Houses off the shelf
Homes made of precast are aiding developers build faster and consumers get quicker access to their homes
Very little can shake or beat concrete’s thermal performance, storm resistance and sustainability qualities. A concrete home built with the proper supports can easily last for a long time to come and several generations. So it’s not surprising to know that more companies are looking at designing, engineering, manufacturing, and shipping precast concrete and encouraging developers to consider this as an option.
In the last one decade, precast construction has caught on so much that according to a market research report, the precast concrete industry, after overcoming the recession period, is expected to show a compound annual growth rate (CAGR) of 3.2% from 2016 to 2022 according to the latest study offered by DecisionDatabases.com. The global precast concrete market was $47.1 billion in the year 2015 and is targeted to hit $58.7 billion by 2022.
Prefabricated construction began in Europe after World War II and although it arrived in India in the 70s, it was not popular or there was little curiosity about it till a couple of decades back. The future of global construction is at its inventive beginning. John Von Neumann worked on what he called the universal constructor, a self-replicating machine that would operate in a cellular automata environment. Essentially, the concept is about a self replicating machine, a type of robot that is capable of autonomously remaking itself using raw materials found in the local environment. It’s not as far-fetched a concept as readers may imagine. Put 3D printing aside and look at more practical modern-day applications. Just look at Sweden’s Elematic company. Elematic is the leading supplier of precast concrete technology worldwide. It works in over 100 countries on six continents, supplying anything from a single machine to a production line to a complete precast plant.
Elematic precast systems are being used in the Middle East and India. Massive investments in precast manufacturing in these markets align with the challenges of needing to get more from less in markets which lack the skill base, but are exposed to rapidly rising labour and material costs. This need is prevalent in developed countries, but some of them are being held back by the barriers of status quo that is happy just to pass its costs on to customers and the community for as long as possible. In the free trade world now taking shape, however, these barriers will soon start to be pulled down.
In contrast to the in-situ concrete which is mixed, cast and cured on site, the precast concrete is a construction product which is produced by casting concrete in a reusable mold and cured in controlled environment at manufacturing units. The precast elements are then transported to the site and lifted into place.
This practice allows production of custom-designed precast concrete components like columns, solid slabs, hollow core slab, double T-slab, half slab, shell roofs, pre-stressed beams, retaining walls, wall panels, facades, staircases, window frames, etc. with variations in shape, size, surface finishes and colours. With the spectrum of creative possibilities in application and design along with dimensional accuracy, this technology provides abundance of choice for the architects and engineers to create unique and breakthrough buildings of exceptionally high quality. In addition, designers can easily plan future additions to buildings, because the precast concrete components can be rearranged.
Structures that will suit precast
For all the Economically Weaker Sections housing (G+3), LIG (S+ G+7 or 8) and MIG(S+ G+7 or 8) structures, precast is the best answer. For these types of structures, precast walls and precast slabs will make the structure stronger and durable too in the long run, and will resist lateral forces due to wind and earthquake effectively as strong shear wall type construction. In Telangana and Andhra Pradesh, the respective State governments are looking to construct affordable homes of two room units and precast is the best option for it. For this, with about, 7 to 8 tilting and fixed tables, costing approximately Rs 2 crore, walls and slabs could be cast and constructing about 300,000 sq-ft per year at a particular location can be easily achievable.
Makers of precast
Real estate developer Sobha Ltd has forayed into a new segment targeted at salaried professionals and nuclear families with the launch of ‘Sobha Dream Series’. The first project in the series, Sobha Dream Acres, is being implemented in Balagere, Bengaluru. With a total developable area of 10.26 million sq-ft, the project is spread over 81 acres. For this new segment, the company is planning to utilise precast technology as this will allow modular structures to be built and assembled with ease, by means of mechanisation and thus help reduce delivery timelines. The precast technology machinery is imported from Germany and Italy. “The execution of the project will be in-house.
Last year, Finland based precast machinery manufacturing and technology company Elematic announced plans to make India the manufacturing hub for Asian markets and is eyeing a revenue of around 7 million ($7.84 million) from the country operations in the current financial year. The company is mainly working with Indian construction companies and has also set up a manufacturing unit in Allahabad this year to produce steel structures used for casting. Elematic, founded in 1959, is present in more than 100 countries, across five continents, with a total revenue of 75,100,000 (2014).
Recently, BN Precast Pvt. Ltd. acquired the first Acotec line in India. BN Precast is an Indian pioneer in using Acotec technology to manufacture non-load bearing concrete hollow-core walls under its own Walltec brand. Automated production process Acotec walls are suitable for use in several environments. They are mostly used as internal partition walls in residential, commercial, institutional, and industrial buildings. BN Precast’s walls are currently being installed in all of these building types as well as sheds. Acotec walls are also a good choice as a boundary or compound walls or for use as an anti-noise screen.
Environmental conditions may be challenging for the construction industry due to factors such as seismic activity or rainy seasons. Precast elements are manufactured in a factory environment and the negative effects of weather conditions can be eliminated. The walls are proven to work in countries with the strictest standards and requirements for seismicity, moisture, and fire resistance.
With an annual growth rate trend of 2.7%, it is estimated that the India’s population will be standing at about 1,200 million marks by the end of 2014. Sizable of this population is below the poverty line and lack basic human needs. They do not have proper housing accommodation. Many live in slums and some have shared accommodation. Housing is a basic need and like any basic human need will be constantly in demand. The gap between available housing stock and that required is ever increasing. The potential for housing in this country is huge. NHB estimates that the housing shortage at the beginning of the 12th Plan is 18.90mn units, bulk of which, say 18M units, are in the EWS and LGH sectors.
Mass housing targets can be achieved by replacing the conventional methods of planning and executing building operation to suit the special and individual common needs optimally using the locally available materials and even rationally utilizing other new/ make shift/substitute resource materials. Partial prefabrication is an approach towards the above operation under controlled conditions. The essence lies in the systematic approach in building methodology and not necessarily particular construction type or design. The methodology for low cost housing has to be of intermediate type-less sophisticated involving less capital investment.
The instant answer or ready solution to this gargantuan plan is to go in for innovative compliant precast technology tailored to suit situation specific requirements and easily adaptable to the location, making optimum use of the locally available construction materials and the transport facilities.