the Underpass is in curve with 4 % super-elevation and

remaining is provided with a normal camber of 2.5 % to drain out the rain water. Fig. 5 shows a section of

Underpass in covered portion.


The construction of the Underpass was taken up from top to bottom. The side retaining walls were designed

and constructed as Diaphragm wall having thickness 800mm at deep portions and 600 mm at shallow

portions. As a part of top to bottom construction, first of all 800 mm thick diaphragm wall panels of closed

portion were cast followed by the casting of slab at the required level on the virgin soil only. After casting of

all diaphragm wall panels on both sides of Underpass, the excavation was carried out to remove the earth.

Since the water table in the Underpass area was too high, dewatering wells were provided at close intervals

to keep the water table low and ease out the construction activities like excavation, waterproofing, laying of

base slab and installation of anchors including pre-stressing and grouting etc. After successful installation

of the anchors, remaining works like PFRC wearing course, cladding to diaphragm wall with decorative

finish, crash barriers, planters etc. were executed and traffic was allowed through the Underpass.

General layout of anchors

Total 990 nos. soil anchors were provided in the area, wherever the slab was subjected to uplift pressure.

For the convenience of execution, all the anchors in complete underpass area were made of 40 T capacity,

but depending upon the uplift pressure expected, the spacing between the anchors had been adjusted. In

the shallow area, the spacing had been kept as 3.5 m centre to centre in both directions and when the depth

is increased to 4 m, the spacing was reduced to 2.5 m centre to centre in both the directions.


Figure 6 : Details of the Anchor (L-Section and Cross Sections)

Design capacity of soil anchor

Initially Performance Test, Proof Test and Creep Test were conducted for 40 T capacity on 3 anchors in

project area in accordance with the FIP recommendations for the design and construction of prestressed

concrete ground anchors. The parameters adopted were bonded length of anchor as 10m, un-bonded length

of anchor as 10m and the dia of bore-hole as 150mm. Figure 6 shows the vertical section and cross section of

the typical anchor.

Installation and Prestressing of anchors

RCC Base slab (800 mm thick in the deep portion and 600 mm thick in shallow portion) was cast prior to the

installation of the anchors. While the base slab was casted, a through hole of 300 mm dia. was created at the

anchor locations and after the concrete was set and gained sufficient strength, 150 mm Ø bore in the soil

beneath the base slab was drilled using rotary drilling machine. As one of the corrosion protection measures

adopted to protect the strands, the anchors were grouted internally as well as externally with cement grout.

After grouting, the anchor was prestressed after a minimum of 21 days. The pressure grouting, injection-

grouting was carried out to effectively seal any loose pockets and eliminate the possibility of water oozing. All

anchorages were epoxy painted and covered with grout after stressing. The recess was then concreted with

non-shrink grout. Figure 7 shows the hydraulic rig C-6 in operating and Figure 8 shows the anchors

installed in position.


Figure 7 : C-6 Hydraulic Rig in operation Figure 8 : Anchors installed in position

Fig. 9. A view of Underpass in operation

The base slab was overlaid by 75 mm thick poly-fiber reinforced concrete wearing course as a protection

layer to soil anchors and smooth riding surface. Fig. 9 shows a view of Underpass after the same was opened

to traffic.

Prem Bari Underpass

Location

Prembari Pul crossing is one of the important intersections on the Ring Road at its junction with road

designated as Road No. 37 (Raja Nahar Singh Marg). To facilitate the smooth movement of traffic, it was

decided to provide a grade separator at this intersection. Various options considered were the cloverleaves

interchange option which was not feasible due to space restrictions. The flyover option though good but was

not possible due to presence of DMRC structure on the western side. Considering the above constraints,

Underpass along Ring Road was the only feasible option to minimize bottlenecks for Ring Road traffic.

Design Challenges

Delhi Metro Rail Corporation (DMRC) had already constructed elevated corridor on its western side, while

Yamuna Irrigation Canal was existing on its eastern side. Due to these limitations on both the sides, the

Underpass was to be designed within the limited length of 255 m. This had caused the restriction in

providing a grade separator along the ring road. For a normal underpass with a covered portion of 35 m,

length of the underpass required is around 425 m keeping 1 in 25 as maximum permitted gradient and 30 m

long summit/valley curves. Figure 10 shows a view having the constraints of Yamuna canal bridge and

DMRC structure restricting the length of Underpass.


Figure 10 : Underpass plan showing Yamuna Canal and DMRC Structure on two ends

The Underpass is constructed by partially raising the intersection from the existing ground level up to 3.5 m

and partially lowering the Ring Road to a maximum of 2.5 m from the current levels.

General Features

The 255 m long Underpass caters for two way traffic with 9.2 m wide dual carriageway, each providing 3

lanes. The central portion of the Underpass having a length of 35 m is covered with 1200 mm thick

prestressed voided slab which caters for cross traffic at grade. The area on either side of this closed portion is

open to sky laid at longitudinal slope of 1 in 25 with two summit curves at extreme ends and two valley

curves where open portions meet the covered portion. Figure 11 shows a section of Underpass in covered

portion.

Fig. 11. Typical Cross Section of Underpass through the covered portion





portion were cast followed by raising the wall as the level of the central portion of the underpass was

designed as raised from normal ground level. Thereafter the slab was cast and after maturity of slab

concrete, the excavation was carried out to remove the earth followed by cosmetic works like 125 mm thick

PFRC wearing course, cladding to diaphragm wall, crash barriers, planters etc. Figure 12 shows a view of

Underpass after the same was opened to traffic.


Figure 12 : A view of Underpass in operation

Moolchand Underpass

Location

Underpass at Moolchand interchange is one of the important intersections on the Ring Road at its junction

with Lala Lajpat Rai road in southern part of Delhi. Here, Delhi PWD had already constructed an overhead

corridor in transverse direction. It was not feasible to plan a flyover over and above the existing flyover. This

had caused the restriction in providing a grade separator for vehicular traffic travelling along the outer ring

road. Thus, decision was taken to provide an Underpass along the outer Ring Road.

