Shear Strength of Deep Beams

Abstract

Results of tests on 52 deep reinforced concrete beams under two equal symmetrically placed point loads are reported. The investigation's objectives were to study the effect of vertical and horizontal web reinforcement and shear span-to-effective depth ratio on inclined cracking shear, ultimate shear strength, midspan deflection, tension reinforcement strain, and crack width. Test results indicated that web reinforcement produces no effect on formation of inclined cracks and seems to moderately affect ultimate shear strength. Addition of vertical web reinforcement (e, = 0. I 8 to I .25 percent) improves ultimate shear strength of deep beams. However, addition of horizontal web reinforcement (Q,h = 0.23 to 0.91 percent) had little or no influence on ultimate shear strength. Considerable increase in load-carrying capacity was observed with increasing concrete strength and decreasing shear spanto-effective depth ratio.