温拌胶粉改性沥青低温性能及其与集料黏附性分析

通过弯曲梁流变(BBR)试验、接触角测量及原子力显微镜(AFM)测试等方法,从宏观和微观角度对老化前后温拌胶粉改性沥青(WCR)低温抗裂性及其与集料黏附性的变化规律进行研究,并以热拌胶粉改性沥青(HCR)作为对比。结果表明:随着老化程度的加深,HCR、WCR的蠕变速率(m)和弯曲蠕变劲度(S)的比值(m/S)减小,低温抗裂性能变差,WCR的低温抗裂、抗老化性能均优于HCR;老化前后HCR、WCR与三种集料的黏附性能大小依次为石灰岩＞玄武岩＞花岗岩,WCR与集料的黏附性均优于HCR;老化前后两种沥青的微观Derjaguin-Muller-Toporov(DMT)模量与低温流变参数(m/S)呈良好线性关系,且基于Johnson-Kendall-Roberts(JKR)力学模型得到的微观表面能、黏附功分别与基于表面能理论得到的宏观表面能、黏附功呈较强相关性。

Analysis of Low Temperature Performance of Warm Mix Crumb Rubber Powder Modified Asphalt and Its Adhesion to Aggregate

Through bending beam rheological(BBR)test,contact angle measurement and atomic force microscope(AFM)test,the low temperature crack resistance of warm mix crumb rubber powder modified asphalt(WCR)before and after aging and its adhesion change law to aggregate were studied from macroscopic and microscopic perspectives,and hot mix crumb rubber powder modified asphalt(HCR)was used as a comparison.The results show that with the increase of aging degree,the ratio of creep rate(m)to bending creep stiffness(S)(m/S)of HCR and WCR decreases,and the low temperature crack resistance becomes worse.The low temperature crack resistance and aging resistance of WCR are better than HCR.The adhesion of HCR,WCR to three kinds of aggregates before and after aging is limestone>basalt>granite,and the adhesion of WCR to aggregates is better than that of HCR.The micro Derjaguin-Muller-Toporov(DMT)modulus of the two asphalts before and after aging has a good linear relationship with the low temperature rheological parameter(m/S),and the micro surface energy and adhesion work obtained based on Johnson-Kendall-Roberts(JKR)mechanical model has a strong correlation with the macro surface energy and adhesion work obtained based on the surface energy theory.