scholarly journals Axial Strength of Eccentrically Loaded FRP-Confined Short Concrete Columns

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1261 ◽  
Author(s):  
Cheng Jiang ◽  
Yu-Fei Wu
Keyword(s):  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Experimental Program ◽  
Test Results ◽  
Axial Strength ◽  
Strength Enhancement ◽  
Reinforced Polymer ◽  
Frp Confinement ◽  
The Relationship ◽  
Increasing Load

This paper presents an experimental program that includes 78 fiber reinforced polymer (FRP)-confined square concrete columns subjected to eccentric loading. The degradation of the axial strength of FRP-confined short concrete columns due to the load eccentricity is investigated in this work. A larger load eccentricity leads to a greater decrease in the axial strength. From the test results, it is found that FRP confinement can cause less strength degradation compared with that of unconfined concrete specimens. For FRP-confined square concrete specimens, the strength enhancement due to FRP confinement increases with increasing load eccentricity. However, the increasing load eccentricity decreases the confinement efficiency for FRP-confined circular concrete specimens. The relationship between the strength of eccentrically loaded FRP-confined square columns and their corner radii is evaluated.

scholarly journals Compressive Behavior of FRP Grid-Reinforced UHPC Tubular Columns

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 125
Author(s):  
Junjie Zeng ◽  
Tianwei Long
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Ultra High Performance Concrete ◽  
Tubular Columns ◽  
Reinforced Polymer ◽  
Structural Applications ◽  
Frp Confinement

In this study, a novel form of tubular columns that is made of ultra-high-performance concrete (UHPC) internally reinforced with fiber-reinforced polymer (FRP) grid (herein referred to as FRP grid-UHPCtubular column) was developed. The axial compression test results of FRP grid-UHPC tubular columns with and without in-filled concrete are presented and discussed. Effects of the number of the FRP grid-reinforcing cages, the presence of in-filled concrete, and the presence of external FRP confinement were investigated. The test results confirmed that the FRP-UHPC tubular columns have a satisfactory compressive strength, and the strength and ductility of FRP-confined concrete-filled FRP grid-UHPC tube columns are enhanced due to the confinement from the FRP wrap. The proposed FRP grid-reinforced UHPC composite tubes are attractive in structural applications as pipelines or permanent formworks for columns, as well as external jackets (can be prefabricated in the form of two halves of tubes) for strengthening deteriorated reinforced concrete columns.

Response of Concrete Filled Carbon Sheet Tube Column under Axial and Lateral Loads

2015 ◽  
Vol 764-765 ◽  
pp. 1109-1113 ◽  
Author(s):  
Kyung Hoon Lee ◽  
Hee Cheul Kim ◽  
Jae Hong Kim ◽  
Young Hak Lee
Keyword(s):  
Experimental Tests ◽  
Fiber Reinforced Polymer ◽  
Analytical Models ◽  
Experimental Program ◽  
Test Results ◽  
Lateral Loads ◽  
Strain Characteristic ◽  
Second Stage ◽  
Reinforced Polymer ◽  
Carbon Sheet

Experimental tests have been conducted to investigate the performance of Concrete Filled Carbon Fiber Reinforced Polymer Sheet Tube (CFCST) columns. The main variables of this experimental program were the number and wrapping angles of CFRP sheets. In the first stage, stress versus strain characteristic of CFCST specimens was investigated by uni-axial tests. In the second stage, six full-scaled CFCST columns subjected to quasi-static lateral loading, as well as constant axial compression, were tested. The test results showed that the response of CFCST was seriously influenced by these two variables. This test results could be utilized for establishing the analytical models.

Refinement of an Ultimate Strain Model for Circular Concrete Columns Retrofitted with FRP Based on a Most Comprehensive Test Database

2013 ◽  
Vol 275-277 ◽  
pp. 1233-1238 ◽  
Author(s):  
Ying Wu Zhou ◽  
Feng Xing ◽  
Li Li Sui
Keyword(s):  
Axial Compression ◽  
Experimental Test ◽  
Concrete Columns ◽  
Ultimate Strain ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Reinforced Polymer ◽  
Comprehensive Test ◽  
Strain Model ◽  
Test Database

