Shear carrying capacity of reinforced concrete beams with various a/d ratios damaged due to the Alkali-Silica reaction

This study presents experimental investigations on the shear carrying capacity of RC beams in which alkaline silica reaction (ASR) of the concrete has occurred. In the experiments, RC beams with shear span effective depth ratio, a/d = 1.0, 2.5 and 4.5 were prepared. Before conducting a loading test, visual observation and measurements of the crack and crack width were conducted using a digital microscope to quantitatively evaluate the degree of damage caused by the cracks due to the ASR. In the shear loading test, the initiation and propagation of the diagonal cracks were measured by image analysis, and simultaneously rebar strain and concrete strain were measured to calculate the neutral axis in the beam section. The experiments show that the effects of a/d ratio on the shear strength of the RC beams with different durations of outdoor exposure can be clarified based on the difference in the angle and propagation of the diagonal cracks.