Value Engineering for Concrete

S.A. ReddiDy. MD (Retd) Gammon India Ltd.

VALUE ENGINEERING is …

Systematic application of recognized techniques by a multi-disciplined team, which

- identifies the function of the product- establishes a worth for that function - generates alternatives and - provides the needed functions with lowest

overall costs.

Value Engineering (VE) Application for Construction Projects

Value Engineering is a technique used for identifying and eliminating unnecessary costs in design, constn , maintenance of Civil Engineering projects.VE is effectively used by having a

performance specification combined with a design-and-construct form of contract as is being practiced in developed countries.

VALUE ENGINEERING-HighwaysStages of Applications

ConceptQuality assuranceAnalysisDesignDetailingTemporary worksConstructionMaintenance

Value Engineering Manager’s contribution to Poor Value

Lack of information ; shortage of time

Honest wrong beliefs ; Fossilized ideas

Habitual thinking ; Resistance to change

Reluctance to seek advice ; Negative attitude

Lack of awareness of Changing Technology

Performance at any cost

Poor human relations

Potential Areas for VE EffortFeasibility Stage

Necessity for the structureChoice of structure location Design before or after contract award Departmental / contractor’s alternative design / consultant’s designStructure Rehabilitation Vs new structure Role of Proof Checking Agency

VE- CODES, SPECS

Codes & Specs should remain flexible.Under the control of the owner,they should leave the responsibility to the designer for the selection of material and technology.

It is extremely expensive to overreact to events and to overrule methods which have been found generally successful over many years.

VE- CODES, SPECSReinforcement - MORTH Specs.2001Cl. 1009.3 specifies only Fe 415 grade. “ other grades of bars confirming to IS 1786 shall not be permitted”The restriction is arbitrary; the whole developed world allows use of Fe 500, 550 grades. These grades are included in IS 1786 Even IRC 21 – 2000 permits Fe 500 grade !Thus two documents brought out by the same agency contradict each other. No solution for the last seven years !

VE- CODES, SPECSMinimum Cement Content

IS 456 300 - 360 kg for different exposures IRC 21 380 - 400 kg for all exposuresSugen Cooling Tower, Gujarat 425 & 450 kgPrivate sector consultant specs, Bangalore

300350M25320390M30340435M35360460M40

300320M20IS 456Minimum cement Kg/cumGrade of Concrete

Ambiguity in Table 5 - IS 456

M 400.40360ExtremeM 350.45340Very SevereM 300.45320SevereM 250.50300ModerateM 200.55300Mild

Min Grade ConcMax. w/c RatioCement(Kg/m3)Exposure

Table specifies minimum cement content, Max. w/c ratio, Min. concrete grade. Each related to exposure conditions independently however many users misinterpret the table; minimum cement is not to be correlated with either w/c or concrete grade; each column should refer to exposure condition only

Value Engineering due to Alternative Design220m Chimney for a TPS near Delhi

5650 cum7500 cumShell concrete

444 t700 tShell Reinf

3 weeks3 monthsTime taken for concreting pile cap

302 t600 tPile Cap Reinf

3900 cum7500 cumPile Cap concrete

Alternative design by ContractorConsultant designDescription

Value Engineering - Reinforcement Cooling Towers and Chimneys

5 Natural Draught Cooling Towers (NDCT) and 6 Chimneys (up to 275 m) under construction by GILShell reinforcement in NDCT : 600 t

Chimney : 1200 tTotal quantity of reinforcement required for above jobs: 10200 t (approx)Usually 4 m bars used in chimney and 4.5 – 6 m in CT, depending on speed of slipform; if speed is increased 6 m can be used uniformly

Value Engineering - Reinforcement Cooling Towers and Chimneys

30 % extra laps can be avoided if 6 m bars are used uniformlyOnly few diameter bars required in 6 m lengths (10, 12, 16 mm). Large quantity required if procurement on company wide basis Most of the manufacturers ready to supply custom-made sizes of reinforcement bars if quantity is more than 200 t

Specification overkill !!!

It involves, much of the time, paying more thanneeds to be paid to buy a level of protectionthat, in many cases, cannot ever be needed,from which no good can ever be derived.

