Experimental investigation of dimensional ratio effects on shear capacity of high-performance cementitious composites deep beams

Abstract

Deep beams are generally used as main load-bearing beams or pile caps which are very common in high rise buildings. The span to height ratio of beams is an essential parameter in their flexural and shear behaviors . The usage of composite concretes conjuncture with fibers enhances the deep beams to overcome the relative brittleness and fragility of concrete and its low energy absorption. In this paper, the experimental research on eight deep reinforced concrete beams cast and replaced with high-performance cementitious composites was carried out. Two group specimens with 2% steel fiber and without fiber, the same height, and similar reinforcement details, and also different span to height ratios from 0.75 to 2 were considered and tested with the three-point flexural method. The experimental ultimate shear strength was compared with the predicted value in different codes. The test results indicated that the load-bearing capacity of deep-beam specimens was increased up to 84.8% with the same dimension when replacing conventional concrete with cementitious composites containing 2% of steel fiber. • New relations suggested to determine the ultimate capacity of deep beams made from cementitious concrete with fiber. • An experimental study was conducted regarding the shear behavior of deep beams using this material, might be a sort of innovation. • Extra work on structural aspects and applying this material and the behavior of deep beams made from this material are of high importance.