Static and fatigue behavior of large stud shear connectors for steel-concrete composite bridges

For the design of shear connection in high shear areas of steel-concrete composite bridges, large shear studs can be an excellent alternative. Through the push-out tests on large stud shear connectors up to 30 mm diameter, which are beyond the limitation of current design codes, static and fatigue behavior was investigated and compared with design equations. The ultimate strength of the shear connection showed that the design shear strength in Eurocode-4 and AASHTO LRFD gives conservative values for large studs. The fatigue endurance obtained from the tests was slightly lower than the current design codes in Eurocode-4. Based on the push-out test results on large studs, partial composite beams with about 38% degree of shear connection were fabricated and static tests were performed. The ultimate strength and horizontal shear load redistribution of partial composite beams, which had parameters of stud shank diameters and distribution, were evaluated and group failure in shear span was observed. The ultimate strength of the shear connection had a value about 1.59 times larger than that from push-out tests.