Web crushing strength of reinforced and prestressed concrete beams

The web crushing strengths of 16 reinforced and prestressed concrete I-beams are reported. The principal variables of the test specimens are the ratio of yield force in the prestressed steel to yield force in the nonprestressed steel and the area of vertical stirrups. The test strengths are compared with the upper limit on shear strength given by ACI Building Code, the Australian and Canadian standards, and the expression proposed by Nielson et al. The code proposals are found to be always conservative.