Five fly ash concretes were found to gain considerable strength beyond 28 days when standard cured in water at 20ยฐC. However, strength development came to an almost complete stop after 3ยฝ years, at what time the fly ash activity factors with respect to concrete compressive strength ranged from 0.86
Sulfate resistance of high fly ash content concrete
โ Scribed by K. Torii; K. Taniguchi; M. Kawamura
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 780 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0008-8846
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โฆ Synopsis
Changes in length, compressive strength, dynamic modulus of elasticity and pulse velocity of high fly ash content concrete with replacement levels of up to 50 % when completely immersed in the IO % Na2S04 solution were periodically measured for 2 years.
It was found from the measurements of mechanical properties that the 50 % replacement by fly ash was very effective in the improvement of the sulfate resistance of concrete.
During 2 years of exposure to the 10 % Na2S04 solution, high fly ash content concrete with the binder content of 400 kg/m3 and with replacement level of 50 % was steadily gaining the compressive strength, and no detectable deterioration was observed.
Chemical analysis data also showed that the excellence of high fly ash content concrete in the sulfate resistance was attributed primarily to the prevention of ingress of sulfate ions into concrete, resulting in little formation of gypsum and/or ettringite in concrete.
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