Reducing the effects of clogging and surface wear on the radiative properties of concrete blocks produced with recycled glass by incorporating titanium dioxide nanoparticles

This study aimed to demonstrate how incorporating titanium dioxide nanoparticles into concrete blocks made with recycled glass mitigates the effects of clogging and surface wear on pavement radiative properties. Using a reference concrete, four variants were formulated: with colourless, green, and amber glass, and a photocatalytic concrete with colourless glass. Three accelerated processes were applied to the concrete blocks in field: clogging, wear, and clogging on a worn surface. After each cycle of clogging and/or wear, solar reflectance and thermal emittance were measured to calculate the solar reflectance index (SRI). Surface clogging decreased the SRI for all concrete types, albeit less for photocatalytic concrete with colourless glass. SRI decreased with wear until a mean texture depth (MTD) near 0.80 mm, where a stabilisation trend was noted across all concretes. Photocatalytic concrete with colourless glass consistently showed the highest SRI values relative to the MTD. Clogging on worn surfaces indicated superior radiative properties for photocatalytic concrete with colourless glass at surface contamination degree (SCD) values less than 40%. In conclusion, conventional concretes with glass had inferior radiative properties compared to reference concrete. However, photocatalytic concrete with colourless glass showed superior radiative properties, indicating that nano-TiO2 addition reduced clogging and wear effects.