Search results for " FRCM"
showing 10 items of 13 documents
Numerical modelling of the tensile behaviour of BFRCM strips
2019
This paper aims at investigating the tensile behaviour of basalt fibres on cementitious matrix for the strengthening of masonry structures. The use of Basalt Fibre Reinforced Cementitious Matrix (BFRCM) is favourably considered by the scientific community because it represents a natural composite material with high compatibility with stone and masonry substrate. The study is developed through the generation of Finite Element (FE) models capable of reproducing the tensile behaviour of BFRCM strips with different number of layers of grid. For the scope, the micro-modelling approach is adopted assuming different levels of detail for the simulation of the interface constitutive behaviour. Fibre…
Experimental results of RC columns strengthnened with Fiber Reinforced Cementitious Mortars
2012
The structural behaviour of reinforced concrete columns strengthened with a system made up of fibre nets embedded in an inorganic stabilized cementitious matrix was investigated. Specimens with circular and square cross-section were cast and subjected to monotonic uniaxial compression to investigate the efficiency of a Polypara-phenylene-benzo-bisthiazole (PBO) Fibre Reinforced Cementitious Mortars (FRCM) system in increasing both carrying capacity and ductility. The experimental results show that confinement with PBO fibre produced a noticeable increment in strength and ductility, though the low mechanical ratios of fibre considered were not always able to ensure hardening behaviour up to …
Stress-Strain Law for Confined Concrete with Hardening or Softening Behavior
2013
This paper provides a new general stress-strain law for concrete confined by steel, fiber reinforced polymer (FRP), or fiber reinforced cementitious matrix (FRCM), obtained by a suitable modification of the well-known Sargin’s curve for steel confined concrete. The proposed law is able to reproduce stress-strain curve of any shape, having both hardening or softening behavior, by using a single closed-form simple algebraic expression with constant coefficients. The coefficients are defined on the basis of the stress and the tangent modulus of the confined concrete in three characteristic points of the curve, thus being related to physical meaningful parameters. It will be shown that if the v…
Experimental application of digital image correlation for the tensile characterization of basalt FRCM composites
2021
Abstract Composites made with inorganic matrix, namely fabric reinforced cementitious mortar (FRCM) composites are becoming widespread as strengthening materials for existing masonry structures. These composites are made of a dry grid of fibres embedded in an inorganic matrix. FRCMs can be considered a valid alternative to traditional organic composites such as fibre reinforced polymers (FRPs) because of their better compatibility with the masonry support. This work presents an experimental study for the tensile characterization of a basalt fabric reinforced cementitious mortar (BFRCM) composite. Tensile tests were carried out on coupons reinforced with one, two or three layers of grid to i…
Masonry columns confined with fabric reinforced cementitious matrix (FRCM) systems: A round robin test
2021
Abstract The conservation and the preservation of existing masonry buildings, most of them recognized as cultural heritage, require retrofitting techniques that should reduce the invasiveness and assure reversibility and compatibility with the substrate. In this perspective, the strengthening system should be able to improve the bearing capacity of the structural member and, at the same time, to assure mechanical and material compatibility. The use of Fabric Reinforced Cementitious Matrix (FRCM) composites is now recognized to be suitable for these purposes. Indeed, the inorganic matrix has comparable properties with respect to the existing historical mortars while the fabric has relevant t…
Formulation of a truss element for modelling the tensile response of FRCM strips
2022
Modelling the tensile behaviour of Fabric Reinforced Cementitious Matrix (FRCM) is not a straightforward task due to the inner complexity of the mechanics of this kind of composite materials. In fact, after that the matrix is cracked, the compatibility between the fibre and the surrounding mortar is lost and the system behaves as two separate elements connected by a brittle interface. For this reason, several research studies proposed computational approaches for evaluating the tensile behaviour of FRCM composites, usually referring to brick-based 3D Finite Element Models (FEM) or to complex numerical procedures. This paper shows the formulation of a simplified coupled truss element for mod…
Constitutive Numerical Model of FRCM Strips Under Traction
2020
In this paper, the tensile behavior of Fiber Reinforced Cementitious Matrix (FRCM) strips is investigated through Finite Element (FE) models. The most adopted numerical modeling approaches for the simulation of the fiber-matrix interface law are described. Among them, the cohesive model is then used for the generation of FE models which are able to simulate the response under traction of FRCM strips tested in laboratory whose results are available in the technical literature. Tests on basalt, PBO and carbon coated FRCM specimens are taken into account also considering different mechanical ratios of the textile reinforcement. The comparison between FE results and experimental data allows val…
ELEMENTI IN CALCESTRUZZO CONFINATI CON FRCM ANALISI SPERIMENTALE PER CARICHI MONOTONICI
2011
Vengono presentati i risultati di prove sperimentali su provini di calcestruzzo rinforzati con fibre di materiale composito, soggetti a compressione monotonica fino alla rottura. In particolare si è sperimentato l’impiego degli FRCM (Fiber Reinforced Cementitiuos Matrix), in cui le fibre di rinforzo sono immerse in una matrice cementizia. I risultati ottenuti dimostrano che il confinamento eseguito con questi materiali conferisce agli elementi di calcestruzzo un significativo aumento di capacità portante e di duttilità, sebbene le percentuali di fibra impiegate non abbiano consentito di ottenere comportamenti costantemente incrudenti fino a rottura. In particolare le curve tensione-deformaz…
Performance Assessment of Basalt FRCM for the Confinement of Clay Brick Masonry Cylinders
2021
Fibre Reinforced Cementitious Matrix (FRCM) composites have been proved to be a suitable strengthening material for masonry structures in the last years. Moreover, basalt fibres are increasingly used as reinforcement of composites as a more sustainable alternative to glass fibres. The goal of this work is to investigate the effectiveness of basalt FRCM to confine masonry circular columns. A total of eighteen clay brick masonry cylinders were tested in compression. The specimens were cored from two different masonry assemblies and wrapped with one or two layers of BFRCM composite. The stress-strain curves and the gains of strength and strain capacity of confined cylinders compared to the con…
An experimental study on the compressive behaviour of calcarenite masonry columns wrapped by fiber reinforced mortar wraps
2018
The use of Fiber Reinforced Cementitious Mortar (FRCM) systems for structural retrofitting of masonry structures has become increasingly popular in the last years, due to the capability of this technique in overcoming some of the drawbacks related to the adoption of resin-based composites. In fact, FRCM systems ensure good compatibility between the reinforcing layers and the substrate, achieving also the removability requirement, which is of fundamental importance for historical constructions. Recent research studies focused on the mechanical performance of FRCM materials, by studying its tensile behaviour and bond between the strengthening layer and masonry, pointing out as failure is alwa…