The Control of Flexural Cracks in the Design of Reinforced Concrete Beams for Kabul City s Exposure Condition

Abstract

For a concrete structure to be serviceable crack width must be controlled and must not exceed the limited values for a specific exposure condition. Cracking in the concrete is the a most challenging issue for engineers since it reduces the overall strength of the structure, damages the aesthetics of the concrete, and causes corrosion in steel bars. The current study addresses the effects of flexural cracks on the serviceability of concrete structures and the control of cracks in the design of reinforced concrete beams. The study also aims to outline the importance of the control of flexural cracks, their major consequences, and the magnitude of cracking in reinforced concrete beams. A reinforced concrete beam model is designed and described for predicting the flexural cracks through numerical analysis and remarking its parameters, such as steel bars diameters, concrete covers, and steel bars arrangements that affect the size of flexural cracks in the tensile zone of concrete members. A total of 14 specimens are used to measure the range of crack widths for various scenarios based on which the significant variables affecting crack width are identified. The study concludes that the consideration for crack control in the design of reinforced concrete beams is essential. Hence, structural engineers should take extreme measures to ensure safety and serviceability when designing the structure by taking the crack-limit state into account. Keywords: Reinforced Concrete Beams, Flexural Cracks, Serviceability, Steel Bars’ Arrangement, Concrete Cover.