Precast concrete construction in India and Indian Standards

Precast concrete construction is a method where concrete elements are cast in a controlled environment, typically a factory or precast plant, and then transported and assembled at the construction site. This approach offers numerous advantages over traditional cast-in-place concrete construction, including speed, quality control, cost-effectiveness, and sustainability. Here's an overview of precast concrete construction:

Manufacturing Process

The manufacturing process consists of the following steps:

Formwork: Precast concrete elements are cast in reusable molds or forms made of steel or other materials. These forms are designed to create the desired shape and finish of the concrete element.

Concrete Mix: High-quality concrete mixtures are prepared using specified proportions of cement, aggregates, water, and sometimes admixtures to achieve the desired properties such as strength, durability, and workability.

Casting: The concrete mix is poured into the forms and allowed to cure and harden under controlled conditions, such as temperature and humidity, within the precast plant.

Demolding: Once the concrete has achieved sufficient strength, the forms are removed, and the precast elements are carefully demolded and finished according to project requirements.

Transportation

After curing and finishing, the precast concrete elements are transported to the construction site using specialized vehicles such as flatbed trucks or trailers. Careful planning and logistics are essential to ensure the safe and efficient delivery of the elements.

Installation

At the construction site, the precast elements are lifted and positioned into place using cranes or other lifting equipment. Connections between elements are typically made using bolts, welding, or grouting.

Precast elements may include structural components such as columns, beams, and panels, as well as architectural elements like cladding panels, facades, and decorative features.

Advantages of Precast Concrete Construction

Speed: Precast elements can be manufactured concurrently with site preparation, reducing overall construction time and accelerating project delivery.

Quality Control: The controlled environment of precast plants allows for precise monitoring and quality control of materials, production processes, and finished products, resulting in consistently high-quality elements.

Cost-Effectiveness: While initial investment in precast concrete molds and equipment may be higher, the overall cost savings can be significant due to faster construction, reduced labor requirements, and minimized waste.

Sustainability: Precast concrete construction can contribute to sustainability goals by optimizing material usage, reducing construction waste, and incorporating recycled materials into concrete mixtures.

Applications

Precast concrete construction is widely used in various building types, including residential, commercial, industrial, and infrastructure projects.

Common applications include parking structures, bridges, office buildings, residential developments, stadiums, and transportation facilities.

Thus, precast concrete construction offers a versatile and efficient solution for a wide range of construction projects, providing benefits in terms of speed, quality, cost-effectiveness, and sustainability. Its use continues to grow as developers and builders seek innovative methods to streamline construction processes and enhance project outcomes.

Indian Standards on Precast Construction

The Bureau of Indian Standards (BIS) has issued the following codes related to precast concrete construction in India.

1. IS 15916 (2020): Building Design and Erection Using Prefabricated Concrete - Code of Practice (First Revision)

This standard provides guidelines for designing and erecting buildings using prefabricated concrete components. It covers aspects such as safety, materials, and construction practices. It emphasizes the need to avoid “progressive collapse” and promotes the use of locally available materials for cost-effectiveness and improved quality.

2. IS 15917 (2020): Building Design and Erection Using Mixed/Composite Construction-Code of Practice (First Revision):

This standard covers system building and mixed/composite construction, it also specifically addresses systems using predominantly concrete as material for components. It complements IS 15916 by focusing on mixed construction techniques.

3. IS 15658 (2021): Precast Concrete Blocks for Paving-Specifications (First Revision) (with 1 Amendment)

This standard pertains to precast concrete blocks used for paving purposes. It specifies requirements for their dimensions, strength, and durability.

In addition to the above recent standards, BIS has also released the following standards.

4. IS 10297: 1982 Code of practice for design and construction of floors and roofs using precast reinforced/prestressed concrete ribbed or cored slab units (With 2 amendments)

5. IS 10505: 1983 Code of practice for construction of floors and roofs using precast concrete waffle units (With 1 amendment)

6. IS 11447: 1985 Code of practice for construction with large panel prefabricates (With 1 amendment)

7. IS 13990: 1994 Precast Reinforced Concrete Planks and Joist for Roofing And Flooring

8. ?IS 13994: 1994 Design and Construction of Floor and Roof with Precast Reinforced Concrete Planks and Joists - Code of Practice

9. IS 14142: 1994 Design and construction of floors and roofs with prefabricated brick panel - Code of practice

10. IS 14143: 1994 Prefabricated Brick Panel and Partially Precast Concrete Joist for Flooring and Roofing

11. IS 14201: 1994 Precast reinforced concrete channel units for construction of floors and roofs - Specification

12. IS 14213: 1994 Code of practice for construction of walls using precast concrete stone masonry blocks

13. IS 14215: 1994 Design and construction of floors and roofs with precast reinforced concrete channel units - Code of practice

14. IS 14241: 1995 Precast reinforced concrete L - panel for roofing - Specification

15. IS 14242: 1995 Design and construction of roofs using precast reinforced concrete L - Panels - Code of practice

16. IS 3201: 1988 Criteria for design and construction of precast concrete trusses and purlins

17. IS 6072: 2023 Autoclaved reinforced cellular concrete wall slabs Specifications First Revision

18. IS 6072: 1971 Specification for autoclaved reinforced cellular concrete wall slabs (With 3 amendments)

19. IS 6073: 2006 Autoclaved Reinforced Cellular Concrete Floor and Roof Slabs (With 1 amendment)

The above codes play a crucial role in ensuring safe and efficient construction practices in India. They cover various aspects of design, materials, and construction techniques related to prefabricated concrete. If someone is involved in precast construction, these standards provide valuable guidance for achieving quality and safety in the projects, handed by them. More information on precast concrete, its benefits and challenges in India, and the factors affecting the productivity and functionality of precast concrete building construction in India may be found in the following references.

References

1.?????? Ahmed, A. and Mandal, A.K. (2020) Benefits and Challenges of Precast Construction in India – A Review", SSRG International Journal of Civil Engineering, Vol.7, No.7, pp. 7-10.

2.?????? Balakrishna, B. (2014). “The Indian Precast Industry –Gaining Prominence”, The Masterbuilder – Precast Digest,1(1), 8-14.

3.?????? MoHUPA (2012). “Housing For All by 2022”, Ministry of Housing and Urban Poverty Alleviation, Govt. of India, viewed 20th Mar. 2024, https://mhupa.gov.in/W_new/Housing%20for%20All.pdf

4.?????? Prasad, C.A. (2022) Precast Construction in India and its Future Ahead", CECR, https://www.cecr.in/precast-technology-1/precast-construction-in-india-and-its-future-ahead

5.?????? Ramakrishna, A. (2012). “Pre-cast concrete in Buildings and Urban Infrastructure”, Two-day National Seminar on Modern Equipment for Concrete Construction, Indian Institute of Technology Madras, Chennai, India.

6.?????? Sherfudeen, A.P., Pillai, R.G., Raghavan, N., Kalidindi, S.N. (2020). “Factors affecting productivity and functionality of precast concrete building construction” The Indian Concrete Journal, Vol. 94, No. 9, pp. 23-34.

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