‘ever’ means not more than once in a millionyears! Stamp out specification overkill, ensure

quality to match the importance of structure

VE- Specifications Check List

Are the specifications realistic?Are they required or guidelines only?Are the specs interpreted correctly ?Specified characteristics necessary ?Specs requirements reviewed ?Can they be modified or eliminated ?Modifications simplify design,constn ?

VE-Engineering & Design

Who determines the performance reqd?Performance of similar structures nearby ?Who is authorized to review changes?Alternatives considered during design?Reasons for rejecting the alternatives?Does it reflect the latest state of the art ?Life cycle cost of the chosen alternative ?Catering for more than what is required?

Potential Areas for VE Effort ( VE Textbook FHWA - HI - 88 - 047 )

Design complexity , Safety Factors, time shortageAdvancement in the state - of - the – art

Intricate shapes, difficult to construct Deep foundations, Excavations Dense reinforcement, Items requiring high skills Architectural Embellishment Record Seeking DesignsItems with poor service or cost history

Beam column junction constructability ensured by avoiding lapping of bars, using couplers

Congested column reinforcement, expensive to pour concrete

Potential Areas for VE Effort

Protective Coatings to reinforcement, concreteItems having maintenance problems Standard plans in use > 3 or 4 yearsMinimum Quantity Design Simply supported deck spans ; wearing coatsSpecified min web / deck / soffit thicknessPermissibility of deck slab Permanent formworkComplicated Continuity Systems for deck

Potential Areas for VE Effort

Inappropriate Loading StandardsUnrealistic load CombinationsAdopting Nonstandard Materials, componentsLow grade concrete, reinforcement; higher grades (M 40 – M 80 concrete & Fe 500 reinforcement reduces overall cost) Bridges : Insistence on Box Girders / Intermediate diaphragms; restriction on Two - Girder deck; articulations in bridge deck banned

Conc. Strength, MPa50 70 85

0.9

1.2

1.5

1.8

Bea

m d

epth

, m

(Girder Depths for 30 m Span)

SAR/06-

Advantages of Using High Strength Concrete

Columns - Benefits of Using HPCReinforcement Reduction / Reduced Section

Girders at 1.2 m c/c ; 9 x 30 strands = 270 nos

Girders at 2.75 m c/c ; 9 x 58 strands = 232 nos

Bridge Deck Benefits of Using HPC

150 tkDeck

200 tkDeck;No wearing coat

40 Mpa

70 Mpa HPC

Value Engineering Par Excellence3 Bridges and a Crane !!!

Great Belt West Bridge in Denmark 6.6 Km long designed based on 6000 t modular precastconcrete components A self propelled floating crane, (SWANEN) 6000 t

capacity designed and manufactured by the contractor exclusively for the project Confederation Bridge Canada (13 Km) designed

to suit SWANEN which was used in constructionOresund Bridge, 15Km (Denmark – Sweden)

again planned, constructed using SWANEN.

6.6 km Great Belt West Bridge, 1995 Denmark

SAR 05 Y2

13 km long Bridge Canada

21 km Bridge connecting Denmark and Sweden

1

2

3

I : Cable stayed bridge laid on bearing at 900 to final location

Value Engineering EPC Contract

Flyover in CapeTown SA constructed without

traffic disruption

III: Bridge is ready for traffic

II: Bridge swung without stopping traffic

VE - Methods and Processes

How is the construction performed ? Why is it performed that way?Can functions be combined,simplified ?Any nonfunctional items required ?Is there scope for further mechanization?High cost areas or items identified?What is the Schedule ?Is there a methods statement prepared?

VE –Materials Management

Special / long lead / costly materials specified?Alternate materials considered ? RMC/ HPC/ HS SteelAny hazardous,difficult to handle items?Any price, delivery, quality, monopoly problems ?Are the specified materials still valid ?Any new

materials be specified?l Types of Cement , Fly ash, Slag, Aggregates – use of gravel, 40mm max size for RCReinforcement, Higher Grades Fe 500Problems with Brand Names

VE – Maintenance of Structures

Has the item been observed in use ?Ideas from users/maintenance staff ?Different categories of maintenance? What is normal maintenance ?What is the frequency of maintenance ?What is the level of maintenance ?Any repairs / rehabilitation carried out ?History of replacement of components?

