While a majority of Indian structures both residential, commercial and infrastructure are being built the cast in place or in-situ mode, there is a growing popularity for precast technology within the Indian construction community. Precast construction technology is not new in India. It has been adopted in India from past many years, but was mostly limited to civil structures such as tunnels, bridges& flyovers and underpasses. However, until a decade back adoption of modern and innovative construction technology and practices by the Indian realty sector was slow and therefore precast , though widely used across the globe for its inherent advantages, did not catch the fancy of the industry.
Today, with critical housing shortages, rising labour and input costs and an in-creased emphasis on quality and timely delivery, more and more developers are opting for innovative construction practices like precast.
Rising Popularity of Precast
According to industry experts, apart from certain countries in Asia-Pacific, the rest of the world is increasingly using precast as their mode of construction in a majority of projects. The construction industry in India is around USD 500 million and precast has only 2% share vis-à-vis the traditional method of construction. However, a gradual shift is occurring and precast building technology is rapidly gaining a foothold in the Indian market and primary among them is the need for affordable housing.
The speed of urbanization poses an unprecedented challenge for the construction industry. The 12th Plan Working Group on Financing Urban Infrastructure estimated the urban housing shortage in the country at about 29 million units. The demand for affordable housing is likely to rise from 25 million households to more than 38 million units by 2030, by when the urban population is likely to surge to 600 million. Poverty, the sheer scale of population growth and the huge rates of urbanisation as people move from the countryside into the cities will add to the housing shortages.
The application of precast concrete structural systems have been attaining vast progress worldwide and is being used in countries like Singapore, Malaysia, Indonesia, Phillipines and countries in Africa which are also facing similar issues. This is due to the fact that the precast structural systems possess several advantages compared to conventional cast-in-situ concrete systems, such as quality control, speedy construction, and suitable application to regularly modular systems.The best part of the technology is that it not only speeds up construction work but also enhances the quality of the final output. It has also passed rigorous safety standard around the world for seismic and structural testing as well as fire safety, and is environmentally sound. The use of this technology can bring down the construction cost by 10-15 % and it could be the answer to India’s affordable housing.
The government bodies also seem to be realizing this as last year, in the Vibrant Gujarat Summit 2013,global players like Elematic of Finland and Spiroll Precast Services Ltd of the US signed MoUs for Rs. 15,000 crore and Rs. 5,000 crore, respectively in order to provide precast technology in cost-effective and efficient housing construction within the State. Spirollis working with Indian partners Apollo Infratech to help enable investors to meet the expected boom in demand for mass affordable housing, not just in Gujarat but across India.
More and more private real estate developers are also favoring precast be-cause of its advantages compared to other building techniques. The schedules are always tight in the construction business and precast makes it easier to stick to project timelines and eliminate unexpected interruptions in work. Precast structures also do not require finishing, like plastering or wall putty. Though more expensive than the conventional method, precast helps put buildings together more quickly. India is also facing a shortage of skilled labor in the building industry. Labour and material have increased by 20 per cent since 2010. And since precast is less labour-intensive, several contractors and developers have been embracing this technology.
In general, there are three broad categories of use for precast concrete, namely components, panels & volumetric. However, currently the residential building market in the India is taking advantage of just the first of these options. Whilst companies have studied the potential for panelized or volumetric precast in their designs for houses, the most popular use for precast concrete, however, is in components. This includes walls, beams, floors, columns, panels, & stairs. The potential to widen the market for precast into these areas is significant.
There are some perceptions that precast construction is inflexible with respect to changes and upkeep of the work. Precast concrete buildings previously had an identifiable appearance. However, with advances in technology and technique, precast buildings are now indistinguishable from those constructed using non-precast methods. Designers no longer work within tight constraints. Increasingly, the situation is that precasters are able to accommodate greater variety and complexity, effectively designing their elements to meet design requirements. Continuous investment and innovations have transformed the precast industry so that complex plan layouts and external treatments can now be accommodated. Curved precast panels with a variety of highly attractive and durable finishes can be manufactured to meet the most challenging design requirements. Precast construction is virtually unlimited in its application and is suitable for single and multi storey construction.
The most common error is to take an ‘all precast or no precast approach’ to design. In fact, a key issue for designers is to identify which construction method, or mix of construction methods and materials is most appropriate for the specific requirements of the building. The most economical solution might well consist of a mix of cast in situ and factory assembled units.