General Features

422 m long Underpass caters for two way traffic with 9.15 m wide dual carriageway, each providing 3 lanes.

The central portion of the Underpass is covered with 1000 mm thick pre-stressed voided slab in M45 grade

concrete with a clearance of 5.3 m for the through traffic. The length of this covered corridor is 72 m and is

horizontal in longitudinal direction, but with a camber of 2.5 % for draining out the rain water. The slab at

top caters for cross traffic at grade.

Figure 13 : Typical cross-section of Underpass showing flyover in transverse direction

The area on either side of this closed portion is open to sky laid at longitudinal slope of 1 in 30 with two

summit curves at extreme ends and two valley curves where open portions meet the covered portion. Figure

13 shows a section of Underpass in covered portion.

Design Challenges

To provide an Underpass under the existing flyover was a big challenge. The first challenge was to restrict

the Underpass within the obligatory span of the flyover and saving its Piers and foundations from any kind

of settlement while laying the foundation of Underpass. Next challenge was to provide diaphragm wall in the

area beneath the flyover due to restrictions in height making impossible for the normal rig to operate in this

area.






portion were cast. For the construction of diaphragm wall at central 24m stretch beneath the flyover, having

limited headroom available for works (which is approx. 5.2 m), special rig (RH6) and special tripod for

reinforcement cage lowering were deployed. After construction of guide wall, the RH6 was erected. Rotary

drill of 800 mm dia was attached to the rig. Mud reservoir was filled up and trenching was commenced with

drill. Drill was rotated in the controlled head of bentonite mud. After predetermined drilling time, the drilled

muck was taken out with Reverse Circulation method. Figure 14 shows a view of the machinery deployed

for providing diaphragm wall under the flyover area and the earth slurry being flushed out.

Figure 14 : Working system of RH-6 Figure 15 : Coupled Reinforcement bars

Fabricating a reinforcement cage of 20 m height and then inserting in the vertical slit of diaphragm wall was

another challenging task. So, the reinforcement cages were fabricated in parts of 4 m height each and each

of them were joined by means of mechanical couplers. Each part of the cage inserted and kept on hold at

specific height for making a connection with next cage by mechanical coupler. The special tripod hoisted the

cage and then lowered it in to the complete trench. By this process, the total height of the reinforcement cage

was completed and inserted. Figure 15 shows the reinforcement bars connected by means of mechanical

couplers. After lowering the re-inforcement cage, trimie pipe was lowered in pieces (connected while

lowering) for full depth of trench, with the help of special tripod. Concreting was done with tremie method.

Thereafter the slab was cast and only after maturity of slab concrete, the excavation was carried out to

remove the earth. Remaining construction activities like excavation, laying of 300 mm thick RCC base slab

and PFRC wearing course, cladding to diaphragm wall with decorative finish, crash barriers, planters etc.

were executed and traffic was allowed through the Underpass. Fig. 16 shows a view of the Underpass after

opening to traffic.

Figure 16 : A view of Underpass with flyover on top


Monitoring of Adjacent Structures

The diaphragm wall and adjacent structures were monitored for settlement and lateral displacement of the

surrounding soils during and after the construction of the wall. The settlement of the existing foundations

was measured by taking levels using leveling instruments. The displacement of the surrounding soils was

monitored using inclinometers installed in between the diaphragm wall and adjacent structures.

Conclusion

Designing of any structure may not be convenient at every location. Constraints do exist, but a feasible

solution is always available. It requires a good planning after considering the various options to overcome

any constraint. The four Underpasses discussed in this paper had some kind of limitations. Base slab of

Punjabi Bagh Underpass being too deep, had to bear a good amount of uplift pressure which was overcome

by adding counter weight in the form of iron ore layer on the base slab. In Madhuban Chowk Underpass,

water table being too high created high uplift pressure on base slab, which was annulled by providing 20 m

deep soil anchors at a spacing of 2.5 to 3.5 m c/c. Prembari Underpass had limiting length due to

permanent structure on eastern as well as western side and permissible gradients were achieved by raising

the height of Underpass at its centre. Moolchand Underpass was to be constructed under an existing flyover

and between the piers of obligatory span, thus innovative methods were used to provide diaphragm wall and

simultaneously protecting the foundation of Flyover from any kind of damages.

Acknowledgements

The authors are thankful to Er. Pradeep Garg, Executive Engineer, Punjabi Bagh Grade Separator Project,

Er. B B Badhwa, Executive Engineer, Prembari Pul Underpass Project and Er. K C Pant, Executive

Engineer, Moolchand intersection interchange Project who have provided the necessary information,

relevant data and project photographs, without which it was not possible to compete the paper in the

present shape.

References

1. Narayan D., Agrawal K. N., Chugh B.K. and Rustagi S.K., “Multi level grade separator at Ring Road”,

Journal of the Indian Roads Congress Vol. 64-3, December 2003, pp.453-479.

2. Bansal S., Gupta V., “Use of prestressed soil anchors in the construction of an Underpass in high water

table zone”, Conference Document of National Seminar on Innovative Load Transfer devices and th thFoundations, organized by IIBE Delhi State Centre, 13 and 14 January, 2006, pp.19-35

To all ICI Centres

Please forward us the audited accounts statement for the financial year 2010-2011 before the end of June

2011 without fail as it is mandatory to finalise the audited accounts of the headquarters.

R. RADHAKRISHNANSecretary General


Self Compacting Concrete for the Tallest Building in India*

S. A. ReddiFellow, Indian National Academy of Engineering

Abstract

The paper presents important aspects of the M80 grade self compacting used in the construction of the

columns of Palais Royale, a LEED-platinum-rated green residential building, about 320m tall, under

construction in downtown Mumbai, India.

