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Title: Alteration of alkali reactive aggregates autoclaved in different alkali solutions and application to alkali-aggregate reaction in concrete

Surface alteration of typical aggregates with alkali-silica reactivity and alkali-carbonate reactivity, i.e. Spratt limestone (SL) and Pittsburg dolomitic limestone (PL), were studied by XRD and SEM/EDS after autoclaving in KOH, NaOH and LiOH solutions at 150 deg. C for 150 h. The results indicate that: (1) NaOH shows the strongest attack on both ASR and ACR aggregates, the weakest attack is with LiOH. For both aggregates autoclaved in different alkali media, the crystalline degree, morphology and distribution of products are quite different. More crystalline products are formed on rock surfaces in KOH than that in NaOH solution, while almost no amorphous product is formed in LiOH solution; (2) in addition to dedolomitization of PL in KOH, NaOH and LiOH solutions, cryptocrystalline quartz in PL involves in reaction with alkaline solution and forms typical alkali-silica product in NaOH and KOH solutions, but forms lithium silicate (Li{sub 2}SiO{sub 3}) in LiOH solution; (3) in addition to massive alkali-silica product formed in SL autoclaved in different alkaline solutions, a small amount of dolomite existing in SL may simultaneously dedolomitize and possibly contribute to expansion; (4) it is promising to use the duplex effect of LiOH on ASR and ACR to distinguish the alkali-silicamore » reactivity and alkali-carbonate reactivity of aggregate when both ASR and ACR might coexist.« less
Authors:
 [1] ;  [2] ;  [2] ;  [2] ;  [3]
  1. College of Materials Science and Engineering, Nanjing University of Technology, 5 New Model Road, Nanjing, Jiangsu, 210009 (China) and ICON/CANMET, Natural Resources Canada, 405 Rochester Street, Ottawa, ON, K1A 0G1 (Canada). E-mail: duyoulu@njut.edu.cn
  2. College of Materials Science and Engineering, Nanjing University of Technology, 5 New Model Road, Nanjing, Jiangsu, 210009 (China)
  3. ICON/CANMET, Natural Resources Canada, 405 Rochester Street, Ottawa, ON, K1A 0G1 (Canada)
Publication Date:
OSTI Identifier:
20871560
Resource Type:
Journal Article
Resource Relation:
Journal Name: Cement and Concrete Research; Journal Volume: 36; Journal Issue: 6; Other Information: DOI: 10.1016/j.cemconres.2006.01.008; PII: S0008-8846(06)00011-1; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARBONATES; CONCRETES; DOLOMITE; EXPANSION; LIMESTONE; LITHIUM HYDROXIDES; LITHIUM SILICATES; MICROSTRUCTURE; MORPHOLOGY; POTASSIUM HYDROXIDES; QUARTZ; REACTIVITY; SCANNING ELECTRON MICROSCOPY; SILICA; SODIUM HYDROXIDES; SOLUTIONS; TEMPERATURE RANGE 0400-1000 K; X-RAY DIFFRACTION