高原地区多因素耦合作用下橡胶沥青性能评价

Evaluation on the Performance of Rubber Asphalt Exposed to Multi-factor Coupling in Plateau Area

为提高沥青路面在高原地区多因素耦合作用下的服役寿命,以橡胶沥青为主要试验原料,将实地采集的青海格尔木地区气象数据应用于自主研发的可程式恒温恒湿阳光试验机中模拟高原地区多因素耦合作用下沥青结合料劣化过程。以针入度、软化点、延度、弹性恢复、布氏黏度(180℃)、抗剪强度(25℃)和弯曲梁流变特性(BBR)等指标研究沥青性能随多因素耦合作用龄期的变化规律;在此基础上,借助荧光显微镜(FM)、扫描电镜(SEM)和傅里叶红外光谱(FTIR)等手段,进一步探究高原地区多因素耦合作用下橡胶沥青性能演化机理。研究结果表明:高原地区多因素耦合作用持续劣化沥青胶结料性能;与基质沥青相比,橡胶沥青在高寒地区的适用性及使用效果具有明显优越性;TOR改性橡胶沥青(TAR)低温蠕变速率与劲度模量比值(m/S)高至基质沥青3. 7倍与橡胶沥青1. 2倍,均匀分散的TOR连接剂形成的交联结构更利于提高橡胶沥青的稳定性及耐久性。

In order to improve the service life of asphalt pavement under multi-factor coupling in the plateau area,rubber asphalt was used as the main experimental material,and the meteorological data collected in the field of Qinghai Golmud was applied to the self-developed programmable constant temperature and humidity test machine in the simulated plateau area degradation process of asphalt binder under multi-factor coupling.The penetration,softening point,ductility,elastic recovery,brinell viscosity(180℃),shear strength(25℃)and bending beam rheological properties(BBR)were used to study the variation of asphalt performance with multi-factor coupling age.On this basis,the fluorescence microscope(FM),scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)were used to further explore the mechanism of rubber asphalt performance evolution under multi-factor coupling in the plateau.The results show that the multi-factor coupling effect in the plateau region continues to degrade the performance of asphalt binder;compared with the matrix asphalt,the applicability and use effect of rubber asphalt in alpine regions is obvious;the low temperature creep rate and stiffness modulus ratio(m/S)of TOR modified rubber asphalt(TAR)is 3.7 times higher than matrix asphalt and 1.2 times higher than rubber asphalt.The cross linked structure formed by the uniformly dispersed TOR linker is more advantageous for improving the stability and durability of the rubber asphalt.