COMPARISON OF SHRINKAGE BEHAVIORS BETWEEN MORTARS CURED INTERNALLY WITH SUPERABSORBENT POLYMER AND SATURATED LIGHTWEIGHT AGGREGATE

超吸水性ポリマーおよび軽量骨材を用いたモルタルの収縮挙動の比較

Internal curing is an effective way to reduce risks of early-age cracking due to autogenous shrinkage in high strength concrete. Adequacy of several porous materials for internal water reservoirs has been investigated. Lightweight aggregate（LWA）and superabsorbent polymer （SAP）particles are considered as the most appropriate materials for the internal curing. However, these two materials are quite different in absorbing capacity and particle sizes. Futhermore, spatial distribution of them are also quite different each other. Internal water of LWA is present within the aggregate particles while SAP is dispersed as a constituent within the entire cement paste matrix. Then location of SAP particles was strictly controlled by the presence of rigid aggregate particles. Therefore, effectiveness as the internal water reservoir could be different between both materials even if the same amounts of internal water were provided. In this study, mortar specimens containing the same amount of internal water were produced using LWA and SAP. Autogenous and drying shrinkage behaviors were experimentally compared between the two systems of internal curing. SAP was more effective in reducing autogenous shrinkage than LWA. LWA is more preferable in terms of reducing drying shrinkage. These differences in shrinkage behavior may be explained from difference in time to release initial water and the amount of water present in the cement paste matrix. Rapid release of internal water from SAP can result in the increase in drying shrinkage.超吸水性ポリマー（SAP）および軽量骨材（LWA）を用いて等量の内部貯水を保持させたモルタルの収縮挙動を比較し、これらの内部貯水粒子の空間分布の相違が、内部養生に及ぼす影響について実験的に検討した。軽量骨材粒子の方が互いに近接した配置になるが、個々の粒子のもつ内部水量が少なく、また、放水は遅いと考えられ、このため内部水を若材齢にて放出するSAP粒子よりも自己収縮抑制効果は小さくなると考えられる。しかし、その一方にて、SAPによる初期の放水はマトリックス中の水量を増大させて乾燥収縮を大きくするが、軽量骨材を用いると、その放水特性のために乾燥収縮はSAPを用いたものよりも小さくなる。

• Record URL:
  • https://doi.org/10.14250/cement.67.171
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=COMPARISON+OF+SHRINKAGE+BEHAVIORS+BETWEEN+MORTARS+CURED+INTERNALLY+WITH+SUPERABSORBENT+POLYMER+AND+SATURATED+LIGHTWEIGHT+AGGREGATE&author=H.+KUWABARA&author=S.+IGARASHI&author=K.+YOKOTA&publication_year=2013
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09163182
• Authors:
  • KUWABARA, Hiroshi
  • IGARASHI, Shin-ichi
  • YOKOTA, Koichiro
• Publication Date: 2013

Language

• English
• Japanese

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 171-178
• 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: Absorbents; Concrete curing; Lightweight aggregates; Mortar; Polymers; Shrinkage
• Uncontrolled Terms: Internal curing
• Subject Areas: Highways; Materials; I33: Other Materials used in Pavement Layers; I36: Aggregates;

Filing Info

• Accession Number: 01561954
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Apr 28 2015 3:08PM