Confined Masonry Shear Walls: Experimental Testing and Analysis

The composite shear wall has various merits over the traditional reinforced concrete walls. Thus, several experimental studies have been reported in the literature in order to study the seismic behavior of composite shear walls. However, few numerical investigations were found in the previous literature because of difficulties in the interaction behavior of steel and concrete. This study aimed to present a numerical analysis of smart composite shear walls, which use an infilled steel plate and concrete. The study was carried out using the ANSYS software. The mechanical mechanisms between the web plate and concrete were investigated thoroughly. The results obtained from the finite element (FE) analysis show excellent agreement with the experimental test results in terms of the hysteresis curves, failure behavior, ultimate strength, initial stiffness, and ductility. The present numerical investigations were focused on the effects of the gap, thickness of infill steel plate, thickness of the concrete wall, and distance between shear studs on the composite steel plate shear wall (CSPSW) behavior. The results indicate that increasing the gap between steel plate and concrete wall from 0 mm to 40 mm improved the stiffness by 18% as compared to the reference model, which led to delay failures of this model. Expanding the infill steel plate thickness to 12 mm enhanced the stiffness and energy absorption with a ratio of 95% and 58%, respectively. This resulted in a gradual drop in the strength capacity of this model. Meanwhile, increasing concrete wall thickness to 150 mm enhanced the ductility and energy absorption with a ratio of 52% and 32%, respectively, which led to restricting the model and reduced lateral offset. Changing the distance between shear studs from 20% to 25% enhanced the ductility and energy absorption by about 66% and 32%, respectively.

Mega steel braced frame-composite steel plate shear wall structure, consisting of mega steel braced frame as outer frame and composite steel plate shear walls as core wall, is a new type of hybrid structure that is proposed in this study. Seismic performance of this new structure was analyzed under frequent earthquake and severe earthquake. The analysis focused mainly on displacement response, seismic base shear distribution and failure mechanism. Comparing with traditional steel frame-RC core wall structure, this new type of hybrid structure presents better coorporative working performance since mega steel braced frame provides larger stiffness and composite steel plate shear wall provides a fairly ductile response. It can be observed from the failure mechanism that this structure has multiple seismic resistant systems with composite steel plate shear wall, mega braces and mega frame when subjected to severe earthquakes.

The use of common reinforced concrete shear walls in high rise buildings is sometimes limited because of the large amount of reinforcement localized at the end of the element. A good alternative in avoiding this disadvantage is to use composite steel concrete structural shear walls with steel encased profiles. This solution used for high rise buildings, offers to designers lateral stiffness, shear capacity and high bending resisting moment of structural walls. The encasement of the steel shapes in concrete is applied also for the following purposes: flexural stiffening and strengthening of compression elements; fire protection; potentially easier repairs after moderate damage; economy with respect both to material and construction. Until now in the national and international literature poor information about nonlinear behaviour of composite steel concrete structural shear walls with steel encased profiles is available. A theoretical and experimental program related to the behaviour of steel concrete structural shear walls with steel encased profiles is developed at “Politehnica” University of Timisoara. The program refers to six different elements, which differ by the shape of the steel encased profile and also by the arrangement of steel shapes on the cross section of the element. In order to calibrate the elements for experimental study some numerical analysis were made. The paper presents the results of numerical analysis with details of stress distribution, crack distribution, structural stiffness at various loads, and load bearing capacity of the elements.

An experimental study was performed to investigate the structural capacity of composite steel plate walls with trilateral constrained. Six one-third-scale models of one-story prototype walls with composite steel plate shear walls were tested. The parameters for this test were the width-thickness ratio of infill steel plates and the strength of compound precast plate. Regardless of the infill plate design, the steel plate wall specimens exhibited excellent strength, deformation capacity. The design of boundary connection method is important to small width-thickness ratio of infill plates. Bolt sliding between the infill steel plates and boundary frame would decrease initial stiffness and shear strength of the steel plate shear walls. And more, this result indicates that the initial stiffness and shear strength would be improved highly with compound precast plate as resistant-lateral of infill steel plate. But the precast plate must be have sufficient strengh in design.