Value Engineering

Indian Experiences

Value EngineeringHistory of Design-Build Contracts

Almost all major road bridges until 1985 were realised by Design-Build contracts Outstanding examples include

The first prestressed concrete Railway Bridge The first prestressed concrete Road BridgeThe first and subsequent Cable Stay BridgesThe first Segmental Cantilever Bridge (Barak)The first precast, epoxy glued, long span

cantilever segmental bridge (Patna)

Value EngineeringCase - Coronation

Bridge, WB

Design and build contract Foundations in water avoided The 81.7m reinforced concrete Arch constructed

utilizing unique enabling works. Approximately one third of arch length from each pier concreted utilizing cantilever gantries and tie back The central portion temporarily spanned by a

steel Melan Arch which supported the form work for concreting and act as reinforcement

Value Engineering CaseNapier Bridge Chennai

100+ year old bridge, exposed to sea

Steel deck corroded, replaced in 1943 by RC bowstring girder deck, now in good health!

There was no SP 33 in 1943!

The engineer who designed the bridge, was also in charge of supervision of construction

Now, 2 lane bridge added, same old design!

Ganga Bridge Patna – 5575m, 4 LanesRiver gravel used as coarse aggregate

Value EngineeringGanga Bridge Patna (1980)

India’s longest Bridge (5.575 Km ) built on 55m deep well foundations, RC piers supporting PSC cantilever deck (pre-cast segmental construction)VE applied during construction :

- Floating caissons avoided by river training - River gravel used for major portions - 40 mm aggregates for RC pier - Economical concrete mix - Epoxy formulations developed at site

Value EngineeringAkteshwar Bridge, Gujarat

Extensive floods damage some piers11 out of 15 spans washed away Options : Rehabilitate or construct new bridge Government opted for rehabilitation Piers strengthened and raised by 4m Undamaged decks raised by 4m New deck replaces damaged spans

A cost effective VE solution !!!

Value Engineering : CaseMorhar Bridge NH-2 Bihar

Century+ old 14 span arch bridge suffered collapse of few spans in early SeventiesDecision to rehabilitate instead of New Bridge construct PSC Deck on existing foundations & piers, after controlled demolition of all archesTough bench mark of 8 months to reconstruct.

Eight beams per two lane deck to reduce pre-cast beam weight. Beams steam cured .

Akkar Bridge in Sikkim (1985)

77m 77m

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Value Engineering – Cable Stay BridgesCase – Akkar Bridge in Sikkim (1985)

First all concrete cable stay bridge in India

Designed and constructed by GAMMON

Consultant - Schlaich and Bergermann, Germany

Scheme suitable for developing country

Only indigenous materials used

Stay cables manufactured at siteCost effective alternative design, contract secured by

open competition 6

Steeply sloping rock for two foundations- CS proposed with two spans of 348m;

Four caissons 9m dia under each pier Aqua header) for rock cutting, even seating

CS proposal not carried out: - Very expensive, verified by bids - Greater construction time ion

- Technology import requirement; Aqua headerequipment not suited for hard rock cutting

Value Engineering – Cable Stay OptionCase – Brahmaputra Bridge, Jogighopa (1997)

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MSRDC - Design Criteria (Special Features)

50 Flyovers in 2.5 years (Rs. 1500 Crores.)Lump sum contract, Contractors’ designIRC Criteria modified by spl. committeeLive load - One Class A train per laneAllowable compressive stress 0.33 fckSuperstructure - continuous for Live LoadsIRC SP 33 not applicable Conc., Steel, Composite permittedSavings due to Value Engineering : Rs 300 crores

250

525

350

6000 5606

250

450

250

16300 16275

Yamuna Bridge, Delhi Simply supported

Yamuna Bridge, NoidaContinuous, Externally

Prestressed

450 350

700

R = 250 488

250

Advantages – Continuous, Externally Prestressed Bridge

Value Engineering Chennai Flyovers

Nine Flyovers constructed during 1999-2000Construction drawings with tender documents About 20% saving compared to estimate Average construction time / Flyover ; 9monthsDeck beams standardized ; Design permits

prestressing for self weight at 24 hrsRMC predominantly usedPier CS standardized ; FRP shuttering used

