Precast is the preferred choice for construction of Metro stations

Onsite casting hinders the flow of the traffic. By using the offsite casting elements and erection process, construction of metro stations is being catalysed says Shridhar CN, Head – Technical & Marketing, Preca Solutions India Pvt Ltd.

How is precast concrete helping in the construction of Metro projects?
Almost all Metro projects in India are being constructed using precast technology. As metro projects run through interiors of the city and the elevated bridges are on existing active traffic roads, onsite casting can hinder the flow of the traffic. The use of offsite casting elements and erection process, it is easing the traffic situation. As all the elements are being cast at the factory, the construction work will progress faster on a high priority basis and projects will also be ready at the earliest.

What kind of different techniques are being used while executing Metro Projects?
In Metro construction, all pillars are cast using onsite casting because of huge weight and sections. The track segments are cast as precast and erected on-site. Once the segments are erected, the post tensioning process takes place and once post tensioning is done, all the grouting work is looked at. After that, the track laying and grouting work is completed  and stations are constructed using cast in situ or precast methodology.

How much precast concrete helps in the construction process vis a vis site-cast?
Precast construction helps in slashing construction time by 60 to 70 per cent as compared to site cast construction process. Precast construction reduces pollution, no plastering is required on precast elements, also no on-site curing is required. By avoiding site curing, the wastage of water is reduced.

What are the cost benefits and advantages of using precast concrete?
If there is symmetry in elements, precast cost will be at par with site cast costing. Even big volumes with typical elements will work out further economically. The advantages of using precast elements are that the construction is speedy, no plastering is required, and it is durable because of high grade of concrete and well compaction. And other benefits include zero curing at construction site besides which all the precast products are green and environmentally friendly. 

What is the market opportunity to precast concrete solutions in India?
The present market is booming for the precast concrete sector. Precast will be in more demand once the lockdown ends. Because the market is facing shutdown and after it lifts, suddenly requirements will also increase.

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