Behavior of concrete beams with hybrid reinforcement under flexure

Abstract

In a developing country like India, the demand for infrastructural facilities such as highways, flyovers, bridges, and residential housing systems has been increasing rapidly. Construction of these infrastructures requires concrete as a primary construction material which cannot be used for practical applications without using reinforcing elements such as steel. However, the durability of the concrete structures is significantly influenced by the corrosion behavior of reinforcing steel. Therefore, corrosion of steel largely determines the life span of reinforced concrete structures, especially in marine environments. For example, the American Society of Civil Engineers (ASCE) have stated that approximately 56,007 bridges in the United States are classified as structurally deficient primarily due to corrosion of reinforcement. The cost estimated to rehabilitate the structurally deficient bridges was nearly 5$ billion per year (Glass and Buenfield 2000). Also, repair and rehabilitation of concrete structures results in inconvenience to the public. Thus, corrosion of steel reinforcement causes both direct and indirect economic loss to a country. Hybrid reinforcement consisting of a steel core with Fiber-Reinforced Polymer (FRP) wrapping is a recognized alternative to conventional steel reinforcing bars for concrete structures. Different types of fibers such as glass fibers, carbon fibers, and aramid fibers are used in FRP wrapping. The type of fibers and the number of wrapping and hence fiber content influence the property of the hybrid reinforcement. newlineA review of literature revealed the availability of research studies investigating the property of hybrid rebars and the behavior of concrete structural members reinforced in the tension zone with FRP bars or combination of FRP bars and steel rebars or hybrid rebars with steel core and FRP wrapping. Further, it indicated a number of variables considered in the reported research studies based on type of fibers used for wrapping, fiber content, diameter of the steel cor