Influence of Fiber Orientation on Bridging Performance of Polyvinyl Alcohol Fiber-Reinforced Cementitious Composite

2016 ◽  
Vol 113 (2) ◽  
Author(s):  
Toshiyuki Kanakubo ◽  
Masaru Miyaguchi ◽  
Kohei Asano
Keyword(s):  
Polyvinyl Alcohol ◽  
Fiber Orientation ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Polyvinyl Alcohol Fiber

scholarly journals Behavior Deterioration and Microstructure Change of Polyvinyl Alcohol Fiber-Reinforced Cementitious Composite (PVA-ECC) after Exposure to Elevated Temperatures

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5539
Author(s):  
Qing Wang ◽  
Boyu Yao ◽  
Runze Lu
Keyword(s):  
Polyvinyl Alcohol ◽  
Elevated Temperatures ◽  
Heating Temperature ◽  
Polymer Fibers ◽  
Cementitious Composites ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Explosive Spalling ◽  
Polyvinyl Alcohol Fiber ◽  
Dense Microstructure

In the case of fire, explosive spalling often occurs in cementitious composites due to dense microstructure and high pore-pressure. Polymer fibers were proved to be effective in mitigating such behavior. However, deterioration of these fiber-reinforced cementitious composites inevitably occurs, which is vital for the prediction of structural performance and prevention of catastrophic disaster. This paper concentrates on the behavior and mechanism of the deterioration of polyvinyl alcohol fiber-reinforced engineered cementitious composite (PVA-ECC) after exposure to elevated temperatures. Surface change, cracking, and spalling behavior of the cubic specimens were observed at room temperature, and after exposure to 200 °C, 400 °C, 600 °C, 800 °C, and 1200 °C. Losses in specimen weight and compressive strength were evaluated. Test results indicated that explosive spalling behavior was effectively prevented with 2.0 vol% polyvinyl alcohol fiber although the strength monotonically decreased with heating temperature. X-ray diffraction curves showed that the calcium hydroxide initially decomposed in the range of 400–600 °C, and finished beyond 600 °C, while calcium silicate hydrate began at around 400 °C and completely decomposed at approximately 800 °C. Micrographs implied a reduction in fiber diameter at 200 °C, exhibiting apparent needle-like channels beyond 400 °C. When the temperature was increased to 600 °C and above, the dents were gradually filled with newly produced substance due to the synergistic effect of thermal expansion, volume expansion of chemical reactions, and pore structure coarsening

Flexural Behavior of Polyvinyl Alcohol Fiber–Reinforced Ferrocement Cementitious Composite

2021 ◽  
Vol 33 (4) ◽  
pp. 04021040
Author(s):  
Wenping Du ◽  
Canqian Yang ◽  
Chong Wang ◽  
Yong Pan ◽  
Honglei Zhang ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Flexural Behavior ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Polyvinyl Alcohol Fiber

scholarly journals Modeling of Bridging Law for Bundled Aramid Fiber-Reinforced Cementitious Composite and its Adaptability in Crack Width Evaluation

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 179
Author(s):  
Daiki Sunaga ◽  
Takumi Koba ◽  
Toshiyuki Kanakubo
Keyword(s):  
Fiber Orientation ◽  
Crack Width ◽  
Volume Fraction ◽  
Characteristic Point ◽  
Crack Opening ◽  
Aramid Fiber ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Cross Sectional ◽  
Bridging Law

Tensile performance of fiber-reinforced cementitious composite (FRCC) after first cracking is characterized by fiber-bridging stress–crack width relationships called bridging law. The bridging law can be calculated by an integral calculus of forces carried by individual fibers, considering the fiber orientation. The objective of this study was to propose a simplified model of bridging law for bundled aramid fiber, considering fiber orientation for the practical use. By using the pullout characteristic of bundled aramid fiber obtained in the previous study, the bridging laws were calculated for various cases of fiber orientation. The calculated results were expressed by a bilinear model, and each characteristic point is expressed by the function of fiber-orientation intensity. After that, uniaxial tension tests of steel reinforced aramid-FRCC prism specimens were conducted to obtain the crack-opening behavior and confirm the adaptability of the modeled bridging laws in crack-width evaluation. The experimental parameters are cross-sectional dimensions of specimens and volume fraction of fiber. The test results are compared with the theoretical curves calculated by using the modeled bridging law and show good agreements in each parameter.

scholarly journals Crack Resistance and Mechanical Properties of Polyvinyl Alcohol Fiber-Reinforced Cement-Stabilized Macadam Base

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yi Zhao ◽  
Xuan Yang ◽  
Qingyu Zhang ◽  
Naixing Liang ◽  
Yangkai Xiang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polyvinyl Alcohol ◽  
Crack Resistance ◽  
Fiber Length ◽  
Cement Content ◽  
Strength Test ◽  
Fiber Reinforced ◽  
Polyvinyl Alcohol Fiber ◽  
Reinforced Cement ◽  
Shrinkage Property

A series of tests were carried out to evaluate crack resistance and mechanical properties of polyvinyl alcohol fiber-reinforced cement-stabilized macadam, which is widely used as pavement base or subbase composite material. Three series of cement-stabilized macadam mixtures with cement content of 3.2%, 3.6%, and 4.0% were prepared by incorporating four various contents (0, 0.6, 0.9, and 1.2 kg/m3) and lengths (12, 18, 24, and 30 mm) of polyvinyl alcohol fiber. The optimum polyvinyl alcohol fiber content, fiber length, and cement content were determined based on the mechanical properties of cement-stabilized macadam mixtures. Then, unconfined compressive strength test, compressive resilience modulus test, splitting strength test, flexural tensile strength test, drying shrinkage test, and temperature shrinkage test were carried out in this study. The results show that polyvinyl alcohol fiber-reinforced cement-stabilized prepared by optimum proportions (cement 3.6%, fiber content 0.9 kg/m3, and fiber length 24 mm) has good crack resistance. The incorporation of polyvinyl alcohol fiber can effectively improve compressive strength and splitting strength, while its effect on CRM of cement-stabilized macadam is not remarkable. The anti-dry-shrinkage property and anti-temperature-shrinkage property of the specimens are also drastically improved due to the reinforcement effect of polyvinyl alcohol fiber. Moreover, the crack resistance index is proposed to evaluate the crack resistance of materials. The crack resistance of PVA fiber-reinforced cement-stabilized macadam prepared by optimum proportions is improved by 44.4%. Consequently, the mechanical properties and crack resistance of cement-stabilized macadam are obviously improved by adding polyvinyl alcohol fiber.

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