scholarly journals Rheological Behavior of High-Performance Shotcrete Mixtures Containing Colloidal Silica and Silica Fume Using the Bingham Model

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 428
Author(s):  
Kyong Ku Yun ◽  
Jong Beom Kim ◽  
Chang Seok Song ◽  
Mohammad Shakhawat Hossain ◽  
Seungyeon Han
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Colloidal Silica ◽  
Graphical Analysis ◽  
Mineral Admixture ◽  
Rheological Parameters ◽  
Bingham Model ◽  
New Material ◽  
The Cost ◽  
Strength And Durability

There have been numerous studies on shotcrete based on strength and durability. However, few studies have been conducted on rheological characteristics, which are very important parameters for evaluating the pumpability and shootability of shotcrete. In those studies, silica fume has been generally used as a mineral admixture to simultaneously enhance the strength, durability, pumpability, and shootability of shotcrete. Silica fume is well-known to significantly increase the viscosity of a mixture and to prevent material sliding at the receiving surface when used in shotcrete mixtures. However, the use of silica fume in shotcrete increases the possibility of plastic shrinkage cracking owing to its very high fineness, and further, silica fume increases the cost of manufacturing the shotcrete mixture because of its cost and handling. Colloidal silica is a new material in which nano-silica is dispersed in water, and it could solve the above-mentioned problems. The purpose of this research is to develop high-performance shotcrete with appropriate levels of strength and workability as well as use colloidal silica for normal structures without a tunnel structure. Thereafter, the workability of shotcrete with colloidal silica (2, 3, and 4%) was evaluated with a particle size of 10 nm and silica fume replacement (4 and 7%) of cement. In this study, an air-entraining agent for producing high-performance shotcrete was also used. The rheological properties of fresh shotcrete mixtures were estimated using an ICAR rheometer and the measured rheological parameters such as flow resistance and torque viscosity were correlated with the workability and shootability. More appropriate results will be focusing on the Bingham model properties such that the main focus here is to compare all data using the Bingham model and its performance. The pumpability, shootability, and build-up thickness characteristics were also evaluated for the performance of the shotcrete. This research mainly focuses on the Bingham model for absolute value because it creates an exact linear line in a graphical analysis, which provides more appropriate results for measuring the shotcrete performance rather than ICAR rheometer relative data.

scholarly journals Matrix Optimization of Ultra High Performance Concrete for Improving Strength and Durability

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6944
Author(s):  
Julio A. Paredes ◽  
Jaime C. Gálvez ◽  
Alejandro Enfedaque ◽  
Marcos G. Alberti
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Mercury Intrusion Porosimetry ◽  
High Performance Concrete ◽  
Silica Sand ◽  
Nano Silica ◽  
Ultra High Performance Concrete ◽  
Matrix Optimization ◽  
Binder Ratio ◽  
Strength And Durability

This paper seeks to optimize the mechanical and durability properties of ultra-high performance concrete (UHPC). To meet this objective, concrete specimens were manufactured by using 1100 kg/m3 of binder, water/binder ratio 0.20, silica sand and last generation of superplasticizer. Silica fume, metakaolin and two types of nano silica were used for improving the performances of the concrete. Additional mixtures included 13 mm long OL steel fibers. Compressive strength, electrical resistivity, mercury intrusion porosimetry tests, and differential and thermogravimetric thermal analysis were carried out. The binary combination of nano silica and metakaolin, and the ternary combination of nano silica with metakaolin and silica fume, led to the best performances of the UHPC, both mechanical and durable performances.

scholarly journals Enhancing the Hardened Properties of Recycled Concrete (RC) through Synergistic Incorporation of Fiber Reinforcement and Silica Fume

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4112 ◽  
Author(s):  
Babar Ali ◽  
Hawreen Ahmed ◽  
Liaqat Ali Qureshi ◽  
Rawaz Kurda ◽  
Hisham Hafez ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Silica Fume ◽  
High Performance ◽  
Synergistic Effects ◽  
Fiber Reinforcement ◽  
Recycled Concrete ◽  
Mineral Admixture ◽  
Portland Cement Concrete ◽  
Positive Role ◽  
Hardened Properties

