scholarly journals Effect of Reinforced Concrete Jacketing on Axial Load Capacity of Reinforced Concrete Column

2020 ◽  
Vol 6 (7) ◽  
pp. 1266-1272
Author(s):  
Praveen Anand ◽  
Ajay Kumar Sinha

Whenever a member of a structure becomes structurally deficient, it becomes vulnerable to the existing load and for the additional loads that it may be subjected to in the coming future. Since columns are the most important structural element, the structural retrofit of columns, relative to other structural elements is of prime importance. This study intends to investigate the performance and behaviour of an RC column jacketed with Reinforced Concrete columns under axial loads. The objective of this paper is to find out the efficiency of RC jacket in enhancing the strength of an existing RC column. A mathematical design based upon Indian Standards codes has been designed to identify the behaviour of jacketed RC columns. This has been followed by a finite element based numerical simulation using the same material properties as used in the process of designing. The simulation has been done in ABAQUS software with appropriate contact modelling. The analytical model considers that there is no bond slippage between the existing and new concrete surface i.e. the bond between the existing and new concrete is assumed to be perfect. This perfect bond between the surfaces has been modelled by using appropriate constraints in ABAQUS software. The finite element models show fair agreement with the designed values in terms of ultimate capacity and failure mode. The load bearing capacity enhancement of the RC jacketed column has been found to increase substantially. The enhancement capacity results obtained from the finite element software differs about 16-25% from the design values.

2019 ◽  
Vol 5 (11) ◽  
pp. 2296-2308 ◽  
Author(s):  
Rania Salih Mohammed ◽  
Zhou Fangyuan

In this study, the behavior of reinforced concrete beams reinforced with FRP bars was investigated. A total of seventeen models were carried out based on the finite element software (ABAQUS). The concrete damage plasticity modeling was considered. Two types of fiber polymer bars, CFRP and GFRP as longitudinal reinforcement for concrete beam were used. The validation of numerical results was confirmed by experimental results, then the parametric study was conducted to evaluate the effect of change in different parameters, such as (diameter size, number of bars), type of FRP bars, longitudinal arrangement for FRP bars. All results were analyzed and discussed through, load-deflection diagram, according, to the difference parameter considered. The results showed that the use of FRP bars in rebar concrete beam improves the beam stiffness and enhance the cracking load. The load capacity enhanced in the range of (7.88-64.82%) when used CFRP bars. The load-carrying capacity of beams strengthened with CFRP is higher than that of strengthened with GFRP. Furthermore, the use of FRP bars in bottom and steel in top reinforcement is useful to overcome the large deflection, and improving the beam ductility. Finally, the results of finite element models were compared with the prediction equation, according to ACI440.1R-15.


2019 ◽  
Vol 972 ◽  
pp. 129-133
Author(s):  
Yasmeen Taleb Obaidat

Little research has been carried out in validating, fiber reinforced polymer (FRP) concrete strengthened column and the effective using partial wrapping. Also the effect of several parameter on strengthen column using the partial wrapping sheet of desired width and thickness around column have not been found out. To this end, a nonlinear 3D finite element model has been developed in current study for CFRP strengthened reinforced concrete column to simulate the behavior accompanied by the effect of partial wrapping with emphasis on load capacity and failure mode. The finite element simulation of CFRP strengthened RC columns is performed using commercial finite element program ABAQUS. Modelling was conducted on reinforced concrete columns with dimensions of 160 x 250 x 960 mm. The finite element model incorporates the nonlinear material behavior of concrete, bilinear stress-strain curve of steel and linear elastic behavior of CFRP material. The concrete was modeled using a plastic damage model. The performance of the FE model was studied by simulating experimental columns from the literature. The load, and strain of CFRP obtained from the FE study were compared with the corresponding experimental results. The FEM results agreed well with the experiments. In addition, to enhance our understanding of the behavior of strengthened reinforced concrete column capacity using partial wrapping the effect of changing the spacing between the CFRP sheets and number of layers were examined. The increase number of layers and decrease spacing give a higher ultimate load capacity, and delay the failure.


2012 ◽  
Vol 166-169 ◽  
pp. 1548-1553
Author(s):  
Jin Jun Guo ◽  
Yan Lu ◽  
Ping Xian Li

Based on eccentric compressive experiments of reinforced concrete column strengthened with jacketing method, the paper calculated and analyzed jacketing reinforcement of RC eccentric compressive column subjected to fire. The calculation procedure of residual load capacity of compressive member after fire was put forward according to temperature distribution at column section. To distinguish tensile or compressive failure of RC column, the formulas of relative balanced depth of compressive zone of jacketing section were deduced as well as the corresponding applied calculation method of norm section load capacity was presented under the second loaded stage. In addition, the reinforcement design and construction of one fire damaged building was conducted in terms of this paper’s method. The good running status of strengthened columns for many years validates the applicability of this method.


2014 ◽  
Vol 633-634 ◽  
pp. 947-951
Author(s):  
Peng Fei Zhang ◽  
Feng Ping Zhou ◽  
Zhong Qing Shen

The new damage assessment criteria of reinforced concrete column was analyzed and defined in the paper. RC column finite element analysis model was established, then damage patterns of the explosion impact on RC column are obtained by means of numerical simulation. The P-I curve of RC column is ascertained. Based on damage criteria and finite element analysis result, we put forward a simplified numerical method to ascertain RC column P-I curve. By contrast, the applicability and validity of simplified numerical method is satisfactory.


