scholarly journals Experimental Examination of Hollow Brick Masonry Wall with Reinforcement

2019 ◽  
Vol 8 (4) ◽  
pp. 4680-4684 ◽  
Keyword(s):  
Shear Walls ◽  
Unreinforced Masonry ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Masonry Building ◽  
Brick Wall ◽  
High Wind ◽  
Load Bearing ◽  
Reinforced Masonry ◽  
Hollow Brick

The research aims at conducting a quality research with Reinforcement of a hollow brick wall. The empty internal sections significantly lower the dead load. With a better surface finish, the side of the block was cast, minimizing the cost of plastering. Several sample mixes are tested to achieve a finished surface. The respective frames were cast with and without reinforcement and the test results were compared. The blocks were used to build masonry walls and ' load-bearing strength ' of the walls was tested. It is possible to use the reinforced hollow block as a load-bearing wall. Nearly 75 percent of the deaths related to the earthquake in the last century,Buildings have collapsed, the majority of which (more than 70 percent)is due to the collapse of buildings made of masonry. Most of the properties in India are Unreinforced Masonry (URM) buildings that are weak and vulnerable even under moderate earthquakes and that function on the wall due to high wind forces, causing severe damage to high wind loads and it is recognized that Reinforced Masonry Building has many advantages over unreinforced masonry building.The use was very limited in Indian building practices and there are still no approved codes and shear walls were used in most constructions, even in mild earthquakes, instead of reinforced masonry walls

Experimental Investigation on Masonry with Textile Reinforcement in Thin Bed Joints

2019 ◽  
Vol 817 ◽  
pp. 404-411 ◽  
Author(s):  
Dorothea Saenger ◽  
Michael Raupach
Keyword(s):  
Earth Pressure ◽  
Masonry Wall ◽  
Masonry Building ◽  
Lateral Loads ◽  
Research Project ◽  
Ongoing Research ◽  
Load Bearing ◽  
Flexural Tensile Strength ◽  
Reinforced Masonry ◽  
Building Components

The application of textile reinforcement can help to increase the load-bearing capacity of masonry building components, especially those subjected to lateral loads caused by wind, earth pressure or earthquake. The reinforcement can be applied externally or be integrated in the bed joint. The key part of an ongoing research project is to investigate the bonding and load-bearing behavior of masonry building components reinforced with textile in thin bed joints with the aim to develop reinforcing elements. With these reinforcing elements for bed joints the construction of basements and higher buildings will be more attractive with masonry. In the first part of the project, the relevant material and bond properties of preselected materials were determined, and a suitable textile was selected. In the second part, four-point bending tests on unreinforced and reinforced masonry wall specimens were carried out in order to investigate the effectiveness of bed joint textile reinforcement to increase the masonry flexural tensile strength. In the third part, a proposal for the design of prototypical reinforcing elements will be worked out. This paper deals with the two first parts of the research project.

scholarly journals Numerical Modeling of Unreinforced Masonry Walls Strengthened with Fe-Based Shape Memory Alloy Strips

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2961
Author(s):  
Moein Rezapour ◽  
Mehdi Ghassemieh ◽  
Masoud Motavalli ◽  
Moslem Shahverdi
Keyword(s):  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Unreinforced Masonry ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Vertical Strip ◽  
Maximum Resistance ◽  
The Cross ◽  
Post Tensioning

