Strengthening of reinforced concrete beams with externally attached titanium rods

This paper offers the results of an experimental investigation aimed at assessing the structural behavior of Reinforced Concrete (RC) beams retrofitted with externally attached titanium rods. Existing RC structures are often susceptible to freeze-thaw damage since the concrete was not air entrained in the past, and acidic substances in the rain, if exposed, and the surrounding soil and water can cause disintegration of the concrete surface due to a reaction between the acid and the hydrated cement. These concrete structures often need to be reinforced, but interventions are expensive, invasive and difficult to carry out. In this research concrete beams were reinforced with high strength titanium rods in order to add more tensile resistant material, especially when old steel bars are insufficient or degraded, and resist internal tension forces within the cross section. A total of 8 full-size concrete beams were tested in this experimental programme at the laboratory, by conducting bending tests aimed at studying the flexural structural response. Different titanium retrofit solutions were studied and used to reinforce the beams. It was found that the bending-capacity of the concrete beams reinforced with the titanium rods greatly increased over that of the control unreinforced specimens. The proposed reinforced method was able to provide some significant additional resisting capacity to the beams in a more effective way than the traditional methods of composite materials.