Effects of Incorporating Acrylic Particles on Mechanical and Photocatalytic Properties of Recycled Concrete

To mitigate the impact of vehicular emissions on air quality and reduce the concentrations of atmospheric pollutants, this study developed pavement materials with purification functions using TiO2 as a photocatalyst and construction waste as an aggregate. Polymethyl methacrylate (PMMA) acrylic particles were added to enhance the light transmittance of the concrete, and the volume replacement percentages of PMMA replacing aggregate (sand) were 20%, 40%, 60%, and 80%. The physical, mechanical, and photocatalytic properties of the photocatalytic recycled concrete were characterized through testing the water absorption, drying shrinkage, compressive strength, flexural strength, splitting tensile strength, and degradation efficiency. The results showed that the addition of PMMA increased the water absorption, reduced the drying shrinkage, and decreased the mechanical strength (compressive strength, flexural strength, and splitting tensile strength) of the photocatalytic recycled concrete. Notably, PMMA significantly improved the photocatalytic efficiency by increasing the light transmittance, but the promotion effect was weakened when the PMMA replacement percentages exceeded 60%. When the PMMA replacement percentages ranged from 20% to 40%, the photocatalytic recycled concrete maintained good mechanical strength and photocatalytic efficiency. This study presents an effective approach for improving the catalytic efficiency of photocatalytic recycled concrete while concurrently enhancing the utilization rate of construction waste.