scholarly journals Double-Leaf Infill Masonry Walls Cyclic In-Plane Behaviour: Experimental and Numerical Investigation

2018 ◽  
Vol 12 (1) ◽  
pp. 35-48 ◽  
Author(s):  
André Furtado ◽  
Hugo Rodrigues ◽  
António Arêde ◽  
Humberto Varum
Keyword(s):  
Reinforced Concrete ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Initial Stiffness ◽  
Seismic Behaviour ◽  
Infill Panels ◽  
Modelling Strategies ◽  
Infill Masonry ◽  
The Individual ◽  
Modelling Approach

Background: The infill masonry walls are widely used in the construction of reinforced concrete buildings for different reasons (partition, thermal and acoustic demands). Since the ‘60s decade, one of the most common typology in the southern Europe was the double-leaf infill walls. Recent earthquake events proved that this specific typology have an important role in the seismic response of reinforced concrete structures in terms of stiffness, strength and failure mechanisms. However, modelling approaches of these specific infill panels cannot be found over the literature. Objective: Due to this, the major goal of the present manuscript is to present a simplified modelling strategy to simulate the double-leaf infill masonry walls seismic behaviour in the software OpenSees. Method: For this, two different modelling strategies were proposed, namely through a global and an individual modelling of the panels. An equivalent double-strut model was assumed and both strategies were compared and calibrated with experimental results from a full-scale in-plane test of a double-leaf infill masonry wall. Results: The numerical results obtained by each strategy are very accurate in terms of prediction of the specimen’ initial stiffness, maximum strength and strength degradation. Conclusion: From the force evolution throughout the tests, it was observed differences lower than 10%. Globally, the individual modelling approach reached better results.

Resistance of Reinforced Concrete Frames with Masonry Infill Walls to In-Plane Vertical Loading

2016 ◽  
Vol 711 ◽  
pp. 982-988
Author(s):  
Alex Brodsky ◽  
David Z. Yankelevsky
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Progressive Collapse ◽  
Lateral Loading ◽  
Masonry Walls ◽  
Reinforced Concrete Frame ◽  
Masonry Infill ◽  
Concrete Frame ◽  
Vertical Loading ◽  
Infill Masonry

Numerous studies have been conducted on the in plane behavior of masonry infill walls to lateral loading simulating earthquake action on buildings. The present study is focused on a problem that has almost not been studied regarding the vertical (opposed to lateral) in-plane action on these walls. This may be of concern when a supporting column of a multi-storey reinforced concrete frame with infill masonry walls undergoes a severe damage due to an extreme loading such as a strong earthquake, car impact or military or terror action in proximity to the column. The loss of the supporting column may cause a fully or partly progressive collapse to a bare reinforced concrete frame, without infill masonry walls. The presence of the infill masonry walls may restrain the process and prevent the development of a progressive collapse. The aim of the present study is to test the in-plane composite action of Reinforced Concrete (RC) frames with infill masonry walls under vertical loading through laboratory experiments and evaluate the contributions of infill masonry walls, in an attempt to examine the infill masonry wall added resistance to the bare frame under these circumstances. Preliminary results of laboratory tests that have been conducted on reinforced concrete infilled frames without a support at their end, under monotonic vertical loading along that column axis will be presented. The observed damages and failure modes under vertical loading are clearly different from the already known failure modes observed in the case of lateral loading.

scholarly journals Analysis of Air Permeability of Insulated Masonry Walls

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2654
Author(s):  
Valdemaras Geležiūnas ◽  
Karolis Banionis ◽  
Raimondas Bliūdžius ◽  
Valdas Paukštys ◽  
Jurga Kumžienė
Keyword(s):  
Air Flow ◽  
Air Permeability ◽  
Masonry Wall ◽  
Mineral Wool ◽  
Masonry Walls ◽  
Standard Methods ◽  
Air Resistance ◽  
Protection Layer ◽  
The Individual ◽  
Flow Resistances

Recently, the construction of external ventilated walls has become popular for public and office buildings. These blocks are used without internal rendering because of their good interior surface, stable dimensions and various filling of masonry joints, which provide an attractive architectural appearance. However, problems with the airtightness of such walls often occur. Currently, there are no standard methods to predict the airtightness of such wall. In practice, samples of particular walls are produced, and their air permeability is measured at laboratories. For the broader use of the results of laboratory air permeability measurements, a methodology has been developed to predict the air permeability of block masonry walls using experimentally determined air flow resistances of the individual layers. The masonry from various blocks were used for the research; mineral wool boards of various air permeability were used for thermal insulation and the wind protection layer. After measuring the air resistance of the samples, the air flow resistances of walls of different construction were calculated. This study compared the calculated and measured air permeability values of different wall masonry samples and evaluated the suitability of created calculation method for prediction of the airtightness of insulated block masonry wall.

