Carbon Fiber Reinforced polymer (CFRP) bars are weak in yielding property which results in sudden failure of structure at failure load. Inclusion of non-pretensioned steel reinforcement in the tension side of CFRP based prestressed concrete beam will balance the yielding requirements of member and it will show the definite crack failure pattern before failure. Experimental investigation has been carried out to study the deflection behavior of partially prestressed beam. Experimental works includes four beam specimens stressed by varying degree of prestressing. The Partial Prestressing Ratio (PPR) of specimen is considered for experimental works in the range of 0.6 to 0.8. A new deflection model is recommended in the present study considering the strain contribution of CFRP bar and steel reinforcement for the fully bonded member. New deflection model converges to experimental results with the error of less than 5% .
Fiber-reinforced polymer (FRP) composites are preferred as prestressing tendons in concrete structures due to its high-strength, lightweight and non-corrosive property. FRP based prestressed concrete member exhibits different crack behavior than steel based prestressed concrete member due to its less stiffness and non-ductile property. An experimental investigation was carried out to study the cracking behaviour of concrete member using Carbon fiber reinforced polymer (CFRP) bars as prestressing material. Experimental works includes four numbers of prestressed concrete specimens by varying degree of prestressing of 35 to 70%. The characteristics of crack spacing, crack propagation and crack widths of member were presented. Experimental results were compared with various researchers’ recommendation and proposed a new crack width model by modifying the Frosch crack width model.
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 deflection values as per ACI 2011, is about 10 to 20% has reduced to less than 5% in the proposed method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.