Study on utilization of activated fly ash as admixture for concrete

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K00602
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental engineering and reduction of environmental burden
• Research Institution: Nihon University
• Principal Investigator: UZAWA Masami 日本大学, 生産工学部, 教授 (80571299)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: セメント / コンクリート / フライアッシュ / 活性化 / ガラス質 / ポゾラン反応 / 未利用資源 / 下水汚泥焼却灰

Outline of Final Research Achievements

To determine the amount of glassy composition, crystalline components obtained by XRD-Rietvelt method was deducted from all components confirmed by X-ray Fluorescence analysis. The result shows relatively good straight–line correlativity in compressive strength and glassy composition converted into O/M ratio (oxygen/metal elements molar ratio) on mole-basis. When compared to the case with all composition obtained by XRF in horizontal axis, the determination coefficient was confirmed to be higher with only grassy composition recalculated to 100% in horizontal axis. In conclusion, it is necessary to focus attention on glassy composition for compressive strength estimation. The highest correlativity was obtained with O/(Si+Al+Fe+Ca+Mg-Na-K)) of which determination coefficient R2 of the correlativity was 0.729.

Free Research Field

材料科学

Academic Significance and Societal Importance of the Research Achievements

フライアッシュの化学成分と圧縮強度との関係をフライアッシュのガラス質の化学成分で説明でき、圧縮強度の２８日材齢を推定できることを明らかにした。また、活性化によってフライアッシュの強度を１０％高めることができた。このことは、フライアッシュのみならず、シリカ系のガラス質であれば共通の考え方であり、例えば下水汚泥スラグ微粉末やシラスなどの未利用資源にも展開が可能である。