Redundancy of reinforced glass beams : temperature, moisture and time dependent behaviour of the adhesive bond

The most important aspect of the reinforced glass beam concept, which provides ductility and redundancy for structural glass beams, is the adhesive bond between glass and reinforcement. To guarantee structural safety, this adhesive bond has to service under all conditions. The effects of elevated temperature, moisture exposure and load duration on the adhesive bond, have separately been investigated through three series of bending tests on 1.5 m reinforced glass beam specimens. A first series has been tested at 60 C; a second series has been tested after 8 weeks of salt-water-spraying; and a third series has been loaded until initial failure whereupon it has been left statically loaded for at least 72 hours. The results show that the reinforced glass beam concept is a redundant system which shows, dependent on the applied adhesive, a significant residual strength even at extreme temperature and moisture conditions, and for a significant period of time