Outcomes

Abstract:

A macro-modeling strategy for masonry elements strengthened by using the Composite Reinforced Mortar (CRM) system is presented in the paper. The CRM system consists in the application, on the walls surface, of a mortar coating reinforced with pre-formed composite meshes, based on long fibers, and in the installation of connectors in the masonry thickness. The numerical strategy, developed by using of the free, open-source, finite elements code OOFEM, is based on multi-layer elements, composed of plies oriented along the wall thickness, representing the masonry, the plaster and fiber-based reinforcement.

Non-linear static analyses are performed; a "Concrete Damage Plasticity" material model is adopted for both the masonry and the mortar coating, while, for the equivalent layer representing the composite mesh, an elastic-brittle behavior in tension is considered. The characteristics of the materials are independently calibrated on the basis of the results of experimental tests performed on unstrengthened masonry, on mortar samples, on composite yarns and on CRM coupons. The model is applied to simulate the in-plane and out-of-plane behavior of CRM strengthened piers; the results are compared with experimental outcomes coming from in-plane shear-compression tests and out-of-plane three-point bending tests performed on rubble stone samples (350 mm thick). The comparison shows that the simplified model is able to realistically reproduce the experimental results both in terms of resistance and displacement capacities and in terms of failure modes.

Citation: Boem, I.,Patzák, B., Kohoutková, A. Study on the effectiveness of the CRM system: numerical simulations on masonry piers with OOFEM layered elements, Procedia Structural Integrity 2023, 44, 2238-2245, https://doi.org/10.1016/j.prostr.2023.01.286

This work is made available under the terms of the Creative Commons Attribution 4.0 International license (CC BY-NC-ND 4.0).

Abstract:

Composite Reinforced Mortar (CRM) and Fiber-Reinforced Cementitious Matrix (FRCM) are two modern strengthening techniques for existing masonry, based on the coupling of fiber-based grids and inorganic matrices, applied on the masonry surface. They typically differ for the thickness of the coating (20-40 mm in the former, 8-15 mm in the latter) and the type of embedded reinforcement (pre-coated meshes with wide pitch or dry fabrics with a closer yarns spacing, respectively). To prove their effectiveness in the seismic protection of historical masonry vaulted ceilings, experimental cyclic tests were performed on full-scale thin barrel vault samples subjected to a distributed transversal load. The results are analysed and discussed in the paper: it emerged a good effectiveness of both the strengthening solutions, with significant benefits in both resistance and displacement capacities. Moreover, a key aspect for the reinforcement effectiveness is found in the connection of the composite systems with the abutments. Numerical non-linear static analyses based on a simplified multi-layer approach developed in the OOFEM code allow to analyse the resisting mechanisms and investigate on the reinforcement effectiveness.

Citation: Boem, I., Gattesco, N. Composite Reinforced Mortar (CRM) and Fiber-Reinforced Cementitious Matrix (FRCM) for the seismic protection of masonry vaults, Procedia Structural Integrity 2023, 44, 1260-1267, https://doi.org/10.1016/j.prostr.2023.01.162

This work is made available under the terms of the Creative Commons Attribution 4.0 International license (CC BY-NC-ND 4.0).

Abstract:

Historic masonry characterizes large part of the building heritage in Europe and worldwide but may suffer for structural weaknesses related to material deterioration, long-term fatigue, over-time modifications, accidental actions, seismic vulnerability... For the structural refurbishment of these building assets, the use of fiber-based composites has widely spread within the last twenty years as strengthening strategy. In particular, the coupling of fiber-based meshes or textiles with mortar plasters (the so-called Textile Reinforced Mortar technique) gained great relevance due to effectiveness, easiness of installation, compatibility of materials, durability and reversibility. The development of design methods for this new technique requires, beside a robust experimental database, also reliable and optimized numerical strategies for the performance estimations. In this context, the paper introduces a simplified finite-element modelling approach, based on multi-layered 3D elements, for the assessment of the structural performances of masonry assemblages strengthened with Textile Reinforced Mortar (TRM). In particular, the free, open source, finite element code OOFEM is adopted to perform non-linear static analyses of masonry samples subjected to in-plane or out-of-plane actions. Brick elements with laminated material composition are adopted for the simulations, with layers stacked along the sample thickness: the inner layer for the masonry and a couple of outer layers for the plaster and for the fiber-based reinforcement. The Gauss integration rule is used for setting up integration points in each layer, which number can be specified independently for each layer. The materials mechanical parameters for each layer are set in accordance to the results of experimental characterization tests available in the literature. The reliability of the simulations is assessed through comparison with previous experimental outcomes concerning tests on TRM strengthened masonry elements, namely diagonal compression tests, in-plane three-point bending tests and out-of-plane four-point bending tests. The model is feasible to reproduce the typical failure modes of masonry elements for both in-plane actions (diagonal cracking and in-plane bending failure) and out-of-plane actions (out-of-plane bending failure) also at advanced damage levels and thus can represent a useful and optimized tool to investigate on wider samples, such as entire walls with openings, even under combined in- and out-of-plane loading.

