高粘度改性沥青结合料(HVMA)可以提高沥青混合料的粘结性,被广泛用作多孔沥青路面的聚合物改性结合料。然而,由于混合物中的高空隙率,HVMA易受温度老化的影响,氧气,水,阳光,和其他气候条件,这降低了路面的性能。在高温和多雨地区,湿热环境的影响会对沥青结合料的性能产生不利影响。因此,研究HVMA在湿热环境影响下的老化特性,以促进其作为高粘度改性剂的应用。设计了湿热循环老化试验(HCAT),以模拟在高温地区降雨后将雨水保留在路面内时HVMA的老化。一种基础沥青和三种HVMA(简称SBS,A,B,分别)在本研究中被选中。短期老化试验,湿热循环老化试验,并对基础沥青和三种改性沥青结合料进行了长期老化试验。傅里叶变换红外光谱(FTIR),热重分析(TGA),和动态剪切流变(DSR)测试用于在微观和宏观尺度上评估粘合剂的性能。通过比较四种粘合剂老化前后的折射率变化,研究了湿热环境对HVMA性能的影响。发现与TFOT和PAV测试相比,湿热环境的影响加速了聚合物的分解和羰基的形成,TGA进一步证实了这一点。此外,HCAT后样品的热稳定性得到改善。此外,复数模量的主曲线表明,湿热循环使沥青结合料的高温抗车辙能力显着提高。以上所有结果都证明了湿热循环的作用可以加速HVMA的老化并缩短其使用寿命。
High-viscosity modified asphalt binder (HVMA) is used widely as a polymer-modified binder in porous asphalt pavement because it can improve the cohesiveness of the asphalt mixture. However, because of the high voidage in the mixture, HVMA is vulnerable to aging induced by temperature, oxygen, water, sunlight, and other climatic conditions, which degrades the performance of pavement. The properties of asphalt binder are affected adversely by the effects of hygrothermal environments in megathermal and rainy areas. Therefore, it is essential to study the aging characteristics of HVMA under the influence of hygrothermal environments to promote its application as a high-viscosity modifier. A hygrothermal cycle aging test (HCAT) was designed to simulate the aging of HVMA when rainwater was kept inside of the pavement after rainfall in megathermal areas. One kind of base bitumen and three kinds of HVMA (referred to as SBS, A, and B, respectively) were selected in this study. Short-term aging tests, hygrothermal cycling aging tests, and long-term aging tests were performed on the base bitumen and three kinds of modified asphalt binder. Fourier-transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), and dynamic shear rheological (DSR) tests were used to evaluate the properties of the binders on the micro and macro scales. By comparing the index variations of the four binders before and after aging, the effects of the hygrothermal environment on the properties of HVMA were studied. It was found that the effects of the hygrothermal environment expedited the decomposition of the polymer and the formation of carbonyl groups compared with the TFOT and PAV test, which TGA confirmed further. Moreover, the thermal stability of the samples was improved after HCAT. In addition, the master curves of the complex modulus showed that hygrothermal cycles made the high-temperature rutting resistance of asphalt binder increase significantly. All of the results above verified that the effect of hygrothermal cycling could accelerate the aging of HVMA and shorten its service life.