Compressive behavior of steel spiral confined engineered cementitious composites in circular columns

2020 ◽  
Vol 23 (14) ◽  
pp. 3075-3088
Author(s):  
Wei Hou ◽  
Guan Lin ◽  
Xiaomeng Li ◽  
Pandeng Zheng ◽  
Zixiong Guo
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Uniaxial Tensile ◽  
Cementitious Composites ◽  
Test Results ◽  
Cementitious Composite ◽  
Compression Tests ◽  
Compressive Behavior ◽  
Engineered Cementitious Composites ◽  
Engineered Cementitious Composite

Extensive research has been conducted on the uniaxial tensile and compressive behavior of engineered cementitious composites. Despite the high tensile ductility and high toughness of engineered cementitious composites, transverse steel reinforcement is still necessary for high-performance structural members made of engineered cementitious composites. However, very limited research has been concerned with the compressive behavior of steel-confined engineered cementitious composites. This article presents the results of axial compression tests on a series of circular engineered cementitious composite columns confined with steel spirals. The test variables included the engineered cementitious composite compressive strength, the spiral pitch, and the spiral yield stress. The test results show that steel-confined engineered cementitious composites in the test columns exhibited a very ductile behavior; the steel spiral confinement contributed effectively to the enhancement of both strength and ductility of engineered cementitious composites. The test results were then interpreted by comparing them with the predictions from some existing models. It was found that the existing models previously developed for confined concrete failed to predict the compressive strength of steel-confined engineered cementitious composites with sufficient accuracy. New fitting equations for the compressive properties of steel-confined engineered cementitious composites were then obtained on the basis of the test results of this study as well as those from an existing study.

scholarly journals Mechanical Properties and Carbonation Durability of Engineered Cementitious Composites Reinforced by Polypropylene and Hydrophilic Polyvinyl Alcohol Fibers

2018 ◽  
Author(s):  
Wei Zhang ◽  
Chenglong yin ◽  
Fuquan Ma ◽  
Zhiyi Huang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Polyvinyl Alcohol ◽  
Bending Strength ◽  
Impact Resistance ◽  
Steel Corrosion ◽  
Fiber Content ◽  
Uniaxial Tensile ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites

Herein, the mechanical properties and carbonation durability of engineered cementitious composites (ECC) were studied. For cost-efficient utilization of ECC materials, polypropylene (PP) and hydrophilic polyvinyl alcohol (PVA) fibers were employed to cast different types of specimens. The compressive strength, Poisson’s ratio, strength-deflection curves, cracking/post-cracking strength, impact index, and tensile strain-stress curves of the two types of ECC materials, with different fiber contents of 0 vol%, 1 vol%, 1.5 vol% and 2 vol%, were investigated by conducting compressive tests, four-point bending tests, drop weight tests, and uniaxial tensile tests. In addition, the matrix microstructure and failure morphology of the fiber in the ECC materials were studied by scanning electron microscopy (SEM) analysis. Furthermore, carbonation test and steel corrosion after carbonization were employed to study durability resistance. The results indicated that for both PP fiber- and hydrophilic PVA fiber-reinforced ECCs, the compressive strength first increases and then decreases as fiber content increases from 0 vol% to 2 vol% and reaches the maximum at 1 vol% fiber content. The bending strength, deformation capacity, and impact resistance show significant improvement with increasing fiber contents. The ECC material reinforced with 2 vol% PP fiber shows superior carbonized durability with maximum carbonation depth of only 0.8 mm.

Experimental Study of Uniaxial Tensile of High Performance Ductile Engineered Cementitious Composites

2011 ◽  
Vol 255-260 ◽  
pp. 2444-2448
Author(s):  
Jia Liang Kou ◽  
Ming Ke Deng ◽  
Xing Wen Liang
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Tensile Strain ◽  
Elasticity Modulus ◽  
Plain Concrete ◽  
Uniaxial Tensile ◽  
Cementitious Composites ◽  
Peak Strain ◽  
Stress Strain ◽  
Engineered Cementitious Composites

The tensile properties of high performance ductile engineered cementitious composites are tested through 60 specimens divided into 5 groups according to adding 5 various PVA fibres, the tensile strength, tensile elasticity modulus and the tensile pseudostrain-hardening stress-strain curves are obtained, the corresponding matrices are also tested for tension, the tensile strength relationships between different PVA fibres, and between tensile elasticity modulus and tensile strength are proposed according to the test results. In addition, multicracking can be see, and the ultimate tensile strain of partial high performance ductile engineered cementitious composites with filling different PVA fibres can reach to 3% which is 1000 times of the plain concrete. The influences of matrix and the different PVA fibres on ultimate tensile strain, peak stress and peak strain are analyzed by experimental data. At last, the tensile pseudostrain-hardening stress-strain curves are discussed, the experimental conclusions can provide a lot of experimental and theoretical bases for making the composites hold the high ductility consumption ability.

