Four-point bending tests on laminated glass beams reinforced with FRP bars adhesively bonded to the glass

The paper presents results of an experimental campaign on reinforced glass beams, that represent a safe solution for the use of glass as a structural material. A new kind of FRP reinforced glass beams, formed by three-layer laminated float glass plies and two FRP bars, is proposed. One bar is installed along the upper edge of the beam and the other along the lower edge; both bars are housed inside a “U” shape channel, that allows to bond bars on three sides. Common structural resins are utilized as adhesives, after assessing their bond strength to glass through adhesion tests and pull-out tests. The tensile FRP bar can sustain normal stresses after the glass fracture, like steel rebars in reinforced concrete beams after concrete cracking. The structural response of proposed beams was investigated through four-point bending tests under room temperature and short-term loads. Both smooth and helical wrapped (HW) bars were used as reinforcing bars, and two different types of resins were utilized to bond bars to the glass. Main experimental results are discussed, together with limitations in the application and possible improvements.