scholarly journals The Effect of Incorporating Ultra-Fine Spherical Particles on Rheology and Engineering Properties of Commercial Ultra-High-Performance Grout

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1040
Author(s):  
Wei-Ting Lin ◽  
Wen-Que Zhao ◽  
Yi-Hua Chang ◽  
Jiann-Shi Yang ◽  
An Cheng
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
High Performance ◽  
Hunan Province ◽  
Engineering Properties ◽  
Spherical Particles ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Volume Stability

In this study, ultra-fine spherical particles of silica fume and reactive ultra-fine fly ash were added to a mixture of commercial ultra-high-performance grout (UHPG) with the aim of enhancing the rheological properties, compressive strength, compactness, and permeability. This commercial UHPG study was conducted in collaboration with Triaxis Corporation (Changsha city, Hunan province, China). A water-to-binder ratio of 0.21 and a binder-to-fine aggregates ratio of 1.17 were used as fixed parameters, and the binders were a combination of type-II Portland cement, sulphoaluminate cement, silica fume, and reactive ultra-fine fly ash (RUFA). Polycarboxylate superplasticizer powder was used to control the rheology. The results revealed excellent compressive strength, volume stability, and resistance to chloride penetration. Mercury intrusion porosimetry and scanning electron microscopy tests revealed that the medium-sized RUFA particles with small silica fume particles completely filled the spaces between large cement particles to achieve optimal densification. This mixture also produced dense hydration and calcium-silicate-hydrates colloids, which filled the microstructures of the UHPG resulting in excellent engineering properties and durability. This commercially available UHPG mix responded to excellent compressive strengths approaching 120 MPa and exhibited good workability with a loss of slump-flow rate up to 33% after 60 min. It also exhibited very low abrasion resistance (0.5%), stable shrinkage and expansion rates (stabilization over 10 days), very low chloride diffusion coefficient (less than 0.1 × 10−14 m2/s) with a denser microstructure. This commercial UHPG (UHPG-120) has been developed to meet the needs of the market.

scholarly journals Engineering Properties of Ternary Cementless Blended Materials

2020 ◽  
Vol 10 (3) ◽  
pp. 191-199
Author(s):  
Wei-Ting Lin ◽  
Kinga Korniejenko ◽  
Marek Hebda ◽  
Michał Łach ◽  
Janusz Mikuła
Keyword(s):  
Compressive Strength ◽  
Diffusion Coefficient ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Engineering Properties ◽  
Chloride Diffusion ◽  
Total Charge ◽  
Chloride Diffusion Coefficient ◽  
Furnace Slag

A new non-cement blended materials is developed as a full replacement of cement without alkali activator. This study was conducted to explore a suitable method for activating new ternary green materials with desulfurization gypsum, water-quenched blast-furnace slag and co-fired fly ash from circulating fluidized bed combustion as non-cement inorganic binder. Test subject was included flowability, compressive strength, absorption, total charge-passed from rapid chloride permeability test, chloride diffusion coefficient from accelerated chloride migration test and SEM observation. Test results indicate that a ternary mixture containing 1% desulfurization gypsum, 60% water-quenched blast-furnace slag and 39% co-fired fly ash was a suitable development in compressive strength. The new non-cement blended materials were performed a well compressive strength, lower absorption, and lower chloride diffusion coefficient. In addition, the compressive strength decreased as the inclusion of desulfurization gypsum increased. It was concluded that using desulfurization gypsum alone decreased the setting time and compressive strength. SEM micrographs were verified the development in compressive strength originated from the C-S-H and C-A-S-H gel produced by Ca(OH)2, SiO2, and Al2O3.

Production of High-Performance Composite Concrete Segment and Experimental Investigation of Materials

2010 ◽  
Vol 168-170 ◽  
pp. 1042-1045
Author(s):  
Ying Li Gao ◽  
Bao Guo Ma
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
High Performance ◽  
Concrete Cover ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Volume Deformation ◽  
Volume Stability ◽  
High Performance Composite ◽  
Structure Layer

Tunnel lining concrete segment is the most critical and important structural member of shield tunneling. This investigation designed and produced high-performance composite concrete segment (HCCS). Some key indexes that affect the properties of segment were tested, such as impermeability, volume stability, mechanical property, etc. The results indicated that the impermeability of HCCS concrete cover was excellent and the chloride diffusion coefficient decreased one order of magnitude compared to that of the ordinary segment concrete cover, while the service-life of HCCS increased more than ten-fold. The volume stability of HCCS concrete cover and concrete structure layer were good and the better compatibility in the volume deformation of the whole structure was shown. Furthermore, the mechanical properties of concrete cover and concrete structure layer met the project requirement perfectly, ensuring the higher durability and longer service-life of HCCS effectively.

