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1
Huo, Bao Rong, and Xiang Dong Zhang. "Axial Compression Test and Capacity Caculation of RC Columns Consolidation with BFRP, CFRP." Applied Mechanics and Materials 94-96 (September 2011): 481–84. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.481.
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Abstract：Twenty-one RC columns were made, including nine RC columns wrapped with BFRP, nine RC columns wrapped with CFRP, three RC columns without any reinforcement, to conduct the comparative study of axial compression. The result shows that the bearing capacity of the RC columns reinforced with the fibers increases obviously. The bearing capacity of the RC columns with CFRP is higher than that with BFRP, but the difference is not obvious. The displacement ductility factor increases, but its increase rate becomes slow with increasing layers of fiber cloth, so the most economical layer number is 3. Based on the confinement mechanism of FRP cloth and the calculation formula of the bearing capacity for common RC column, the formula of the bearing capacity for reinforced RC column with BFRP cloth is proposed. The result of calculation basically tallies with the number in experiment.
2
Mohamed Sayed, Ahmed, Mohamed Mohamed Rashwan, and Mohamed Emad Helmy. "Experimental Behavior of Cracked Reinforced Concrete Columns Strengthened with Reinforced Concrete Jacketing." Materials 13, no. 12 (June 24, 2020): 2832. http://dx.doi.org/10.3390/ma13122832.
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Reinforced concrete (RC) columns often need to be strengthened or rehabilitated to allow them to carry the loads applied to them. In previous studies, RC columns have been strengthened by jacketing, without considering the occurrence of cracking. In this study, the behavior of RC columns strengthened externally by jacketing after cracking is analyzed. The accuracy of the existing models was verified by analyzing the performance of fifteen RC columns with different cross-sections to determine the effect of new variables, such as the column size, amount of steel reinforcement, and whether the column was cracked or not, on the effectiveness of strengthening. The analysis demonstrated that this strengthening technique could effectively improve both the ductility and strength of RC column cross-sections. The results indicate that the model suggested by the ACI-318 code can predict the ultimate load capacity of RC columns without strengthening, or strengthened by RC jacketing before or after cracking, with higher accuracy and material efficiency. The RC columns without strengthening met the safety limit of the ACI-318 model. However, for strengthened columns, a reduction coefficient must be used to enable the columns to meet the safety limit, with values of 94% and 76% for columns strengthened before and after cracking, respectively. Furthermore, strengthening after cracking affects the ultimate load capacity of the column, with 15.7%, 14.1%, and 13.5% lower loads for square, rectangular, and circular columns than those strengthened before cracking, respectively.
3
Huo, Bao Rong, and Xiang Dong Zhang. "Axial Compression Test of RC Columns Consolidation with BFRP." Applied Mechanics and Materials 166-169 (May 2012): 881–84. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.881.
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12 RC columns were made, including nine RC columns wrapped with BFRP, three RC columns without any reinforcement, to conduct the comparative study of axial compression. The result shows that the bearing capacity of the RC columns reinforced with the fibers increases obviously.The displacement ductility factor increases, but its increase rate becomes slow with increasing layers of fiber cloth, so the most economical layer number is 3. Based on the confinement mechanism of FRP cloth and the calculation formula of the bearing capacity for common RC column, the formula of the bearing capacity for reinforced RC column with BFRP cloth is proposed. The result of calculation basically tallies with the number in experiment.
4
Zhu, Lei, Qing Feng Xu, Xiang Min Li, and Chun Ming Zhu. "Experimental Studies of Reinforced Concrete Column Capacity Affected by Core Drilling." Advanced Materials Research 133-134 (October 2010): 1195–200. http://dx.doi.org/10.4028/www.scientific.net/amr.133-134.1195.
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The paper presents the experimental studies of reinforced concrete column (RC column) capacity affected by core drilling. By testing three groups (9 total) of full scale concrete short columns, the experiment demonstrates that the axial compression capacity of RC columns after core drilling is reduced from 5.63% to 22.14% while the ultimate displacement decreases from 1.88% to 26.14%. The behavior of columns is altered from the axial compression failure to a small-eccentricity compression failure. The paper summarizes experiment results, followed by an investigation of the dominant factors, such as column effective cross section, drilling location, drilled hole repairing and reinforcing steels discontinued by drilling, that have impact on RC column capacity. The rationale of capacity variations of RC columns due to core drilling is also investigated.
5
Li, Kai Wen, Zhi Yang Li, Xin Wan, and Fei Liu. "Non-Linear Numerical Simulation on Hysteretic Behavior of SRC Columns." Applied Mechanics and Materials 723 (January 2015): 382–86. http://dx.doi.org/10.4028/www.scientific.net/amm.723.382.
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In order to study the mechanics properties to of concrete columns with embedded steel, two groups contrasting analysis models referring to SRC column and RC column are established by using finite element software ABAQUS. Both Static and cycle force are conducted. Analytical results show that bearing capacity and deformation ability of steel embedded reinforced concrete columns (SRC) under static loading are obviously higher than those of the reinforced concrete column (RC). Under the cycle force, the hysteresis circles of the SRC columns are fuller than RC column. The capability of energy consumption of the SRC columns is almost 1.4 times more than the RC columns. Further axial pressure coefficient and stirrup ratio are considered as parameters to study hysteresis characteristics, energy dissipation and the influence of the skeleton curve of SRC columns. The analytical results demonstrate that the hysteresis characteristics and energy dissipationare different with the changes of axial pressure coefficient. Meanwhile, the stirrup ratio of SRC column has little effect on energy dissipation. The study results have some value on the design and application of the SRC columns.
6
Lei, Zi Xue, Yu Hang Han, San Sheng Dong, and Jun Qing Guo. "Analysis of Seismic Performance of RC Frames with Centrally Reinforced Columns." Advanced Materials Research 671-674 (March 2013): 1319–23. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.1319.
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A centrally reinforced column is a new type of RC columns, formed by providing a reinforcement skeleton at the central part of the cross section of an ordinary RC column. Tests have shown that as compared with an ordinary RC column, this type of columns has a higher load carrying capacity and ductility. From the pushover analysis of a frame composed of ordinary RC columns and one consisting of centrally reinforced columns, their seismic performance under seismic load of 9-degree intensity was studied according to Chinese code, including target displacements, story-level displacements, interstory drifts, appearance and development of plastic hinges. The results indicate that although the dimensions of cross sections of columns in the frame with centrally reinforced columns are smaller than those of the ordinary frame, the former still has a higher overall load carrying capacity and seismic performance than the latter.
7
Ge, Xiao, Matthew S. Dietz, Nicholas A. Alexander, and Mohammad M. Kashani. "Nonlinear dynamic behaviour of severely corroded reinforced concrete columns: shaking table study." Bulletin of Earthquake Engineering 18, no. 4 (November 8, 2019): 1417–43. http://dx.doi.org/10.1007/s10518-019-00749-3.
