Use of Carbon Fibre to Evaluate Mechanical Properties of Concrete

Abstract

Concrete is the large used construction material. It is difficult to find out another material of construction, which is as versatile as concrete. Concrete is seemingly simple but actually complex material. Crack formation in reinforced concrete structures will takes place due to low tensile strength of concrete. Wider cracks may not only destroy the aesthetics of structure, but also expose steel reinforcement to the environment leading to corrosion. Cracking in reinforced concrete members also causes a significant increase in deflection. This is a result of the reduction in bending stiffness at cracked section. Reinforced concrete structures with high strength deformed bars and designed using limit state method was found to have larger crack widths. Bending is one of the reasons for flexural cracks. These cracks appear in the tension face & extend vertically in a small region over interior supports & in mid span regions of continuous beams. Cracking usually near elastic neutral axis, because of diagonal tension caused due to dominant shear force. One viewpoint is that cracks reduce the service life of structures. The tensile strength of concrete is about 10 percent of the compressive strength, but in the design of reinforced concrete structural elements, this strength is neglected. as we know Steel reinforcement is provided to carry the tensile stresses in a member due to applied loads. It is anticipating that cracks will develop in a reinforced concrete member under service loads. we know that in tension zone, the steel reinforcement is engaged primarily when a crack occurs, and design of reinforced concrete structures is carried out based on the fact that significant portions of the structure are cracked.