Experimental tests on seismically damaged composite steel concrete walls retrofitted with CFRP composites

Modular integrated construction (MIC) is an innovative prefabricated building system that involves connecting precast concrete modular units with cast‐in‐place concrete. In this system, MIC composite shear walls and infill walls serve as the primary vertical components. However, due to the fundamental differences in the coordinated deformation mechanisms between infill walls and the main structure, as opposed to those in traditional cast‐in‐place structures, the influence of infill walls on MIC composite shear walls remains unclear. To address this issue, three composite shear wall specimens with varying structural configurations were designed for this study. Quasi‐static loading tests were conducted to analyze the complete mechanical response, failure mechanisms, hysteretic behavior, strength degradation, stiffness degradation, and energy dissipation capacity of the specimens. The test results indicated that all three specimens experienced flexure‐shear failure. Their hysteresis loops were well developed, stiffness gradually degraded, and energy dissipation capacities were favorable. The infill wall significantly influenced the failure mode of the MIC composite shear wall. Compared to the bare specimen DZ‐1, specimen DZ‐2 with infill walls exhibited a 40.8% enhancement in ultimate load‐bearing capacity and a 26% increase in cumulative energy dissipation capacity. However, this configuration also induced accelerated strength degradation and a reduction in structural ductility. By incorporating a flexible isolation panel connection, specimen DZ‐3 demonstrated a 7.7% reduction in ultimate load‐bearing capacity and a 9% decrease in cumulative energy dissipation compared to DZ‐2. Nonetheless, this design effectively enhanced structural ductility and mitigated stiffness degradation. Based on experimental findings, a refined finite element model of the wall was developed using ABAQUS software to further investigate the collaborative load‐bearing mechanisms between MIC composite shear walls and infill walls of varying dimensions and material types. Corresponding design recommendations were subsequently proposed. This study clarifies the coordination mechanism of infill walls and their previously underexplored seismic performance, thereby establishing a theoretical foundation for MIC composite shear walls. Based on these findings, corresponding design recommendations are proposed to advance the development of prefabricated modular construction.

The objectives of this paper are to experimentally study the in-plane behavior of fully grouted (FG) reinforced concrete masonry shear walls, explore the influence of different parameters, e.g. size of specimen and aspect ratio, on the lateral resistance of such walls, assess the appropriateness of the existing analytical shear strength prediction methods, and determine the influence of mortar formulation in the behavior of such walls. To accomplish this, four fully-grouted Special Reinforced Masonry Shear Walls (SRMSW) were constructed based on the provisions of the Masonry Standards Joint Committee (MSJC) 2008 code and subjected to in-plane reversed cyclic displacements. Full-size/full-scale walls were chosen to better represent walls in real buildings, and were the largest walls tested to date. The experimental test variables included mortar formulation and unit type (concrete and clay). To aid in satisfying the objectives, current test walls are compared with 43 wall specimens which exhibited shear failure modes, and 15 wall specimens that exhibited flexural failure modes in the past research studies. The results of this study indicate that although the shear strength expression adopted by MSJC (2008) is conservative for most fully grouted reinforced masonry shear walls, this conservatism decreases as the size of the wall increases. For the two fully grouted reinforced clay block masonry shear walls tested in this research program, with reinforcement located at 1220 mm (48 in.) on center, it is found that the MSJC (2008) shear strength expression is unconservative, which shows a potential knowledge gap related to the behavior of such walls. Moreover, it was concluded that, despite minor influence on the type of failure and energy dissipation of the shear walls, mortar formulation does not impact the shear resistance of fully grouted reinforced masonry shear walls.

Numerical study on the response of composite shear walls with steel sheets under cyclic loading

Experimental study of flexural critical reinforced concrete filled composite plate shear walls

Seismic performance of composite plate shear walls

Shear wall is the main component that resists the lateral force for high-rise buildings. With the rapid development of high-rise buildings, especially the super high-rise buildings, requirements for seismic performance of shear walls have become more sophisticated. The steel plate concrete composite shear wall shows good seismic performance. It has made rapid development through the research of seismic performance in the way of seismic design to the practical engineering application of steel plate concrete composite shear wall. Recent research situation and prospect of composite shear wall around the world have been introduced in this paper.