This study presents a new way to improve masonry wall behavior. Masonry structures comprise a significant part of the world’s structures. These structures are very vulnerable to earthquakes, and their performances need to be improved. One way to enhance the performances of such types of structures is the use of post-tensioning reinforcements. In the current study, the effects of shape memory alloy as post-tensioning reinforcements on originally unreinforced masonry walls were investigated using finite element simulations in Abaqus. The developed models were validated based on experimental results in the literature. Iron-based shape memory alloy strips were installed on masonry walls by three different configurations, namely in cross or vertical forms. Seven macroscopic masonry walls were modeled in Abaqus software and were subjected to cyclic loading protocol. Parameters such as stiffness, strength, durability, and energy dissipation of these models were then compared. According to the results, the Fe-based strips increased the strength, stiffness, and energy dissipation capacity. So that in the vertical-strip walls, the stiffness increases by 98.1%, and in the cross-strip model's position, the stiffness increases by 127.9%. In the vertical-strip model, the maximum resistance is equal to 108 kN, while in the end cycle, this number is reduced by almost half and reaches 40 kN, in the cross-strip model, the maximum resistance is equal to 104 kN, and in the final cycle, this number decreases by only 13.5% and reaches 90 kN. The scattering of Fe-based strips plays an important role in energy dissipation. Based on the observed behaviors, the greater the scattering, the higher the energy dissipation. The increase was more visible in the walls with the configuration of the crossed Fe-based strips.

Analytical modeling of masonry load-bearing walls

2003 ◽  
Vol 30 (5) ◽  
pp. 795-806 ◽  
Author(s):  
Yi Liu ◽  
J L Dawe
Keyword(s):  
Flexural Rigidity ◽  
Computer Application ◽  
Masonry Walls ◽  
Load Bearing ◽  
Analytical Technique ◽  
Reinforced Masonry ◽  
Material Stiffness ◽  
The Moment ◽  
Magnification Effect

An analytical technique was developed and encoded for computer application to study the behaviour of concrete masonry load-bearing walls under various loading conditions. Both geometrical and material nonlinearities to account for the moment magnification effect and the degradation of material stiffness are included in the development. Effects of vertical reinforcing steel, masonry tensile cracking, and compressive crushing are included directly in the moment–curvature relationship, which is used in the determination of element stiffnesses at successive load increments. A parametric study was conducted following verification of the analytical model by comparing results with experimental test data. Effective flexural rigidity (EIeff) values at failure were obtained analytically and compared with values suggested in the Canadian masonry code CSA-S304.1-M94. It was concluded that CSA-S304.1-M94 tends to underestimate EIeff values for reinforced walls and thus leads to a conservative design over a range of parameters. Based on approximately 500 computer model tests, a lower bound bilinear limit for the effective rigidity of reinforced masonry walls was established. This limit is believed to provide an accurate and realistic estimate of EIeff.Key words: walls, load bearing, masonry, analytical, nonlinear, rigidity, stress–strain, moment–curvature.

scholarly journals Experimental and Numerical Study of Behaviour of Reinforced Masonry Walls with NSM CFRP Strips Subjected to Combined Loads

Buildings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 103
Author(s):  
Houria Hernoune ◽  
Benchaa Benabed ◽  
Antonios Kanellopoulos ◽  
Alaa Hussein Al-Zuhairi ◽  
Abdelhamid Guettala
Keyword(s):  
Failure Modes ◽  
Numerical Study ◽  
Masonry Wall ◽  
Brick Masonry ◽  
Masonry Walls ◽  
Near Surface ◽  
Combined Loads ◽  
Reinforced Masonry ◽  
Brick And Mortar ◽  
Near Surface Mounted

Near surface mounted (NSM) carbon fibers reinforced polymer (CFRP) reinforcement is one of the techniques for reinforcing masonry structures and is considered to provide significant advantages. This paper is composed of two parts. The first part presents the experimental study of brick masonry walls reinforced with NSM CFRP strips under combined shear-compression loads. Masonry walls have been tested under vertical compression, with different bed joint orientations 90° and 45° relative to the loading direction. Different reinforcement orientations were used including vertical, horizontal, and a combination of both sides of the wall. The second part of this paper comprises a numerical analysis of unreinforced brick masonry (URM) walls using the detailed micro-modelling approach (DMM) by means of ABAQUS software. In this analysis, the non-linearity behavior of brick and mortar was simulated using the concrete damaged plasticity (CDP) constitutive laws. The results proved that the application of the NSM-CFRP strips on the masonry wall influences significantly strength, ductility, and post-peak behavior, as well as changing the failure modes. The adopted DMM model provides a good interface to predict the post peak behavior and failure mode of unreinforced brick masonry walls.

