The experimental characterization of a Natural Fiber Reinforced Cementitious Matrix (NFRCM), made of sisal fibers yarns impregnated with a water-based resin and embedded in a inorganic matrix based on natural lime, is presented in the paper. The Sisal-NFRCM performances are investigated through tensile and single-lap shear tests, adopting the dispositions of the Round Robin Tests developed for the FRCM characterization by the RILEM Technical Committee 250-CSM. The tensile stress-strain curve evidenced the tension stiffening effect of the mortar between cracks, which tended progressively to reduce. In shear tests, the failure and the progressive slippage of the sisal yarns was observed.

In this work the behavior of masonry arches, without reinforcement and with partial reinforcement, is investigated by means of three different numerical models. The first one is a Discrete Element model based on rigid blocks, and elastic-plastic interfaces; the second one is a standard heterogeneous Finite Element Model, which is adopted for a detailed micro-modelling of arch voussoirs, joints, and reinforcements. The third model is analytic-numerical, and it is adopted for validating the other numerical results. The aim of the work is the comparison and validation of the numerical Finite and Discrete Element models for the correct simulation of masonry arch behavior, together with the evaluation of the effectiveness of these models in simulating the behavior of the partially reinforced arch.

An experimental and numerical investigation on an innovative composite reinforced with sisal fibers for masonry strengthening is presented in this paper. A FEM numerical approach is also developed, based on diagonal compression test results, to simulate the shear in-plane response of unreinforced masonry panels (URM) and masonry strengthened with a Fibre Reinforced Cementitious Matrix (FRCM) composite system made with sisal fibers (RM-SISAL).

In this work, a refined rigid block model is proposed for studying the in-plane behavior of regular masonry. The rigid block model is based on an existing discrete/rigid model with rigid blocks and elastoplastic interfaces that already proven its effectiveness in representing masonry behavior in linear and nonlinear fields. In this case, the proposed model is improved by assuming rigid quadrilateral elements connected by one-dimensional nonlinear interfaces, which are adopted both to represent mortar (or dry) joints between the blocks and also to represent inner potential cracks into the blocks. Furthermore, the softening behavior of interfaces in tension and shear is taken into account. Several numerical tests are performed by considering masonry panels with regular texture subjected to compression and shear. Particular attention is given to the collapse mechanisms and the pushover curves obtained numerically and compared with existing numerical and laboratory results. Furthermore, the numerical tests aim to evaluate the applicability limits of the proposed model with respect to existing results.

No abstract