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Abstract A set of benchmark, medium scale, shaking table tests on corroded reinforced concrete (RC) columns is conducted with the aim of investigating the effects of corrosion damage on the nonlinear dynamic behaviour of RC bridge piers. The experimental programme consists of an uncorroded control specimen and two corroded RC column specimens, with identical structural details. An accelerated corrosion procedure is used to corrode the RC columns. The uncorroded and corroded specimens are subjected to far-field long duration ground motion excitations. The two corroded columns had 51% and 65% average mass loss ratios. The testing sequence includes slight, extensive, and complete damage levels, followed by an aftershock to examine the cascade effect on the nonlinear dynamic response of the proposed RC columns. The experimental results show that corrosion changes the failure mode of the RC columns, and has a significant negative impact on the residual strength (about 50% mass loss results in about 80% strength reduction) and drift capacity of RC columns.
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Han, Sang Whan, Chang Seok Lee, Mary Ann Paz Zambrana, and Kihak Lee. "Calibration Factor for ASCE 41-17 Modeling Parameters for Stocky Rectangular RC Columns." Applied Sciences 9, no. 23 (November 29, 2019): 5193. http://dx.doi.org/10.3390/app9235193.
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Existing old reinforced concrete (RC) buildings could be vulnerable to large earthquake events. Most columns in such buildings have insufficient reinforcement details, which may experience failure during an early loading stage. The failure of columns may lead to partial or complete collapse of entire building systems. To prepare for an adequate retrofit plan for columns, it is necessary to simulate the cyclic behavior of columns using a numerical model with adequate values of constituent modeling parameters. The nonlinear component modeling parameters are specified in ASCE 41-17. However, the experiments on stocky RC columns suggest that ASCE 41-17 nonlinear component modeling parameters do not reflect the RC column behavior adequately. To accurately simulate the nonlinear load–deformation responses of stocky RC columns with low span-to-depth ratio, this study proposes a calibration factor for ASCE 41-17 RC column modeling parameters. For this purpose, this study collected test data of 47 stocky column specimens. Based on the test data, empirical equations including the calibration factor for modeling parameters “a” and “b” in ASCE 41-17 were proposed. The accuracy of the proposed equation was verified by comparing the measured and calculated envelope curves.
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Landović, Aleksandar, and Miroslav Bešević. "Experimental Research on Reinforced Concrete Columns Strengthened with Steel Jacket and Concrete Infill." Applied Sciences 11, no. 9 (April 29, 2021): 4043. http://dx.doi.org/10.3390/app11094043.
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Experimental research on axially compressed columns made from reinforced concrete (RC) and RC columns strengthened with a steel jacket and additional fill concrete is presented in this paper. A premade squared cross-section RC column was placed inside a steel tube, and then the space between the column and the tube was filled with additional concrete. A total of fourteen stub axially compressed columns, including nine strengthened specimens and five plain reinforced concrete specimens, were experimentally tested. The main parameter that was varied in the experiment was the compressive strength of the filler concrete. Three different concrete compression strength classes were used. Test results showed that all three cross-section parts (the core column, the fill, and the steel jacket) worked together in the force-carrying process through all load levels, even if only the basic RC column was loaded. The strengthened columns exhibited pronounced ductile behavior compared to the plain RC columns. The influence of the test parameters on the axial compressive strength was investigated. In addition, the specimen failure modes, strain development, and load vs. deformation relations were registered. The applicability of three different design codes to predict the axial bearing capacity of the strengthened columns was also investigated.
10
Li, Jian Hui, Ying Li, and Zong Cai Deng. "Envelope Response of Corroded RC Circular Columns Strengthened with Hybrid Fiber Reinforced Polymers." Advanced Materials Research 255-260 (May 2011): 3124–28. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.3124.
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Corroded RC columns do not possess necessary ductility to dissipate seismic energy during a major earthquake, the study investigates the use of hybrid fiber reinforced polymer (FRP) wrapping as a method of retrofitting non-ductile corroded RC columns, and a model to determine the envelope response of RC corroded columns strengthened with hybrid FRP are presented based on cross-section analysis for undamaged RC element. The results show that the technique of strengthening corroded RC column with hybrid FRP is quite effective, the envelope curve estimated using the linear plane assumption with modification by reinforcement slip model, may still be used as the envelope curve of RC corroded columns strengthened with hybrid FRP, a good agreement between analytical and experimental results is observed.
11
Weng, Jian, Kang Hai Tan, and Chi King Lee. "Identifying Buckling Resistance of Reinforced Concrete Columns During Inelastic Deformation." International Journal of Structural Stability and Dynamics 20, no. 03 (January 23, 2020): 2050029. http://dx.doi.org/10.1142/s0219455420500297.
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A simple solution method to identify buckling resistance of reinforced concrete (RC) columns during inelastic deformation is presented. Unlike conventional buckling solution methods, this proposed method predicts inelastic buckling loads of RC columns by directly solving the equilibrium differential equation under buckling. The method considers specific deflection configuration, end restraint conditions and inelastic material properties of the deformed column. In order to evaluate the reliability and accuracy of the proposed method, the results obtained from the purposed method are compared with the test results of eccentrically loaded RC columns. In addition, by using the proposed solution procedure, a parametric study is conducted to investigate the effects of critical RC column design parameters on column buckling behavior and resistance, including slenderness ratio, concrete strength, as well as longitudinal reinforcement and stirrup ratios. The results of the parametric study show that the proposed method is rational and can be adopted to effectively identify buckling resistance of RC columns subjected to inelastic damage, especially when load redistributions have occurred in the structure during progressive collapse.
12
Shan, Zhiwei, Lijie Chen, Kun Liang, Ray Kai Leung Su, and Zhaodong Xu. "Strengthening Design of RC Columns with Direct Fastening Steel Jackets." Applied Sciences 11, no. 8 (April 18, 2021): 3649. http://dx.doi.org/10.3390/app11083649.
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For non-seismically designed columns with insufficient strength and flexural stiffness, intense inter-story drift can be incurred during a strong earthquake event, potentially leading to the collapse of the entire building. Existing strengthening methods mainly focus on enhancing axial or flexural strength but not the flexural stiffness of columns. In response, a novel direct fastening steel jackets that can increase both flexural strength and stiffness is introduced. This novel strengthening method features straightforward installation and swift strengthening as direct fastening is used to connect steel plates together to form a steel jacketed column. This new connection method can quickly and stably connect two steel components together by driving high strength fasteners into them. In this paper, the design procedure of RC columns strengthened with this novel strengthening method is originally proposed, which includes five steps: (1) estimating lateral load capacity of damaged RC columns; (2) determining connection spacing of steel jacket; (3) estimating the lateral load capacity of strengthened RC column; (4) evaluating the axial load ratio (ALR) of strengthened RC columns; and (5) estimating effective stiffness of strengthened RC columns. Lastly, an example is presented to illustrate the application of the proposed design procedure.
