scholarly journals Durability of Steel Fiber-Reinforced Concrete Containing SiO2 Nano-Particles

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2184 ◽  
Author(s):  
Peng Zhang ◽  
Qingfu Li ◽  
Yuanzhao Chen ◽  
Yan Shi ◽  
Yi-Feng Ling
Keyword(s):  
Steel Fiber ◽  
Fiber Content ◽  
Steel Fibers ◽  
Nano Particles ◽  
Cracking Resistance ◽  
Water Permeation ◽  
Nano Sio2 ◽  
Carbonation Resistance ◽  
Sio2 Particles ◽  
Durability Of Concrete

An experimental study was conducted to investigate the effect ofnano-SiO2 and steel fiber content on the durability of concrete. Five different dosages of nano-SiO2 particles and five volume dosages of steel fiber were used. The durability of concretes includes permeability resistance, cracking resistance, carbonation resistance, and freezing-thawing resistance, and these were evaluated by the water permeation depth, number of cracks, total cracking area per unit area of the specimens, carbonation depth of the specimens, and the relative dynamic elastic modulus of the specimens after freezing-thawing cycles, respectively. The results indicate that the addition of nano-SiO2 particles significantly improves the durability of concrete when the content of nano-SiO2 is limited within a certain range. With the increase of nano-SiO2 content, the durability of concrete first increases and then decreases. An excessive number of nano-SiO2 particles could have an adverse effect on the durability of the concrete. The addition of the correct amount of steel fibers improves the carbonation resistance of concrete containing nano-particles, but excessive steel fiber reduces the carbonation resistance. Moreover, the addition of steel fibers reduces the permeability resistance of concrete containing nano-particles. The incorporation of steel fiber enhanced the freezing-thawing resistance and cracking resistance of concrete containing nano-particles. With increasing steel fiber content, the freezing-thawing resistance of the concrete containing nano-particles increases, and the cracking resistance of the concrete decreases gradually.

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

2019 ◽  
Vol 8 (1) ◽  
pp. 116-127 ◽  
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.

Combined effect of nano-SiO2 particles and steel fibers on flexural properties of concrete composite containing fly ash

2014 ◽  
Vol 21 (4) ◽  
pp. 597-605 ◽  
Author(s):  
Peng Zhang ◽  
Ya-nan Zhao ◽  
Chen-hui Liu ◽  
Peng Wang ◽  
Tian-hang Zhang
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Steel Fiber ◽  
Flexural Modulus ◽  
Fiber Content ◽  
Steel Fibers ◽  
Combined Effect ◽  
Nano Particles ◽  
Flexural Properties

AbstractThis paper presents an experimental study to evaluate the combined effect of nano-SiO2 particles and steel fibers on flexural properties of concrete composites containing fly ash. In this study, five different nano-SiO2 contents (1%, 3%, 5%, 7%, and 9%) and five different steel fiber contents (0.5%, 1%, 1.5%, 2%, and 2.5%) were used. The results indicate that addition of nano-SiO2 and steel fibers decreases the workability of the concrete composites containing fly ash, and both the slump and slump flow decrease gradually with the increase in nano-SiO2 and steel fiber content. Besides, the addition of nano-SiO2 can greatly increase the flexural strength and flexural modulus of elasticity of concrete composites containing fly ash. There is a tendency for the increase in the flexural strength flexural modulus of elasticity with an increase in the nano-SiO2 content when the nano-SiO2 content is below 5%, while both of the two flexural parameters begin to decrease after the nano-SiO2 content above 5%. Furthermore, steel fibers have great improvement on the flexural properties of concrete composites containing fly ash and nano-particles. The flexural strength and flexural modulus of elasticity of concrete composites containing fly ash and nano-SiO2 are more than those of the concrete composite without steel fibers. Both of the two flexural parameters increase with the increase in steel fiber content when the steel fiber content is below 2%, while the flexural parameters begin to decrease after the steel fiber content is above 2%.

Punching Shear Capacity of Steel Fiber Reinforced Concrete Slab- Column Connections

2019 ◽  
Author(s):  
Josef Landler ◽  
Oliver Fischer
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Fiber Type ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Punching Shear ◽  
Slab Thickness ◽  
Shear Reinforcement ◽  
Fiber Reinforced

