寒区道路Top-Down裂缝成因分析

摘要

基于Top-Down裂缝病害路段区分路况(优、中、差)现场钻取的芯样和路面板,室内分层(上、中、下面层)切割试件进行沥青抽提后三大指标试验、OT试验及小梁弯曲试验,对寒区Top-Down裂缝成因进行分析.试验结果表明,沥青结合料老化和混合料低温疲劳、低温收缩均为寒区Top-Down裂缝产生的原因.%In the disease road with Top-Down cracks,the core samples and pavement slabs are drilled and selected in different road conditions (excellent,medium and poor).The test of three major indexes (penetration,ductility,softening point) after asphalt extraction test,the OT test and the trabecular bending test are conducted on the samples cut into three layers (upper layer,middle layer,and lower layer) to analyze the cause of Top-Down cracks in cold regions.The test results show that the aging of asphalt binder,the fatigue and shrinkage at low temperature of the mixture are the causes of the Top-Down cracks formation in cold regions.