Hongwei Du

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%.

Polyester-based, self-adhesive asphalt waterproofing membranes have garnered significant attention due to their extensive use in building-waterproofing projects, with their resistance to aging in complex environments being particularly crucial. This study evaluates the performance changes of these membranes under thermo-oxidative aging and freeze–thaw cycling conditions. The thermo-oxidative aging process was simulated using a thin-film oven and combined with freeze–thaw cycle tests to assess membrane performance at various aging stages. Changes in functional groups were analyzed via Fourier Transform Infrared Spectroscopy (FTIR), and tests for low-temperature flexibility, tensile properties, and peel strength were conducted. The results demonstrated that aging significantly reduced the membrane’s low-temperature flexibility and peel strength, accompanied by oxidative reactions and a loss of lightweight components. This study provides essential data on the aging behavior of the membrane and offers a theoretical foundation for its long-term application in practical engineering.