Li Xu, Chen Jie, Mao Shuxing, Liu Chaochao
Guangxi Xinfazhan Commnications Group Co., Ltd., Nanning 530201, China.
Department of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha 410114, China.
Materials (Basel). 2025 Aug 5;18(15):3670. doi: 10.3390/ma18153670.
With the rapid increase in traffic volume and the number of heavy-duty vehicles, the load on asphalt pavements has increased significantly. Especially on sections with long longitudinal slopes, the internal stress conditions of asphalt pavement have become even more complex. This study aims to investigate the thermal-mechanical coupling behavior of asphalt pavement structures on long longitudinal slopes under the combined influence of temperature fields and moving loads. A pavement temperature field model was developed based on the climatic conditions of Nanning (AAT: 21.8 °C; Tmax: 37 °C; Tmin: 3 °C; AAP: 1453.4 mm). In addition, a three-dimensional finite element model of asphalt pavement structures on long longitudinal slopes was established using finite element software. Variations in pavement mechanical responses were compared under different vehicle axle loads (100-200 kN), slope gradients (0-5%), braking coefficients (0-0.7), and asphalt mixture layer thicknesses (2-8 cm). The results indicate that the pavement structure exhibits a strong capacity for pressure attenuation, with the middle and lower surface layers showing more pronounced stress reduction-up to 40%-significantly greater than the 6.5% observed in the upper surface layer. As the axle load increases from 100 kN to 200 kN, the internal mechanical responses of the pavement show a linear relationship with load magnitude, with an average increase of approximately 29%. In addition, the internal shearing stress of the pavement is more sensitive to changes in slope and braking coefficient; when the slope increases from 0% to 5% and the braking coefficient increases from 0 to 0.7, the shear stress at the bottom of the upper surface layer increases by 12% and 268%, respectively. This study provides guidance for the design of asphalt pavements on long longitudinal slopes. In future designs, special attention should be given to enhancing the shear strength of the surface layer and improving the interlayer bonding performance. In particular, under conditions of steep slopes and frequent heavy vehicle traffic, the thickness and modulus of the upper surface asphalt mixture may be appropriately increased.
随着交通流量和重型车辆数量的迅速增加，沥青路面的负荷显著增大。特别是在长纵坡路段，沥青路面的内部应力状况变得更加复杂。本研究旨在探讨在温度场和移动荷载共同影响下，长纵坡沥青路面结构的热-力学耦合行为。基于南宁的气候条件（年平均气温：21.8℃；最高气温：37℃；最低气温：3℃；年降水量：1453.4毫米）建立了路面温度场模型。此外，使用有限元软件建立了长纵坡沥青路面结构的三维有限元模型。比较了不同车轴荷载（100 - 200千牛）、坡度（0 - 5%）、制动系数（0 - 0.7）和沥青混合料层厚度（2 - 8厘米）下路面力学响应的变化。结果表明，路面结构具有较强的压力衰减能力，中、下表面层的应力减小更为明显——高达40%，显著大于上表面层观测到的6.5%。当车轴荷载从100千牛增加到200千牛时，路面的内部力学响应与荷载大小呈线性关系，平均增加约29%。此外，路面的内部剪应力对坡度和制动系数的变化更为敏感；当坡度从0%增加到5%且制动系数从0增加到0.7时，上表面层底部的剪应力分别增加12%和268%。本研究为长纵坡沥青路面的设计提供了指导。在未来设计中，应特别注意提高表面层的抗剪强度和改善层间粘结性能。特别是在陡坡和重型车辆频繁通行的条件下，可适当增加上表面沥青混合料的厚度和模量。