One of the reasons cited for the low popularity of precast is that India’s road network is still not highly developed and trucking precast components over very long distances is impractical. In such scenarios, site casting or tilt-up form of precast construction can be used.
Although precast being costlier, most tend to overlook the tangible benefits it offers in terms of time saved and high consistent quality delivered with the finished product. Also while the initial capital cost of opting for precast method for construction may be high as against conventional way of constructing a building, in large commercial buildings, this method can save up to 40 per cent of the energy costs. The high density of precast concrete can act as a thermal sink to provide year-round comfort and reductions in energy use. When insulation is combined into a precast concrete sandwich panel, the best of both worlds is achieved. The combination of high thermal mass and insulation results in significant energy-saving benefits in all climates. In the case of residential buildings, home buyers will get a larger carpet area, since precast walls are thinner, compared with conventional brick walls.
Some in the community believe that precast construction technology demands highly skilled labour with more machinery skills and installation of precast elements is a very difficult task which demands enhanced skills and know how. Lack of structural engineers and qualified contractors in precast is cited as another reason for the low number of precast projects across country.
There are also concerns on performance of precast concrete construction in highly seismic areas. Indian standards of construction on precast concrete provide recommendations for most of the preliminary issues to be considered while designing a precast structure. But there are some issues in seismic design of precast concrete structures that still need immediate attention. But with the infrastructure growing like never before and the demand for faster, innovative and safer construction options, it is high time that Indian standards look into the seismic design provisions of precast concrete systems in detail.
Despite being a nascent industry in India, this segment is witnessing increased activity and entry by various players. Several players are entering the market and establish themselves early on as it is expected that precast will become an inevitable part of the Indian construction in the future.
Precast manufacturers have a critical role to play in the proper planning and execution of precast buildings. Involving the precaster at the early design stage is the best way to achieve the most economical building solution. Early involvement also allows the manufacturer to schedule production so as to maximize cost savings brought about by the use of standardized components and early completion. Manufacturers and critical solution providers who have established their presence in precast incluxzlayers in this sector are now looking to increase their capacity at their existing set-ups and then move to establish other plants.
In order to strengthen the position of precast, companies are also employing different strategies to address the concerns related to precast. For instance, Peikko, a well-established precast manufacturer, is carrying out its seismic investigations on joints and connections of precast members in a highly seismic zone in India. The structural behaviour of a precast concrete system is greatly different from that of a comparable monolithic cast-in-place system. The main structural difference between cast-in-place buildings and precast buildings lies in their structural continuity. The structural continuity of conventional cast-in-place buildings is inherent while in the precast systems, members should be assembled and connected to produce a structural system capable of resisting gravity loads as well as the lateral forces due to wind or earthquake. Connections are the most crucial part in precast structures. The challenge in designing precast systems is to find an economical and practical method to connect the members with adequate strength and ductility for the earthquake loading. The behaviour of the structure mostly depends on the behaviour of connections. Peikko plans to release a booklet soon on the subject of behavior of precast in highly seismic zones for the benefit of its clients.
Malar Infra can provide its clients with a complete mobile precast factory setup. By setting the production plant at the project site, it can eliminate the overheads related to excise duty and transport, thus reducing overall costs for its clients.
Precast India Infrastructures, Malar Infra, Tata Realty and Teemage Precast to name a few are actively involved in large scale affordable housing projects in different regions of the country. Malar Infra a Precast Turnkey Solution provider has identified 15 locations all over South India for developing townships using precast technology.
Managing Director of Precast India Infrastructures, Ajit Bhate believes in getting internally a strong foothold on basic constraints of precast technology such as structural design and analysis, production methodology, quality controls, good planning and monitoring of products / elements, technically correcting matters regarding testing of elements. In lifting insert positions, safe installation, developing of internal resources like automatic production machinery for various items, mechanisations, handling equipments like tower cranes etc,. The company has completed and delivered around 3 million sft of RCC prefabricated structural cold shells in the last two years. It is currently working on projects such the Cummins India Tech Centre (Rs. 180 crore project with different precast elements), World Trade Centre (around 2.5 million square feet), Ritz Carlton Hotel (around 1.5 lakh squarefeet; it is part precast) and Cummins India Corporate office (0.7 million square feet). The company’s clientele also include Schmersal India, Raymond and Panchshil Realty.
