PERFORMANCE OF HIGH-STRENGTH CONCRETE CORBELS

In this study, 30 high-strength concrete corbels were tested to destru ction. Variables considered in the investigation are shear span-to-dep th ratio, concrete strength (45 to 105 MPa [6500 to 15,200 psi), and t he provision of secondary reinforcement. The investigation examines co rbel behavior in the context of the previous parameters and compares t he experimental results with the ACI 318-89 design method and the plas tic truss model of Rogowsky and MacGregor. Particular attention is giv en to determining the concrete efficiency factor for members Sailing i n compression, and the results ave compared with the efficiency model proposed by Warwick and Foster The results of the investigation show t hat good load predictions can be obtained using the plastic truss mode l when combined with the Warwick and Foster efficiency factor. It is c oncluded that the design method given in ACI 318-89 is not appropriate for coubels fabricated using high-strength concrete.