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Featured Application: The system under study will provide a modification of the classic use of exoskeletons installed outside buildings on their facades. The lightweight intervention technique will act as an integrated retrofit system of existing RC and masonry buildings by improving both the seismic performance and the energy efficiency with a negligible increase in the mass, a satisfactory augmentation of the stiffness and a reasonable reduction in the thermal dispersion through the structure envelope. The awareness of the vulnerability of existing structures under both seismic and energy perspectives highlights the need for integrated retrofit solutions that combine structural and thermal enhancements. From this perspective, this study explored the efficacy of the Resisto 5.9 Tube system, which is a seismic retrofit solution for masonry and reinforced concrete (RC) structures that also improves the energy performance by integrating a thermal coat integrated within its basic steel framework. This research involved application to a RC building of a design procedure specifically developed for this system that was aimed at facilitating its adoption by designers involved in seismic retrofitting analysis. After designing the system components, nonlinear static analyses were performed using finite element software to compare the building's seismic performance before and after the application of the Resisto 5.9 Tube. The results demonstrate a significant increase in the seismic safety coefficient ζE from 0.26 to 0.42, which proved the potential of this intervention to enhance the seismic safety of existing RC buildings. [ABSTRACT FROM AUTHOR]

In this study, a masonry panel under a high compressive stress to strength ratio is considered. The panel is modeled as a composite structure by considering a repeated unit cell of mortar and brick. Load redistributions due to creep in mortar and brick as composite materials are accounted for. A step-by-step in-time analysis is performed to calculate the load redistribution in the composite masonry. Time-dependent system reliability analysis of the masonry panel is performed by defining the component and system limit state functions at each time step. While the reliability index of ductile materials depends on the load level in each part of masonry, the reliability index of brittle materials depends only on the overall load. By proposing the reliability index of quasi-brittle materials being between these two reliability index bounds, the reliability index of quasi-brittle materials depends on both the load level in each part and the overall load. Using the proposed reliability index of quasi-brittle materials, partial safety factors for masonry panel design considering creep and damage are calibrated based on the Hasofer and Lind method. A design example using the proposed partial safety factor is presented. [ABSTRACT FROM AUTHOR]

This paper presents an in-depth analysis of the Kopčić House, a significant example of modernist architecture in Sarajevo, Bosnia and Herzegovina, focusing on its structural-specific features and seismic performance. The Kopčić House embodies a confined masonry structure with innovative construction features, combining load-bearing masonry walls with reinforced concrete elements. This architectural approach was pioneering for its time, combining traditional construction methods with innovative materials and techniques. Detailed analysis using numerical modeling techniques, specifically 3D modeling with the 3Muri software (Vers.14.2.0.4), was conducted to assess the seismic resilience of the structure. The analysis considered different load distributions and eccentricities to comprehensively evaluate the building's response to lateral forces. The findings of this research reveal the structural capacity and potential vulnerabilities of the Kopčić House when subjected to seismic events. While the building demonstrates inherent strength due to its confined masonry design, areas requiring structural strengthening were identified through numerical simulations. This study contributes to the broader understanding of confined masonry construction within the context of modernist architecture. By integrating historical research with advanced structural analysis, this work aims to bridge the gap between architectural heritage and contemporary engineering practices. [ABSTRACT FROM AUTHOR]

An orthotropic homogenized model is used to investigate the in-plane elastic behavior of coated masonry walls. The homogenization process mainly consists of modeling the elementary cell of a three-layer medium by using suitable designed assemblies of in-parallel springs. On the basis of the latter, the stresses distributed between masonry and reinforcement coatings are analytically assessed after the determination of the average stress acting on the homogeneous medium. The precision of the theoretical outcomes is evaluated through comparisons with finite element (FE) models. Static and dynamic numerical analyses are carried out on both non-homogeneous and homogeneous FE models of sample systems. The homogeneous model is observed to adequately capture both the local and global behavior of reinforced masonry walls. Parametric analyses are also performed to investigate the effectiveness of reinforcement on the overall behavior of the system. [ABSTRACT FROM AUTHOR]

