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Based on fractal theory HVFAC abrasion properties

Author: GuoFeng
Tutor: DuYingJi
School: Northwest University of Science and Technology
Course: Hydraulic Structure Engineering
Keywords: Underwater Ball Method Compressive strength Abrasion strength Fractal Box counting method
CLC: TU521.4
Type: Master's thesis
Year: 2010
Downloads: 39
Quote: 1
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Abstract

Fly ash is a very fine particles can be in the air flow of industrial waste, a huge annual emissions, cause serious environmental pollution. However, with the fly ash which is applied to the concrete, as an admixture, which not only improves the overall performance of the concrete, but also to reduce the burden on the environment. With the high volume fly ash concrete is applied to the concrete structure, the maximum degree of substitution of fly ash cement, with good economic, social and environmental benefits. In this paper, a project in Ningxia research on high volume fly ash concrete abrasion performance of a pilot study, to meet the engineering application of the premise, through the effect of the different fly ash concrete abrasion performance, and using Fractal box counting method the test results were analyzed and studied, and finally presents the best engineering applications require concrete mix. The study reached the following main results: (1) When the concrete content of fly ash is less than 50%, the compressive strength of concrete with fly ash content increases; when fly ash in concrete less than 50% ash, fly ash concrete compressive strength increases with decreasing; 60d instar high volume fly ash concrete compressive strength greater than 28d age high volume fly ash concrete compressive strength. (2) When the content of fly ash is less than 50%, with the increase of fly ash concrete wear rate decreases; when the content of fly ash greater than 50%, with the fly ash increase in dosage, increasing the wear rate of the concrete; 28d age of concrete 60d wear rate greater than the wear rate of the concrete. (3) in the concrete superplasticizer admixture 1% and 0.6 / thousands of air-entraining agents, concrete compressive strength and abrasion strength are to a certain extent. (4) When the content of fly ash is less than 40%, with the fly ash content increases, the fractal dimension decreases abrasion of concrete strength increases; when the content of fly ash greater than 40%, the As the fly ash content increases, the fractal dimension increases, the concrete strength but reduces abrasion. (5) 28d instar Concrete: When fly ash is 40%, the fractal dimension is 2.028, the maximum strength of concrete abrasion; 60d instar Concrete: When fly ash is 40%, the score dimension is 2.021, the maximum intensity of concrete abrasion; 28d age concrete fractal dimension greater than 60d age concrete fractal dimension. (6) When the content of fly ash in between 40% to 60% of the specimens in the worn surface fractal dimension between 2.025 ~ 2.029, concrete abrasion strength most appropriate. (7) combined with the needs of the project, it is recommended to use high volume fly ash concrete works best with the ratio of 1:2.13:3.42:0.65 (W: C: F: W / B), content of fly ash 50% (excess factor of 1.3).

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