冷补沥青混合料老化特征的宏微观性能

黄允江¹，李响²，耿立涛^3*，宋昊³，康潇涵²，苗庭选⁴

1.山东高速湖北发展有限公司，湖北 武汉  430000；2.湖北樊魏高速公路有限公司，湖北 襄阳  441123；

3.山东建筑大学交通工程学院，山东 济南  250101；4.湖北联合交通投资开发有限公司，湖北 武汉  430000

摘要：为分析老化对冷补沥青混合料界面形态和力学性能的影响，设计9组基质沥青、稀释剂和添加剂的质量比制备冷补沥青混合料，测定旋转黏度和裹覆率，确定基质沥青、稀释剂和添加剂的质量比为75∶22∶3。根据5种不同冷补沥青质量分数（3.0%、3.5%、4.0%、4.5%、5.0%）制备的冷补沥青混合料的裹覆效果，确定冷补沥青最佳质量分数为4.0%~4.5%。根据经验关系公式可确定3种级配（A、B、C）的最佳冷补沥青质量分数分别为4.3%、4.2%、4.0%。对3种不同级配的冷补沥青混合料进行间接拉伸、扫描电镜观察和纳米压痕等多尺度试验分析老化时间对其宏观力学性能和微观界面形态特性的影响。结果表明：3种级配冷补沥青混合料的间接拉伸模量均随老化时间的增大而增大；采用最佳沥青质量分数4.3%制备的级配A冷补沥青混合料经长期老化后间接拉伸模量仍较大，微观界面形态光滑，集料部分的弹性模量变化极小，界面处及沥青胶浆的弹性模量均随老化时间的增大而增大。沥青胶浆的弹性模量在老化初期迅速增大，后期趋缓。

关键词：冷补沥青混合料；老化时间；间接拉伸模量；微观界面特性

Macro and micro properties of cold patching asphalt mixture

HUANG Yunjiang¹, LI Xiang², GENG Litao^3*, SONG Hao³, KANG Xiaohan², MIAO Tingxuan⁴

1.Shandong High-Speed Hubei Co., Ltd., Wuhan 430000, China; 2.Hubei Fan-Wei Expressway Co., Ltd., Xiangyang 441123, China;

3.School of Transportation Engineering, Shandong Jianzhu University, Jinan 250101, China;

4.Hubei United Transportation Investment & Development Co., Ltd., Wuhan 430000, China

Abstract: To analyze the effects of aging on the interface morphology and mechanical properties of cold patching asphalt mixtures, nine groups of quality ratios of matrix asphalt, diluents, and additives are designed to prepare cold patching asphalt mixtures, measuring the rotational viscosity and coating rate, determining the quality ratio of matrix asphalt, diluents, and additives to be 75:22:3. Based on the coating effects of cold patching asphalt mixtures prepared with five different quality percentages of cold patching asphalt, the optimal quality percentage of cold patching asphalt is determined to be 4.0% to 4.5%. According to empirical relationship formulas, the optimal quality percentages of cold patching asphalt for three different gradations are determined to be 4.3%, 4.2%, and 4.0%, respectively. Three different gradations of cold patching asphalt mixtures undergo indirect tensile, scanning electron microscopy, and nano-indentation tests to analyze the effects of aging time on their macroscopic mechanical properties and microscopic interface morphological characteristics. The results show that the indirect tensile modulus of the three gradations of cold patching asphalt mixtures increase with the increase of aging time; the gradation A cold patching asphalt mixture prepared with the optimal asphalt quality percentage of 4.3% maintain a relatively high indirect tensile modulus after long-term aging, exhibiting a smooth microscopic interface morphology, minimal change in the elastic modulus of the aggregate portion, and an increase in the elastic modulus at the interface and asphalt mastic with increased aging time. The elastic modulus of the asphalt mastic rapidly increase in the early stages of aging and then leveled off in the later stages.

Keywords: cold patching asphalt mixture; aging time; indirect tensile modulus; micro-interface characteristic