Deflection Behavior of Prestressed Concrete Beam using Fiber Reinforced Polymer (FRP) Tendon

Abstract

The application of prestressing steel is restricted in highly corrosive environment area. The behavior of structure changes due to corrosion of prestressing steel, which leads to reduction in strength and it may cause sudden failure. There are many research recommendations to resist corrosion of steel, however the durability of structure shall not be ensured during service life of structure. Fiber Reinforced Polymer (FRP) Tendon is considered as an alternate material due to its corrosive resistance property and high strength. An experimental and numerical analysis carried out to study the deflection behavior of FRP tendon prestressed beam and recommended design guidelines. There are four beam specimens casted and tested in laboratory and 51 experimental results collected from research article to carry out numerical study. The ACI, 2011 [1] recommended generalized deflection calculation for beam by softening the effective moment of inertia curve and also introduced the effect of shift of neutral axis once the member exceeds cracking stress of concrete. Based on experimental and numerical analysis study it is concluded that, the deflection behavior of FRP tendon beam depends on deformability of material, degree of prestressing and bond strength. Design chart proposed for calculation of effective moment of inertia and effective neutral axis distance with respect to deformability index. The error percentage of deflec-tion values as per ACI 2011, is about 10 to 20% has reduced to less than 5% in the proposed method.