Effect of fly ash on tensile properties of ultra-high performance fiber reinforced cementitious composites (UHP-FRCC)

Abstract

This article presents and compare the tensile strain hardening behavior, compressive strength, energy absorption, and CO₂ emission of environmental friendly ultrahigh performance fiber reinforced cementitious composites (UHP-FRCC) containing various fly ash contents as partial replacement of premix cement (consisted of 82% low heat cement and 18% silica fume). Six series of UHP-FRCC are considered in this study. The first two series are control series while the rest four series contain 20, 30, 40, and 50% fly ash as partial replacement of premix cement. A small amount of nano silica (2 wt.%) is also added to compensate the low early age strength properties of the fly ash based UHP-FRCC. Results show that fly ash contents of 30–40% exhibited better compressive strength, tensile strain hardening behavior, and energy absorption than the other fly ash contents in the UHP-FRCC. The UHP-FRCC containing 40% fly ash shows about 12, 14, 10, and 22% reduction in compressive strength, ultimate tensile strength, ultimate tensile strain, and energy absorption capacities, respectively, than the control, while its CO₂ emission is about 35% lower than the control. The reported properties of UHP-FRCC containing 40% fly ash are still higher than other reported UHP-FRCC containing other SCMs as well as many reported UHP-FRCC containing no SCMs except the silica fume.

Keywords:

• class F fly ash
• nano silica
• silica fume
• UHP-FRCC
• strain hardening
• energy absorption
• compressive strength

Acknowledgment

Authors acknowledge to Japan society for the promotion of science for awarding invitation research fellowship to the first author in 2014.

Disclosure statement

No potential conflict of interest was reported by the authors.