Designers have to be very careful with respected to shear requirements in reinforced concrete (R.C.) elements due to their riskiness. Shear failure in R.C. beams is considered an undesirable failure mode because shear cracks develop without any warning. Swimmer bars are web reinforcement system alternatives for traditional shear reinforcement. Swimmer bars are small diagonal bars, with both ends bend over horizontally and tied with top and bottom reinforcement. The system of swimmer bars can be spliced, welded, or bolted and arranged in one or two rows. In this paper, an experimental study is carried out to investigate the shear behaviour of R.C beams which reinforced with swimmer bars as web reinforcement. Fifteen R.C beams are experimentally tested under monotonic load to study the effect of the number of swimming bars, type of splice, splice length and concrete strength on shear behaviour. The test results showed that using swimming bars as shear reinforcement increases the shear strength, stiffness, toughness as well as decreasing crack width, deflection values and the deformability of the tested beams.

The shear behaviour of deep beams considers as the main parameter of their load capacities. Therefore, the understanding of shear behaviour improvement by using inclined stirrups is essential to optimum design of web stirrups for deep beams. In this study, a numerical investigation is presented to describe the effect of inclined stirrups on the shear behaviour for reinforced concrete deep beams. This study was preceded by two steps as a part of verification and parametric study. In the first step, three beams were analysed with different arrangements of their stirrups. Two beams are reinforced with either vertical or inclined stirrups when there are no stirrups in the third beam. The numerically load-deflection curves, cracking patterns, and load-maximum crack opening curves were presented for all analysed beams. These numerical results were verified by the experimental study showing an excellent agreement between them. In second step, another 16 beams within 4 groups were analysed to show the parametric influence of using inclined stirrups. This parametric study presented the effect of main reinforcement ratio, shear span-to-depth ratio, space between stirrups, and bar cross-sectional area of stirrups on the deep beams reinforced with either vertical or inclined stirrups. The deep beam reinforced with inclined stirrups leads to a significant increase in the shear strength due to the contribution of these stirrups to restrict the opening of diagonal shear crack.