Effect of water-to-binder ratio on the hydration kinetics of composite binder containing slag or fly ash

To investigate the effect of water-to-binder ratio and fly ash content on the properties of bendable concrete, we prepared four samples of different strength grades with water-to-binder ratios of 0.25 and 0.30 and fly ash contents of 60% and 80%. The effects of water-to-binder ratio and fly ash content on the compressive strength, flexural strength, elastic modulus, fracture toughness, and uniaxial tensile deformation of the samples were investigated. The results show that the strength of bendable concrete can be varied by varying the water-to-binder ratio and fly ash content. Water-to-binder ratio and fly ash content showed almost the same effect on fracture toughness, whereas fly ash content exhibited a greater effect on elastic modulus. With an increase in water-to-binder ratio and fly ash content of concrete, the initial crack stress and tensile strength decreased and the ultimate tensile strain increased, but the change of water-to-binder ratio showed a more significant effect on the ultimate tensile strain.

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Effect of Fly Ash and Nano-CaCO3 on the Viscosity of Cement Paste

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.357-360.968 ◽

2013 ◽

Vol 357-360 ◽

pp. 968-971 ◽

Cited By ~ 2

Author(s):

Ren Juan Sun ◽

Zhi Qin Zhao ◽

Da Wei Huang ◽

Gong Feng Xin ◽

Shan Shan Wei ◽

...

Keyword(s):

Fly Ash ◽

Cement Paste ◽

Bingham Model ◽

Reduced Viscosity ◽

Binder Ratio ◽

Water To Binder Ratio

The effect of fly ash and nanoCaCO3 on the viscosity of pastes was studied. The rheological value of cement paste was determined by the rotation rheometer NXS-11B. In the study, five different dosages (0%, 20%, 30%, 40%, and 50%) of fly ash and three levels of nanoCaCO3, 0.5%, 1%, and 2.5%, were considered. Viscosity of the pastes, made with fly ash and nanoCaCO3 at a constant water-to-binder ratio of 0.35, were measured and analyzed. The results indicate that the pastes with fly ash or/and nanoCaCO3 still fit the Bingham model. The addition of fly ash reduced viscosity, however, the addition of nanoCaCO3 increased viscosity. The effect of nanoCaCO3 is more significantly than fly ash on viscosity.

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High Performance Concrete with Ternary Binders

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.761.120 ◽

2018 ◽

Vol 761 ◽

pp. 120-123 ◽

Cited By ~ 1

Author(s):

Vlastimil Bílek ◽

David Pytlík ◽

Marketa Bambuchova

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Silica Fume ◽

High Performance ◽

Ordinary Portland Cement ◽

High Performance Concrete ◽

Fresh Concrete ◽

Binder Ratio ◽

Water To Binder Ratio ◽

Condensed Silica Fume

Use a ternary binder for production of a high performance concrete with a compressive strengths between 120 and 170 MPa is presented. The water to binder ratio of the concrete is 0.225 and the binder is composed of Ordinary Portland Cement (OPC), condensed silica fume (CSF), ground limestone (L), fly ash (FA) and metakaoline (MK). The dosage of (M + CSF) is kept at a constant level for a better workability of fresh concrete. Different workability, flexural and compressive strengths were obtained for concretes with a constant cement and a metakaoline dosage, and for a constant dosage (FA + L) but a different ratio FA / L. An optimum composition was found and concretes for other tests were designed using this composition.

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Effects of Expansive Agents on the Early Hydration Kinetics of Cementitious Binders

Materials ◽

10.3390/ma12121900 ◽

2019 ◽

Vol 12 (12) ◽

pp. 1900 ◽

Cited By ~ 2

Author(s):

Miao Miao ◽

Qingyang Liu ◽

Jian Zhou ◽

Jingjing Feng

Keyword(s):

