A comprehensive review of hydrophobic concrete: surface and bulk modifications for enhancing corrosion resistance

Abstract

Corrosion in concrete structures constitutes significant challenges, threatening integrity and requiring high maintenance costs. Hydrophobic concrete presents an emerging solution for addressing corrosion in concrete structures, especially in marine environments. This review article investigates advanced techniques for surface and bulk modifications of hydrophobic concrete, focusing on their efficacy in enhancing corrosion resistance. Surface modifications using silane-siloxane coatings and polyurethane treatments significantly reduce water absorption by up to 30% and chloride ion permeability by up to 50%. Bulk modifications incorporating nano-silica and calcium stearate demonstrate marked improvements in mechanical properties and corrosion resistance, with calcium stearate reducing corrosion rates by 40%. These treatments also contribute to an average increase in compressive strength of 15% and a decrease in corrosion current densities, indicating practical utility in environments such as marine conditions. Additionally, innovative techniques like fluorosilane treatments and steel fibres further fortify impermeability and structural integrity, demonstrating the versatility of hydrophobic concrete in addressing corrosion challenges. Moreover, using eco-friendly ingredients underscores its potential for sustainable infrastructure development. In summary, hydrophobic concrete offers a comprehensive strategy for combating corrosion, providing surface and bulk modifications that enhance durability, reduce maintenance costs, and ensure the long-term sustainability of modern infrastructure.