Rheology Control of Ultra-High-Performance Concrete Made with Different Fiber Contents
The study aims to improve flexural properties of ultra-high-performance concrete (UHPC) prepared with different steel fiber volumes by controlling the rheological properties of the suspending mortar. Welan gum and high-range water reducer were incorporated to control rheology. Optimum rheological properties led to enhanced fiber distribution. Fiber distribution coefficient was proposed and considered to characterize fiber dispersion and orientation. For UHPC with 1%, 2%, and 3% fiber volumes, the highest flexural performance was obtained with mortars having plastic viscosities of 36, 52, and 66 Pa·s, respectively. Beyond these values, further increase in viscosity resulted in greater air entrapment and lower mechanical properties. Prediction model for flexural strength that considers a correlation between fiber dispersion and flexural-to-tensile strength ratio of the UHPC was developed. Viscosity of UHPC mortar was shown to be a reliable indicator to determine flexural-to-tensile strength ratio, and hence predict flexural strength of UHPC.
L. Teng et al., "Rheology Control of Ultra-High-Performance Concrete Made with Different Fiber Contents," Cement and Concrete Research, vol. 138, Elsevier, Dec 2020.
The definitive version is available at https://doi.org/10.1016/j.cemconres.2020.106222
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Fiber distribution; Flexural performance; Plastic viscosity; Rheology; Steel fiber; UHPC
International Standard Serial Number (ISSN)
Article - Journal
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01 Dec 2020