Experimental INVESTIGATION on timber-glass double-lap adhesive joints

Abstract Recent advances in research in the field of structural adhesives have led to the development of new hybrid multi-material structures. In this type of application, different components are combined to create high performance structural elements characterized by low weight and ease of installation. In this experimental study, a series of shear tests were conducted on double-lap adhesive joints, in which float glass was adhesively bonded with mahogany and pine adherends. In particular, the effects resulting from the use of two types of selected epoxy adhesives and different surface treatment methods for timber adherends (i.e. dipping and varnishing treatments) were analysed. This experimental campaign aims to verify the compatibility of the adhesive joint between the mentioned adherends, with particular reference to its application in the field of civil engineering. The results obtained show that the epoxy EPX1 adhesive provides the best performance in terms of stiffness and strength for the substrate combination with untreated mahogany and float glass. In fact, this configuration leads to the stiffest type of joint while achieving high load values. EPX2 adhesive achieves higher ultimate strength values in all other combinations of adhesives analysed and exhibits greater ductility. The results demonstrate an excellent compatibility between the materials considered and the effectiveness of the adhesive joint for the intended applications.