Articles

Axial Behavior of Carbon Nanofiber Enhanced UHPC Rectangular Columns

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Abstract

Advanced materials, such as ultra-high performance concrete (UHPC), are among the emerging technologies that can revolutionize our future structures with significantly improved strength and durability for a much longer service life compared to conventional concrete. Behind the excellent performance of UHPC stands its dense packing theory which excludes the usage of coarse aggregates and incorporates steel fibers in order to bridge the microcracks and provide high post-cracking strength and ductility. Emerging UHPC mixtures may also contain carbon nanofibers (CNFs) that further enhance the nanostructure of UHPC and its cracking behavior. Most of traditional as well as CNF-enhanced UHPC applications are still bridge field joints and other small-scale applications. Exploring the behavior and the design of robust UHPC mixtures with CNFs when used in full structural components will provide the understanding and the tools to expand the use of UHPC in large structural applications or full systems. Due to the lack of a comprehensive database on full-scale UHPC columns, especially CNF-enhanced UHPC columns, this research study provides a first look at the transverse reinforcement detailing effects on the structural behavior and deformation capacity of four full-scale UHPC rectangular columns tested at 4000-kip machine at UC Berkeley under axial loading. The paper focuses only on presenting and interpreting the behavior of the CNF-enhanced UHPC columns, but a small discussion of compressive behavior of CNF-enhanced UHPC cylinders with and without steel fibers is also provided to help better understand exclusive effects of CNFs when separated from conventional steel fibers.

Keywords: carbon nanofibers, full-scale testing, precast columns, axial loading

How to Cite: Cimesa, M. & Moustafa, M. A. (2023) “Axial Behavior of Carbon Nanofiber Enhanced UHPC Rectangular Columns”, International Interactive Symposium on Ultra-High Performance Concrete. 3(1). doi: https://doi.org/10.21838/uhpc.16687