Value EngineeringCase: Kosathalayar Br TN NH-5

100+ years old bridge, with no foundation except a 600 mm rubble apron at bed levelTwo spans collapsed in early Nineties due to

undermining of apron by illegal sand quarry operations!New bridge constructed, 20m deep piles Morhar-type solution was possible at a fraction of

cost! A FIT CASE FOR VE

Value Engineering assessment

More cost effective solutions are available for similar

layout, avoiding foundations in rail track portion

Fast track construction possible with such solutions

Elimination of expansion joint possible even other

wise

Cost per sq.m CS Bridge Rs 47,000

Conventional ROB Rs 13,000

Value Engineering – Cable Stay BridgesCase – CS ROB, Krishnarajapuram, B’lore 1999

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All existing bridges in and around Allahabad, both across Ganga and Yamuna are of conventional spans, constructed by Indian contractors

The PQ criteria for cable stay bridge results inexpatriate prime contractor, with Indian sub-contractors; substantially higher project cost

Decision on successful bidder aftercomplicated evaluation takes time

Value Engineering – Cable Stay BridgesCase : Yamuna Br., Allahabad 1999

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Value Engineering- Bridges Present Indian Scene - 2007

During the last five years, heavy investments have been made for construction of urban flyovers, elevated roads, elevated railways

Locations include Mumbai, Delhi, Chennai, Calcutta, Bangalore, Hyderabad, Ahmedabad, Jaipur, Guwahati, Surat, Ludhiana, Pune, Nagpur, Madurai, Tindivanam and other cities

Bridges and flyovers in the pipeline. During the next five years, expected outlay : Rs. 50,000 Cr.

Value Engineering- Bridges

Bridge costs in India are substantially higher A structure which makes economic use of

materials, and can be built easily and quickly,is likely to be the least cost option

Alternate designs by the bidders based on theabove, may result in savings up to 20%

Rationalising codes and specifications can reduce cost by about 25%

Value EngineeringCost of Indian Bridges

Between 1961 and 2000, the cost per square m of bridge deck has increased 50 to 60 times Corresponding increase in Labor, Materials and

Plant is about 30 times (weighted average)Balance increase is attributable,inter-alia due to :

Revised conservative specificationsAdverse changes in decision making Revised stringent codal requirementsDiscontinuing design – build contract

Value Engineering :Bridge Foundations

Scour Assessment incorrectConsequent unwarranted deeper Foundation Satisfactory Past Performance ignoredConsequences : Time/Cost over-run , FrustrationConservative Permissible bearing capacity Pile Load Tests - initial / worksWell sinking through Hard RockEven Seating of Wells on Hard Rock

VE – Faulty Assessment of scourSubstantial Time/Cost increases

Kandoor Br (H.P.)Kali Bridge (Karnataka) Tapi Bridge (Maharashtra)Varanasi Br (U.P.)Farakka T T foundations (W.B.)Passighat Bridge (Ar.P.)Zuari Bridge (Goa)

Value Engineering Foundation Depths

Design Depths increasing every decade !

Case - Ganga Bridge at Varanasi Railway bridge, 19th century 42mRoad bridge 1990’s 57m

Both the Bridges are next to each otherCase - Sone Bridge Dehri on sone

Railway Bridge (1900) 15mRoad Bridge (1965) 23m

Piles are cost effective, aids fast track work Design should be based on structural

requirements.Why specify minimum no/ foundation? Permissible bearing capacity should be realistic In

Mumbai, under similar rock conditions, two Engineers have specified SBC of 700 & 300 T/m2 ! Pile dia could be reduced from 1200 to 800mm

Why specify excessive socketing depths in hard rock

Value EngineeringPile Foundations

VE Typical Bid Document Design Data, Specifications

Special Specifications ; “If design and construction of any particular item of work are not covered by the codes & specs listed above or deemed so by the Engineer, the same shall comply with special specifications confirming to sound engineering practice….. The decision of the Engineer in respect of such specifications shall befinal and binding on the contractor”Such open ended clauses play havoc !

VE Typical Bid Document - Bridges Structural arrangement not permitted

Structural sensitive to unequal settlement Structure with single Articulation in a span Structure with hinges Super structure with Articulated supportDeck slab with transverse pre stressing Steel Bridges Stone / Brick masonry structures

Why are these not permitted ?

VE Typical Bid DocumentRamanaya of Pamban Bridge

Bids invited in the early seventies for this longest bridge in Tamil Nadu, that too in open seaPrice variation clause not acceptable ; In

consequence, bids of all established Bridge builders not considered. Job awarded to ‘X’, who could not complete.

Contract terminated at his risk and cost Work continued departmentally for some time.

