Rajeev Gupta
Rajeev Gupta, Business Head- Construction Systems BU, Chryso India
Concrete is one of the most commonly used building and construction materials. However, due to its composition, is often susceptible to damage and deterioration from water and chemical penetration. Concrete can be considered as a micro porous and permeable material. Porosity refers to the amount of voids left in concrete, is expressed as a percentage of the total volume of a material. Permeability expresses that how well the voids are connected.

Therefore, these qualities results pathways to form that allow the ingress and movement of water into, and through, along with the cracking that occurs due to shrinkage. Thus, these voids, pores and capillaries become the major sources for water leakages from the concrete structures.

Crystalline Waterproofing Technology

Although crystalline waterproofing technology has been around for more than 3 decades, it is still considered "state-of-the-art" and has only recently been embraced by the construction industry as a superior replacement for conventional membranes. Crystalline waterproofing systems rely on a technology that turns porous concrete in to an impermeable barrier. The result is a structure with reduced cracking, self-sealing and waterproofing abilities which provides a powerful defense against water damage and corrosion of reinforcing steel.

Unlike sheet membranes, which rely on an additional hurdle to shield the concrete from moisture, crystalline waterproofing system actually transforms the concrete into a water-resistant barrier. It becomes an integral part of the concrete matrix when applied to existing concrete or added to the mix at time of batching.

The crystalline waterproofing chemistry can be introduced into new concrete as an admixture, a dry-shake product, or a surface-applied coating. For older (i.e., cured) concrete, surface-applied coatings are used. The substrate must be wet for the chemicals to move through the concrete and for the chemical reaction to occur. With a surface coating application, the high concentration of chemicals at the surface naturally tends to spread out or diffuse into the water saturated substrate. Keeping the concrete moist maintains a conduit for the crystalline chemicals to travel.

Recently built structures and heritage buildings need water protection too! Whether we are waterproofing a new structure or repairing leaks, concrete waterproofing treatments allow us to turn existing concrete into a waterproof barrier reliably and cost-effectively

NBM&CW April 2014