ABSTRACT
Ultra high-performance concrete (UHPC) provides much higher compressive and tensile strength than conventional concrete. As a result of the high strength of UHPC, a UHPC-steel composite deck system can be used in longer span bridges than a conventional steel-concrete composite deck system. This paper experimentally investigated the static behaviours of headed stud embedded in UHPC. Two different connection types of headed studs including welded stud and demountable stud were used in the study. A total of 18 push out test specimens were carried out to investigate the effects of stud connection types, stud aspect ratios and stud diameters on the structural behaviours of headed studs embedded in UHPC. The failure modes, load-slip curves, ultimate shear strength and stiffness were evaluated and compared. The comparison results shown that the ultimate strength of demountable studs were less than the traditional welded studs with the same diameter. Whereas, the ductility of demountable studs was better that the welded stud. Based on the test results, equations were also developed to predict the shear strength of demountable headed stud embedded in UHPC. Comparisons between the prediction results and test results of strength were also made.