Introduction

Conventional concrete casting relies on compaction to ensure adequate strength and durability. Insufficient

compaction leads to voids, which reduces compressive strength, strongly influences the natural physical

and chemical protection of embedded steel reinforcement afforded by concrete. Concrete is compacted

manually using vibrators, often operated by untrained labour with insufficient supervision, overall

durability is reduced. Inadequate compaction affects the material but also have health and safety and

environmental risks with operators subjected to 'white finger syndrome' and high levels of noise. Self Compacting Concrete (SCC) was developed in Japan as a quality assurance concept and over the last two

decades is preferred by many countries; it fills into forms and around congested reinforcement without

vibration; fluidity is realised by proper mix, increased fine aggregates, addition of mineral admixtures, new

generation of polymer superplasticizers and better quality assurance.

SCC was introduced in India in the Nineties. The reconstruction of the Reactor dome of the Kaiga Atomic

Power Project is noted for the introduction of high performance concrete Grade M-60. During the

construction of Units 3 & 4 at Kaiga, SCC was introduced for heavily reinforced components; about

5000cu.m. of SCC was successfully laid. This was followed by a number of projects across India. The

present paper presents salient aspects of the M80 grade SCC for the columns of Palais Royale, a platinum

rated green residential building, about 320m tall, under construction in downtown Mumbai. About

50000cu.m. of SCC has already been realised.

Benefits of SCC

! Increased productivity levels leading to shorter concrete construction time

! Lower concrete construction costs

! Improved working environment

! Improvement in environmental loadings

! Improved in situ concrete quality in difficult casting conditions

! Improved surface quality

Disadvantages of SCC

! Increased material costs, especially for admixtures and fine aggregates

! Increased formwork costs due to possibly higher formwork pressures

! Increased technical expertise required to develop and control mixes

! Increased variability in workability

! Stringent quality control requirements

! Reduced hardened properties modulus of elasticity

! Increased risk and uncertainty associated with the use of a new product

Selected Seminar Paper

* Paper presented ACECON 2010 an Asian Conference on 'Ecstacy in Concrete' organised by Indian

Concrete Institute at Chennai in December 2010


Brief Description Of Palais Royale, Mumbai

A 320m tall luxury residential tower is under construction in downtown Mumbai. The structural

components are of high strength concrete. The reinforced concrete columns were earlier designed with M60

grade concrete. Based on the author's intervention, the developers agreed to increase the concrete strength

to M80. This resulted in substantial reduction in the column cross section and reinforcement. There was a

further reduction with the use of Fe 500 grade reinforcement bars. The building is founded on a reinforced

concrete raft.

Residential flats start at a height of about 80m. The space below is utilized for amenities car parks, sports

facilities, swimming pools, Building Management System (BMS) facilities etc. The floor-to-ceiling height is

typically 4.2m, doubled in the case of villas at the top.

Figure 1: Photographs of the Progress in the Construction of Palais Royale, and a Computer Generated Skeletal View

Wind tunnel tests were conducted in Canada. Special precautions against fire and firefighting measures

have been incorporated. A sophisticated Building Management System is planned to be in place. High

Strength Self Compacting Concrete, grade M80 is used for all the columns.

Palais Royale design involves a podium that houses functional spaces which require an unobstructed

spatial layout in order to give a more impressive view. For the upper structure used as residential units,

more economical shorter span design is used for columns. The layout of the podium structure uses

regularly spaced columns in longer span design. The prestressed concrete transfer girders are located

between 70m and 80m level. These are specifically designed as support for columns between the lower floors

(used for car parking and as amenity spaces) and the upper floors, the residential spaces. Joining these two

areas, the transfer girder has been designed with a width of 1.5m and a record depth of 9m. The girders are

prestressed in two directions. The tendon ducts in addition to heavily congested reinforcement necessitated

use of SCC M60 concrete for the transfer girders.

The architects and structural engineers are from Mumbai, with proof checking done by an American

consultant. There are separate consultants for the Services, Electrical, Acoustic, Lift, Environment, Fire,

Windows, Façade, Waterproofing, Waste Management, Renewable Energy, Vaastu, etc.

Materials

The workability requirements for SCC are typically defined in terms of three properties: passing ability,

filling ability, and segregation resistance. Filling ability describes the ability of concrete to flow under its own

mass and completely fill formwork. Passing ability describes the ability of concrete to flow through confined

conditions, such as the narrow openings between reinforcement bars. Segregation resistance describes the

ability of concrete to remain uniform in terms of composition during placement and until setting filling of

formwork with a liquid suspension requires workability performance described as follows:


0 Filling ability: Complete filling of formwork and encapsulation of reinforcement and inserts.

Substantial horizontal and vertical flow of the concrete within the formwork maintains

homogeneity.

0 Passing ability: passing of obstacles such as narrow sections of the formwork, closely spaced

reinforcement etc. without blocking caused by interlocking of aggregate particles.

0 Resistance to segregation: Maintaining of homogeneity throughout mixing and during

transportation and casting.

SCC is highly sensitive to changes in material properties and proportions and, requires increased quality

control. The consequences of deviations in workability are more significant for SCC. A slight change in water

content may have minimal effect on conventionally placed concrete but lead to severe segregation and

rejected work in SCC. Only ordinary portland cement (OPC) is used, as mineral admixtures are added

separately in the batching plant. After extensive trials, OPC from Ultratech has been chosen. Processed fly

ash retains spherical shape and reduces water demand. The small particle size increases the spread of the

particle distribution, also improves workability. Processed fly ash from Dirk India, Nashik, is used.

Initially condensed silica fume was used; subsequently, reliable sources for metakaolin have been identified

and are used. Silica fume improves concrete rheology and enhances stability when used at low dosages, i.e.,

4-6% by replacement of cement, but can have detrimental effects on rheology at higher dosages. Silica fume

is expensive (Rs. 25 Rs. 30 / kg) and the quantity is restricted just to satisfy the properties. More favourable

constructability-related properties are derived with metakaolin. With average particle size 20- 30 times

larger than silica fume, the water demand with metakaolin is lower. The result is a high-strength concrete

having improved workability, finishability, and a reduced tendency for surface dehydration and plastic

cracking. Being lighter in color than silica fume, metakaolin will not darken the color of the paste or mortar.

