Abstract
In recent years, steel-concrete composite cable-pylon anchorages are increasingly employed in the construction of long-span cable-stayed bridges, especially in China. Welded stud connectors, typically 19 mm and 22 mm in diameter, are usually densely arranged at the interface between the steel anchorage box and the wall of the concrete pylon to transfer the huge cable force into the concrete pylon. However, dense welded stud arrangements at the interface have some disadvantages, such as the shear strength reduction of stud connectors and the difficulties in arranging reinforcements and pouring pylon concrete. Larger diameter and higher strength welded studs may be excellent alternatives since they both could increase the shear strength of a single stud connector and thus reduce the required number of welded studs. In this paper, push-out tests were implemented on four groups of welded stud connector specimens, including conventional 22 mm welded studs, 22 mm welded studs with much higher strength, 25 mm welded studs, and 30 mm welded studs. The shear strength, shear stiffness, and ductility of these welded stud connectors were investigated and compared with the predictions by the equations recommended in existing design codes. The results show that the shear strength of welded stud connectors could be conservatively determined by Eurocode 4, while AASHTO LRFD will produce a suitable estimation. The load-slip relationships proposed by Ollgaard and Buttry can be used to predict the load-slip curves of large diameter and high strength welded stud connectors.
Highlights
Welded studs are the most practical connectors for achieving the composite action between steel girders and concrete slabs owing to their rapid welding technique and outstanding mechanical performance
Fourteen push-out tests were carried out to investigate the shear performance of large diameter and high strength welded stud connectors. e shear strength, shear stiffness, peak slip, and load-slip relationship of these welded stud connectors were examined and compared with the existing design codes or prediction equations. e following conclusions can be drawn: (1) e ductile failure mode could be achieved for large diameter and high strength welded stud connectors when the same welding technique and concrete strength used for conventional welded stud connectors are employed
(2) e average shear strength of Group SN25, SN30, and SH22 welded stud connectors are about 17%, 48%, and 22% larger than that of Group SN22, respectively, confirming that using large diameter or high strength welded studs increases the shear strength of a welded stud connector. e shear strength of large diameter and high strength welded stud connectors could be accurately estimated by AASHTO LRFD [19] as the conventional welded stud connectors
Summary
Welded studs are the most practical connectors for achieving the composite action between steel girders and concrete slabs owing to their rapid welding technique and outstanding mechanical performance. E mechanical performance of welded studs with 19 mm and 22 mm in diameter has been investigated by many researchers. Pallares and Hajjar [4, 5] reviewed a large number of push-out and pull-out tests on welded stud connectors and proposed formulas for the limit states of welded stud connectors subjected to shear force, tension force, and combined tension and shear force. Lin et al [6] investigated the behavior of welded stud connectors subjected to combined tension and shear loads, and an improved shear-tension interaction strength equation was recommended
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
