Effect of different adding methods of Nano-TiO2 to micro-surfacing layer on NOx degradation.

This paper aimed to investigate the effect of Nano-TiO₂ as a semi-conductor additive on the pollutant's absorption of a micro-surfacing layer. In this research, micro-surfacing samples with Nano-TiO₂ values of 5, 7, 9, 11, and 13% (by weight of bitumen) and two types of aggregates (immersed and non-immersed aggregates in Nano-TiO₂) were tested to determine contaminant absorption and evaluate rutting performance at two temperatures of 20 and 40°C. The results revealed that NO_X absorption improved with increasing Nano-TiO₂, reaching 40% in samples with the optimal amount of Nano-TiO₂ (11% by weight of bitumen). Wheel track test results showed that the optimum sample had a better performance compared to the control sample. Also, it was observed that the absorption of pollutants decreased after conducting the wheel track test. [ABSTRACT FROM AUTHOR]