The key findings for the 4-in. thickness and 20-ft joint spacing of BCOC projects are summarized as follows:
For 4-in. thickness of BCOCs: The PCI trend line remained above 60 during the first 15 years of service life The IRI trend line remained below 100 in/mi during the first 15 years of service life
For 20-ft joint spacing of BCOCs: The PCI trend line remained above 60 during the first 15 years of service life The IRI trend line remained below 100 in/mi during the first 15 years of service life
4.2.5. Performance of Unbonded Concrete on Concrete (UBCOC) Tables 15 and 16 summarize PCC slab thickness and transverse joint spacing data for UBCOC projects. Table 15. Slab thickness summary for UBCOCs PCC Slab Total Total Thickness Number of Number of (in.) Projects Data Points 4 3 7 5 19 54 6 66 263 7 20 82 8 12 52 9 4 23 10 1 2 Values with bold and italic numbers were selected for evaluating historical performance of concrete overlays.
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