It's fast and facilitates better construction. Still, the adoption of precast technology is growing only gradually. That said, a few companies such as Precast India Infrastructures, Brigade Group, BCC Infra, Godrej Properties, Tata Housing and Sobha have adopted precast technology, some for key projects.
'We are building Dream Acres in Bengaluru, one of Sobha's biggest projects, entirely with precast technology, which has helped us improve the rate of delivery vis-a-vis the traditional route,' says JC Sharma, Vice Chairman & Managing Director, Sobha.
Best fit for luxury and affordable housing
About 80 per cent of the precast building market is taken up by large companies engaged in mass housing, government-sponsored projects, such as BG Shirke, KEF Infra, Teemage Precast and VME Precast, estimates Gyasuddin Siddiqui, Business Development Manager, StruEngineers India.
Precast technologies and elements are ideal for the construction of large volumes of small, compact-size apartments to achieve the shortfall in affordable housing, observes Suhas Mohol, Director, StruEngineers India.
In the luxury segment, precast technologies and elements have been used only for villas, not high-rise buildings.
Interestingly, the affordable and luxury segments use the same precast elements.
"Subject to design, the civil work expenditure of a luxury building is on a par with an affordable building," says Chetan N Shah, Director, Simplex Prefab Infrastructure India.
As long as the precast element used for the luxury project and the affordable project is made from the same grade of concrete, preferably M40, they are the same, says Mohol.
Gaps in the elements market
Asked to list the most useful precast elements, Abhay Chordia, Joint Managing Director, Panchshil Realty, cites hollow core slabs and beams and lightweight AAC blocks, all for ensuring speedy construction.
"Precast concrete panels, which are assembled at site to required dimensions, and precast (solid or hollow) blocks are some of the popular precast elements," adds Anil Kumar Pillai, Senior Deputy General Manager, Technical Services, The RAMCO Cements. "Ramco offers Super-Fast, a rapid hardening Portland cement, which as per IS 8041, is suitable for such precast work."
However, the general consensus seems to be that "India's precast element market has yet to develop," to quote Ajit Bhate, Managing Director, Precast India Infrastructures.
Precast elements of different sizes are still largely made to order and are not readily available in small or large quantity, says Siddiqui, based on his recent market experience of sourcing a small number of 200-mm hollow core slab elements for a mock project in Nasik.
Precast India Infrastructures produces precast elements for the industrial, commercial, and institutional building projects it takes on; however, Bhate observes that many of these elements are missing from the Indian market. "Walls and columns are commonly available but we also use V beams, pre-stressed beams and rafters, H-cross sections, special lightweight beams, lightweight double-T beams, etc, and imported moulds such as self-reactive moulds and other state-of-the-art equipment sourced from Germany, Italy, Denmark, etc," he adds.
Infosys Multi-Level Car Park, a project by Precast India Infrastructures driven by the concept of 'sustainability', was nominated as one of the world's best 13 transportation projects by the World Architecture Forum and presented at the Berlin's 2017 forum.
"It consisted of unusual precast elements such as 16-m double-T slabs and intricately designed façades enveloping the entire building,' says Bhate.
Precast façade panels and precast staircases are missing from the market, according to Chordia.
Towards greater adoption
Innovations in the elements market are welcome.
At Panchshil Towers, Kharadi, Panchshil Realty has introduced 'The BathPods', a three-dimensional self-supporting structure prefabricated offsite, featuring a floor base frame, walls and ceiling, and delivered onsite complete with all architectural fittings and fixtures.
"With The BathPods, we are looking at transforming the construction of bathrooms and washrooms in medium and large-sized real estate, both in the luxury and affordable segments," says Chordia. "At Panchshil Towers, we have saved a fifth of the construction time, about four to five months, by making use of prefabricated bathrooms."
To help individual home builders adopt precast technology, the availability of smaller precast elements in smaller towns and cities must be improved, but with strict control over quality by introducing an ISI mark for these, suggests Prashant Varma, Director, Nandadeep Precast Prestressed Concrete.
Varma suggests reviving an old government initiative, district-level outlets (called 'Building Centres'), providing precast elements at controlled prices, along with training engineers to use these elements.
"If the government is serious about housing for the masses, it must also reduce the taxes on precast," Varma says.
"Precast elements are currently subject to 18 per cent tax plus the applicable cost of transportation. Despite this imposition, precast construction compares to cast-in-situ construction, which speaks volumes about its potential."
As the precast industry matures, early adopters of the technology are also adopting methods to ensure that construction proceeds smoothly and the supply of elements is uninterrupted.
Chordia suggests ensuring that the supply of precast elements is through a bulker and storing the elements in a readymade silo. Keeping extra stock ensures cost-effective convenient operations.
Associated technologies and construction accessories are also entering the market.
