Takahiro Matsui

Composite Behaviour of a Hybrid FRP Bridge Girder and Concrete Deck

This paper involves experimental investigation onto the composite behaviour of a hybrid FRP bridge girder with an overlying concrete deck. Two types of shear connections were investigated: epoxy resin adhesives alone and epoxy resin combined with steel u-bolts. The results showed that the steel u-bolts combined with epoxy resin provided a more effective connection; hence a full-size specimen was prepared based on this result. Four-point bending test was carried out to determine the behaviour of a full-scale composite hybrid FRP girder and concrete deck. The composite action resulted to a higher stiffness and strength with the hybrid FRP girder exhibiting higher tensile strain before final failure. There was a significant decrease in the compressive strain in the top flange of the FRP girder thereby preventing the sudden failure of the beam. The composite beam failed due to crushing of the concrete followed by shear failure in the top flange and web of the FRP girder.

Trial Design of Cable-Stayed Bridges Using Hybrid Composite Girders and Applicability to Free Passage Over Railway

A pultruted hybrid composite girder is being developed consisting of carbon and glass fibers. The innovative feature is the optimum use of CFRP and GFRP in the flanges to maximize structural performance while reducing the overall cost by using glass fibers in the web section. In this paper, the cable-stayed bridges were trially designed using the developed hybrid composite girders. In order to utilize the lightweight of FRP, the construction site was selected to the free passage over the busy railway as a case study. The cable-stayed bridges were two continuous-span bridges with the span lengths of 5.5 m and 24.0 m. As a result, the feasibility of the proposed structures and the reduction of total cost were confirmed.

Damage sensing and mechanical characteristics of CFRP strengthened steel plate

In recent years, a large number of structures that were built during the period of high economic growth in Japan is beginning to show signs of aging. For example, the structural performance of steel structures has degraded due to corrosion. One measure that has been proposed and studied to address this issue is the adhesive bonding method, which can be used to repair and reinforce these structures. However, this method produces brittle fracture in the adhesive layer and is difficult to maintain after bonding. To solve the problem faced by this method, a clarification of the mechanical properties inside the adhesive is necessary. Then this background, a fiber Bragg grating (FBG) sensor has been used in this study. This sensor can be embedded within the building material that needs repairing and reinforcing because an FBG sensor is extremely small. Eventually based on this, a three-point bending test of a carbon fiber reinforced plastic (CFRP) strengthened steel plate that was embedded with an FBG sensor wa...