沥青路面加铺层的热稳定性与计算模型

Thermal Stability Performance and Calculation Model of Asphalt Pavement Overlay

以双向土工格栅合成材料为沥青路面加铺层,采用有限元软件模拟双向土工格栅结构的温度场,计算其热物性参数、温度场和温度应力的变化,以此分析其热稳定性能。结果表明:加铺层的表面存在极大的温度应力,降低加铺层的温度应力,可提升合成材料的弹性模量;加铺层的铺设深度应在0.5 m以上,以此能够发挥加铺层提升沥青路面承载力的作用;降低合成材料的热传导率能够降低加铺层的降温速率,对于裂缝应力集中现象具有缓解作用;铺设加铺层后的沥青路面的承载力和使用寿命明显延长。

Taking bidirectional geogrid composite material as asphalt pavement overlay,the thermal stability of bidirectional geogrid structure is analyzed by calculating its thermophysical parameters,the changes of temperature field and temperature stress.The results show that there is a great temperature stress on the surface of the overlay,the elastic modulus of the composite can be improved by reducing the temperature stress of the overlay.The paving depth of the overlay shall be more than 0.5 m,so as to play the role of overlay to enhance the bearing capacity of asphalt pavement.Reducing the thermal conductivity can reduce the cooling rate of the overlay,which can alleviate the phenomenon of crack stress concentration.The bearing capacity and service life of asphalt pavement are obviously prolonged after laying overlay.