Fly Ash ◽

Hydration Heat ◽

Mineral Admixture ◽

Mineral Admixtures ◽

Hydration Reaction ◽

Hydration Kinetics ◽

Early Hydration ◽

Expansive Agent ◽

Mechanical Performances ◽

Kinetics Of

The addition of expansive agents could overcome the main disadvantages of raw concrete including high brittleness and low tensile strength. Few studies have investigated the early hydration kinetics of expansive cementitious binders, though the findings from the early hydration kinetics are helpful for understanding their technical performances. In this study, mixtures of 3CaO•3Al2O3•CaSO4 and CaSO4 (i.e., ZY-type™ expansive agent) with different proportions of mineral admixtures (e.g., fly ash and slag) were added into cement pastes to investigate the early hydration kinetics mechanism of expansive cementitious binders. Early hydration heat evolution rate and cumulative hydration heat were measured by isothermal calorimeter. Kinetic parameters were estimated based on the Krstulovic–Dabic model and Knudsen equations. Mechanical performances of expansive cementitious binders were tested in order to evaluate if they met the basic requirements of shrinkage-compensating materials in technical use. The early hydration heat released from cementitious binders containing ZY-type™ expansive agent was much greater than that released by pure cement, supporting the idea that addition of the expansive agent would improve the reaction of cement. The early hydration kinetic rates were decreased due to the reactions of the mineral admixture (e.g., fly ash or slag) and the ZY-type™ expansive agent in the cement system. The hydration reaction of cementitious binders containing ZY-type™ expansive agent obeyed the Krstulovic–Dabic model well. Three processes are involved in the hydration reaction of cementitious binders containing ZY-type™ expansive agent. These are nucleation and crystal growth (NG), interactions at phase boundaries (I), and diffusion (D). The 14-day expansion rates of cementitious binders containing ZY-type™ expansive agent are in the range of 2.0 × 10−4 to 3.5 × 10−4, which could meet the basic requirements of anti-cracking performances in technical use according to Chinese industry standard JGJ/T 178-2009. This study could provide an insight into understanding the effects of expansive agents on the hydration and mechanical performances of cementitious binders.

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Analysis of the Effect of Fly Ash on Compressive Strength of Concrete Using Neural Network and Parameter Analysis

Materials Science Forum ◽

10.4028/www.scientific.net/msf.995.130 ◽

2020 ◽

Vol 995 ◽

pp. 130-135

Author(s):

Xiao Yong Wang

Keyword(s):

Neural Network ◽

Compressive Strength ◽

Fly Ash ◽

Network Model ◽

Neural Network Model ◽

Parameter Analysis ◽

Replacement Ratio ◽

The Neural Network ◽

Binder Ratio ◽

Water To Binder Ratio

Compressive strength is a crucial design index of fly ash blended concrete. This study presents an estimation model to show the effect of fly ash on the strength development of concrete. First, a neural network model is proposed to estimate the compressive strength of fly ash blended concrete. The input variables of the neural network are water-to-binder ratio, fly ash replacement ratio, and curing ages. The output result of the neural network is a strength. The range of water-to-binder ratio is from 0.3 to 0.5, the range of fly ash replacement ratio is from 0 to 0.55, and the range of test age is from 3 days to 180 days. The neural network gives an accurate evaluation of compressive strength. Second, parameter analysis is carried out based on the neural network model. The results of parameter analysis show that the effect of fly ash on strength is dependent on water-to-binder ratio. The using of high-volume fly ash with low water-to-binder ratio concrete is a rational option.

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Influence of Fly Ash on Abrasion Resistance of Concretes with their Additions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.592-593.651 ◽

2013 ◽

Vol 592-593 ◽

pp. 651-654

Author(s):

Aneta Nowak-Michta

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Abrasion Resistance ◽

Test Results ◽

Reference Test ◽

Binder Ratio ◽

Alternative Test ◽

Water To Binder Ratio ◽

Standard Tests ◽

Class F

The influence of fly ash quality and quantity on abrasion resistance of hardened concretes with siliceous fly ash addition is analysed in the paper. Abrasion resistance was measured in two standard tests according to EN 1338: 2005: reference test of the Wide Wheel and alternative test of the Bohme. Cement was replaced with 20, 35, and 50% of Class F siliceous fly ash in three categories of losses of ignition A, B and C by mass. The water to binder ratio, the air-entraining and the workability of mixtures were maintained constant at 0.38, 4.5% and 150 mm respectively. Test results indicated that in both methods, all tested concretes according to EN 1338: 2005 could be classified to 4-the highest class of abrasion resistance. In reference test of the Wide Wheel fly ash quality and quantity not influences abrasion resistance. However, in alternative, Böhme test abrasion resistance lowering with growth quantity of fly ash in binder, while loss of ignition of fly ash no influenced abrasion resistance. There were no correlation between the abrasion resistance and the compressive strength.

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