Local bridging effect of fractured laminated glass with EVA based hybrid interlayers under weathering actions

Abstract

Local bridging ability between fragments including bridging force and adhesion concerns the post-fracture performance of laminated glass (LG). Weathering actions such as heat and lighting radiation can greatly damage bridging ability. The bridging behaviour of fractured LG under diverse weathering actions was examined in this work. Material specimens made of single EVA interlayer and hybrid EVA/PC interlayer, which were developed to provide better degradation resistance and long-term post-fracture performance for LG products, were manufactured. Uniaxial tensile tests on the interlayer specimens and through-crack tensile (TCT) tests on fractured LG specimens were performed after the specimens were exposed to the weathering actions including different temperatures, damp heat, and radiations from laboratory light source. Experimental observations, testing data such as bridging force–displacement relationship, normalized force and stress were analysed to discuss the effects of the weathering actions. Finally, the equivalent adhesion energy was determined to describe the failure of interfacial bridging. It is found that temperature rise to over 60 °C will greatly damage the bridging ability even for the specimens with hybrid interlayers, which also present limited bridging effects when temperature increases to nearly 100 °C. Damp heat and lighting treatment are found to have limited effects on the adhesion resistance of hybrid interlayer, although the former may facilitate interlayer rupture and the latter may result in greater degradation of adhesion energy.