More and more old industrial buildings are being repurposed for commercial and retail space. Many of these floors include steel fiber. Having polished two floors that had steel fibers by an expert team of applicators, here is what happened.
The first floors with steel fiber went very well and the fibers remained an integral part of the floor and looked great. Theses shiny silver flecks of steel where no problem....... until about 6-8 weeks later when the steel fibers that had been exposed, ground and polished began to rust. Then the staining became an issue and began to leach brown discoloration approximately 1" around the fiber. To fix the problem we had to cut back the floor, not too far just 200 resin back to 1500. Then we protected the floor with a two part epoxy designed to be burnished. The epoxy stopped the fiber rusting.
The second experience was not so kind. The old concrete was very soft the steel fibers would just tear out of the concrete as soon as the tooling hit them. So we figured out that if we densified the floor several times before we started grinding it would harden up the concrete. Sure enough after two days of densifing the floor got much harder and we began grinding the floor with little to know more fiber pop-puts. When we reach 400 resin we saw a bunch of scoping, the kind of spirals you sometime see with spiff coats of densifier. After a closer look these where not the regular scoping marks, rather deep rooted scratches. The few fibers that had popped-out where wrapped around the metal segments and had badly scratched the floor. No one had seen this and the scratches where not visible until the shine started to pop. So we ended up going back to 60 metal bond and re-cutting the floor. After every pass we had to tilt back the machine and look for fibers wrapped around the tooling. Eventually we had a scratch free floor and the client was happy.