Experimental and numerical studies on the shared activation anchoring of NSMR CFRP applied to RC beams

Abstract

A shared activation anchoring method used for carbon fiber reinforced polymer (CFRP) near surface mounted reinforcement (NSMR) strengthening is hypothesized to provide a mean to exploit the full material capacity and to tailor desired responses. To investigate strengthening efficiency, failure control as well as ductility levels, the developed strengthening system were mounted on reinforced concrete T-beams with a length of 6400 mm. Initial activation stresses of 50% (1100 MPa) and 70% (1540 MPa) were applied to an 8 mm CFRP rod by the anchor system. Then, in some beams finite element simulations were carried out for better understanding the obtained results with regard to the overall structural behaviour. Good correlations between the FE-simulation and tested responses were observed, where a high utilization of the CFRP material (up to 3300MPa) was reached. Installation of the activated system worked well, without premature failure. Additionally it was possible to control the failure development, where intermediate crack de-bonding was achieved when testing the beams with an activation level of approximately 50%, while fibre rupture occurred at the level of 70% activation, thus providing a CFRP strain of approximately 0,02.