Modeling of Bridging Law for PVA Fiber-Reinforced Cementitious Composite Considering Fiber Orientation

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.

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Pullout Behavior of Bundled Aramid Fiber in Fiber-Reinforced Cementitious Composite

Materials ◽

10.3390/ma13071746 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1746 ◽

Cited By ~ 2

Author(s):

Toshiyuki Kanakubo ◽

Saki Echizen ◽

Jin Wang ◽

Yu Mu

Keyword(s):

Crack Width ◽

Maximum Load ◽

Aramid Fiber ◽

Matrix Cracking ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Integral Calculus ◽

The Matrix ◽

Pullout Load ◽

Bridging Law

The tensile performance of fiber-reinforced cementitious composite (FRCC) after first matrix cracking is characterized by a tensile stress–crack width relationship called the bridging law. The bridging law can be obtained by an integral calculus of forces carried by individual bridging fibers considering the effect of the fiber inclination angle. The main objective of this study is to investigate experimentally and evaluate the pullout behavior of a single aramid fiber, which is made with a bundling of original yarns of aramid fiber. The bundled aramid fiber has a nonsmooth surface, and it is expected to have good bond performance with the matrix. The test variables in the pullout test are the thickness of the matrix and the inclined angle of the fiber. From the test results, the pullout load–slip curves showed that the load increases lineally until maximum load, after which it decreases gradually. The maximum pullout load and slip at the maximum load increase as the embedded length of the fiber becomes larger. The pullout load–crack width relationship is modeled by a bilinear model, and the bridging law is calculated. The calculated result shows good agreement with the experimental curves obtained by the uniaxial tension test of aramid–FRCC.

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

ACI Materials Journal ◽

10.14359/51688633 ◽

2016 ◽

Vol 113 (2) ◽

Cited By ~ 2

Author(s):

Toshiyuki Kanakubo ◽

Masaru Miyaguchi ◽

Kohei Asano

Keyword(s):

Polyvinyl Alcohol ◽

Fiber Orientation ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Polyvinyl Alcohol Fiber

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Effect of PVA fiber on durability of cementitious composite containing nano-SiO2

Nanotechnology Reviews ◽

10.1515/ntrev-2019-0011 ◽

2019 ◽

Vol 8 (1) ◽

pp. 116-127 ◽

Cited By ~ 22

Author(s):

Peng Zhang ◽

Qing-fu Li ◽

Juan Wang ◽

Yan Shi ◽

Yi-feng Ling

Keyword(s):

Volume Fraction ◽

Fiber Content ◽

Nano Particles ◽

Cementitious Composites ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Cracking Resistance ◽

Carbonation Resistance ◽

Pva Fiber

Abstract In the current investigation, the influence of polyvinyl alcohol (PVA) fibers on flowability and durability of cementitious composite containing fly ash and nano-SiO2 was evaluated. PVA fibers were added into the composite at a volume fraction of 0.3%, 0.6%, 0.9%, and 1.2%. The flowability of the fresh cementitious composite was assessed using slump flow. The durability of cementitious composite includes carbonation resistance, permeability resistance, cracking resistance as well as freezing-thawing resistance, which were evaluated by the depth of carbonation, the water permeability height, cracking resistance ratio of the specimens, and relative dynamic elastic modulus of samples after freeze-thaw cycles, respectively. The results indicated that addition of PVA fibers had a little disadvantageous influence on flowability of cementitious composite, and the flowability of the fresh mixtures decreased with increases in PVA fiber content. Incorporation of PVA fibers significantly improved the durability of cementitious composites regardless of addition of nano-particles. When the fiber content was less than 1.2%, the durability indices of permeability resistance and cracking resistance increased with fiber content. However, the durability indices of carbonation resistance and freezing-thawing resistance began to decrease as the fiber dosage increased from 0.9% to 1.2%. The fiber reinforced cementitious composite exhibited better durability due to addition of nano-SiO2 particles. Nano-SiO2 particle improves microscopic structure of fiber reinforced cementitious composites, and the nano-particles are beneficial for PVA fibers to play the role of reinforcement in cementitious composites.

