全厚式沥青路面材料抗疲劳性能及疲劳预估模型

王其峰¹，吴文娟²，申全军³，徐钦升^2*，齐辉¹

1.山东高速集团有限公司，山东 济南  250101；2.山东省交通科学研究院，山东 济南  250102；

3.山东高速集团创新研究院，山东 济南  250000

摘要：为延长沥青路面的运营寿命，改善路面材料的抗疲劳性能，通过四点弯曲疲劳试验分析评价全厚式沥青路面各结构层材料的抗疲劳性能，并结合试验数据修正基于沥青饱和度、应变和劲度模量的疲劳预估模型，建立适用于全厚式沥青路面的疲劳预估模型。研究结果表明：相同试验条件下，不同类型沥青混合料的抗疲劳性能及其对应变的敏感性存在明显差异；沥青混合料的抗疲劳性能与沥青种类、沥青混合料的最大粒径有关，对比同粒径AC-25（选用70#沥青，空隙率为4.3%）和LSPM-25（选用SBS改性沥青，空隙率为15.3%），不同应变下，AC-25的疲劳寿命比LSPM-25分别约降低38.4%、28.8%、15.1%、39.5%，SBS改性沥青可有效提升粗粒式混合料的抗疲劳性能；修正后疲劳预估模型的预估疲劳寿命与试验实测结果的相关系数为0.991 6，疲劳预估模型能较准确地预测全厚式沥青路面的疲劳寿命。因此，可为有效提升沥青路面的抗疲劳性能提供可靠的理论依据。

关键词：全厚式沥青路面；四点弯曲；抗疲劳性能；疲劳预估模型

Fatigue performance and prediction model of full-thickness asphalt pavement materials

WANG Qifeng¹, WU Wenjuan², SHEN Quanjun³, XU Qinsheng^2*, QI Hui¹

1.Shandong Hi-speed Group Co., Ltd., Jinan 250101, China；2.Shandong Transportation Institute, Jinan 250102, China；

3. Shandong Hi-speed Group Innovation Research Institute, Jinan 250000, China

Abstract:In order to prolong the life span of asphalt pavement and improve the anti-fatigue performance of pavement materials, the fatigue performance of each structural layer material of full-thickness asphalt pavement is analyzed and evaluated through four-point bending fatigue test. Combined with the test data, the fatigue prediction model based on asphalt saturation, strain level and stiffness modulus is modified, and a fatigue prediction model suitable for full-thickness asphalt pavement is established. The research results show that under the same test conditions, there are obvious differences in the fatigue resistance of different types of asphalt mixtures and their sensitivity to the change of strain level. The fatigue performance of asphalt mixture is related to the type of asphalt and the maximum particle size of asphalt mixture. Compared AC-25 (70# asphalt with a void ratio of 4.3%) with LSPM-25 (SBS modified asphalt with a void ratio of 15.3%) with the same particle size, under the same strain level, the fatigue life of AC-25 is about 38.4%, 28.8%, 15.1%, and 39.5% lower than that of LSPM-25, respectively. SBS modified asphalt can effectively improve the fatigue resistance of coarse-grained mixture. The correlation coefficient between the estimated fatigue life of the revised fatigue prediction model and the test results is 0.991 6. Fatigue prediction model can more accurately predict the fatigue life of full-thickness asphalt pavement and provide a reliable theoretical basis for asphalt pavement design.

Keywords: full-thickness asphalt pavement; four-point bending fatigue test; anti-fatigue performance；fatigue prediction model