Photo Courtesy: MORPHEDOPrecast providers are coming up with a slew of innovative applications. CW takes a closer look. Highways and roads In highway projects involving flyovers, bridges, overbridges, underpasses and overpasses, many RCC structures are being done in precast, including segmental box girders or U-girders, piers and pier caps in the case of RRTS and MRTS projects, says Debashish Roy, CEO, Vollert India. “Underpasses or subways that are more like underground tunnels are being done in precast, which was not the situation a few years back. A precast concrete structure for underpasses can be an open-end box section, portal frame segments or separate wall and roof units.” Highway developers use high-end machinery to speedily and smoothly build roads but they struggle to develop small structures for amenities like kiosks, toilets and administrative blocks, which every contractor has to complete prior to the final handover, adds Ronak Dhoot, Founder & CEO, BLOKS Precast. To tide over this challenge, BLOKS Precast can build all the amenity structures for road projects in precast. The company has done so for a road project being implemented by GR Infra in Andhra Pradesh. “We have also supplied U-drains to road developers, which they find convenient because the components are ready to be installed as soon as you have excavated the area,” he adds. “We are also looking at supplying components for the periphery walls of highway projects.” Buildings and parks There is also huge demand for precast nowadays for industrial and commercial buildings, factories, warehouses and energy projects, continues Roy. “A lot of structures like columns, beams, slabs and double tees are done in precast.” In the real-estate sector, especially for affordable housing projects where the units are small (360 sq ft/500 sq ft), he reports huge demand for precast pods (called prefabricated prefinished volumetric construction) for kitchens and bathrooms. Many contractors are now turning their attention to these pods for speeding up construction and reducing the chances of leakages in wet areas. Staircases is another area with possibilities in precast. “Slabs and walls get done rapidly but the construction of staircases is one of the most tedious and time-consuming parts of projects,” says Dhoot. To speed up this job, BLOKS Precast has supplied precast staircases for Godrej Forest Grove, Mamurdi (Pune). “We have supplied precast components like solid boundary walls and stormwater drains for logistic park and industrial park projects of multinational e-commerce companies,” he adds. Bright future Talking of some potential applications of precast, Roy says, “In the residential sector, precast sandwich wall panels may possibly find greater use in offices, schools, apartments, townhouses and condominiums for being an excellent noise barrier.” As for the rail sector, with more MRTS/RRTS projects and bullet train corridors coming up, Roy believes precast will definitely be at the forefront. Unlike the ballasted railway system across India, the Mumbai-Ahmedabad high-speed rail, which will touch speeds above 300 km/hour, will have a ballast-less track, observes Roy. “The ballast-less track will have a concrete base slab and then a precast track slab. Other precast structures will include noise barrier walls and possibly signalling ducts.” Driving adoption To speed up the adoption curve as well as the implementation of projects in precast, Dhoot feels the Government should specify precast components such as boundary walls, stormwater trenches and culverts in tenders. What has also helped boost the precast industry in Europe is the standardised layout of buildings in those countries. “Standardised layouts make it easier for manufacturers of precast elements to provide these at competitive prices,” observes Dhoot. “Also, overseas, architects themselves are suggesting the use of precast to clients.” In contrast, architects and developers in India are still reluctant to adopt precast, he believes. “Precast technology hasn’t been adopted much in Maharashtra but Hyderabad and Bengaluru have seen a lot of precast construction. Even buildings of 24-36 floors are being done in precast by developers such as the Brigade Group, Sobha, Tata Housing and Aurobindo Reality. But these are still few in number and much of the architect-developer community isn’t exposed to what’s happening and what’s possible. Precast technology is being adopted the most in areas where labour is scarce.” Indeed, labour scarcity is behind the growing adoption of precast technology. In fact, in the past couple of years, many developers and government authorities have been facing labour shortages, especially for infrastructure projects, most of which are in remote areas, continues Dhoot. “With time becoming a priority for most projects, clients are increasingly looking for offsite construction options wherein the components are manufactured elsewhere and transported to site for installation.” With much of India’s construction labour force coming from Uttar Pradesh, where a lot of infrastructure projects are getting underway, he expects the labour scarcity in other parts of India to intensify in a couple of years. Labour will prefer working at sites closer home. Then, precast technology will become a preferred option and slowly and steadily the construction industry will get the status of manufacturing. Precast is a harbinger of the construction shop floor! Infra development brightens cement prospects What sort of R&D is happening in the cement industry? India is the second-largest producer of cement in