13
Zhao, Wei Feng, Xiao Quan Hu, and Qin Chen. "Shear Resistant Behavior of RC Columns Subjected to Axial Pulse-Like Ground Motions." Advanced Materials Research 639-640 (January 2013): 832–35. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.832.
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The shear-resistant behavior of reinforced concrete (RC) columns subjected to axial velocity pulse-like ground motions was studied. Single RC columns with the constant vertical and horizontal fundamental period were used to investigate the influences of fault-distance of earthquake records, vertical to horizontal acceleration spectral ratio of earthquake records, initial axial load ratio and shear span ratio of RC column, on the shear-resistant behavior of RC columns. a suite of 18 strong ground motion records from Chi-chi earthquake divided into three fault-distance groups were taken as excitations to execute nonlinear dynamic time history analysis. The results demonstrated that axial velocity pulse-like earthquake action (fault-distance) had significant influences on the shear resistant-resistant of RC columns. Shear-resistant behavior (shear capacity/shear demand) increases with the increasing of fault-distance. Fault-distance and shear span ratio had a certain coupling influences on the shear-resistant behavior of RC columns.
14
Xie, Yong Ping, Lei Jia, and Gang Sun. "Review on Seismic Behavior of RC Columns." Applied Mechanics and Materials 353-356 (August 2013): 2092–96. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.2092.
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Column is the key member of the seismic structures, after the earthquake destroyed, not only cause column serious economic damage, and will cause a large number of casualties. For studying the seismic behavior and size effect of full-scale reinforced concrete columns. A comprehensive summary of the experimental results is undertaken to evaluate the seismic behavior of RC concrete columns, including test equipment and load method and mode of failure and Seismic behavior. It is concluded that the ductility and shear capacity of RC mainly depends on shear span ratio, axial load ratio and stirrup ratio. But the seismic behavior of large scale RC columns has no systematic studied.
15
Deng, Mingke, and Yangxi Zhang. "Seismic Performance of High-Ductile Fiber-Reinforced Concrete Short Columns." Advances in Civil Engineering 2018 (2018): 1–11. http://dx.doi.org/10.1155/2018/3542496.
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This study mainly aims to investigate the effectiveness of high-ductile fiber-reinforced concrete (HDC) as a means to enhance the seismic performance of short columns. Six HDC short columns and one reinforced concrete (RC) short column were designed and tested under lateral cyclic loading. The influence of the material type (concrete or HDC), axial load, stirrup ratio, and shear span ratio on crack patterns, hysteresis behavior, shear strength, deformation capacity, energy dissipation, and stiffness degradation was presented and discussed, respectively. The test results show that the RC short column failed in brittle shear with poor energy dissipation, while using HDC to replace concrete can effectively improve the seismic behavior of the short columns. Compared with the RC short column, the shear strength of HDC specimens was improved by 12.6–30.2%, and the drift ratio and the energy dissipation increases were 56.9–88.5% and 237.7–336.7%, respectively, at the ultimate displacement. Additionally, the prediction model of the shear strength for RC columns based on GB50010-2010 (Chinese code) can be safely adopted to evaluate the shear strength of HDC short columns.
16
Nicolae, Marilena. "Complex Systems of Distillation Columns Used in the Production of the Propylene Oxide." Revista de Chimie 68, no. 1 (February 15, 2017): 28–34. http://dx.doi.org/10.37358/rc.17.1.5382.
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Complex systems of distillation columns were intensively studied within last decades and continue to show interest for researchers and for industrial application. The first designed complex distillation column with heat integration was the Petlyuk column and the development of complex systems of columns continued up to dividing wall columns (DWC) which are increasingly being used in industry. DWC are usually used to separate three products, components or fractions, from a multicomponent mixture. This study attempts to find the best fitting of complex systems of columns in the process of propylene oxide (PO) obtaining using the method of propylene chlorination and presents a proposed variant of separation which can lead to a reduced energy consumption. The fabrication of PO through this method lead to a multicomponent mixture which is separated in two main products: propylene oxide (PO) and heavier components containing as valuable compound 1,2 dichloropropane (DCP). Both products, PO and DCP, have important uses in the chemical industry. The study of complex schemes of columns used for PO separation was assessed by simulation using a simplified method based on Fenske � Underwood - Gilliland correlation (F.U.G.) [1]. The systems studied in this work include the following configurations of columns: column with prefractionator, column with partially coupled prefractionator, the Petlyuk column, the dividing wall column, column with side striper, column with side rectifier, the direct and the indirect sequence.
17
Zhou, Ying Wu, Ling Yi Wu, Li Li Sui, and Feng Xing. "Experimental Studies on the Mechanical Performances of Corroded Reinforced Concrete Columns Retrofitted with FRP." Applied Mechanics and Materials 405-408 (September 2013): 726–30. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.726.
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Due to the superiority of high corrosion resistance of FRP materials, more and more attentions have been attracted to the retrofitting of corroded reinforced concrete (RC) columns with FRP. This paper thus presents an experimental study on mechanical performances of corroded RC columns strengthened with FRP, focusing on the effects of different corrosion rates of the reinforcements and the retrofitting scheme. The effectiveness of externally bonded FRP to the corroded RC column to increase its load capacity and ductility is tested; the mechanical performances of the strengthened columns are theoretically investigated. The results indicate that the effectiveness of retrofitting the existing corroded RC columns with FRP jackets is much more significant than that of retrofitting the newly built columns with FRP jackets and externally wrapped with FRP jackets is much more effective to improving the structural performances of heavily corroded columns.
18
Campione, G., M. Fossetti, C. Giacchino, and G. Minafò. "RC columns externally strengthened with RC jackets." Materials and Structures 47, no. 10 (July 19, 2013): 1715–28. http://dx.doi.org/10.1617/s11527-013-0146-x.
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Wan, Hai Tao, and Peng Li. "Test Research on Seismic Performance of Column." Applied Mechanics and Materials 166-169 (May 2012): 1058–61. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1058.
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Reinforced concrete (RC) column component is a very important lateral force-resisting member which is widely used in China. Its seismic behavior has a great impact on the seismic performance of the overall structure. Damage of some reinforced concrete frame structures under the earthquake is caused by the damage of columns, So RC columns are an essential seismic members. The paper introduces the design of RC column specimen, mechanical properties of materials, production of RC column specimen, test method, loading device, loading system, the contents of measurement and data acquisition in detail. From the above analysis, it is obvious that the test is the most effective means of studying the seismic performance of column.
20
Zou, You Lin, and Pei Yan Huang. "Experimental Investigation for Horizontal Ultimate Bearing Capacity and Target Ductility Factor Improvement Results of the RC Column Reinforced by AFL with Damages." Applied Mechanics and Materials 488-489 (January 2014): 497–500. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.497.
