Epoxy Flooring and Cove Base Failure Investigation

A two-part epoxy flooring system had been selected for this research facility because the product was supposed to be flexible. Sometime after installation it became apparent that the system had failed. The floor and cove base were soft, brittle, and easily broken apart. Field reports also indicated the unexpected and undesirable presence of a liquid.

CTLGroup was engaged to study the epoxy material and determine the cause of the failure. The manufacturer's technical information sheets gave clear instructions on how to mix and proportion the two-component epoxy product. They specified that the material be mixed in a ratio of three parts resin to one part hardener, for at least five minutes.

In the laboratory, CTLGroup prepared the material for investigation, using a variety of mix ratios, mixing times, and moisture conditions. Investigators were able to recreate the failure in the laboratory and then analyze it to determine the product's modes of failure. The instrumentation used was an infrared spectrometer with an ATR accessory that allowed researchers to link their results with the failed epoxy samples in the field.

The results from this program determined that the field epoxy samples had not been mixed in the recommended proportions nor mixed for the recommended time. The product is supplied in containers of equal volume. Investigators consider it likely that the original floor installers mixed the floor system components at a 1:1 ratio instead of the specified 3:1 ratio. It also is possible that the material was not mixed for the specified time period, as even a properly proportioned mixture will not cure properly unless it is mixed correctly.