Effect of Lithium Nitrate on the Alkali-Silica Reaction Gel
| Autor: | Paulo J.M. Monteiro, Nicole P. Hasparyk, José Fabian Schneider, Denise A. Silva |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Aqueous solution
genetic structures Lithium nitrate Potassium Inorganic chemistry Infrared spectroscopy chemistry.chemical_element Silicate chemistry.chemical_compound chemistry Sodium hydroxide Materials Chemistry Ceramics and Composites Alkali–silica reaction DIFRAÇÃO POR RAIOS X Alkali–aggregate reaction |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1551-2916 0002-7820 |
| DOI: | 10.1111/j.1551-2916.2008.02638.x |
| Popis: | Lithium nitrate has been used to prevent and to mediate the expansion caused by alkali-silica reaction (ASR). However, there is limited information on how it affects the existing reaction products caused by ASR. The aim of the present work is to determine the modifications caused by the LiNO3 treatment on the structure of the gel produced by ASR. ASR gel samples obtained from a concrete dam were exposed to an aqueous solution of lithium nitrate and sodium hydroxide with molar LiNO3/ NaOH=0.74, and the resulting products were analyzed by X-ray diffraction, infrared spectroscopy, and solid-state nuclear magnetic resonance of 29Si, 23Na, and 7Li. The treatment of the gel samples produces significant structural modifications in ASR products. A new amorphous silicate compound incorporating Li+ ions is formed, with an average silicate network that can be described as linear in contrast with the layered structure of the original gel. This elimination of the layered structure after the Li-based treatments may be related to the reduction of the tendency of the gel to expand. Also, several crystalline compounds containing potassium indicate the release of this species from the original ASR gel. |
| Databáze: | OpenAIRE |
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