Tests on RC continuous beams with openings

Abstract

An experimental investigation is carried out on eight reinforced-concrete continuous beams, each containing a large transverse opening. The beams are rectangular in cross section and all contain the same amount and arrangement of longitudinal reinforcement. The number of spans, the size of opening, and its location along the span are considered as major variables. Detailed results of these tests are presented and discussed in this paper. Test results indicate four distinctly different stages of behavior in the load-deflection curve of a continuous beam. Final failure of the beam occurs by the formation of a mechanism, and the two opening ends represent the most vulnerable locations for the development of plastic hinges. Besides early cracking, the strength and stiffness of the beam decrease with an increase either in the length or depth of opening. Similarly, openings located in a high moment region produce larger deflections and result in early collapse of the beam.