Unfortunately, far more highway bridges in the United States are "substandard" than are able to be repaired. A common sign of bridge deck wear is loss of skid resistance, which often becomes evident when water collects on the bridge deck. Bridge deck designers usually try to minimize water accumulation by establishing a cross slope with drainage channels and by deck surface texturing. A common method of texturing is transverse tining with a metal rake while concrete is still plastic. Although this method can produce grooves deep enough for a high-friction surface, the grooves are nonuniform and limited in depth.
A better method of getting maximum deck drainage is to saw grooves into the pavement transversely, or perpendicular to the direction of traffic, after concrete has cured. Bridge deck grooving is done by diamond saw blades that are ganged, or arranged at spaced intervals, on a shaft. Grooving can begin after deck concrete has cured to the minimum required compressive strength. Grooving is usually done perpendicular to the centerline to within about 1 foot of the gutter, curb, or parapet lines. Use a uniform groove spacing unless the deck is long. In that case, use random spacing. Slurry created by the water-cooled diamond blades should be continuously vacuumed from the pavement as grooving progresses.