Steel Fiber-Matrix Interfacial Bond in Ultra-High Performance Concrete: A Review

Ultra-high performance concrete (UHPC) is a relatively new cementitious concrete composite with signif-icant application potential in infrastructure construction because of its excellent mechanical strength and durability. The steel fiber-matrix interfacial bond is the main factor that governs other mechanical prop-erties of UHPC, including tensile, flexural, and compressive strengths and failure mode (fracture behav-ior). This paper presents a comprehensive review on the research progress of fiber-matrix bond behaviors of UHPC by discussing and comparing a range of fiber pullout testing methods and analytical models. The parameters of the fiber-matrix bond, including the geometry and orientation of fibers, sur-face treatment, and composition and strength of the matrix, are identified and discussed in detail. Lastly, recommendations for future research related to UHPC strengthening methods and testing details are pro-vided based on recent progress. (c) 2022 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).