50% Fiber Savings
Use up to 50% less steel fiber to achieve the same UHPC performance as competing fibers
The striated surface of HiPer fibers enables a great increase in UHPC material performance compared to competing fibers. In a study from the University of Michigan (https://onlinepubs.trb.org/onlinepubs/IDEA/FinalReports/Highway/NCHRP235.pdf), HiPer steel fibers at a dosage of 1% by volume showed comparable strain hardening capacity to competing steel fibers at 2% by dosage (see Table below).
Comparison between Type X HiPer Steel Fibers and Competing Fibers
Fiber | Fiber volume fraction | First cracking strain | First cracking Stress | Elastic modulus | Localization strain | Tensile strength |
Vf (%) | εcr (in./in.) | fcr (ksi) | Ec (ksi) | εt (in./in.) | ft (ksi) | |
Type X | 1.0 | 0.00018 | 1.09 | 5956 | 0.0023 | 1.18 |
1.5 | 0.00019 | 1.23 | 6648 | 0.0030 | 1.35 | |
2.0 | 0.00017 | 1.52 | 8786 | 0.0042 | 1.79 | |
Smooth | 1.0 | 0.00018 | 1.02 | 5679 | 0.0016 | 1.09 |
1.5 | 0.00020 | 1.19 | 5872 | 0.0022 | 1.28 | |
2.0 | 0.00020 | 1.48 | 7081 | 0.0026 | 1.66 |
Other rigorous research studies have consistently shown that UHPC reinforced with HiPer steel fibers dramatically outperforms that reinforced with competing steel fibers. The bridge below is the first bridge in the US (and likely the world) to use UHPC reinforced with steel fibers at a dosage of only 1.5% by volume – versus 2-3.25% commonly used.
Gratiot road bridge over the Moak Drain. Constructed 2023 in St. Clair Couty, Michigan is the first bridge in the US to use steel fiber at a dosage of 1.5% by volume. Competing steel fibers are typically used at a dosage of 2% to 3.25%.
HiPer Fiber could have saved $2.4 M in fiber cost on Delaware Memorial Bridge. The project used 2 million pounds of smooth steel fiber at 430 lbs/cubic yard (https://www.delawareonline.com/story/news/2019/04/30/dont-forget-tolls-go-up-delaware-memorial-bridge-tomorrow/3625235002/). Hiper Fiber could have been used at the rate of 200 lb cubic yard.