基于重复加载蠕变试验的沥青混合料高温性能研究

Study on the High-temperature Performance of Asphalt Mixture Based on Repeated Load Creep Test

为了研究沥青混合料的高温蠕变特性,选取AC-13、AC-16和AC-20 3种不同类型的沥青混合料,在室内进行重复加载蠕变试验,并从蠕变曲线中提取相关的力学参数分析其变化规律,结合车辙试验结果,论证评价指标的可行性。结果表明,斜率b、组合参数εp/Fn与车辙试验指标的相关性较好,而永久应变εp和截距a与车辙试验结果的相关性较差,流动次数Fn存在局限性;对于组合试件,εp/Fn与车辙深度值的相关性最好。因此建议采用εp/Fn作为沥青混合料的高温性能评价指标,从而为沥青路面车辙预估模型的研究及混合料设计提供参考价值。

In order to study the creep properties of asphalt mixtures at high-temperatures, three different gradation asphalt mixture AC- 13 , AC- 16 and AC-20 were selected to perform the repeated load creep tests, and variation law of mechanics parameters was analyzed, combined with rutting test result, the feasibility of evaluation index was demonstrated. The experimental results show that the slope b, the ratio of permanent stain and flow Number εp/Fn have a good correlation with dynamic stability and rutting depth, but permanent strain Cp and nodal increment have a poor correlation with the results of rutting test, and flow number Fn was limited; as for composite members, εp/Fnhas good correlation with rutting depth. So εp/Fn can be used as evaluating index for high temperature performance of asphalt mixture, thus we provided a suggestion for studying rutting prediction and mixture design.