基于耗散能法分析热拌及温拌再生SMA沥青混合料的疲劳特性

Evaluation on Fatigue Properties of Hot and Warm Recycled SMA Mixture Based on Energy Dissipation Method

为了分析废旧沥青路面材料(reclaimed asphalt pavement,RAP)掺量和Sasobit对再生沥青玛蹄脂碎石混合料(stone mastic asphalt,SMA)疲劳性能的影响,本文设计并比较了不同RAP掺量(0%、20%、30%)的热拌及温拌SMA沥青混合料.对不同类型SMA沥青混合料进行四点梁弯曲疲劳试验,采用耗散能法分析其疲劳特性.研究表明:1)不同类型SMA沥青混合料的疲劳次数与累计耗散能之间的关系不会随RAP掺量改变以及是否添加Sasobit发生变化,其疲劳寿命与累计耗散能在双对数下,均表现出良好的线性关系,且具有唯一的关系方程.2)随着RAP掺量的增加,再生SMA沥青混合料的累积耗散能降低,疲劳寿命下降.3)Sasobit对温拌SMA沥青混合料耗散能量的能力有不利影响,而对温拌再生SMA沥青混合料影响不大.

In order to evaluate the influence of the reclaimed asphalt pavement ( RAP) content and Sasobit on fatigue properties of the recycled SMA mixtures, the hot and warm recycled SMA mixtures with different RAP contents(0% ,20% ,30% ) were designed and compared in this paper. Four-point bending fatigue test was conducted on the different SMA mixtures, and the energy dissipation method was employed to analyze the fatigue properties of the different SMA mixtures. It shows that the relationship between the fatigue times and cumulative energy dissipation of the recycled SMA mixtures does not change with the variation of RAP content and Sasobit. In a treble logarithmic coordinate, there is a good linear relationship between the fatigue life and cumulative dissipated energy of the recycled SMA mixtures, which can be represented by a unique relation equation. With the increase of RAP, cumulative energy dissipation and mixture fatigue life decrease. Meanwhile, Sasobit has an adverse impact on the recycled SMA mixtures without RAP, but has little influence on the recycled SMA mixtures with RAP.