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Title: Advances in understanding hydration of Portland cement

Progress in understanding hydration is summarized. Evidence supports the geochemistry dissolution theory as an explanation for the induction period, in preference to the inhibiting layer theory. The growth of C–S–H is the principal factor controlling the main heat evolution peak. Electron microscopy indicates that C–S–H “needles” grow from the surface of grains. At the peak, the surface is covered, but deceleration cannot be attributed to diffusion control. The shoulder peak comes from renewed reaction of C{sub 3}A after depletion of sulfate in solution, but release of sulfate absorbed on C–S–H means that ettringite continues to form. After several days space becomes the major factor controlling hydration. The use of new analytical technique is improving our knowledge of the action of superplasticizers and leading to the design of molecules for different applications. Atomistic modeling is becoming a topic of increasing interest. Recent publications in this area are reviewed.
Authors:
 [1] ;  [2] ;  [3]
  1. Laboratory of Construction Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 (Switzerland)
  2. Sika Technology AG, Zürich (Switzerland)
  3. Department of Civil and Environmental Engineering, University of California at Berkeley (United States)
Publication Date:
OSTI Identifier:
22475529
Resource Type:
Journal Article
Resource Relation:
Journal Name: Cement and Concrete Research; Journal Volume: 78; Journal Issue: Part A; Other Information: Copyright (c) 2015 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; ACCELERATION; CARBON SULFIDES; DIFFUSION; DISSOLUTION; ELECTRON MICROSCOPY; GEOCHEMISTRY; HYDRATION; HYDRIDES; INDUCTION; LAYERS; MOLECULES; PLASTICIZERS; PORTLAND CEMENT; REVIEWS; SULFATES; SURFACES