| Composite materials are commonly used worldwide for the strengthening of civil structures. In Japan, FRP strengthening methods have been intensively used for the seismic retrofit of bridge columns after Kobe earthquake (Saito 2002). In France, such methods are mainly applied to the rehabilitation or upgrading of damaged structures (Luyckx 1999). Nevertheless, the durability of the adhesive bond at the concrete/composite interface is still a matter of investigation (Grace 1995, Karbhari 2007). In this paper, the first results of 2 ongoing studies conducted by the French and Japanese Public Works Research Institutes (LCPC and PWRI) are presented. On the French side, CFRP strengthened concrete slabs were exposed to accelerated ageing in saturated humidity. Time evolution of the adhesive bond strength was monitored by either pull-off or shear loading tests. On the Japanese side, similar specimens have been exposed to outdoor ageing for 14 years, and the residual bond strength was evaluated by pull-off or peeling tests. These data offer a unique opportunity to compare the effects of laboratory and environmental ageing on the concrete/FRP interface. |