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Deem test results from the low reversed cyclic loading quasi-static test with 2 RC columns as the basic information of secant stiffness damage of the reference column and take use of the TMS instrument in the test to artificially make the damage percentage of secant stiffness of the RC column as 33%, 50% and 66%, 6 damaged columns in total; reinforce the 6 damaged columns and 2 undamaged ones under the same conditions with AFL, through quasi-static contrast test. Test results show that it is able to effectively boost horizontal ultimate bearing capacity and ductility deformability of the RC columns with AFL for reinforcement; besides, there is a linear function relationship between horizontal ultimate bearing capacity, target ductility factor, and damage percentage of secant stiffness.
21
Kim, Hyeong-Gook, Chan-Yu Jeong, Dong-Hwan Kim, and Kil-Hee Kim. "Confinement Effect of Reinforced Concrete Columns with Rectangular and Octagon-Shaped Spirals." Sustainability 12, no. 19 (September 26, 2020): 7981. http://dx.doi.org/10.3390/su12197981.
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Conventional spiral-type transverse reinforcement is effective at increasing the ductility and the maximum strength of reinforced concrete (RC) columns because it confines the inner concrete and the longitudinal reinforcement. However, when arranging crossties in a RC column with spirals, problems such as mutual interference with longitudinal reinforcement, overcrowding of reinforcement, and deterioration of constructability occur. Furthermore, the loosening of 90 and 130-degree standard hooks due to the lateral expansion of concrete causes buckling of the longitudinal reinforcement. This paper describes the ability of a newly developed spiral-type transverse reinforcement with various yield strengths to confine RC columns subjected to cyclic lateral load and constant axial load. The ductility capacity, energy dissipation, and effective stiffness of RC columns confined by the developed spiral-type transverse reinforcement were compared with those of RC columns confined by typical rectangular reinforcement. The experimental results showed that RC column specimens with the developed spiral-type transverse reinforcement have better performances in terms of ductility capacity and energy dissipation, even though the amount of reinforcement used for the specimens decreased by about 27% compared with the specimen with typical rectangular reinforcement.
22
Zhou, Chunli, Xiaowei Li, Dongbo Wang, and Shunxiang Xia. "Analysis of Bearing Capacity and Seismic Performance of Circular RC Columns Strengthened with Externally Wrapped Steel Plates." Advances in Civil Engineering 2019 (August 26, 2019): 1–17. http://dx.doi.org/10.1155/2019/2515091.
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Based on a practical project, the construction method of circular reinforced concrete (RC) columns strengthened with externally wrapped steel plates was introduced in this paper. In order to study the bearing capacity and seismic performance of circular RC columns after strengthening, a formula for calculating the bearing capacity of circular RC columns strengthened with externally wrapped steel plates was derived, with reference to the Code for Design of Strengthening Concrete Structure. Through ABAQUS software, the vertical monotone static loading analysis and the horizontal low-cyclic reversed loading analysis were carried out, respectively, before and after the strengthening of the full-size RC columns in this project. The results showed that the bearing capacity of the normal section of the RC column after strengthening was about 80% higher than that before strengthening, and the results of FEM software were in accord with the calculation results of theoretical formula to some degree. Under horizontal low-cyclic reversed loading, the columns after strengthening had both plumper hysteresis curves and higher ductility factors and equivalent viscous damping coefficient than those before strengthening, indicating the energy dissipation capacity, plastic deformation capacity, and seismic performance of the RC columns after strengthening were all obviously improved.
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Guo, Kun, Qirui Guo, and Yuanfeng Wang. "Effect of Bond-Slip on Dynamic Response of FRP-Confined RC Columns with Non-Linear Damping." Applied Sciences 11, no. 5 (February 27, 2021): 2124. http://dx.doi.org/10.3390/app11052124.
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As a composite material, the damping energy consumption mechanism of fiber reinforced polymer-confined reinforced concrete (FRP-C RC) structure is very complex. In previous dynamic calculation models, the bond-slip effect for steel bars was often ignored, which would lead to a considerable error in the response of the FRP-C RC structures. In this paper, a new numerical model of FRP-C RC columns considering the bond-slip for steel bars is established using a zero-length element and nonlinear beam-column elements in the OpenSees software, and the results of the model are verified by experimental results. Based on the complex damping theory, the loss factor expression and nonlinear damping model of FRP-C RC columns with the bond slip effect are proposed. Finally, the dynamic response of FRP-C RC columns with nonlinear damping under harmonic load is calculated and compared with the results available in literature. The results show that the proposed model considering steel bars’ bond-slip can provide better prediction for dynamic response of FRP-C RC columns and make the future seismic design of FRP-C RC columns safer.
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Zhou, Miao, Jian Wei Li, and Jing Min Duan. "Experimental Study on the Axial Loading Tests of RC Columns Strengthened with Steel Tube." Applied Mechanics and Materials 204-208 (October 2012): 2878–82. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.2878.
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This paper carries out a series of experimental study on 6 column specimens, analyses and compares with the different parameters on the axial loading tests of RC columns and RC columns strengthened with steel tube. The experimental results show that the RC columns strengthened with steel tube take full advantage of loading properties of both materials, thus greatly improve the bearing capacity of specimens. With the same wall thickness steel tube, the improving degree of bearing capacity of long columns is bigger than the short columns, and the reinforcement effect is more obvious. The experimental results can offer reference for scientific research and engineering staff, and promote this reinforcement method to be widely used in engineering practice.
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Hyun, Jung-Hwan, Jin-Wook Bang, Bang-Yeon Lee, and Yun-Yong Kim. "Effects of the Replacement Length of Concrete with ECC on the Cyclic Behavior of Reinforced Concrete Columns." Materials 14, no. 13 (June 25, 2021): 3542. http://dx.doi.org/10.3390/ma14133542.
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This paper presents an experimental investigation on the effects of the replacement length of concrete with engineered cementitious composites (ECC) on the cyclic behavior of a reinforced concrete (RC) column. A conventional RC column specimen and two RC composite columns designed with ECC were fabricated. To investigate the cyclic behavior of each specimen, a series of cyclic loading tests was performed under a reversed cyclic loading condition with a constant axial load. Test results showed that ECC columns exhibited higher cyclic behavior in terms of load carrying capacity, ductility, and energy dissipation capacity compared to the RC column. It was also found that when applying ECC to the column specimen with a length of 3.6d or more, the energy dissipation capacity was greatly increased.
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Zheng, Jian Lan, and Wei Fan. "Experimental Investigation of the RC Columns Strengthened with Outer Closed SCC under Cyclic Loadings." Advanced Materials Research 446-449 (January 2012): 728–32. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.728.
