Fabric Reinforced Cementitious Matrix Systems Research Articles

Experimental Investigation of Concrete Cylinders Confined with PBO FRCM Exposed to Elevated Temperatures

Externally bonded fiber-reinforced polymers (FRPs) have been widely used for strengthening and retrofitting applications. However, their efficacy is hindered by the poor resistance of their epoxy resins to elevated temperatures and their limited compatibility with concrete substrates. To address these limitations, fabric-reinforced cementitious matrix (FRCM), also known as textile reinforced mortar (TRM), systems have emerged as an alternative solution. In this study, experimental tests were performed on concrete cylinders confined with FRCM systems that consisted of mineral mortar and poliparafenilenbenzobisoxazole fabric (PBO). The cylinders with concrete strengths of 30, 45, and 70 MPa, were confined with one or two FRCM layers, and were subjected to different target temperatures (100, 400, and 800 °C). The experimental results highlighted the confinement effect of FRCMs on the compressive strength of the tested cylinders. Cylinders exposed to 100 °C exhibited a slight increase in their compressive strength, while no specific trend was observed in the compressive strength of cylinders heated to 400 °C. Specimens heated up to 800 °C experienced a significant reduction in strength, reaching up to 82%.

Experimental Research on Seismic Performance of Masonry-Infilled RC Frames Retrofitted by Using Fabric-Reinforced Cementitious Matrix Under In-Plane Cyclic Loading

Fabric-reinforced cementitious matrix (FRCM) composites, also known as textile-reinforced mortars (TRMs), represent a new advancement in structural repair and reinforcement technology. Aiming to improve the energy efficiency and seismic performance of existing buildings, this research focused on the development of an FRCM system in combination with phase change materials (PCMs) and extruded polystyrene sheets (XPS) to achieve adequate mechanical and thermal properties for reinforced concrete (RC) and masonry structures. Accordingly, the in-plane behaviour of five FRCM-strengthened RC frames with hollow-brick wall infill was tested under cyclic loading to investigate the improvement in earthquake resistance. The system was comprehensively evaluated by calculating hysteresis curves; comparing the lateral stiffness, ductility, and energy dissipation capacity; measuring the deformations of the specimens; and analysing the failure modes mechanically. Finally, it was proved that this novel integrated approach could significantly enhance the mechanical and seismic performance of masonry-infilled RC frames.

Symmetric and Asymmetric Strengthening of Two-Span RC Beams Using FRCM Systems

This paper reports on the feasibility of using fabric-reinforced cementitious matrix (FRCM) systems to strengthen two-span reinforced concrete (RC) beams that are structurally deficient in their sagging regions. In addition to one unstrengthened control beam, nine beams strengthened either symmetrically or asymmetrically with polyparaphenylene benzobisoxazole (PBOFRCM), carbon (CFRCM), and carbon fiber–reinforced polymer (CFRP) sheets were tested under a five-point load configuration. Test results showed that increasing the strengthening ratio resulted in significant increases in the yielding and load-carrying capacity of the beams. Beams symmetrically strengthened with PBOFRCM showed high ductility indices ranging between 100% and 121% of that of the control beam, whereas those strengthened with CFRCM and CFRP showed ductility indices of 45% and 34% of that of the control beam, respectively. Moreover, beams symmetrically strengthened with PBOFRCM systems encountered moment redistribution ratios between 42% and 82% of that of the control beam compared with 10% and 9% only for those strengthened with CFRCM and CFRP systems, respectively. The asymmetric strengthening configuration in which FRCM systems were used along with CFRP sheets proved to be an efficient method to enhance the ductility and moment redistribution capacity of the strengthened beams. Analytically, the rigid-body-rotation approach was modified to predict the moments and curvatures at the plastic hinges of the strengthened sections. The predicted moments and curvatures showed a notable agreement with the experimental values.

