Shear Capacity of Stub‐Girders: Full Scale Tests

Abstract

This paper briefly summarizes some of the results of tests on three full‐size stub‐girders. The objectives of the investigation were to study the failure mechanism and to evaluate the effectiveness of three different types of transverse slab reinforcement in increasing the longitudinal shear capacity. Deflection characteristics and general structural behavior were also studied. In all cases, failure involved crushing of the slab over the interior end of the end stub accompanied by a shear/splitting failure in the slab over the length of the end stub. The observed ultimate load on the stub‐girders exceeded the design ultimate load by 45%, 14% and 21% respectively for Specimens K‐1, K‐2 and K‐3. Straight transverse reinforcing bars in addition to temperature and shrinkage reinforcement, had little effect on the stub‐girder capacity. The incorporation of a wide concrete flute along the slab centerline, together with bent transverse bars significantly increased the ultimate capacity and improved the ductility of the stub‐girder. The specimens tested were very stiff and would meet normal deflection requirements under service loads.