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Experiment research for aseismic performance of RC Column strengthened by self-compacting concrete under second force is completed. By comparing three comparison columns and three columns strengthened by self-compacting concrete in low-cycle reciprocating horizontal loads seismic performance test, the specimen described the typical features of breakage, and the hysteresis and ductility of the RC column reinforced or not by self-compacting concrete is analyzed, the reinforcement effect by the different initial force is compared. The results show that: reinforcement by increasing the cross-section of self-compacting concrete is an effective method to significantly improve the shear strength of reinforced concrete columns and specimen ductility. The presence of the initial force have impact on reinforcing effect of RC columns, the greater the initial force, the more obvious impact.
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Song, Kun, and Zhen Bao Li. "Seismic Behavior of RC Columns With Corner Focus Longitudinal Bars." Applied Mechanics and Materials 470 (December 2013): 876–79. http://dx.doi.org/10.4028/www.scientific.net/amm.470.876.
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Many frame structures were damaged for the column hinge mechanism in the Wenchuan earthquake because of the biaxial seismic action. Four reinforced concrete columns with corner focus longitudinal bars were tested to improve the seismic behavior of RC columns subjected to multiaxial loading. The hysteretic behavior, skeleton curves and feature points were discussed. The results indicate that the method can improve seismic behavior of RC columns
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Du, Chuang, Xi Kang Yan, and Hai Long Zhao. "The Finite Element Model Improvement on Shear Behavior of RC Frame Columns under Lateral Bevel Load." Advanced Materials Research 468-471 (February 2012): 2609–12. http://dx.doi.org/10.4028/www.scientific.net/amr.468-471.2609.
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The finite element models of biaxial shear capacity of RC frame columns are investigated.The calculation results and experimental results are compared using the different models.It is shown that different finite element models are effectively used to simulate the RC frame column. However, the simplified model may save computer time and be more convenient for the numerical simulation. Finally, the bilateral shear correlation of RC frame column is investigated using the simplified model. The results indicate that the bilateral shear correlation of the RC frame columns with different quantity of stirrups in two directions accords with the ellipse law and the fitting formula is presented.
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Lin, Xuchuan, and Xinzheng Lu. "Numerical Models to Predict the Collapse Behavior of RC Columns and Frames." Open Civil Engineering Journal 11, no. 1 (November 17, 2017): 854–60. http://dx.doi.org/10.2174/1874149501711010854.
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Introduction: Blind analysis contests for predicting the results of several collapse tests on RC frame structure, were carried out by the Collapse Prevention Committee of Architectural Society of China in 2011. This paper presents the adopted numerical models for the collapse simulations of four RC column tests and one RC frame test. Methods: The columns and beams in the RC frame were modeled by beam elements using the fiber model of THUFIBER program. The confined effect of the stirrups in the square RC column was taken into account by using the backbone curve of confined concrete. The methods to determine the key parameters of the adopted model were introduced. Results and Conclusion: The prediction results were compared with the test results, and the adopted models exhibited good predictions for the general behavior of both the RC columns and frame. The model was proposed for investigating the collapse mechanism of RC frames.
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Zou, You Lin, and Pei Yan Huang. "Experimental Investigation for Secant Stiffness and Energy-Dissipating Capacity Improvement Results of the RC Column Reinforced by AFL." Applied Mechanics and Materials 488-489 (January 2014): 501–4. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.501.
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Select CA-0-J-1 of RC column reinforced by AFL, and un-reinforced CA-0-1 of RC column, respectively perform the low reversed cyclic loading quasi-static contrast test; collate data of experimental results about these two columns, analyze the changes such as fracture morphology, bearing capacity, secant stiffness and energy-dissipating capacity damage of RC columns before and after reinforcement, adopt calculation and Origin software to fit mathematical equations and work out functional relationships between secant stiffness and lateral rate, as well as between energy-dissipating capacity and lateral displacement rate.
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Rousakis, Theodoros, Evgenia Anagnostou, and Theodora Fanaradelli. "Advanced Composite Retrofit of RC Columns and Frames with Prior Damages—Pseudodynamic Finite Element Analyses and Design Approaches." Fibers 9, no. 9 (September 6, 2021): 56. http://dx.doi.org/10.3390/fib9090056.
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This study develops three-dimensional (3D) finite element (FE) models of composite retrofits in deficient reinforced concrete (RC) columns and frames. The aim is to investigate critical cases of RC columns with inadequate lap splices of bars or corroded steel reinforcements and the beneficial effects of external FRP jacketing to avoid their premature failure and structural collapse. Similarly, the RC-frame FE models explore the effects of an innovative intervention that includes an orthoblock brick infill wall and an advanced seismic joint made of highly deformable polymer at the boundary interface with the RC frame. The experimental validation of the technique in RC frames is presented in earlier published papers by the authors (as well as for a four-column structure), revealing the potential to extend the contribution of the infills at high displacement ductility levels of the frames, while exhibiting limited infill damages. The analytical results of the advanced FE models of RC columns and frames compare well with the available experimental results. Therefore, this study’s research extends to critical cases of FE models of RC frames with inadequate lap splices or corroded steel reinforcements, without or with brick wall infills with seismic joints. The advanced pseudodynamic analyses reveal that for different reinforcement detailing of RC columns, the effects of inadequate lap-spliced bars may be more detrimental in isolated RC columns than in RC frames. It seems that in RC frames, additional critical regions without lap splices are engaged and redistribution of damage is observed. The detrimental effects of corroded steel bars are somewhat greater in bare RC frames than in isolated RC columns, as all reinforcements in the frame are considered corroded. Further, all critical cases of RC frames with prior damages at risk of collapse may receive the innovative composite retrofit and achieve higher base shear load than the original RC frame without corroded or lap-spliced bars, at comparable top displacement ductility. Finally, the FE analyses are utilized to propose modified design equations for the shear strength and chord rotation in cases of failure of columns with deficiencies or prior damages in RC structures.
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Li, Yeou-Fong, Yan-Jie Lin, Cheng-Wei Chen, and Chih-Tsung Lin. "Theoretical and experimental studies on repaired and rehabilitated reinforced concrete frames." Canadian Journal of Civil Engineering 34, no. 8 (August 1, 2007): 923–33. http://dx.doi.org/10.1139/l07-012.
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In this paper, an effective repair and rehabilitation working method is proposed for moderately damaged reinforced concrete (RC) building structures after major earthquakes. Three RC frames with nil, half-height, and full-height brick walls are designed and tested at the National Center for Research on Earthquake Engineering (NCREE), Taiwan. After the columns of these nonductile RC frames are damaged, steel wire cables with nonshrinkage mortar are used to repair the damaged columns, and carbon fiber reinforced polymers (CFRP) are used to rehabilitate the damaged columns. A stress–strain relationship of the confined concrete is used in the theoretical sectional analysis. The columns are confined by steel wires and CFRP, and the "equivalent column model" is proposed in this paper and used to analyze the brick walls inside the RC frames. The analytical results can reasonably predict the lateral force–displacement relationships of these RC frames. Key words: nonductile frame, carbon fiber reinforced polymers, steel wire cable, repair, rehabilitation.
