Heat master
U.S. Steel Granite City Works – former National Steel in Granite City, IL, had major flooring issues with 1800 F coils on storage pads. Over several years they had tried standard concrete with conventional rebar to refractory material with 1” diameter Grade 304 stainless rebar on 12” centers (4” from the surface) with carbon steel fiber reinforcement. The thickness of the slab was 8”. The floor needed to hold up to both the coil temperatures as well as the outside conditions (moisture, heat and cyclic freezing).
Working closely with Granite City Works, Kerneos (formerly LaFarge) and Dr. Mark Patton /P.E.Ph.D (MEP Limited) it was determined that the rebar actually was expanding under the 1800 F coils. Kernoes recommended a low range calcium aluminate cement – Secar 41.
Fibercon replaced the rebar with 90 lbs./cubic yard of 3⁄4” Grade 304 stainless steel fibers to provide reinforcement from the top of the slab to the bottom. The stainless fibers would hold up against both the thermal cyclic shock of the coils and the outside conditions.
Core samples taken years later showing the stainless fibers to be shiny with no evidence of oxidation or corrosion. The pads themselves, although now older, appear in great condition even under these extreme conditions. The customer was extremely pleased with the solution to their never ending slab problem. A paper on this job, presented by Charles Alt of Kerneos back in 2005, is available upon request.