Yang Kang, He Zhaoyi, Li Dongxue, Xu Hao, Kong Lin
School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400074, China.
College of Traffic & Transportation, Chongqing Jiaotong University, Chongqing 400074, China.
Materials (Basel). 2021 Jul 23;14(15):4096. doi: 10.3390/ma14154096.
In this study, the semicircle three-point bending tests of ordinary asphalt concrete and basalt fiber asphalt concrete were carried out and acoustic emission parameters were collected during the test. The differences of the characteristics of acoustic emission parameters between basalt fiber asphalt concrete and ordinary asphalt concrete were analyzed, and the damage stages were divided based on the variation of acoustic emission parameters; Rise Angle and Average Frequency were introduced to study the cracking mode and crack resistance mechanism of asphalt concrete with basalt fiber. The results show that the acoustic emission parameters can well represent the toughening and crack resistance effect of basalt fiber in asphalt concrete, and the damage stages can be divided into three stages: microcrack initiation stage, fracture stage, and residual stage. The duration of the fracture stage and the load resistance time of the specimen were greatly prolonged. The proportion of shear events in the whole failure process increased greatly after the basalt fibers were added, especially in the fracture stage, which reduced the tensile failure tendency of the specimens, and thus improved the bending and tensile performance of the specimens and played a toughening and crack resistance role in the fracture stage.
本研究对普通沥青混凝土和玄武岩纤维沥青混凝土进行了半圆三点弯曲试验,并在试验过程中采集声发射参数。分析了玄武岩纤维沥青混凝土与普通沥青混凝土声发射参数特征的差异,基于声发射参数的变化划分损伤阶段;引入上升角和平均频率研究含玄武岩纤维沥青混凝土的开裂模式及抗裂机理。结果表明,声发射参数能很好地表征玄武岩纤维在沥青混凝土中的增韧抗裂效果,损伤阶段可分为三个阶段:微裂纹萌生阶段、断裂阶段和残余阶段。断裂阶段的持续时间和试件的承载时间大幅延长。添加玄武岩纤维后,整个破坏过程中剪切事件的比例大幅增加,尤其是在断裂阶段,降低了试件的拉伸破坏倾向,从而提高了试件的抗弯拉性能,在断裂阶段起到增韧抗裂作用。