STUDIES ON THE SULFATE RESISTANCE OF CEMENT-BASED MATERIAL MIXED THE Ca-Mg-Si-BASED MATERIALS AND WATER CURING AND AUTOCLAVE CURING

Ca-Mg-Si系材料を混和し、オートクレーブ養生および水中養生したセメント系材料の硫酸塩抵抗性に関する基礎的研究

Nowadays, in the Middle East region where sulfate is abundantly found in soil, the sulfate attack on concrete structures is one of the serious problems. On the other hand, in japan, the utilization of industrial-by-product for cementitious material is required from the viewpoint of environmental protection and forming recycling society. Ca-Mg-Si based materials can be generated from industrial-by-products such as Steelmaking slag. However, Ca-Mg-Si based materials are not being used yet. Consequently, the using of Ca-Mg-Si based materials is contributes to the reduction of the environmental burdens and economical load. Therefore, the purpose of this study was to establish the material design of the high durability of cementitious material using Ca-Mg-Si based materials. In this study, the sulfate resistance of the hardened bodies formed by autoclave curing or underwater curing, using cement, silica powder, and Ca-Mg-Si based materials, such as Akermanite and Merwinite, was examined. Then, porosity, length change ratio from sulfate immersion test was measured. And identification of product materials inside hardened body based on x-ray diffraction (XRD) was done.As the experimental results, in the cases of 40％ Ca-Mg-Si based materials substitution ratio with underwater curing, the length change ratios had the values that lower than 0.1％. Furthermore, in the cases of specimens formed by Ca-Mg-Si based materials with autoclave curing, the length change ratios were quite lower values that less than 0.07％. This is due to the generation of tobermorite at low substitution ratio and Si structure like tobermorite at high substitution ratio.本研究では、普通ポルトランドセメント（OPC）とケイ石微粉末および、製鋼スラグ等の産業副産物に含有するCa-Mg-Si系材料を用い、水中養生およびオートクレーブ（AC）養生を行った供試体の硫酸塩抵抗性を、反応生成物や結晶構造と関連付けて考察し、耐硫酸塩性に優れた高耐久コンクリートの材料設計の提案を目的とし検討を行った。その結果、水中養生では、OPCをCa-Mg-Si系材料により40％置換することで硫酸塩抵抗性の向上が認められた。AC養生では、Ca-Mg-Si系材料の混和のみによって更に硫酸塩抵抗性が向上した。これは、Ca-Mg-Si系材料の混和とAC養生によって供試体中に化学的安定性を有するトバモライトや、トバモライトと同様のSi構造を有する化合物が生成したためと考察した。

• Record URL:
  https://doi.org/10.14250/cement.67.38
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=STUDIES+ON+THE+SULFATE+RESISTANCE+OF+CEMENT-BASED+MATERIAL+MIXED+THE+Ca-Mg-Si-BASED+MATERIALS+AND+WATER+CURING+AND+AUTOCLAVE+CURING&author=I.+TAKAHASHI&author=T.+SAITO&author=T.+SAEKI&author=M.+KIKUCHI&publication_year=2013
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09163182
• Authors:
  • TAKAHASHI, Issei
  • SAITO, Tsuyoshi
  • SAEKI, Tatsuhiko
  • KIKUCHI, Michio
• Publication Date: 2013

Language

• English
• Japanese

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 38-45
• Serial:
  • Cement Science and Concrete Technology
  • Volume: 67
  • 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: Autoclave curing; Calcium; Concrete curing; Magnesium; Silicates; Sulfate resisting cement; Tobermorite
• Uncontrolled Terms: Sulfate resistance
• Subject Areas: Highways; Materials; Pavements; I30: Materials;

Filing Info

• Accession Number: 01562583
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Apr 30 2015 9:24AM