Experimental investigation on the use of Fabric‐Reinforced Cementitious Mortars for the retrofitting of reinforced concrete dapped‐end beams

AbstractThe structural performance and durability of reinforced concrete (RC) dapped‐end beams may be significantly threated by the effects of deterioration and environmental actions, compromising the structural robustness of important infrastructures such as bridges. The study of the critical role of dapped‐ends has grown in recent years, focusing in particular on the implementation of innovative retrofit solutions capable of extending the service life of these structural elements. In this paper, an experimental investigation on the contribution of Fabric‐Reinforced Cementitious Matrix (FRCM) retrofitting system to the load bearing capacity of RC dapped‐end beams is presented. A set of eight full‐scale dapped‐ends was subjected to monotonic loading tests. The presence of cracks prior to the application of the retrofitting composite, which may represent the actual state of conservation of existing RC half‐joints subjected to heavy traffic loads, is reproduced by testing the specimens up to the reaching of the ultimate design load. Different orientations of the alkali‐resistant glass fabric composing the FRCM system were tested, and the results allow to discuss the effectiveness of the retrofitting solution.

FRCM-to-masonry bonding behaviour in the case of curved surfaces: Experimental investigation

Fabric-reinforced cementitious matrix (FRCM) are composite materials more and more used for the reinforcement of masonry structures. The combination of high tensile strength fabrics (or meshes) with cementitious matrices, having good thixotropic capabilities and vapour permeability, makes such composites suitable for reinforcing a large number of masonry structures, including the one belonging to the historic heritage. FRCMs are bonded to the outer surfaces of structural masonry elements and, thanks to their adhesive capacity, bear much of the tensile stresses that unreinforced masonry cannot withstand. The effectiveness of such reinforcements, which is highly dependent on their ability to adhere to the masonry substrate, is generally investigated throughout specific experimental investigations (shear tests). Almost all the papers in the literature devoted to bond-slip analysis refer to the case of flat bonding surfaces, although these reinforcements are also widely used on curved structural elements such as arches and vaults. Therefore, this paper reports and examines the results of an extensive experimental program concerning the behavior of FRCM systems applied on curved masonry specimens. The results point out the influence of both curvature and reinforcement position (intrados or extrados) on the response of specimens in terms of bearing capacity, failure mode and post-peak response.

Compressive Strength of Masonry Confined by FRCM Systems: Assessment of Existing Models and New Proposals

Fabric-reinforced cementitious matrix (FRCM) composites have emerged as a viable solution for the external confinement of masonry members. However, what still discourages the use of these composites in the civil engineering field is the lack of analytical models capable of estimating the compressive strength of FRCM confined members with appreciable accuracy.This paper contributes to filling this knowledge gap by presenting an analytical study on the compressive strength of masonry confined by FRCM systems. The goal is twofold: a) to assess existing formulae published in the literature or in some international guidelines, and b) to provide new and more accurate proposals. To this purpose, a large database including results of compression tests on masonry members wrapped with FRCM systems was compiled from the literature. The database was organized by considering some relevant parameters, such as: type of fiber and geometry of the mesh, number of employed layers, mechanical properties of the inorganic matrix, compressive strength of the masonry. The accuracy of the strength models is examined by both considering all FRCM confined members together and treating natural and artificial masonry separately.

Clevis-Grip Tensile Tests on Basalt, Carbon and Steel FRCM Systems Realized with Customized Cement-Based Matrices

The tensile properties of fabric-reinforced cementitious matrix (FRCM) composites are experimentally investigated through clevis-grip tensile tests (according to AC434 provisions) on FRCM coupons realized with customized (ad hoc developed in this paper) cement-based matrices. The tested FRCM coupons are reinforced with basalt, carbon, or steel fabrics, and are prepared with three different matrices: one-component mortar incorporating dispersible copolymer powders of vinyl acetate and ethylene (matrices A and B) and two-component mortar with carboxylated styrene–butadiene copolymer liquid resin (matrix C). This has made it possible to investigate the mechanical compatibility between different mortar matrices and fabrics and the resulting tensile properties of FRCM composites in the uncracked, cracking, and fully cracked phases. Experimental results are critically analyzed in terms of stress–strain curves and failure mechanisms comparatively for the analyzed FRCM systems. It has been shown that the matrix B exhibits a good compatibility with the basalt pre-impregnated fabric, while the matrix C appears to be the most suitable candidate to optimize the interfacial stress transfer at the fiber–matrix interface for all fabrics, thus exalting the mechanical performances in terms of tensile strength and ultimate strain. The results of this experimental program can be useful for designing optimized mortar mixes aimed at realizing novel FRCM composites or at improving existing FRCM systems by suitably accounting for compatibility behavior and slippage at the fabric–matrix interface.