Teemage has completed about 30 projects worth around 10 lakh square feet in the past 2 years and has around 5-6 projects worth about 4 lakh square feet in the pipeline. Most of the projects are commercial while a very few are residential. Since it has been receiving enquiries from places where it is too far to transport precast, the company is contemplating putting up a site precasting yard in those places. The company regularly conducts technical sessions about precast in order to educate architects and engineers. It hires unskilled labour and provides them with rigorous training specific to precast.
Construction conglomerates L&T and Shapporji Pallonji have dedicated divisions for precast. Developers Amrapali, Supertech and Brigade have also established their own precast plants for their projects.
MNCs like Elematic, Weckenmann and Spiroll have been supplying Indian companies with technology for production of precast concrete components through state of art machines and systems enabling them to set up their factories. However, the industry still has some divided views on the necessity of such extensive setups in plants when there is not sufficient scale for efficient operation of the same.
There are also companies in India which provide technical services such as engineering design, drafting & consulting specific to precast concrete such as Precision Precast, TRC and Van Boxsel. Halfen provides support systems for precast components.
Developers like Amrapali and Super-tech have established their own precast factories at Greater Noida. Amrapali’s factory will manufacture custom designed precast concrete components like roof slabs, beams, columns, wall panels which offer flexibility in shape and size with a variety of surface finishes and colors.
In Delhi NCR – Ghaziabad, BCC Infrastructures is developing a huge township where precast concrete elements of wall panels, lattice girder half slabs, staircases and balconies will be produced at site factory to erect high rise residential towers. Phase 1 of the project was built using classic construction methods with in-situ cast concrete floors and interior and exterior walls of brick. Due to increasing pressure on time frames and schedules, the company adopted the precast method as against the traditional construction methods to carry out the entire Bharat City real estate major project.
L&T’s Pragati in Bhoiwada, Parel, Mumbai is a G+23 storeys fully precast residential building project consisting of 6 towers to rehabilitate slum dwellers. Larsen & Toubro (L&T) took the challenge of using Precast Technology for the 24 storeyed residential towers using precast large wall panel system in seismic zone -3 in Mumbai. Substructure was pile foundation and ground floors of all towers were cast by conventional construction. Super structure consisted of precast large wall panel system. All elements were cast in yard and transported to site by trailers and installed at site by the use of tower cranes. After placing the elements in position, they were grouted with non shrink, non metallic grout with necessary rebars in the precast members.
Down south, Brigade and Purvankara have also introduced precast technology in their projects. BCV Developers Pvt. Ltd., a Joint Venture between Brigade Enterprises Ltd. and Classic Group and Valmark Group, has introduced precast concrete technology for residential apartments. This technology will be incorporated in commercial properties as well at a later stage. The technology will initially be implemented in the 130 acre Brigade Orchards mixed-use development in Devanahalli, near Bangalore airport. Brigade Group’s precast plant at Brigade Orchids in Devanahalli has been setup with equipment imported from Italy, Germany and Singapore and is manned by a team of experts who have extensive experience and have worked in the precast industry in India and Middle East. With the present capacity being up to a total volume of 70-100cubic meter per day, Brigade Group plans to erect the shell for two apartments on a daily basis.
Purvankara’s project Provident Sun-worth has also been built with precast technology.
Need for Standardization and R&D
At present, there is no regulatory body but the Precast Concrete Engineers Society (PSEI) is mulling over the establishment of a Self-Regulatory Organization. A regulatory organization dedicated to expanding the use of quality precast concrete and providing members with the technical support, educational opportunities, certification programs and informational resources should increase the adoption of precast concrete in the country. Also, because of the relatively low magnitude of such construction being used in India, there has been an absence of up-dates on standards of precast concrete. Establishing industry-wide standards of design and production of precast concrete will increase confidence among the end-users and contractors.
Universities and educational institutions should also dedicate a part of their curriculum towards precast concrete. One such initiative is MoU agreement with Manipal University signed by the Faizal and Shabana Foundation, part of KEF Holdings to invest Rs. 5 Crores towards a research and development facility for precast concrete technology at Manipal Institute of Technology (MIT), India. The agreement will also introduce a precast design and engineering course to the University’s curriculum. The Foundation aims to further precast technology by introducing it to students to advance the field and create employment opportunities for them.KEF Holdings recently entered a partnership with Finland-based Elematic, a leading provider for precast technology and machinery to set up manufacturing plants in India-and later UAE- involving investments totaling Rs. 300 crores.
There is no doubt that the future of the construction industry lies in the precast segment. There would be no looking back for the industry once standardization, acceptance and awareness are in place.