Changing face of technology in construction materials
There is marked uncertainty, change and complexity in operations, and businesses have now shaken up their industries. By introducing innovative products and services and streamlining systems, businesses are braving the creative storm and are pacing themselves for the future. At the core of this disruption is technology, which has accelerated growth across sectors and prompted the use of innovation in business. In the real estate and construction space, technology and innovation are often seen as responsible for shaping the cities we live and work in and are at the forefront of this disruption. At present, most construction materials we use are non-renewable and with the pace of development, we are on the brink of facing a serious scarcity of resources; signs of which are evident. Some prime examples of depleting resources are sand, timber and other raw materials required for cement.
At this juncture, technologists, engineers and regulatory bodies have to come forward with innovative and 'safe and sufficient' technologies. To combat the shortage of coarse and fine aggregates, the technology of sintering fly ash has already been developed and is in place. Within the industry, there is a growing need to consciously use this in lower grades of concretes, which can liberate the natural aggregates for higher grades of concretes. At this stage, the role of regulatory bodies like National Council for Cement and Building Materials (NCCBM), Bureau of Indian Standards(BIS) and National Building Code (NBC) is integral to standardisation of this development for widespread manufacturing and use.
A big opportunity for the construction sector to make optimum use of, is recycling building debris, just by simple controlled crushing and subsequent screening to different fractions. By promoting this concept among smaller real estate developers at local consumption point levels, this small ripple can create big waves. Not only will it help the local administration to keep the towns and cities free of debris, it will also minimise long distance hauls for delivering transport and saving fossil fuel and the associated pollution and risks of road accidents, traffic congestion, etc. Although this supporting technology is very basic and simple, its implementation requires honest and sensible facilitation from the local civic bodies.
As far as the 'safe and sufficient' technologies are concerned, there is a huge scope for development. The basic premise of which, is playing with the design aspects, for example, keeping the capacity same, engineers can improvise in shape and configuration of a RCC column and bring in economic material consumption by leveraging section modili properties.
Another breakthrough in the construction world is the use of ferro-cement, which is a material comprising wire meshes and cement mortar. Besides bringing in considerable savings in material consumption safety by judiciously using it in building components, its applicability is vast due to low weight and non-requirement of a framework.
With the right use of ferro-cement, it also offers pleasing aesthetics. But before we can apply this widely in the industry, this improvised but scientific technology needs to be validated and vetted by BIS, NCCBM for better assurance and large s cale acceptance. Precast technology with ferro-cement improvisation will also open a new horizon in rural housing with the following distinct advantages:
1.Safe and strong components.
3.Flexible adoption - when using ferro-cement, people can opt for a strong and stable frame only, while elements such as walls, roof and partitions may be completed with locally available materials like bamboo, timber, stone lamina, etc.
4.Sleeker structures with highest properties, prevention of wastage of materials.
As an example of the use of ferro-cement in roofing systems, precast roofing slabs of 1000 mm x 500 mm size are 50 mm thick, cast with 1:4 sand-cement, latex modified mortar, 4 x 5 mm bars at the periphery and two at the centre along the shorter span and chicken wire mesh at the mid depth, weighing around 67 kg, when fully dried. During load trial over a period of one month each slab of 0.5 m2 area withstood around 470 kg of live load, apart from its self load. Such innovative designs can not only save coarse aggregates and steel to a great extent, but also provide higher load carrying capacity safely. This configuration was a breakthrough for the construction industry.
The scope and opportunity of playing around with the shapes and configurations are unlimited and can be economised in mass and centralised constructions.
High performance concrete has also been an important innovation in the construction sector as complex building and infrastructure projects can greatly benefit from this. Due to this, we are able to delve deeper into the complexities of cement, binder, aggregates, water, admixture and other materials to develop a base that is customised to the nature and requirements of the structure. At present, we are pumping C95/M120 Self Compacting Concrete with minimal creeping and shrinkage to the 118th floor of a premium property in Lower Parel (Mumbai), as well as production of M50 high early strength concrete for tunnel segments of the upcoming Mumbai Metro with a corrosion free life of up to 150 years.
For many years, architects and structural engineers have demanded the best construction materials, which has led to out-of-the-box thinking and development of complex design tools. As a result, self compacting, leveling and placing concrete was created, which gives engineers and architects the confidence to design their dream projects with ease.
By bringing in cutting-edge innovation in material chemistry and rheology studies to the local and small volume needs, the first ready to use wet mix concrete was created in small 35 kg bags. This unique product guarantees quality assurance and sustainable construction in the space of affordable housing, job sites in conjusted areas where accessibility is a big challenge and also big construction sites where low volumes of concrete are required for ease of construction. The product is also a prime example of disruptive innovation in the repair segment, which has been dominated by dry mix products.
Three-dimensional printing, a technology which has been making waves in several other industries, has also found its way into building segment and is highly acclaimed as the future of construction. Some of its key benefits are speed, design freedom, flexibility, accuracy and we are already working with students and professionals to develop high speed 3D printable materials like mud, mortar and concrete.
Another interesting development in the construction segment, has been the evolution of fibres. Since Biblical times, fibres have been used to strengthen brittle matrices, but it was only during the 1960s, that steel fibres were proposed as a dispersed reinforcement for concrete. Since then, the material has developed considerably, so has our knowledge of the material, based on theoretical solutions and experimental findings. We have seen that test methods, which have been transferred from high-strength composites are very effective, however, due to compatibility issues, practical applications are few. To address this, microfiber pre-blended cement has been made available in the Indian markets, which acts as a binding agent and ensures strong and durable structures.
During the process of construction, plastering is one of the main and most challenging activities due to several reasons including shortage of skilled manpower and plastering sand in metros. To solve this problem, wet spray plastering systems have been innovated. This is essentially, a very high-quality plaster with low water absorption and permeability along with a high bond strength against the host surface. By using this in construction, builders are able to enjoy high productivity, maintain consistency, reduce their dependency on labour and ensure negligible wastage of raw materials.
With these and several other innovations, it is now the responsibility of all stakeholders to wake up, think and contribute to such simple yet effective technologies for the service to mankind. In developed countries, there is a fine for wasting food, similarly 'energy saved is energy produced' and we must move, with conscious efforts toward the new proverb 'materials saved are materials preserved, and sustainability achieved'.
Authored by Pranav Desai, Head, Construction Development and Innovation Center (CDIC) and Product Development, Nuvoco Vistas Corp Ltd.