INFLUENCE OF WATER ON CARBONATION OF γ-C₂S AND CARBONATION BEHAVIOR OF HARDENED PASTE CONTAINING γ-C₂S

γ-C₂Sの炭酸化反応における水の影響とセメント水和物が共存したときの炭酸化挙動

This paper investigates the influence of water on carbonation of γ-C₂S (γ-2CaO・SiO₂) and carbonation behavior of γ-C₂S contained in hardened cement paste. From the result of accelerated carbonation (40℃, 50%RH, 20%CO₂), carbonation ratio of γ-C₂S without adding anything increased to 4% at age of 28 days. By the addition of water to γ-C₂S before accelerated carbonation, carbonation ratio of γ-C₂S reached 33%. Further, carbonation ratio of C₂S increased to 71% by continuous supply of water. It was found that carbonation ratio of γ-C₂S depended on the supply condition of water. On the other hand, carbonation ratio of γ-C₂S in hardened cement paste continued to increase without water supply under same accelerated carbonation conditions. In the surface portion, the carbonation ration of γ-C₂S contained in hardened cement paste reached 64% at age of 28 days and 75% at age of 91 days. This result suggested that, in case of hardened cement paste, the carbonation of γ-C₂S progressed effectively by water supply from micro-pore structure and carbonated cement hydrates. Based on the above result, the use of γ-C₂S as the cement admixture could be considered effective combination for carbonation progress of γ-C₂S.γ-2CaO・SiO₂（γ-C₂S）と、γ-C₂Sを混和したセメント硬化体の炭酸化挙動を比較検討した。γ-C₂Sを炭酸化する際に水を添加することで、28日における反応率は4％から33％に増加し、更に継続的に水を供給することで、71％まで増加した。一方、セメント硬化体中のγ-C₂Sは、水の供給を行っていないにも関わらず、継続的に炭酸化が進行し、反応率は促進91日で75％まで増加した。セメント硬化体の細孔中に存在する水や、セメント水和物が炭酸化して分解する際に放出される水によってγ-C₂Sの炭酸化が効果的に進行すると考察した。γ-C₂SをOPCと併用することが、γ-C₂Sの炭酸化を促進する効果的な組み合わせであることが明らかになった。

• Record URL:
  https://doi.org/10.14250/cement.68.186
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=INFLUENCE+OF+WATER+ON+CARBONATION+OF+%ce%b3-C%e2%1a%1aS+AND+CARBONATION+BEHAVIOR+OF+HARDENED+PASTE+CONTAINING+%ce%b3-C%e2%1a%1aS&author=M.+USHIRO&author=M.+SHOJI&author=M.+MORIOKA&author=I.+MARUYAMA&publication_year=2014
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09163182
• Authors:
  • USHIRO, Masataka
  • SHOJI, Makoto
  • MORIOKA, Minoru
  • MARUYAMA, Ippei
• Publication Date: 2014

Language

• English
• Japanese

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 186-191
• Serial:
  • Cement Science and Concrete Technology
  • Volume: 68
  • Issue Number: 1
  • Publisher: Japan Cement Association
  • ISSN: 0916-3182
  • EISSN: 2187-3313
  • Serial URL: https://www.jstage.jst.go.jp/browse/cement/-char/en
• Publication flags:

  Open Access (libre)

Subject/Index Terms

• TRT Terms: Admixtures; Carbonation; Cement paste; Hardness; Moisture content
• Subject Areas: Construction; Materials; Transportation (General); I32: Concrete; I50: Construction and Supervision of Construction;

Filing Info

• Accession Number: 01564582
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: May 26 2015 4:12PM