加铺小粒径大孔隙沥青混合料薄层罩面的路面结构力学响应分析

Analysis on Mechanical Response of Pavement Structures Paved with Thin-layer Overlay of Small-size Large-pore Asphalt Mixture

摘要:

为探究小粒径大孔隙沥青混合料SLAM薄层罩面的工程应用可行性，采用动态模量表征动态荷载条件下SLAM材料性能，并基于ABAQUS有限元软件仿真分析不同SLAM类型及罩面层厚度条件下加铺SLAM薄层罩面的路面结构力学响应规律。结果表明：SLAM具有良好的高温稳定性、低温抗裂性、水稳定性、抗滑性能和排水性能；相比SLAM-II，SLAM-I的动态模量较小，动态模量和相位角更易受到荷载频率的影响；加铺SLAM薄层罩面可以提高原有路面各结构层的抗裂性能，且对中面层横向抗裂的改善效果优于纵向抗裂；与加铺SLAM-I薄层罩面的路面结构相比，加铺SLAM-II薄层罩面的路面结构中罩面层底纵向最大应力、横向最大应力、层间剪应力水平均较高，应采取针对性措施来保证罩面层与表面层之间的层间安全，在工程应用中应尽量选择模量低的SLAM类型。

Abstract:

In order to explore the feasibility of the engineering application of small-size large-pore asphalt mixture (SLAM) thin-layer overlay, the dynamic modulus is adopted to characterize the material performance of SLAM under dynamic loading conditions, and based on the ABAQUS finite element software, the mechanical response rule of the pavement structure paved with SLAM thin-layer overlay under the different SLAM types and overlay layer thickness conditions are simulated and analyzed. The results show that SLAM has the good high-temperature stability, low-temperature crack resistance, water stability, anti-skid performance and drainage performance. Compared with SLAM-II, the dynamic modulus of SLAM-I is smaller, and the dynamic modulus and phase angle are more likely to be affected by the load frequency. The addition of SLAM thin-layer overlay can improve the cracking resistance of the original pavement structural layers, and the improvement effect of transverse cracking of the middle layer is better than the longitudinal cracking. Compared with the pavement structure paved with SLAM-I thin-layer overlay, the maximum longitudinal stress at the bottom of the overlay layer, the maximum transverse stress, and the level of interlayer shear stress are higher in the pavement structure paved with SLAM-II thin-layer overlay. The targeted measures should be taken to ensure the interlayer safety between the overlay layer and the surface layer. The type of SLAM with low modulus should be selected as much as possible for the engineering application.