Investigation of the behavior of FRP reinforced beams containing engineered cementitious composite

Concrete exhibits brittle behaviour with increasing compressive strength, so different types of fibers are used in the construction of reinforced concrete members to improve this disadvantage and to obtain ductile behaviour. Engineered cementitious composite (ECC) is a very useful material for reinforced concrete structures due to its high tensile ductility and micro crack wideness features. Besides, Fiber Reinforced Polymers (FRP) are good alternative materials to steel reinforcements due to its features such as, high corrosion resistance, high tensile strength, lightweight and high resistance to the chemical reactions. Brittle behaviour of FRP reinforcement, decreases the ductility of FRP reinforced structures. Recently, ECC material has been used in the structures instead of ordinary Portland cement concrete to increase ductility of members and to maintain high strength property of FRP reinforcement. In the presented thesis, FRP reinforced beams having ECC and concrete material were prepared. The beams were tested under four-point static load to determine the structural behaviour. In the experimental study, load-deflection curves of beams and load-strain diagrams of FRP reinforcements have been obtained. In the tests, good degree of deflection capacity was seen for the beams. An increase was observed in load carrying capacity and midspan deflection of the beams with increasing ECC deepness. In addition, it was seen that more strain capacity obtained with increasing ECC deepness. In the study, a theoretical method was developed considering nonlinear behaviour of the concrete and ECC material to obtain the ultimate load capacity and load-deflection curves of FRP reinforced beams having concrete and ECC material. The deflections of the tested beams were determined on the basis of ACI 440.1R-15 Code and Sine Curve Method. The obtained theoretical load-deflection curves have been compared with experimental curves. In the study, good degree of agreement has been attained between the experimental and theoretical results.