摘要
针对车辆荷载引起的动水冲刷作用,设计开发了一种模拟动水冲刷的试验装置,结合冻融循环试验,对动水冲刷与静态浸水模式下沥青混合料的空隙率、吸水率以及劈裂强度等技术指标进行测试,并借助CT扫描试验,从微观的角度探讨动水冲刷作用下沥青混合料的短期水损害机理。试验结果表明:随着冻融循环次数的递增,动态冲刷浸水模式和静态浸水模式作用下的沥青混合料试件空隙率增幅分别为47.62%和22.5%;吸水率增幅分别为263.2%和86.4%,冻融劈裂强度比(TSR)降幅分别为34.0%和24.9%,动水冲刷作用会加剧沥青混合料物理和力学性能的衰退。CT图像分析表明:随着冻融循环次数的增加,混合料试件的内部产生了新的空隙,试件外缘集料存在不同程度的剥落现象;动水冲刷作用会加剧水体对沥青薄膜的机械侵蚀速率,加速沥青的剥离和细集料的流失,导致原有空隙体积的进一步增大,混合料抗水损害性能下降更为显著。
The dynamic water scouring effect caused by the vehicle load was investigated with a selfdesigned apparatus in this paper. The void ratio,water absorption and split tensile strength of asphalt mixture of AC-13 were monitored during the freeze-thaw cycle test by two different immersion modes(static immersion mode and dynamic scouring immersion mode). The microstructure changes were also tested with the aid of X-ray computed tomography(CT)to explore the mechanism of water damage of asphalt mixture both from the macroscopic and mesoscopic points of view. The experimental results show that with the increase of freezing-thawing cycles,the void rate under dynamic scouring mode and static immersion mode increases by 47.62% and 22.5%,respectively,and the water absorption rate increases by263.2% and 86.4%,respectively. The freeze-thaw splitting tensile strength ratio(TSR)declines by 34%and 24.9%,respectively. The CT images analysis reveals that new frost-heave voids are produced in the inner part of mixtures,and some of the aggregates are also spalled at the outer edge. Dynamic water scouring will accelerate the shedding of fine aggregates and expand the volume of voids correspondingly.The deterioration of the anti-water property of the mixture under dynamic water scouring was more obvious.
作者
王英
李萍
念腾飞
姜继斌
WANG Ying;LI Ping;NIAN Teng-fei;JIANG Ji-bin(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;China Municipal Engineering Northwest Design Institute,Lanzhou 730030,China)
出处
《吉林大学学报（工学版）》
EI
CAS
CSCD
北大核心
2020年第1期174-182,共9页
Journal of Jilin University:Engineering and Technology Edition
基金
国家自然科学基金项目(51868047,51668041)
兰州理工大学建工七七校友奖励基金项目(TJ2018-G04).
关键词
道路工程
沥青混合料
水损害
动水冲刷
冻融循环
空隙率
road engineering
asphalt mixture
water damage
dynamic water scour
freeze-thaw cycle
void ratio
