Corrosion Resistant Smart Composite Reinforcing Bars for Use in Concrete

摘要

In reinforced concrete (RC) structures, steel reinforcing bars (rebars) corrodewith time and thus reduce their life span. Composite rebards can be used in lieu of steel rebards to overcome this problem. The conventional composite rebards designed to take tensile force are composed of unidirectional fibers in a resin matrix, and are linearly elastic till failure; thus providing a brittle behavior. The problems of corrosion and brittle behavior can be solved by using a composite rebar which fails gradually under tension. The rebar consists of a hybrid composite system in conjunction with helical fibers. The hybrid system gives the rebar its initial stiffness and enables pseudo-yielding at lower strains. As the strain increases, the load is gradually transferred from the hybrid core to the helical fibers, which enables the rebar to undergo large elongations before failure. Embedded fiber optic sensors in the rebar can be used for health monitoring over a long period of time. The proof of concept and preliminary test results are described in this report.