Development of High Performance Concrete Containing Admixture in Nuclear Power Plants

2013 ◽  
Vol 357-360 ◽  
pp. 1062-1065 ◽  
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Song Hui Yun ◽  
Do Gyeum Kim ◽  
Jea Myoung Noh
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Modulus Of Elasticity ◽  
Blast Furnace Slag ◽  
High Performance ◽  
Splitting Tensile Strength ◽  
Furnace Slag

This paper presents the results of an experimental study on the compressive strength, splitting tensile strength and modulus of elasticity characteristics of high performance concrete. These tests were carried out to evaluate the mechanical properties of HPC for up to 7 and 28 days. Mixtures were prepared with water to binder ratio of 0.40. Two mixtures were containing fly ash at 25%, silica fume at 5% cement replacement, respectively. Another mixture was contains blast furnace slag and fly ash at 25%. Three standard 100¥a200 cylinder specimens were prepared. HPC showed improvement in the compressive strength and splitting tensile strength when ordinary Portland cement was replaced with silica fume. Compare with specimens FA25 and BS25FA25, specimen SF5 showed much more modulus of elasticity. It shows that the use of the blast furnace slag of 25% and fly ash of 25% cement replacement has caused a small increase in compressive strength and splitting tensile strength and modulus of elasticity compared to the only use of fly ash of 25% at 28days. The results indicated that the use of blast furnace slag or silica fume provided the good performance compare to fly ash when the mechanical properties of the high performance concretes were taken into account.

scholarly journals Composition and selected properties of low pH mortars and concretes for radioactive waste repositories

2020 ◽  
Vol 322 ◽  
pp. 01033
Author(s):  
An Cheng ◽  
Wei-Ting Lin ◽  
Sao-Jeng Chao ◽  
Hui-Mi Hsu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Spent Nuclear Fuel ◽  
Cementitious Materials ◽  
Low Ph ◽  
Engineering Properties ◽  
Filling Materials ◽  
Radioactive Waste Repositories ◽  
Waste Repositories

Conventional cementitious materials as tunnel supporting materials are utilised in the construction of the final repository for spent nuclear fuel. However, the use of cementitious material releases alkaline ions from pH12 to pH13 plumed into groundwater. Such a high pH is detrimental to the performance of the bentonite functioning, which may possibly enhance the dissolution and alteration of the fracture buffer and filling materials. Instead, low-pH cementitious materials are being developed for use in geological repositories. This study is aimed at evaluating the usability of low-pH cementitious materials containing 40% silica fume or composites blended with 20% silica fume and 40% fly ash. Engineering properties were analysed and verified through experimental research using the flow, compressive strength, pH measurement and hydraulic conductivity. Test results show that the replacement level with 40% of silica fume or 20% of silica fume and 40% of fly ash was suitable for the mixture of low-pH cementitious. Compared to the compressive strength and water permeability of ordinary cementitious, those of low-pH cementitious enhanced better engineered performances at the age of 91 days. The information is contributed us to establish the long-term durability and environmental requirements of disposal repositories in Taiwan.

Experimental Study on the Chloride Diffusivity of Recycled Aggregate Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1404-1408
Author(s):  
He Ying Qin ◽  
Yan Lin Zhao ◽  
Bo Guang Luo ◽  
Yi Hu Chen
Keyword(s):  
Diffusion Coefficient ◽  
Fly Ash ◽  
Silica Fume ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Chloride Diffusion ◽  
Partial Replacement ◽  
Chloride Diffusion Coefficient ◽  
Aggregate Concrete ◽  
Chloride Diffusivity

The study presented herein has been carried out in order to investigate the chloride diffusivity of recycled aggregate concrete (RAC). Meanwhile, the effect of the binder type, involving cement replacement materials such as, fly ash, slag and silica fume on the chloride diffusivity has also been investigated. For this purpose, RAC and concrete containing the different type of binders with w/b ratios of 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60 were used. As a result, the chloride diffusion coefficient of RAC is higher than that of natural concrete and the partial replacement of cement with fly ash, slag and silica fume is effective in decrease in the chloride diffusion coefficient, measured by a rapid chloride conductivity test.

scholarly journals Study on the Influence of fly ash, mineral powder and silicon powder on the performance of high-performance concrete

2021 ◽  
Vol 237 ◽  
pp. 03018
Author(s):  
Hua-Quan Yang ◽  
Xue-Ying Liu ◽  
Xiao-Dong Chen
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Orthogonal Experiment ◽  
Setting Time ◽  
Silicon Powder ◽  
Optimal Dosage ◽  
Mineral Powder

To study the effect of fly ash, mineral powder, and silica fume on the working performance and mechanical properties of C70 high-performance concrete by adding the same amount of fly ash, granulated blast furnace slag powder, and silica fume as a composite admixture to replace the amount of cement. Influencing the law, at the same time, the optimal dosage ratio of various admixtures is determined through the orthogonal experiment. The results show that: when adding 6% silica fume, it can improve the performance of high-performance concrete. When the amount is increased, the viscosity of the concrete increases and the fluidity decreases. Incorporating an appropriate amount of silica fume can greatly increase the compressive strength of concrete. When blended with fly ash in the proportion of 20%, the performance of high-performance concrete is better. When the same amount of fly ash replaces cement, fly ash reduces hydration and improves the cohesion of concrete, 7d, 28d the compressive strength of the cube increases significantly. Adding 10% mineral powder, mineral powder can affect the early compressive strength of highperformance concrete, extend the setting time of concrete, and improve the pumping capacity of concrete.

