BASIC STUDY ON ESTIMATION OF THE RHEOLOGICAL CONSTANTS OF FRESH CONCRETE

フレッシュコンクリートのレオロジー定数推定に関する基礎的研究

A flow constitution equation for expressing the flow properties is indispensable for understanding the flow properties of fresh concrete. The flow constitution equation for a cement-based material is generally expressed by using the Bingham model, where the rheological constants (yield value and plastic viscosity) are necessary. Paste, mortar, and concrete have been extensively investigated in studies on estimating the rheological constants from the mix proportion. However, no such studies have been conducted based on a single theory for all materials, from paste to concrete. In addition, there has been no study to theoretically estimate the shear strain rate dependence, the thixotropy (shearing time dependence), or the effect of hydration observed in the rheological characteristics of cement-based materials. Therefore, in the present study, the authors propose a method for estimating the rheological constants of paste, mortar, and concrete from the mix proportion on the basis of the viscosity equation assuming Roscoe's rule. By this method, the authors can consider the shear strain rate dependence, the thixotropy (shearing time dependence), and the effect of hydration. Furthermore, they examined the rheological constants determined by using the proposed viscosity equation. For cement paste and mortar, the validity of the rheological constants determined by using the proposed viscosity equation was confirmed by comparison with earlier experimental data. For concrete, the validity of the rheological constants determined by using the proposed viscosity equation was confirmed by comparison with experimental data through a simulated slump test using the finite element method.本研究では、ペーストからモルタルさらにコンクリートへと展開する新たな粘度式を提案した。そして、この粘度式を用いて、ペースト、モルタル、コンクリートのレオロジー定数を調合（配合）から推定する手法を示した。ここで、提案手法で求めたペーストとモルタルのレオロジー定数の有効性については、既往の実験結果との関係を比較・検討することで確認した。一方、コンクリートのレオロジー定数の有効性については、提案手法で求めたレオロジー定数を入力値として有限要素法でスランプシミュレーションを行い、実測結果と比較することで確認を行った。

• Record URL:
  • https://doi.org/10.14250/cement.66.661
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=BASIC+STUDY+ON+ESTIMATION+OF+THE+RHEOLOGICAL+CONSTANTS+OF+FRESH+CONCRETE&author=Y.+YAMADA&author=S.+AKAMINE&author=S.+IHA&author=S.+URANO&publication_year=2012
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09163182
• Authors:
  • YAMADA, Yoshitomo
  • AKAMINE, Shiori
  • IHA, Sakiko
  • URANO, Shinji
• Publication Date: 2012

Language

• English
• Japanese

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 661-668
• 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: Admixtures; Finite element method; Flow; Fresh concrete; Rheological properties; Shear strain; Simulation; Thixotropy; Viscosity
• Subject Areas: Construction; Highways; Materials; I32: Concrete; I50: Construction and Supervision of Construction;

Filing Info

• Accession Number: 01522929
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Apr 24 2014 11:45AM