EFFECT OF CURVATURE ON THE TENSILE STRENGTH OF FRCM

Fabric reinforced cementitious matrix (FRCM) systems are promising composite materials which are increasingly used for the strengthening of reinforced concrete components. The interaction of high performance, fine-grained concretes and noncorrosive, high strength textile reinforcements combines many advantages of shotcrete linings and externally bonded fiber-reinforced polymers (FRP). For this reason, especially the retrofitting of plane concrete structures with FRCM has already been investigated appropriately. However, the application of FRCM systems in edge regions and curved areas, such as the confinement of reinforced concrete columns or shear strengthening of beams, leads to a reduction of the systems' tensile strength. This reduction is mainly caused by additional transverse pressure, cracks in the concrete matrix, and possible pre-damage due to the bent textile. As most available prediction models use static reduction factors, the dependencies of these influences have not been considered sufficiently yet. This paper presents an experimental study regarding the effects of curvature on the tensile strength of FRCM-strengthening layers. Therefore, 93 specimens with varying radii, FRCM composite materials, and numbers of applied textile layers were tested in a newly developed setup. The test results show significant dependencies on the various parameters and contrast with the static reduction factors used so far.

EFFECT OF CURVATURE ON THE TENSILE STRENGTH OF FRCM

Fabric reinforced cementitious matrix (FRCM) systems are promising composite materials which are increasingly used for the strengthening of reinforced concrete components. The interaction of high performance, fine-grained concretes and noncorrosive, high strength textile reinforcements combines many advantages of shotcrete linings and externally bonded fiber-reinforced polymers (FRP). For this reason, especially the retrofitting of plane concrete structures with FRCM has already been investigated appropriately. However, the application of FRCM systems in edge regions and curved areas, such as the confinement of reinforced concrete columns or shear strengthening of beams, leads to a reduction of the systems' tensile strength. This reduction is mainly caused by additional transverse pressure, cracks in the concrete matrix, and possible pre-damage due to the bent textile. As most available prediction models use static reduction factors, the dependencies of these influences have not been considered sufficiently yet. This paper presents an experimental study regarding the effects of curvature on the tensile strength of FRCM-strengthening layers. Therefore, 93 specimens with varying radii, FRCM composite materials, and numbers of applied textile layers were tested in a newly developed setup. The test results show significant dependencies on the various parameters and contrast with the static reduction factors used so far.

Fabric-Reinforced Cementitious Matrix (FRCM) Carbon Yarns with Different Surface Treatments Embedded in a Cementitious Mortar: Mechanical and Durability Studies.

Nowadays, FRCM systems are increasingly used for the strengthening and retrofitting of existing masonry and reinforced concrete structures. Their effectiveness strongly depends on the bond that develops at the interface between multifilament yarns, which constitute the reinforcing fabric, and the inorganic matrix. It is well known that fabric yarns, especially when constituted by dry carbon fibers, have poor chemical-physical compatibility with inorganic matrices. For this reason, many efforts are being concentrated on trying to improve the interface compatibility by using different surface treatments on multifilament yarns. In this paper, three different surface treatments have been considered. The first two involve yarn pre-impregnation with flexible epoxy resin or nano-silica coating, while the third one involves a fiber oxidation process. Uniaxial tensile tests were carried out on single carbon yarns to evaluate tensile strength, elastic modulus and ultimate strain before and after surface treatments, and also after yarn exposure to accelerated artificial aging conditions (1000 h in saline or alkaline solutions at 40 °C), to evaluate their long-term behavior in aggressive environments. Pull-out tests on single carbon yarns embedded in a cementitious mortar were also carried out, under normal environmental conditions and after artificial exposure. Epoxy proved to be the most effective treatment, by increasing the yarn tensile strength of 34% and the pull-out load of 138%, followed by nano-silica (+9%; +40%). All surface treatments were shown to remain effective even after artificial environmental exposures, with a maximum reduction of yarn tensile strength of about 13%.

