摘要
为了研究CRTSⅢ型板式轨道充填层自密实混凝土(Self-compacting concrete,SCC)在不同服役环境下疲劳损伤的本构关系,采用Weibull分布函数并引入残余应变表征损伤度,建立了SCC疲劳损伤的本构模型,探讨了水和动荷载共同作用对SCC疲劳损伤的影响,同时采用MTS试验机对典型充填层SCC的抗压疲劳性能进行了测试和模型验证。结果表明,基于Weibull分布和残余应变的SCC疲劳损伤本构模型能够较好地表征典型充填层SCC在疲劳荷载作用下的性能演变,本构模型的拟合结果与试验结果的相关系数大于0. 97,该模型能够较好地体现SCC的损伤随疲劳次数增加的变化。1×106次疲劳荷载后,动荷载作用下SCC极限抗压强度降低20. 5%;相比较动荷载单独作用,在饱水条件下,1×106次疲劳试验后,SCC极限抗压强度降低6. 7%;水-动荷载共同作用下SCC极限抗压强度降低27. 2%。由此可知水和动荷载共同作用加剧了SCC的疲劳损伤。
For the sake of investigating the fatigue damage of self-compacting concrete(SCC) used in CRTSⅢ slab track filling layer under diverse ser-vice environment,the Weibull distribution function was employed and the residual strain was introduced to characterize the damage degree,and the SCC fatigue damage constitutive model was established.The effects of water and dynamic load on the fatigue damage of SCC was discussed,and the compression fatigue performance of typical filling layer SCC was tested and verified by the MTS testing machine.Results indicated that the Weibull distribution and residual strain based SCC fatigue damage constitutive model could well characterize the performance evolution of typical filling layer SCC under fatigue load.The correlation coefficients between the fitted results of the constitutive model and the experimental results are larger than 0.97,which meant the model could well reflect the variation of SCC damage with the rising fatigue times.After 1×10^6 times fatigue load,the ultimate compressive strength of SCC decreased by 20.5% under dynamic load,compared with the single action of dynamic load,the ultimate compressive strength of SCC decreased by 6.7% under saturated water condition after 1×10^6 times fatigue load,the ultimate compressive strength of SCC decreased by 27.2% under the combined action of water-dynamic load.The combined action of water and dynamic load accelerated SCC damage under fatigue load.
作者
万镇昂
马昆林
龙广成
谢友均
WAN Zhen’ang;MA Kunlin;LONG Guangcheng;XIE Youjun(School of Civil Engineering,Central South University,Changsha 410075;National Engineering Laboratory of High-speed Railway Construction Technology,Central South University,Changsha 410075)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2019年第4期634-638,共5页
Materials Reports
基金
国家重点研发计划项目(2017YFB1201204)
国家自然科学基金(51678569
11790283
51678568)~~
