ABSTRACT
The potential of using CFRP sheet anchorage to prevent or delay the detachment of CFRP strips, bonded to the tension side of under reinforced concrete beams, was experimentally evaluated. CFRP strips (50 × 800 mm) were bonded to sixteen beams (100×150×1400 mm) before fourteen of which were anchored by either segmented or continuous CFRP sheets, attached above and beyond the strips and extend laterally to the beams’ soffits for (50–100) mm. Four beams were specified as strengthened without anchorage and control. The mechanical behavior of the beams was evaluated under four-point loading, before the data collected were analyzed for load-deflection, and bond stress versus slippage relationships and their characteristics. Crack formation and failure mode were monitored and characterized, as well. Anchoring CFRP strips at their ends by 300-mm-long CFRP sheet segments, with lateral extension, had improved the structural without degrading the ductility or toughness, hence can be considered as the most efficient and economic anchorage technique. Prior to flexural failure of the strengthened beams, the CFRP composites showed free-end debonding and/or concrete cover rip-off. A finite element model (FEM) was proposed, verified by experimentally obtained data, before used to expand predictions of mechanical behavior and modes of failure to promising anchorage cases that were not studied experimentally.
