Pre-Cast Technology Proves To Be The Game Changer In Construction

By Manu Sharma

Pre- cast technology or prefab has revolutionized the way builders are constructing today. As against popular belief, pre cast construction is as sturdy as conventional construction and results in huge savings in terms of time as it ensures faster delivery of homes. Manu Sharma, Editor, Silicon Village caught up with Darshan Govindaraju, Director, Vaishnavi Group regarding pre cast technology being deployed in their residential and commercial projects and Safarulla Azeez, Director, Techno-Commercial, Katerra, a company that engages in manufacturing of pre-cast structures, to get insights into the technology behind pre fab structures.

Q. How has prefab structures helped build new hospitals and quarantine facilities across India in record time through the covid-19 pandemic?

Darshan Govindaraju: Whenever there is large requirement with less manpower and less time, standardization of construction elements and size, modular system comprising Precast  elements, MEP , finishes etc prefab is best the option to build  hospitals/quarantine facilities in less time due to very less activities at site

Q. How much cheaper are prefab homes compared to other homes? Please justify with numbers.

DG : Prefab homes are known for their better quality, faster timelines and accuracy and precision in dimensions, however the same can be deemed economical when there is a mass construction involved with considerable repetitions. And when compared with the return on investments, time benefit analysis and long maintenance, etc, offsite manufacturing could be cheaper on a larger picture.

Q. How does your manpower, who are well versed with the old/traditional building technologies cope with this technology? Is there any training involved or you employ only those with knowledge on this technology?

Safarulla Azeez: We at Katerra has a mix of both skilled and relevant experienced manpower and also the people proficient in traditional construction methodology who were open for learning and evolving over time. Katerra however provides an extensive training during the induction period for all the employees to cope with the precast and prefabrication technology.

Q. How durable are prefab homes compared to the traditional ones?

SA: Precast homes are much more durable than conventional homes as predominant material is RCC in case of precast while it is still brick and motor in traditional methods. At Katerra our precast building components are from a bare minimum of M40 grade up to M60 as per the design requirement, which induces additional strength and durability. Also the precision of the reinforcement laying, stirrups, cover maintained, uniform compaction  ,  concreting in controlled environment , strict quality check at factory & curing and mould finish are few value additions which eventually help in enhancing the structural durability of the homes.

Q. Are prefab energy efficient? If yes please justify the claim?

SA: Precast technology is definitely energy efficient approach during construction as there would be limited manpower, minimum water consumption as it is artificial curing using steam chambers, carbon footprint for production is less when compared to traditional methods, etc. Katerra has executed projects for Infosys, Microsoft, BOSCH, etc which are LEED/IGBC rated which shows the impact of energy efficiency during execution. Offsite manufactured buildings are also energy efficient during life cycle, as plastering is completely eliminated there is no requirement of regular maintenance to avoid shrinkage cracks, factory produced components have minimum rate of corrosion as cover is maintained accurately. Also, RCC in general is a better energy efficient material over traditional brick and motor.

Q. Why aren't prefabricated homes still not popular in India?

SA : Construction has always been the biggest unorganized sector in India making it difficult for adopting global technologies. However, India is continuously evolving in terms of construction technology and in fact precast/offsite manufacturing has penetrated in the last decade. Currently all the government construction authorities are making steps towards developing special codes for precast/offsite manufacturing which will eventually pave path and encourage more precast homes and buildings in India. With the evolving market the limitations in flexibility for changes or modifications are eliminated and making the precast homes more popular in the urban market. The other reason was technology through right equipment and machineries were not in place, and as Katerra we have implemented new technology and equipment from different part of the world which enhance the prefabrication and precast technology more popular in India.

Q. One of the disadvantages of prefabrication has been promoting repetitive, monotonous patterns, or series in order to be economically feasible. How to overcome this challenge?

SA : It is a misconception that precast need to adopt monotonous patterns, with the efficient design for manufacturing and assembly (DFMA) we need to ensure the repeatability of the building components without compromising on the architectural layouts, variations and patterns. Repeatability to be achieved by standardizing the building heights, lift and staircase cores, wall panel dimensions, etc but simultaneously providing flexibility in the floor layouts, room dimensions, window & door openings, etc. Katerra is equipped with an inhouse design team to support for the probable design value additions in a much early stage to maintain repeatability without limiting developers to monotonous box designs.

Q. Since the slabs, pillars are others have been constructed in large numbers at an offsite location, transportation is another major problem in the prefab modules and might be hard to manoeuvre to reach locations in a city. How is this being handled?

SA: In our precast approach 80 percent of the precast components are manufactured in our factory and transported to site for installation. As per our past project experiences and analysis we realized there would actually be a reduction in the vehicular movement to construction site due to transporting finished components rather than the raw materials like cement, sand, aggregates, steel, etc or the concrete RMC mixers on a daily basis. Moreover, most of the transportation shall be undertaken during night abiding by the regulations which will not impact any traffic movement in and around the construction site. Katerra has executed complex projects in the most congested areas of the Bangalore like Electronic city, Bellandur, Embassy Golf Village, Embassy Tech Park. We have also executed a project with just in time approach due to unavailability of stockyard space at site. Precast technology adoption would be much more advantages at such sites as most of the activity is completed at site.

Q. How have your customers' responding to this kind of homes? Will you be building more apartments/homes using this technology in the future?

SA : There are lot of enquiries from different customers and very positive response also. Yes, Definitely Katerra will be interested in building more apartments and homes using this technology. We are in to more innovation and R&D in this sector like volumetric construction etc…