沥青老化效应的试验研究

Tests of the Asphalt Aging Effect

为了研究沥青老化对路面使用性能影响,通过旋转薄膜烘箱对沥青进行短期老化,再用压力老化仪对老化的沥青进行不同时间的老化,然后对不同程度的老化沥青进行针入度、软化点、延度、不同温度下的粘度、蠕变劲度和蠕变变化速率、动态粘弹性参数的试验。随PAV老化时间的增加,老化沥青的针入度逐渐减小,针入度指数PIPEN逐渐增大,软化点逐渐提高,延度越来越小,而粘度相反变化,复数剪切模量G*、蠕变劲度逐渐增大,相位角δ、蠕变速率则逐渐减小,指数函数更能表征老化对其粘温关系的影响。结果表明老化使沥青弹性增强,感温性减弱,耐久性降低,抗疲劳开裂能力变差,缩短了路面使用寿命。

In order to research the service performance impaction of aging asphalt on asphalt pavement, short-term aging by using RTFOT （Rolling Thin Film Oven Test） and various hours aging by using PAV （Pressure Aging Vessel） is conducted, and performance indexes are tested on the different PAV aging time asphalt, including penetration, softening point, ductility, viscosity in different temperature,creep stiffness and creep stiffness change rate, and dynamic viscoelasticity parameter.With the PAV aging time of the asphalt increasing, penetration reduced, penetration index and softening point increased, ductility grew and viscosity changed contrary, complex shear modulus G^＋ and creep stiffness increased, phase angle δ and creep rate reduced gradually.The exponential function explained better characterization of the aging asphalt viscosity-temperature relationship.The results show that aging asphalt enhances flexibility, decreases temperature., durability, anti-fatigue cracking ability, and the pavement life.