The bridge could not be completed

VE Typical Bid DocumentRamanaya of Pamban Bridge

Fresh bids invited in early Eighty’s. Work awarded to ‘Y’, after two years of negotiations Bridge completed in 1988 at much higher cost,

about three times the original bid The public was denied its use for ten years ‘X’ had sought arbitrations, claims compensation ‘Y’ Had also sought arbitration for escalation

A classic case for value analysis

Value Engineering

American Experiences

Value Engineering ( VE)US Transportation Sector

Federal, State Govt.. Strive to establish value for the tax payer’s dollar

VE has led to innovation, cost effectiveness and improved quality in design & constn.

The Public Transportation Sector, faced with rising costs, has turned to VE to optimize use dwindling resources

Value Engineering ( VE)US National Highway System Act -1995

The NHS Act of 1995 includes a VE provision to “Establish a program to require States to carry out a VE Analysis for all projects on the National Highway System with an estimated total cost of US $ 25 million or more The FHWA published its regulation establishing

this program in February 1997 requiring VE Analysis of all projects over $ 25 m on the NHS, to receive federal funds

VE Effort - CALTRANS Experience (AASHTO VE Conference, July ‘99)

CALTRANS Operates VA Program since 1969 VA Program Guidelines adopted in 1995 PRODUCT STUDIES utilized the VA process to

improve the quality of highway products Standard Plans, Specs need updating due to

changing technology, outdated application etc VA Training: A 40 hour Workshop run by

Society of Value Engineers , provided by National Highway Institute since 1998

Value Engineering Proposal FHWA Standard Special Provisions 1997

The successful Contractor submits VE proposal for reducing cost along with designs, drawings, advantages and requests for modifications If approved, the necessary changes will be

effected by Supplemental Agreement

The net savings will be prorated, 50% for the contractor & 50% for the Department The Department bears the VE review costs The

Contractor bears designs/ drawings cost

Value Engineering Proposal FHWA Standard Special Provisions 1997

VE applied during planning/ design/ construction Design VE conducted by the Dept / ConsultantsSavings quantified by the Department Contractor’s VECP must be a stand alone one

SHA contracts allow VE change proposals. All projects are eligible for such proposals

VE Studies are performed in the design stage ;

VE change proposals in the construction stage

Value Engineering

European / Canadian cases

Precast pre-tensioned beams, factory produced

Pre-fabricated elements for foundations, piers

Factory made beams / segments

Match cast segments, short line method

Pre-tensioned beams up to 45m span

Precast segments upto 26m width

Precast unit weight upto 8000 tonnes

Value EngineeringDevelopments in Precasting

Value Engineering Paving Equipment, methods

Slip form pavers of width 3.7 to 18.3 m available Paving speeds of upto 1Km per day Concrete production, transportation to match Bench marking of construction speedThe weakest link is the speed of feeding concreteDue to fragmented contracts in India, pavers

procured by contractors grossly under usedIn consequence, tender prices go up!!

Value EngineeringConcrete Paving Over-specified in India

Concrete mix proportioning method obsolete leading to increased cost : - More cement content, about 400 kg (should not

be more than 350 Kg/m3)- Max aggregate size 20 mm (should be 40-63 mm)- Full width paving in one operation : many contracts specify single lane paving Contract size should be large enough to justify

effective utilization of pavers

Value Engineering European Paving Specifications

Country Thickness Strength Min cementmm Mpa Kg/cum

Denmark 200 50 300France 200 5(flex) 300Germany 160-270 40 300UK 40 300

---------------------------------------------------------------------India 350 35-40 375-437

Value Engineering - Highways Suggestions

Review, update IRC codes, MOST SpecificationsAlign with IS 456 : 2000 / EUROCODESPrepare codes for pretensioned concrete and for

continuous structures. Withdraw SP 33 in toto Introduce Value Engineering in major contracts Resume design- build contracts for large jobs Do not over specify in tender documents Do not specify equipment numbers, capacities in the tender. The bidder should specify the same

Value Engineering Issues for consideration

Should VE be made compulsory for major jobs ?If so, at what stage ?Who will be the agency to propose VE ?How will the savings be shared ?Will there be conflicts with design agency ?If so, who will resolve the conflict ?Should there be Parliamentary Enactment ?What are the reactions of MOST, NHAI, PWD’s ?

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