Static and fatigue bond behaviour of GFRP bars and concrete

The experimental investigation is intended to study the influence of some parameters on the quasi-static and the fatigue behaviour of the bond between glass fibre reinforced plastic (GFRP) rebars and concrete. This is an important aspect in FRP reinforced concrete structural elements and of relevant importance in thin reinforced concrete panels extensively adopted as façade or pavements. The pull-out set-up with eccentrically positioned GFRP ComBAR® bar was adopted to measure the effect of two parameters on the bond mechanical features: thickness of the concrete cover and concrete mechanical properties. For cycling tests, another parameter, the maximum load in the cycle, was introduced to estimate the fatigue life under different load levels. Quasi-static tests showed that concrete compressive strength influence on bond properties is much more pronounced than that of the concrete cover. Cyclic tests at highest load level revealed that higher concrete quality attained longer fatigue life.