Metakaolin is a highly reactive aluminosilicate, capable of producing mechanical and durability properties

similar to silica fume. Unlike fly ash, blast-furnace slag and silica fume, which are by-products of major

industrial processes, metakaolin is a specifically manufactured mineral admixture. Kaolin clay or China

clay is used as the raw material for its manufacture. It is a fine, white mineral, primarily of hydrated

aluminium disilicate. Extensive trials were conducted before switching over to metakaolin. Due to higher

particle size, metakaolin requires less amount of admixture than silica fume for the same slump flow. It has

a creamier texture, generates less bleed water and has better finishability than concrete with silica fume.

Chemical Admixtures

PCE based admixtures are imported. After trials, three alternative sources were identified. Fresh trial mixes

were conducted before changing the brand of PCE based admixtures. Viscosity modifiers (VMA) are added to

increase the resistance to segregation. They are high molecular weight soluble polymers, which in aqueous

medium have increased viscosity because of their interaction with water. The use of VMA is desirable but

not essential.

Aggregates

Natural aggregates and/or crushed aggregates may be used. In Palais Royale, 20mm maximum size

crushed aggregates are used for columns up to 70m; reduced to 10mm for columns above 70m. Gravel is not

used, due to erroneous perceptions. The optimum gradation of fine aggregate for high-strength concrete is

determined more by its effect on water demand than on particle packing. SCC contains high volumes of

cementitious sized material. As a result, fine sands, are less suited for SCC due to the sticky consistency

that may result. Coarse sands are desirable in SCC. The grading of fine aggregates is less critical in SCC

mixtures. Locally available sand could not match the quality requirements for SCC since the silt content is

very high. Facilities for washing in Mumbai are expensive. Hence, fine aggregate has been obtained from

Gujarat. Use of locally manufactured sand is now under consideration.

Trial mixes for M80 SCC

Large number of trial mixes was conducted with various combinations. Fresh and hardened properties

achieved in the laboratory are sometimes different from those achieved in full-scale production.

Therefore, trial batches were produced in the site batching plant. The E-value was tested, and found to

be similar to that of ordinary high strength concrete.


Post-28-day designated acceptance ages

The selection of materials and mix proportions for high-strength SCC may be based on a designated age of

56 or 90 days rather than the traditional 28 days. For high rise buildings, loading conditions are such that

the design strengths are not needed until much later. At Palais Royale, a large number of extra cubes are

cast and tested for 56 and 90 days. Results are used for accepting concrete of occasionally lower 28 day

strength and for possible revision of structural design of columns based on 56 day strength, a common

practice in the USA. Based on statistical evaluation of works test results, the approved mix may qualify for

M90 / M100. Taking advantage of post-28-day strength gain, choosing a designated age of 56 or 90 days

allows for a reduction in the paste content of the mix, which can be highly beneficial in reducing total

shrinkage and improving long-term durability potential.

Handling of constituent materials

Materials are stored in the same manner as for production of vibrated concrete; in ground bins, silos, and

tanks for admixtures. Consistency of raw materials is controlled more frequently. Best practices are applied

on the maintenance of stockpiles of materials, i.e. moisture contents, free drainage, cleanness, and

prevention of segregation.

Production of SCC

Two 45 cu.m. batching plants are installed at site as the RMC supplies were not forthcoming for M80 SCC.

Trials were conducted to ensure complete mixing. A minimum of one minute mixing time was decided upon,

against the standard mixing time of 30 seconds. Considering the uncertainties involved in transportation,

feeding the concrete pump, laying the concrete pipelines and possible placement delays, it was decided to

allow for about one hour of delay between production of concrete and placement. The European Guidelines

provide for three levels of slump flow: SF1 (550-650 mm) appropriate for slightly reinforced structures; SF2

(650-750mm) suitable for normal applications and SF3 (760-850 mm) for very congested structures.SF2

should have been used for this project. However, a slump flow of about 800mm was adopted to cater to

uncertainties.

Constructability Properties

Constructability refers to the properties that are necessary for the mix to be produced, delivered, placed,

consolidated, finished, and cured, to achieve the required mechanical and durability properties. They

include slump flow, workability retention time, Pumpability, Finishability, and setting time. Work was

streamlined over a period of time after great deal of conflicts and dialogue between the production and

execution teams.

Transportation and Placement of SCC

Six cu.m. capacity truck mixers and concrete pumps capable of pumping concrete to the full height in one

stage are provided. Tests are conducted for each load of concrete discharged by the transit mixer: 1) Slump

flow test, 2) V-Funnel Flow Time, 3) L-Box (passing ability), 4) T-500. The concrete is distributed through

pipes supported on Self Climbing Placer Booms. The columns and shear walls are jump-formed. The form

panels use a unique patented system, scratch-proof and capable of unlimited use, realizing smooth surface

not requiring further treatment or plastering. The mix is designed for high early strength to enable removal

of formwork (with props left under) in 24 hours of concreting. A four day time cycle per floor is aimed at.

Modulus of Elasticity

The modulus of elasticity of conventional-strength concrete increases proportionally to the square root of

the compressive strength. While many empirical equations for predicting modulus of elasticity are

proposed, few equations predict the E-value of high strength SCC as accurately as they do for conventional-

strength concrete. A series of trials were conducted at site, confirmed by other laboratories, and the results

fed to the structural designer.


SCC Robustness

SCC does not change from truck mixer to formwork; no one on the site can add water and absence of

vibration does not affect the homogeneity of the mix. This is an extra robustness that standard concrete can

never reach. Slump flow loss occurs between the batching plant and feeding into the concrete pump due to

variations in the input, batching errors etc. Any attempt to redose admixtures at the delivery end is resisted.

