Diagonal compression tests on masonry walls strengthened with a GFRP mesh reinforced mortar coating

Abstract The evaluation of structural safety derives from the knowledge of material properties. In case of existent masonry building, the definition of reliable mechanical parameters could be a very difficult task to be achieved. For this reason, an estimation of these values is useful, for example it is the first phase of the knowledge process, for simplified mechanical model or when NTD test is the only possibility.The transversal connection in masonry panels is a technological detail that affects the static and seismic behavior and could significantly increase the strength of the element.In this paper the effect of transversal connection in double-leaf brickwork masonry panels is evaluated by diagonal compression tests. To achieve this goal, a new set-up was designed to load each leaf independently.The results have shown an increment of about 20% in strength if transversal connection is present. If the leaves have very different mechanical parameters, the tests highlight an unexpected behavior.

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FRCM Strengthened Masonry Panels: The Role of Mechanical Anchorages and Symmetric Layouts

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.747.334 ◽

2017 ◽

Vol 747 ◽

pp. 334-341 ◽

Cited By ~ 6

Author(s):

Francesca Ferretti ◽

Andrea Incerti ◽

Barbara Ferracuti ◽

Claudio Mazzotti

Keyword(s):

Masonry Walls ◽

Fiber Reinforced ◽

Compression Tests ◽

Fiber Reinforced Composite ◽

Single Leaf ◽

Reinforced Composite ◽

Experimental Campaign ◽

Diagonal Compression ◽

Strength And Ductility

The use of fiber reinforced composite materials for the retrofitting of existing masonry buildings is investigated in this paper. Indeed, they represent a great alternative to traditional strengthening techniques for the improvement of the seismic performance of masonry walls. Focusing on the in-plane behavior of masonry, an experimental campaign is here presented with the objective of studying the efficiency of different strengthening solutions. Diagonal compression tests were conducted on single-leaf masonry panels reinforced with Fiber Reinforced Cementitious Matrix (FRCM) using different fibers typologies and layouts. Glass or carbon fiber grids embedded in a lime-based mortar matrix were applied on one or both sides of masonry panels, with or without mechanical anchorages. The comparison of the different strengthening techniques is analyzed in terms of failure mode, strength and ductility. The results are then discussed considering the provisions and design formula proposed for FRP strengthening by the Italian CNR Guidelines.

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Destructive Tests for the Determination of Masonry Performance

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.417-418.753 ◽

2009 ◽

Vol 417-418 ◽

pp. 753-756

Author(s):

Lucio Nobile ◽

Cristina Gentilini ◽

Veronica Bartolomeo ◽

Mario Bonagura

Keyword(s):

Mechanical Properties ◽

Experimental Research ◽

State Of The Art ◽

The State ◽

Masonry Walls ◽

Compression Tests ◽

Diagonal Compression

Several masonry panels are studied by means of destructive tests such as compressive, diagonal compression and shear-compression tests. The experimental research allows to characterize the mechanical properties of masonry walls in order to assess the masonry performance. Moreover, a brief recall of the most important experimental progress is presented in order to understand the state of the art of the research in the field of destructive tests.

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Comparison of In-Plane Mechanical Performances of Masonry Walls Strengthened with Different Mortar Coatings Reinforced with Glass or Carbon Fiber Composite Meshes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.747.289 ◽

2017 ◽

Vol 747 ◽

pp. 289-297 ◽

Cited By ~ 1

Author(s):

Natalino Gattesco ◽

Ingrid Boem

Keyword(s):

Carbon Fibers ◽

Coating Layer ◽

Fiber Composite ◽

Shear Stiffness ◽

Masonry Walls ◽

Compression Tests ◽

Carbon Fiber Composite ◽

Diagonal Compression ◽

Mechanical Performances ◽

Compression Resistance

The results of some diagonal compression tests performed on solid brick masonry samples (1160x1160x250 mm3) to evaluate and compare the effectiveness of different shear reinforcement techniques for existing masonry based of the application, on both sides of the wall, of a mortar coating layer reinforced with fiber composite meshes are presented and discussed in the paper. In particular, 30 mm and 10 mm thick mortar coatings, made of three different mortar types and reinforced by means of both glass and carbon-fibers composite meshes were considered. Significant resistance increases (about 110%) were attained in respect to plain masonry; moreover, it emerged that the meshes are able to prevent the masonry brittle collapse, absorbing tensile stresses in the cracked areas. By maintaining constant the coating thickness, better mortar characteristics determined an increase of the resistance increment ratio but a more rapid decrease of resistance after peak. Similar performances were attained by samples characterized by approximately constant values of shear stiffness and diagonal compression resistance. The differences attributable to the different type of meshes resulted minimal, due to the similar reinforcement percentage.

