The study, written by Yu-Chen Ou and An-Nhien Truong, investigated the shear and flexural behaviour of seven full-scale L- and T-columns using lateral cyclic loading.
ACI says, based on test observations, a new way of calculating the effective shear area that includes the contribution of the overhanging flange was proposed for L- and T-columns.
“The proposed effective shear area combined with the shear strength equations for columns of the ACI Code not only produced shear strengths that were more reasonably conservative but also showed less scatter than the current ACI Code method,” the institute adds.
Both columns were designed with a sufficient amount of shear reinforcement determined by the proposed shear strength equations showed flexural, ductile behaviour with ductility capacities ranging from 6.1 to 7.6.
Test results showed that the ACI 319 code was conservative for the nominal flexural strength but unconservative for the maximum probable moment strength, ACI concludes.