Siddique cites the growing availability of lifting systems for elements, wire loop boxes, connecting systems, prop-supporting anchors, etc.
Proper lifting systems will displace the rudimentary hooks and bars that companies were using to put elements in place, and thus, help improve the quality and outcomes of precast construction by reducing the possibility of damage to the elements before positioning and onsite accidents, says Siddiqui. Among the global companies offering technologies in India, he counts Hilti, R-Steel, Peikko Group, Halfen-Moment Group and Oracle Buildcon.
StruEngineers India offers companies using precast technology Swedish software IMPACT to assist design and detailing functions and project management.
For precast element providers looking to increase their capacity and improve efficiencies, Moldtech (a supplier of moulds and precast plant equipment since 1986 but new to India) has launched the 'Giraffe', a self-propelled equipment for the transport and pouring of concrete from the batching plant into the moulds.
According to Angel Cejudo, CEO, Moldtech, 'The Giraffe solves the problem of logistics in precast plants, where the concrete mixer is far from the moulds or shared with other uses, such as ready-mix concrete, or where a direct connection cannot be established between the discharge of the concrete production plant and transport hoppers or flying buckets, towards the moulds and precast element production equipment.'
Being self-propelled, the Giraffe eliminates the need for a gantry crane plus operator and speeds up operations, which is critical to achieve scale.
Growing opportunities in precast are also attracting strong cement and ready-mix concrete players such as LafargeHolcim India."On a global scale, the company proposes to execute more aggressive strategies for aggregates and ready-mix concrete and build a fourth business segment, Solutions & Products, to take advantage of products and applications that are closer to the customer. The Solutions & Products segment, which currently includes precast, concrete products, asphalt, mortars and contracting and services, already generates annual net sales of CHF 2.1 billion," says Jan Jenisch, Group CEO of LafargeHolcim.
Gain a Price Advantage from Precast
Precast was conceptually born out of standardised construction. Replicating a design allows structural elements to be mass produced in a carefully controlled environment; this, in turn, introduces cost-efficiencies.
Using large quantities of standardised precast elements would ensure steady pricing that is akin to conventional construction, says Chetan N Shah, Director, Simplex Prefab Infrastructure India, a company offering consistently composed, superior quality stairs, load-bearing walls and non load-bearing walls, and roof elements.
Shah recommends that large precast users enter into a pricing agreement, wherein the cement and steel is a variable component, and the balance is a fixed component.
Cement in India: Bright Prospects
The medium and long-term outlook on cement is positive in India, the world's second biggest cement market. Demand is expected to rise on the back of the government's higher budgetary allocation to affordable housing and infrastructure and improved macro indicators.
With forecasts of continued high growth rates, companies are on an expansion spree. To further strengthen its footprint in India and reinforce its leading building materials position, LafargeHolcim, through its subsidiary Ambuja Cement, will invest CHF 200 million in a new cement plant in Rajasthan, with a clinker capacity of 3.1 million tonne per year. When the plant becomes operational in 2020, it will serve customers in the North, including Delhi.
After taking over Murli Cement in late 2017 and Kalyanpur Cement in January 2018, Dalmia Bharat is considering acquiring Binani Cement to strengthen its footprint in the North, gain a pan-India presence, and significantly raise its installed cement capacity from the current 25 million tonne.
Dalmia Bharat Cement will also gain an edge over other cement manufacturing companies through Binani's limestone reserves of 378 million tonne. 'Control over the supply of a key raw material is critical for cost control at a time when the variable cost on per tonne basis has increased significantly owing to increased petcoke and slag costs,' says Mahendra Singhi, Group CEO, Dalmia Cement (Bharat).
Among key trends in demand, Anil Kumar Pillai, Senior Deputy General Manager, Technical Services, The RAMCO Cements, identifies greater awareness and usage of blended cements especially Portland Pozzolana cement, which lowers the heat of hydration and increases ultimate concrete compressive strength, thus enhancing the durability of concrete structures.
Challenges to the consumption of cement include the scarcity of river sand (or fine aggregates) in some states, which hits individual home builders the most owing to the limited availability of alternatives like properly graded manufactured sand or crushed stone sand, notes Pillai.
Impact of Design on Precast
Precast technology is flexible and adaptable to a large range of designs, says Ajit Bhate, Managing Director, Precast India Infrastructures.
While the sizes of the members can be the same as in conventional construction, subject to the transport-ability, the connections between the elements become critical in precast structures, more so in seismically active areas, because members are not cast together, says Bhate.
Architects designing structures that will be built using precast elements should follow modular sizes, suggests Prashant Varma, Director, Nandadeep Precast Prestressed Concrete.
For example, precast lintels are manufactured in multiples of 300-mm span, so it helps if openings are in multiples of 300.
- Charu bahri
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