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.

Effect of freeze and thaw cycle on the mechanical properties of engineered cementitious composites with un-oiled fibers containing liquid and solid polymers

2022 ◽  
pp. 002199832110386
Author(s):  
Hadi Azadmanesh ◽  
Seyed Amir Hossein Hashemi ◽  
Seyed Hooman Ghasemi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bending Test ◽  
Styrene Butadiene Rubber ◽  
Uniaxial Tensile ◽  
Flexural Properties ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites ◽  
Freeze And Thaw ◽  
Thaw Cycle

Nowadays, the application of the engineered cementitious composites(ECC) is expected to highly develop. Due to the lack of access to oiled- polyvinyl alcohol (PVA) fibers in many parts of the world, the implementation of the ECC has contained many difficulties. In this study, to increase the mechanical properties of ECC with the use of un-oiled PVA fibers, the polymers of styrene butadiene rubber (SBR), and ethylene vinyl acetate (EVA) were taken into account to resolve the abovementioned issue. Herein, also in order to enhance the tensile and flexural properties of ECC, the cement was replaced by polymers. Accordingly, a total of 7 mix designs were planned to conduct the proposed tests. The compressive strength, uniaxial tensile strength, and three-point bending tests were performed on the ECC at their 28-day age with consideration of the freeze and thaw cycle. The results of this research illustrated that the use of polymers can enhance the tensile and flexural properties of the ECC with un-oiled PVA fibers. The tensile strain in this study increased by more than 3% after the application of the polymers. Furthermore, the compressive strength increased by more than 47 MPa, and the deflection at the mid-span reached more than 9 mm in the bending test. However, the results showed that the use of polymers was effective on the freeze and thaw cycle and almost preserved the mechanical properties of the ECC. SBR latex has higher compatibility with the ECC in comparison with EVA powder.

scholarly journals Effect of Modified Polyvinyl Alcohol Fibers on the Mechanical Behavior of Engineered Cementitious Composites

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 37 ◽  
Author(s):  
Mian Sun ◽  
Youzhi Chen ◽  
Jiaoqun Zhu ◽  
Tao Sun ◽  
Zhonghe Shui ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Polyvinyl Alcohol ◽  
Performance Improvement ◽  
Fracture Resistance ◽  
Cementitious Composites ◽  
Cementitious Composite ◽  
Engineered Cementitious Composites ◽  
Engineered Cementitious Composite ◽  
Pressure Resistance ◽  
Pva Fiber

：Polyvinyl alcohol (PVA) fiber was proposed to enhance the mechanical performance of engineered cementitious composite in this research. A mixture of engineered cementitious composite with better expected performance was made by adding 2% PVA fiber. Mechanics tests, including pressure resistance, fracture resistance, and ultimate tensile strength, were conducted. They reveal that the engineered cementitious composites not only exhibit good pressure resistance, but they also exhibit excellent fracture resistance and strain capability against tensile stress through mechanics tests, including pressure resistance, fracture resistance, and ultimate tensile resistance. To further improve the engineered composites’ ductility, attempts to modify the performance of the PVA fiber surface have been made by using a vinyl acetate (VAE) emulsion, a butadiene–styrene emulsion, and boric anhydride. Results indicated that the VAE emulsion achieved the best performance improvement. Its use in fiber pre-processing enables the formation of a layer of film with weak acidity, which restrains the hydration of adjacent gel materials, and reduces the strength of transitional areas of the fiber/composite interface, which restricts fiber slippage and pulls out as a result of its growth in age, and reduces hydration levels. Research illustrates that the performance-improvement processing that is studied not only improves the strain of the engineered cementitious composites, but can also reduce the attenuation of the strain against tensile stress.

