热、光、水耦合老化条件对温拌沥青性能的影响

Influence of Coupled Aging Condition of Heat,Light and Water on Performance of Warm Mix Asphalt

为了研究高温、紫外光辐射和雨水等自然环境因素耦合作用对温拌沥青性能的影响,研发室内加速耦合老化试验箱,采用70^#沥青分别添加有机降黏温拌剂Sasobit和表面活性温拌剂DAT,设置热、光、水耦合老化条件,采用均匀试验设计方法开展温拌沥青性能的变化规律研究。分析并确定了耦合老化条件下,影响温拌沥青老化的耦合老化因素和因素的显著性水平。结果表明:温度变化对温拌沥青老化作用最显著,光、湿度的影响相对较小。热、光、水耦合老化不是对所有性能指标影响都显著,其中,对Sasobit温拌沥青软化点、黏度产生显著性影响的是热、光耦合老化作用,水的影响不显著;对DAT温拌沥青,仅温度的作用对黏度影响显著,光、水耦合老化作用不显著,仅热、光耦合老化作用对抗车辙因子影响显著,水的作用不显著。热、水、光耦合老化条件对温拌沥青针入度、延度的影响为负相关,对软化点、抗车辙因子、抗疲劳因子的影响为正相关,即环境温度升高,光照增强、湿度增大会导致温拌沥青针入度和延度减小,软化点升高,黏度、抗车辙因子和抗疲劳因子增大,说明耦合老化作用有利于沥青的抗车辙性能和抗疲劳性能。建立了两类温拌沥青各项性能指标的耦合老化方程,通过耦合老化方程预测了老化极值及对应的耦合老化条件,证明耦合老化作用对温拌沥青的黏弹性、高温性能、疲劳性能产生了显著作用。

In order to study the coupling influence of natural environmental factors such as high temperature, ultraviolet radiation and rainwater on the performance of warm mix asphalt, an indoor accelerated coupling aging test box is developed. The organic viscosity warm mix agent Sasobit and surface activity warm mix agent DAT are added into asphalt No.70 respectively, and the coupling aging condition of heat,light and water is set up by adopting uniform experimental design method to study the change rule of warm mix asphalt’s performance. The coupling aging factors and the significant level that affect the aging of warm mix asphalt under the coupling aging condition is analyzed and determined. The result shows that(1) The change of temperature has the most significant influence on the aging of warm mix asphalt, while the change of light and humidity is relatively smaller. The coupling aging of light, heat and water does not have significant influence on all performance indicators, among them, the coupling aging of heat and light has significant influence on the softening point and the viscosity of Sasobit warm mix asphalt, but the influence of water is not significant;(2) For DAT warm mix asphalt, the influence of temperature on viscosity is significant only, and the influence of light-water coupling aging is not significant. The influence of heat-light coupling aging on anti-rutting factor is significant only, and the influence of water is not significant.(3) The influence of heat-water-light coupling aging on the penetration and the ductility of warm mix asphalt is negatively correlated, while the influence on the softening point, anti-rutting factor and anti-fatigue factor is positively correlated, i.e., rising ambient temperature, light intensity and humidity will result in decrease of penetration and ductility, increase of softening point, viscosity, anti-rutting factor and anti-fatigue factor of warm mix asphalt. It illustrates that coupled aging is beneficial to the anti-rutting performance and anti-fatigue performance of asphalt. The coupling aging equations of performance indicators of 2 kinds of warm mixed asphalt are established, and the aging extreme value and the corresponding coupling aging condition are predicted by the equations. It is proved that the coupling aging has significant influence on the viscoelasticity,high temperature performance and fatigue performance of warm mix asphalt.