Study on Evaluation Method for PVA Fiber Distribution in Engineered Cementitious Composite

Engineered cementitious composite (ECC) is a potential cement-based material with the abilities of large deformation and crack width control. However, ECC is difficult to popularize in many developing countries because the costs of silica sand and polyvinyl alcohol (PVA) fiber with a surface coating are too high for practical engineering. Therefore, we proposed an economical ECC with superfine river sand and polypropylene (PP) fiber (SSPP-ECC) to replace PVA fiber and silica sand. The SSPP-ECC proposed in this paper is a sustainable material using local material ingredients, which has considerable adaptability for large-scale engineering applications. The 16 groups of specimens were prepared through a factorial design method, curing for four-point bending tests. The bending strength, deflection, flexural modulus of elasticity, and crack width were measured and calculated during the test. The factor analysis of the test results shows that the contents of fiber and fly ash had significant effects on the ductility of SSPP-ECC with an extra combined effect at the same time, and a response surface model with high accuracy was fitted to predict the yield length of SSPP-ECC. The ductility of SSPP-ECC was positively related to its crack-control ability and it was shown that the crack width of SSPP-ECC increased significantly with a high content of superfine sand. This paper proposed a reasonable way to utilize superfine sand and provided the mix proportion of SSPP-ECC with characteristics of deformation hardening and multi-cracking, which may cater to the demands of many concrete components on ductility and crack resistance.

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Shear Load-Displacement Curves of PVA Fiber-Reinforced Engineered Cementitious Composite Expansion Joints in Steel Bridges

Applied Sciences ◽

10.3390/app9245275 ◽

2019 ◽

Vol 9 (24) ◽

pp. 5275

Author(s):

Liqiang Yin ◽

Shuguang Liu ◽

Changwang Yan ◽

Ju Zhang ◽

Xiaoxiao Wang

Keyword(s):

Composite Structure ◽

Composite Structures ◽

Shear Load ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Expansion Joints ◽

Failure Characteristics ◽

Engineered Cementitious Composite ◽

Load Displacement ◽

Pva Fiber

The concrete in the transition strips of expansion joints can become damaged prematurely during the service period. Polyvinyl alcohol (PVA) fiber-reinforced engineered cementitious composite (ECC) is a kind of high ductility concrete material, and its ultimate uniaxial tensile strain is more than 3%. It can be used to improve the damage status of expansion joints. Based on previous research results, ECCs were used in the pilot project of bridge expansion joints. Under this engineering background, the shear load-displacement curves of ECC expansion joints were studied through 27 groups of compression-shear tests of ECC/steel composite structures. The shear failure characteristics of ECC expansion joints were analyzed by the digital image correlation method. A shear load-displacement curve model of the composite structures was proposed based on the equivalent strain assumption and Weibull distribution theory. The results show that the failure mode of the composite structure specimens was ECC shear cracking. Stress and strain field nephograms were used to explain the failure characteristics of the composite structure specimens. The calculated curves of the shear load-displacement model of the composite structures were in good agreement with the experimental curves. The work is of great importance to the shear design of ECC expansion joints and their further engineering applications.

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Feasibility of Developing Engineered Cementitious Composite with High Volumes of Fly Ash Using Cost-Effective PVA Fiber

Journal of Testing and Evaluation ◽

10.1520/jte20170596 ◽

2018 ◽

Vol 48 (2) ◽

pp. 20170596

Author(s):

Jing Ji ◽

Shilong Zhang ◽

Liangqin Jiang ◽

Lijian Zhou ◽

Zhichao Xu ◽

...

Keyword(s):

Fly Ash ◽

Cost Effective ◽

Cementitious Composite ◽

Engineered Cementitious Composite ◽

Pva Fiber

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Mechanical Properties of Engineered Cementitious Composites Mixture

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.567.428 ◽

2014 ◽

Vol 567 ◽

pp. 428-433 ◽

Cited By ~ 1

Author(s):

Bashar S. Mohammed ◽

Muhammad Hafiz Baharun ◽

Muhd Fadhil Nuruddin ◽

Odu Paul Duku Erikol ◽

Nadhir Abdulwahab Murshed

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Flexural Strength ◽

The Self ◽

Cementitious Composite ◽

Fresh Properties ◽

Self Compacting Concrete ◽

Engineered Cementitious Composite ◽

Hardened Properties ◽

Pva Fiber

The aim of the research is to develop engineered cementitious composite mixtures satisfying the self-compacting concrete requirements and to evaluate the hardened properties of self-compacted ECC mixtures. To enhance the concrete performance, PVA is used. The PVA improved some characteristics and properties of the concrete. Ten mixes with different Polyvinyl Alcohol (PVA) fiber contents (0.0%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%) have been prepared. Three cubes (100mm x 100mm x 100mm), three beams (100mm x 100mm x 500mm) and three cylinders (150mm diameter and 300mm height) have been cast for each mix and tested at the age of 7 and 28 days for compressive strength and at age of 28 days for splitting and flexural strength. The V-funnel, L-box and slump test also have been conducted to access the fresh properties like workability and flowability of the concrete. The results indicated the increase in the strength of the concrete and the formulas for predicting the compressive, splitting and flexural strength from PVA (%) has been developed.

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

Materials ◽

10.3390/ma12010037 ◽

2018 ◽

Vol 12 (1) ◽

pp. 37 ◽

Cited By ~ 5

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.

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