<p>To design flat slabs directly supported on columns, the punching shear resistance of the slab is a main factor. It can be increased in the vicinity of the slab-column connection with punching shear reinforcement, like bent up bars or shear studs, to bear the high reaction forces. However, the usage of punching shear reinforcement requires the knowledge of special design rules and often leads to problems and deficiencies in construction.</p><p>Fiber reinforced concrete seems to be a promising alternative to conventional punching shear reinforcement. To investigate the load bearing behavior of the slab-column connection using fiber reinforced concrete, a total of eight punching shear tests were performed. The specimens were realized with a typical top and bottom flexural reinforcement, but without punching shear reinforcement. Varied parameters were the slab thickness with 250 mm and 300 mm and the fiber content V<sub>f</sub> with 0.5 Vol.-% and 1.0 Vol.-%. To investigate the influence of modern fiber types, normal- and high-strength steel fibers with normal- and double-hooked-ends were used.</p><p>In all eight experimental tests, the intended punching shear failure was achieved. The capable load using fiber reinforced concrete increased by 20 % to 50 % compared to the reference tests without steel fibers, depending on the fiber type and the fiber content V<sub>f</sub>. Additionally, this load increase was accompanied by a significant improvement in ductility. The post-cracking behavior was noticeably influenced by the used steel fiber type. An influence of the slab thickness or steel fiber type on the shear strength contributed by the fiber reinforced concrete could not be determined.</p>

scholarly journals Vitality of Steel and Polypropylene Fibers in High Strength Concrete

2019 ◽  
Vol 8 (12) ◽  
pp. 4673-4676
Keyword(s):  
Thermal Insulation ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
Gradual Increase ◽  
High Strength ◽  
Fiber Content ◽  
Steel Fibers ◽  
Polypropylene Fibers ◽  
Strength Concrete ◽  
Concrete Mix

The main aim of this work was to investigate the influence of widely used steel fibers and polypropylene fibers on the concrete. From many studies it has been shown that, addition of fibers to the concrete has influenced the cracking of concrete, due to shrinkage, thermal insulation and bleeding of water. So, in this study we made use of ultra high strength concrete mix of M50, and we made use of both steel as well as polypropylene fibers to enhance the properties of the concrete. In this study total five concrete mixes were made with steel fiber in dosages of 2.5%, 2%, 1.5%, 1% and polypropylene fibers are in dosage 0%, 0.5%, 1%, 1.5% of the weight of concrete mix. The specimens were casted and all the specimens are tested for 7days and 28 days strength. The results have depicted a gradual increase in the strength of the concrete as the fiber content increased

scholarly journals The Effect and Associate Mechanism of Nano SiO2 Particles on the Diffusion Behavior of Water in Insulating Oil

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2373 ◽  
Author(s):  
Wenxin Tian ◽  
Chao Tang ◽  
Qian Wang ◽  
Shiling Zhang ◽  
Yali Yang
Keyword(s):  
Free Volume ◽  
Breakdown Voltage ◽  
Volume Fraction ◽  
Mean Square Displacement ◽  
Nano Particles ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Nano Sio2 ◽  
Insulating Oil ◽  
Sio2 Particles

Moisture has a significant effect on the internal insulation performance of transformers, and is closely related to the breakdown voltage of transformer insulating oil. In the present work, we studied the effect of nano-SiO2 particles on the diffusion of water in insulating naphthenic mineral oil using molecular dynamics simulation. Six models were established, three of which contained nano-SiO2 particles together with water concentration of 1 wt.%, 2 wt.%, or 3 wt.%. For each model variations in free volume, mean square displacement, and interaction energy were assessed. The addition of nano SiO2 particles was found to reduce the free volume fraction of the model and as well as the free motion of water molecules in the oil. These particles also increased the interaction between the oil and water molecules, indicating that insulating oil containing nano-particles has a greater binding effect on water. The diffusion coefficient of water in oil containing nano-SiO2 particles was reduced, such that water molecules were less likely to diffuse. The results also show that these particles adsorb water molecules in the oil and to reduce diffusion. Consequently, the addition nano-scale SiO2 particles could potentially improve the breakdown voltage of the insulating oil.

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

2020 ◽  
Vol 12 (2) ◽  
pp. 249-262 ◽  
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.

scholarly journals Assessment of the Effect of Replacing Normal Aggregate by Porcelinite on the Behaviour of Layered Steel Fibrous Self-Compacting Reinforced Concrete Slabs under Uniform Load

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ahmed S. D. AL-Ridha ◽  
Ali A. Abbood ◽  
Ali F. Atshan
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Normal Weight ◽  
Fiber Content ◽  
Steel Fibers ◽  
Concrete Slabs ◽  
Shear Mode ◽  
Uniform Load ◽  
Volume Fractions ◽  
Reinforced Concrete Slabs

