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.

scholarly journals Experimental Investigation into the Seismic Performance of Prefabricated Reinforced Masonry Shear Walls with Vertical Joint Connections

2021 ◽  
Vol 11 (10) ◽  
pp. 4421
Author(s):  
Zhiming Zhang ◽  
Fenglai Wang
Keyword(s):  
Seismic Performance ◽  
Cross Sections ◽  
Shear Walls ◽  
Construction Method ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Reinforced Masonry ◽  
Cracking Performance

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.

scholarly journals Seismic Performance of Recycled Concrete Filled Circular Steel Tube Columns

2020 ◽  
Vol 7 ◽  
Author(s):  
Dingyi Xu ◽  
Zongping Chen ◽  
Chunheng Zhou
Keyword(s):  
Seismic Performance ◽  
Coarse Aggregate ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Recycled Concrete ◽  
Load Range ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Recycled Coarse Aggregate ◽  
Circular Steel Tube

This study was conducted to experimentally investigate the behavior of recycled concrete-filled circular steel tube (RCFST) columns subjected to cyclic loading. Ten specimens were prepared and tested. Four parameters were used to characterize seismic behavior: the replacement percentage of recycled coarse aggregate, slenderness ratio, axial compression level, and steel ratio. A novel calculation method for the bearing capacity for RCFST columns is established. The failure processes and modes of RCFST columns are found to be similar to normal concrete-filled steel tube columns. Varying the replacement percentage of recycled coarse aggregate has little effect on the hysteresis curves of the RCFST columns. The RCFST columns also show seismic performance similar to that of concrete-filled steel tubes. The displacement ductility of all specimens is larger than 3.0 and the equivalent viscous damping coefficients corresponding to the ultimate load range from 0.305 to 0.460.

scholarly journals Seismic Material Properties of Reinforced Concrete and Steel Casing Composite Concrete in Elevated Pile-Group Foundation

2015 ◽  
Vol 22 (s1) ◽  
pp. 141-148 ◽  
Author(s):  
Mi Zhou ◽  
Wancheng Yuan ◽  
Yue Zhang
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Damping Ratio ◽  
Pile Group ◽  
Ocean Engineering ◽  
Static Loads ◽  
Equivalent Viscous Damping ◽  
Static Tests ◽  
Equivalent Viscous Damping Ratio ◽  
Positive Effect

Abstract The paper focuses on the material mechanics properties of reinforced concrete and steel casing composite concrete under pseudo-static loads and their application in structure. Although elevated pile-group foundation is widely used in bridge, port and ocean engineering, the seismic performance of this type of foundation still need further study. Four scale-specimens of the elevated pile-group foundation were manufactured by these two kinds of concrete and seismic performance characteristic of each specimen were compared. Meanwhile, the special soil box was designed and built to consider soil-pile-superstructure interaction. According to the test result, the peak strength of strengthening specimens is about 1.77 times of the others and the ultimate displacement is 1.66 times of the RC specimens. Additionally, the dissipated hysteric energy capability of strengthening specimens is more than 2.15 times of the others as the equivalent viscous damping ratio is reduced by 50%. The pinching effect of first two specimens is more obvious than latter two specimens and the hysteretic loops of reinforced specimens are more plumpness. The pseudo-static tests also provided the data to quantitatively assessment the positive effect of steel casing composite concrete in aseismatic design of bridge.

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.

Discussion of Different Methods of Strengthening Masonry Walls with Constructional Column

2012 ◽  
Vol 226-228 ◽  
pp. 1098-1101
Author(s):  
Cheng Wang ◽  
Yong Kun Luo ◽  
Xiao Long Xu
Keyword(s):  
Finite Element ◽  
Seismic Performance ◽  
Large Scale ◽  
Rapid Development ◽  
Masonry Wall ◽  
Earthquake Resistance ◽  
Masonry Walls ◽  
Finite Element Software ◽  
Engineering Discipline ◽  
Constructional Column

With the rapid development of economy and the civil engineering discipline, the seismic performance of existing masonry wall can't satisfy the codes and regional seismic requirements. As a result, strengthening the earthquake resistance of it is put on the agenda. Using large-scale finite element software-abaqus, this paper analyzes different methods of strengthening masonry walls by constructional columns. Under the premise of the cross area of the columns used to reinforce is identical, it shows that the wall strengthened by bilateral constructional columns has a better seismic performance than by unilateral constructional column. The ductility coefficient of the former increases 49.4% than the original masonry, while the latter increases 26.3%. The bilateral constructional column could significantly improve the integrity and ductility of the masonry wall, so does the seismic performance. It has engineering sense for the strengthening work.

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.

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.

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 Experimental Study on Seismic Performance of Old Masonry Walls

2020 ◽  
Vol 20 (6) ◽  
pp. 151-157
Author(s):  
Hoijin Kim ◽  
Zheongzun Yi ◽  
Jongsup Park ◽  
Junsuk Kang
Keyword(s):  
Experimental Study ◽  
Seismic Performance ◽  
Initial Crack ◽  
Masonry Wall ◽  
Masonry Structure ◽  
Risk Level ◽  
Control Group ◽  
Masonry Walls ◽  
Masonry Building ◽  
Expected Increase

Due to the increase in the frequency and intensity of earthquakes and the number of old buildings and in Korea, there is an expected increase in the damage to life and property. Therefore, we intend to derive an indicator to evaluate the risk level by conducting a seismic test on old buildings. An initial crack was generated in the masonry structure to reflect the deterioration. The effect of the deterioration on the building was subsequently analyzed by comparing it with the uncracked control group. As a result, the masonry wall, which was the specimen, satisfied the seismic performance, but local failure occurred along the initial crack in the specimen considering the aging. The safety was significantly decreased due to the occurrence of additional cracks. This demonstrates that the cracks caused by the aging of the masonry building greatly damaged the seismic performance of the building.

Experimental Study on Improving Seismic Performance of Load-Bearing Masonry Walls Made of Autoclaved Aerated Concrete

2013 ◽  
Vol 671-674 ◽  
pp. 661-667
Author(s):  
Jing Hai Yu ◽  
Jian Feng Cao ◽  
Tian Hui Fei
Keyword(s):  
Experimental Study ◽  
Seismic Performance ◽  
Engineering Practice ◽  
Masonry Walls ◽  
Load Bearing ◽  
Displacement Ductility ◽  
Block Wall ◽  
Aerated Concrete ◽  
Constructional Column ◽  
Reversed Cyclic

Experiments of a piece of comparable block wall and five pieces of block walls with different constructional type subjected to low reversed cyclic loading have been conducted. Investigation has been made on the failure pattern, hysteretic loop curves, displacement-restoring capacity and displacement ductility of walls. The experimental results revealed that the seismic performance of block masonry walls, which used the constructional column and concrete strips, was improved remarkably. It set a sound basis for further analysis research and engineering practice on AAC load-bearing walls in the future.

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