Compressive behavior of small-diameter concrete-filled fiber-reinforced polymer tubes as internal reinforcements

2019 ◽  
Vol 23 (4) ◽  
pp. 713-732 ◽  
Author(s):  
Shu Fang ◽  
Li-Juan Li ◽  
Tao Jiang ◽  
Bing Fu
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Small Diameter ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Stress Strain ◽  
Reinforced Polymer ◽  
Polymer Tubes

Concrete infilled in a small-diameter fiber-reinforced polymer tube is strongly confined, thus having a high compressive strength and excellent deformability. Such a feature is exploited in the development of two types of high-performance hybrid members at Guangdong University of Technology, China, by incorporating small-diameter (30 to 60 mm) concrete-filled fiber-reinforced polymer tubes as internal reinforcements. Understanding the compressive behavior of small-diameter concrete-filled fiber-reinforced polymer tubes is essential to understanding the behavior of the proposed hybrid members and the development of their design approaches. This article therefore presents a systematic study on the axial compressive behavior of small-diameter concrete-filled fiber-reinforced polymer tubes with the test parameters being the thickness, diameter, and fiber type of fiber-reinforced polymer tubes and concrete strength. The test results show that the tested small-diameter concrete-filled fiber-reinforced polymer tubes have a compressive strength and an ultimate axial strain of up to 267 MPa and 10.3%, which are, respectively, about 6 and 34 times that of the corresponding unconfined specimens, demonstrating the great potential of small-diameter concrete-filled fiber-reinforced polymer tubes as internal reinforcements for use in high-performance hybrid members. The applicability of three widely accepted stress–strain models developed based on test results of fiber-reinforced polymer-confined concrete cylinders with a diameter of 150 mm or above is also examined. It is shown that the three models tend to predict a steeper second portion of stress–strain responses than the test results, revealing the need of a tailored stress–strain model for small-diameter concrete-filled fiber-reinforced polymer tubes.

The Effect of Confinement Method and Specimen End Condition on Behavior of FRP-Confined Concrete under Concentric Compression

2013 ◽  
Vol 351-352 ◽  
pp. 650-653 ◽  
Author(s):  
Thomas Vincent ◽  
Togay Ozbakkloglu
Keyword(s):  
Experimental Investigation ◽  
Cross Sections ◽  
Fiber Reinforced Polymer ◽  
Confined Concrete ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Stress Strain ◽  
Reinforced Polymer ◽  
Concrete Cylinders ◽  
Frp Tubes

This paper presents an experimental investigation on the influence of confinement method and specimen end condition on axial compressive behavior of fiber reinforced polymer (FRP)-confined concrete. A total of 12 aramid FRP (AFRP)-confined concrete specimens with circular cross-sections were tested. Half of these specimens were manufactured as concrete-filled FRP tubes (CFFTs) and the remaining half were FRP-wrapped concrete cylinders. The effect of specimen end condition was examined on both CFFTs and FRP-wrapped specimens. This parameter was selected to study the influence of loading the FRP jacket on the axial compressive behavior. In this paper the experimentally recorded stress-strain relationships are presented graphically and key experimental outcomes discussed. The results indicate that the performance of FRP-wrapped specimens is similar to that of CFFT specimens and the influence of specimen end condition is negligible.

Compressive behavior of circular and square concrete column externally confined by different types of basalt fiber–reinforced polymer

2020 ◽  
Vol 23 (8) ◽  
pp. 1534-1547 ◽  
Author(s):  
Jingting Huang ◽  
Tao Li ◽  
Dayong Zhu ◽  
Peng Gao ◽  
An Zhou
Keyword(s):  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Polymer Wrapping ◽  
Basalt Fiber Reinforced Polymer

This article studies the compressive behavior of concrete columns confined by different basalt fiber–reinforced polymers. A total of 30 columns were divided into 10 groups according to section shapes (circular and square), basalt fiber–reinforced polymer types (unidirectional basalt fiber–reinforced polymer, bidirectional basalt fiber–reinforced polymer, and hybrid basalt fiber–reinforced polymer/carbon fiber–reinforced polymers), and number of layers (0, 1, and 2). The test results showed that the compressive strengths of confined specimens increased by 20%–71% for circular columns and by 23%–41% for square columns. Similarly, the ultimate strains improved by 49%–296% for circular specimens and by 45%–145% for square specimens. The two-layer basalt fiber–reinforced polymer jacket had the best confinement effect, whereas the confining effect of bidirectional basalt fiber–reinforced polymer wrapping was relatively lower than that of unidirectional basalt fiber–reinforced polymer wrapping. Moreover, both the strength and ultimate strain of confined concrete improved with increasing number of basalt fiber–reinforced polymer layers. Finite element numerical models were also developed and verified by experimental results, and then the stress distributions of basalt fiber–reinforced polymer jackets and cross-sectional concrete were presented. Based on the test results and experimental data from several existing studies, modified strength and ultimate strain models were further developed for basalt fiber–reinforced polymer-confined circular and square columns.

