precast concrete construction for buildings - a system

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Precast Concrete Construction for Buildings -

A System ApproachBy

N.Raghavan, FNAE, FICE(UK), FIE(I)Professor of Practice – IITM

BMTPC Navaritih, November 2021

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Presentation Roadmap

IBS- Industrialised Building Systems. PCConS- Precast Concrete Construction Systems

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Industrialised Building Systems-Adv.s

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IBS systemsa) Precast Concrete Construction System (PCConS):

Linear Framing / Planar Panels and Slabs / 3-D Box Systems.

a) Cast in-situ concrete work with System Formwork (Ex. Alu. Formwork), Frames and Blockwork systems, Tilt-up construction, Lift Slab construction, etc

b) Structural steel systems- PEBs, Prefab. frameworks, expanded steel systems, with cover boards, etc

c) Prefabricated Timber Framing System

d) 3D Printing

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Advantages of PCConS

* Life Cycle Cost

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Some Examples of Fast Construction

Examples for Pre-fabricated Construction

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Earlier Examples of PCConS Projects

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48 hour home

• Completely finished 124 • sq. m. 4 bed room family

home, built in 48 hours! (Saudi Arabia,

• Dec 2018, • by Katerra)

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Examples from China

• Bldg in Schenzen in just one day

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Examples from China• Speed of 3 storeys per day!• Achieved using

prefabricated elements

(Broad Constructions)

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Development of PCConS

ITPL Bldg

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Status

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Available Standards & Specs

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Status - Overall Broad Snapshot

• Demand Side– Inadequate demand, inhibiting growth– Poor awareness/ capabilities inhibiting demand

further– Bidding conditions not favourable to PCConS– Testing & Certification facilities absent

• Supply Side– A mix of site-specific projects and a few plant-based– Too much variation in the absence of strong

standardisation– Only a few agencies have the fully integrated

systems– Capabilities limited to only a few

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The Main PCConS Systems

Framed Structures

Wall & Slab Panels

3D Volumetric elementsPrecast

Concrete Façade Panels

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Some Main Steps in doing PCConS•Identify Project Parameters:

● Housing (small spans, simpler internals) / commercial structure (large spans, MEP intricacies)/Car park,….….

oDecide functionalities- type of structure, size, internal dimensions, specific requirements, aesthetics requirements, time lines, cost budgetsoDecide system of precasting- framed, panels, volumetricoChoose manufacturer and obtain details, type and sizes of elements

available, jointing systems, etcoArchitectural design using the chosen elementsoStructural design and jointing systems: usually by ManufactureroDecide site-based manufacture or factory basedoDecide Construction methods- tower crane, mobile crane, other

methods,…oBid out; Award, Construct, Test (??)

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PCConS- Requirements

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Some Issues involved in aboveNon-uniformity/ lack of standardisation in elements – due to lack of

unifying statutory/ industry standards. Any manufacturer’s products may not match others’ systems! Need for uniform tolerances

Testing & Certification for “standard” off-site factory-produced elements – for dimensions, joints, structural design and capacity, reinforcement and fixtures provided, functionality, material properties, robustness / functionality of joints

Lack of Inspection & certification agencies specialized in PCConS technology

Contractual issues: problems of using documents of in-situ philosophy for precast methods; lack of official technical specifications & contract conditions

Poor transportation systems/ facilities (roads, etc) for long distance transportation of factory- manufactured elements

Lack of general familiarity of Architects/ Designers for PCConS systemLack of an unifying Handbook, similar to PCI Handbook of USA!

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The many different connection systems

Two St age JointOne Stage Joint

Compressible sealant JointOpen drained Joint

Joint Testing Set-up

Typical Joints- Panel to Panel & Functional Testing

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Impediments to Widespread usage of PCConS

* CREAM – Constn Research Inst. Of Malaysia NPCA- Natn’l Precast Concrete Asscn

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PCConS- Some Enablers

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Some Recent Positive Developments

*ASHA – Susstainable Hsg Accelerators- India Su

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IS:15916-2020- ContentsIS 15916:2020 Building Design and Erection Using

Prefabricated Concrete - Code of Practice (well updated)1 SCOPE

2 REFERENCES

3 TERMINOLOGY

4 MATERIALS, PLANS AND SPECIFICATIONS

5 MODULAR COORDINATION, ARCHITECTURAL TREATMENT AND FINISHES

6 COMPONENTS

7 PREFABRICATION SYSTEMS AND STRUCTURAL SCHEMES

8 DESIGN CONSIDERATIONS AND REQUIREMENTS

9 JOINTS

10 TESTS FOR COMPONENTS/STRUCTURES

11 MANUFACTURE, STORAGE, TRANSPORT AND ERECTION OF PRECAST ELEMENTS

13 PREFABRICATED STRUCTURAL UNITS

ALSO, NEED FOR AN UNIFYING PCCon HANDBOOK!

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Concerned Agencies• MoHUA- Min. Of Housing & Urban Affairs• BMTPC- Bldg Matls & Tech Promotion Council• PSI (PESSI): Pre- Engineered Str.s Society of India • BIS-Bureau of Indian Standards• ICI- Indian Concrete Institute• INAE- Indian Natnl Acad of Engg: INAE Forum on Civil Infra

(Housing)

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The Industry Body

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Who can “Help”

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Conclusion• The industry and various stakeholders should

collaborate together and identify the steps to be taken to help the industry, as well as to implement the same.

• If that is done in the near future, it will lift up the Utilisation and Performance levels of the entire PCConS industry in the country by many levels and also benefit the ultimate users.

• Global Precast construction market has forecast a CAGR of 6.6% during 2019-26. Look forward to a great growth for this Industry!

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All the Best! Stay Safe!

Wish you Happy Precast Construction!

THANK YOU

precast concrete construction for buildings - a system

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