Strengthening pre-damaged RC square columns with fabric-reinforced cementitious matrix (FRCM): Experimental investigation

This study investigates the effectiveness of using fabric-reinforced cementitious matrix (FRCM) systems in repairing pre-damaged reinforced concrete (RC) square columns. Two groups of columns were fabricated and tested under concentric loading up to failure. Columns of each group had different spacing between their transverse reinforcement to investigate the effectiveness of FRCM reinforcement in confining the columns. The columns were subjected to two pre-damaging criteria prior to strengthening. Four columns were loaded up to their yielding capacity and then unloaded while the other two columns were subjected to three cycles of fatigue loading that ranged between 2% and 75% of the unstrengthened column’s capacity. The pre-damaged columns were then strengthened with either two or four layers of polyparaphenylene-benzobisoxazole (PBO)–FRCM system. Test results showed that confining the pre-damaged columns with PBO–FRCM systems resulted in 7–42% enhancement in their load–carrying capacity and 47–272% improvement in their ductility. The predicted columns’ capacity calculated as per ACI 549 guidelines showed a good agreement with the experimental results. The experimental–to–predicted capacity ratio ranged between 0.82 and 1.03 for columns with tie spacing of 180 mm and between 0.92 and 1.09 for columns with tie spacing of 90 mm.

Failure Modes of RC Structural Elements and Masonry Members Retrofitted with Fabric-Reinforced Cementitious Matrix (FRCM) System: A Review

Much research has been conducted and published on the examination of the behavior of reinforced steel and concrete structures with a FRP system. Nevertheless, the performance of FRP differs from that of FRCM, particularly at high temperature and ultimate strength. The present study provides a review of previous research on structural elements (viz. beams, columns, arches, slabs, and walls) retrofitted with FRCM systems, taking account of various parameters, such as layers, composite types, configurations, and anchors for controlling or delaying failure modes (FMs). Additionally, this paper discussed the details of different FMs observed during experimental tests, such as crushed concrete or bricks, fiber debonding from substrate materials, slippage, fiber rupture, and telescopic failure for strengthened specimens. Moreover, this paper investigated where and how fractures may develop in structural elements retrofitted with the FRCM system under various retrofit scenarios. To this end, in addition to the review of the relevant literature, a large dataset has been compiled from different (RC) structural elements and masonry members. Next, a relationship is developed between failure modes (FMS) and influential parameters, i.e., the number of layers and the type of composite, based on this dataset. This can be used as a benchmark example in future studies, as there is no such basis available in the literature, to the best of the authors’ knowledge.

Mechanical Behaviour of Glass Fibers FRCM and CRM Systems after Ageing in Alkaline Environments

Fabric Reinforced Cementitious Matrix (FRCM) and Composite Reinforced Mortar (CRM) are used in structural strengthening of heritage masonry construction due to their high compatibility with the substrate. Due to the interaction between the reinforcement fibers, made by glass or basalt, and the alkaline matrix, durability problems may be met in the field. In this study a large experimental program is presented and discussed in a synthetic form, with reference to glass fibers reinforcements used in FRCM and CRM systems. Ageing conditions were reproduced in a laboratory environment by immersing the glass-fibre reinforcements into three different solutions. The artificial alkaline solutions used in this study simulated the chemical aggression of lime mortar matrix, Portland cement matrix and standard alkaline solutions (ASTM standard). Four conditioning periods were applied as ageing protocol: 500hrs, 1000hrs, 2000hrs and 3000hrs. Accelerating effects were produced by increasing the temperature during ageing, from 23°C to 40°C and 70°C. The residual mechanical properties and physical damage observed by using Scanning Electronic Microscopy (SEM) are discussed in the paper. The decay of the mechanical properties is highlighted in terms of tensile strength on the whole FRCM strengthening system and for each of the constituents.

Influence of Freeze/Thaw and Alkaline Environment on the Mechanical Properties of a C-FRCM System Bonded on Masonry Substrate

The Fabric Reinforced Cementitious Matrix (FRCM) system in the last two decades was used to strengthen and rehabilitate historical masonry structures as an alternative of the well-known Fiber-Reinforced Polymer (FRP) system. The FRCM systems consist of different types of fiber in form of fabric mesh immersed in a cementitious/hydraulic or lime matrix; they present better compatibility with the substrate and less limitations in heritage applications. However, the durability and the interaction FRCM-substrate under the artificial aging mechanism in aggressive environment is not well known. The paper reports and discuss the first results of an experimental program planned to investigate the durability of some FRCM systems. The effects of the freeze/thaw and alkaline environment on both the mechanical properties of the FRCM coupons and the bond FRCM-to-masonry substrate were analyzed by the results of direct tensile and single-lap shear tests.

A Numerical Study to Predict the Mechanical Response of FRCM Composites

Fabric Reinforced Cementitious Matrix (FRCM) materials are increasingly common for strengthening existing masonry structures. Their popularity is due to their many advantages with respect to resin-based composites, especially when applied to stone supports. The constitutive behaviour of FRCM materials is defined by the combination of their tensile response and the bond behaviour with the masonry support, both depending on complex stress transfer mechanisms between matrix and fabric, especially in the post-cracking stage. This paper presents a numerical study which aims to predict the mechanical behaviour of FRCM systems through simple 2D models of truss elements and non-linear springs to simulate the fabric-to-matrix and composite-to-substrate interaction. The comparisons between results of numerical approach and experimental responses showing that the proposed methodology is an effective and easy tool to predict the mechanical behaviour of FRCM composites.

Stainless steel-FRCM system for strengthening of RC beams: towards a sustainable strengthening technique

Fabric-Reinforced Cementitious Matrix (FRCM) systems for strengthening concrete structures are an alternative to traditional techniques. The FRCM system is a composite material consisting of two or more layers of cement-based matrix reinforced with dry fibres in the form of open mesh or fabric. When adhered to concrete structural members the FRCM system acts as supplemental external reinforcement. Many existing Reinforced Concrete (RC) members exhibit degradation due to the carbonation of concrete and/or corrosion of internal reinforcing steel bars. These RC members can be strengthened using stainless steel, in strip format (unidirectional fibres), embedded in a cementitious based matrix. The system, named Stainless Steel-FRCM, can be applied according to the Externally Bonded (EB) technique. In order to reduce times and costs of intervention, number of used materials, as well as the amount of chemical compounds, a novel Inhibiting-Repairing-Strengthening (IRS) technique is proposed and experimentally tested. Using a suitable matrix (thixotropic mortar with passivation properties) the main three operations of steel bars corrosion inhibition/protection, restoring of deteriorated concrete, and installation of the external strengthening can be carried out in one-step. For evaluating the effectiveness of both new strengthening system and installation technique an extensive experimental investigation was planned and developed. A part of the experimental research includes two groups of three RC beams (3.00 m and 4.80 m long): one strengthened withIRS technique, one strengthened with EB technique and one control beam. These beams were tested under monotonic loading. Further two beams, one beam for each group, strengthened according to IRS technique, were also tested under cyclic loading. The experimental results show the validity of the proposed solution in terms of structural performance and environmental sustainability.

Performance of FRCM composites and FRCM-strengthened RC beams subjected to anodic polarization and cyclic loading

Fabric reinforced cementitious matrix (FRCM) systems can provide structural strengthening (SS) of aging reinforced concrete (RC) structures. Furthermore, impressed current cathodic protection (ICCP) has been integrated with FRCM systems to develop ICCP-SS intervention systems to help improve the long-term performance of FRCM-strengthened RC structures. However, there is a lack of research regarding the fatigue performance of FRCM composites and FRCM-strengthened RC members. This study investigated the effects of fabric layers in carbon-FRCM, anodic polarization in the process of ICCP, and cyclic loading conditions on the fatigue performance of FRCM composites in tension and FRCM-strengthened RC beams in flexure. Cyclic tensile loading tests of FRCM specimens and cyclic four-point bending tests of beam specimens were conducted. Cyclic tensile test results showed that the fatigue life performance of FRCM was superior to that of steel rebar and inferior to that of carbon fiber reinforced polymer (CFRP, a composite that commonly has an epoxy resin matrix). The anodic polarization of ICCP degraded the fatigue life of carbon-FRCM at a given stress level and fatigue strength after two million loading cycles. The cyclic bending test results indicated that the fatigue performance of the beams was largely dependent on the number of fabric layers in the FRCM and slightly influenced by the anodic polarization in the ICCP-SS. A new curve of the steel stress range versus the number of cycles (S-N curve) for FRCM-strengthened beams was obtained in this study and provided satisfactory fatigue life predictions.

Numerical simulation of masonry walls strengthened with vegetal fabric reinforced cementitious matrix (FRCM) composites and subjected to cyclic loads

The growing concern for the preservation of old buildings and the wide use of masonry in the construction of civil works has led to a great development of specific techniques to strengthen masonry structures. FRCM (fabric reinforced cementitious matrix) of vegetal fibres arises as a strengthening option to be considered because low cost, low density, recyclability and biodegradability brought by vegetal fibres. In this study, numerical models were used to represent masonry walls unreinforced and strengthened with FRCM (hemp, cotton and glass). The numerical model presents a new way of simulation of FRCM systems and their failure pattern. This was validated by comparison to previous experimental and analytical results. Results showed that proposed model is an effective calculation tools to reproduce the maximum shear of masonry walls strengthened with FRCM and subjected to cyclic loads, with variations between 7 and 15% with respect to the experimental and analytical. The numerical model was also useful to reproduce the walls hysteresis behavior, although showed some inability to reproduce the reversible crack opening-closing that was observed in the experimental tests.

Assessment and modeling of the debonding failure of fabric-reinforced cementitious matrix (FRCM) systems

This paper aims at developing a model that is capable to accurately predict the debonding strains in reinforced concrete (RC) members strengthened with fabric-reinforced cementitious matrix (FRCM) systems. A large database consisting of 393 shear bond specimens strengthened with Polyparaphenylene Benzobisoxazole (PBO), Carbon (C), Glass (G), and Steel (S) FRCM systems was firstly compiled from the published literature. A sensitivity analysis was carried out to identify the key parameters that most affected the debonding mechanism in FRCM. The notable influence of the compressive and tensile strengths of the concrete substrate, the compressive strength of FRCM mortar, and the axial stiffness of FRCM system on the debonding strains in FRCM systems was evidenced. Contrarily, the tensile strength of FRCM mortars showed slight or no impact on the FRCM debonding strains. Based on the results of the sensitivity analysis, three simple models were developed using a multivariate nonlinear regression analysis. The models were then optimized and validated against the experimental results of 41 flexural members strengthened with different types of FRCM systems. Two of the three models proved an excellent prediction performance of the debonding strains with an average predicted–to–experimental strain ratios, εpred/εexp, of 0.99 ± 0.27 and 1.02 ± 0.27 with coefficients of variation (COV) of 0.28 and 0.26, respectively. Both models could safely predict the debonding strains in FRCM-strengthened members regardless of the type of FRCM system used. Neglecting the tensile strength of the concrete substrate in the third model resulted in an average εpred/εexp ratio of 0.85 ± 0.37 with a COV of 0.44.

Masonry columns confined with fabric reinforced cementitious matrix (FRCM) systems: A round robin test

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 tensile strength. At the same time, these systems assure satisfactory level of reversibility (or at least removability). In this scenario, the present research aims to investigate the FRCM-confinement of masonry columns focusing on the influence of specific parameters, still poorly investigated, in order to deeply understand their effect on the mechanical response. In particular, the experimental variables are: the type of masonry substrate (Tuff and clay brick with lime-based mortar), the type of FRCM system (glass dry mesh + lime-based mortar and steel mesh + lime-based mortar) and the number of plies (1, 2 and 3). In addition, a detailed experimental characterization of the utilized materials has been carried out, including bond tests between the reinforcement and the substrate. The results evidenced that the FRCM is an effective solution for masonry columns confinement once a proper design is performed, taking into account all involved parameters. The different strengthening systems exhibited different failure modes. Generally, a single ply of external reinforcement produced a negligible increase of bearing capacity. Both strengthening systems applied with multi-ply strengthening schemes produced a significant increase in terms of strength and ultimate axial deformation. This benefit was observed for both Tuff and clay masonry columns. Two available design-oriented formulas, reported in the Italian CNR (National Research Council) and ACI (American Concrete Institute) guidelines have been utilized, in order to further investigate their accuracy, mostly in the case of multi-layered reinforcement. The performed comparisons highlight that the two design relationships provide similar and accurate results when referred to the GFRCM (Glass-FRCM) system in 1- and 2-layer configurations, while the predictions appear conservative when 3 layers of GFRCM are utilized, for both masonry types. Considering the SRG (Steel Reinforced Grout) system, the results predicted by the two models are more scattered, mostly when the number of layers increases. In addition, the formulation proposed by CNR appears more accurate in the case of Tuff masonry while the ACI predictions are closer to the experimental results in the case of clay brick masonry.