Compressive Strength of Steel Fiber Reinforced Polymer Modified Recycled Aggregate Concrete

2021 ◽  
Vol 1166 ◽  
pp. 81-94
Author(s):  
Ganesh D. Awchat
Keyword(s):  
Compressive Strength ◽  
Steel Fiber ◽  
Recycled Aggregate Concrete ◽  
Fiber Reinforced Polymer ◽  
Recycled Aggregate ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Aggregate Concrete ◽  
Reinforced Polymer ◽  
Strain Behaviour

Demolish existing structures for better economic gains, functional and structural performance, and non-availability of land or disposal sites in nearby areas of all major cities worldwide turned as a significant reason for the crushing demolished concrete instead of using it as landfill. Research work aimed at arriving Recycled Concrete (RC) with the help of two materials, i.e. Steel Fibers (SF) and Styrene-Butadiene Rubber (SBR) latex, as additives to improve strength parameters of it. SF and SBR added in RC to examine & strengthen and termed as Steel Fiber Reinforced Polymer Modified Recycled Aggregate Concrete (SFRPMRAC). For this purpose, 198 cubes each of M20 (trial-1) and M25 (trial-2) cast separately to check compressive strength and its stress-strain behaviour for Natural Concrete (NC), RC & SFRPMRAC. The volume fractions of SF added 0.5%, 1% & 1.5% m3 of concrete and dosages of SBR latex varied from 2.5%, 5% and 7.5% by cement weight for preparation of cubes made of RC. From experimental results, SFRPMRAC with SF volume fraction of 1% m3 of concrete and 5% by cement weight provides an improvement in compressive strength by 8.62 % & 10.73 % for trial -1 and 11.51 % & 12.57 % for trial - 2 at 28 & 90 days when compared with NC. Compression stress-strain behaviour for SFRPMRAC with SF 1% m3 of concrete and 5% by weight of cement shows higher strain values at the peak stress. SFRPMRAC arrests the sudden drop of load due to co-matrix bond formation between SF and SBR in a linear direction compared to a similar NC & RC mix for both trials. It reflects significant improvement and approval of compressive strength for the desired purpose.

scholarly journals Compressive Behavior and Analytical Model of Ultra-Early Strength Concrete-Filled FRP Tube With Zero Curing Time

2022 ◽  
Vol 8 ◽  
Author(s):  
Yue Liu ◽  
Jia-Zhan Xie ◽  
Jing-Liang Yan
Keyword(s):  
Compressive Strength ◽  
Fiber Reinforced Polymer ◽  
Curing Time ◽  
Fiber Reinforced ◽  
Compression Tests ◽  
Compressive Behavior ◽  
Strength Concrete ◽  
Reinforced Polymer ◽  
Early Strength ◽  
Frp Tube

Fiber-reinforced polymer (FRP) has been widely used in civil engineering due to its light weight, high strength, convenient construction, and strong corrosion resistance. One of the important applications of FRP composites is the concrete-filled FRP tube (CFFT), which can greatly improve the compressive strength and ductility of concrete as well as facilitate construction. In this article, the compressive performances of a normal concrete-filled FRP tube (N-CFFT) column with 5-hour curing time and an ultra-early strength concrete-filled FRP tube (UES–CFFT) column with zero curing time were studied by considering the characteristics of rapid early strength improvement of ultra-early strength concrete and the confinement effect of the FRP tube. Monotonic axial compression tests were carried out on 3 empty FRP tubes (FTs) without an internal filler and 6 CFFT (3 N-CFFTs and 3 UES-CFFTs) specimens. All specimens were cylinders of 200 mm in diameter and 600 mm in height, confined by glass fiber–reinforced polymer (GFRP). Test results indicated that the compressive bearing capacity of the specimens increased significantly by adopting the ultra-early strength concrete as the core concrete of the CFFT, although the curing time was zero. It was also shown that the compressive behavior of the UES–CFFT specimens with zero curing time increased significantly than that of the N-CFFT specimens with 5-hour curing time because the former was able to achieve rapid strength enhancement in a very short time than the latter. The ultimate compressive strength of UES–CFFT specimens with zero curing time reached 78.3 MPa, which was 66.2 and 97.2% higher than that of N-CFFT with 5-hour curing time and FT specimens, respectively. In addition, a simple confinement model to predict the strength of UES–CFFT with zero curing time in ultimate condition was introduced. Compared with the existing models, the proposed model could predict the ultimate strength of UES–CFFT specimens with zero curing time with better accuracy.