scholarly journals Behaviour of reinforced masonry shear walls under cyclic loading

1971 ◽  
Vol 4 (2) ◽  
pp. 316-330 ◽  
Author(s):  
J. C. Scrivener ◽  
D. Williams
Keyword(s):  
Hysteresis Loops ◽  
Shear Walls ◽  
Concrete Block ◽  
Maximum Load ◽  
Masonry Walls ◽  
Aspect Ratios ◽  
Reinforced Masonry ◽  
Dynamic Analyses ◽  
Bearing Loads ◽  
Constant Deformation

A series of tests on reinforced brick and concrete block walls subjected to cyclic static loading applied in the plane of the walls is described. The parameters varied were the magnitude of bearing loads, wall aspect ratios and reinforcing percentages and distribution. The hysteresis loops from several cycles of load-deflection obtained by cycling at constant deformation, normally a multiple of the deformation at maximum load, were obtained and the walls loaded to failure. In particular, the ductility capability, stiffness degradation, load deterioration and the ductility requirements as determined by dynamic analyses are discussed in relation to the aseismic design of load bearing masonry walls.

scholarly journals Evaluation Of Shear Capacity For Brick Masonry Walls

2015 ◽  
Vol 5 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Eva Partene ◽  
Luminita Fekete-Nagy ◽  
V. Stoian
Keyword(s):  
Residential Buildings ◽  
Concrete Columns ◽  
Unreinforced Masonry ◽  
Shear Capacity ◽  
Experimental Program ◽  
Masonry Walls ◽  
Common System ◽  
Vertical Loading ◽  
Reinforced Masonry ◽  
Ceramic Blocks

Abstract The papers presents the results of an experimental program and provides valuable information regarding the behaviour of structural masonry walls built up using ceramic blocks with hollows, which represents a very common system for low-rise residential buildings, up to 4 stories, depending on the seismic acceleration on site. A number of six masonry walls where tested in bear state being subjected to constant vertical loading and to cyclic in-plane horizontal loads. The main objective was to determine the shear capacity for unreinforced masonry walls and reinforced masonry walls. The experimental results were also useful to determine the contribution of the reinforcing of the masonry walls with concrete columns. The comparison between unreinforced masonry and reinforced masonry has a great importance due to the fact that the Romanian Seismic Standards have imposed the reinforcement in seismic areas for building with more than 1 storey. Further studies will be conducted on strengthening the masonry walls using FRP materials.

Numerical Evaluation of Mechanical Parameters Role in GFRP Strengthened Cobblestone Masonry Walls

2017 ◽  
Vol 747 ◽  
pp. 504-511
Author(s):  
Natalino Gattesco ◽  
Alessandra Gubana ◽  
Massimo Melotto
Keyword(s):  
Parametric Study ◽  
Peak Load ◽  
Element Model ◽  
Masonry Wall ◽  
Fiber Reinforced Polymers ◽  
Masonry Walls ◽  
Glass Fiber Reinforced ◽  
Reinforced Masonry ◽  
Smeared Crack Approach ◽  
Smeared Crack

The use of a GFRP (Glass Fiber Reinforced Polymers) mesh, embedded as a reinforcement in a mortar coating on both wall sides, proved to be effective and reliable in increasing the masonry wall resistance and the plastic deformation capacity.In this study, a NL finite element model, developed to predict the in-plane behaviour of masonry walls strengthened by means of this technique, is refined and used in an extensive parametric study. Numerical results were compared with diagonal compression test data on URM and RM cobblestone masonry samples, showing good agreement. The masonry panel and the mortar coating were modelled as isotropic homogeneous materials with a smeared crack approach, whereas the GFRP reinforcement was modelled as a mesh of truss elements. Properties assigned to materials were derived from experimental tests.The parametric study performed before on some involved mechanical properties, considering a standard range of variation, is now extended to other parameters. Moreover, the combined variation of different properties is considered. The actual contribute of each component (masonry, GFRP mesh, mortar) on some macroscopic parameters (strength and ductility of the specimen) is evaluated.The parametric analysis highlights the important role of the GFRP mesh not only on the peak load increment but also on the post-peak behavior and, in particularly, on the ductility increment of the reinforced masonry panel. These results can address the optimization of the intervention technique and the deliverable of operative guidelines for practitioners.

