Flexural behavior of RC beams with regular square or circular web openings

•RC beams with multiple circular or square web openings were tested.•Diagonal reinforcement around openings prevented premature failure of the beams.•Sharp corners of square openings cause higher reductions in ultimate loads.•Presence of multiple openings in the span has a positive effect on beam behavior.•Stirrups in chords and full-depth stirrups next to openings prevent shear failure. This paper presents a study aimed at investigating the influence of multiple web openings along the length of an RC beam on its flexural behavior. A total of nine rectangular beams were tested. Diagonal reinforcement around openings effectively prevented premature failure of some specimens due to Vierendeel action, the expected failure mode according to bending moment-axial force interaction diagrams. Longitudinal rebars and full-depth stirrups adjacent to openings and short stirrups in the chords prevented beam-type and frame-type shear failures. The length of the plastic failure mechanism increased in the presence of multiple openings compared to beams with a single opening.