Fiber-Bridging Constitutive Law of Engineered Cementitious Composites

• Published in: Journal of Advanced Concrete Technology Vol. 6; no. 1; pp. 181 - 193
• Main Authors: Yang, En-Hua, Wang, Shuxin, Yang, Yingzi, Li, Victor C.
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Concrete Institute 01.01.2008; Japan Science and Technology Agency
• Subjects: Cement constituents; Cracks; Durability; Fibers; Law; Limit states; Mathematical models; Strain hardening
• ISSN: 1346-8014; 1347-3913; 1347-3913
• DOI: 10.3151/jact.6.181

This paper is on modeling and measuring fiber-bridging constitutive law of Engineered Cementitious Composites (ECC), a high performance fiber-reinforced cementitious composite featuring high tensile ductility. Fiber-bridging constitutive law plays an important role in the multiple cracking behavior of ECC. Therefore, proper control of fiber-bridging behavior through tailoring material microstructure is the key to successfully designing tensile strain-hardening ECC. In this paper, an analytical fiber-bridging model of ECC which connects material constituent parameters and composite properties, built on a previous simplified version, was proposed. To improve accuracy of crack opening prediction, new mechanisms of fiber/matrix interactions, specifically fiber two-way debonding and pull-out, matrix micro-spalling, and Cook-Gordon effects were included. This revised model was compared with experimental measurement of fiber-bridging behavior and the validity of the model was confirmed. It is expected that this model will greatly improve ECC design technology in terms of steady-state crack width control, key for structural long-term durability, and in terms of composite tensile properties important for structural safety at ultimate limit state.