公路工程

沥青砂浆的疲劳特性与沥青混合料的疲劳特性密切相关，为了探究沥青砂浆的疲劳性能，以基质沥青、高模量改性沥青、SBS改性沥青3种沥青砂浆为研究对象，进行了单轴压缩动态模量试验、直接拉伸疲劳试验。基于VECD模型计算了动态模量比，建立了3种沥青砂浆的C-S疲劳特征曲线；提出了疲劳评价参数D^R,对3种沥青砂浆的疲劳损伤特性进行了评价。结果表明：C-S损伤特征曲线的相对位置可以评价沥青砂浆的抗疲劳性能，高模量改性沥青砂浆的抗疲劳性能最好，SBS改性沥青砂浆次之，基质沥青砂浆抗疲劳性能最差。疲劳评价参数D^R值的大小和虚正割模量降低速度也可以评价沥青砂浆的疲劳性能，且D^R值是一种与应变水平无关的材料常数。沥青砂浆在疲劳试验下的损伤演变过程可以由C-S曲线进行较好的描述，疲劳评价参数D^R能更好地评价不同沥青砂浆之间的疲劳性能差异。

The fatigue properties of asphalt mortar are closely related to the fatigue properties of asphalt mixture. To explore the fatigue properties of asphalt mortar.Taking base asphalt, SBS-modified asphalt, and high modulus asphalt as the research objects, the uniaxial compression dynamic modulus test, and direct tensile fatigue test was carried out; the dynamic modulus ratio was calculated based on the Viscoelastic Continuous Damage(VECD)model, and the C-S fatigue characteristic curves of three kinds of asphalt mortars were established; the fatigue evaluation parameter D^R was proposed, and the fatigue damage characteristics of three kinds of asphalt mortars were evaluated. The results show thatthe relative position of the C-S damage characteristic curve can evaluate the fatigue resistance of asphalt mortar. The high modulus asphalt mortar has the best anti-fatigue performance, followed by SBS-modified asphalt mortar, and the matrix asphalt mortar has the worst anti-fatigue performance. The magnitude of the fatigue evaluation parameter D^R and the rate of decrease in virtual secant modulus can also evaluate the fatigue performance of asphalt mortar. And the D^R value is a material constant that is independent of the strain level. The C-S curve can better describe the damage law of asphalt mortar during the fatigue test, the fatigue evaluation parameter D^R can better evaluate the fatigue performance difference between different asphalt mortars.