Experimental investigation on the fatigue properties of studs under the coupling of load and corrosion environment

This study investigated the influence of the coupling of load and corrosion environment on the fatigue properties of studs. Static tests were conducted on two push-out specimens, and fatigue tests were performed on six push-out specimens after three cycles of corrosion and fatigue alternation. The findings were compared with fatigue test results from push-out specimens subjected to pure corrosion. The analysis focused on the effects of the load and corrosion environment coupling on failure modes, fatigue life, fatigue crack length, and relative slip at the interface of the studs. The results indicated that the failure modes of all push-out specimens in both static and fatigue tests were stud shear failure. Shear failure occurred at the root of studs. Furthermore, the fatigue life of the studs decreased exponentially as corrosion ratios increased. An increase in the number of pre-fatigue cycles intensified the coupling effect of load and corrosion environment on fatigue life. The length of the fatigue fracture surface in the studs also exhibited an exponential decrease with increasing corrosion ratios. Additionally, higher corrosion ratios and a greater number of pre-fatigue cycles resulted in an accelerated the relative slip growth rate at the interface between concrete flange slabs and steel girders. The relative slip curve at the interface displayed a distinct two-stage development pattern: a stable growth stage and a rapid growth stage. The coupling effect of load and corrosion environment significantly enhanced the relative slip growth rate at the interface. This effect was amplified with increased pre-fatigue cycles and higher corrosion ratios, leading to a faster relative slip growth rate at the interface.