A self-locking steel bearing connection for circular reinforced concrete columns

2019 ◽  
Vol 22 (12) ◽  
pp. 2605-2619
Author(s):  
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.

Author(s):  
Urška Bajc ◽  
Miran Saje ◽  
Tomaž Hozjan ◽  
Igor Planinc ◽  
Sebastjan Bratina

The influence of the cross-sectional dimensions on the buckling load capacity of reinforced concrete column exposed to ISO fire load is presented. The fire analysis is divided in two separate phases. In the first phase, the calculation of the temperatures over the cross-section of the concrete column is performed. Here more advanced hygro-thermal analysis is executed to take into account the influence of moisture on the distribution of the temperatures. In the second step of the fire analysis, the mechanical analysis is performed. The mechanical and thermal properties of concrete and reinforcement at elevated temperatures are used in accordance with EN 1992-1-2 (2004). For two different cross-sections, the parametric study has been performed. The critical buckling time and critical buckling capacity as a function of a load and slenderness of reinforced concrete column have been determined.


2013 ◽  
Vol 742 ◽  
pp. 51-55
Author(s):  
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
Author(s):  
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.


2014 ◽  
Vol 661 ◽  
pp. 111-117 ◽  
Author(s):  
Ahmad Zakiah ◽  
Ahmad Nursafarina ◽  
Azerai Ali Rahman ◽  
Hanizah Abdul Hamid ◽  
Mohammad Soffi Md Noh

This paper reports the investigation on the fire resistance performance of reinforced concrete column with embedded permanent formwork from woodwool board (WWCB). A series of slender column embedded with and without WWCB with cross-sections 200 mm x 200 mm for column without WWCB and 300 mm x 300 mm with embedded 50 mm thick WWCB. The height of the slender column was 2000 mm. The fire resistance test was performed in accordance with BS 476-22:1987 for two (2) hours fire exposure. The fire resistance test for the embedded column with WWCB was classified as “good” in resisting fire and heat transfer.


2008 ◽  
Vol 400-402 ◽  
pp. 269-274 ◽  
Author(s):  
Naveed Anwar ◽  
Mohammad Qaasim

Several parameters and corresponding performance of reinforced concrete column cross-sections of different shapes (square, rectangular, circular, T-shape, I-shape, cross-shape, L-shape and C-shape) under various loading conditions have been studied in order to determine the suitable and optimum cross-sections for strength and ductility. In each cross-section shape, parameters include compressive strength of concrete (f’c), tensile strength of steel (fy), steel ratio (As/Ag), and angle of bending. In order to demonstrate the behavior and performance of the sections in terms of strength and ductility, CSISectionBuilder software was used to define the stress-strain curve for concrete and steel and then compute the moment-curvature relationship for each section. Considering different sections, the number of parameters in every section and various loading conditions, a total of around 1,800 sections were analyzed. The comparison procedures started within each section shape, and then across different sections in order to determine the most suitable cross-section for strength and ductility. Results of the study are deemed very useful in the system selection and preliminary design of important structures such as buildings with complicated geometry and high architectural demand including bridge piers and hydraulic structures.


2012 ◽  
Vol 193-194 ◽  
pp. 656-661 ◽  
Author(s):  
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.


Sign in / Sign up

Export Citation Format

Share Document