Effects of superplasticizers on the carbonation resistance of C₃S and C₃A hydration products

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• 作者：Tingshu He ; Chen Shi ; Guoxin Li ; Xuefeng Song
• 关键词：Carbonation ; Hydration ; Superplasticizer ; Crystal morphology ; Chemical bond
• 刊名：Construction and Building Materials
• 出版年：2012
• 出版时间：November, 2012
• 年：2012
• 卷：36
• 期：Complete
• 页码：954-959
• 全文大小：687 K

文摘

The effects of three superplasticizers, Polycarboxylic acid superplasticizer (PA), Naphthalene sulphonated superplasticizer (NS) and Aminosulfonic acid based superplasticizer (AS), on the carbonation and crystal morphology of tricalcium silicate (C₃S) and tricalcium aluminate (C₃A) hydration products were investigated. These three superplasticizers can improve the carbonation resistance of C₃S and C₃A hydrations. However, at the appropriate dosages, they have different performance in improving the anti-carbonation ability of C₃S and C₃A hydrations. The mechanism behind this phenomenon was investigated by analyzing the quantity and crystal morphology of calcium carbonate (CaCO₃), calcium hydroxide (CH) and ettringite using thermogravimetric analysis (TGA) and Stereoscan Electron Microscopic Photograph (SEM). The formations of calcium complex with superplasticizers are also estimated by means of X-ray photoelectron spectroscopy (XPS). These three superplasticizers can change the size, amount and orientation of hydrations. Thus, the anti-carbonation ability of the hydrations was improved.