摘要
In order to clarify the fatigue damage evolution of concrete exposed to flexural fatigue loads,ultrasonic pulse velocity(UPV),impact-echo technology and surface electrical resistance(SR) method were used.Damage variable based on the change of velocity of ultrasonic pulse(Du) and impact elastic wave(Di)were defined according to the classical damage theory.The influences of stress level,loading frequency and concrete strength on damage variable were measured.The experimental results show that Du and Di both present a three-stages trend for concrete exposed to fatigue loads.Since impact elastic wave is more sensitive to the microstructure damage in stage Ⅲ,the critical damage variable,i e,the damage variable before the final fracture of concrete of Di is slightly higher than that of Du.Meanwhile,the evolution of SR of concrete exposed to fatigue loads were analyzed and the relationship between SR and Du,SR and Di of concrete exposed to fatigue loads were established.It is found that the SR of concrete was decreased with the increasing fatigue cycles,indicating that surface electrical resistance method can also be applied to describe the damage of ballastless track concrete exposed to fatigue loads.
作者
杨志强
李化建
WEN Jiaxing
DONG Haoliang
HUANG Fali
WANG Zhen
YI Zhonglai
YANG Zhiqiang;LI Huajian;WEN Jiaxing;DONG Haoliang;HUANG Fali;WANG Zhen;YI Zhonglai(Railway Engineering Research Institute,China Academy of Railway Science Corporation Limited,Beijing 100081,China;State Key Laboratory for Track System of High-Speed Railway,Beijing 100081,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)
基金
Funded by the National Natural Science Foundation of China(Nos.U1934206,52208299,and 52108260)
the 2021 Tencent XPLORER PRIZE。