Citation: Boem, I., Patzák, B., Kohoutková, A. Masonry elements strengthened with TRM: Modelling in “OOFEM” by using multi-layered 3D elements. AIP Conf. Proc. 27 September 2023; 2928 (1): 150004. https://doi.org/10.1063/5.0173732

This work is made available under the terms of the Creative Commons Attribution 4.0 International license (CC BY-NC-ND 4.0).

Abstract:

The lectures were held during the "Interreg ITALIA- SLOVENIJA CONSTRAIN seminars", addressed to Professional Associations of Civil Engineers and Civil Engineering students, and concerned modelling stretegies for masonry strengthened with composites. The lectures constituted a great opportunity to spread the outcomes of the "conFiRMa" project among current and future professional designers and to promote cooperation among EU funded projects. 

a) 9th June 2022 - Professional Association of Engineers, Province of Pordenone 

b) 24th June 2022 - Professional Association of Engineers, Province of Trieste and Province of Gorizia + Civil Engineering Students of University of Trieste

c) 15th July 2022 - Professional Association of Engineers, Province of Udine

Abstract:

The keynote lecture opened the PhD workshop of the CVUT Department of Concrete and Masonry Structures. The lecture traced the main steps of a broad research path conducted on a particular TRM technique, called Composite Reinforced Mortar, describing the experimental testing and numerical modeling experiences aimed at achieving a in-depth knowledge on its behavior and on its effectiveness on the masonry performances.

Abstract:

Marie Curie Alumni Assosiation members are encouraged and welcomed to present their research work, project objectives or experiences at the General Assembly and Annual Conference. The Poster Session is planned to give members a chance to share their discoveries and experiences. Selected posters are showcased during a dedicated session. 

The Book of Abstracts of the poster sessions has been published (ISBN 978-94-6433-602-3, DOI 10.5281/zenodo.6608826)

Abstract:

The seminar, addressed to the bachelor students attending the course "Concrete Structures 2", is aimed at giving an overview of the seismic vulnerability of existing masonry buildings and of the available strengthening techniques to improve their performances.

Abstract:

The OOFEM group at ČVUT organizes seminars to share knowledge, insights and results. The seminars are hybrid, with physical participation of local users and remote participation for guests. In this seminar, the outcomes of the conFirMA project related to the detailed level modelling approach have been presented.

Abstract:

A detailed level numerical model for Fibre Reinforced Mortar (FRM) using the free, opensource code OOFEM has been recently calibrated and validated by the authors through comparisonwith experimental characterization tests (i.e. pull-off tests, tensile tests and shear bond tests). In thispaper, the developed model is adopted to perform numerical simulations on FRM strengthenedmasonry elements. In particular, out-of-plane and in-plane bending tests and in-plane diagonalcompressiontests are simulated by adopting the same modelling hypostasis and characteristics andthe results are compared with experimental tests available in the literature. Both the masonry and themortar are modeled through solid elements, the yarns of the fibre-based mesh with truss elements andthe interactions among the components (yarns, mortar, masonry) by means of interface elements.Non-linear static analyses are performed, considering the materials and interfaces non-linearity. Thesimulations result capable to realistically reproduce the typical performances of masonry elements interms of global performances and damage pattern and permit to investigate on the resistingmechanisms and on the interactions between the components. 

Citation: Boem I., Patzák B., Kohoutková A., 2022, "Numerical Simulations of Masonry Elements Strengthened through Fibre-Reinforced Mortar: Detailed Level Modelling Using the OOFEM Code", Key Engineering Materials, 916, 222–229. https://doi.org/10.4028/p-3p7003

This work is made available under the terms of the Creative Commons Attribution 4.0 International license (CC BY 4.0).

Abstract:

The workshop was held in the context of the "Fibrenet-Roefix Academy 2021", addressed to the Civil Engineers of Croatia. It was articulated in the following sections: preliminary outcomes of the advanced numerical modelling, calibration of numerical models based on experimental test results, definition of analytical formulations from the detailed numerical modelling and applicative examples.

Abstract:

The “conFiRMa” project is aimed at calibrating a numerical model, validated in the free open source finite element code OOFEM, for the assessment of the structural performances of historic masonry buildings strengthened with Fibre Reinforced Mortar (FRM). The main purpose is to develop a multiple-level approach, starting with the detailed modeling of components (masonry, mortar matrix, fibre-based reinforcement), followed by an optimization procedure to get a computationally efficient intermediate level model for the calibration of the lumped plasticity model for global analysis. In this paper, the first results concerning the detailed modeling level are presented. In particular, the attention is focused on the interaction between the mortar matrix and the embedded composite reinforcement mesh. The mortar is modeled through solid elements, the yarns of the fibre-based mesh with truss elements and the mortar-mesh interaction by means of interface elements. Non-linear static analyses are performed, considering the materials and interfaces non-linearity. The results of previous experimental tests concerning FRM mechanical characterization are considered to calibrate (pull-off tests) and validate (tensile and shear bond tests) the numerical model. The model represents a useful tool to investigate of the FRM optimization, calibrate applicative details and define the behaviour of FRM as homogenized material for the intermediate level modeling.