S. J. Vijay, Chairman, Salmon Leap Associates India
Unlike other industries, the Construction Industry has been stagnant and slow to adopt new technologies and has never undergone a major transformation. As a result, productivity has stagnated over the years, or in some cases, even declined. The image below depicts the evolution of the Construction Industry
The construction industry is buoyed by predicted growth and expansion, however, it continues to underperform in four strategic areas: Productivity, Certainty in Delivery, Skills Shortage, and Data Transparency. Poor productivity and project uncertainty can be countered by introducing technology into construction. The right technology would ensure reduction in the project development cycle and reduction in labour.
Construction Industry Globally
Smaller but advanced countries like Singapore as well as larger but thinly populated continents like Australia have been developing and deploying construction technologies and methodologies for decades. These have been tried, tested and proven, and can be the solution to the challenges faced in housing for the billion+ Indians.
Construction of the built environment has continually been adopting “increasing levels of manufacturing” as the solution to address the challenges relating to:
- Speed of Construction
- Quality of Construction
- Reduction in Wastage
- Productivity in Construction
- Dwindling number of Construction Workers/ Labourers
- Health Safety and Environment Issues of Construction
- Efficiency of Resources in Construction
Indian Construction Industry
The surging construction activity in Infrastructure and Buildings coupled with rapidly diminishing labour pool has already pushed the leading players to adopt mechanized and precast methods of construction, be it for bridges or flyovers or metros or even roads, canals, waterlines, airports, seaports et al.
Formwork-based cast-insitu construction while accelerating the speed of building has also increased demand of skilled labour, and safety issues of handling the formwork at increasing height by the multitude of workers.
In July 2017, the Prime Minister of India also directed the use of 3D Technology to speed up housing construction in India. India needs the highest number of houses of possibly at the lowest price point and also in the shortest timeframe.
India has increasingly been adopting different levels of machine-driven construction. The cast-insitu construction using conventional and newer formworks is being replaced by offsite manufacturing / precast of the elements of the built environment as 2D or planar elements. As shown in the diagram above, India by doing this would still be stuck in Stage 3 of the construction evolution.
Stage 3 of construction should be by manufacturing the houses not as components, not as just 2D elements but as modules that deliver a room or more from each precast as 3-Dimensional Monolithic Modular Volumetric Precast. Construction Methods Currently Prevalent in India
Indian construction activity has increasingly been moving away from conventional column, beam, slab-based construction to formwork-based cast insitu shear wall construction during the past decade. The newer types of skills required to efficiently execute the formwork-based construction be it with MIVAN or with ALUFORM or with JUMPFORM or with TUNNEL FORM have all been struggling to cope with the rapidly diminishing quantity of construction workers and more so by the miniscule of fitters and formwork handling workforce.
A spurt in Affordable and other Social Housing requirements have led to the developers establishing their own 2D Precast Panel Production facilities as captive plants in Delhi, NCR, Bangalore and a few other cities.
Third Party manufacturers of 2D Precast Panels in the offsite factories are transporting a multitude of panels to building sites and erecting them with equipment and a large number of installation crew in Bangalore, Hyderabad, Vizag, Gurgaon, Mumbai, Pune etc.
Most of these 2D plants are designed and configured to Precast Columns, Beams, Hollow Core or Solid Slabs and Wall Panels as disparate elements in the dimensions of Commercial, Retail and Institutional Buildings as well as Multi Level Car Parking facilities.
However, offsite production of 2D elements, their transportation to building sites, erecting them, aligning them for plum and level, jointing the multiple pieces to secure the targeted strength and shape, and sealing the numerous joints, etc, still pose significant and critical challenges when it comes to building apartments or individual houses. Because of the fragmented nature of manufacturing in the 2D Precast panels, the installation of services like plumbing, electrical wiring, air-conditioning etc. pose additional constraints and are not able to shrink the timelines of construction.
Grinding the misalignments between panels as well as treating the numerous joints between the columns, wall panels, slab panels and beams is also tedious and demands skilled workforce, expensive material like grouts and PU sealants, but still remain vulnerable to leakages and seepages since these are not made as monolithic.
3D Monolithic Modular Volumetric Precast
3D Modular Volumetric Precast (Onsite / Offsite) construction is an alternative to this current construction status-quo by promising transformative improvements in Time, Cost, Quality, Health and Safety. And most importantly, it offers predictability.
The 3D Monolithic Volumetric Precast eliminates the problems inherent in 2D Panel-based construction, and employs the least possible number of qualified engineers and trained technicians without leaving the construction to unskilled labour.
3D Monolithic Volumetric construction (also known as modular construction) involves production of three-dimensional modular units in controlled factory conditions prior to transportation to site. Modules can be brought to site either as a basic structure or with all internal and external finishes and services installed, and ready for assembly.
This unique method of construction offers the inherent benefits of concrete such as thermal mass, sound and fire resistance, as well as factory quality and accuracy, together with speed of erection on-site.
The 3D Volumetric Construction offers schedule benefits as most of the activities are undertaken away from the building site with minimal work at the building site. This enables taking some activities off the critical path and bringing certainty in the delivery of the project.
Key Advantages of Modular Construction
- Achieves superior quality through factory-based quality control
- Standardized design details for modular buildings simplify and reduce need for continued design inputs
- Reduced site labour: erection and finishing teams that install and complete modular buildings involve less workers on site than conventional buildings or 2D Precast
- Improved site productivity
- Reduced wastage during manufacture and on-site installation
- Greater reliability and quality as it is a monolithic structure with no, or minimal vertical joints
- Greater certainty of completion on time and on budget
- Modular construction sites have proved to be significantly safer than conventional construction methods.
This technology is unlike the conventional and 2D Precast methods and is cast complete with window and door frames, electrical and plumbing conduits already inlaid. A brief write-up of the process is illustrated below:
- The modules casts five sides in a single pour, or a three- dimensional shape creating a pre-designed shaped room or multiple rooms.
- The moulds are customizable during the modules’ design process. All openings - doors and windows, access points—piping and conduit and insulation are designed into the mould.
- Building all the features into the mould’s design reduces project turnaround time and costs.
- The openings for Windows, doors are so precise that they can be ordered straight from the drawings.
- The first fix MEP is installed at the time of casting thus reducing the time and labour required for chasing the walls, fixing the conduits and plastering the walls.
- This method is replicated and the modules are fitted together—side-by-side or atop of each other. This allows the roof of the first module to become the floor of the second module as they are vertically stacked, similar to Lego blocks or bricks. This ability to fit the modules together reduces construction time.
India’s first 3DMVP Project
The application of the 3DMVP technology was developed and optimized to meet the demands of Indian Market. In addition, recruitment and training of the Engineers in 3DMVP, its transportation and installation was undertaken. Armed with the above and with the personal presence and guidance of the technology owner from Australia, construction of a Pilot Building for Tata Housing was undertaken with 3DMVP.
A five-storey building with 20 apartments was manufactured and installed in 33 working days.
The images of the Casting, Transportation and Installation of the Tata’s Boisar Project is presented here: