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• The tensile test is widely used for the characterization of FRCM systems. • The tensile behavior of FRCM involves different phenomena interacting among them. • A theoretical model for studying the tensile behavior of FRCM is proposed. • The reliability of the model is assessed with reference to experimental cases. • The proposed model is a valid support for understanding the experimental outcomes. Fabric Reinforced Cementitious Matrix (FRCM) systems have been recently introduced for repairing or strengthening interventions of reinforced concrete and masonry structures. Thanks to the combination of a dry grid of fibers and a cement-based material (matrix), they present a good strength and numerous advantages with respect to traditional Fiber Reinforced Polymer (FRP) systems. The tensile and bond behavior of FRCM reinforcement systems is characterized by specific phenomena influencing their performance, which are generally not observed in the case of FRP, and that are still object of experimental and numerical studies. Aim of the present paper is the proposal of a theoretical model for numerically studying the tensile behavior of FRCM systems, able to consider the different phenomena characterizing the response of FRCM in tension. The model is carried out on the basis of equilibrium considerations by introducing both linear and nonlinear laws for schematizing the local behavior at the level of the matrix, reinforcement and reinforcement/matrix interface. The model is presented in detail in the first part of the paper and, in the second part, it is applied to an experimental case study derived from literature. [ABSTRACT FROM AUTHOR]

• FRCM composite bond behavior is affected by the presence of interface normal stress. • In modified beam tests the normal stress is directed against the matrix internal layer. • The normal stress increases the bond capacity of modified beam tests. • The effect of the normal stress is related to the specific FRCM composite. In the last decades, the increasing need for strengthening and retrofitting of existing masonry members has led the scientific community toward the development of innovative strengthening systems. Among these systems, inorganic-matrix composite materials have been gaining increasing popularity due to their effectiveness, relatively low cost, ease of the application, and reversibility of the intervention. Inorganic-matrix composites, usually referred to as fiber- (or fabric-) reinforced cementitious matrix (FRCM) composites, were successfully used as externally bonded reinforcement (EBR) of masonry members subjected to various load combinations. However, their effectiveness is strictly related to the FRCM-substrate bond behavior. Therefore, numerous set-ups were employed to investigate the bond properties of FRCM composites. Among them, single-lap direct shear test set-ups were the most commonly employed and are now recommended by available design guidelines for FRCM composites. In this paper, a modified beam (MB) test set-up is used to study the bond behavior of two different FRCM composites: a polyparaphenylene benzobisoxazole (PBO) FRCM and a carbon FRCM. The parameters studied are the dimensions of the blocks used in the MB tests and the presence of bare or embedded fibers at the gap between the blocks. The bond behavior observed is compared with that of single-lap direct shear tests of the same FRCM composites. The results obtained provide an insight on the influence of normal stress components at the matrix-fiber interface on the FRCM bond behavior, which may play an important role in the capacity of FRCM strengthened curved members. [ABSTRACT FROM AUTHOR]

• Textile-to-mortar bond behaviour in lime-based textile reinforced mortars is experimentally and analytically investigated. • 160 pull-out tests are performed on two TRM composite types. • The role of test setup, loading rate, mortar age, fabric configuration and embedded length are discussed. • The results contribute to standardization of test methods and fundamental understanding of the bond behaviour in TRM composites. • The results contribute to development and design of TRM composites with enhanced properties. Lime-based textile-reinforced mortars (TRM) have recently found a growing interest for repair and strengthening of masonry and historical structures. Despite extensive experimental and numerical investigations performed in the last years on the performance of these composites, there is still a lack of fundamental understanding of the fabric-to-mortar bond behaviour (as one of the main mechanisms affecting the cracking and nonlinear response of these composites) and the parameters affecting that. This paper, aimed at addressing this gap, presents a comprehensive experimental and analytical investigation on how the test setup, embedded length, load rate, mortar age and fabric configuration affect the bond behaviour in lime-based TRMs. In total 160 pull-out tests are performed on a glass-based and a steel-based TRM commonly used for strengthening of masonry structures. The results contribute to standardization of the test procedures for characterization of the fabric-to-mortar bond behaviour, to fundamental understanding of this mechanism and to optimization of the design of these composites for enhancing their mechanical response. [ABSTRACT FROM AUTHOR]