Application of High Performance Concrete with Compound Admixtures of Fly Ash and Perlite Powder in Pavement of Highway

2011 ◽  
Vol 413 ◽  
pp. 29-33 ◽  
Author(s):  
Le Hua Yu ◽  
Hui Ou ◽  
Shuang Xi Zhou
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Technical Specification ◽  
Chloride Ion ◽  
Aluminosilicate Glass ◽  
Chloride Diffusion ◽  
Chloride Salt ◽  
Chloride Diffusion Coefficient

Based on former experimental achievement in laboratory, application and construction of high performance concrete (HPC) in pavement of highway were introduced to the paper. The HPC was proportioned with compound admixtures of 12% fly ash and 12% perlite powder replacing cement in equal mass. Perlite powder of both is a new mineral admixture, originated natural volcanic rock perlite composed of mainly aluminosilicate glass, was ground to mostly under 45 μm so as to possess pozzolanic activity, and then added to concrete as a supplementary cementitious material to substitute for partial cement. Multiplex of the two admixtures is profitable to increase workability, mechanical properties and durability during post-stage for concrete in varying degrees. The testing slump and construction fit of the fresh concrete in situ were shown that both of admixtures improved workability of the concrete. HPC samples remained in field and drilled from pavement were determined and investigated on mechanical properties and durability by means of test. It has been observed by inspected result of that flexural strength of these concrete are above 5 MPa at 28 cured days and compression strength about 40 MPa. The indexes of their abrasion resistance distribute throughout 1.94—2.63 kilo-rotation/mm at 90 days. These measured mechanical characteristics are so large enough to the technical specification of heavy traffic grade highway on mechanical property. To investigate durability of the HPC, the charge passed and the chloride diffusion coefficient in concrete at 90 cured days obtained from the accelerated chloride migration test were determined with RCM experimental equipment. The values of charge passed in the concrete were lower and ranged in 449—928 Coulomb, which revealed that the HPC are also better permeability resistance of chloride ion and be able to sustain in environment of chloride salt for 100 years. The chloride diffusion coefficients of the HPC were scattered in 1.4—4.7×10-12m2s-1. These parameters exhibited completely the HPC better or excellent for electrical indication of concrete’s ability to resist chloride ion penetration referent to relevant standards and information.

Behavior of High Performance PVA Fiber Reinforced Cement Composites under Uniaxial Compressive Load

2012 ◽  
Vol 174-177 ◽  
pp. 687-691 ◽  
Author(s):  
Yan Li ◽  
Ze Jun Liu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
High Performance ◽  
Peak Stress ◽  
Fiber Content ◽  
Experimental Program ◽  
Fiber Reinforced ◽  
Reinforced Cement ◽  
Pva Fiber

Abstract. Based on an extensive experimental program, the paper studies the behavior of High Performance Fiber Reinforced Cement Composite (HPFRCC) under Uniaxial compression. The experimental parameters are: PVA fiber content by volume, fly ash and silica fume content. The compressive strength, peak strain as well as compressive stress-strain curves are obtained. The test results reveal that PVA fibers can greatly improve plastic deformation ability of HPFRCC, especially have significant impact on ductility after the peak stress, though fiber content has small influence on compressive strength. With the increase of fly ash content, peak stress of HPFRCC decreases, but toughness increases. 10% silica fume content has not obvious effect on compressive strength for HPFRCC with large quantities of fly ash , but leads to less ductile behavior.

Influence of Different Curing Days on Mechanical Properties of Concrete with Admixtures of Fly Ash, Blast Furnace Slag and Silica Fume

2013 ◽  
Vol 405-408 ◽  
pp. 2843-2846
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Sun Woong Kim ◽  
Do Gyeum Kim ◽  
Myung Sug Cho ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
High Performance ◽  
High Performance Concrete ◽  
Furnace Slag

High performance concrete (HPC) can be made with cement alone or any combination of cement and mineral components, such as, blast furnace slag, fly ash, silica fume, kaolin, rice husk ash, and fillers, such as limestone powder [. In this study, three mixes of high performance concrete (HPC) with same water-binder ratio and different types of mineral admixtures were prepared. he compressive strength, splitting tensile strength and modulus of elasticity values were measured in accordance with the ASTM. The influence of fly ash (FA), blast furnace slag (BS) and silica fume (SF) on mechanical properties of HPC were compared and analyzed. Their mechanical properties are measured at 7 days and 28 days. The results showed that specimen BS45+SF5 performed better than specimens BS30+FA25+SF5 and BS65+SF5 for the compressive strength, splitting tensile strength and modulus of elasticity.

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