2021 Fiscal Year Final Research Report

Theory for improving the strength of concrete using a large amount of by-product powder that does not have hydraulic lime

Research Project

PDF

Project/Area Number	18H01590
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 23010:Building structures and materials-related
Research Institution	Kyushu University
Principal Investigator	Koyama Tomoyuki 九州大学, 人間環境学研究院, 准教授 (50215430)
Co-Investigator(Kenkyū-buntansha)	湯淺昇日本大学, 生産工学部, 教授 (00230607) 陶山裕樹北九州市立大学, 国際環境工学部, 准教授 (20507876) 伊藤是清東海大学, 基盤工学部, 教授 (50380663) 白川敏夫九州産業大学, 建築都市工学部, 教授 (60623387)
Project Period (FY)	2018-04-01 – 2021-03-31
Keywords	副産粉体 / 資源循環 / コンクリート / 細孔構造 / 強度 / 粒子の平均間隔 / 平均空隙厚さ
Outline of Final Research Achievements	In the pore structure of hardened concrete, voids with a small diameter of about 50 nm or less do not adversely affect the strength, and therefore even when non-reactive by-product powder is used, when mixed by fixed cement content, Although the total amount of voids did not change as the amount of powder mixed increased, it was confirmed that the voids with small diameters increased relatively, so the strength improved and it could be effectively used as a by-product. In addition, in order to increase the proportion of small-diameter voids after curing and optimize the void structure, it was found that the average void spacing between particles before mixing should be minimized, and the optimum solution for improving the strength was found. Indicated. In the process of simulation, we found a more suitable average void thickness of particles as an evaluation index and further evaluated it.
Free Research Field	建築材料学
Academic Significance and Societal Importance of the Research Achievements	本方法によれば，単独で水と混合してもセメントのように硬化することのできない，反応性を有さない粉体を用いた場合でも，ベースとなるコンクリートの強度を向上させることができるので，例えば砕石を製造する際に副産する石粉や種々のフライアッシュなどの産業廃棄物の有効活用を，コンクリートの重要な要求性能である強度を向上させながら，可能にすることができる。またその際の，粉体構造を最適化する検討を行うことができる。