沥青混合料断裂-微波自愈合影响因素分析

为分析沥青混合料断裂-微波自愈合性能的影响因素,分别对沥青材料和集料进行微波加热试验,采用70#基质沥青和苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrene-butadiene-styrene, SBS)改性沥青,制备AC-13型半圆试件,通过半圆弯曲试验和微波加热对试件进行断裂-愈合-断裂试验,以愈合前和愈合后加载试验的抗拉强度比值作为愈合指数(H),分析了沥青混合料微波加热行为以及损伤程度、微波强度、加热时间对自愈合性能的影响。结果表明:微波主要作用于矿质集料,并通过集料颗粒升温传热实现混合料整体升温;微波强度对沥青混合料自愈合性能的影响最为显著,其次是加热时间,随微波强度、加热时间的增长,混合料自愈合能力增强;损伤程度对自愈合性能有不利影响,但影响程度较弱。

Analysis on Influence Factors of Asphalt Mixture Fracture Microwave-Healing performance

In order to analyze the influence factors of fracture microwave-healing performance of asphalt mixtures, microwave heating test was carried out on bitumen and aggregates respectively. AC-13 semi-circular specimens were prepared with 70 # base asphalt and SBS modified asphalt, and fracture-healing-fracture test was carried out on specimens via semi-circular bending test and microwave heating. The ratio of tensile strength before and after healing loading test was used as healing index (HI). The microwave heating performance and effects of damage degree, microwave strength and heating time on self-healing performance of asphalt mixture were analyzed. The results show that microwave was mainly absorbed by aggregates, and through the heating and heat transfer of aggregate particles, the overall heating of the mixture is realized. The effect of microwave intensity on the self-healing performance is the most significant, followed by heating time. The self-healing ability of asphalt mixture increases with microwave intensity and heating time. The injury degree has a negative effect on self-healing performance, but the effect is weak.