the world, accounting for more than 7 per cent of global installed capacity, according to ResearchAndMarkets.com. Domestic production dropped 12 per cent to 294.40 million tonne (mt) in FY 2021, no thanks to the pandemic. That said, the consumption of cement is expected to touch 419.92 mt in FY2027. So far, the housing sector has been the major contributor to the growth of the cement industry, accounting for 60 per cent of cement sales. However, ResearchAndMarkets.com reports that demand is further being fuelled by the non-trade segment, which is gaining momentum with the resumption of construction work of public infrastructure projects such as roadways and metros after the lockdown. Industry voices confirm this finding. While the Pradhan Minister Awas Yojana (PMAY) scheme and easy housing loan schemes are major drivers in the individual house builder segment, the huge allocation for infra is driving a pickup in demand for cement from infra of late, according to Ramesh Barath, Senior General Manager (Brand Management), Ramco Cements. Increased government spending, particularly in the infrastructure space, is spurring renewed demand for cement especially for infrastructure projects across the country, shares Rajeev Nambiar, CEO and Managing Director, Shree Digvijay Cement. Innovations in cement With an increased focus on carbon neutrality, Shree Digvijay Cement has developed a new product under its blended cement portfolio. “It is a premium product combining strength and durability, which paves the way for a reduced carbon footprint,” explains Nambiar. At Ramco Cements, R&D aims at solving some of the most common challenges relating to cement faced by the construction industry and infrastructure developers, such as chemical admixture compatibility, the occurrence of cracks, leakages and dampness in concrete structures. For instance, Ramco Supercrete gains strength quicker than other cements and offers crack-free concrete. Ramco Supergrade is the trendsetter blended cement offering higher durability owing to the low heat of hydration and lower free lime content. Other products suit different purposes, including concreting, plastering, high slump retention, precast applications, etc. “More than just selling cement, we believe we must devise solutions to the challenges faced by construction professionals,” says Barath. Studies using Ramco products and M-sand show excellent results, meaning the cement is compatible with M-sand wherever river sand availability is a constraint. Of course, Barath cautions, “The quality of M-sand varies and it is very important for users to select the right type with proper gradation to make good-quality concrete.” Not surprisingly, he has seen a substantial jump in the sales of Ramco Supercrete, “in areas where quality is preferred over price”. Our fastest-moving product segment continues to be ordinary Portland cement (OPC) along with blended cement, adds Nambiar. “This can also be region-specific.” The more extensive use of cement bodes well for the industry. Will concrete 3D printers change how buildings are constructed? Advancements in the capability of concrete 3D printers augur well for the wider adoption of the technology. What are 3D concrete printers capable of? Constum, a concrete 3D printer from Morphedo, is suitable for constructing G+1 houses on sites of up to 1,200 sq ft and concrete structures like defence bunkers and shelters, furniture, sculptures and facades, concrete art, concrete components in parks, trenches, bridges and so on, says Sushil Baranwal, Founder, Morphedo. “Constum would be of use to both real-estate developers and infrastructure developers looking at an efficient, automated solution.” “A 3D concrete printer from Deltasys E Forming is suited to the construction of affordable housing in low-income countries, military bunkers in remote regions and complex construction where the formwork is difficult to manufacture,” says Virendra Kadam, Founder and CEO, Deltasys E Forming, a developer and manufacturer of 3D printing machines. Why would a developer think of printing a building? “The cost of construction is highly dependent on the type of project but, on average, we have seen that our concrete 3D printing technology ‘constructs’ at around 45 per cent less than traditional ways of construction,” shares Baranwal. The technology also provides flexibility in customising the design of the architecture. “Our 3D printer reduces the time to build by 70 per cent, reduces the cost of labour by 60-80 per cent and minimises construction waste by 30-60 per cent compared to traditional construction technology,” explains Kadam. He adds that important performance indexes of the printed concrete, including workability, setting and hardening time and mechanical properties, can be optimised by the selection of materials and printing parameters. If that’s inspiring, here’s how the technology works. “3D printed concrete is deposited layer by layer without any formwork support and vibration process,” says Kadam. “Larger structures are printed in sections and then assembled on site,” explains Baranwal, speaking of Constum. 3D printing is gradually picking up steam, judging from the 500-plus machines Deltasys E Forming has installed across India. These use polymer, composite, metal, clay and concrete as the printing ‘ink’. A concrete 3D printer of 10 cu m size is next on the anvil, with the capacity to build up to a two-storey building, shares Kadam. “As the machine will be modular, it can be extended to build up to a five-storey building.” Printing a five-storey building? That’s quite a tall order!