Effect of temperature and relative humidity on the shear performance of double-lap adhesive joints between steel and glass adherends

Abstract The use of large glass areas is a hallmark of modern architecture, and glass is also used as a structural element in many applications. Recent developments in the field of structural adhesives have led to the development of bonding solutions between steel and glass adherends that meet the structural and aesthetic requirements for high performance buildings. Indeed, the use of adhesive bonding technology allows for uniform stress distribution, enabling ductile hybrid joints to be achieved by combining materials with different mechanical properties. However, the main weakness of this assembly system is the influence of high values of temperature and humidity values on the mechanical behaviour of bonded joints. This paper reports the experimental results obtained on double-lap adhesive joints between steel and float glass adherends. In particular, the results obtained after curing under laboratory conditions are compared with those obtained after exposure to high temperature (40 °C) and relative humidity (100% RH). The performances obtained with two two-component epoxy adhesives (EPX1, EPX2), one polyurethane adhesive (PU) and one silicone adhesive (SIL) are compared and discussed. The results of the experimental campaigns show that the epoxy adhesives achieve the best mechanical performance in relation to the studied application, while the SIL adhesive exhibits the worst mechanical performance in each case.