Mechanical behavior of a novel precast beam-to-column connection with U-shaped bars and engineered cementitious composites

2018 ◽  
Vol 21 (13) ◽  
pp. 1963-1976 ◽  
Author(s):  
Bingqing Dong ◽  
Cong Lu ◽  
Jinlong Pan ◽  
Qifeng Shan ◽  
Wanyun Yin
Keyword(s):  
Energy Dissipation ◽  
Experimental Program ◽  
Cementitious Composites ◽  
Cementitious Composite ◽  
Engineered Cementitious Composites ◽  
Seismic Region ◽  
Engineered Cementitious Composite ◽  
Flexural Failure ◽  
Bonding Performance ◽  
Precast Column

This article investigates a novel precast connection, with U-shaped bars extending from precast column to connect with the longitudinal bars in precast beams. To improve the seismic behavior of the connection, engineered cementitious composites, one kind of highly ductile concrete, were introduced into the core area of the connection, which also act as the cast-in-place material in the beam top and end. Prior to the test, finite element modeling was conducted to determine the proper splice length between U-shaped bars and beam reinforcements and also to evaluate the bonding performance of the proposed connection. The experimental program was then carried out on a monolithic connection, a precast connection with normal concrete as well as a precast connection with engineered cementitious composite, after which the seismic behaviors of the connections including their failure mode, hysteresis characteristic, stiffness degradation, ductility, and energy dissipation were analyzed. All three types of connections underwent typical flexural failure where the joint area remained intact. The negative carrying capacity, ductility, and energy dissipation were slightly lower for the connection with concrete, while the connection with engineered cementitious composite exhibited satisfactory behavior comparable to monolithic specimens. The latter connection with engineered cementitious composite is therefore suggested to be applied in highly seismic region.

Elastoplastic time history analysis of reinforced engineered cementitious composite or engineered cementitious composite–concrete composite frame under earthquake action

2016 ◽  
Vol 20 (4) ◽  
pp. 491-503 ◽  
Author(s):  
Fang Yuan ◽  
Jinlong Pan ◽  
Christopher KY Leung
Keyword(s):  
Cyclic Loading ◽  
High Performance ◽  
Time History ◽  
Frame Structure ◽  
Dissipated Energy ◽  
Seismic Resistance ◽  
Cementitious Composite ◽  
Engineered Cementitious Composite ◽  
Composite Frame ◽  
Story Drift

Engineered cementitious composite is a class of high-performance cementitious composites with pseudo-strain hardening behavior and excellent crack control capacity. Substitution of concrete with engineered cementitious composite can greatly reduce the cracking and durability problems associated with low tensile strength and brittleness of concrete and can significantly increase structural seismic resistance. In this article, a pair of beam–column joints with various matrix types has been tested under reversed cyclic loading to study the effect of substitution of concrete with engineered cementitious composite in the joint zone on the seismic behaviors of composite members. After that, a simplified constitutive model of engineered cementitious composite under cyclic loading is proposed, and the structural performance of steel reinforced engineered cementitious composite members is simulated by fiber beam elements. The accuracy of the model is verified with test data. Finally, three frame structures with different matrixes subjected to earthquake actions were numerically modeled to verify the contribution of ductile engineered cementitious composite material to structural seismic resistance. The seismic responses or failure mechanisms, deformation patterns, and energy dissipation capacities for each frame structure are analyzed and compared. The simulation results indicate that the application of engineered cementitious composite can reduce the maximum story drift ratio, and the distributions of the dissipated energy are more uniform along the building height when engineered cementitious composite is strategically used in ground columns and beam–column joints of the frame structure. The seismic performance of the reinforced engineered cementitious composite-concrete composite frame is found to be even better than the frame with all concrete replaced by engineered cementitious composite.

Mechanical Properties of Modified Engineered Cementitious Composites (MECC) Incorporating Marble Dust

2021 ◽  
Vol 9 (8) ◽  
pp. 1140-1146
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bottom Surface ◽  
Cementitious Composites ◽  
Strength Development ◽  
Shape Effect ◽  
Main Concern ◽  
Engineered Cementitious Composites ◽  
Flexure Strength ◽  
Marble Dust

Engineered cementitious composites (ECC) are a type of high-performance fiber reinforced cementitious composite. ECC has different applications in the construction field due to its inherent characteristics of high tensile strain. The main concern regarding ECC is its high cost. The content of cement is high contributing to its cost. In this research work, the cement in ECC is replaced with marble dust and its mechanical properties such as compressive strength and flexure strength have been assessed. For this purpose, both cubes and cylinders were tested at different test ages for finding the compressive strength development with time and observe the shape effect of specimens on the compressive strength of ECC mixes. Beam members were tested for finding the flexure strength of ECC mixes. Deflection gauge was also installed at the mid span on the bottom surface of the beams to find the maximum mid span deflection before failure. The compression test results of both cylinders and cubes revealed that using of marble dust has negative effect on the compressive strength of ECC. The flexure strength result showed that marble dust can be used up to some extent replacing cement will increase the flexure strength. The result of mid span deflection suggests that by incorporating marble dust in ECC, its ductility increases.

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