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Park, Jong Wook, Sang A. Cha, Ji Eun Kang, Mohamad Mansour, and Jung Yoon Lee. "Axial Strain of Reinforced Concrete Columns." Advanced Materials Research 163-167 (December 2010): 1858–61. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1858.
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The reinforced concrete members are designed to fail in flexural member to behave ductilely. Also the failure doesn’t impose on columns but beams. But according to the plastic collapse mechanism, the plastic hinge potentially developed at the bottom of the RC column near the base of the structure after flexural yielding. These columns are generally dominated by shear which led to sudden failure in post yielding region because of its relatively short span-to-depth ratio, so special care is needed. The deformability of column with short span-to-depth ratio is small compared with larger span-to-depth ratio column under reversed cyclic loading. Therefore the design of these kinds of RC columns necessitates the prediction of both the shear strength after flexural yielding and corresponding ductility of such members. Ten RC columns with varying axial force ratio and shear reinforcement ratio were tested under monotonic and reversed cyclic loading. The most affectable factor to column behavior was the axial force. The result indicates that concrete contribution to shear resistance in the plastic hinge region and axial strain were decreased as axial force.
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Megalooikonomou, Konstantinos G. "PHAETHON: Software for Analysis of Shear-Critical Reinforced Concrete Columns." Modern Applied Science 12, no. 3 (February 7, 2018): 1. http://dx.doi.org/10.5539/mas.v12n3p1.
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Earthquake collapse of substandard reinforced concrete (RC) buildings, designed and constructed before the development of modern seismic design Codes, has triggered intense efforts by the scientific community for accurate assessment of this building stock. Most of the proposed procedures for the prediction of building strength and deformation indices were validated by assembling databases of RC column specimens tested under axial load and reversed cyclic lateral drift histories. Usually a column structural behavior is assessed by considering all involving mechanisms of behavior, namely flexure with or without the presence of axial load, shear and anchorage. In the present paper a force-based fiber beam/column element was developed accounting for shear and tension stiffening effects in order to provide an analytical test-bed for simulation of experimental cases such as the lightly reinforced columns forced to collapse. Their peculiar characteristics are the outcome of the shear – flexure interaction mechanism modeled here based on the Modified Compression Field Theory (MCFT) and the significant contribution of the tensile reinforcement pullout from its anchorage to the total column’s lateral drift. These features are embedded in this first-proposed stand-alone Windows program named “Phaethon” -with user’s interface written in C++ programming language code- aiming to facilitate engineers in executing analyses both for rectangular and circular substandard RC columns.
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Lampropoulos, A. P., and S. E. Dritsos. "Modeling of RC columns strengthened with RC jackets." Earthquake Engineering & Structural Dynamics 40, no. 15 (April 29, 2011): 1689–705. http://dx.doi.org/10.1002/eqe.1109.
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Zaneeb, Aysha M., Rupen Goswami, and C. V. R. Murty. "Lateral shear strength of rectangular RC columns subjected to combined P-V-M monotonic loading." Bulletin of the New Zealand Society for Earthquake Engineering 53, no. 4 (December 1, 2020): 227–41. http://dx.doi.org/10.5459/bnzsee.53.4.227-241.
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An analytical method is presented to estimate lateral shear strength (and identify likely mode and location of failure) in reinforced concrete (RC) cantilever columns of rectangular cross-section under combined axial force, shear force and bending moment. Change in shear capacity of concrete with flexural demand at a section is captured explicitly and the shear resistance offered by concrete estimated; this is combined with shear resistance offered by transverse and longitudinal reinforcement bars to estimate the overall shear capacity of RC columns. Shear–moment (V-M) interaction capacity diagram of an RC column, viewed alongside the demand diagram, identifies the lateral shear strength and failure mode. These analytical estimates compare well with test data of 107 RC columns published in literature; the test data corresponds to different axial loads, transverse reinforcement ratios, longitudinal reinforcement ratios, shear span to depth ratios, and loading conditions. Also, the analytical estimates are compared with those obtained using other analytical methods reported in literature; in all cases, the proposed method gives reasonable accuracy when estimating shear capacity of RC columns. In addition, the method provides insights into the shear resistance mechanism in RC columns under the combined action of P-V-M, and it is simple to use.
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Zhang, Qin, Zong-yan Wei, Jin-xin Gong, Ping Yu, and Yan-qing Zhang. "Equivalent Viscous Damping Ratio Model for Flexure Critical Reinforced Concrete Columns." Advances in Civil Engineering 2018 (July 15, 2018): 1–15. http://dx.doi.org/10.1155/2018/5897620.
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In order to determine the energy dissipation capacity of flexure critical reinforced concrete (RC) columns reasonably, an expression for describing the hysteretic behavior including loading and unloading characteristics of flexure critical RC columns is presented, and then, a new equivalent viscous damping (EVD) ratio model including its simplified format, which is interpreted as a function of a displacement ductility factor and a ratio of secant stiffness to yield stiffness of columns, is developed based on the proposed hysteretic loop expression and experimental data from the PEER column database. To illustrate the application of the proposed equivalent damping ratio model, a case study of pushover analysis on a flexure critical RC bridge with a single-column pier is provided. The analytical results are also compared with the results obtained by other models, which indicate that the proposed model is more general and rational in predicting energy dissipation capacity of flexure critical RC structures subjected to earthquake excitations.
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Abay, Abreha, and Temesgen Wondimu. "Numerical Investigation of Bundled RC Column under Impact Load." Advances in Civil Engineering 2021 (August 23, 2021): 1–18. http://dx.doi.org/10.1155/2021/5587576.
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Dynamic impact load has an extensive application area in civil engineering, including highway, military, and marine structures. Many researchers have studied the performance of reinforced concrete (RC) columns under impact load. However, very limited work has been conducted on the effect of bundle reinforced concrete (BRC) columns subjected to lateral impact load. In this study, to examine the behavior of RC columns under impact load, numerical simulations of one with normal reinforcement distribution and three different bundles of reinforced concrete column specimens have been conducted using an explicit finite element (FE) analysis. In addition to the bundle reinforcement distribution, the parameters considered in the study are impact scenarios, impact velocity, pure axial load, and impact locations. From the numerical analysis, it has been found that bundling of longitudinal reinforcement does not only improve the impact capacity but also stabilizes the fluctuating response of impacted reinforced concrete columns. Both peak impact force and maximum lateral displacements of impacted BRC columns increase with increasing initial impact velocity. The numerical results also show that pure axial load slightly improved the impact capacity of the BRC columns. Finally, while the global failure of the RC column governs the response of repeatedly impacted BRC columns, failure characteristics of the single impacted columns are associated with local concrete damage at the impact zone.
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Xing, Guohua, Osman E. Ozbulut, Mohammed Ali Al-Dhabyani, Zhaoqun Chang, and Sherif M. Daghash. "Enhancing flexural capacity of RC columns through near surface mounted SMA and CFRP bars." Journal of Composite Materials 54, no. 29 (June 27, 2020): 4661–76. http://dx.doi.org/10.1177/0021998320937054.