scholarly journals Shake Table Response of Unreinforced Masonry and Reinforced Concrete Elements of Special Moment Resisting Frame

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Syed Azmat Ali Shah ◽  
Junaid Shah Khan ◽  
Syed Muhammad Ali ◽  
Khan Shahzada ◽  
Waqar Ahmad ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Shake Table ◽  
Base Excitation ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Moment Resisting

Half-scaled reinforced concrete frame of two storeys and two bays with unreinforced masonry (URM) infill walls was subjected to base excitation on a shake table for seismic performance evaluation. Considering the high seismic hazard Zone IV of Pakistan, reinforcement detailing in the RC frame is provided according to special moment resisting frames (SMFRs) requirement of Building Code of Pakistan Seismic-Provisions (BCP SP-2007). The reinforced concrete frame was infilled with in-plane solid masonry walls in its interior frame, in-plane masonry walls with door and window openings in the exterior frame, out-of-plane solid masonry wall, and masonry wall with door and window openings in its interior frame. For seismic capacity qualification test, the structure was subjected to three runs of unidirectional base excitation with increasing intensity. For system identification, ambient-free vibration tests were performed at different stages of experiment. Seismic performance of brick masonry infill walls in reinforced concrete frame structures was evaluated. During the shake table test, performance of URM infill walls was satisfactory until design ground acceleration was 0.40g with a global drift of 0.23%. The test was continued till 1.24g of base acceleration. This paper presents key findings from the shake table tests, including the qualitative damage observations and quantitative force-displacement, and hysteretic response of the test specimen at different levels of excitation. Experimental results of this test will serve as a benchmark for validation of numerical and analytical models.

Influence of Masonry Infills on the Shear Forces of RC Framed Structures

2016 ◽  
Vol 847 ◽  
pp. 361-368 ◽  
Author(s):  
Daniele Perrone ◽  
Vincenzo Saponaro ◽  
Marianovella Leone ◽  
Maria Antonietta Aiello
Keyword(s):  
Mechanical Properties ◽  
Young Modulus ◽  
Shear Forces ◽  
Seismic Behaviour ◽  
Masonry Infills ◽  
Rc Frames ◽  
Infill Panels ◽  
Rc Framed Structures ◽  
Global And Local ◽  
Modelling Approach

The damages observed during the earthquakes occurred in the last decades have clearly shown as the influence of infill panels on the seismic behaviour of Reinforced Concrete (RC) buildings should be taken into account; the global stiffness and the strength of the RC frames are significantly modified by the infills. In the present study the influence of infills in terms of shear forces has been analyzed by means of linear static analysis; a parametric study has been carried out to evaluate the behavior of infilled frames varying both modelling approach and the mechanical properties of the masonry infills. In terms of modelling approach the single and multi-strut models have been adopted; the Young modulus of masonry infills have been varied in the common range proposed in literature. The results show that multi-strut approach is able to predict both global and local behavior. In addition, the importance of the mechanical properties of masonry infills in the evaluation of the elastic period and shear force in the columns is underlined.

scholarly journals Influence of Chained Masonry on the Seismic Response of Reinforced Concrete Buildings

2021 ◽  
Vol 18 (16) ◽  
Author(s):  
Abdelkader NOUR ◽  
Abdelkader BENANANE ◽  
Humberto VARUM
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Seismic Response ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Reinforced Concrete Buildings ◽  
Seismic Code ◽  
Concrete Buildings ◽  
Finite Element Software ◽  
Algerian Seismic Code

The influence of chained masonry walls, which represents a special case of masonry infill without gap, on the seismic response of reinforced concrete buildings is extremely important due to their wide use in this type of building. We can consider the period of building as the key parameter to study this influence. In this article, we had carried out a comparative study of several 2D models of a multi-storey reinforced concrete building with a brick chained masonry wall using the response spectrum method in the ETABS finite element software, following the prescriptions of the current Algerian seismic code. This study included the use of the number of spans, the span length, the number of storeys, the thickness of the chained masonry wall, the ground soft storey, the openings in the walls, and the short column for studying the influence of these to the walls. The values from the numerical simulation were compared with those from the formula of the period of building, provided by both the Algerian and European codes. Based on the results obtained, we were able to assess the influence of chained masonry walls on the seismic response on this type of buildings. Through this article, we have concluded that these walls have a great influence on the overall behavior of reinforced concrete buildings under seismic loading. HIGHLIGHTS Clarify the importance of numerical simulation of chained masonry walls in the design of reinforced concrete buildings Give recommendations to the current Algerian seismic code for properly design the infilled buildings with chained masonry Know the great danger marked in the current conceptions, which neglect these walls in the phase of conception Give to the infilled reinforced concrete buildings an adequate design in case of earthquake loadings GRAPHICAL ABSTRACT

scholarly journals Experimental Investigation into the Seismic Performance of Fully Grouted Concrete Masonry Walls Using New Prestressing Technology