Research on Static Load Tests of Damaged Bridge Strengthened with Pre-Stressed HFRP

2014 ◽  
Vol 1079-1080 ◽  
pp. 258-265
Author(s):  
Chen Ning Cai ◽  
Shan He ◽  
Li Na Liu ◽  
Shi Kun Ou
Keyword(s):  
Static Load ◽  
Flexural Rigidity ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Structural Members ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Load Tests

Thispaper presents an experimental study to strengthen an existing bridge usingpre-stressed carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer(GFRP) materials. The method using pre-stressed hybrid fiber reinforced polymer(HFRP) to strengthened structural members is an emerging pre-stressed strengtheningtechnology. In this study, experimental data selected from result of staticloading test conducted to hollow slabs with CFRP/GFRP has been compared with specimenswithout strengthening. Test results showed that the strengthening methoddeveloped in this study could effectively reduce the stress in hollow slab,improving the flexural rigidity and inhibiting the concrete from fracture.

scholarly journals Compressive Strength of Modified FRP Hybrid Bars

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1898
Author(s):  
Marek Urbański
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Basalt Fiber ◽  
Test Method ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Free Length ◽  
Compression Properties ◽  
Reinforced Polymer ◽  
Frp Bars

A new type of HFRP hybrid bars (hybrid fiber reinforced polymer) was introduced to increase the rigidity of FRP reinforcement, which was a basic drawback of the FRP bars used so far. Compared to the BFRP (basalt fiber reinforced polymer) bars, modification has been introduced in HFRP bars consisting of swapping basalt fibers with carbon fibers. One of the most important mechanical properties of FRP bars is compressive strength, which determines the scope of reinforcement in compressed reinforced concrete elements (e.g., column). The compression properties of FRP bars are currently ignored in the standards (ACI, CSA). The article presents compression properties for HFRP bars based on the developed compression test method. Thirty HFRP bars were tested for comparison with previously tested BFRP bars. All bars had a nominal diameter of 8 mm and their nonanchored (free) length varied from 50 to 220 mm. Test results showed that the ultimate compressive strength of nonbuckled HFRP bars as a result of axial compression is about 46% of the ultimate strength. In addition, the modulus of elasticity under compression does not change significantly compared to the modulus of elasticity under tension. A linear correlation of buckling load strength was proposed depending on the free length of HFRP bars.

Compressive Behavior of Circular Concrete Columns Confined by Basalt Fiber Reinforced Polymer (BFRP)

2018 ◽  
Vol 765 ◽  
pp. 355-360 ◽  
Author(s):  
Sakol Suon ◽  
Shahzad Saleem ◽  
Amorn Pimanmas
Keyword(s):  
Basalt Fiber ◽  
Concrete Columns ◽  
Primary Objective ◽  
Fiber Reinforced Polymer ◽  
Small Scale ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Reinforced Polymer ◽  
Ductile Behavior ◽  
Basalt Fiber Reinforced Polymer

This paper presents an experimental study on the compressive behavior of circular concrete columns confined by a new class of composite materials originated from basalt rock, Basalt Fiber Reinforced Polymer (BFRP). The primary objective of this study is to observe the compressive behavior of BFRP-confined cylindrical concrete column specimens under the effect of different number of layers of basalt fiber as a study parameter (3, 6, and 9 layers). For this purpose, 8 small scale circular concrete specimens with no internal steel reinforcement were tested under monotonic axial compression to failure. The results of BFRP-confined concrete specimens of this study showed a bilinear stress-strain response with two ascending branches. Consequently, the performance of confined columns was improved as the number of BFRP layer was increased, in which all the specimens exhibited ductile behavior before failure with significant strength enhancement. The experimental results indicate the well-performing of basalt fiber in improving the concrete compression behavior with an increase in number of FRP layers.

Sign in / Sign up

Export Citation Format

Share Document