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This study explores the flexural behavior of reinforced concrete (RC) columns strengthened with near surface mounted (NSM) shape memory alloy (SMA) bars or carbon fiber reinforced polymer (CFRP) bars. Seven RC column specimens were designed and fabricated to study the influence of different variables on the flexural response of the strengthened columns. These parameters include type of NSM reinforcement (SMA bars or CFRP bars), ratio of NSM reinforcement, and effect of CFRP jacketing. The columns were tested under cyclic lateral loading with constant axial force. The flexural behavior of each specimen was examined in terms of peak load, failure load, drift ratios, displacement ductility, stiffness degradation, energy dissipation, and seismic damage index. The experimental results indicate that strengthening of RC columns with NSM SMA or CFRP bars improves the flexural behavior of the columns through increasing the lateral load capacity, reducing the stiffness degradation and increasing the cumulative energy absorption up to failure. Further enhancement in the lateral response of RC columns was obtained by combining NSM bars and CFRP jacketing as the later provides an additional confinement to the critical sections of the test specimens.
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Navdar, M. Burhan, and Naci Caglar. "Numerical Investigation of Behavior of RC Columns Strengtheneg with RC Jacket." Academic Perspective Procedia 2, no. 2 (October 27, 2019): 257–64. http://dx.doi.org/10.33793/acperpro.02.02.39.
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Strengthening of structural elements which are insufficient in terms of earthquake performance is very important for the safety of existing structures. Nowadays, one of the most commonly used methods is strengthening such members with RC jacketing. Several experimental studies have been conducted in the literature to investigate behavior of structural elements reinforced with RC jacketing. Moreover, numerical studies are frequently preferred due to the high cost of experimental studies and the limited availability of laboratory facilities. In this study, a finite element model has been created with OpenSees program in order to investigate the behavior of strengthened RC columns with jacketing. Later, the accuracy of the model has been verified successful by the experimental results selected from the literature. By using that verified model, the effects of concrete strength and amount of spacing of transverse reinforcement used on the jacketing part on reinforced column behavior were investigated. As a result of the study, it is deduced that the change in the concrete strength and amount of transverse reinforcement results in a significant change in ductility, load capacity and rigidity of the reinforced concrete columns.
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Mhuder, Wathiq Jassim, and Samir M. Chassib. "Experimental Study of Strengthening of RC Columns with Steel Fiber Concrete." Materials Science Forum 1002 (July 2020): 551–64. http://dx.doi.org/10.4028/www.scientific.net/msf.1002.551.
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This study introduces an experimental program to investigate the performance of concrete wrapping jackets reinforced by steel fibers used for retrofitting of the square and circular RC columns under axial loads. Ten columns divided into two groups; the first group included seven square columns while the second group involved three circular columns. The experimental study included testing the columns with varied parameters such as cross-section shape, type and aspect ratio of steel fibres, jacket thickness, and using several techniques for retrofitting the column such as strengthening by plain and reinforced concrete jackets. The selected parameters affected the compressive behavior of confined columns high strength concrete jackets. The obtained results revealed that all strengthened columns with square cross-section appeared maximum strength greater than a circular one. Using several types of concrete jacketing promotes the load-capacity of the column with a clear improvement in the ductility. Increasing thickness appeared increasing in the load-carrying capacity in comparison with the reference column. Using the straight fibres showed better enhancement in the load capacity than the hooked ones. The main result was the failure mode was different from unstrengthen columns which showed more crushing in the concrete core with an increase in thickness.
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Preethi, G., and Prince G. Arulraj. "Optimal Design of Axially Loaded RC Columns." Bonfring International Journal of Industrial Engineering and Management Science 6, no. 3 (June 30, 2016): 78–81. http://dx.doi.org/10.9756/bijiems.7345.
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Raza, Saim, Muhammad K. I. Khan, Scott J. Menegon, Hing-Ho Tsang, and John L. Wilson. "Strengthening and Repair of Reinforced Concrete Columns by Jacketing: State-of-the-Art Review." Sustainability 11, no. 11 (June 9, 2019): 3208. http://dx.doi.org/10.3390/su11113208.
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Sustainability necessitates the protection of infrastructure from any kind of deterioration over the life cycle of the asset. Deterioration in the capacity of reinforced concrete (RC) infrastructure (e.g., bridges, buildings, etc.) may result from localised damage sustained during extreme loading scenarios, such as earthquakes, hurricanes or tsunamis. In addition, factors such as the corrosion of rebars or ageing may also deteriorate or degrade the capacity of an RC column, thereby necessitating immediate strengthening to either extend or ensure its design life is not limited. The aim of this paper is to provide a state-of-the-art review of various strengthening and repair methods for RC columns proposed by different researchers in the last two decades. The scope of this review paper is limited to jacketing techniques for strengthening and/or repairing both normal- and high-strength RC columns. The paper also identifies potential research gaps and outlines the future direction of research into the strengthening and repair of RC columns.
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Jiang, You Bao, Yu Lai Zhao, and Wei Jun Yang. "Seismic Reliability Analysis Based on Characteristics of Failure Function for RC Frame Columns with Large Eccentric Compression." Applied Mechanics and Materials 94-96 (September 2011): 1488–93. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.1488.
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Based on the analytical method, the failure function is obtained for reinforced concrete (RC) frame columns with large eccentric compression under vertical and horizontal loads together. A special characteristic is found that the whole correlative curve of vertical and horizontal loads may contain some rising parts under limit state, and the corresponding determinant condition is also proposed. With the approximate linearization of rising parts, the practical limit state function is also obtained. Then, the seismic reliability is calculated for RC frame columns with large eccentric compression under different combined ratios of gravity and horizontal earthquake loads according to the current Chinese design code. The results indicate that its reliability is lower than the reliability of RC frame beam when the strong column coefficient adopts low values. This provides some useful references for engineers to design RC columns with large eccentric compression reasonably.
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Wang, Gaoxiong, Yanhong Bao, Li Yang, and Yang Yu. "Analysis of Fire Resistance of Square-Cased Square Steel Tube Reinforced Concrete (ST-RC) Columns." Materials 14, no. 19 (September 24, 2021): 5541. http://dx.doi.org/10.3390/ma14195541.
