Influence of Mixture Proportion and Curing Condition on Contribution of Fly Ash to Strength of Concrete
Influence of Mixture Proportion and Curing Condition on Contribution of Fly Ash to Strength of Concrete
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DOI：
10.4028/www.scientific.net/kem.302-303.235
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发表时间：
2005-12
期刊：
影响因子：
--
通讯作者：
F. Wu;Y. Masuda;S. Nakamura;S. Sato
中科院分区：
文献类型：
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作者：
F. Wu;Y. Masuda;S. Nakamura;S. Sato
为了研究粉煤灰在混凝土中的强度效率，采用公式计算了粉煤灰对强度的贡献，k值为：粉煤灰混凝土与不掺粉煤灰的对照混凝土之间因粉煤灰掺量不同而产生的强度差除以两种不掺粉煤灰的对照混凝土之间因水泥掺量不同而产生的强度差，即前者与后者之差。k值与粉煤灰比表面积、混凝土养护条件和试件龄期有关。根据1981年至2003年日本出版的多份论文和期刊中收集的大量数据，研究了粉煤灰性质、配合比和养护条件对k值的影响。在研究范围内，观察到以下情况：（1）当粉煤灰混凝土保持潮湿养护时，在91天及以后的龄期，比表面积为250至500 m2/kg的粉煤灰的k值平均为0.5至0.6或更高，而比表面积为150至250 m2/kg的粉煤灰的k值为0.4至0.5左右，并且在某些情况下对强度贡献很小。(2)在波特兰水泥含量为250至450 kg/m3的范围内，强度贡献倾向于随着水泥含量的增加而增加。(3)在标准养护条件下，粉煤灰对91 d和364 d强度的贡献分别是28 d强度的1.44 ~ 1.97倍，而在空气养护条件下，粉煤灰对28 d强度的贡献则是28 d强度的0.75 ~ 0.79倍。
To investigate the strength efficiency of fly ash in concrete, the contribution of fly ash to strength, k value was calculated with the equation: the strength difference between fly ash concrete and control concrete with no fly ash due to the different fly ash content divides by the strength difference between both control concrete with no fly ash due to the different cement content which equals to the former different fly ash content. The k values were organized with fly ash specific surface area, concrete curing condition and age of specimens. Based on a large number of data collected from several proceedings and journals published in Japan during 1981 to 2003, the influences of fly ash property, mixture proportion and curing condition on k value were investigated. Within the range of study the following observations were made: (1) When fly ash concrete kept in moist curing, the k value of fly ash with specific surface area from 250 to 500 m2/kg is averagely 0.5 to 0.6 or higher at an age of 91 days and later, whereas that of fly ash with specific surface area from 150 to 250 m2/kg is around 0.4 to 0.5, and with some cases contributing little to the strength. (2) In the range of a portland cement content of 250 to 450 kg/m3, the strength contribution tends to increase as the cement content increases. (3) The contributions of fly ash to strength at 91 and 364 days are 1.44 to 1.97 times as large as those at 28 days, respectively, by standard curing, but conversely decrease to 0.75 to 0.79 times those at 28 days by air curing.