ACI STRUCTURAL JOURNAL, cilt.111, sa.2, ss.267-277, 2014 (SCI-Expanded)
Reported are the results of experiments on 10 rectangular reinforced concrete (RC) beams with and without multiple web openings. The effects of opening geometry, the-use of longitudinal stirrups in the posts between the openings, the use of diagonal reinforcement around openings, and the longitudinal reinforcement ratio on the flexural behavior of RC beams with openings were investigated. The stirrups in the posts were shown to have a significant contribution to the ductility of an RC beam with openings if no diagonal reinforcement is used. For the same reinforcement details, RC beams with circular openings were found to have higher load capacities and ductilities than beams with rectangular openings. The experiments indicated that the posts between the openings need to be prevented from undergoing shear failure to avoid Vierendeel truss action and allow a beam to develop its ductility and bending capacity.