In extreme cases, the particular batch is rejected. There has been conflicting requirements as viewed by the

engineer in charge of placement and the engineer in charge of concrete production. While the field engineer

generally asks for higher slump flow values, the concrete production engineer sticks to the value specified.

Increasing the slump flow generally results in segregation of concrete, pipeline choke etc.

Homogeneity in the structure is higher than using normal concrete; specimens are really representative.

These conditions allow designers to choose higher loads for the material with benefits in dimensions, weight

and costs. Complicated geometries become now easy to fill, such as sharp corners, inserts as boxes or

windows in the walls, thin sections, areas with no access or with congested reinforcement. SCC is a state of

fresh concrete; hardened all characteristics are the same as normal concrete of similar strength.

3.11 Permeability

There is a reduction in permeability due to the high content of fines in the mix. Tests carried out with

comparison to standard concrete mixes having the same water/cement ratios gave impressive results.

Water penetration is reduced to about one third; penetration depth increases more slowly. This may be due

to the presence of fines particles to maintain a compact structure. So, SCC can guarantee a reduced

permeability. Spread between average and maximum penetration depth is reduced in SCC.

3.12 Grade of Concrete

The columns of Palais Royale were initially designed using M60 concrete. After considering the highly

congested reinforcement, it was decided to use M80 self compacting concrete. The designs were duly

revised, resulting in substantial reduction in column sizes and consequent increase in carpet area. In India,

adaptation of SCC for higher grades of concrete is still in its infancy; some building and bridge projects have

sporadically used high strength SCC. M80 Grade SCC has probably been used for the first time in India at

Palais Royale in Mumbai. The beams and slabs are in 60 MPa grade concrete.

Figure 2: Casting SCC - a one-man operation Figure 3: SCC flowability, passability and stability

Workability Retention

Workability retention and setting time are different properties, evaluated separately. Workability retention

depends on admixture type and dosage, mix proportions, concrete temperature, weather conditions etc.

Workability retention should be tailored to application because excessive workability retention is

unnecessary and may increase formwork pressure and segregation.


Setting Time, Bleeding

The setting time of SCC is typically similar to that of conventionally placed concrete. However, due to the use

of chemical admixtures and mineral admixtures in SCC, setting time could increase or decrease based on

mix proportions. Polycarboxylate-based HRWRAs generally result in less of a delay in setting time. Given its

low water content and high viscosity, SCC typically exhibits minimal surface bleeding. In particular, the use

of fine filler materials and viscosity modifying admixtures increases the ability of the paste to retain water

and result in reduced bleeding.

Mix proportioning

Mix proportioning was primarily based on trial mixes; guidance drawn from Japanese and European

publications, experiences, recommendations for SCC, JSCE Manual for production & placement of SCC,

Guidelines for mix design of SCC, by Danish Technological Institute (2008) and European Guidelines for

SCC, EFNARC 2005

Concrete mix M80 adopted at Palais Royale:

Cement 400 kg

Fly Ash 200 kg

Micro Silica/ Metakaolin 40 kg

Sand 968 kg

Coarse Aggregate 676 kg

Admixture 4-5 kg

Viscosity Modifier 0.7 kg

Minor adjustments have been carried out from time to time based on variation in properties of materials and

workability requirements.

Sensitivity to variations

SCC is more sensitive to fluctuations in the total water content than vibrated concrete. Fluctuations in

aggregate gradings and moisture contents have dramatic influence on the stability and fluidity of the

concrete mix. The total water content consists of mixing water and water from the surface moisture of

aggregates. Surface moisture of aggregates are measured by either moisture probes (sensors) or manual

drying tests. Moisture probes can offer real-time result, although accuracy of the results may depend on the

position of the probe in the production chain. However, the maintenance cost can be high. Manual drying

tests are accurate, simple and reliable but take time and cannot offer real time results. SCC is more sensitive

to significant deviations of material quantities. Larger load sizes of concrete lead to better consistency, avoid

batching of small loads of SCC. Batching equipment should be regularly checked for the accuracy. A special

attention should be paid to the accuracy of liquid admixture dispensing/dosing equipment.

Figure 4: Moisture sensor for sand moisture Figure 5: Pressure transducers, flush with form panels


Formwork

Special formwork imported from Germany is used for columns, beams and slabs. It consists of modular

panels, capable of being combined to form any shape and size. Each panel is light in weight, can be handled

by one technician. The panels are assembled with the help of spring clips and wedges. No bolts and nuts are

used. The formwork facing is similar to plywood and is made of patented synthetic material. The formwork is

capable of unlimited reuses provided they are handled carefully. The choice was based on the excellent

performance during the construction of the tallest building in the world, Burj Khalifa in Dubai.

Figure 6: Patented Formwork

The patented formwork is water-tight, avoids leak of slurry from the SCC resulting in honey-comb free

concrete. The use of foamed plastic sealing strip or moisture curing gunned silicone rubber provides

effective means of sealing joints. Pumping SCC into the form work from underneath is beneficial when high

demands of aesthetics are of importance. The problem with pores and pot-holes also tends to be less when

the concrete has been fed from underneath through valves. Vertical formwork is filled by pumps or crane

skips. . Flat and shallow formwork such as slab and decks are filled from above.

Figure 7: Column Reinforcement Figure 8: SCC Column Surface


Form work pressures

Reports on form pressure measurements using SCC indicate that a pressure equal or nearly equal to

hydrostatic values will develop at casting rates over 3-5 meters per hour. There is need for controlling the

rate of pour. For SCC, entrapped air is forced out by the moving concrete inside the formwork. SCC should

always be given the possibility to flow for at least a certain distance. Casting all along the element should be

avoided.

Several experiments were conducted and actual formwork pressure under field conditions was monitored.

Though many authorities specify formwork be designed for full hydrostatic pressure, field experiments

indicated pressures higher than those assumed for normal concrete, but lower than hydrostatic pressure.

