Central Vista
Brand new buildings with cracks
Will have to be rebuilt in ten years.
Civil construction was always cookie cutter. U built standards compliant buildings and the buyer paid as per a look up table. There wasn’t much technology involved and one contractor was pretty much as good or as bad as another.
And then we had the national building challenge in 2022 to quickly assess new technologies in areas like affordable housing.
The govt selected a set of startups and gave them one complex each to construct One such demonstration project was in Ranchi. 1008 two bhk flats in a G+7 construction to be built at Rs 15 lacs per apartment and completed in 15 months. It was mostly young iit startups that bid and won.
One iit alumni startup had an idea. What if they made one room at a time on the ground and hoisted it up for being fitted in the building. Here is how they did it:
The houses were completed in target cost as per target timeline. The issue now was sustainability and life of structure. This is where more work needs to be done.
Now fast forward to central vista in the heart of Lutyens Delhi. Similar challenges unlimited budgets. The very best of companies showed up to bid. They claimed they knew it all. This was India’s first pre cast cluster to be built in record time. There was no time to waste.
The end result was that “built fast” was not “build to last”. Whereas the affordable housing built by startups in far off Ranchi has no problem, the central vista has become a national embarrassment. The brand new buildings have surface cracks.
Why did this happen ? Technology !!! Materials science. Common sense.
Indian construction industry is still living in the 1950s of the developed world. The BIS standards are not upto date. We sought to complement BIS with a building technology council for new technologies but it doesn’t work as envisaged. The joints where the pre cast members meet the fly ash bricks open up because of thermal expansion and contraction (isn’t that known science?). The fly ash bricks are not autoclaved. When they dry, they shrink by a few millimetres.
The materials used themselves were not sustainable. Cement itself has a low life. It degrades with time – more so because of the pollution in Delhi. The right way out is to use next gen concrete (NGC). NGC is made from lime with activated fly ash and around 30% cement. graphene oxide flakes are added to improve setting. Vendors like JK Lakshmi cement now actually sell the LC3 cement. But this was not used. Aerated concrete panels are treated in a steam autoclave. these structures have minimal change because of drying. Best of all they absorb carbon dioxide and strengthen with time. These were not used either. Seems contractor didn’t have suitable equipment.
In around ten years, the central vista buildings will need to be made again.
It is time for tenders where contractors have to commit to life of building.