Bridges

High performance paint coatings of modern days require the prepared surface to have Sa 21/2 (very thorough blast cleaning) or higher class of finish. Dry abrasive blasting easily meets this requirement resulting in adequate bonding of the paint coating to the substrate, thus achieving durability of the elements. This method of surface preparation is very fast and effective in preparing a large surface. However, the method is not cost-effective for use on small areas on site due to the associated peripheral work.Advanced power tools are now available to provide nearly the same level of surface preparation as obtained with dry abrasive blasting without the need to have the peripheral work associated with the latter. One of such power tools, Bristle Blaster, was used for preparing the welded areas on the steel girders of a recently constructed bridge in New South Wales. The trial, carried out in collaboration with the contractor to validate its use, indicates the tool has the potential to become a preferred method for small areas for bridges in the future.This paper briefly describes the methods commonly used for surface preparation, the trial procedure and the outcome achieved using this tool on the welded areas of the steel girders.