The rate of pour of the column concrete was regulated to ensure lower concrete pressures. The special

formwork, already procured from MEWA, Germany, did not cater to pumping from bottom up and higher

concrete pressures.

Quality Assurance

Experimental investigations relating to SCC production were aimed at optimizing the process-related

parameters for quality assurance. In this process, mixer-specific details could be defined relating to the

following parameters:

4 dosing sequence

4 dosing accuracy

4 mixing effectiveness

4 mixing time

4 mixing speed

Longer mixing times are required for the production of SCC than for standard concretes. Efficient mixing

times can be achieved by varying both mixing tools and mixing speed.

At Palais Royale a full fledged concrete technology unit has been established, with the necessary testing

equipment and highly qualified staff under the direction of a full time expert, assisted by a PhD concrete

technologist. Concrete mixes are revised from time to time based on the variations in the constituent

materials including admixtures.

E Values assumed in the design are verified from time to time by actual experiments. Before commencement

of SCC pours in columns, a series of mock ups were conducted, in order to verify segregation resistance,

temperature variations between the core and the surface etc. A number of cores were taken and examined.

Necessary corrective action in the method of placement, permissible free fall of concrete etc. has been taken,

based on the mock ups.

Figure 9: Casting of wall with two methods (Gravity filling and pressure)


Curing

SCC is more susceptible to plastic shrinkage cracking than conventional concrete because of the lack of

bleed water and the he high paste volume. Due to the greater susceptibility to plastic shrinkage cracking,

curing is started immediately after casting regardless of weather conditions. White pigmented curing

compounds are used in Palais Royale. SCC mixes contain higher amount of fines including mineral

admixtures. Thus, there is very little or no bleeding and the concrete will sometimes be more sensitive to

plastic shrinkage cracking. The fresh concrete surface is protected from weather by polythene sheets. Water

curing is started at the earliest.

Working environment

The improvements in working environment when using SCC are substantial on the individuals, on the

society as well as on the technical and economical level. The cost of the society for health care is reduced as

well as the company costs for sick leave, early retirement etc. Legal limitation on time when persons are

subjected to high noise will not be decisive for the length of a working day. It also results in the elimination of

blood circulation disturbance due to handheld vibrators and the strongly reduced noise level. The reduction

of physical loading from lifting equipment and moving concrete is important as well as the increased safety

due to elimination of cables, transformers, vibrators on the workplace and improved verbal communication

between workers. The reduction of the overall noise from the workplace is creating fewer disturbances to

building site neighbours

Concreting

SCC is preferably pumped from below; the pipeline is connected through special valves. However, this could

not be done at Palais Royale and concreting was placed from above. The elimination of manual compaction

makes very high casting rates possible which, in combination with the high flowability, might cause high

formwork pressures. If the concrete is so designed, thixotropic effects can significantly reduce the formwork

pressure. SCC is a complex material with several sensitive interactions between the constituent materials.

Compared to vibrated concrete SCC requires more knowledge, competence and skill of personnel, more

closely controlled properties of the constituent materials and greater care in production and delivery. The

technology also requires greater skill and care in the casting operation. These call for increased focus on

training personnel and on quality assurance issues.

Finishing

Delaying the placement of high-strength SCC results in loss of workability over time, therefore deliveries of

the concrete to the site are scheduled so it will be placed promptly upon arrival. Coordination of delivery

between the batch plant and the placing team is ensured. Yet there are occasions when placement is

delayed, resulting in rapid loss of slump flow, difficulties in finishing operations etc. Finishing operations

are more difficult for SCC due to the thixotropic, sometimes sticky behaviour. Absence of bleeding makes it

even more difficult and finishing operations are related to setting time of the mix in actual conditions.

Appropriate field trials are performed in advance to improve planning and timing of finishing. The

characteristics of the SCC mix, and the skill and timing of the finishers during placement affect the quality

of the surface of slab cast. Conventional tools and ways to finish the upper surface are used This operation

takes a little longer in comparison with the finishing of conventional vibrated concrete. Excellent surface

finish is obtained while using SCC due to excellent flow characteristics, higher percentage of fine aggregate

plus mineral admixtures

Temperature of fresh concrete

Due to the massive column sizes in spite of M80 grade concrete, it was decided to restrict the temperature of

fresh concrete to maximum 30ºC. This has been achieved by adopting measures for hot weather concrete

including use of chilled water for mixing, shading over aggregate stockpiles, etc.


SCC Issues Addressed

Despite refinements adopted at Palais Royale, several issues are yet to be resolved:

4 Workability: slump flow requirements

4 Free fall of concrete vs segregation

4 Slump loss - production to placement

4 Maximum dosage of PC based admixtures

4 Use of manufactured sand

4 Maximum size of coarse aggregate

4 Formwork pressures: Pressure of Fresh SCC on Vertical Formwork

4 In production from March 2008; 28 days work strength range : 90 - 100 MPa

4 Standard deviation of works cubes ~ 3 MPa

4 Slump flow: insistence on a higher slump flow by field staff.

4 Coarse aggregates: consistency of supply

4 Admixtures: variable quality by same supplier

Credits

Mr. Vikas Kasliwal, the Chief Executive of the Developer, has been responsible for many bold initiatives

including the use of M80 grade SCC.

Testing Fresh Concrete

Slump flow values are tested for each truck mixer load, first as the concrete is discharged from the batching

plant, and then as the concrete is fed into the pump. Any abnormal loss of slump flow is investigated in each

case and corrective action taken by the QA personnel. The variability is reduced in majority of the cases by

coordinating the time of loading; mixes are loaded into the truck mixer in coordination with the placement

crew. In extreme cases of delay, occasionally the mix is rejected.

Testing Hardened Concrete

Works test cubes 150mm size are cast as per IS Standard method except for compaction. Cubes are filled for

full depth of the mould and finished, without any tamping/vibration, and tested at 28 days for compressive

strength. Additional cubes are routinely tested at 56 and 90 days to evaluate strength increase with time.

