New age additives from Pidilite
Waterproofing and thermal insulation are two chronic problems plaguing the construction community. This is not to say that the builders do not understand the importance of these aspects. Most often they simply do not have the necessary skill sets to implement these solutions effectively. Pidilite realised this and has come up with a range of solutions in waterproofing and thermal insulation that can help. It has gone beyond products and introduced systems to deal with the challenges on the ground.
Pidilite: a common household name
Pidilite, which started in 1959 manufacturing only white glue Fevicol, has now grown into a huge product portfolio, catering to various categories including paint chemicals, automotive chemicals, art materials and stationery, fabric care, maintenance chemicals, industrial adhesives, industrial and textile resins and organic pigments preparations. Most of these products were developed through the company´s own strong in-house R&D. Today it has 6000 distributors with products sold in more than 80 countries and has more than 4000 employees. Pidilite has set up a state-of-the-art research centre in Singapore, which has a strong focus on construction chemicals. This innovation centre is now a member of Singapore Chemical Industry Council (SCIC). The company also has an R&D arm at the Dr Fixit Institute at Mumbai, in India, and has set up a Dr Fixit Knowledge Centre at Kochi to train construction personnel in proper application of waterproofing solutions.
Some of the biggest brands in adhesives and sealants category, like Fevicol, M-seal and Fevikwik, come from Pidilite. Other major brands include Cyclo and Motomax for auto care, Ranipal for fabric care, Fevistik glue stick for hobby and craft projects and Dr Fixit, Pagel and Roff for construction industry. Under the Dr Fixit brand, Pidilite offers a range of waterproofing and repair solutions.
The construction chemical products from Pidilite are available in over 30 countries including in the Middle East, Thailand, Singapore and Brazil.
Dr Fixit Pidiproof LW+
Pidilite´s largest selling brand in the construction chemicals category is LW+. It is an integral liquid waterproofing compound that reduces water-permeability of concrete. Waterproofing is a process that is designed to prevent water from penetrating the structure. Typically it is done in various layers and stages to create multiple barriers so that water does not seep in the structure. These layers form the ´Building Envelope´ that waterproofs the structure.
Excessive reliance on conventional and outdated systems, and lack of trained expertise in using modern products, are some of the reasons that lead to poor water-proofing. More than 85 per cent of the concrete produced in India is still made by volume batching. There is hardly any control on the water to cement ratio at these sites. The control on the quality of sand and aggregate is very limited. The concrete usually has high water permeability. As a result, salts and water seep in the concrete at the foundation of the building. Salts and water not only deteriorate the concrete, but they also rise up in the walls through capillary channels present in mortar and bricks. This leads to persistent dampness in walls and leads to peeling and cracking of paint on the wall. Pollutants like CO2 dissolved in water can cause rebar corrosion and weaken the structure.
If the mortar is site-mixed, as it is in most cases in India, it lacks adhesion and cohesive properties and gives rise to cracks in mortar and plastered surfaces.
Cracks and moisture bring down the actual life of the structure from its designed level. This could be avoided by using Dr Fixit Pidiproof LW+. LW+ modifies the properties of cement to make it waterproof and consequently prevents rusting of steel bars completely. It has surface-active plasticising agents, polymers and additives that prevent aggregate segregation.
Science behind LW+
When cement hydrates, narrow channels called capillaries are formed in the structure. These voids become a route for ingress of chlorides, sulphates, carbon dioxide, etc. LW+ breaks these capillaries. Hydrophobic (water repelling) polymeric molecules present in LW+, fill these pores and increase the water impermeability of the mortar or concrete.
The polymers in LW+ have the same charge as the cement particles. As a result, cement particles disperse well and release the locked water. This improves workability, hydration and increases compressive strength of concrete/mortar. As the micro-fine particles in LW+ penetrate deeper in the interstitial spaces it reduces the rebound loss in trowelling and consequently improves mason productivity.
Comparison of normal concrete with Dr Fixit Pidiproof LW+ concrete For the same set of cement, sand, aggregates and water, the effect of adding Dr Fixit Pidiproof LW+ into the concrete has been compared and shown below.
The compressive strength of concrete specimen with Dr Fixit Pidiproof LW+ shows an increase of 7 per cent in 28 days. The RCPT value (measure of chloride penetration), water permeability and drying shrinkage of the concrete specimen with LW+ shows 27 per cent, 39 per cent and 30 per cent reduction, which is quite significant. What is remarkable here is that Dr Fixit Pidiproof LW+ concrete has shown improved impermeability over PPC concrete, which by itself is more impermeable than the OPC concrete. No other liquid integral waterproofing compound or admixture in the market offers all the features for concrete/mortar improvement like Dr Fixit Pidiproof LW+ does. The normal admixtures do not reduce water permeability, significantly, hence no secondary waterproofing is imparted to the structure.