IMPROVING FLEXURAL PERFORMANCE OF ULTRA HIGH PERFORMANCE CONCRETE BY RHEOLOGY CONTROL OF SUSPENDING MORTAR

Author(s): Kamal H. Khayat, Weina Meng, and Le Teng
Paper category: Proceedings
Book title: Proceedings of the 2nd International Conference on UHPC Materials and Structures (UHPC2018-China)
Editor(s): Caijun Shi and Baochun Chen
ISBN: 978-2-35158-219-0
e-ISBN: 978-2-35158-220-6
Publisher: RILEM Publications SARL
Publication year: 2018
Pages: 108
Total Pages: 1
Language : English

Abstract: This study develops a methodology to improve steel fiber distribution of ultra-high-
performance concrete (UHPC) by adjusting the rheological properties of the suspending
mortar before fiber addition. Rheology control can be achieved by changing the concentration
of the viscosity modifying admixture (VMA) of the self-consolidating UHPC. The plastic
viscosity was found to correlate well with the mini V-funnel flow time, which provides a
simple alternative to evaluate viscosity. Optimal plastic viscosities of suspending mortars for
UHPC mixtures proportioned with different fiber volumes are determined. Correlations
between the optimum plastic viscosity of the suspending mortar and the resulting steel fiber
distribution and flexural properties of the UHPC are established. The optimum plastic
viscosity range is found to lead to better uniformity of fiber distribution. This reflects better
fiber dispersion and fiber orientation that can lead to superior flexural performance of the
UHPC.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00