Failure mechanisms and residual capacity of annealed glass/SGP laminated beams at room temperature

In construction industry, laminated glass is more and more used for transparent load-bearing building components. It is known that the residual load-carrying capacity after glass breakage of glass/PVB (polyvinyl butyral) laminates is relatively poor, mainly due to the limited stiffness and strength of PVB. For that reason, the failure behaviour of laminates composed with a stiffer and stronger interlayer material, called SentryGlas® Plus (SGP), was investigated experimentally. Consequently, 1100 mm long test samples composed of two annealed float glass layers and one SGP interlayer were subjected to destructive in-plane four-points bending tests at room temperature. Subsequently, different stages were distinguished during the failure process, corresponding to a different number of broken glass layers. In spite of the relatively good interlayer material properties and in contradiction to what was expected, the observed post-failure safety was poor. However, the failure mechanisms observed were significantly different from those of glass/PVB beams: due to a lack of local delamination near the glass fracture zone, tear of the SGP interlayer occurred without preceding large visual interlayer elongations.