Title: Deflection Hardening and Workability of Hybrid Fiber Composites

Author(s): Joshua D. Blunt and Claudia P. Ostertag

Publication: Materials Journal

Volume: 106

Issue: 3

Appears on pages(s): 265-272

Keywords: deflection hardening; fiber-reinforced material; flexural stiffness; performance characteristics; workability.

DOI: 10.14359/56551

Date: 5/1/2009

Abstract:
A deflection-hardening hybrid fiber-reinforced concrete (HyFRC) mixture design was developed based on a predetermined performance criterion. Various hybrid and nonhybrid fiber combinations were also investigated. Consistency measurements and flexural tests demonstrated that a hybrid fiber combination used with a concrete-based matrix can enhance material flowability and cohesiveness while maintaining flexural strength. HyFRC beam elements were cast and tested in four-point bending, and the results were compared against the flexural performance of plain concrete control beams with and without conventional steel reinforcement. HyFRC with reinforcing bar at reinforcing ratios of 0.3% can enhance post-crack flexural stiffness while maintaining lower yield strengths compared to a reinforced plain concrete element with a reinforcing ratio of 1.1%.