The north of the state of Baja California (BC) is located in one of the regions of Mexico with a high seismic risk. The predominant infrastructure in the city of Tijuana consists of reinforced masonry housing structures, making it crucial to understand the dynamic behavior of this type of structure. Using the "Vulnerability Modeller'sToolKit" (VMTK), fragility functions were obtained for low, medium, and high levels of seismic design. It was found that the probability of achieving or surpassing the different damage states (light, moderate, extensive, and complete) is high in low-height housing (1–3 floors) for an expected value of 0.50 g of PGA and in medium-height housing (4–7 floors) for an expected value of 0.5 g of SA (T = 0.5 s).Vulnerability functions were derived, and it was determined that, for a low seismic design level, low-height and medium-height structures, respectively presented loss probability rates of 30% and 44% for an expected value of 0.50 g of PGA and SA (T = 0.5 s). These fragility and vulnerability functions can be used to estimate damage and losses in future risk scenarios, thereby reducing uncertainty in the risk analysis calculations for the city of Tijuana. [ABSTRACT FROM AUTHOR]

The brittle failure of unreinforced masonry (URM) walls when subjected to in-plane loads present low shear strength remains a critical issue. The investigation presented in this paper touches on the retrofitting of URM structures with textile-reinforced mortar (TRM), which enables shifting the shear failure mode from a brittle to a pseudo-ductile mode. Despite many guidelines for applying composite materials for retrofitting and predicting the performance of strengthened structures, the application of TRM systems in masonry walls is not extensively described. A thorough retrospect of the literature is presented, containing research results relating to different masonry walls, e.g., bricks, cement, and stone blocks strengthened with TRM jackets and subjected to diagonal compression loads. The critical issue of this study is the failure mode of the retrofitted masonry walls. Available prediction models are presented, and their predictions are compared to the experimental results based on their failure modes. The novelty of this study is the more accurate failure mode prediction of reinforced masonry with TRM and also of the shear strength with the proposed model, Thomoglou et al., 2020, at an optimal level compared to existing regulations and models. The novel prediction model estimates the shear failure mode of the strengthened wall while considering the contribution of all components, e.g., block, render mortar, strengthening textile, and cementitious matrix, by modifying the expressions of the Eurocode 8 provisions. The results have shown that the proposed model presents an optimum accuracy in predicting the failure mode of all different masonry walls strengthened with various TRM jackets and could be taken into account in the regulations for reliable forecasting. [ABSTRACT FROM AUTHOR]

Masonry is among the most widely used construction materials around the world. Contemporary masonry buildings are primarily designed to comply with prescriptive building code regulations. In recent decades, performance-based design (PBD) has gained increasing attention and achieved significant success in critical structures or infrastructure systems. Instead of being the first mover, the masonry research and practice community can be a faster follower in response to the design paradigm shift towards PBD for masonry buildings. A reliable performance assessment of masonry buildings is of paramount importance in the PBD framework. To facilitate this, this paper presents an up-to-date comprehensive literature review of experimental and analytical studies with emphasis on their contributions to advancement towards performance assessment of masonry buildings. This review categorized available works into two sub-topics: (1) traditional unreinforced masonry and (2) modern reinforced masonry. In each sub-topic, studies focusing on the structural behaviors of masonry at the component-level (i.e., masonry wall) are discussed first, followed by the building system-level-related studies. Through this literature review, the current state of the art and remaining research gaps are identified to provide guidance for future research needs and to pave the way for implementing PBD in the masonry industry. [ABSTRACT FROM AUTHOR]

The interfaces between masonry infill and reinforced concrete (MI-RC) frames are identified as the weakest regions under lateral loads. Hence, the behavior of such frames under lateral loads can be understood mainly through experimental investigations. The deformation demands induced by horizontal loads on RC frames with infill masonry walls change due to contact losses between the infill masonry and the RC frames. This can be controlled by providing proper reinforcements at the interfaces. In the present experimental investigation, three half-scaled models subjected to reversed cyclic lateral in-plane loads were tested. In detail, the specimens considered are the MI-RC frame model, an MI-RC frame with geo-fabric reinforcement at the interface and an MI-RC frame with geo-fabric reinforcement at interfaces with an open ground story. The models were subjected to reversed cyclic lateral in-plane loads, and the post-yield responses of the models with respect to stiffness degradation, drift, energy dissipation, ductility and failure mode have been discussed. [ABSTRACT FROM AUTHOR]

In order to investigate the seismic performance of a precast shear wall with a new bundled connection under a high axial compressive ratio, three full-scale precast short-limb shear walls and one full-scale cast-in-place short-limb shear wall were manufactured and loaded under cycling loading. The results show that the precast short-limb shear wall with a new bundled connection has a similar damage mode and crack evolution to the cast-in-place shear wall. Under the same axial compression ratio, the bearing capacity, ductility coefficient, stiffness, and energy dissipation capacity of the precast short-limb shear wall were better, and its seismic performance is related to the axial compression ratio, with the increase of the axial compression ratio. The embedded bellows can limit the cracking of the wall but have little effect on the bearing capacity and stiffness degradation performance. Furthermore, the bond between the vertical steel bars extending into the preformed holes and grouting materials was demonstrated to be reliable, thus ensuring the integrity of the precast specimens. [ABSTRACT FROM AUTHOR]

