SEISMIC BEHAVIOR OF HIGH-STRENGTH CONCRETE SHORT BEAMS

Six large scale high strength concrete (HSC) model beams were tested under cyclic shear and double curvature. Experimental parameters included clear span length to section depth ratio ranging from 3.0 to 4.0 (shear span ratio of 1.5 to 2.0), longitudinal steel ratio and configuration. The stirrups were designed based on the seismic design provisions of current ACI code. All the model beams developed flexural deformation dominated responses with a displacement ductility factor of 3.0 to 6.0. The flexural strength calculated based on current ACI 318 code approach was developed or exceeded. Compared with the beams with conventional reinforcement configurations, the model beams with vertically distributed flexural reinforcements developed significantly improved hysteretic performance and ductility.