Portland cement concrete is fragile in tension and it has numerous negative impacts on the environment. To deal with these issues, both fiber reinforcement and recycled materials can be utilized to manufacture sustainable and ductile concrete. In this study, the synergistic effects of high-performance mineral admixture silica fume and glass fiber reinforcement were investigated on the hardened properties of RC. For this purpose, two concrete mix families, namely, NC and RC were prepared. To understand the benefits of synergistic utilization of glass fiber and silica fume, in both NC and RC, 0.5% glass fiber was incorporated with three different levels of silica fume. i.e., 0%, 5%, and 10%. Both strength and permeability-related durability properties were investigated. Results revealed that combined incorporation of 0.5% fiber and 10% silica fume can help in the production of RC having better mechanical and durability performance compared to reference “NC”. Simultaneous incorporation of silica fume and glass fiber produces a combined effect greater than their individual effects on both mechanical and permeability properties of concrete. Silica fume plays a very dominant and positive role in the development of CS, WA, and CIPR of RC, whereas glass fiber plays a vital role in upgrading STS and FS of RC and whereas, with the addition of 0.5% glass fiber, RC can yield 8–9 times higher flexural toughness than that of the plain NC.

scholarly journals Incorporation of Carbon Fiber and Silica Fume in the Production of Conductive Concrete

2019 ◽  
Vol 7 (2) ◽  
pp. 17-21
Author(s):  
M. Purushothaman ◽  
◽  
K. Natarajan
Keyword(s):  
Electrical Conductivity ◽  
Silica Fume ◽  
Carbon Fibers ◽  
Low Voltage ◽  
Winter Season ◽  
Concrete Technology ◽  
Durability Properties ◽  
The Cost ◽  
Strength And Durability ◽  
Short Carbon

Concrete is regarded as a composite material that has good mechanical and durability properties for construction. However normal concrete is poor in electrical conductivity. An endeavour has been made with concrete to have all these three properties. The addition of small amounts of short carbon fibers and a nanomaterial silica fume to the concrete mixture causes an increase in strength and durability properties as well as electrical conductivity. In this paper, experimental results of compressive strength and electrical resistivity are presented. This Concrete technology can be applied with low voltage current for de-icing on highways and airfields, during snowfall in the winter season. This technique will help to reduce the cost and environmental issues of roads in snow fall region.

scholarly journals Matrix Optimization of Ultra High Performance Concrete for Improving Strength and Durability

2021 ◽  
Author(s):  
Julio Paredes ◽  
Jaime C. Gálvez ◽  
Alejandro Enfedaque ◽  
Marcos G. Alberti
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Mercury Intrusion Porosimetry ◽  
High Performance Concrete ◽  
Silica Sand ◽  
Nano Silica ◽  
Ultra High Performance Concrete ◽  
Matrix Optimization ◽  
Binder Ratio ◽  
Strength And Durability

This paper seeks to optimize the mechanical and durability properties of ultra-high performance concrete (UHPC). To meet this objective, concrete specimens were manufactured by using 1,100 kg/m3 of binder, water/binder ratio 0.20, silica sand and last generation of superplasticizer. Silica fume, metakaolin and two types of nano silica were used for improving the performances of the concrete. Additional mixtures included 13mm long OL steel fibers. Compressive strength, electrical resistivity, mercury intrusion porosimetry tests and differential and thermogravimetric thermal analysis were carried out. The binary combination of nano silica and metakaolin, and the ternary combination of nano silica with metakaolin and silica fume, led to the best performances of the UHPC, both mechanical and durable performances.

scholarly journals A Rheological Model for Evaluating the Behavior of Shear Thickening of Highly Flowable Mortar

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1011
Author(s):  
Mengyuan Li ◽  
Jianguo Han ◽  
Yuqi Zhou ◽  
Peiyu Yan
Keyword(s):  
Fly Ash ◽  
Yield Stress ◽  
Silica Fume ◽  
Rheological Model ◽  
Shear Thickening ◽  
Rheological Parameters ◽  
Bingham Model ◽  
Consistency Coefficient ◽  
Lubrication Layer ◽  
Binder Ratio