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Effect of Nano-Particle on Durability of Polyvinyl Alcohol Fiber Reinforced Cementitious Composite

Science of Advanced Materials ◽

10.1166/sam.2020.3680 ◽

2020 ◽

Vol 12 (2) ◽

pp. 249-262 ◽

Cited By ~ 7

Author(s):

Peng Zhang ◽

Qingfu Li ◽

Juan Wang ◽

Yan Shi ◽

Yuanxun Zheng ◽

...

Keyword(s):

Polyvinyl Alcohol ◽

Nano Particles ◽

Nano Particle ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Cracking Resistance ◽

Flow Measurements ◽

Carbonation Resistance ◽

Pva Fiber

In this study, the influence of nano-particle on flowability and durability of polyvinyl alcohol (PVA) fibers reinforced cementitious composite containing fly ash was evaluated. In the cementitious composite, Portland cement was replaced with 1.0%, 1.5%, 2.0% and 2.5% (by weight) of nano-particles. Two kinds of nano-particle of SiO2 and CaCO3 nano-particles were adopted in this study. PVA fibers were incorporated to the composite at a dosage of 0.9% (by volume). The flowability of the fresh cementitious composite was assessed using slump flow measurements. The durability of hardened cementitious composite includes carbonation resistance, permeability resistance, cracking resistance as well as freezing-thawing resistance, which were evaluated by the depth of carbonation, the water permeability height, cracking resistance ratio of the specimens, and relative dynamic elastic modulus of samples after freeze-thaw cycles, respectively. Our results showed incorporation of nano-particles had a little disadvantageous effect on flowability of PVA fiber reinforced cementitious composite, and the flowability of the fresh mixtures decreased with increases in the nano-particles content. The decrease in flowability of cementitious composite resulted by nano-SiO2 particles is more remarkable than nano-CaCO3 particles. The addition of both nano-SiO2 and nano-CaCO3 particles significantly improved the durability of PVA fiber reinforced cementitious composite. However, the improvement of nano-SiO2 on durability is much better than that of nano-CaCO3. When the amount of SiO2 nano-particle was less than 2.5%, the durability of cementitious composites increased with nano-SiO2 content. The microstructure of PVA fiber reinforced cementitious composite becomes much denser due to filler effect of nano-particle and generation of particles of hydrated products C–S–H gels. Both of SiO2 and CaCO3 nano-particle improved the microstructure of PVA fiber reinforced cementitious composite, and nano-SiO2 particles might be more beneficial for PVA fibers to play the role of reinforcement than nano-CaCO3 particles in the composites.

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Compressive Strength Prediction of PVA Fiber-Reinforced Cementitious Composites Containing Nano-SiO2 Using BP Neural Network

Materials ◽

10.3390/ma13030521 ◽

2020 ◽

Vol 13 (3) ◽

pp. 521 ◽

Cited By ~ 1

Author(s):

Ting-Yu Liu ◽

Peng Zhang ◽

Juan Wang ◽

Yi-Feng Ling

Keyword(s):

Neural Network ◽

Genetic Algorithm ◽

Compressive Strength ◽

Bp Neural Network ◽

Cementitious Composites ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Nano Sio2 ◽

Pva Fiber ◽

Fiber Reinforced Cementitious Composites

In this study, a method to optimize the mixing proportion of polyvinyl alcohol (PVA) fiber-reinforced cementitious composites and improve its compressive strength based on the Levenberg-Marquardt backpropagation (BP) neural network algorithm and genetic algorithm is proposed by adopting a three-layer neural network (TLNN) as a model and the genetic algorithm as an optimization tool. A TLNN was established to implement the complicated nonlinear relationship between the input (factors affecting the compressive strength of cementitious composite) and output (compressive strength). An orthogonal experiment was conducted to optimize the parameters of the BP neural network. Subsequently, the optimal BP neural network model was obtained. The genetic algorithm was used to obtain the optimum mix proportion of the cementitious composite. The optimization results were predicted by the trained neural network and verified. Mathematical calculations indicated that the BP neural network can precisely and practically demonstrate the nonlinear relationship between the cementitious composite and its mixture proportion and predict the compressive strength. The optimal mixing proportion of the PVA fiber-reinforced cementitious composites containing nano-SiO2 was obtained. The results indicate that the method used in this study can effectively predict and optimize the compressive strength of PVA fiber-reinforced cementitious composites containing nano-SiO2.

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