130% Stronger
Increase in fiber bond strength with surrounding UHPC matrix compared to competing fibers
The striations on the surface of our steel fibers are optimized to provide the best possible interaction between the fiber and the surrounding steel matrix. The technology was developed based on extensive experimental and computational research. The experimental work was primarily done using the pullout test, where a single fiber or group of fibers are pullout out of a UHPC specimen. The force required to do is measured and plotted against the pullout slip. We have conducted hundreds of such tests during the development stage.
The figure below shows that the striated fibers achieve 130% more pullout resistance than a competing smooth steel fiber that slips out easily from the matrix. The increase of 130% was carefully tuned by balancing the risk for fiber breakage (and hence a complete drop in ductility) and easy pullout (and hence a weak reinforcement effect).