Effect of thermal aging on the mechanical performance of timber-timber single-lap adhesive joints

Timber is a natural material traditionally used in the building industry. In the last decades, developments in scientific research have made timber a high-tech building material. In the field of timber engineering, recent developments concerned advances in the study of adhesive joints and their applications in the field of structures. The growing interest in adhesive joints in timber structures is due to the advantages offered by adhesive tech-nology over traditional mechanical joining techniques. In this paper, the effect of exposure of adhesive joints between timber adherends to high values of temperature and relative humidity is investigated. In particular, two different two-component (2K) epoxy adhesives (EPX1, EPX2) and one polyurethane (PU) in single-lap adhesive joints between mahogany and pine adherends have been used and compared. This research work investigates the possibility of realising new joints between timber adherends in innovative building components (e.g. windows and curtain walls). The results obtained from the experimental campaign showed that PU adhesive has lower mechanical performance than epoxy adhesives, regardless of the aging condition. On the other hand, the epoxy adhesives tested showed high performance and different mechanical behavior after artificial aging.