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 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 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.

Experimental Seismic Performance Evaluation of Unreinforced Brick Masonry Shear Walls

2015 ◽  
Vol 31 (1) ◽  
pp. 215-246 ◽  
Author(s):  
Mohammed Javed ◽  
Guido Magenes ◽  
Bashir Alam ◽  
Akhtar Naeem Khan ◽  
Qaisar Ali ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Primary Source ◽  
Shear Walls ◽  
Brick Masonry ◽  
Stone Masonry ◽  
Masonry Buildings ◽  
Kashmir Earthquake ◽  
Equivalent Viscous Damping ◽  
Seismic Performance Evaluation ◽  
Story Drift

Unreinforced masonry buildings, constructed with stones or bricks, are common in the northern areas of Pakistan. In the October 2005 Kashmir earthquake, the seismic performance of stone masonry buildings was found to be poor, which was the primary source of fatalities. Unreinforced brick masonry (URBM) buildings, however, performed well even in severely jolted areas. The performance of URBM could have been much better if the affected buildings were constructed by using proper guidelines. Taking lessons from the disaster, an experimental investigation, based on typical geometry and precompression levels of the URBM shear walls in the affected region, was conducted to evaluate their seismic performance. Twelve walls were tested in the in-plane direction using quasi-static cyclic loading. First-story drift ratios for various performance levels in URBM buildings are proposed. The influences of relative precompression level and aspect ratio on the damage pattern, ultimate drift ratio, and equivalent viscous damping of the walls are examined.

scholarly journals Simplified Data-Driven Model for the Moment Curvature of T-Shaped RC Shear Walls

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Wang ◽  
Wenzhe Cai ◽  
Qingxuan Shi
Keyword(s):  
Cross Sections ◽  
Limit State ◽  
Shear Walls ◽  
Load Ratio ◽  
Ultimate Limit State ◽  
Limit States ◽  
Displacement Ductility ◽  
And Performance ◽  
Displacement Based ◽  
Ductility Capacity

Sectional deformation quantities, such as curvature and ductility, are of prime significance in the displacement-based seismic design and performance evaluation of structural members. However, few studies on the estimates of curvatures at different limit states have been performed on asymmetric flanged walls. In this paper, a parametric study was performed for a series of T-shaped wall cross-sections based on moment-curvature analyses. By investigating the effects of the axial load ratio, reinforcement content, material properties, and geometric parameters on curvatures at the yield and ultimate limit state, we interpret the variation in curvature with different influencing factors in detail according to the changes of the neutral axis depth. Based on the regression analyses of the numerical results of 4941 T-shaped cross-sections, simple expressions to estimate the yield curvature and ultimate curvature for asymmetric flanged walls are developed, and simplified estimates of the ductility capacity including curvature ductility and displacement ductility are further deduced. By comparing with the experimental results, we verify the accuracy of the proposed formulas. Such simple expressions will be valuable for the determination of the displacement response of asymmetric flanged reinforced concrete walls.

Experimental Study on Seismic Behavior of Double-Wall Precast Concrete Shear Wall

2014 ◽  
Vol 919-921 ◽  
pp. 1812-1816 ◽  
Author(s):  
Quan Dong Xiao ◽  
Zheng Xing Guo
Keyword(s):  
Energy Dissipation ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Precast Concrete ◽  
Shear Walls ◽  
Shear Wall ◽  
Initial Stiffness ◽  
Displacement Ductility ◽  
Energy Dissipation Capacity ◽  
Double Wall

To study the seismic behavior of Double-Wall Precast Concrete (DWPC) shear wall, three full scale specimens are tested and compared under low-cyclic reversed loading, including two DWPC shear walls and one normal Cast-In-Situ (CIS) shear wall. By observing their experimental phenomena and failure modes, contrasting their displacement ductility coefficients, hysteretic curves, skeleton curves and energy dissipation capacity, the seismic behavior were synthetically evaluated on aspects of strength, stiffness, ductility and energy dissipation. Compared with CIS specimen, DWPC specimens have higher initial stiffness, increased cracking loads by 43% to 47%, and the ultimate loads increased by 22% to 23%. The displacement ductility ratios also meet the ductility requirements with value of 5. The hysteretic curves of three specimens are plump, and the trend of skeleton curves is basically the same. The DWPC specimens demonstrated a good energy dissipation capacity. All the specimens had shown favorable seismic performance.

scholarly journals Tests on Seismic Behavior of Pre-cast Shear Walls with Vertical Reinforcements Spliced by Two Different Grout Ways

2015 ◽  
Vol 9 (1) ◽  
pp. 382-387 ◽  
Author(s):  
Lv Yajun ◽  
Guan Naiyan
Keyword(s):  
Seismic Performance ◽  
Failure Modes ◽  
Shear Walls ◽  
Shear Wall ◽  
Test Results ◽  
Skeleton Curve ◽  
Static Tests ◽  
Displacement Ductility ◽  
Performance Decline ◽  
Cast Concrete

To evaluate the seismic performance of pre-cast concrete shear wall with vertical reinforcements spliced by two different grout ways, quasi-static tests of two concrete shear walls holed by prefabricated corrugated pipe and one concrete shear wall holed by drawing out the pipe were tested. The test results showed that the wall holed by prefabricated corrugated pipe was basically the same as the wall holed by drawing out the pipe in failure modes. The hysteretic curves of the specimens are full, the trend of the skeleton curve is basically the same and the capacity of the energy dissipation is close. The displacement ductility factors are more than 4. For the two walls holed by prefabricated corrugated pipe, when the lap length is reduced, the seismic performance decline as well, but the wall still meets the current seismic code requirements.

scholarly journals Experimental Study on Seismic Behavior of Masonry Walls Strengthened by Reinforced Mortar Cross Strips

2019 ◽  
Vol 11 (18) ◽  
pp. 4866 ◽  
Author(s):  
Dong ◽  
Sui ◽  
Jiang ◽  
Zhou
Keyword(s):  
Seismic Performance ◽  
Cyclic Load ◽  
Failure Modes ◽  
Shear Failure ◽  
Constant Load ◽  
Shear Capacity ◽  
Experimental Program ◽  
Test Results ◽  
Reinforced Masonry ◽  
Key Factor

Due to the poor seismic performance, strengthening of masonry structures is always a significant problem worthy to study. It has been proven that the bearing capacity of existing masonry buildings can be enhanced greatly with efficient strengthening measures. An experimental program was conducted to investigate seismic performance of un-reinforced masonry (URM) walls strengthened b,y reinforced mortar (RM) cross strips. Eleven walls were tested under horizontal low-cyclic load, simultaneously with a vertical constant load on the top face. Three URM walls were tested as reference. The other eight walls were externally strengthened with 40 and 60 mm thick of RM cross strips on one or both faces. Test results showed that externally strengthening with RM cross strips was an efficient way to enhance the seismic performance of URM walls. The failure modes were divided into shear failure and shear-compression failure. All the tested walls did not collapse until the test ended, while many diagonal cracks and few vertical cracks appeared on mortar strips. After strengthening, the shear capacity of the strengthened walls increased by at least 38.2%, and the reinforcement ratio was noted to be the key factor to influence the shear capacity with positive correlation. Besides, RM cross strips did improve deformation capacity greatly.

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