Low-pollution asphalt: Road performance, emission reduction efficacy, and modification mechanism

Abstract

To further improve the emission reduction efficiency and enhance the road performance of emission reduction modified asphalt. A low-pollution asphalt (TBD-A) was prepared with tourmaline, biochar, and diatomite (TBD). A testing and evaluation method for the emission reduction efficacy of TBD-A has been proposed. The road performance of TBD-A was evaluated based on DSR, MSCR, BBR, and LAS. The evolution law of the emission reduction effect of TBD-A was clarified. Based on DSC, FTIR, and TG, the improvement mechanism of the road performance and emission reduction mechanism of TBD-A were revealed. The results show that the high-temperature performance, creep recovery ability, and fatigue life of TBD-A increase with TBD content rising. The low-temperature performance of TBD-A is superior to that of asphalt slurry. Controlling the TBD content and temperature can ensure the excellent low-temperature performance of TBD-A. The emission reduction efficacy of TBD-A increases as temperature and adsorption time rise. The comprehensive emission reduction rate of TBD-rubber-powder asphalt is the highest, reaching 64% at 190 °C. TBD and asphalt are physically blended. TBD increases asphalt's glass transition temperature while decreasing the thermal decomposition rate. The temperature stability and sensitivity of asphalt have been improved. Asphalt harmful substances are adsorbed by the multi-level pore structure of TBD, as well as are reduced and degraded by the spontaneous polarization effect.