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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Effect of Lithium Nitrate on the Alkali-Silica Reaction Gel

Texto completo
Autor(es):
Schneider, Jose F. [1] ; Hasparyk, Nicole P. [2] ; Silva, Denise A. [3] ; Monteiro, Paulo J. M. [4]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[2] Furnas Cent Eletr SA, DCT T, Lab Concreto, BR-74001970 Goiania, Go - Brazil
[3] WR Grace & Co, R&D GPC, Cambridge, MA 02140 - USA
[4] Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 - USA
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Journal of the American Ceramic Society; v. 91, n. 10, p. 3370-3374, OCT 2008.
Citações Web of Science: 15
Resumo

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 Si-29, Na-23, and Li-7. 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. (AU)

Processo FAPESP: 00/02805-6 - Estudo de estrutura de curto alcance em solidos inorganicos atraves da espectroscopia por ressonancia magnetica nuclear.
Beneficiário:José Fabián Schneider
Modalidade de apoio: Auxílio à Pesquisa - Regular