This study focused on perforated bricks, and the structural performance enhancement of brick members by internal reinforcement was experimentally investigated. As a new reinforcing material, screw iron (SI) rods were selected for the internal reinforcement, and they were inserted into the perforated brick. To investigate the most-effective reinforcing method as well as to understand the fundamental structural behaviors, four specimens with different variables were fabricated, and three-point bending tests were carried out. From the experiments, it was found that the maximum strength of the specimen increased by more than two times with internal reinforcement. The internal reinforcement, fixed by nuts at both ends of the specimen to enhance integrity, increased the maximum strength by nine times. Moreover, the deformation capacities of the specimens were also greatly enhanced. The case where the internal SI rods were fixed by nuts without mortar also showed a similar structural performance to the case with mortar. The estimation methods of the maximum strength of the specimens were also discussed, and they showed reasonable agreement with the test results. It was proved that the proposed material and methods enabled effective utilization of the internal reinforcement, and they could contribute to the improvement of structural performances in masonry construction. [ABSTRACT FROM AUTHOR]

Reinforced masonry constructions and their elements must meet strength and stability requirements. These conditions determine wall structure safety during construction and operation. Safety depends on diagnostically aimed tests that check the objects' quality or locate damages to structural elements that arise during operation. This article is focused on the experimental modal analysis research of reinforcement ceramic masonry elements. The aim of the research was to check whether it is possible to observe the damage in reinforced masonry structures and the accompanying vibration of signal transition functions by conducting pilot studies and using different types of reinforcements. The experiment was conducted on three samples of various types of reinforced brick walls. During the vibration tests, the segments were subjected to various loads, and it was observed how the increasing cracks and damage changed the courses of the measured functions of the vibration process, reflecting the damage to the segments. This made it possible to assess the variability of the vibration characteristics of the tested reinforced wall elements and the usefulness of the applied test method. The aim of the study was to check the assessed effectiveness by testing the degradation of the reinforced wall elements. The research confirmed the usefulness of the SISO methodology in identifying damages, which has been implemented in selected precast factories in Poland. [ABSTRACT FROM AUTHOR]

A large part of the European building stock was built before implementing the recent energy and structural codes, resulting in buildings characterized by deficiencies in terms of comfort, energy savings and structural safety. The retrofitting and rehabilitation of the existing building stock need to be adequately performed, aiming to improve the seismic and energy performance simultaneously. The work summarized here is dedicated to defining priority scenarios for buildings' retrofitting to improve the seismic safety and energy efficiency of the European Union (EU) building stock. First, the state of the EU building stock is analysed in terms of buildings' age, types of structures, energy efficiency, energy consumption and energy poverty. Then, the EU climate demands are presented, namely the regions with higher temperature variations, i.e., heating or cooling degree days. The EU seismic risk is also presented and discussed in terms of average annual losses, average annual economic losses and average annual life losses. Based on these input parameters, nine seismic–climate regions in the EU are proposed using a simplified approach. Finally, retrofitting scenarios are proposed for two types of buildings (i.e., masonry and reinforced concrete) based on their seismic–climate region. [ABSTRACT FROM AUTHOR]

Featured Application: The grouted sleeve lapping connector in this work has the advantages of low cost and ease of construction, and it can realize full prefabrication of vertical components. In this paper, pseudo-static tests of L-shaped shear walls with high axial compression ratio are carried out to investigate the connection reliability of the joint under seismic action. The grouted sleeve lapping connector called the APC connector has the advantages of high fault tolerance, convenient construction, compacted grouting, and low cost, together with realizing full prefabrication of vertical components. In this paper, a quasi-static test of two fully prefabricated L-shaped walls connected with two types of APC connector and a cast-in-place wall was carried out under high axial compression ratio (0.5) to compare their seismic performance. The results indicated that the two types of connectors effectively transferred the rebar stress in the prefabricated walls, and the failure modes and final crack distribution of the prefabricated walls and the cast-in-place wall were basically identical. The failure of the cast-in-place wall occurred at the root of the wall limb, while the failure of the prefabricated walls occurred at the top of the sleeve due to the constraint of the sleeve. The bearing capacity, stiffness, ductility, and energy dissipation of the prefabricated specimen connected by the type-I sleeve was comparable to that of the cast-in-place wall, while the prefabricated wall connected by the type-II sleeve showed greater bearing capacity, stiffness, and ductility. Finally, some suggestions for seismic design of prefabricated components connected with APC connectors are proposed. [ABSTRACT FROM AUTHOR]

