Ambient temperature performance of cementitious matrices for fire-safe NSM FRP strengthening of concrete structures

摘要

The near surface mounted (NSM) fiber reinforced polymer (FRP) strengthening technique is a demonstrated, attractive and efficient alternative to externally bonded reinforcement (EBR) strengthening systems. NSM strengthening can be used to enhance the stiffness and the strength of deficient reinforced concrete members, with high utilisation of the FRP's mechanical properties (at ambient temperature) when epoxy is used as bonding agent. However, owing to epoxy adhesives' sensitivity to elevated temperature exposure, recent research has focused on the use of cementitious adhesives, which are less sensitive to elevated temperature, in NSM FRP applications. This paper presents results from 22 bond pull-out tests at ambient temperature on concrete prisms with an embedded carbon FRP bar NSM strengthening system. Different bonding agents (i.e. epoxy resin or cementitious grout), positions of the bar in the groove (i.e. in the centre or at the top of the groove), bar surface treatments (smooth and ribbed) and bond length (300 and 400 mm) are investigated. (C) 2018 Elsevier Ltd. All rights reserved.