Enhancement in self-compactability and stability in volume of entrained air in self-compacting concrete with high volume fly ash
Enhancement in self-compactability and stability in volume of entrained air in self-compacting concrete with high volume fly ash
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DOI：
10.1016/j.conbuildmat.2016.10.087
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发表时间：
2016-12-15
影响因子：
7.4
通讯作者：
Attachaiyawuth, Anuwat
中科院分区：
文献类型：
--
作者：
Puthipad, Nipat;Ouchi, Masahiro;Attachaiyawuth, Anuwat
研究了掺加气泡对大掺量粉煤灰新拌混凝土自密实性的影响。还分析了夹带气泡体积的稳定性。本文认为粉煤灰的保水性、球效应和掺加气泡是影响新拌混凝土自密实性的主要因素。结果表明，尽管水粉比（w/p）降低，但由于粉煤灰具有较高的承载作用，随着粉煤灰取代率（fa/p）的增加，自密实混凝土中的细集料含量（s/m）也可以增加。在一定类型的引气剂（AEA）的夹带气泡的滚珠轴承效应，也被发现，以进一步提高新拌混凝土与粉煤灰的自密实性。然而，夹带气泡体积的稳定性倾向于随着fa/p的增加而降低，这是由于产生了更大量的大夹带气泡。显然，球形的粉煤灰往往会导致在SCC中夹带的气泡的统一和逃逸。(C)2016爱思唯尔有限公司版权所有。
An experimental study on the effect of entrained air bubbles on the enhancement of self-compactability in fresh concrete with high volume fly ash was investigated. The stability in terms of volume of entrained air bubbles was also analysed. In this paper, lower water retention and ball-bearing effect of fly ash and entrained air bubbles were considered to affect the self-compactability of fresh concrete. The results showed that higher fine aggregate content in mortar (s/m) of SCC can be employed as replacement ratio of cement with fly ash (fa/p) increases owing to the higher ball-bearing effect of fly ash, in spite of reduction in water to powder ratio (w/p). The ball-bearing effect of entrained air bubbles, with certain type of air-entraining agent (AEA), was also found to further enhance the self-compactability of fresh concrete with fly ash. However, the stability in volume of entrained air bubbles tended to be reduced as fa/p increased, due to higher amount of large entrained air bubbles produced. Apparently, the spherical shape of fly ash tended to cause the unification and escape of entrained air bubbles in SCC. (C) 2016 Elsevier Ltd. All rights reserved.