Reducing the embodied and operational energy of buildings is a key priority for construction and real estate sectors. It is essential to prioritize materials and construction technologies with low carbon footprints for the design of new buildings. Off-site constructions systems are claimed to have the potential to deliver a low carbon build environment, but at present there are a lack of data about their real environmental impacts. This paper sheds lights on the environmental performance of two offsite technologies: cold formed steel and cross laminated timber. Specifically, the environmental impacts of a CFS technology are discussed according to six standard impact categories, which includes the global warming potential and the total use of primary energy. The study is based on a detailed cradle to gate life cycle analysis of a real case study, and discusses the impacts of both structural and non-structural components of CFS constructions. As a useful frame of reference, this work compares the environmental impacts of 1 m2 of walls and floors of CFS technology with those of cross laminated timber, which is spreading as innovative off-site technology for the development of nearly zero energy buildings, and a conventional reinforced masonry technology, which is largely adopted in the Italian construction sector. The paper concludes with the necessity to optimize structural systems to reduce the overall embodied carbon impacts. [ABSTRACT FROM AUTHOR]

The use of fabric-reinforced cementitious mortar (FRCM) or steel-reinforced grout (SRG) is now recognized to be effective in enhancing the axial capacity of masonry columns when confinement is achieved. Numerous experimental tests demonstrated the symbiotic role of the fabric and the inorganic matrix. An open issue is still related to the numerical simulation. In fact, if the compressive behavior by the numerical simulation of the unreinforced and reinforced masonry columns confined by a FRCM/SRG jacket may follow different approaches. The inorganic matrix transfers the stresses from the substrate to the fabric differently, depending on the presence or absence of cracks. The fabric consists of an open grid whose yard could be differently stressed after the matrix damage because of the occurrence of a possible slippage at the fabric–matrix interface. Definitely, these aspects are difficult to numerically predict. The paper herein is devoted to the assessment of different numerical approaches for the FRCM/SRG confinement of masonry columns by considering data from the literature and varying the parameters related to the matrix, the fabric, and the masonry itself. The goal is to best fit the experimental outcomes (from different available sources) with different strategies based on a finite element (FE) modeling. The results show good matching between the experimental and theoretical curves for the different FRCM/SRG systems. The results evidenced that the accuracy of the experimental versus the numerical curves match is met for the different FRCM/SRG systems. [ABSTRACT FROM AUTHOR]

To replace conventional concrete with coal gangue concrete in the construction industry, lateral cyclic loading tests were applied to three shear walls with different coal gangue replacement rates in this study, in which the replacement rate of coal gangue was 0%, 50%, and 100%. The load-displacement hysteretic curves and backbone curves of the shear walls obtained from tests were analyzed to compare the failure process and seismic performance of each shear wall. The results indicate that the stress performance and failure morphology of coal gangue concrete shear walls and conventional concrete shear walls are extremely similar, and the characteristics of the hysteretic and backbone curves are approximately the same. With the increase in the coal gangue replacement rate, the bearing capacity and ductility of the three shear walls gradually decrease, the strength degradation gradually becomes significant, and the energy dissipation capacity becomes worse, but the difference is not obvious, and all of them can meet the requirements of seismic performance. In addition, with the increase in the coal gangue replacement rate, the stiffness degradation gradually slows, so it is feasible to construct a shear wall using coal gangue concrete instead of conventional concrete. [ABSTRACT FROM AUTHOR]

In structural response array observation, the vibration response of a structure during an earthquake or from the natural environment is recorded and stored using high-sensitivity strong motion seismographs, and the dynamic characteristics of the structure are analyzed and determined using random signal data processing technology. Due to the use of field test data for analysis, this may be the most accurate and effective way to obtain the actual characteristics of the structure, which can be further used to verify the accuracy of theoretical analysis, experimental results, and numerical simulations. Therefore, this technique plays an important role in earthquake prevention and disaster reduction, with the application of strong motion observation data. In this paper, field vibration tests were performed on the highest reinforced masonry structure in China. With the test environmental vibration data, the natural vibration frequency values and mode shapes of the structure were identified using the peak picking method. A numerical modal analysis was then performed to verify the accuracy of the field test results. In addition, the structural response records obtained during an earthquakes in Songyuan were also used to identify the natural vibration frequency of the structure and the changes in the natural vibration frequency before, during, and after the earthquake. The results showed that the structure was not damaged during the earthquake and remained in an elastic state. [ABSTRACT FROM AUTHOR]

