不同基层开裂状态的沥青路面应力对比

为比较基层裂缝形态不同时,湿度和温度变化所引起的面层及基层内应力的变化情况,采用三维有限元方法建立了含不同深度、宽度与间距基层裂缝的路面模型,采用实测的基层有限元参数,分析处于不同开裂状态的水泥稳定碎石基层沥青路面在失水和降温时,基层内的最大应力与应力分布情况,以及对沥青面层的影响。分析结果表明:对于新铺筑的基层,因失水引起的收缩应力较温差的影响更为显著;其他条件一致时,基层模量为4000MPa左右时,对于减少基层开裂最有利;无论对于失水还是降温条件,各结构层自身的模量是影响其应力的最显著因素;基层与底基层间粘结不好时,面层底部的拉应力比层间完全连续时更大,基层裂缝更易反射至面层。

Stress comparison of asphalt pavements with different base crack states

In order to compare the stress varieties in surface and base caused by different humidities,temperatures and base crack states,pavement models with different crack depthes,widthes and spaces were established by 3D finite element method. Using the test parameters of base,the maximum stress,stress distribution and the influence on asphalt pavement were analyzed under water losing condition and temperature decreasing condition for cement stabilized macadam base asphalt pavements with different base crack states. Analysis result indicates that,for new base,the influence of water losing on shrinkage stress is more remarkable than that of temperature dropping; it is the most favorable condition for reducing base crack when base modulus is about 4 000 MPa; whether water losing or temperature decreasing,the most marked factor of influencing structural stress is each layer-self modulus; when joint state between base and sub-base is bad,the tensile stress in surface bottom is larger than that in continuum state,and base crack easily reflects to pavement surface. 6 tabs,4 figs,15 refs.