effect of size and location of square web openings on the entire behavior of reinforced concrete deep beams

this paper presents an experimental and numerical study which was carried out to examine the influence of the size and the layout of the web openings on the load carrying capacity and the serviceability of reinforced concrete deep beams. five full-scale simply supported reinforced concrete deep beams with two large web openings created in shear regions were tested up to failure. the shear span to overall depth ratio was (1.1). square openings were located symmetrically relative to the midspan section either at the midpoint or at the interior boundaries of the shear span. two different side dimensions for the square openings were considered, mainly, (200) mm and (230) mm. the strength results proved that the shear capacity of the deep beam is governed by the size and location of web openings. the experimental results indicated that the reduction of the shear capacity may reach (66%). abaqus finite element software program was used for simulation and analysis. numerical analyses provided un-conservative estimates for deep beam load carrying capacity in the range between (5-21%). however, the maximum scatter of the finite element method predictions for first diagonal and first flexural cracking loads was not exceeding (17%). also, at service load the numerical of midspan deflection was greater than the experimental values by (9-18%).