ROLE OF HYDRATED SILICATE MONOMER IN C-S-H STRUCTURAL FORMATION MEASURED BY ²⁹Si MAS NMR AND ²H NMR

C-S-H構造形成における水和シリケートモノマーの役割─²⁹Si MAS NMRと²H NMRによる考察

This study show the role of Hydrated silicate monomer（HM）as the precursor for the Calcium Silicate Hydrate（C-S-H）that is the main component and directly affects physical properties of cementitious materials. Previous researches showed that the structure of C-S-H is not formed as soon as dissolution of cementitious minerals, dissolved sementitious minerals once form HM as the precursor for the C-S-H and they transpose to C-S-H gradually. The authors suggested a new method in which the amounts of HM were quantified from the difference of the dissolution and polymerization degrees used by ²⁹Si-MAS-NMR and X-Ray Diffraction（XRD）/Rietveld analysis. New method of HM and two instruments were used for solid-state ²⁹Si MAS NMR to measure amount of C-S-H and the mean length of silicate chain and the chemical environment of silicates such as neighbor ions to make clear the role of HM in formation of C-S-H. On the other hand, the solid-state ²H NMR was used to measure deuterium (²H or D）quadrupolar echo NMR specra, deuterium relaxation time T₁, rotational correlation time Ƭc and the ratio of high mobility water moleculars to low mobility water moleculars for white portland cement paste with D₂O.The results in NMR and XRD studies showed that curing conditions could change the HM formation in paste cured in sealed and water curing until 1 year；drying and heating treatments decreased the amount of HM and C-S-H formed in paste, in contrast they increased mean length of silicate anions chain in C-S-H；In drying condition, high relative humidity promote the consrult for of HM for formation of C-S-H, resulting in the increase of C-S-H本研究ではXRD/Rietveld法および ²⁹Si MAS-NMRを併用することによるintermediate phaseの定量法を用いて、セメント水和反応過程における水和シリケートモノマーの役割を検討した。水和シリケートモノマーは養生条件により変化し、水中養生においてカルシウムシリケート鉱物の溶解率40％から約30％に保持されることが示された。また、保持された水和シリケートモノマーは高湿度湿空養生や高温養生によりC-S-Hに遷移し、C-S-Hの平均鎖長が増加することが示された。²H NMRの測定によるセメント細孔中の準吸着水層の水層厚さの検討により、細孔内の乾燥により水和シリケートモノマーの遷移が促進される可能性が示唆された。

• Record URL:
  • https://doi.org/10.14250/cement.66.63
• Record URL:
  • https://www.jstage.jst.go.jp/article/cement/66/1/66_63/_pdf
• 
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=ROLE+OF+HYDRATED+SILICATE+MONOMER+IN+C-S-H+STRUCTURAL+FORMATION+MEASURED+BY+%c2%b2%e2%81%b9Si+MAS+NMR+AND+%c2%b2H+NMR&author=K.+KUROSAWA&author=D.+MINATO&author=T.+NAWA&author=R.+HATTORI&publication_year=2012
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09163182
• Authors:
  • KUROSAWA, Kazuto
  • MINATO, Daisuke
  • NAWA, Toyoharu
  • HATTORI, Renta
• Publication Date: 2012

Language

• English
• Japanese

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 63-70
• Serial:
  • Cement Science and Concrete Technology
  • Volume: 66
  • 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: Cement; Cement paste; Chemical properties; Curing agents; Drying; Hydration; Silicates
• Uncontrolled Terms: Calcium silicate hydrate
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01522869
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Apr 24 2014 11:44AM