Microstructural changes caused by carbonation of cement mortar

Research output: Contribution to journalArticle

Abstract

The change of specific surface area and pore size distribution due to carbonation of an ordinary Portland cement mortar is investigated. The adsorption of water vapor on noncarbonated and well-carbonated cement mortar is measured in order to evaluate the difference in specific surface area for the two samples using the BET theory. From the measured desorption the pore size distribution is calculated using the Kelvin formula. A sorption balance is used to measure the sorption characteristics for the two studied sample qualities. In this method dry and saturated air are mixed in desired proportion in a closed system. One of the benefits of the method is that the samples not are exposed to carbon dioxide during testing, i.e., undesired effects caused by carbonation on the sorption can be eliminated. The specific surface area for a noncarbonated sample was calculated, using the measured adsorption data, to be 8% higher than for the well-carbonated sample. The difference in pore size distributions was more marked than the difference in specific surface area for the two samples. The well-carbonated mortar had about twice as much volume attributed to small pores as the noncarbonated cement mortar.

Details

Authors
  • Björn Johannesson
  • Peter Utgenannt
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Materials Engineering

Keywords

  • Cement mortar, Carbonation, Sorption, Pore size, Distribution, BET equation
Original languageEnglish
Pages (from-to)925-931
JournalCement and Concrete Research
Volume31
Issue number6
StatePublished - 2001
Peer-reviewedYes

Related research output

Johannesson, B. 2000 Division of Building Materials, LTH, Lund University. 502 p.

Research output: ThesisDoctoral Thesis (compilation)

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