Strengthening of Historic Masonry Structures with Composite Materials

2017 ◽  
pp. 613-647 ◽  
Author(s):  
Marco Corradi ◽  
Adelaja Israel Osofero ◽  
Antonio Borri ◽  
Giulio Castori
Keyword(s):  
Composite Materials ◽  
Stone Masonry ◽  
Masonry Walls ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Historic Masonry ◽  
Reinforced Masonry ◽  
Total Lack ◽  
Recent Earthquakes ◽  
Masonry Vaults

Existing un-reinforced masonry buildings made of vaults, columns and brick and multi-leaf stone masonry walls, many of which have historical and cultural importance, constitute a significant portion of construction heritage in Europe and rest of the world. Recent earthquakes in southern Europe have shown the vulnerability of un-reinforced masonry constructions due to masonry almost total lack of tensile resistance. Composite materials offer promising retrofitting possibilities for masonry buildings and present several well-known advantages over existing conventional techniques. The aim of this work is to analyze the effectiveness of seismic-upgrading methods both on un-damaged (preventive reinforcement) and damaged (repair) masonry building. After a brief description of mechanical and physical properties of composite materials, three different applications have been addressed: in-plane reinforcement of masonry walls, extrados and intrados reinforcement of masonry vaults/arches and masonry column confinement with composite materials.

Analysis of safety of slender concrete masonry walls in relation to CSA S304-14

2019 ◽  
Vol 46 (5) ◽  
pp. 424-438
Author(s):  
Andrea C. Isfeld ◽  
Anna Louisa Müller ◽  
Mark Hagel ◽  
Nigel G. Shrive
Keyword(s):  
Concrete Block ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Effective Height ◽  
Design Standard ◽  
Euler Buckling ◽  
Concrete Masonry ◽  
Reinforced Masonry ◽  
Out Of Plane ◽  
Support Conditions

The Canadian masonry design standard appears to be overly conservative in determining the capacity of concrete block walls with slenderness ratios greater than 30. When assessing the potential for buckling of a masonry wall according to Euler buckling criteria, the effective height is determined in part from the end supports. In Euler theory only pinned, fixed and free support conditions are considered, and the Canadian standard considers the support conditions to be hinged, elastic or stiff. For a partially reinforced masonry wall a true hinged base support is expected to be difficult to achieve, as the width of the concrete block restrains rotation. The effect of the base support conditions on the deflected shape of partially grouted block walls was investigated under axial and out-of-plane loading. The results of this testing were compared with calculations based on the Canadian masonry standard. It becomes clear that the standard is overly conservative in many cases and the design of slender walls needs to be re-examined.

Out-of-Plane Behavior of Masonry Walls Strengthened with Ferrocement

2010 ◽  
Vol 163-167 ◽  
pp. 3545-3550 ◽  
Author(s):  
Sheng Ping Chen
Keyword(s):  
Volume Fraction ◽  
Load Capacity ◽  
Experimental Studies ◽  
Material Model ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Ultimate Load Capacity ◽  
Softening Behavior ◽  
Reinforced Masonry ◽  
Out Of Plane

Un-reinforced masonry (URM) structures may fail and collapse under out-of-plane loads generated by seismic forces or explosions. Adding a ferrocement overlay onto the URM walls is an effective solution in increasing the ultimate load capacity and ductility. This paper deals with the numerical and experimental studies on the out-of-plane behavior of un-reinforced masonry walls strengthened with ferrocement. The material parameters considered are the volume fraction of reinforcement and the loading area. A numerical model was proposed to simulate the experimental results. The employed material model for masonry wall is based on the theory of Drucker-Prager plasticity taking into account the tension softening behavior, while the ferrocement is modeled as a composite material with linear strain hardening followed by ideal plasticity. The proposed model simulates the load-deflection behavior of the strengthened wall well.

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