The material deterioration of an unreinforced stone masonry (URSM) building, due to subsequent dynamic loadings of increasing intensity on a shaking table, is investigated by means of inverse engineering, i.e. calibrating a finite element (FE) model to the experimental response data. The mechanical properties of the structure were initially estimated by preliminary characterisation tests. A two-storey full scale URSM building was tested on a shaking table using a sequential testing procedure of stationary and strong motion vibrations. The building was submitted to five uniaxial time-histories with gradually increasing intensity on a shaking table at the EUCENTRE laboratory (Pavia, Italy) up to a near collapse damage state, each one followed by a stationary vibration test. A frequency domain calibration was carried out to extract the mechanical properties of the equivalent elastic model. To this end, the stationary measurements were used to build up the state-space model. On the other hand, a recognition model was employed using the finite element method (FEM), whose stiffness and mass matrices were used to derive the corresponding analytical state-space model, which was compared to the experimental one. The calibration of the model against the experimental dynamic results includes increased complexity and high computational effort. Through an iterative optimisation trial and error procedure, the mechanical properties of masonry and the shear modulus of the flexible diaphragm of the structure for each test phase were derived. It is shown that the deterioration is more intense for the shear modulus of the walls compared to their elastic modulus. The ratio of the in-plane shear to the elastic modulus decreases substantially. The deterioration of the shear modulus of the timber floors is comparable with those of masonry walls. [ABSTRACT FROM AUTHOR]

Analyzing monitoring data efficiently is a classic problem in structural health monitoring. A nonparametric test method, the Mann–Kendall (MK) method, was implemented in this study, which is commonly used to detect monotonic trends in a series of environmental data. Using the MK method, three types of time series were studied: the stress time series measured in the concrete prism compression test, the resultant force time series obtained from the pseudostatic test of a reinforced masonry shear wall, and the translation velocity time series detected in a high-rise building. The statistics calculated, as well as the intersections of curves, indicate the trend change in the time series. The results demonstrated that the MK method could efficiently analyze the trend in the engineering time series. [ABSTRACT FROM AUTHOR]

In this study, several steel connector shapes were analytically evaluated as potential new seismic energy dissipating devices between vertical precast concrete shear wall panels. Based on the results of analytical and experimental studies, a multiple yield zone (MYZ) connector is proposed due to its improved performance (in energy dissipation) when compared to the conventional U-shaped flexure plate (UFP) device. Unlike the UFP, the MYZ connector provides stiffness and energy dissipation in both horizontal and vertical directions. The response of a shear wall building system utilizing the MYZ or UFP connectors was evaluated using a simplified frame model. The MYZ connector performed better than the UFP alternate both in terms of energy dissipation in the device and with respect to improved structure response. The use of multiple (distributed) yield zones through circular cut-outs is key in the performance enhancement observed with the MYZ connector. [ABSTRACT FROM AUTHOR]

Several masonry structures of cultural and historical interest are made with a non-periodic masonry material. In the case of periodic textures, several methods are available to estimate the strength of the masonry; however, in the case of non-periodic masonry, few methods are available, and they are frequently difficult to use. In the present paper we propose using discontinuity layout optimization (DLO) to estimate the failure load and mechanism of a masonry wall made with non-periodic texture. We developed a parametric analysis to account for the main features involved in the estimation of failure: in particular we considered three different textures (periodic, quasi-periodic, and chaotic), variable height-to-width ratio of the wall (from 0 to 3) and of the blocks (from 0.25 to 1), different mechanical properties of mortar joints and blocks, and possible presence of a load on the top. The results highlight the importance of the parameters considered in the analysis, both on the values of the failure load and on the failure mechanism. Therefore, it is found that DLO can be an useful and affordable method in order to assess the mechanical strength of masonry wall made with non-periodic textures. [ABSTRACT FROM AUTHOR]

The deterioration of mortar has an adverse impact on the deformation and stress state of the masonry arch dam, after freeze-thaw cycles, in long-term operation. The purpose of this paper is to investigate the effect of reinforcement grouting on the stress of a thin masonry arch dam and propose a reasonable grouting method in the case of mortar deterioration. The determination of the ultimate grouting pressure is another main focus. The masonry material was generalized by combining a linear elastic model and the proportional weighted average under the condition of deterioration caused by freeze-thaw cycles. A series of analytical methods were proposed for the research of grouting effect on dam stress, based on which the ultimate grouting pressure is calculated in various cases. Results demonstrate that the dam tensile stress may exceed the allowable value in the following operation. Then, some recommended methods for the grouting layout and the estimation of grouting pressure were put forward by integrating the grouting field test with numerical analysis for reinforcement. The research conclusions might have a guiding significance for the reinforcement of similar projects. [ABSTRACT FROM AUTHOR]

