Seismic fragility and post-earthquake reparability of concrete frame with low-bond high-strength reinforced concrete column

Structures ◽  
2022 ◽  
Vol 37 ◽  
pp. 185-202
J.H. Wang ◽  
Y.P. Sun
2019 ◽  
Vol 22 (12) ◽  
pp. 2605-2619
Denghu Jing ◽  
Shuangyin Cao ◽  
Theofanis Krevaikas ◽  
Jun Bian

This article proposes a new connection between a steel bearing and a reinforced concrete column, which is mainly used for provisionally providing jack support in existing reinforced concrete structures. In this suggested connection joint, the steel bearing consisted of two or four symmetrical components assembled by high-strength bolts, which surrounds the reinforced concrete column by a tapered tube and balances the vertical load via the friction force between the tapered tube and concrete, that is, through a self-locking mechanism. The proposed connection joint can be assembled easily at a construction site and can also be disassembled and reused many times. To demonstrate the feasibility of this type of connection joint, a simple test was conducted to illustrate the concept, that is, a total of four medium-scale steel bearing–reinforced concrete column connections with circular cross sections were fabricated and tested under axial loading. The test results showed that the steel bearing–reinforced concrete column connection based on self-locking mechanism exhibited good working performance. Furthermore, a simplified formula to predict the axial stiffness of the connection joint was presented. From the tests and the proposed formula, the most important factors that influence the axial stiffness of this type of connection joint on the premise of an elastic working state are the slope of the tapered tube, the height of the steel bearing, the thickness of the tapered tube, the cross section of the reinforced concrete column, the cross-sectional area of all the connecting bolts, the proportion of the number of top bolts, the area of the top ring plate, and the effective contact area ratio.

2013 ◽  
Vol 742 ◽  
pp. 51-55
Guo Fu

Not collapse under strong earthquake is an important goal of the seismic design of reinforced concrete structure, seismic collapse resistance performance is directly affected by the deformation behavior of reinforced concrete column. The application of high-strength steel, high-strength stirrup and high-strength concrete can enhance the concrete material properties and mechanical properties of reinforced concrete column, but their deformation behavior have large differences. The research on the seismic performance of columns with high-strength materials, especially its deformation behavior, become the most important issue of anti-collapse analysis. In this paper, the ultimate displacement angle of concrete columns with high-strength materials were collected, the ultimate displacement angle and inter-story drift angle 1/50 were compared and analyzed. The results show that the average of ultimate displacement angle of the reinforced concrete column with high-strength stirrup and high-strength longitudinal bars are 0.0469, 0.0312, respectively, greater than inter-story drift angle 1/50, while the average of ultimate displacement angle with high-strength concrete and high-strength core concrete are 0.0147, 0.0167, less than 1/50, therefore, it is not suitable for taking 1/50 as the critical value of structure collapse with high-strength concrete. The inter-story drift angle should be different in the anti-collapse analysis.

2012 ◽  
Vol 479-481 ◽  
pp. 2041-2045
Yue Qi

Based on experimental research on plain concrete columns with high strength concrete core, the formula to predict the bearing capacity of concrete columns with high strength concrete core under axial compression loading was brought forward in previous paper, in order to verify the formula whether right, axial compression test including 3 concrete columns with high strength concrete core and 1 ordinary reinforced concrete column were completed, and the failure characteristic was analyzed additionally. According to experimental results, it can be shown that the failure modes of concrete columns with high strength concrete core are similar to that of ordinary reinforced concrete columns, however, the bearing capacity of concrete columns with high strength concrete core is significant higher compared with that of ordinary reinforced concrete column; the results of the bearing capacity obtained by the formula (2) was in good agreement with the experimental results.

2012 ◽  
Vol 193-194 ◽  
pp. 656-661 ◽  
Cedrick Mbang Matamb ◽  
Xiu Li Du ◽  
Jian Wei Zhang

This test was investigated on the compression failure in eccentric reinforced concrete square cross-section. In total twelve different scale specimens were eccentrically compressed with size of: 200×200mm; 400×400mm; 800×800mm. specimens were divided into 3 groups with 4 each. Only six columns have been investigated in this paper thus a column by eccentricity. The main point were based on the existence of size effect phenomenon on cross-section components collapsed with different sizes to the ultimate bearing capacity and the cross-section strain, ductility, deflection, and other failure characteristics. Analysis of the experimental data’s showed that the size effect phenomenon exists.

2018 ◽  
Vol 763 ◽  
pp. 763-770
Su Wen Chen ◽  
Meng Yang ◽  
Zhao Xin Hou ◽  
Guo Qiang Li ◽  
Qing Liu

High strength steel reinforced concrete (HSRC) column refers to steel reinforced concrete column using high strength steel with its yield strength over 420MPa. So far, research on seismic behavior of HSRC columns is limited. This paper presents experimental and numerical studies on seismic behavior of HSRC columns. Two Q460 high strength steel reinforced concrete columns have been tested under low cyclic loading with constant axial compression ratio of 0.3. Flexural failure is observed in the test. From the hysteresis curves, the specimens exhibit good ductility and satisfactory energy dissipation capacity. Displacement ductility factors are larger than 2. When load descends to 85% of the peak load, the ultimate drift ratios of two specimens are 1/29 and 1/26 respectively, which meet the requirements of Chinese Seismic Design code (GB 50011). To study the seismic behavior of HSRC columns more comprehensively, a numerical model has been established for simulating the experiment using OpenSees, which adopts nonlinear beam-column element and fiber model. The numerical result fits the test data well, which validates the effectiveness of numerical model. Parametric study is then carried out to further investigate the seismic behavior of HSRC columns.

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