Analysis of micro-cracking of concrete and its applications

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01512
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22010:Civil engineering material, execution and construction management-related
• Research Institution: Hiroshima University
• Principal Investigator: Nakarai Kenichiro 広島大学, 先進理工系科学研究科(工), 教授 (10359656)
• Co-Investigator(Kenkyū-buntansha): 小川 由布子 広島大学, 先進理工系科学研究科(工), 助教 (30624564) ; 千々和 伸浩 東京工業大学, 環境・社会理工学院, 准教授 (80546242) ; 佐川 孝広 前橋工科大学, 工学部, 准教授 (90621045)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: コンクリート / 骨材 / 石灰石 / ひび割れ / せん断 / 膨張材

Outline of Final Research Achievements

This study focused on micro-cracking in concrete and examined its effects on the material and structural performance. At the material level, experimental results varying the curing conditions and the used materials such as limestone aggregate, expansion material, and blast furnace slag cement showed that the concrete material properties can be explained by the reaction rate of each mineral, the amounts of reacted water and hydrates. At the structural level, loading tests were conducted on RC beams, and it was shown that limestone aggregate concrete subjected to an initial high-temperature history could develop micro-cracks, which could resolve the reduction in shear strength.

Free Research Field

コンクリート工学

Academic Significance and Societal Importance of the Research Achievements

コンクリート内部に生じる微細ひび割れはコンクリート構造物の性能に影響を与える可能性があることを明らかにした．特に，収縮低減のために使用が増加している石灰石骨材はせん断耐力を低下させるが，微細ひび割れを意図的に導入することによってせん断耐力の低下を解消し，構造物の性能を向上させることができる可能性を示した．