Evaluation of Unbonded Jointed Concrete Overlays

Details

• Creators:
  Pérez, Jesús Castro ; Bhardwaj, Richa ; Roesler, Jeffery
• Corporate Creators:
  Illinois Center for Transportation
• Corporate Contributors:
  Illinois Department of Transportation. Bureau of Research ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Falling Weight Deflectometers Fibers Geotextiles Nondestructive Tests Overlays (Pavements) Pavement Interlayers Pavements Performance Rehabilitation (Maintenance) Roughness Testing

  More +
• Publication/ Report Number:
  FHWA-ICT-25-009
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Illinois
• Edition:
  Final Report 11/16/24–9/30/25
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  Concrete overlays for existing concrete and asphalt roads have been shown to be a viable rehabilitation or replacement option. This research project evaluated three unbonded concrete overlay (UBOL) projects in Illinois with high, medium, and very low truck volumes. The project’s goal was to assess each overlay’s performance including the influence of the interlayer. The project scope included distress surveys, evaluations of interlayer contact conditions through shear wave ultrasound tomography, assessments of structural response through falling weight deflectometer testing, profilometer testing, and core extractions. The findings from the UBOL performance study showed that nonwoven geotextile fabric (NWGF) can be an effective interlayer for concrete overlays under certain conditions. For thin UBOLs, even with macrofibers, steel tie bars should be used across the lane-shoulder joint to maintain shear transfer across a contraction joint or to limit construction joint opening. UBOLs with hot-mix asphalt (HMA) interlayers have historically provided good performance, which was seen in all three projects. For thinner UBOLs, slab geometry, interlayer type and transverse profile, and drainage must be considered in the overlay design. The I-72 eastbound section exhibited 3.8% longitudinal cracks (low severity) at transverse joints in the driving lane after 10 years, which has been linked to a combination of water in the joints, repeated truck loading, and debonding and low severity stripping of the HMA interlayer. For overlays with very few trucks (East Grand Road), the 6-inch slab and 11 feet by 12 feet slab size and the exclusion of dowel across transverse joints did not adversely impact UBOL performance.
• Format:
  PDF
• Funding:
  R27-SP74
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:de02e0b817e13aa0d3fbeb157b5c2aa1e2c4620751166f0456de95a8025d7e9897c59373868cabacf2423daa7fd4fce00d872ad5fec4252f05a4e09733da6da7
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/86907/dot_86907_DS1.pdf
• File Type:
  [PDF - 16.29 MB ]