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Based on the finite element (FE) analysis software Abaqus, an FE model of square-cased square steel tube reinforced concrete (ST-RC) columns under the hybridized action of high-temperature and load is established. The accuracy of the FE model is verified using experimental data from existing studies. This model is used to analyze the temperature change, internal force distribution, and failure characteristics of the square-cased square ST-RC columns under the action of fire, as well as the factors affecting the fire resistance limit of the column. The results of FE analysis show that under the action of fire, the maximum internal temperature of the square-cased square ST-RC columns occurs in the corner of the section. Moreover, the stress and strain reach their maximum values at the concrete corner outside the tube. During the heating process, an internal force redistribution occurs in the square-cased square ST-RC column. At the same time, the proportion of the axial force and the bending moment of the reinforced concrete outside the pipe decreases gradually, while the proportion of the internal force of the core concrete-filled steel tube (CFST) increases gradually. In essence, it is a process of load transfer from the high-temperature to the low-temperature zone. In addition, the section size, load ratio, slenderness ratio, cross-sectional core area ratio, steel content, and external concrete strength are the main parameters affecting the fire resistance limit of the square-cased square ST-RC columns. Among them, the cross-sectional core area ratio, section size, steel ratio, and external concrete strength are positively correlated with the fire resistance limit of the composite column. On the contrary, with the increase in the load ratio and the slenderness ratio, the fire resistance limit of the square-cased square ST-RC columns decreases. On this basis, a simplified formula to calculate the fire resistance limit of square-cased square ST-RC columns is proposed. The research results can be used as a theoretical reference for the fire protection design of this kind of structure in practical engineering.
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Liu, Zhenliang, and Suchao Li. "Development of an ANN-Based Lumped Plasticity Model of RC Columns Using Historical Pseudo-Static Cyclic Test Data." Applied Sciences 9, no. 20 (October 11, 2019): 4263. http://dx.doi.org/10.3390/app9204263.
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This study explores the possibility of using an ANN-based model for the rapid numerical simulation and seismic performance prediction of reinforced concrete (RC) columns. The artificial neural network (ANN) method is implemented to model the relationship between the input features of RC columns and the critical parameters of the commonly used lumped plasticity (LP) model: The strength and the yielding, capping and ultimate deformation capacity. Cyclic test data of 1163 column specimens obtained from the PEER and NEEShub database and other sources are collected and divided into the training set, test set and validation set for the ANN model. The effectiveness of the proposed ANN model is validated by comparing it with existing explicit formulas and experimental results. Results indicated that the developed model can effectively predict the strength and deformation capacities of RC columns. Furthermore, the response of two RC frame structures under static force and strong ground motion were simulated by the ANN-based, bi-linear and tri-linear LP model method. The good agreement between the proposed model and test results validated that the ANN-based method can provide sufficiently accurate model parameters for modeling the seismic response of RC columns using the LP model.
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Li, Xiaoya, Renbo Zhang, Liu Jin, and Xiuli Du. "Numerical analysis of axial compressive behavior of RC short columns subjected to non-uniform fire: A meso-scale study." E3S Web of Conferences 272 (2021): 02028. http://dx.doi.org/10.1051/e3sconf/202127202028.
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The bearing capacity and durability of reinforced concrete (RC) structures can be affected by fire. In this study, a three-dimensional (3D) meso-scale simulation model for RC short column subjected to axial compression after exposure to fire was established. The degradation effect of mechanical properties of steel bars and concrete materials after high temperature was taken into account. The bond-slip behavior between longitudinal steel bars and concrete was also considered in the model. Based on the present simulation method, the failure mode and failure mechanism of the RC short columns were investigated. Moreover, the effects of fire scenario and fire duration on the axial compression performance of RC short columns were further investigated. It is found that the meso-scale numerical model can effectively simulate the mechanical behavior of RC short columns under axial load. Moreover, with the increase of fired surfaces and fire duration, the peak bearing capacity, axial compression stiffness and ductility decrease. The mechanical properties of short columns decrease more quickly under non-uniform fire. By comparing the theoretical value with the numerical simulation value of Nut/Nu, it is found that the theoretical value is conservative.
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Li, Qiang, Xianyu Jin, Dan Wu, and Hailong Ye. "Acoustic Emission Analysis of Corroded Reinforced Concrete Columns under Compressive Loading." Sensors 20, no. 8 (April 23, 2020): 2412. http://dx.doi.org/10.3390/s20082412.
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In this work, the failure process of non-corroded and corroded reinforced concrete (RC) columns under eccentric compressive loading is studied using the acoustic emission (AE) technique. The results show that reinforcement corrosion considerably affects the mechanical failure process of RC columns. The corrosion of reinforcement in RC columns leads to highly active AE signals at the initial stage of loading, in comparison to the non-corroded counterparts. Also, a continuous AE hit pattern with a higher number of cumulative hits is observed for corroded RC columns. The spatial distribution and evolution of AE events indicate that the reinforcement corrosion noticeably accelerates the initiation and propagation of cracking in the RC columns during compressive loading. The AE characteristics of corroded RC columns are in agreement with the macroscopic failure behaviors observed during the damage and failure process. A damage evolution model of corroded RC columns based on the AE parameters is proposed.
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Lin, Hui, Yun Zou, Yi Xuan Chen, and Zhi Wei Wan. "Nonlinear Numerical Analysis of SRC-RC Transfer Columns." Applied Mechanics and Materials 193-194 (August 2012): 1129–33. http://dx.doi.org/10.4028/www.scientific.net/amm.193-194.1129.
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SRC-RC transfer columns are commonly designed as a transition floor for high-rising buildings to transfer from lower SRC columns to upper RC columns. The mechanical performances are studied in the paper using the finite element software of ABAQUS. Nonlinear numerical analyses are made for SRC-RC transfer columns firstly to obtain the relationship between force and displacement at top of the columns. By comparing the analytical results with experimental ones, it is found that the results from finite element analysis coincide well with experimental ones. So ABAQUS software could be used as a supplementary means to simulate SRC-RC transfer columns mechanical behavior. Then the factors such as steel ratio and axial compression ratio are contrastively analyzed. The results show that axial compression ratio has a greater influence on the bearing capacity and hysteretic performance of the structure, but the steel ratio has less influence. Finally, comparisons between SRC-RC and RC columns are also made to demonstrate the mechanical performance of SRC-RC columns further. Conclusions drawn in the study might be useful in practical engineering design.
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Sun, Yan Hua, Xio Yong Wu, and Guang Jing Xiong. "Seismic Behaviour of RC Columns Strengthened with Steel Bar/Wire Mesh Mortar." Key Engineering Materials 539 (January 2013): 108–14. http://dx.doi.org/10.4028/www.scientific.net/kem.539.108.
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In order to enhance the seismic behavior of reinforced concrete (RC) columns more efficiently, a thought to strengthen concrete columns by using steel bar/wire mesh mortar （FS）was proposed. An experimental study including five RC square columns strengthened with FS and steel bar mat mortar (S), respectively, under constant axial loading and lateral cyclic loading was carried out. Seismic bearing capacity, ductility, failure modes and hysteretic characteristics of all columns were tested, and the effect of reinforcement ratio and strengthening method to the tested columns was analyzed. The results showed that the energy dissipation capacity of FS strengthened columns was 73% higher than that of the S strengthened column, though the reinforcement ratio of the former was only 3.02% higher than that of the latter.