Deflection of a Concrete T-beam with Prestressed and Non-prestressed Fiber Reinforcement Polymers at Elevated Temperatures

Abstract

Prestressed concrete members have gained popularity as an efficient and effective way of designing a structural member with the best engineering and material properties. The method of prestressing a structural concrete member has the capability of controlling increased service loads with less depth over longer spans. However, deflections from over-loading or loading over time give a disadvantage to the common steel reinforced concrete members by the effect of corrosion as the structural concrete develop cracks. To prevent corrosion of a structural concrete member, exchanging of steel reinforcement with Fiber Reinforcing Polymers (FRP) has sparked engineering interest in recent years. Both prestressed and non-prestressed FRP reinforcement can reduce tension in concrete. However, the performance of such structural members under elevated temperatures is currently unknown. The knowledge and application of this may lead to a cost effective, and practical consideration in fire safety design. In this article, an analytical model is developed using flexural rigidity of a concrete T-beam with both prestressed and non-prestressed FRP reinforcement to study the deflection behavior at practical elevated temperatures. The model is compared with the finite element model (FEM) of a T-beam with both prestressed and non-prestressed reinforcement subjected to practical elevated temperatures. In addition, comparison is also made with an indirect reference to the real behavior of the material. The results of the analytical model correlated reasonably with the FEM and the real behavior, and were within the accepted range of the American Concrete Institute (ACI) specifications.