Effect of Moisture on the Interface of Timber and Externally Bonded Fibre Reinforced Polymers: A Review Paper

Abstract

Timber as a structural material has been in use since the medieval period. Even today, there are many residential houses being built with timber frame in Australia. Wooden wharfs and bridges are common examples of timber structures in coastal regions of Australia. Humidity in such coastal regions is often high causing an increase in moisture level in the timber structures. Besides, over-loading, rot and decay, termites and borers, etc. cause damage to timber and presence of moisture either aggravates this or favours such causes. Hence, there has been an increased demand for repair and rehabilitation of heritage and important timber structures. Strengthening wooden structures with fibre reinforced polymers (FRPs) is becoming popular in the construction industry. The objective of this paper is to demonstrate the effect of moisture on the durability of the timber-FRP interface. After reviewing previous studies in the durability of the timber-FRP composite, it has been found that prolonged moisture exposure leads to premature debonding in the timber-FRP interface. A graphical representation of the effect of moisture on bond failure has been established through this research work after investigating the previous work of scholars. This paper also highlights the significance of applying adhesion promoter in enhancing the performance of timber-FRP interface.