BRINGING CONCRETE BACK TO LIFE WITH CPR

This article describes the rehabilitation of a 5-mile stretch of I-57 south of Marion, Illinois. Pavement Specialists, Inc. (PSI), Napoleon, Ohio, the contractor for the $1.5 million job, first placed more than 700 sq yd of 2-in. and deeper patches. Using a California-type profilograph, PSI then plotted the surface contour at a scale of 1 in. to 25 ft horizontally and 1 in. to 1 in. vertically. A bump template placed on the plot indicated "must grind" bumps; a ruler with a blanking band covered deflections which did not require attention. To profile and texture the surface, PSI used two PC 5000 Cushion-Cut grinders. The first machine was used for spot grinding, while the second profiled and textured the pavement in a continuous pass. A third pass was made only when necessary because it had the potential to negate the texturing left by the first continuous pass. Further details are provided.