Pozzolanic reactivity of zeolitic rocks from two different Cuban deposits:: Characterization of reaction products
Pozzolanic reactivity of zeolitic rocks from two different Cuban deposits:: Characterization of reaction products
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DOI：
10.1016/j.clay.2005.12.001
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发表时间：
2006-04-01
影响因子：
5.6
通讯作者：
Gener, M
中科院分区：
文献类型：
--
作者：
Martínez-Ramírez, S;Blanco-Varela, MT;Gener, M
火山火山灰是富含 SiO2 和 Al2O3 的玻璃质或结晶性差的材料，与水泥水化过程中生成的硅酸钙石反应，生成水合硅酸钙和铝酸盐，具有低溶解度和良好的胶凝性能（火山灰反应）。本研究的目的是分析氢氧化钙与古巴发现的两种天然部分结晶火山灰之间的反应，表征产生的 C-S-H 凝胶并确定之间的关系为此目的进行的 XRD 和 FTIR 分析结果包括，衍射图上的沸石（片沸石和八面沸石）峰随着反应时间的推移而逐渐下降，沸石的红外吸收带发生变化，以及指示 CSH 凝胶形成的新谱带的出现。尽管两种火山灰在 90 天后固定的 Ca 量为类似地，洛斯刚果材料的反应速度更快。卡罗莱纳州样品中形成的凝胶的成分中含有 Al，其中含有 Q(3) (1Al) 和 Q2 (1Al) 单元，其含量随时间而增加。洛斯刚果样品中 Fe 的存在妨碍了对形成的凝胶的分析，尽管可以从 Al-27 MAS NMR 数据推断其成分中存在 Al。热力学数据表明两种情况下均形成了C-S-H凝胶。 (C) 2005 Elsevier B.V. 保留所有权利。
Volcanic pozzolans are vitreous or poorly crystallized materials rich in SiO2 and Al2O3 that react with the portlandite generated during cement hydration to yield hydrated calcium silicates and aluminates with low solubility and good cementitious properties (pozzolanic reaction).The purpose of the present study was to analyze the reaction between calcium hydroxide and two natural, partially crystalline pozzolans found in Cuba, characterize the C-S-H gels produced and determine the relationship between pozzolan composition and structure and its capacity to fix calcium.The findings of the XRD and FTIR analyses conducted with this aim included a gradual decline of the zeolite (heulandite and faujasite) peaks on the diffractograms with reaction time, and changes in the IR absorption bands attributed to the zeolites, along with the appearance of new bands indicative of the formation of the CSH gel.Although the amount of Ca fixed by the two pozzolans after 90 days was similar, the reaction rate was faster in the Los Congos material. The gel forming in the Carolinas sample had Al in its composition, with Q(3) (1Al) and Q2 (1Al) units whose content increased with time.The presence of Fe in the Los Congos sample hampered the analysis of the gel formed, although the presence of Al in its composition could be inferred from the Al-27 MAS NMR data. The thermodynamic data showed that C-S-H gel was formed in both cases. (C) 2005 Elsevier B.V. All rights reserved.