Material Characterization of FRP Pre-Cured Laminates Used in theMechanically Fastened FRPStrengthening of RC Structures

Abstract

Synopsis: The Mechanically Fastened-FRP (MF-FRP) strengthening system consists of pre-cured FRP laminates having high longitudinal bearing strength attached to the concrete surface using closely spaced steel fasteners in the form of nails or concrete wedge anchors. The connection depends on several parameters such as, the intrinsic laminates properties (tensile and bearing strength), diameter and effective embedment length of the fasteners, clamping force, presence and type of washer, presence and type of filler in the gaps between the FRP material, the fastener and accessories, and the concrete. This paper focuses on the material characterization of pultruded precured laminate which was used as MF-FRP strengthening to retrofit and rehabilitate offsystem bridges in Missouri, USA. Tensile tests, in the longitudinal and transverse direction of the laminate, were performed on full section and open hole coupons in order to characterize the material. Bearing tests, in the longitudinal and transverse direction of the laminate, were performed to determine the capacity of the unrestrained fastener-FRP-concrete connection.