Evaluation of Potential Long-Term Durability of Joints Cut with Early-Entry Saws on Rigid Pavements

Early-entry sawing is an attractive operation to expedite the construction of jointed concrete pavements; however, there are some concerns that early-entry sawing may compromise the pavement's long-term performance. The Illinois Department of Transportation initiated this study as an initial effort to investigate the durability of joints sawed by using early-entry sawing. Joint performance as a function of saw-cut depth and timing was also considered. The study was integrated into an active construction project along Illinois Route 59 in Plainfield. During construction, paving and sawing operations were observed and documented; of particular interest were the sawing operations, during which signs of surface scarring, joint raveling, and slab edge breakouts were recorded and the extent of sawing-related damage was subjectively assessed. In addition to general observations, climatic conditions were monitored, as was pavement temperature from time of paving onward. Ambient climate conditions, portland cement concrete mixture, and slab temperature data were used to perform a HIPERPAV analysis to assess the potential for early-age cracking. Compressive strength cylinders were also cast and tested at 3, 7, and 28 days. In addition, cores were retrieved from joints throughout the test section and a battery of durability tests—including petrographic analysis, freeze–thaw testing, and resistance to salt scaling—was conducted. Overall observations from the field construction and findings from the laboratory testing indicate that the use of early-entry sawing is viable and that joint durability is not compromised.