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Shear Capacity of Masonry Panels Reinforced with Inorganic Strengthening Systems

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.817.486 ◽

2019 ◽

Vol 817 ◽

pp. 486-492

Author(s):

Marta Del Zoppo ◽

Gennaro Maddaloni ◽

Alberto Balsamo ◽

Marco di Ludovico ◽

Andrea Prota

Keyword(s):

Composite Materials ◽

Shear Capacity ◽

Masonry Walls ◽

Masonry Buildings ◽

Compression Tests ◽

Plane Shear ◽

Diagonal Compression ◽

The University ◽

Fabric Reinforced Cementitious Matrix ◽

Inorganic Composite

Unreinforced masonry buildings are particularly vulnerable to brittle failures during seismic events due to the poor in-plane shear capacity of masonry walls. The use of strengthening solutions with polymeric matrices is not often recommended for masonry buildings, due to breathability issues, and the adoption of inorganic matrices is sometimes considered preferable. In this paper, the use of inorganic composite materials for improving the in-plane shear capacity of tuff masonry walls is investigated. The experimental data from 83 diagonal compression tests carried out at the University of Naples Federico II in recent years have been collected and the main results are herein discussed to outline the main features of different strengthening techniques with inorganic composite materials such as Reinforced Plaster (RP), Composite Reinforced Mortar (CRM) and Fabric Reinforced Cementitious Matrix (FRCM).

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Comparison between Design Formulations and Numerical Results for In-Plane FRCM-Strengthened Masonry Walls

Applied Sciences ◽

10.3390/app10144998 ◽

2020 ◽

Vol 10 (14) ◽

pp. 4998 ◽

Cited By ~ 2

Author(s):

Giovanni Crisci ◽

Francesca Ceroni ◽

Gian Piero Lignola

Keyword(s):

Shear Strength ◽

Shear Force ◽

Structural Engineering ◽

Numerical Results ◽

Masonry Walls ◽

Fiber Reinforced ◽

Compression Tests ◽

Diagonal Compression ◽

Externally Bonded ◽

Strengthening Technique

Strengthening strategies and structural rehabilitation of existing buildings with innovative materials and techniques are today one of the main activities in the field of structural engineering. Externally bonded Fiber Reinforced Cementitious Matrix (FRCM), materials are spreading as an alternative strengthening technique to the more traditional Fiber Reinforced Polymer (FRP) ones, especially for masonry elements. This research focuses on the assessment of the shear strength of in-plane FRCM-strengthened masonry walls by means of code predictions and numerical results, with particular attention on the interpretation of diagonal compression tests simulated by means of Finite Element (FE) models. Firstly, the various approaches commonly adopted for the interpretation of diagonal compression tests in terms of shear strength were examined, since codes give generally provisions in terms of maximum shear force, while several experimental and numerical results of diagonal compression tests are available in literature. Then, the numerical simulations of diagonal compression tests obtained by several FE analyses in a previous work were examined in light of these different approaches; the corresponding predictions of the shear force are compared with code indications in order to individuate the most reliable approach both for the un-strengthened and the FRCM-strengthened walls. For the latter ones, a detailed analysis of the actual strain levels in the reinforcement was carried out, too, by means of FE analysis.

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In-plane Shear Strengthening of Unreinforced Masonry Walls Using GFRP Jacketing

Periodica Polytechnica Civil Engineering ◽

10.3311/ppci.11311 ◽

2017 ◽

Cited By ~ 2

Author(s):

Enea Mustafaraj ◽

Yavuz Yardim

Keyword(s):

Experimental Results ◽

Test Results ◽

Compression Tests ◽

Shear Strengthening ◽

Plane Shear ◽

Standard Size ◽

Reinforced Polymer ◽

Glass Fiber Reinforced ◽

Diagonal Compression ◽

Before And After

In this paper, it is presented the experimental results of a campaign on diagonal compression tests, as of ASTM E519-02, to assess and compare the in-plane behavior of standard size of 1200 × 1200 × 250 mm, for three unreinforced and three reinforced wall panels by glass fiber reinforced polymer (GFRP) embedded in an inorganic matrix.From the diagonal compression test results, were determined some of the main mechanical parameters such as: shear strength, modulus of rigidity and ductility, before and after application of the reinforcement.The experimental results showed that the GFRP reinforced panels exhibited a significant increase of 127% in shear resistance, 1100% in ductility and 650% in modulus of rigidity when compared to unreinforced panels.It was concluded that this technique provided satisfactory results and can be considered a suitable method for repair of masonry structures.

