连续配筋混凝土刚柔复合式路面Top-Down开裂分析  

Top-Down crack analysis of continuously reinforced concrete and asphalt concrete composite pavement

作　　者：李盛[1] 张豪[1] 孙煜 危文康 LI Sheng;ZHANG Hao;SUN Yu;WEI Wenkang(Key Laboratory of Special Environment Road Engineering of Hunan Province,Changsha University of Science&Technology,Changsha 410114,China;Hubei Provincial Communications Planning and Design Institute Co.Ltd.,Wuhan 430051,China)

机构地区：[1]长沙理工大学特殊环境道路工程湖南省重点实验室,湖南长沙410114 [2]湖北省交通规划设计院股份有限公司,湖北武汉430051

出　　处：《中南大学学报（自然科学版）》2022年第6期2300-2310,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51878076)。

摘　　要：针对CRC+AC复合式路面Top-Down裂缝开裂问题,通过数值模拟,分析CRC+AC复合式路面Top-Down裂缝的开裂诱因,研究温度和荷载作用下沥青面层Top-Down裂缝扩展情况。研究结果表明:沥青面层纵向和横向拉应力最大值均出现在路表处,在路表2 cm以下深度,沥青面层内的拉应力逐渐转为压应力;在轮载前端和后端处,沥青面层剪应力较大且沿路表2~3 cm深度处剪应力最大,在不同深度,轮载后端比轮载前端对应的剪应力大;由于轮载前端剪应力和拉应力均较大,沥青面层在拉应力和剪应力综合作用下更易形成横向Top-Down裂缝;沥青层温度应力随深度增加而逐渐减小,且随着深度增加,最大温度应力出现时间滞后;冬季低温季节的每天6:00前后,在温度作用下,Top-Down裂缝的裂纹尖端应力强度因子达到最大值,此时裂缝最易扩展;在非均布荷载作用下,纵向裂缝的开裂主要为张开型(I型)和滑开型(II型)开裂,拉应力和剪应力是影响纵向裂缝发展的主要因素,横向裂缝的开裂主要为II型开裂,剪应力为主要影响因素。研究成果可为CRC+AC复合式路面沥青面层的开裂控制及沥青面层的合理设计提供参考依据。Aimed at CRC+AC composite pavement Top-Down cracks,through numerical simulation,the cracking inducement of Top-Down cracks in CRC+AC composite pavement was analyzed,and the propagation of TopDown cracks in asphalt pavement under the action of temperature and load was studied.The results show that the maximum longitudinal and transverse tensile stresses of the asphalt surface layer appear on the road surface,and the tensile stress in the asphalt surface layer gradually turns into a compressive stress at a depth of 2 cm or less from the surface of the road surface.The shear stress of the asphalt surface at the front and rear ends of the wheel load is larger and the shear stress is the largest at a depth of 2−3 cm along the road surface.At different depths,the rear end of the wheel load has a larger shear stress than that of the front end of the wheel load.Since the shear stress and tensile stress at the front end of the wheel load are both larger,the asphalt surface layer is more likely to form transverse Top-Down cracks under the action of tensile stress and shear stress.The temperature stress of the asphalt layer gradually decreases with the increase of the depth,and as the depth increases,the time of the maximum temperature stress will lag behind.At around 6:00 per day in winter,the stress intensity factor of the crack tip of the Top-Down crack reaches the maximum value under the action of temperature,and the crack is most likely to grow at this time.Under the action of non-uniform load,the longitudinal cracks are mainly open type(type I)and sliding type(type II)cracks.Tensile stress and shear stress are the main factors affecting the development of longitudinal cracks.The transverse cracks is mainly type II cracks,that is,the shear stress is the main influence factor.The results can provide references for the control of cracking of CRC+AC the asphalt surface of composite pavement and rational design of the surface of asphalt road.

关 键 词：道路工程 复合式路面 数值模拟 温度场 拉应力 TOP-DOWN开裂 

分 类 号：U416.221[交通运输工程—道路与铁道工程]