This paper presents the results of a parametric study on the response of unreinforced and retrofitted masonry specimens. The adopted strengthening technique is the steel-reinforced plaster, which is very commonly used but it is not supported by a proper theoretical and experimental characterization in the scientific literature. The aim was to investigate the main parameters that affect the structural performances of the walls. Several numerical models were implemented using the finite element method to analyze the influence of the bricks' arrangements, the mechanical properties of the mortar joints, the number of connectors, and the mechanical properties and thickness of the plaster coating. A concrete damage plasticity model was adopted to describe the bricks, the mortar joints, and the plaster behaviors. For the unreinforced specimens, the outcomes confirmed that the mortar strength had a significant influence on the performance of the wall, together with the presence of potential weaknesses in the bricks, while the bond effect was negligible. For reinforced walls, the connectors do not have a significant influence on retrofitted wall capacity but may prevent instability if a proper number is considered. Furthermore, the strength of the plaster coating does not affect the collapse load significantly, while increasing the fracture energy, which can be produced, for instance, by using fiber-reinforced concrete, increases the capacity of retrofitted walls, with more limited damage. Finally, an increase in the plaster thickness may be beneficial in terms of collapse load, even though greater thickness may increase the seismic masses significantly. [ABSTRACT FROM AUTHOR]

Featured Application: Numerical modelling and seismic capacity of dry-joint masonry structures. Heritage masonry structures are often modelled as dry-jointed structures. On the one hand, it may correspond to the reality where the initial mortar was weak, missing, or has disappeared through time because of erosion and lixiviation. On the other hand, this modelling approach reduces complexity to the studied problem, both from an experimental and theoretical/numerical point of views, while being conservative. Still, for modelling purposes, in addition to the joint friction, numerical approaches require a specific elastic parameter, the dry-joint stiffness, which is often hard to estimate experimentally. This work numerically investigates the effect of the joint stiffness on the collapse of scaled-down tilting test experiments carried out on perforated dry-joint masonry shear walls. It is found that geometrical imperfections of bricks and the absence of vertical precompression load can lead to very low equivalent dry-joint stiffness, which strongly affects the results, both in terms of collapse and damage limit state (DLS) loads, with practical implications for the engineering practice. [ABSTRACT FROM AUTHOR]

In this study, four single-story reinforced masonry shear walls (RMSWs) (two prefabricated and two cast-in-place) under reversed cyclic loading were tested to evaluate their seismic performance. The aim of the study was to evaluate the shear behavior of RMSWs with flanges at the wall ends as well as the effect of construction method. The test results showed that all specimens had a similar failure mode with diagonal cracking. However, the crack distribution was strongly influenced by the construction method. The lateral capacity of the prefabricated walls was 12% and 27% higher than that of the corresponding cast-in-place walls with respect to the rectangular and T-shaped cross sections. The prefabricated walls showed better post-cracking performance than did the cast-in-place wall. The secant stiffness of all the walls decreased rapidly to approximately 63% of the initial stiffness when the first major diagonal crack was observed. The idealized equivalent elastic-plastic system showed that the prefabricated walls had a greater displacement ductility of 3.2–4.8 than that of the cast-in-place walls with a displacement ductility value of 2.3–2.7. This proved that the vertical joints in prefabricated RMSWs enhanced the seismic performance of walls in shear capacity and ductility. In addition, the equivalent viscous damping of the specimens ranged from 0.13 to 0.26 for prefabricated and cast-in-place walls, respectively. [ABSTRACT FROM AUTHOR]

Earthquakes could be a hazard to human lives and the economy, leading to catastrophic disaster unless proper preparation is not made for buildings and infrastructures. To prevent catastrophes from earthquakes, new engineering technologies and seismic evaluation methods have been being developed [[1]]. This Special Issue also included three important topics on seismic performance evaluation of building structures: (1) novel seismic performance evaluation methods, (2) advanced numerical model and analysis methods to conduct seismic performance evaluation, (3) seismic hazard estimation methods, and (4) seismic loss estimation. [Extracted from the article]

