CA was retained to perform a forensic investigation to evaluate the distress observed in the cast-in-place concrete slab-on-grade at a 196,000 square foot distribution warehouse facility in Costa Rica. Thirty days after placement of the concrete, the owner of the facility observed signs of distress in the form of severe corrosion staining on the surface of the slab-on-grade warehouse floor which had been treated with a metallic aggregate floor hardener. The corrosion on the concrete surface had also affected the corrosion of the steel storage racks in the facility. CA’s investigation included the review and evaluation of construction related documents, assessment of the concreting practices, review of forensic engineering expert reports, a site visit and condition survey of the facility, temperature and humidity data collection, and concrete core sampling for petrographic examination. CA was able to determine the cause(s) of the distress through its investigation, which included construction defects, inadequate concreting practices during placement and curing, and provided the client with repair recommendations to ensure concrete durability of the warehouse.