Based on evaluation over a period of more than a year, it was observed that the M80 concrete used for

columns had strengths in excess of M90 at 56 days and M100 at 90 days. Efforts are on to redesign the

columns above 100 m, taking advantage of higher actual strengths obtained.

Mock up trials

As such high strength SCC is being used for the first time in India, a series of mock up trials were initially

conducted to validate the design & construction aspects:

, Variation in temperature of fresh concrete between the core and the surface

, Permitted free fall of SCC during placement

, Distribution of coarse aggregate over the height of pour

, Quality of surface finish

, Use of 20mm maximum size coarse aggregate

, Verification of E value of concrete


Mr. Vijay Kulkarni was the second President of ICI to attend ACI Convention and meet many old, present and future benefactors of ICI. Prof R. Jagadish was the first ICI President, when he attended the ACI Convention in San Antonio, Texas in March 2009. At the invitation of ACI, Mr. Kulkarni participated in ACI Convention at

nd thTampa, Fl. held from April 2 to 6 . Dr. Sabnis helped Mr. Kulkarni introduce to as many individuals as he could in these four days of convention. He had discussions with both the President Dr. Ken Hover and Executive VP Ron Berg to set some future milestones in the mutually-beneficial activities for ACI and ICI. It is recommended that at least one officer, preferably President (VP as an Alternate) attend one convention of ACI every year to make meaningful cooperation in many areas.

There are some 100-plus Indians who are working prominently in ACI as volunteers and contribute to its success. They provide a large pool of resources for ICI with their involvement as members with their expertise in different fields. This contribution can be in terms of their attending various seminars/conferences organized by ICI in India.

They can also be instrumental in cementing ties with ACI as they are members of various committees that are useful in Indian scenario of cement and concrete research, design and construction.

There was a dinner meeting at a local Indian Restaurant in Tampa and 40 individuals including few spouses attended it. While speaking before the Indian community, Mr. Kulkarni sought their assistance in sharing of knowledge with professionals in India through the ICI route. He appealed them to join ICI as E-members (available only for foreign members) for $20/year or $50 for three years. These members will get the ICI Update, a monthly ICI journal. Plus, it will give them an advanced notice of many on-going activities in India, if they want to use their trip to India in a more useful manner. Out of some eligible 30 persons, 3 were life members already; one opted to join as Life Member ($250), three at $50 for three years and two at $20.

Mr. Kulkarni thanked Prof Gajanan Sabnis and Prof Kodur for taking painstaking efforts in organizing the dinner.

Indian members in ACI welcome ICI President

Strengthening International Relations

Mr. V.R. Kulkarni, President, ICI at the Dinner Meet Other dignitaries at the dinner meet

Indian Dinner at Tampa

Mr. V.R. Kulkarni, President, ICI and Dr. Gajanan M. Sabnis (2nd & 3rd from left) attending ACI committee meeting with

International partners

Student Chapters

A Guest Lecture on “Construction Project

Management” was organised by the ICI Student

Chapter Oxford Engineering College on

30/03/11. Er.Mohamed Rafikhan, Project

Engineer, Viswakarma Property Developers (P)

Ltd ., Tiruchirappalli, delivered the lecture. In his

lecture, he enlightened the students on the salient

features of construction project management like


Oxford Engineering College, Trichirapalli

An Industrial visit to RAN India Rolling and

Moulding Pvt. Limited, Tiruchengode, Namakkal,

was organised for the Civil Engineering Students

of the college. Students had the opportunity to

learn the steel making process and to observe the

various stages of steel making like Melting,

Tapping, Moulding Rolling, etc. They also

explained the quality control measures adopted at

all stages of the process.

Lecture by Er. Mohamed Rafikhan, Project Engineer

Visit to raw material (scrap) yard

Steel Rolling Steel Rolling

project planning, structuring the project team,

periodic review, progress monitoring, reporting,

course correction, contingency plan, etc. He

stressed the importance of house keeping at site

and the safety measures to be adhered to. He also

spoke on the job opportunities for the civil

engineers and the students had effective

interaction with the guest.


A two-day National Conference on Advances in

earthquake Resistant Design and Construction

Techniques was held at Adhiparasakthi

Engineering College, Melmaruvathur, between

April 20 & 21, 2011. This Conference was

organized by the Department under the

auspicious of ICI student chapter of APEC and was

sponsored by CSIR. The conference was

inaugurated by Prof. Dr. M. Sekar, Dean, College of

Engineering, Anna University, on 20.04.11. It was

followed by two technical sessions consisting of

keynote addresses and paper presentations. The

keynote speaker of the first session was Dr. K.

Muthumani, Deputy Director, SERC, Chennai. In

session 1, seven papers were presented. In session

2, the keynote speaker was Dr. M. Neelamegam,

Deputy Director, SERC, Chennai. In this session

also seven papers were presented.

Sessions 3 and 4 were held on 21.04.11. The

keynote speaker for session 3 was Er. P.

Sivaprakasam, Managing Director, Team

Constructions, Chennai. In this session also seven

papers were presented. The keynote speaker for

session 4 was Er. M. Karthikeyan, Managing

Director, MK associates, Chennai. It was also

followed by paper presentation by seven authors.

In each session there was lively discussion by the

participants. The valedictory function of the

conference was addressed by Prof. Dr. K. Ganesh

Babu, Ocean Engineering, IIT Madras. The chief

guests of the inaugural and valedictory function

were honoured by Dr. S. Jayashri, Principal, Prof.

Dr. V. Ramasamy, Dean and Dr. R. Rajasekaran,

Vice-Principal. The welcome address of the

inaugural address was addressed by Prof. A.

Krishnamoorthi and the same for valedictory

f u n c t i o n w a s r e n d e r e d b y P r o f . R .

Venkatakrishnaiah, both conveners of the

conference. The vote of thanks was rendered by

Prof. Dr. A. Leema Rose.