Featured Application: The described numerical model is intended for analyses of stress states and deformations of precast reinforced lintels made of autoclaved aerated concrete (AAC) bonded with AAC masonry and reinforced concrete confining elements. This paper describes results of numerical analyses of reinforced lintels made of autoclaved aerated concrete built into unconfined walls and walls confined with reinforced concrete. The combination of the Menétrey–Willam elastic-plastic failure criterion (M-W-3) and the Rankine criterion was used for numerical analysis of masonry. The parameters were determined by laboratory tests. Rebars were modelled using the Huber–Mises–Hencky yield criterion. The numerical model included interface elements att the interface between masonry units, at interfaces between reinforced concrete and masonry, and at interfaces between elements of test stands with a model using the Coulomb–Mohr (C-M) criterion. The majority of parameters of interface elements were assumed from laboratory tests. Results of numerical analysis were compared with laboratory tests. Results of numerical analysis and experiments were compatible in the range of load-carrying capacity of models and the failure method. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The seismic performance of prefabricated reinforced concrete block masonry shear walls (PRMSWs) was studied. Five PRMSWs were tested under cyclic loading to evaluate the effect of the axial compression ratio and the distribution of the vertical rebar on the inelastic behavior. Based on the experimental results, the lateral load capacity, failure mode, lateral drift, ductility, stiffness degradation, energy dissipation, and the seismic performance stability of the specimens were analyzed. The finite element analysis of the specimens was conducted with ABAQUS, which agreed quite well with the laboratory findings. Relevant results showed that PRMSW exhibited favorable ductility and energy dissipation. The increase of the compression ratio led to stiffer, but more brittle, inelastic behavior of the specimens that had higher flexural strength. The shear walls that had concentrated vertical rebar at the sides exhibited relatively higher load capacity and less ductility compared to the walls that had evenly distributed rebar. The inelastic lateral drift limit of the PRMSW could be assigned 1/120. The equivalent viscous damping ratio of the PRMSW was 9–13% at ultimate load. These results provide a technical basis for the design and application of the PRMSW structures. [ABSTRACT FROM AUTHOR]

Typically, a special type of concrete block with cleaning holes is used in the bottom layer of traditional reinforced masonry shear walls (RMSWs) for mortar cleaning and vertical rebar connection, which results in reduced integrity and weakened structural behavior. In this paper, a precast construction technology was introduced to overcome these shortcomings. The cleaning-hole blocks were eliminated in the newly-developed precast RMSWs. Quasi-static tests on two traditional and two precast fully grouted RMSWs were conducted. The results showed that the flexural capacity of precast walls exhibited about a 10% increase when compared to traditional RMSWs under the same axial compression. Precast RMSWs that failed in flexural mode showed favorable deformation capacity and the displacement ductility value corresponding to 15% strength degradation reached 4.9. The wall stiffness degraded rapidly to 50% of the initial stiffness, K0, at 0.2% drift and, at 0.5% drift, the corresponding stiffness decreased to about 21% K0 at a more gradual rate. Furthermore, precast RMSWs exhibited significant energy dissipation capacity. The experiment suggests that precast RMSWs have a satisfactory seismic performance. [ABSTRACT FROM AUTHOR]

An increasing interest in the preservation of historic structures has produced a need for new methods for reinforcing curved masonry structures, such as arches and vaults. These structures are generally very ancient, have geometries and materials which are poorly defined and have been exposed to long-term historical movements and actions. Consequently, they are often in need of repair or reinforcement. This article presents the results of an experimental study carried out in the laboratory and during on-site testing to investigate the behaviour of brick masonry vaults under dynamic loading strengthened with FRPs (Fiber Reinforced Polymers). For the laboratory tests, the brick vaults were built with solid sanded clay bricks and weak mortar and were tested under dynamic loading. The experimental tests were designed to facilitate analysis of the dynamic behaviour of undamaged, damaged and reinforced vaulted structures. On-site tests were carried out on an earthquake-damaged thin brick vault of an 18th century aristocratic residence in the city of L'Aquila, Italy. The provision of FRP reinforcement is shown to re-establish elastic behavior previously compromised by time induced damage in the vaults. [ABSTRACT FROM AUTHOR]

Cantagallo et al. [[2]] proposed a multilevel procedure for the seismic safety assessment of historical constructions, based on three interrelated phases: building-knowledge acquisition, structural behavior analysis, and safety assessment. Vona et al. [[6]] proposed a resilience-based methodology for the seismic retrofit design of existing strategic RC buildings, considered either individually or on a large territorial scale. Structural rehabilitation has globally become an urgent need due to both widespread construction obsolescence and more demanding requirements from modern construction codes, especially in earthquake-prone areas, where upgrading the existing constructions has become a primary goal. Three main RC buildings compose the complex, standing from a common basement, very peculiar from both architectural and structural points of view. [Extracted from the article]