The retrofitting technique of externally wrapped by fiber reinforced polymer (FRP) can significantly enhance the deformability or ductility of deficient concrete columns. This paper develops a new advanced ultimate strain model for circular columns confined with FRP jacket based on a most updated and comprehensive test database where more than 800 axial compression test results of FRP confined circular concrete columns were collected newly. This work began with a careful review on some existing ultimate strain models after which an in-depth comparison between models predictions and experimental test results was conducted. The comparisons revealed that more or less defects of the existing models were detected and there existed large errors of their predictions as a much larger amount of columns than that used in the models derivations were evaluated. It is therefore necessary and of significance to refine a new advanced ultimate model in the paper.

scholarly journals Behaviour of carbon fibre–reinforced polymer-confined hollow circular concrete columns with inner polyvinyl chloride tube

2018 ◽  
Vol 21 (8) ◽  
pp. 1120-1133
Author(s):  
Hussam A Goaiz ◽  
Tao Yu ◽  
Muhammad NS Hadi
Keyword(s):  
Polyvinyl Chloride ◽  
Concrete Columns ◽  
Experimental Program ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Reinforced Polymer ◽  
Inner Surface ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Strength And Ductility

Existing studies have shown that the use of an inner tube can significantly enhance the effectiveness of confinement in fibre-reinforced polymer-confined hollow columns. The inner tube used in the existing studies, however, generally had a large stiffness and also served as longitudinal reinforcement. The use of a stiff inner tube is inefficient in resisting bending for hollow columns with a relatively small void and may be unnecessary for constraining the inner surface of concrete. Against this background, this article presents the first experimental study on fibre-reinforced polymer-confined hollow columns with an inner polyvinyl chloride tube. The experimental program included a total of 18 specimens which were tested under axial compression. The test variables included the section configuration (i.e. solid specimens, hollow specimens and hollow specimens with a polyvinyl chloride tube) and the thickness of fibre-reinforced polymer. The test results showed that due to the beneficial effect of the polyvinyl chloride tube which provided constraints/confinement from inside, fibre-reinforced polymer-confined hollow columns with an inner polyvinyl chloride tube generally possessed good strength and ductility compared to their counterparts without a polyvinyl chloride tube.

scholarly journals Assessment of Compression strength of Concrete Columns Confined with Basalt Fibre Reinforced Polymer

2019 ◽  
Vol 278 ◽  
pp. 03001
Author(s):  
CHIADIGHIKAOBI Paschal Chimeremeze
Keyword(s):  
Compression Strength ◽  
Concrete Columns ◽  
Test Results ◽  
Test Program ◽  
Basalt Fibre ◽  
Concrete Core ◽  
Strength Enhancement ◽  
Reinforced Polymer ◽  
Concrete Blocks ◽  
Fibre Reinforced Polymer

Columns are the main load bearing element of a structure. Therefore, columns have an important function in many structures and can be vulnerable to exceptional loads. As structures age, the columns often have a lack of transverse reinforcement, which is unable to provide sufficient confinement to the concrete core or to prevent buckling of the longitudinal reinforcement which causes premature strength degradation of the column. The primary objectives of this research are to investigate the behaviour of axially loaded concrete columns confined with an obscure material in civil engineer for strengthening, basalt fibre reinforced polymer jacket (BFRP). This paper presents a test program that was done on concrete blocks confined with basalt fibre reinforced polymer (BFRP) and examination of its compression strength. The test results show that the strength enhancement of the concrete blocks consists of more ductile behaviour.

scholarly journals Compressive behaviour of square fibre-reinforced polymer–concrete–steel hybrid multi-tube concrete columns

2017 ◽  
Vol 21 (8) ◽  
pp. 1162-1172 ◽  
Author(s):  
Chunwa Chan ◽  
Tao Yu ◽  
Shishun Zhang
Keyword(s):  
Axial Strain ◽  
Strain Curve ◽  
Concrete Columns ◽  
Experimental Program ◽  
Polymer Concrete ◽  
Test Results ◽  
Steel Tubes ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Polymer Tube

Fibre-reinforced polymer–concrete–steel hybrid multi-tube concrete columns are a new form of columns recently proposed at the University of Wollongong. An multi-tube concrete column consists of an external fibre-reinforced polymer tube and a number of circular internal steel tubes, with the space inside all the tubes filled with concrete. This article presents the first ever experimental study on square multi-tube concrete columns. The experimental program included a total of 14 stub column specimens tested under axial compression, with the test variables being the thickness of the external fibre-reinforced polymer tube, and the dimensions and configuration of the internal steel tubes. The test results demonstrated that the concrete in the square multi-tube concrete columns was very effectively confined by the multiple tubes, and that the buckling of the internal steel tubes was completely prevented, leading to full structural utilization of the materials and a very ductile response. The test results also showed that the behaviour of the concrete in the square multi-tube concrete columns was significantly superior to that in the corresponding square concrete-filled fibre-reinforced polymer tubes, in terms of the compressive strength, the ultimate axial strain and the stiffness of the second branch of the stress–strain curve. A simple analytical model proposed for the axial load-axial strain curve of square multi-tube concrete columns is also presented and is shown to provide reasonable and conservative predictions of the test results.

