Evaluation of fly ash performance on strength development based on material composition and its application to highly durable concrete

• Project/Area Number: 17K14708
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Civil engineering materials/Construction/Construction management
• Research Institution: Hiroshima University
• Principal Investigator: Ogawa Yuko 広島大学, 工学研究科, 助教 (30624564)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: フライアッシュ / 早強ポルトランドセメント / セメント有効係数 / 圧縮強度 / 置換率 / 蒸気養生 / 内部養生 / 養生条件 / セメント種類 / 細孔構造 / 土木材料

Outline of Final Research Achievements

The present study aimed to utilize fly ash for cementitious material in precast prestressed concrete, and the cementing efficiency factor of fly ash on the strength development of concrete using high-early-strength Portland cement (HPC) and the effect of curing condition on it were investigated. The results indicated that the k-values in HPC concrete were lower than that in ordinary Portland cement concrete. Additionally, it was found that the internal curing can solve the problem that the k-values under the steam curing condition cannot increase at later ages.

Academic Significance and Societal Importance of the Research Achievements

石炭火力発電の副産物であるフライアッシュは良質なポゾランであるが、養生環境や配合条件に反応が影響を受けること、また化学成分等品質が一定でないことから汎用されていない。本研究では、フライアッシュの強度発現性能を表すセメント有効係数（k値）について、生産性向上において着目されているプレキャストプレストレストコンクリートへの適用を念頭に、早強ポルトランドセメントをベースとして再整理した。さらに蒸気養生により低下する性能を内部養生により回復できる可能性を示し、これらの成果により高耐久コンクリートへのフライアッシュ利用の促進が期待される。

Research Products

• [Journal Article] Effects of porous ceramic roof tile waste aggregate on strength development and carbonation resistance of steam-cured fly ash concrete (2020)
  • Author(s): Ogawa Yuko、Bui Phuong Trinh、Kawai Kenji、Sato Ryoichi
  • Journal Title: Construction and Building Materials Volume: 236 Pages: 117462-117462
  • DOI: 10.1016/j.conbuildmat.2019.117462
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] An investigation on correlation between fly ash reaction and cementing efficiency factor for strength development of concrete (2019)
  • Author(s): Tan Phat Huynh、Yuki Miyoshi、小川由布子、河合研至
  • Journal Title: コンクリート工学年次論文集 Volume: 41 Pages: 245-250
  • Peer Reviewed
• [Presentation] 蒸気養生・内部養生を施したフライアッシュモルタルの強度発現性能に対するセメント有効係数の検討 (2019)
  • Author(s): 陰迫 良、三吉 勇輝、Huynh Tan Phat、小川 由布子、河合 研至
  • Organizer: 第74回土木学会全国大会年次学術講演会
• [Presentation] Effect of Curing Temperature on Degree of Fly Ash Reaction and Contribution of Fly Ash to Strength Development of Mortar (2019)
  • Author(s): Yuki Miyoshi, Tan Phat Huynh, Yuko Ogawa, Kenji Kawai
  • Organizer: The 3rd ACF Symposium on Assessment and Intervention of Existing Structures
  • Int'l Joint Research