To improve the seismic behavior of shear walls, a new composite shear wall composed of a steel-fiber-reinforced high-strength concrete (SFRHC) web and two square concrete-filled steel tube (CFST) columns, namely a steel-fiber-reinforced concrete shear wall with CFST columns, is proposed in this paper. Therefore, the main purpose of this paper is to present an experimental investigation of the seismic behavior of the SFRHC shear wall with CFST columns. Pseudo-static tests were carried out on seven composite shear walls, and the seismic performance of the shear walls was studied and quantified in terms of the aspects of energy consumption, ductility and stiffness degradation. Furthermore, the experimental results indicated that adding steel fiber can effectively restrain the crack propagation of composite shear walls and further help to improve the ductility and energy dissipation capacity of composite shear walls and delay the degradation of their lateral stiffness and force. Moreover, the seismic behavior of the SFRHC shear wall with CFST columns was obviously superior to that of the conventionally reinforced shear wall, in terms of load-bearing capacity, ductility, stiffness and energy dissipation capacity, because of the confinement effect of the CFST columns on the web. Finally, the preliminary study demonstrated that the composite shear wall has good potential to be used in regions with high seismic risk. [ABSTRACT FROM AUTHOR]

Prefabrication has been shown to be an effective way of construction in the modern-day context. Although much progress has been made in developing reinforced concrete (RC), timber and steel prefabricated elements/structures, prefabrication of masonry walling systems has received limited attention in the past. Conventional masonry construction is labour-intensive and time-consuming; therefore, prefabrication can be an effective solution to accelerate the masonry construction to make it more cost-effective. Therefore, in this paper, an attempt has been made to evaluate the effectiveness of prefabricated masonry systems (PMS) in terms of their structural characteristics and sustainability perspectives in an Australian context. Subsequently, the available studies related to PMS and the prospects of developing prefabricated masonry walling systems were appraised and reported. In order to assess the applicability of PMS, a case study was carried out by designing four types of prospective prefabricated masonry walling systems for a typical housing unit in Australia. It was shown that the reinforced (RM), post-tensioned (PT) and thin layered mortared (TLM) masonry systems are better suited for prefabrication. Later, in order to assess the sustainability of the considered masonry walling systems, life cycle energy analyses were carried using the Environmental Performance in Construction (EPIC) database. It was found that there can be nearly 30% and 15% savings, respectively, in terms of energy saving and CO2 emissions in prefabricated construction than the conventional masonry construction. Finally, the prospects of developing PMS and the need for future research studies on these systems are highlighted. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

More than 226 million people are affected by some type of disaster every year in various dimensions of human life, both in the short and long term. In this context, housing provision plays a leading role when it comes to basic needs and the choice of construction technologies and materials are determinant for a well-succeeded housing provision process. This work aims to analyze the viability of reinforced masonry technology with cement-stabilized compressed earth blocks as an alternative for the (re)construction process in situations that involve disaster risk reduction (DRR). To address this issue, a discussion from the literature and the main results obtained during the investigations carried out within the scope of the Simple Housing Solution (SHS) Project are presented. In the sequence, analyses are performed under United Nations Development Program/International Recovery Platform sustainability recommendations: environmental, technical, financial and socio-organizational aspects. It is concluded that the technology of Compressed Earth Blocks (CEBs) reinforced structural masonry has a high potential to be successfully applied in DRR situations, especially when associated with the community construction system in a joint effort. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Architectural heritage is usually built with masonry structures, which present problems under lateral in-plane loading conditions, such as wind pressure or earthquakes. In order to improve the shear behavior of masonry, the use of a fabric-reinforced cementitious matrix (FRCM) has become an interesting solution because of its synergy of mechanical properties and compatibility with masonry substrates. For a proper structural evaluation, the mechanical behavior of reinforced masonry and the FRCM itself needs to be characterized. Hence, a numerical model to evaluate the FRCM reinforcement requires some mechanical parameters that may be difficult to obtain. In this sense, the shear behavior of masonry can be evaluated by means of diagonal tension tests on small specimens (71 × 71 cm). In this work, a digital image correlation (DIC) monitoring system was used to control displacements and cracking patterns of masonry specimens under shear stress (induced by diagonal tension with FRCM layers) applied to one or two sides. In addition, the mechanical behavior of FRCM coupons under uniaxial tensile tests was also registered with DIC. The displacement measurements obtained by DIC were validated with the measurements registered with LVDT. Unlike LVDT-based techniques, DIC monitoring allowed us to measure deformations in masonry during the full test, detecting crack initiation even before it was visible to the eye. [ABSTRACT FROM AUTHOR]