RESURFACING OF PLAIN JOINTED-CONCRETE PAVEMENTS

In 1975, the Georgia Department of Transportation placed a 1-mile concrete overlay test section on I-85 north of Atlanta, which has a high volume of truck traffic. The test area consists of 7.6-cm (3-in) continuously reinforced concrete (CRC), 11.4-cm (4.5-in) CRC, 15.2-cm (6-in) CRC, and a 15.2-cm (6-in) portland cement concrete (PCC) overlay. The primary objective was to determine the performance of various concrete overlay systems over a faulted jointed-concrete pavement. Some 16 asphaltic concrete overlay sections that had various thicknesses and treatments were placed adjacent to the PCC section in 1976. The performance obtained to date has indicated the importance of treatment of the existing pavement prior to placement of an overlay. Stabilization of moving slabs, replacement of fractured slabs, and patching and spall repair of the existing pavement are essential to the performance of the overlay. In addition, a level platform must be provided by grinding at the joints or by placement of a leveling course to prevent the overlay from being locked into the existing pavement by the faulted joints. Both 15.2-cm CRC and PCC sections, which have 4.6-cm (15-ft) joint spacing, are performing well at this time. The 15.2-cm thickness of concrete overlay should be considered minimum for resurfacing over concrete when there is heavy truck traffic. The results from the asphaltic concrete test sections indicate that the use of a waterproofing membrane or fabric with a 10.2-cm (4-in) asphaltic concrete overlay will reduce the occurrence and the severity of reflection cracking from the underlying joints. (Author)