Study on the Mechanical Properties of Stud Connectors in UHPC after Fatigue
In order to study the residual mechanical properties of bolted connectors in steel-UHPC composite structures after fatigue loading,two groups of four push-out specimens were designed and fabricated for experimental study,one group of which is static load damage test,and the other one of which is static load damage test after 2 million fatigue cyclic loading.The test results show that steel-UHPC push-out specimens in the static load test and fatigue after the static load test in the stud damage mode are shear damage.After 2 million times of fatigue cyclic loading,steel-UHPC specimen shear stiffness degrades by 30%to 40%,the ultimate bearing capacity and static load test declines by about 6%,the stud bearing capacity of ordinary concrete decreases by about 23%.It can be seen that the fatigue loading has a significant effect on the shear stiffness,and its effect on the bearing capacity of steel-UHPC specimens is small,and is much smaller than the degradation level of the stud bearing capacity in ordinary concrete.