Neither the modified Bingham model nor the Herschel–Bulkley model can be used to characterize and calculate the performance of shear thickening of highly flowable mortar because of their incalculability of the rheological parameters. A new exponential rheological model was established to solve the characterization and calculation of shear thickening of the lubrication layer (highly flowable mortar) during the pumping of concrete in this paper. This new exponential rheological model has three rheological parameters, namely, yield stress, consistency coefficient, and consistency exponent. They can quantitatively describe the yield stress, differential viscosity, and shear thickening degree of highly flowable mortar. The calculating results of the rheological parameters of the newly established model for the mortars with different compositions showed that the consistency exponent of mortar decreased with the increase of its sand-binder ratio or the dosage of fly ash in the binder. This indicates that the shear thickening degree of mortar decreases. The consistency exponent of mortar initially decreases and subsequently increases with the increase in silica fume content or the dosage of the superplasticizer. It illustrates that the degree of the shear thickening of mortar initially decreased and subsequently increased. These varying patterns were confirmed by the rheological experiment of mortars.

Literature Review: Mechanical Properties of Hardened Silica Fume Concrete

2014 ◽  
Vol 1008-1009 ◽  
pp. 1357-1362
Author(s):  
Xi Xi He ◽  
Qing Wang
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Ion ◽  
High Strength ◽  
Penetration Resistance ◽  
Pozzolanic Reaction ◽  
Mineral Admixture ◽  
Chemical Attack ◽  
Chloride Ion Penetration

Silica fume (SF) has become an environmental mineral admixture in the production of high-strength and high-performance concrete in modern concrete engineering. Through compacting all components and pozzolanic reaction, obvious mechanical enhancement of concrete is observed in the aspects of compressive strength tensile strength, elastic modulus as well as fracture toughness. Further more, durability improvement of silica fume concrete such as chloride-ion penetration resistance and chemical attack resistance are reported accordingly.

High Performance Materials Development in the 21st Century: Trends and Directions

2004 ◽  
Vol 449-452 ◽  
pp. 7-12
Author(s):  
James C. Williams
Keyword(s):  
Material Properties ◽  
Gas Turbines ◽  
High Performance ◽  
Matrix Composites ◽  
New Materials ◽  
Materials Development ◽  
Recent Developments ◽  
New Material ◽  
Time Required ◽  
The Cost

Product performance including the cost of ownership is becoming increasingly dependent on the availability of high quality, high performance, affordable materials of construction. Today, the requirements placed on a new material for a high performance structural application extend well beyond the improvement of one or more material properties. This makes the introduction of a new material a multi-faceted activity. Modern structural materials derive their performance from a combination of composition and processing, the results of which are inextricably intertwined. This statement pertains to both metallic alloys and to fiber reinforced composite materials. In addition, material cost and the reproducibility of material properties are becoming more central as acceptance criteria for incorporating new materials into new products. This paper will use examples of recent developments in materials for aircraft gas turbines to depict the materials introduction process. Some of these developments have been successful and others have not. These examples illustrate the changing picture that represents the successful introduction of a new structural material, even in a high performance, high value product such as a gas turbine. Specific examples will include metal matrix composites, Ni-base alloys and improved reliability Ti alloys. The basis for successful introduction, or lack thereof will be discussed. While the examples are specific to gas turbines, they are generally instructive and depict the growing complexity of the process of developing and introducing new materials into a high value product. An additional issue for all new materials introduction is the time required to achieve product readiness. As the time required for product design decreases, there has been little commensurate reduction in materials development cycle time. This matter also will be discussed and some possible reasons and potential solutions will be described.

Influence of Silica Fume on Mechanical Property of High Performance Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1482-1485 ◽  
Author(s):  
Yun Feng Li ◽  
Jian Zhu ◽  
Li Xu
Keyword(s):  
Mechanical Property ◽  
Silica Fume ◽  
High Performance ◽  
Volcanic Ash ◽  
High Performance Concrete ◽  
Physical Structure ◽  
Experimental Results ◽  
Silicon Material ◽  
Strength And Durability ◽  
Durability Of Concrete

Silica fume is a by-product in the production of ferrosilicon and industrial silicon material. With the ultrafine physical structure of and high volcanic ash activity, silica fume is more important admixture in concrete improving the strength and durability of concrete, and it is widely used in high performance concrete engineering. Influence of silica fume on mechanical property of high performance concrete is investigated in this paper. Experimental results show that the strength of concrete increases significantly when suitable dosages of admixtures is applied.

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