缓裂加强型应力吸收层动态响应与变形研究

Research on Dynamic Response and Deformation of Stress Absorption Layer with Slow Cracking and Reinforcement

沥青路面层间结合状态及力学响应一直是路面研究领域的热点问题。依托河北省建设厅重大科技攻关项目,结合力学分析法与黏弹性理论,通过在两种应力吸收层上铺设应变传感器的手段,分析了不同荷载、车速及温度工况下两种应力吸收层的动态响应规律。结果表明,沥青路面作为黏弹性体,实测结果与黏弹性层状理论解一致,两应力吸收层均受压。荷载试验表明,两路段应变增幅之比从静载的0.496减小至80km/h动载的0.234,说明土工格栅在动载情况下加筋作用更明显;根据现场试验,提出了缓裂加强型应力吸收层关于速度和温度(标准轴载)的两个动态响应模型;由于缓裂加强型应力吸收层中土工格栅的加筋作用,荷载、车速和温度均对其影响更小,表明其性能更好。研究结果对于提升河北省半刚性道路的路用性能具有一定的理论指导意义。

The interlayer combination and mechanical response of asphalt pavement have been hot topics in the field of pavement research.In the paper,relying on the major science and technology projects of Hebei Provincial Department of Construction and combining with mechanical analysis and viscoelastic theory,by laying strain gauge on two kinds of stress absorption layers,the dynamic response law of two kinds of stress absorption layers under different load,speed and temperature are analyzed.The results show that,asphalt pavement being viscoelastic,the measured results are consistent with the theoretical solution of layered viscoelastic,both stress absorbing layers are affected by pressure.Load tests show that the strain growth ratio of the two sections decrease from 0.496 under static load to 0.234 under dynamic load of 80 km/h,which indicates that the reinforcement effect of geogrid is more obvious under dynamic load.According to the field tests,two dynamic response models of the reinforced stress absorber layer with respect to velocity and temperature(standard shaft load)are proposed.The effect of load,speed and temperature on the reinforced stress absorbing layer is less due to the reinforcing effect of geogrid,which indicates that the pavement performance of the reinforced stress absorbing layer is better.The research results have important theoretical significance for improving the pavement performance of semi-rigid roads in Hebei Province.