Interfacial behaviour between Mechanically Fastened FRP laminates and concrete substrate: test results and modelling (original) (raw)
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Interfacial Behavior between Mechanically Fastened FRP Laminates and Concrete Substrate
Advances in FRP Composites in Civil Engineering, 2011
This study addresses the interfacial behavior between Mechanically Fastened FRP (MF-FRP) laminates and concrete substrate. For this purpose, a simplified numerical model is formulated with the aim of developing a suitable bearing stress-slip relationship to model the mechanical behavior of the FRP/concrete interface. The proposed relationship is significantly different from another proposal found in the literature as it was calibrated using experimental results from tests on MF-FRP connections realized with multiple fasteners.
Experimental investigation of the mechanical connection between FRP laminates and concrete
Composites Part B: Engineering, 2013
This paper presents the results of an experimental campaign aimed at investigating the interfacial behavior of Fiber Reinforced Polymer (FRP) laminates Mechanically Fastened (MF) to concrete members. The experimental program includes 34 direct shear tests (DSTs) performed on FRP laminates fastened to concrete prisms through either single or multiple screwed anchors arranged according to different layouts. In 17 tests a steel washer was interposed between the head of each fastener and the outer side of the laminate; in the remaining ones, instead, no washer was used. The performed tests allowed to evaluate the behavior of the MF-FRP connections mainly in terms of loadcarrying capacity, FRP strain distribution and damage mechanism; the influence on the experimental response of both fastener configuration and washer presence was also investigated. Results of tests on specimens fastened by using a single screw were used for calibrating a possible forcedisplacement law to describe the interaction between MF-FRP laminate and concrete substrate. Finally, simplified FEM models were implemented and verified for better simulating the experimental results and estimating the strain and stress distributions within the laminate.
2012
This paper presents a three-dimensional (3-D) meso-scale finite element (FE) model for near-surface mounted (NSM) FRP strip-to-concrete bonded joints established using the general-purpose FE software package MSC.MARC. In the FE model, elements of the order of 1 mm in size are employed. The concrete is simulated using the orthogonal fixed smeared crack model while the FRP and the adhesive are treated as linear brittle-cracking materials. The FE model is calibrated and verified using results of well-documented bonded joint tests. Using the verified FE model, the failure process of NSM FRP strip-to-concrete bonded joints is carefully studied; furthermore, the local bond stress distributions and the bond-slip relationships are extracted and analyzed. This 3-D meso-scale FE model offers a powerful tool for deployment in further investigations to establish bond-slip models and bond strength models for NSM FRP strip-to-concrete bonded interfaces. While the present study is focused on NSM FRP strips, the proposed modeling approach is generally applicable to NSM FRP bars of other cross-sectional shapes.
Mechanics of fibre-reinforced polymer - concrete interfaces
Canadian Journal of Civil Engineering, 2007
A finite element model is developed for analyzing the interfacial behaviour for fibre-reinforced polymer (FRP) laminates externally bonded to concrete prisms and subjected to direct shear. The element sizes of the FRP, adhesive, and concrete at the interface were chosen to be very small (0.25-0.5 mm) so that the debonding behaviour could be properly captured. The behaviour at the interface between the FRP composite and the concrete is modelled using truss elements connecting the FRP laminate to the concrete block. The truss elements incorporate a nonlinear bond stress-slip relationship controlled by several parameters related to the characteristics of the FRP composite, adhesive, and concrete. Results are given in terms of the load capacity of the joint and the stress and strain distributions in the FRP, at the interface, and in the concrete. In addition, the transfer lengths, as well as the force transfer between the FRP laminate and the concrete block, are investigated. Comparisons between the finite element results and available experimental data are presented.