Theoretical Analysis of Axial Compression of Reinforced Concrete Short-Columns Strengthened with CFRP Sheets

2013 ◽  
Vol 791-793 ◽  
pp. 323-325
Author(s):  
Xiao Chu Wang ◽  
Hong Bin Nie ◽  
Jian Peng Zhang
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Theoretical Analysis ◽  
Carrying Capacity ◽  
Concrete Column ◽  
Strength Model ◽  
Lateral Stress ◽  
Concrete Compressive Strength ◽  
Cfrp Sheets ◽  
Short Columns

CFRP cloth strengthening concrete column is divided into constrained and unconstrained District area by the reasonable arch axis theory, then we obtain the effective confinement factor of reinforced columns, base on lateral stress formula of scholar XIAO Y and concrete compressive strength model of Karbhari, V. M, derive from the increasing coefficient of carrying capacity, according to the effective confinement factor and the increasing coefficient of carrying capacity, finally we obtain the bearing capacity formula of the modified compression column strengthened with CFRP sheets.

Analysis and Prospect of Size Effect on Normal Section Bearing Capacity of Reinforced Concrete Column

2013 ◽  
Vol 351-352 ◽  
pp. 422-426
Author(s):  
Yong Ping Xie ◽  
Lei Jia ◽  
Gang Sun
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Theoretical Analysis ◽  
Size Effect ◽  
Bearing Capacity ◽  
Concrete Column ◽  
Concrete Compressive Strength ◽  
Reinforced Concrete Column ◽  
Normal Section

With the development of modern constructional technique, more attention on the size effect is paid by academics and engineers. The normal section bearing capacity of Reinforced Concrete Column is analyzed by eccentrically compressed theory firstly. The size effect on normal section bearing capacity of reinforced concrete column is obtained by theoretical analysis and experimental summary. The size effect formula of concrete compressive strength is proposed. Finally, a research thinking of size effect on bearing capacity is suggested.

Guidelines for flexural design of FRP reinforced concrete beams

2020 ◽  
pp. 002199832097373
Author(s):  
Fares Jnaid
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Large Diameter ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Concrete Compressive Strength ◽  
Load Carrying ◽  
Multiple Variables

This paper investigates the effects of different parameters on the live load carrying capacity of concrete beams reinforced with FRP bars. The author performed a parametric study utilizing an innovative numerical approach to inspect the effects of multiple variables such as reinforcement ratio, concrete compressive strength, span to depth ratio, FRP type, and bar diameter on load carrying capacity of FRP reinforced concrete beams. This study concluded that unless the span to height ratio is smaller than 8, tension-controlled sections are impractical as they do not meet code requirements for serviceability. In addition, it is recommended to use higher reinforcement ratios when using larger span to depth ratios and/or when using CFRP reinforcing bars. Moreover, larger number of bars with small diameter is more practical than fewer large diameter bars. Furthermore, this research suggests that increasing the concrete compressive strength is associated with a significant increase in the ultimate flexural capacity of FRP reinforced beams.

scholarly journals Finite element analysis of mechanical behavior of concrete-filled square steel tube short columns with inner I-shaped CFRP profiles subjected to bi-axial eccentric load

2018 ◽  
Author(s):  
Guochang Li ◽  
Zhichang Zhan ◽  
Zhijian Yang ◽  
Yu Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Steel Tube ◽  
Concrete Compressive Strength ◽  
Eccentric Load ◽  
Element Analysis ◽  
Composite Columns ◽  
Short Columns ◽  
Square Steel Tube

The concrete-filed square steel tube with inner I-shaped CFRP profiles short columns under bi-axial eccentric load were investigated by the finite element analysis software ABAQUS. The working mechanism of the composite columns which is under bi-axial eccentric load are investigated by using the stress distribution diagram of steel tube concrete and the I-shaped CFRP profiles. In this paper, the main parameters; eccentric ratio, steel ratio, steel yield strength, concrete compressive strength and CFRP distribution rate of the specimens were investigated to know the mechanical behavior of them. The interaction between the steel tube and the concrete interface at different characteristic points of the composite columns were analyzed. The results showed that the ultimate bearing capacity of the concrete-filed square steel tube with inner I-shaped CFRP profiles short columns under bi-axial eccentric load decrease with the increase of eccentric ratio, the ultimate bearing capacity of the composite columns increase with the increase of steel ratio, steel yield strength, concrete compressive strength and CFRP distribution rate. The contact pressure between the steel tube and the concrete decreased from the corner zone to the flat zone, and the contact pressure decreased from the mid-height cross section to other sections.

