Passage of the pipes and ducts for the air-conditioning, heating, sewage, and water supply systems, and for the telephone, electric- ity, and internet cables through transverse openings in floor beams enables the engineers with a more efficient building design by uti- lizing the dead space above the beam soffit. The utilization of this dead space reduces the heights of the bearing and nonbearing members and therefore the overall height of the building. Conse- quently, the loads on the foundation and on the load-carrying structural members are reduced and a more economical design achieved. Nevertheless, the presence of web openings in an RC beam reduces its load capacity and increases its service-load deflections and crack widths. It is desirable to provide an RC beam with openings with the load capacity and stiffness of a solid beam with the same dimensions, by proper reinforcement detailing, which will also counteract the negative influence of the stress con- centrations around openings and prevent premature failure of the beam due to Vierendeel truss action.
The studies in the literature mostly focused on developing de- sign guidelines for new build RC beams with openings, i.e. RC beams with openings in the original design and construction of the beam, to provide these beams with sufficient ductility and load