Effect of cement C3A content, temperature and storage medium on thaumasite formation in carbonated mortars
Effect of cement C3A content, temperature and storage medium on thaumasite formation in carbonated mortars
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DOI：
10.1016/j.cemconres.2005.11.010
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发表时间：
2006-04-01
影响因子：
11.4
通讯作者：
Martínez-Ramirez, S
中科院分区：
文献类型：
--
作者：
Blanco-Varela, MT;Aguilera, J;Martínez-Ramirez, S
本研究的目的是确定水泥C(3)A含量、温度和浸泡介质(水、石膏和硫酸镁溶液)的组成对水泥砂浆中硅铝石形成速率的影响。本研究的砂浆棱柱是由两种不同的水泥制成的，一种是低含量的，另一种是高含量的，分别添加或不添加石膏和/或碳酸钙。经过水化、固化和碳化后，棱镜部分浸入蒸馏水中，并在0至5摄氏度的温度下储存长达5年。一些棱镜在室温下浸泡在2%(w/w)的石膏溶液或1.4%(w/w)的硫酸镁溶液中。在不同的年龄采集了样品，并进行了矿物学和显微结构特征分析。观察到一些被测试的样品在环境和较冷的温度下都发生了膨胀，这一过程与硅铝石或硅铝石和钙矾石的固溶体的形成过程相一致。水泥CA含量与膨胀过程中劣化产物的组成之间存在相关性：低C(3)A水泥配制的砂浆中形成硅铝石，而高C(3)A水泥配制的砂浆中钙铝石和钙矾石形成混合晶体或固溶体。(C)2005爱思唯尔有限公司。保留所有权利。
The purpose of this study is to determine the effect of cement C(3)A content, temperature and composition of the immersion medium (water, gypsum and magnesium sulphate solution) on the rate of thaumasite formation in cement mortars. It also aims to ascertain how the CA content influences the composition of the salt formed.The mortar prisms for this study were made with two different cements, one with low and the other with high Al2O3 content, with or without gypsum and/or calcium carbonate. After hydration, curing and carbonation, the prisms were partially immersed in distilled water and stored at temperatures ranging from 0 to 5 degrees C for up to 5 years. Some of the prisms were immersed in a 2% (w/w) gypsum solution or in 1.4% (w/w) magnesium sulphate solution at ambient temperature. Samples were taken at different ages and mineralogical and micro-structurally charactetised. Some of the specimens tested were observed to expand, in a process concurring with the formation of thaumasite or a solid solution of thaumasite and ettringite, at both ambient and cooler temperatures. A correlation was found between cement CA content and the composition of the deterioration product involved in the expansive process: thaumasite forms in mortars made with low C(3)A cement, whereas mixed crystals or solid solutions of thaumasite and ettringite form in mortars made with high C(3)A content cement. (c) 2005 Elsevier Ltd. All rights reserved.