Student Chapters

APEC - Melmaruvathur - Tamil Nadu

Forthcoming Events

Call for Submissions until June 4, 2011

For Details : http://www.iabse.org/press or contact

Sissel NiggelerMarketing and Communications Manager

IABSE ETH Zurich, Hönggerberg HIL E21.3 8093 Zürich, Switzerlandtel: 41-44-633 2647 [email protected]

1. IABSE Photo Contest of Structures 2011

2. ICI-Pune Centre is organising CEMCON 2011

an International Conference & Exhibition on "Construction of High Rise Concrete Buildings (100 Mt & above)" at Sun n Sand,

Pune from 17-18 June 2011.

For details, pl contact :

CEMCON 2011C/o. Arkey Engineering & Foundry Services

Phone : 020-25670808, 25674455

Email:[email protected],[email protected]




New Members

Individual Life Members

9207 Rameshwar Dayal Singhal Jaipur

9208 Altaf Ahmed Qureshi Indore

9209 S. Geetha Chennai

9210 Vasugi V. Chennai

9211 E. Muthu Kumar Chennai

9212 Achal K. Chowdhary Indore

9213 Archana Keerti Chowdhary Indore

9215 Dr. Hemant Kumar Vinayak Hamirpur

9216 Mallela Malyadri Reddy Guntur

9217 Suresh Rao Marpally Bangalore

9218 Benjamin Michael Ernakulam

9219 M. Sabharimala Coimbatore

9220 Sayinath G. Gaonkar Caranzalem, GOA

9221 Ignatius T. Pereira Salcete, GOA

9222 Abner M. Rodrigues Margao, GOA

9223 Ajay P. Raikar Fatorda, GOA

9224 Shridhar N. Kamat Margao, GOA

9226 S. Thirumavalavan Coimbatore

9227 Deva Kumar E. Vellore

9228 Ashutosh Kumar Pathak New Delhi

9229 Yogesh Sudhakarrao Thakare Amaravati

9230 Jamdade Amol Ganpat Sangli, Maharashtra

9214 Malwa Institute of Science & Technology Indore

9225 TEKLA India Private Limited Navi Mumbai

M.No. Name Place

Organizational Life Members

MARCHMARCH


Headquarters Election

Notice is hereby given to all members of Indian Concrete Institute that the elections 2011 will be conducted

by postal ballot as per the time schedule indicated below.

NOTICE FOR ELECTION OF OFFICE - BEARERS - 2011

Ocean Crest, 79 Third Main Road, Gandhi Nagar, Adyar, Chennai - 20. Phone: 044 - 2491 2602. 4211 5996 Fax: 044 - 2445 5148

e-rnail : [email protected] ; [email protected] Web: indianconcreteinstitute.org

Indian Concrete Institute

Last date for receipt of nominations : 27.05.2011

Scrutiny of nominations : 30.05.2011

Last date for withdrawal of nominations : 10.06.2011

Despatch of ballot papers to be completed by (if there is contest) : 24.06.2011

Last date for receipt of ballots : 28.07.2011

Counting of ballots and declaration of results : 29.07.2011

Two members of the Governing Council from Chennai will scrutinise the nominations and ballots.

The electorate will be the members of the Institute at serial numbers 1-9107 whose subscriptions for the

period upto March 2011 are valid. Organisational members shall file their nominations / ballots with the

signature of their representative as given in their membership application filed at the Institute. Any change

in representation shall be notified to the Institute in writing, before filling the nominations/ballots.

The election shall be conducted to fill the following vacancies.

President (One)

Vice-Presidents (Four - East, West, North, South)

Governing Council Members (Nine) * Two to represent organisational members from among them elected by all members

* One to represent donor members from among them elected by all members.

* Six to represent individual members from among them, elected by all members.

Nominations may be filed in the proforma.

Nomination papers shall be put in a cover and superscribed :Nominations - Elections 2011" and sent to the

Polling /Returning Officer so as to reach him not later than 5.00p.m. on 27.5.2011.


Ocean Crest,

79, 3rdMain Road,

Gandhi Nagar, Adyar,

Chennai - 600020.

R. Radhakrishnan

Returning/Polling Officer

Elections 2011

P.S.: If members wish to table any resolution at AGM 2011, notice may please be given and resolutions

made available to the Secretary General before 30.6.2011 duly proposed and seconded to enable

circulation in advance of AGM 2011.



ELECTIONS 2011

NOMINATION OF OFFICE - BEARERS

Position (President / Vice President / G.C. Member)

1.

Name & Address of nominated person! Organisation

Proposed by

Name and Address

Seconded by

candidate

2.

3.

Name and Address

Nomination agreed to by the 4.

(Signature) Memb. No.:...................................................................................

:...................................................................................

....................................................................................

....................................................................................

(Signature) Memb. No.:...................................................................................

:...................................................................................

....................................................................................

....................................................................................

:...................................................................................(Signature) Memb. No.

....................................................................................

....................................................................................

:...................................................................................

:...................................................................................

Nominations shall reach the Returning Officer", in a cover superscribed "Nominations Elections

2011" before 5.00 p. m. on 27.05.2011.

A short bio-data of the candidate in not more than 100 words highlighting the contributions to

the profession and lei should be enclosed.

Use one nomination form per candidate per position

5.

6.

R. Radhakrishnan Polling / Returning Officer Elections 2011 Indian Concrete Institute Ocean Crest, 79, 3rd Main Road, Gandhi Nagar, Adyar, Chennai - 600 020

*

Note : Organisational members should sign these papers through their authorised representatives as

indicated in membership application form or as modified and notified to ICI Headquarters before

filing the nomination

Headquarters Election

Documents

Indian Concrete Institute - ICI brocher 1-20 · 2014-09-23 · ICI Update - April 2011 02 News from Centres Indian Concrete Institute, Ghaziabad Centre and UltraTech Cement Limited