Bond behaviour between near surface mounted CFRP and concrete members using magnetized bond agent under different temperature degrees

Abstract

ABSTRACT In this investigation, the bond performance between CFRP and concrete in Near Surface Mounted (NSM) strengthening system using cementitious-based adhesive (CBA) was evaluated at different exposure temperatures. Two types of CBA were used (CBA-A and CBA-B) with and without magnetic water (MCBA-A and MCBA-B). Magnetic device with magnetic strength of 9000 Gauss was used to magnetise the water for 15 mins with a flow rate of 0.1 m3/hr. The bond efficiency was evaluated by performing single-lap shear tests for CFRP laminate embedded in concrete prisms as a near surface-mounted strengthening system. The bond between CFRP and concrete was tested under ambient and high temperatures. The heating regime involves the exposure of NSM CFRP/concrete samples to constant temperature (200°C) for 2 hrs, then the load was applied until failure. In comparison with control samples, an improvement of 40% in the load failure was achieved for specimens strengthened with CFRP using magnetised water in CBA. Within the MCBA samples, higher failure load was conducted for MCBA-B samples when compared with samples of MCBA-A since the latter contain primer in its compositions in which its properties deteriorate by high temperature. All tested samples showed similar failure pattern, which is slippage of CFRP.