Strength and microstructural characteristics of chemically activated fly ash-cement systems
Strength and microstructural characteristics of chemically activated fly ash-cement systems
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DOI：
10.1016/s0008-8846(02)00973-0
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发表时间：
2003-03-01
影响因子：
11.4
通讯作者：
Lee, KM
中科院分区：
文献类型：
--
作者：
Lee, CY;Lee, HK;Lee, KM
粉煤灰作为水泥替代材料的使用增加了混凝土的长期强度和耐久性。尽管有这些巨大的好处，但由于粉煤灰混凝土的早期强度低，粉煤灰的使用受到限制。为了解决这个问题，许多研究已经进行了加速粉煤灰的火山灰性质。本文研究了含有Na 2SO 4、K2 SO 4和三乙醇胺三种激发剂的粉煤灰-水泥体系的强度和微观结构特征，以加速粉煤灰砂浆的早期强度。热重分析结果表明，活化剂不仅能减少或维持Ca（OH）2的生成量，而且能增加早期钙矾石的生成。X射线衍射，扫描电子显微镜，压汞测孔法也证实，在早期固化阶段的粉煤灰水泥浆含有活化剂，形成大量的钙矾石，导致在从0.01到5 μ m范围内的孔径减小。研究结果支持了掺加少量激发剂是提高粉煤灰混凝土早期抗压强度的可行方案的假设。(C)2002爱思唯尔科技有限公司版权所有。
The use of fly ash as a cement replacement material increases the long-term strength and durability of concrete. Despite these great benefits, the use of fly ash is limited due to the low early strength of fly ash concrete. To eliminate this problem, many studies have been conducted on accelerating the pozzolanic properties of fly ash. The study reported below investigated the strength and microstructural characteristics of fly ash-cement systems containing three kinds of activators-Na2SO4, K2SO4, and triethanolamine-to accelerate the early strength of fly ash mortars. Through the use of thermal gravity analysis, it was demonstrated that the activators not only decreased or maintained the amount of Ca(OH)(2) products, but also increased the production of ettringite at early ages. X-ray diffraction, scanning electron microcopy, and mercury intrusion porosimetry also confirmed that in the early curing stages of fly ash-cement pastes containing activators, large amounts of ettringite were formed, resulting in a reduction in the pore size ranging from 0.01 to 5 mum. The research results support the supposition that the addition of small amounts of activators is a viable solution for increasing the early-age compressive strength of fly ash concrete. (C) 2002 Elsevier Science Ltd. All rights reserved.