The use of construction chemicals - the right way
Construction chemicals and waterproofing is coming of age. There are plenty of new products available. Using them the right way is the key
Building construction requires strengthening. Construction chemicals have always been playing important roles in virtually all sorts of construction projects, be it industrial projects, residential building projects, commercial building projects and so on. These chemicals are often used in various elements of projects in order to achieve various important qualities such as workability, durability etc. Construction chemicals exist in many varieties from large number of manufacturers worldwide.
Construction chemicals are used by the construction and civil repair industry. These chemicals help enhance concrete strength and quality, provide water-tightness and protect concrete structures from atmospheric degradation. Several manufacturers offer a wide range of products for applications in concrete modification, waterproofing, repair and rehabilitation of structures. Products like admixtures for concrete, sealants, grouts, concrete curing compounds, tile fixing adhesives, waterproofing chemicals, membranes, jointing compounds, crack repair and special application mortars are offered.
Construction chemicals and waterproofing are also widely used for infrastructure projects such as bridges and flyovers, roads and highways construction, airport buildings, overhead bridges, among others.
The surging demand for waterproofing membranes during the forecast period (2019-2029) will be driven by governmental focus worldwide, especially in developing countries, on water conservation and wastewater treatment infrastructure; repair and renovation of existing infrastructure in developed countries; waterproofing of roofs, walls, tunnels and landfills; and use in mining tunnels around the world, thanks to the performance and adaptability of waterproofing membranes in extreme environments.
Pranav Desai, head, CDIC & product development, Nuvoco Vistas Corp, says, “The diversity of construction chemicals and advanced materials (CAMs) has expanded by leaps and bounds. Today, it not only includes concrete admixtures but also adhesives and sealants, coatings, insulation materials, and polymer composites. These CAMs—gifts of the petrochemical revolution—are designed to extend the otherwise “natural” life of the structure, give integrity, provide protection, and cut down material waste.”
He goes on say that concrete admixtures, for instance, which are increasingly used for producing super-strong concrete, comprise plasticisers/super plasticisers, accelerators, air-entraining agents, bonding agents, retarders, shrinkage reducers, and so on. While adhesives and sealants help in joining dissimilar building components in a flexible, cost-effective, and durable manner, coatings enable lasting protection against weather and corrosion. Insulation materials like polymer foams help not only in thermal, acoustic, fire, and impact insulation but also enable light weighting of building structures and components.
Polymer composites come in many different forms, and given their high strength-to stiffness ratio and low density, they offer durability, low weight, impact resistance, design flexibility, parts consolidation, toughness, and heat resistance. Waterproofing starts from the building’s basement, podium, bathrooms and exterior walls to top of the terraces. In fact, terraces, roof top decks and balconies are an integral part of waterproofing and require special treatment since they are exposed to extreme weather like sun and rain and footfalls.
Last year, JK Cement launched JK Cement ShieldMaxX, a white cement based universal waterproof putty, across UP, Bihar, MP, Jharkhand, Chhattisgarh and West Bengal. Developed using advanced German technology JK Cement ShieldMaxX protects walls from dampness, and efflorescence, resulting in longer paint life. This innovative product, contains Active SiH4 Molecules and is suitable for application on both interiors and exteriors/walls, making it a uniquely differentiated product proposition. It is perfectly suitable for bricks, solid or hollow blocks, AAC Blocks, concrete surface, plaster board on RCC/MIVAN/POP or similar surfaces. Niranjan Mishra, business head (white cement), Jk Cement, says, “Being customer centric and a pioneer in the white cement industry, we have always striven to launch quality innovative products to cater to the ever changing and growing needs of the consumers.
The launch of JK Cement ShieldMaxX is aimed at addressing the current market demand and the consumers need for a versatile product with excellent waterproofing property for beautiful interiors and exteriors. We see great potential in JK Cement ShieldMaxX and really look forward to deliver a quality product.”
Waterproofing membranes are utilised across the board in a variety of infrastructure projects, with roofing applications accounting for a market share of more than 30% while walls and building structures collectively account for more than half of the total market share on the back of renovation and upgradation of existing water management systems.
The modern ways of waterproofing are liquid brush applied solutions which can be bitumen-based, acrylic-based, PU-based, etc, and pre-formed membranes which are loosely laid or torched or self-adhesive membranes. The liquid membranes (bitumen, resin, acrylic, polyurethane, water or solvent-based, in one or two-components) can be used in civil and industrial projects.
In recent years expensive remedial work to correct failures in below-grade waterproofing systems has motivated owners and designers to seek high-performance and reliable waterproofing solutions to prevent water ingress. Waterproofing chemicals are classified into 2 segments like hydrocarbon and polymers. Hydrocarbon is an organic sticky, viscous and waterproof compound that is employed as waterproofing material for roofs.
Sanjay Bahadur, CEO, construction chemicals, Pidilite Industries, says, “More and more liquid waterproofing coatings like polyurethane and poly-urea hybrids are gaining acceptance in the market and one expects this trend to continue with new advances in industrial chemistry. Compared to pre-formed membranes, liquid applied membranes based on polyurethane/polyrea technology that is more suited to Indian conditions as these membranes provide seamless or jointless systems which make them more application-friendly. Another trend now is more customers are seeking solutions that provide insulation along with waterproofing. Again here, polyurethane-based technologies help to achieve this dual end. Polyurethane dense foams are used for roof insulation purpose followed by special coatings of liquid PU under Dr. Fixit Low Energy Consumption (LEC) system and Dr. Fixit Blueseal brand names.”
New generation water proofing solution - a water-based cross-linked polymer sealant, when mixed with crusher-dust, provides a 100% water-proof seal to any porous road surface. It is applied with a slurry truck over the road surface. The admixture penetrates the voids and cracks in the BDM, BC, BM, SDBC or premix carpet and hardens within a couple of hours to provide a durable, 100% water-proof seal, says Desai.
Waterproofing wet areas has always been a challenging task for the construction industry. With the introduction of the drywall concept, the construction industry is undergoing a change of materials being used to construct these wet areas. This has also created a need for reliable waterproofing systems. Current practices of waterproofing systems were originally designed for conventional brick/block masonry walls.
With the changing skyline, buildings are becoming more beautiful and making use of smarter materials. In such buildings, bathrooms are not just an area to clean up, but are viewed as personal spaces to get refreshed and rejuvenated. This calls for use of different building materials. Drywall panels are one such component, which are gradually becoming the material of choice in the construction of bathroom walls. Use of drywall panels is advantageous to developers, but it is important to ensure the water tightness of these areas and still accommodate movement that would occur in these panels.
Single component, waterproof and flexible coating can be the perfect solution for under ceramic coverings in showers and bathrooms. Unlike traditional cementitious waterproofing systems, not only has higher elongation properties (to accommodate movement at joints), but also allows the tiles to be laid directly over it. Coupled with special waterproofing tapes for the joints and gaskets for the pipe penetrations and drain cut outs, the bathroom can be made completely water tight. The solution saves time and cost for an overlay for protection before the tiling activity commences, says Desai.
The driving principle is to minimise water penetration through the concrete matrix. This is basically achieved in two ways - first, through minimizing mixing water demand using plasticizing chemicals, hence leaving lesser voids and ensuring higher density, and secondly by closing / blocking / refining / filling the voids / pores through formation of organic crystals, in sync with the cement hydration process.