The International Grooving & Grinding Association (IGGA) presents “Tips for Diamond Grinding Bridge Decks: Avoid These Common Mistakes Before Grinding the Bridge Surface” as an educational resource showing how contractors can avoid bridge joint damage. The document comes at a time when road owners are increasingly specifying diamond grinding to improve ride quality, friction and drainage capabilities of new bridge deck surfaces. Since diamond grinding involves removing a thin layer of concrete from the road surface, and because diamond grinding machines have long wheelbases and need to transition slowly into grade changes, the IGGA, in its capacity as a technical resource for the roadbuilding industry, is offering the guidance for accommodating the grinding process.
Expansion joints are placed at intervals along bridge decks and at the end of a bridge where it meets the roadway. The joints themselves, and bridge components under the joints, must be protected from damage during construction and surfacing operations. Failure to do so can result in financial penalties and repair costs for contractors performing the work. Grade control (i.e., creating even surfaces on either side of the joint), installing proper concrete thickness to accommodate removal of a layer during diamond grinding, and placing steel components at a proper depth within the concrete are examples of quality control measures that should be taken during construction. These recommendations, and others, are detailed in the tip sheet. Following the recommendations will allow contractors to reduce the risk of damage to vital bridge components—and to avoid penalties—while providing the driving public with smooth, safe and quiet bridge deck riding surfaces.
“With the increased focus on rideability and the desire to eliminate the ‘bump at the bridge,’ many contractors are turning to diamond grinding to deliver that smoothness. The guidance provided within the tip sheet will help them achieve their goals with confidence and minimum risk of damage to the structure,” says IGGA Executive Director John Roberts. —International Grooving & Grinding Association, West Coxsackie, N.Y.