Optimum Design Development of Ductile Fiber-Reinforced Cementitious Composites Based on Fiber Bridging Characteristics

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H03802
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 23:Architecture, building engineering, and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Kanakubo Toshiyuki 筑波大学, システム情報系, 教授 (90261784)
• Co-Investigator(Kenkyū-buntansha): 菊田 貴恒 東北工業大学, 建築学部, 准教授 (20599055) ; 田嶋 和樹 日本大学, 理工学部, 教授 (60386000) ; 八十島 章 筑波大学, システム情報系, 准教授 (80437574)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 建築構造 / DFRCC / 架橋性能 / 架橋則 / 引抜性状 / 複合応力 / ひび割れ幅 / 有限要素解析

Outline of Final Research Achievements

Ductile fiber-reinforced cementitious composite (DFRCC) is expected to enhance the higher structural performance by discrete fibers mixed into cementitious matrix. The tensile performance of DFRCC is characterized by the bridging law (tensile stress - crack width relationship) that is built on the pullout behavior of individual fibers. The characteristics of the bridging law should be focused depending on the viewpoints of the structural performance of DFRCC members, in which the stress fields of DFRCC show complex states and are influenced by steel reinforcement. It is important that the characteristics of the bridging law such as stiffness, strength, tensile fracture energy, and also compressive fracture energy should be evaluated appropriately according to the purpose of the evaluation of the structural performance of DFRCC members.

Free Research Field

建築構造および材料

Academic Significance and Societal Importance of the Research Achievements

部材中の複雑な応力場における繊維の架橋性能を精確に評価してDFRCCの架橋則を構築し、部材の構造性能を評価することにより、DFRCCを用いる時に期待するひび割れ拡大抑制効果や部材耐力、靱性能の付加に対して、最適なDFRCC設計が可能となる。期待する効果に対して、架橋則の剛性に着目するのか、強度に着目するのか、破壊エネルギーに着目するのかの判断に資する成果が得られており、さらには、繊維の種類、径、長さなどの選別が可能となる。