Wang Lijun, Cheng Peifeng, Zhao Qiang
School of Civil Engineering and Transportation, Northeast Forestry University, Harbin 150040, China.
Materials (Basel). 2023 Sep 24;16(19):6382. doi: 10.3390/ma16196382.
In order to study the self-healing performance of macroscopic fractures of asphalt mixtures, semicircular bending (SCB) tests were used to test 90# base asphalt mixtures, SBS (Styrene-Butadiene-Styrene) modified asphalt mixtures, and SBS + CR (Chloroprene Rubber) composite modified asphalt mixtures. The F-H-F (the asphalt mixture specimen was fatigued for a certain number of times, then healed under certain conditions, and then fatigued until destroyed) test was carried out, and the fatigue life recovery rate of the fatigue test before and after healing was defined as the healing index (HI). The gray correlation analysis method was used to judge the influence degree of influencing factors on fatigue-healing according to the correlation index. The results show the type of asphalt has the most significant influence on the healing ability of the asphalt mixture. In the case of complete healing, the fatigue-healing performance of the SBS + CR composite modified asphalt mixture was the best, followed by the SBS-modified asphalt mixture, and 90# base asphalt. When the healing temperature is close to the softening point of asphalt, the healing performance of 90# base asphalt is better when the healing temperature is low. When the healing time is longer, the healing performance is better, and there is an optimal healing time. The healing index decreased with the increase in the degree of damage. When the degree of damage is too large, the asphalt mixture will be difficult to heal.
为研究沥青混合料宏观裂缝的自愈性能，采用半圆弯曲（SCB）试验对90#基质沥青混合料、SBS（苯乙烯-丁二烯-苯乙烯）改性沥青混合料以及SBS+CR（氯丁橡胶）复合改性沥青混合料进行测试。开展了F-H-F（沥青混合料试件先疲劳一定次数，然后在一定条件下愈合，接着再次疲劳直至破坏）试验，并将愈合前后疲劳试验的疲劳寿命恢复率定义为愈合指数（HI）。利用灰色关联分析法根据关联度指标判断影响因素对疲劳愈合的影响程度。结果表明，沥青类型对沥青混合料的愈合能力影响最为显著。在完全愈合的情况下，SBS+CR复合改性沥青混合料的疲劳愈合性能最佳，其次是SBS改性沥青混合料，90#基质沥青最差。当愈合温度接近沥青软化点时，愈合温度较低时90#基质沥青的愈合性能较好。愈合时间越长，愈合性能越好，且存在一个最佳愈合时间。愈合指数随损伤程度的增加而降低。当损伤程度过大时，沥青混合料将难以愈合。
