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Title |
Evaluation of Relationship between Strength and Resistance to Chloride in Concrete Containing Fly Ash with Ages
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Authors |
윤용식(Yong-Sik Yoon) ; 박재성(Jae-Sung Park) ; 황철성(Chul-Sung Hwang) ; 권성준(Seung-Jun Kwon) |
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DOI |
https://doi.org/10.11112/jksmi.2017.21.4.053 |
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Keywords |
핵심용어: 염소 이온 ; 플라이애시 ; 염화물 확산계수 ; 통과 전하량 ; 압축강도 Chloride ion ; Fly ash ; Chloride diffusion coefficient ; Amount of passed charge ; Compressive strength |
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Abstract |
Fly ash(FA) which is a byproduct in the coal combustion in thermal power plant contributes to pore structure densification due to pozzolanic reaction, and this leads to long-term strength development and excellent resistance to chloride penetration. In the work, compressive strength and chloride resistance in OPC(Ordinary Portland Cement) and FA-based concrete are evaluated, and the relationships are investigated considering ages. For the work, 3 different W/B (Water to Binder) ratios of 37%, 42% , and 47% are prepared, and 3 substitution ratio of fly ash(0%, 30% , and 50%) are considered as well. At the age of 28 days and 180 days, test results of compressive strength, diffusion coefficients based on Tang's method, and passed charges referred to ASTM C 1202 and KS F 2711 are obtained. With increasing replacement ratio of FA and decreasing W/B, the resistances to chlorides(diffusion coefficient and passed charge) are improved, and the results at the age of 180 days decrease to only 15% level at the age of 28 days due to pozzolanic reaction in FA 50 mixture, which shows that resistance to chloride is much dependent on age effect than strength development. After 180 days, more clear linear relationships are observed between strength and resistance to chloride.
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