Flexural behavior of hybrid glass beams with rectangular cross-sections

An experimental investigation regarding the flexural and the shear behavior of glass beams with length 900, 1300, 1700 mm and rectangular cross-section is presented and discussed. Rectangular cross-sections were obtained by assembling three float glass panels of depth 200 mm and thickness 6 mm through an acrylic adhesive with an effective depth of 19.52 mm (6 + 0.76 + 6 + 0.76 + 6 mm). Some specimens were also reinforced internally with steel plates of thickness 6 mm and depth 25 mm and thickness 6 mm and plates of thickness 6 mm and depth 50 mm placed at the bottom portion of the beams for the entire length of the beams themselves. Three specimens for each investigated series were tested in flexure focusing on the flexural and shear response through the determination of the load-deflection curves, and the crack patterns at rupture. The shear span to depth ratios a/d were 2, 3 and 4, respectively. In the paper an analytical model is also presented for a preliminary design of composite glass beams able to predict the ultimate load including limit states due to glass cracking, flexural failure with glass crushing or plates yielding, shear compression and diagonal tension failure. This model can be useful to perform simulations in order to investigate the structural resistance of hybrid glass beams to the varying of the geometrical characteristics of beam, of the reinforcement area and on the type of reinforcements.