Strength enhancement of recycled aggregate pervious concrete using a cement paste redistribution method

The applications of pervious concrete made with recycled aggregate (RA) have been hindered by its significantly reduced strength. In this study, a silane polymer emulsion treatment method was used to promote the strength of pervious concrete while maintaining its permeability. The mechanical and physical properties of RA pervious concrete were experimentally investigated. Membrane-forming ability tests and X-ray micro-tomography were conducted to determine the influence of the silane polymer emulsion on the membrane-forming behaviour and thickness distribution of cement paste. The results revealed that silane treatment significantly improved the strength of RA pervious concrete while maintaining acceptable permeability due to the redistribution of the cement paste. Meso-structure analyses confirmed that more cement pastes gathered around the bonding regions between adjacent RA particles. The findings suggest that this method can be used to enhance the strength of RA pervious concrete through effective utilisation of cement paste. [Display omitted] •Silane polymer emulsion treatment was used to enhance strength of RA pervious concrete.•Strength of RA pervious concrete is obviously enhanced with maintaining desired permeability.•Meso-structural features were obtained with X-ray tomography and lineal analysis method.•Strength enhancement originates from more cement paste gathering around the bonding regions.