Behavior of reinforced concrete beams with shear-span vertical openings at different positions

Abstract

Vertical openings are often incorporated into Reinforced Concrete (RC) beams to accommodate various services and necessities. However, there is limited research concerning the optimal position to pass these openings along the beam’s span. In this experimental study, four RC beams were tested under symmetric four-point bending to failure, one reference beam without an opening and three beams with vertical openings. The main parameters investigated were the presence of the opening and the effect of its specific position within the shear span. The results showed that the presence of vertical openings in the shear span caused a reduction in cracking load by 1.96-23.53%, ultimate load by 2.07-18.26%, and energy dissipation capacity (EDC) by 16.20-47.17%, with BC-SU which had an opening near the support exhibiting the least impactful effect, followed by BC which had an opening in the center of the shear span, while BC-LO which had an opening near the load point experiencing the highest reduction in strength and EDC, in addition to causing a failure mode change from flexure to shear.