Volume 17, Issue 4 (July 1989)
Precompressed Concrete Corbels
Very short members such as concrete brackets, corbels, and ledger beams are exposed to direct shear force. While much research has been done on reinforced concrete corbels, experimental data on the performance of precompressed concrete corbels and high-strength concrete corbels are limited. This study was designed to verify the shear-friction theory of design as suggested in the American Concrete Institute (ACI) Code. Nine corbels, divided into three series with the average concrete strength ranging between 33.23 MPa (4820 psi) and 65.72 MPa (9530 psi), were subjected to varying compressive forces and light confining steel. The corbels were loaded monotonically to failure and studied at the California State University at Fullerton. In all cases, the shear span to depth ratio (a/d) was less than 0.5. Incremental static load was gradually applied until the specimen failed. The study indicated that the ACI Code provisions are conservative and the shear friction theory needs modification.