Influence of silane-based water repellent on the durability properties of recycled aggregate concrete

This paper aims to investigate the durability properties of recycled aggregate concrete treated with silane-based water repellent agents, since the high water absorption of recycled aggregate concrete is a major factor jeopardizing its durability. Different dosages of silane-based water repellent agents were either coated on the surface of the concrete (hereafter “surface silane treatment”) or integrally added into the concrete mixture (hereafter “integral silane treatment”). The mechanical and durability properties of the treated concrete were evaluated. It was found that integral silane treatment can improve the durability of recycled aggregate concrete, but may lead to reductions in compressive strength; surface silane treatment is more effective in improving the resistance of recycled aggregate concrete to capillary water absorption, carbonation and chloride penetration than integral silane treatment.