2019 ◽  
Vol 9 (20) ◽  
pp. 4354 ◽  
Author(s):  
Bin Chi ◽  
Xu Yang ◽  
Fenglai Wang ◽  
Zhiming Zhang ◽  
Yuhu Quan
Keyword(s):  
Seismic Performance ◽  
Rural Areas ◽  
Damping Ratio ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Initial Stiffness ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Concrete Masonry ◽  
Section Type

In recent years, traditional masonry structures have been widely used in rural areas of China. However, they were found to have a poor seismic performance during earthquakes. In this study, a new prestressing technology was proposed and described in detail, and it was used in fully grouted concrete masonry wall systems to improve its seismic performance. The experimental work involved investigating the seismic response of four fully grouted reinforced concrete masonry wall systems, consisting of two symmetrically arranged reinforced block masonry walls, with different section types and prestressing technologies, when subjected to cyclic lateral force. Based on the test results, a flexure and ductile failure occurred in the specimens with a rectangular section, while a shear and brittle failure occurred in the specimens with a T-shape section. The prestressing technology had no significant effect on the failure state of the specimens, but it influenced the crack propagation, making cracks fine and densely covered. A symmetrical and obvious pinching effect was observed in the hysteretic response of all specimens. The average displacement ductility of the specimens varied within a range of values between 3.34 and 6.92, according to the section type of the specimens, and the prestressing technology improved the displacement ductility of the specimens. Moreover, the prestressing technology significantly improved the initial stiffness of the specimens, and the specimens with prestressing technology experienced a greater fall in the degradation of the normalized stiffness than the specimens without this technology throughout the loading process. In addition, the equivalent viscous damping of the specimens ranged between 8.2% and 10.8%, according to the section type. It could be concluded that the prestressing technology improved the energy dissipation of the specimens at the ascending stage, although it had no marked influence on the equivalent damping ratio of the specimens.

Numerical Simulation of Masonry Walls Retrofitted by Prefabricated Reinforced Concrete Panels

2013 ◽  
Vol 351-352 ◽  
pp. 1514-1518
Author(s):  
Yong Qun Zhang ◽  
Tao Wang
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Force Transmission ◽  
Nonlinear Analyses ◽  
Concrete Panels ◽  
Seismic Design Code ◽  
Cast Concrete ◽  
Assembly Technology

Assembly technology using prefabricated reinforced concrete (RC) members can effectively improve the seismic performance of existing masonry buildings. In this study, an existing masonry wall is enhanced by two pieces of prefabricated RC panels bonded on both surfaces of the wall. In order to guarantee the co-action between RC panels and the masonry wall, three techniques are employed, specifically, RC dowelling keys, grouting agent, and post-cast concrete bands. To investigate the interaction and force transmission between the two components, this study builds sophisticated finite element models and conducts nonlinear analyses to simulate the quasi-static cyclic tests. It is demonstrated that the proposed retrofitting technology effectively improves the seismic performance of existing masonry walls. The strength of existing walls increases 3-4 times and the stiffness increases 2-3 times, so that the requirement of current seismic design code is satisfied.

scholarly journals Recent Findings and Open Issues concerning the Seismic Behaviour of Masonry Infill Walls in RC Buildings

2020 ◽  
Vol 2020 ◽  
pp. 1-20 ◽  
Author(s):  
André Furtado ◽  
Maria Teresa de Risi
Keyword(s):  
Reinforced Concrete ◽  
Risk Mitigation ◽  
Concrete Structures ◽  
Mitigation Measures ◽  
Economic Losses ◽  
Reinforced Concrete Structures ◽  
Seismic Behaviour ◽  
Infill Walls ◽  
Modelling Strategies ◽  
Open Issues

The extension of the damages observed after the last major earthquakes shows that the seismic risk mitigation of infilled reinforced concrete structures is a paramount topic in seismic prone regions. In the assessment of existing structures and the design of new ones, the infill walls are considered as nonstructural elements by most of the seismic codes and, generally, comprehensive provisions for practitioners are missing. However, nowadays, it is well recognized by the community the importance of the infills in the seismic behaviour of the reinforced concrete structures. Accurate modelling strategies and appropriate seismic assessment methodologies are crucial to understand the behaviour of existing buildings and to develop efficient and appropriate mitigation measures to prevent high level of damages, casualties, and economic losses. The development of effective strengthening solutions to improve the infill seismic behaviour and proper analytical formulations that could help design engineers are still open issues, among others, on this topic. The main aim of this paper is to provide a state-of-the-art review concerning the typologies of damages observed in the last earthquakes where the causes and possible solutions are discussed. After that, a review of in-plane and out-of-plane testing campaigns from the literature on infilled reinforced concrete frames are presented as well as their relevant findings. The most common strengthening solutions to improve the seismic behaviour are presented, and some examples are discussed. Finally, a brief summary of the modelling strategies available in the literature is presented.

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