Experimental investigation on axial compressive behavior of fiber reinforced polymer-reinforced concrete columns confined with external fiber reinforced polymer jackets

2021 ◽  
pp. 136943322110262
Author(s):  
Chuanxiang Chen ◽  
Zhenyu Wang ◽  
Wei Zhou
Keyword(s):  
Reinforced Concrete ◽  
Concrete Columns ◽  
Concrete Cover ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Fiber Reinforced ◽  
Reinforced Concrete Columns ◽  
Reinforced Polymer ◽  
Frp Wrapping ◽  
Frp Bars

An innovative glass fiber reinforced polymer (GFRP) closed-type winding (GFRP-CW) tie was developed to eliminate the bond slip failure and make full use of the tensile strength of ties compared with conventional pultruded fiber reinforced polymer (FRP) rod ties. Although better confinement effect of GFRP-CW ties, however after spalling of concrete cover, the compressive longitudinal FRP bars in the plastic hinge regions of columns are most likely to crush or buckle. External FRP jackets can effectively restraint damage to concrete cover. Against this background, a novel FRP-reinforced concrete column confined with external FRP jackets and the internal GFRP-CW ties were proposed to prevent the FRP bars from premature buckling or crushing. In this article, twelve square new columns were constructed and tested to characterize the axial compressive behavior. The test parameters included FRP wrapping type (GFRP or carbon fiber reinforced polymer (CFRP)), FRP wrapping layers, and spacing of ties. Test results confirmed that FRP-reinforced concrete columns with external FRP jackets had significantly larger ductile behavior and exhibited higher load-carrying capacity than their counterparts FRP-reinforced concrete columns due to the contribution of longitudinal GFRP bars and the concrete cover. The test results also suggested reasonable spacing of ties and layers of GFRP jackets for an expected moderate confinement behavior.

A Developed Strength Model for FRP Confined Circular Concrete Columns Based on a Most Updated and Comprehensive Test Database

2013 ◽  
Vol 275-277 ◽  
pp. 1364-1369
Author(s):  
Ying Wu Zhou ◽  
Li Li Sui ◽  
Feng Xing ◽  
Ling Yi Wu
Keyword(s):  
Prediction Accuracy ◽  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Strength Model ◽  
Test Results ◽  
Reinforced Polymer ◽  
Comparison Results ◽  
Comprehensive Test ◽  
Strength Models ◽  
Test Database

This paper develops a new advanced strength model for circular columns retrofitted with fiber reinforced polymer (FRP) based on a newly collected test database which is so far the most updated and comprehensive one and has contained more than 800 axial compression test results of FRP confined circular concrete columns. This paper first reviews some existing design-oriented strength models and then provides an in-depth comparison between experimental test results and models predictions. The comparison results indicated that more or less deficiency exists when these models were extended to predict the confined strengths of a much larger amount of columns than that when they were derived, directly resulting in deteriorations of the prediction accuracy. These conclusions exactly reflect the necessity and significance of developing a new advanced confinement strength model in the paper.

Compression Tests on Large-Scale Concrete-Filled GFRP Tubes

2011 ◽  
Vol 71-78 ◽  
pp. 1113-1117
Author(s):  
Pan Xie
Keyword(s):  
Large Scale ◽  
Concrete Columns ◽  
Fiber Reinforced Polymer ◽  
Confined Concrete ◽  
Test Results ◽  
Compression Tests ◽  
Reinforced Polymer ◽  
Strain Behaviour ◽  
Calculation Results ◽  
Polymer Tubes

To enable reliable prediction of the stress-strain behaviour of GFRP-confined concrete, the mechanical properties of GFRP tube needs to be properly understood and modelled. This paper presents test results of an experimental investigation carried out on 400-mm-diameter and 800-mm-height concrete-filled fiber reinforced polymer tubes. A total of four GFRP-confined concrete columns were subjected to concentric compression to identify the properties of GFRP tube. The performance of GFRP tubes in the tests were compared with the calculation results based on the classical lamination theory. In addition, more in-depth interpretations of the test results and further tests need to be refined in future tests to better capture the properties of the GFRP tube.

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