Experimental Investigation on the Performance of SBS-Modified Asphalt Waterproofing Membrane by Thermo-Oxidative Aging and Freeze–Thaw Cycle

With global warming in recent years, extreme weather conditions have increased in frequency and intensity, exacerbating the challenges for waterproofing materials. The current stages of SBS asphalt waterproofing membrane aging research mainly focus on the raw materials and modifiers in a single factor; multifactor-coupled aging research is less studied. This study focused on the coupled aging characteristics of SBS-modified asphalt waterproofing membranes, aiming to reveal the mechanism of its influence on the material’s performance under the environmental effects of high temperature and freeze–thaw. Through the accelerated aging test, we simulated the environmental conditions of high temperature in summer and freeze–thaw in winter to observe the mechanical properties of waterproofing membranes, low-temperature flexibility, and apparent phenomena. Then, Fourier transform infrared spectroscopy (FTIR) evaluated the performance and chemical structure of SBS-modified asphalt waterproofing membranes after aging by the coupled aging of the thermo-oxidative freeze–thaw cycle. The results showed that the low-temperature flexibility of the waterproofing membranes was significantly reduced after the coupled aging effect, and, at the same time, their tensile strength was also reduced. However, despite the tensile properties being impaired, the membrane maintained good ductility, and its elongation at break did not fall below 47%.