Silane chemical protection of bridge decks (FHWA-OK-86-4) 2709

Abstract

This report describes the performance of chemical alkyltrialkoxysilane products and their ability to protect bridge structures from moisture, chloride ingr??ssion, and corrosion of reinforcing steel. As a result of the evaluation, the following recommendations are made:

The application of silane should be used to protect bridge structures from moisture and chloride ingression, and corrosion of reinforcing steel. The silane treatment should be used on both new and existing, bridge structures3in which the chloride content at the rebar depth has not exceeded 2.5 lbs/yd , or the corrosion potentials over the bridge deck area numerically do not exceed -350 millivolts. A dry concrete surfac?? is essential for successful applicatio2. An application rate of 125 ft /gal for horizontal surfaces and 175 ft /gal for vertical surfaces is recommended. After application, and the silane has penetrated, water should be applied to assure sufficient moisture for chemical reaction between the silane and concrete. ODOT field testing of the bridge decks selected for the silane performance evaluation should be continued through 1996 to determine the long term performance.