Experimental evaluation of the common defects in the execution of reinforced concrete beams under flexural loading

Design of any structural element should realize the appropriate load capacity to serve the purpose of construction beside the esthetical function. Therefore, the accompanied symptoms of distress during loading conditions like cracking, deflections, and strain distribution all over the section will definitely influence the performance of these elements and their durability in sequence. Flexural moment is the most dominant straining action in many of the reinforced concrete elements such as beams, slabs, and frames. Thus, in this investigation an experimental program was carried out on deficient concrete beams which were somewhat designated to simulate the possible defects in the field, like errors in the arrangement of main steel, splices in different places (even at the maximum moment zone). Faults of improper workmanship were represented using a beam of honey-combed concrete and other of insufficient cover. On the other hand, a control beam was parallely cast for the purpose of comparison. Measurements like strains of concrete and steel, deflections and propagation of cracks were all observed and detected to evaluate to how any of these practice faults influence the behavior of beams. It was found that well-arranged distribution of reinforcement improves the ductile behavior of failure and reduces the corresponding deflections. Meanwhile, eccentricity of main steel creates a sort of non-uniform stress distribution over the section and accelerates approaching failure stage. In addition, the honey-combed structure undergoes more symptoms of distress and approaches failure faster without intermediate stage. Despite the fewer grids of cracks noticed, the honey-combed beam exhibits higher deflection values