EFFECT OF THE IONIC CONCENTRATION AND HYDRATION PRODUCTS ON PASTE FLUIDITY IMPROVEMENT WITH COMB-LIKE COPOLYMER FOR CEMENT PASTE

セメントの水和による液相イオンの変化と水和生成物が櫛形高分子の流動性改善効果に及ぼす影響

It this paper, influence of the ionic concentration of the liquid phase of cement paste and hydration products at early-age was studies. Fluidity of cement paste containing polycarboxylate-based dispersant(PC), consists of a comb-like copolymer with poly ethylene-oxide acts as a side chain. Three different types of cement(ordinary Portland cement (OPC), high performance concrete (HPC), white Portland cement (WPC))and three different types of dispersants of various conditions such as hydration periods, cement compositions and types of dosage in this study.  Result of experiments indicated that the influence of Ettringaite of hydration products on cement paste fluidity was not clear. Sulfate ions in liquid phase was different from every kinds of cement, but The influence of sulfate ions on cement paste fluidity was also not clear. So, Using adsorbed amount of PC, amount of Ettringite and concentration of sulfate ions, the authors performed multiple regression analysis.  The result of this analysis indicated that adsorbed amount of PC affect fluidity of cement paste. It was suggested that cement paste fluidity was decided adsorbed amount of PC.  Finally, it was concluded that the adsorption of PC acted that as the multi-layered structure not as the single-layered structure as previous reported from the viewpoint of hydrophobic aggregation of polymer.異なる3種のセメントを用いて、セメントペーストの液相イオン濃度と水和生成物がポリカルボン酸系分散剤(以下PC)の流動性改善効果に及ぼす影響について検討した。その結果、降伏値の高い領域では水和初期に生成するエトリンガイトが流動性を低下させる傾向が得られたが、低い領域では相関性は見られず、硫酸イオン濃度とPCの流動性改善効果との間には相関性は見られなかったため、それぞれの影響を統計的に考察するため、重回帰分析により検討を行ったところ、PCの吸着量が支配的に働いており、イオン濃度、水和生成物の影響は少ないことがわかった。また、PC同士が凝集し、セメント粒子表面に吸着していることが示唆された。

Language

  • English
  • Japanese

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01563174
  • Record Type: Publication
  • Source Agency: Japan Science and Technology Agency (JST)
  • Files: TRIS, JSTAGE
  • Created Date: Apr 23 2015 10:57AM