CRTSⅢ型板式轨道充填层SCC在水-动荷载作用下的性能变化

Performance evolution of SCC under the water-dynamic load used in CRTSIII slab ballastless track filling layer

采用MTS试验机对典型板式轨道充填层用自密实混凝土(self-compacting concrete,SCC)进行抗压疲劳测试,分析在动荷载、动荷载+饱水2种条件下,SCC动态性能、吸水率、抗压强度以及残余应变等参数的变化。研究结果表明:随着动荷载次数的增加,各组SCC动态性能和抗压强度均降低,而吸水率和残余应变均增大。SCC在动荷载作用100万次时,动荷载+饱水组较动荷载单独作用组的动态弹性模量、动态剪切模量、动态泊松比和抗压强度分别降低了4.5%,2.4%,5.2%和6.7%,而纵向残余应变增大了8.9%,横向残余应变增大了6.4%,疲劳损伤度D增大了2.4%。水和动荷载的共同作用加速了SCC性能的劣化。

The compressive fatigue test of typical self-compacting concrete(SCC)used in slab track filling layer was carried out by using MTS test machine.Changes of dynamic performance,water absorption rate,compressive strength and residual strain of SCC under dynamic load and water-dynamic load were investigated.Results show that with the number of dynamic loads increasing,the dynamic properties and compressive strength of SCC decrease,but the water absorption rate and residual strain increase.Compared with the effect of dynamic load only,water-dynamic load decreases dynamic elastic modulus,dynamic shear modulus,dynamic Poisson's ratio and compressive strength of SCC by 4.5%,2.4%,5.2%and 6.7%,respectively,but increases the longitudinal residual strain and transverse residual strain by 8.9%and 6.4%,at the same time increases the fatigue damage degree D by 2.4%.As a result,the water-dynamic load accelerates the performance deterioration of SCC.