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Mechanical characterization of concrete block used on infill masonry panels

International Journal of Structural Integrity ◽

10.1108/ijsi-05-2017-0030 ◽

2018 ◽

Vol 9 (3) ◽

pp. 281-295 ◽

Cited By ~ 2

Author(s):

Patricia Raposo ◽

André Furtado ◽

António Arêde ◽

Humberto Varum ◽

Hugo Rodrigues

Keyword(s):

Mechanical Characterization ◽

Experimental Tests ◽

Concrete Block ◽

Masonry Walls ◽

Compression Tests ◽

Content Type ◽

Average Resistance ◽

Concrete Blocks ◽

Simple Compression ◽

Infill Masonry

Purpose The infill masonry walls in recent worldwide earthquakes have shown that it is necessary to conduct further studies to characterize the behavior of existing buildings and, in particular, of infill masonry walls under seismic activity. The lack of characterization studies of infill walls made by concrete blocks justifies the investigation reported herein, which includes experimental tests on sample sets to evaluate the mechanical properties of masonry components (units and mortar) and assemblages (wallets) made with masonry units from Faial. For the later, normal compressive, diagonal tensile/shear and out-of-plane flexural strengths were obtained according to standard procedures, the results of which are presented in the manuscript. The paper aims to discuss these issues. Design/methodology/approach One experimental campaign was conducted with the aim to mechanically characterize concrete blocks masonry samples. Several experimental tests were carried out in full-scale masonry concrete wallets according to the constructive methodology used. Findings Based on the data obtained from the mechanical characterization tests of the concrete masonry blocks, it can be seen that under simple compression, the masonry specimens’ average resistance is about 6 times superior than the average resistance to diagonal shear/tension, while the stiffness is almost doubled. In simple compression tests, it was observed that the masonry specimens cracked in areas of higher drilling of the blocks. In the tensile tests by diagonal compression, it was found that the test specimens were mainly fissured by the block/mortar joint interfaces, following the delineation of settlement and top joints. Originality/value There are no experimental results available in the literature for this type of bricks that can contribute to the development of numerical studies.

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Diagonal Compression of Masonry Walls Strengthened with Composite Reinforced Mortar

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.817.528 ◽

2019 ◽

Vol 817 ◽

pp. 528-535 ◽

Cited By ~ 1

Author(s):

Tommaso D'Antino ◽

Francesca Giulia Carozzi ◽

Carlo Poggi

Keyword(s):

Weight Ratio ◽

High Strength ◽

Organic Matrix ◽

Masonry Walls ◽

Matrix Composites ◽

The North ◽

Crm System ◽

Diagonal Compression ◽

Promising Solution ◽

Inorganic Matrix

The use of inorganic matrix composites to strengthen and retrofit existing masonry and concrete structures has been gaining increasing interest in the last years. Among them, composite reinforced mortar (CRM) systems are a promising solution to increase the shear and flexural capacity of masonry panels. CRMs are comprised of a relatively thin inorganic matrix layer reinforced with a bi-dimensional grid made with high-strength fibers impregnated with an organic matrix. They are compatible with the substrate due to the use of inorganic matrix, have good durability and high-strength-to weight ratio due to the use of reinforcing composite materials. CRM systems are still in their infancy and limited research is available in the literature. In this paper, masonry walls constructed with historical bricks typical of the north of Italy were strengthened with a CRM system including a glass composite grid and a lime-based mortar and were subjected to diagonal compression. Three walls were strengthened with the CRM and one was used as a control specimen. The results obtained showed that the CRM system significantly increased the shear strength of the masonry panels subjected to diagonal compression.

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Grout Injection Effect on the Shear Behavior of FRCM Strengthened Stone Masonry Panels

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.817.552 ◽

2019 ◽

Vol 817 ◽

pp. 552-559

Author(s):

Francesca Ferretti ◽

Andrea Incerti ◽

Anna Rosa Tilocca ◽

Claudio Mazzotti

Keyword(s):

Shear Capacity ◽

Stone Masonry ◽

Masonry Structures ◽

Compression Tests ◽

Grout Injection ◽

Structural Element ◽

Diagonal Compression ◽

Two Samples ◽

Injection Effect

During the last decades, several seismic phenomena have shown the high vulnerability of existing stone masonry structures subject to horizontal actions. Innovative composite materials, such as Fiber Reinforced Cementitious Matrix (FRCM), can be adopted for the retrofitting of masonry structures. The use of these innovative FRCM systems is usually combined with a more traditional retrofitting technique: grout injection. It allows to restore or improve the transversal connection between wall leaves, ensuring a monolithic behavior of the structural element. The objective of this research was to analyze the effect of the quality of the grout injection on the shear response of FRCM strengthened stone masonry panels. Results from an experimental campaign, where stone masonry specimens were subject to diagonal compression tests, are therefore presented in this paper. Two samples were subject to grout injection and one of them was strengthened with Steel Reinforced Grout (SRG). Comparisons between the experimental results showed that grout injection alone, if correctly executed, could determine a significant improvement in the shear capacity of masonry panels. The application of the FRCM strengthening system could further enhance the behavior of the samples, especially influencing the failure mode. Comparisons with analytical formulations for the evaluation of the capacity of strengthened walls are also presented.

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