2013 ◽  
Vol 681 ◽  
pp. 99-104 ◽  
Author(s):  
Yu Feng Chen ◽  
Guang Xiang Yi

This paper does the data simulation analysis by using the large-scale finite element nonlinear ANSYS/LS-DYNA software. It chooses the MAT111(MAT-JOHNSON-HOLMQUIST -CONCRETE)concrete materials and the MAT3 (MAT-PLASTIC-KINEMATIC) reinforcement material model in ANSYS/LS-DYNA finite element software, builds the separating RC column finite element model, dynamically simulates the hurting process of RC column under the effect of explosive impact load, and mainly does research into the damage degree of RC column under different effects of explosive load of different peak pressures.


Author(s):  
Elsayed Ismail ◽  
Mohamed S. Issa ◽  
Khaled Elbadry

Abstract Background A series of nonlinear finite element (FE) analyses was performed to evaluate the different design approaches available in the literature for design of reinforced concrete deep beam with large opening. Three finite element models were developed and analyzed using the computer software ATENA. The three FE models of the deep beams were made for details based on three different design approaches: (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978), (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006), and Strut and Tie method (STM) as per ACI 318-14 (ACI318 Committee, Building Code Requirements for Structural Concrete (ACI318-14), 2014). Results from the FE analyses were compared with the three approaches to evaluate the effect of different reinforcement details on the structural behavior of transfer deep beam with large opening. Results The service load deflection is the same for the three models. The stiffnesses of the designs of (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and STM reduce at a load higher than the ultimate design load while the (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) reduces stiffness at a load close to the ultimate design load. The deep beam designed according to (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) model starts cracking at load higher than the beam designed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) method. The deep beam detailed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) and (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) failed due to extensive shear cracks. The specimen detailed according to STM restores its capacity after initial failure. The three models satisfy the deflection limit. Conclusion It is found that the three design approaches give sufficient ultimate load capacity. The amount of reinforcement given by both (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) is the same. The reinforcement used by the STM method is higher than the other two methods. Additional reinforcement is needed to limit the crack widths. (Mansur, M. A., Design of reinforced concrete beams with web openings, (2006)) method gives lesser steel reinforcement requirement and higher failure load compared to the other two methods.


2017 ◽  
Vol 10 (5) ◽  
pp. 1042-1050
Author(s):  
R. W. SOARES ◽  
S. S. LIMA ◽  
S. H. C. SANTOS

Abstract The structural design under seismic loading has been for many years based on force methods to consider the effects of energy dissipation and elastoplastic behavior. Currently, displacement-based methods are being developed to take into account elastoplastic behavior. These methods use moment-curvature relationships to determine the ductility capacity of a structural element, which is the deformation capacity of the element before its collapse. The greater the plastic displacement or rotation a structural member can achieve before it collapses, the more energy it is capable of dissipating. This plastic displacement or rotation capacity of a member is known as the member ductility, which for reinforced concrete members is directly related to efficient concrete confinement. This study investigates at which extents transverse reinforcement detailing influences reinforced concrete column ductility. For this, a bridge located in Ecuador is modeled and analyzed, and its ductility evaluated considering several cases of axial loading and concrete confinement levels. After the performed displacement-based analyses, it is verified whether the response modification factor defined by AASHTO is adequate in the analyzed case.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bedaso Ahmed ◽  
Kefiyalew Zerfu ◽  
Elmer C. Agon

Slender reinforced concrete column may fail in material failure or instability failure. Instability failure is a common problem which cannot be analyzed with first-order analysis. So, second-order analysis is required to analyze instability failure of slender RC column. The main objective of this study was to construct uniaxial interaction diagram for slender reinforced concrete column based on nonlinear finite element analysis (FEA) software. The key parameters which were studied in this study were eccentricity, slenderness ratio, steel ratio, and shape of the column. Concrete damage plasticity (CDP) was utilized in modeling the concrete. Material nonlinearity, geometric nonlinearity, effect of cracking, and tension stiffening effect were included in the modeling. The results reveal that, as slenderness ratio increases, the balanced moment also increases, but the corresponding axial load was decreased. However, increasing the amount of steel reinforcement to the column increases the stability of the column and reduces the effect of slenderness ratio. Also, the capacity of square slender RC column is larger than rectangular slender RC column with equivalent cross section. However, the result is close to each other as slenderness ratio increased. Finally, validation was conducted by taking a benchmark experiment, and it shows that FEA result agrees with the experimental by 85.581%.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Eden Shukri Kalib ◽  
Yohannes Werkina Shewalul

The responses of flat reinforced concrete (RC) floor slabs with openings subjected to horizontal in-plane cyclic loads in addition to vertical service loads were investigated using nonlinear finite element analysis (FEA). A finite element model (FEM) was designed to perform a parametric analysis. The effects of opening sizes (7%, 14%, 25%, and 30% of the total area of the slab), opening shapes (elliptical, circular, L-shaped, T-shaped, cross, and rectangular), and location on the hysteretic behavior of the floor slab were considered. The research indicated that openings in RC floor slabs reduce the energy absorption capacity and stiffness of the floor slab. The inclusion of 30% opening on the floor slab causes a 68.5%, 47.3%, and 45.6% drop in lateral load capacity, stiffness, and lateral displacement, respectively, compared to the floor slab with no openings. The flat RC floor slab with a circular opening shape has increased efficiency. The placement of the openings is more desirable by positioning the openings at the intersection of two-column strips.


The composite structural element under study is a carbon fiber wrapped, steel I section reinforced concrete column. The wrapped CFRP is under tension and reinforced concrete under radial compression. The aim of the research is to determine the behavior of the composite structural element under axial loads. The Stress-strain characteristics and load bearing capacity of control and CFRP wrapped tubular columns were determined experimentally. Further, Finite element analysis of steel, reinforced concrete and CFRP wrapped concrete columns sections, was conducted using ANSYS Workbench 15.0 software. The experimental and analytical results were compared.


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