Static and fatigue behaviors of short stud connectors embedded in ultra-high performance concrete

Abstract

Ultra-high performance concrete (UHPC) has been increasingly applied in steel–concrete composite structures for high carrying efficiency and durability. Shear connectors play a vital role in maintaining the composite action in composite structures. This study experimentally investigated the static and fatigue behaviors of short stud connectors embedded in UHPC. Ten push-out specimens were tested, including three static and seven fatigue tests. Static tests were conducted to determine the shear capacity and load-slip behavior of the studs. Fatigue tests were performed to investigate the fatigue crack modes, fatigue strength, and degradation of the mechanical behavior of the studs. Based on the test results, the evaluation formulas of the shear capacity and load-slip curve of studs in the existing literature were compared, and reasonable formulas were suggested. The nominal SN curve and prediction formulas for the evolution of plastic slip and elastic stiffness were established. Furthermore, a parametric numerical analysis was performed to investigate the effect of the modulus of UHPC on the fatigue behavior of stud connectors.