Durability of FRP composite bridge decks construction and temperature effects

During the past several years, a relatively large body of research has been directed toward better understanding of behaviour of civil infrastructure employing Fibre-Reinforced Polymer (FRP) composites, and for development of design guidelines. Nevertheless, these studies have generally ignored or marginally evaluated the reaction of structural systems using FRP to the environment, most importantly temperature changes, and loads to which civil engineering structures are subjected. Using an extensive array of instruments and field as well as laboratory tests, the short-term and long-term performances of four types of FRP composite bridge decks were recently evaluated. The coefficient of thermal expansion and the level of temperature gradient were found to be higher than those of standard reinforced concrete decks. Lack of attention to detailing and thermal characteristics of individual components as well as the entire FRP deck system can lead into build up of large thermal gradients, which can result in unexpected deformations and damage. To ensure satisfactory performance, thermal behaviour and the resulting thermal stresses need to be incorporated into design and detailing of panel-girder connections, field joints, and face sheet-core connection in sandwich type panels. Based on the presented information, a number of recommendations for improved behaviour are made.