Performance Studies of Continuously Reinforced Concrete Pavement: Pavements Without Transverse Steel

About the report:

The status of studies of the three continuously reinforced pavement projects near Charlottesville is reported. Of particular interest in these studies are the effects of the elimination of transverse reinforcing steel, the changing characteristics of shrinkage cracking with age, and the end movements of anchor sections. While the studies are somewhat inconclusive at this early age of the pavements, the following tentative conclusions are offered: 1. Cracks show a definite trend to become both more closely spaced and wider during the first 2 to 3 years of a continuously reinforced pavement's life. There is some inconclusive evidence that the widening process stabilizes after this time period. 2. While crack spacing can be influenced by weather conditions during pavement placement, there is no apparent relationship between crack width and either crack spacing or placement weather. 3. As expected, cracks are significantly wider at the surface during winter (pavement shrinking) than during summer (pavement expanding). (Note - Earlier studies have shown that cracks which are easily seen and measured at the surface are invisible in the immediate vicinity of the reinforcing steel.) 4. End anchor movement is very modest during the first year and seems to decrease slightly with age. There is a pronounced seasonal effect which produces joint movements in excess of the capabilities of poured joint sealants. 5. The elimination of full width transverse steel has had no effect on pavement performance for the first 2 to 3 years. Acting upon a recommendation from these studies, the Department's pavement design engineer has instituted a requirement for the use of preformed compression seals in all expansion joints adjacent to the anchor slabs of continuously reinforced pavements.

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