In this research, an attempt has been made to study the effect of replacing all normal-weight aggregate “NWA” by lightweight aggregate “LWA” (having a volume equal to 60% of the volume of normal-weight aggregate) on the behaviour of layered steel fibrous self-compacting reinforced concrete slabs with various volume fractions of steel fiber under uniform area load using fine sand technique. The experimental work consists of two groups “NWA” and “LWA,” each group consists of three slab specimens (having an aspect ratio equal to the golden ratio, i.e., 1.618), the thickness of each slab is divided into two equal layers, the top layer is free from steel fibers, while the steel fibers exist only in the bottom layer with three volume fractions (0%, 0.4%, and 0.8%). Ultimate uniform load of the slabs decreases with the increase in steel fiber content, while the percentage of decrease in the bulk density remains rather constant. It was also found that the ultimate uniform load of the slabs in each group is significantly improved with increasing steel fiber content, and the percentage of this improvement is higher in lightweight concrete “LWC” than in normal-weight concrete “NWC” Finally, it was noticed that when steel fiber increased, the flexural strength of slabs increased higher than shear strength; therefore, the mode of failure has been changed from bending to shear mode for slabs of both groups “NWC” and “LWC.”

scholarly journals Relationship between Three-Dimensional Steel Fiber Statistics and Electromagnetic Shielding Effectiveness of High-Performance, Fiber-Reinforced Cementitious Composites

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5125
Author(s):  
Namkon Lee ◽  
Gijoon Park ◽  
Junil Pae ◽  
Juhyuk Moon ◽  
Sungwook Kim
Keyword(s):  
Electrical Conductivity ◽  
High Performance ◽  
Steel Fiber ◽  
Fiber Content ◽  
Steel Fibers ◽  
Electrical Network ◽  
Shielding Effectiveness ◽  
Contact Points ◽  
High Performance Fiber ◽  
Electromagnetic Shielding Effectiveness

This study aims to investigate the relationship between the steel fibers and the electromagnetic wave shielding effectiveness of a high-performance fiber-reinforced cementitious composite (HPFRCC). The distribution characteristics of the steel fibers and the variation of the electrical conductivity of HPFRCC as a function of the fiber content were quantified based on micro computed tomography (CT) and impedance measurements to determine their correlations with the electromagnetic shielding effectiveness. The impedance results showed that no electrical network was formed in the composite by the steel fibers and it is difficult to manufacture HPFRCC with high-electrical conductivity using steel fibers alone without CNTs or other carbon-based materials. For the steel fiber content of greater than 0.5%, the number of contact points between the steel fibers increased significantly, and the relationship between the fiber content and the number of contact points was observed. Despite the improvement of the electrical conductivity owing to the presence of the steel fibers and to the increase in the contact points between the steel fibers, the shielding effectiveness did not increase further for the steel fiber contents equal or above 1.5%. Consequently, it was found that the factor that controls the shielding effectiveness of HPFRCC is not the electrical network of the steel fibers, but the degree of the dispersion of the individual steel fibers.

scholarly journals A Study on Electro-Magnetic Properties of Concrete by Using Steel Fiber and Graphite

2021 ◽  
Vol 889 (1) ◽  
pp. 012073
Author(s):  
Abhishek Verma ◽  
Jagdeep Singh Gahir
Keyword(s):  
Electromagnetic Waves ◽  
Steel Fiber ◽  
Control Sample ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Steel Fiber Reinforced Concrete ◽  
Electrically Conductive ◽  
Concrete Mix ◽  
Electro Magnetic

Abstract This research paper describes the properties of electromagnetism of concrete mix that are sustained to make “Electrically Conductive Concrete”. Thus, the values provide various information on the behaviour of concrete mix and its relation with electromagnetic waves. Steel Fiber and Graphite are conductive materials. The properties of conductive concrete mix that is coarse aggregates, sand and cement can be measured. In the physical significance, the data calculated in X-ray diffraction and Scanning Electronic Microscope was discussed. The contact between the Steel Fiber and graphite is improved to make electrically conductive concrete. The strength is gained continuously till 3% where the maximum strength is gained which is 9.77% higher than the strength achieved by controlled sample. The control sample achieved 26.60MPa, with addition of 1% steel fibers the concrete achieved 29.40MPa, further increase in steel fiber content to 2% gained higher strength of 30.50MPa. The maximum compressive strength of 31.50MPa was achieved with the addition of 3% steel fibers. Further increase in steel fiber content resulted in decrease in strength, though 4% steel fiber reinforced concrete achieved 30.70MPa

Effect of Steel Fiber on the Performance of Concrete Materials

2012 ◽  
Vol 193-194 ◽  
pp. 337-340
Author(s):  
Shi Ping Zhang ◽  
Xiang Dong
Keyword(s):  
Frost Resistance ◽  
Steel Fiber ◽  
Plain Concrete ◽  
Steel Fibers ◽  
Experimental Results ◽  
Cracking Resistance ◽  
Concrete Materials

This paper presents the results of testing performed to evaluate the influence of steel fiber on the performance of concrete materials. The performance of concrete materials was studied through frost resistance, carbonation testing and restraint cracking testing. Experimental results show that the steel fibers can improve the frost resistance and carbonation of concrete, compared with plain concrete. Steel fibers can also reduce cracking, and improve the cracking resistance of concrete materials.

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