000 02248 am a22002173u 4500
042 _adc
100 1 0 _aHunt, Charles M.
_eauthor
_9301
700 1 0 _aTomes, Lewis A.
_eauthor
_9302
245 0 0 _aReaction of Hardened Portland Cement Paste With Carbon Dioxide
260 _b[Gaithersburg, MD] : U.S. Dept. of Commerce, National Institute of Standards and Technology,
_c1962.
500 _a/pmc/articles/PMC5324964/
520 _aThe effect of age, water-cement ratio, and evaporable-water content on the reaction of hardened cement paste with carbon dioxide was investigated, using small cylinders of cement paste. The rate and extent of the reaction are subject to manipulation by varying the evaporable water content of the paste. Pastes of different age and water-cement ratio tend to dry at different rates, and this difference exerts an important indirect effect on carbonation. Analysis of the specimens showed that less than one molecule of nonevaporable water was released for every molecule of carbon dioxide gained, except in paste of low water-cement ratio or at low levels of carbonation in other pastes. If calcium hydroxide were the only phase attacked, equimolecular CO(2)-H(2)O stoichiometry would be expected. The observed behavior does not rule out the possibility of some preferential attack on calcium hydroxide, but other phases can react while calcium hydroxide is still present. Water-cement ratio, particularly in very dense paste, may exert some effect on the comparative accessibility of different phases.
540 _a
540 _ahttps://creativecommons.org/publicdomain/zero/1.0/
540 _aThe Journal of Research of the National Bureau of Standards Section A is a publication of the U.S. Government. The papers are in the public domain and are not subject to copyright in the United States. Articles from J Res may contain photographs or illustrations copyrighted by other commercial organizations or individuals that may not be used without obtaining prior approval from the holder of the copyright.
546 _aen
690 _aArticle
_9303
655 7 _aText
_2local
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786 0 _nJ Res Natl Bur Stand A Phys Chem
856 4 1 _uhttp://dx.doi.org/10.6028/jres.066A.048
_zConnect to this object online.
999 _c105
_d105