WEATHERING STEEL

While CHLOR*RID has been used to remove corrosive salts from many steel and concrete structures, the soluble salt remover has now been specified by the NY DOT for use on a weathering steel bridge highly corroded by salts. The Kendricks Road Overpass in Rochester, NY is the site of a testing project involving CHLOR*RID, wet-blasting abrasives, and a specialty coating manufactured by Sumitomo of Japan called Weather-Act.

Prior to treatment a CHLOR*RID NACE Certified Coating Inspector, trained in the use of the CSN Salts kit, tested the chloride, sulfate, and nitrate levels of each beam. Three of the beams were wet abrasive blasted twice with water alone, and the other three where wet abrasive blasted and then pressure washed with 1% CHLOR*RID solution added to the wash water. After the cleaning was completed the same salts were tested for on each beam. The beams that had been wet abrasive blasted alone still showed an average of 50-70 μg/cm² of salt remaining, while the beams that had been cleaned with CHLOR*RID showed readings of 5 μg/cm² of salt or less.

Though the starting levels of contamination were not established, the results obtained after the surfaces were wet abrasive blasted twice exhibits that wet abrasive blasting with water alone does not provide adequate salt contamination reduction or removal.

What has been demonstrated here is that a simple pressure wash with the 1% CHLOR*RID solution after wet abrasive blasting did in fact reduce salt contamination in highly contaminated areas, not only adequately, but drastically.