Evaluation of a Pyrament bridge deck overlay (FHWA-OK-96-12)

Abstract

The Oklahoma Department of Transportation (ODOT) has been using high density Portland cement (HDPC) overlays for more than twenty years to minimize spalls and delaminations in concrete. Since HDPC overlays were introduced, additives were incorporated into these mixtures to increase concrete strength and durabilty as well as decrease the time needed for curing. Pyrament, marketed and manufactured by Lonestar Industries, is a concrete comprised of 65% Portland Cement, 30% fly ash, and 5% trademark additive. In 1990, Pyrament concrete was used on a bridge reconstruction project. The Research,Development, and Technology Transfer (RD&T) of ODOT monitored the construction process and documented their findings. In order to assess the long term performance of Pyrament, RD&T has been evaluating this bridge deck since the completion of construction at regular intervals. Four tests were used to evaluate the condition of the two inch Pyrament overlay: visual, delamination, chloride ion content and half cell corrosion surveys. While there was widespread cracking, the chloride and half cell survys did not yield unusually high.chloride contamination or corrosion levels. Pyrament is no longer available for commercial use. This will be the final report on the long term performance of the Pyrament overlay system applied in Oklahoma County.