Experimental Investigation on Hydrophobic Treatment of Cement Concrete with Organosilane Based Compound

Abstract

Concrete is the most widely used construction material owing to its good strength, mouldability and robustness. However, its durability has always been a cause of concern arising mainly due to the fact that concrete is highly porous, microcracked and hydrophilic in nature making water ingress into it unavoidable. Water ingress is the primary cause for all major durability related issues in concrete such as freezing and thawing, reinforcement corrosion, carbonation, efflorescence etc. It is thus evident that to prevent deterioration and thereby increase durability and service life of concrete structures, water ingress into it must be minimized. This can be accomplished by a number of methods out of which hydrophobic treatment of concrete is nowadays becoming popular. Surface Hydrophobic Treatment and Integral/Bulk Hydrophobic Treatment are two main ways to induce water repellency in concrete. In this work, the efficacy of integrally incorporating a silane product into concrete and providing a surface treatment using the same product on the mechanical, durability and physical properties has been studied. Integral modification did not yield satisfactory results in case of water proofing the composites with the Water Contact Angle values lying below 90˚ in the hydrophilic range. Whereas, the surface treatment reported a successful hydrophobic modification reporting Water Contact Angle value as high as 157.1˚. The Water Contact Angle values for all surface modified samples were over 150˚ which lies in the superhydrophobic category along with the composites exhibiting a self-cleaning behaviour with very little effect on the compressive and tensile strength.