Experimental and analytical investigations of bonding ultrahigh strength fibre concrete panels on reinforced concrete structures with low concrete strength

A large number of aging reinforced concrete (RC) bridges have become huge potential safety hazards. Due to poor design and/or construction, some of these old RC bridges do not even meet basic safety requirements such as shear capacity. This paper presents a new shear strengthening technique of bonding ultrahigh strength fibre reinforced concrete (UFC) panels onto the ends of girders of aging RC bridges. This technique has many attractive characteristics, such as outstanding durability, workability, efficiency and reliability. To investigate the effect UFC strengthening has on the shear resisting mechanism and bond–slip properties of rebars embedded in RC beams, experiments and finite-element analyses were conducted. The experimental results show that both the shear resisting capacity and the bond–slip properties of rebars improved when UFC panels were applied. Analytical results from the modified bond–slip model show good agreement with the experimental results in terms of load–deflection and crack patterns.