The objective of this study is to use autoclaved aerated concrete (AAC) for infill walls in existing buildings that are unsafe for earthquakes to increase their stiffness. The study included two topics; the first topic introduced six models using AAC in buildings resistance to earthquakes and the effect of self-weight of the buildings comparing bare frame clay partition masonry model (1), bare frame AAC partition masonry model (2), reinforced concrete frames clay infill wall model (3), reinforcement concrete frames AAC infill wall model (4), reinforcement concrete frames AAC infill wall core model (5), reinforcement concrete frames AAC infill wall first and second floors model (6). ETABS software was used to investigate all frame models. Results of the study revealed that AAC infill wall decreases base moment, base shear and displacement. On the other hand, second topic presented five models of single reinforcement concrete frame under lateral loading, considering effect of anchored and unanchored AAC infill wall and clay infill wall. These models are bare frame model (a), RC frame with clay infill wall unanchored model (b), RC frame with AAC infill wall unanchored model (c), RC frame with clay infill wall with anchors model (d), RC frame with AAC infill wall with anchors model (e). Using finite element software (ANSYS WORKBENCH 18.2) failure load, displacement and ductility were presented for all five frames. The results showed that the ‘RC frame with AAC infill wall with anchors’ model gives the biggest failure load whereas displacement and ductility are the lowest.

The seismic resistance of story‐height reinforced masonry shear walls has been evaluated experimentally to examine the influence of the applied axial stress and the amount of vertical and horizontal reinforcement on the lateral resistance, failure mechanism, ductility, and energy‐dissipation capability of a wall panel. The results obtained from 16 concrete masonry specimens are summarized in this paper. It has been shown that the flexural strength increases with the applied axial stress and the amount of the vertical reinforcement present. The shear strength dominated by diagonal cracking increases with the amount of vertical and horizontal steel, as well as with the tensile strength of masonry and the applied axial stress. However, the axial stress has a more significant influence on the flexural strength than on the shear strength. Furthermore, increasing the amount of vertical and horizontal reinforcement can substantially improve the postcracked ductility and energy‐dissipation capability of a shear‐dominated specimen.

A composite shear wall concept based on concrete filled steel tube (CFST) columns and steel plate (SP) deep beams is proposed and examined in this study. The new wall is composed of three different energy dissipation elements: CFST columns; SP deep beams; and reinforced concrete (RC) strips. The RC strips are intended to allow the core structural elements — the CFST columns and SP deep beams — to work as a single structure to consume energy. Six specimens of different configurations were tested under cyclic loading. The resulting data are analyzed herein. In addition, numerical simulations of the stress and damage processes for each specimen were carried out, and simulations were completed for a range of location and span-height ratio variations for the SP beams. The simulations show good agreement with the test results. The core structure exhibits a ductile yielding mechanism characteristic of strong column-weak beam structures, hysteretic curves are plump and the composite shear wall exhibits several seismic defense lines. The deformation of the shear wall specimens with encased CFST column and SP deep beam design appears to be closer to that of entire shear walls. Establishing optimal design parameters for the configuration of SP deep beams is pivotal to the best seismic behavior of the wall. The new composite shear wall is therefore suitable for use in the seismic design of building structures.

This paper presents an approach based on an acoustic emission technique for the health monitoring of steel–concrete (SC) composite shear walls. SC composite walls consist of plain (unreinforced) concrete sandwiched between steel faceplates. Although the use of SC system construction has been studied extensively for nearly 20 years, little-to-no attention has been devoted to the development of structural health monitoring techniques for the inspection of damage of the concrete behind the steel plates. In this work an unsupervised pattern recognition algorithm based on probability theory is proposed to assess the soundness of the concrete infill, and eventually provide a diagnosis of the SC wall’s health. The approach is validated through an experimental study on a large-scale SC shear wall subjected to a displacement controlled reversed cyclic loading.