The Research of Concrete Short Columns Strengthed with Angle Steel

2014 ◽  
Vol 941-944 ◽  
pp. 877-882
Author(s):  
Fang Zhang ◽  
Sheng Bai ◽  
Jin Feng Hao
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Concrete Column ◽  
Reinforcement Effect ◽  
Reinforced Concrete Column ◽  
Short Columns ◽  
Angle Steel

Through the analysis of the possibilities of failure modes of RC short columns and advantages of outsourcing steel stick hair,put forward the method of reinforced concrete column strengthened with angle steel,and analyse its reinforcement effect through the experiment.

scholarly journals Construction of N-M Interaction Diagram for Reinforced Concrete Columns Strengthened with Steel Jackets Using Plastic Stress Distribution Method

2017 ◽  
Vol 3 (10) ◽  
pp. 929
Author(s):  
Mohannad Husain Al-Sherrawi ◽  
Hamza M. Salman
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Stress Distribution ◽  
Concrete Columns ◽  
Concrete Compressive Strength ◽  
Distribution Method ◽  
Reinforced Concrete Columns ◽  
Interaction Diagram ◽  
Steel Angle ◽  
Plastic Stress

No attempts have been made in developing the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method. Therefore, this paper presents an analytical model to construct the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method after assuming the behavior of strengthened column to be like composite column and including the effects of confinement on concrete compressive strength. The proposed model was compared with experimental results. The comparisons showed that the model is conservative and it reveals the ultimate strength of the strengthened column. A parametric study has been also carried out to investigate the influence of various parameters on the N-M interaction diagram of the strengthened column. These parameters were: dimensions of steel angle, yield stress of the steel angles, concrete compressive strength and the size of the reinforcement bars used in RC columns. The results made clear the effects of these parameters on the N-M interaction diagram, and encouraged the use of the model in preliminary strengthening studies.

scholarly journals Cyclic performance of exterior R.C beam-column strengthened with different thicknesses of CFRP sheets

2022 ◽  
Vol 961 (1) ◽  
pp. 012069
Author(s):  
Mustafa Kareem Hamzah ◽  
Raizal Saifulnaz M. Rashid ◽  
Farzad Hejazi
Keyword(s):  
Compressive Strength ◽  
Plastic Hinge ◽  
Cost Effective ◽  
Cyclic Performance ◽  
Concrete Compressive Strength ◽  
Cfrp Sheets ◽  
Panel Zone ◽  
External Strengthening ◽  
Damage States ◽  
Hinge Zone

Abstract The recent ground motion results indicated that the RC buildings are required to be retrofitted by different strengthening techniques. Nowadays, the external strengthening gain interest since its easy, cost effective and not required redesign of buildings. The CFRP sheets are suitable solution and utilized by a number of researchers. However, the numerical cyclic performance of connection strengthened with different thicknesses of CFRP need to be well investigated. This study assessed the performance of RC exterior beam column connection strengthened with CFRP sheets First, two grades of concrete are utilized to be control specimens, normal concrete compressive strength (C20) and high concrete compressive strength (C50) then, the specimens are retrofitted with different thicknesses (1.2, 2.4, 3.6mm) of CFRP sheets. The stresses and damage states showed the importance of connection retrofitting. The CFRP shift the plastic hinge zone away from the panel zone. Furthermore, the results demonstrated that by increase of CFRP thickness the connection resistance will be improved. The comparison between the hysteresis curves demonstrated that the yield and ultimate loading were enhanced for strengthened connection for both concrete grades and the incremental in thicknesses also increase them. The outputs also exhibited that the stiffness and ductility has increased for retrofitted specimens indicating that the CFRP comprehensively overcome the applied cyclic loading and the beam column connection is able to resist such type of loading.

scholarly journals Research on compressive strength of hybrid fiber reinforced concrete based on orthogonal design

2021 ◽  
Vol 261 ◽  
pp. 02019
Author(s):  
Tu-Sheng He ◽  
Meng-Qian Xie ◽  
Yang Liu ◽  
San-Yin Zhao ◽  
Zai-Bo Li
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Prediction Model ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Concrete Compressive Strength ◽  
Hybrid Fiber

The influence of steel fiber and polypropylene fiber mixed on compressive strength of high performance concrete (HPC) was studied. The steel fiber content (0.5%, 1.0%, 1.5%, 2.0%) (volume fraction, the same below), polypropylene fiber content (0.05%, 0.1%, 0.15%, 0.2%) and length (5mm, 6.5mm, 12mm, 18mm) were studied by L16 (45) orthogonal test for 28d ages, the range analysis and variance analysis of the test results are carried out, and the prediction model of compressive strength of hybrid fiber reinforced concrete was established. The results show that: The significant influence factor of concrete compressive strength is the volume fraction of polypropylene fiber, while the length of polypropylene fiber and the volume fraction of steel fiber are not significant; the concrete compressive strength with polypropylene fiber shows negative hybrid effect; The prediction model of compressive strength of hybrid fiber reinforced concrete has high accuracy, and the average relative errors is 2.96%.

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