DESIGN CHARTS FOR THE DESIGN OF HMAC OVERLAYS ON PCC PAVEMENTS TO PREVENT REFLECTION CRACKING

The purpose of this study was to develop graphical procedures (design charts) for use in the design of Hot Mix Asphalt Concrete (HMAC) overlays on Portland Cement Concrete (PCC) pavements against reflection cracking, for implementation by the Texas State Department of Highways and Public Transportation for a range of specified local conditions. The final design procedure will be a hand solution method that will facilitate the overlay design process by substantially reducing the time and cost involved, particularly where computer facilities are difficult to access or estimating phases of the planning process do not permit a detailed analysis. Regression equations were developed for the prediction of overlay life, that is a direct function of the repetition of tensile stresses generated in the overlay by the horizontal movements of the concrete slab at the joints or cracks when temperature drops occur. The choice of equations was made following multiple linear regression analysis of a fractional factorial of simulated observations which were output from the ARKRC-2 program. The form of the equations was selected on considerations of the variation of the independent variable with respect to certain significant factors, fundamentally based on experience. A theoretical model developed at the Center for Transportation Research was used to predict limiting values of vertical slab movements at the joints or cracks when subjected to wheel load applications. Some mathematical relationships were developed and converted into a design chart to predict the limiting values of vertical movements. Those joints exceeding these limiting values should be subjected to some type of repair before overlay rehabilitation to minimize the potential for vertical movement and avoid premature reflection cracking. A recommended procedure for the use of the design charts is presented along with some typical application examples. (Author)

• Record URL:
  • https://library.ctr.utexas.edu/digitized/texasarchive/phase2/249-6-CTR.pdf
• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/85704
• Supplemental Notes:
  • Study conducted in cooperation Federal Highway Administration Research Study Title: Implementation of a Rigid Pavement Overlay Design System.
• Corporate Authors:

  University of Texas, Austin

  Center for Transportation Research, 3208 Red River Street
  Austin, TX  United States  78705

  Texas State Department of Highways & Public Transportation

  Transportation Planning Division, P.O. Box 5051
  Austin, TX  United States  78763

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Diaz, A M
  • McCullough, B F
• Publication Date: 1983-11

Media Info

• Media Type: Digital/other
• Pagination: 166 p.

Subject/Index Terms

• TRT Terms: Alignment; Asphalt concrete; Design methods; Equations; Forecasting; Hot mix asphalt; Joints; Motion; Pavement design; Pavement overlays; Portland pozzolan cement; Prevention; Reflection cracking; Regression analysis; Service life
• Uncontrolled Terms: Vertical alignment
• Old TRIS Terms: Joint
• Subject Areas: Data and Information Technology; Design; Highways; Maintenance and Preservation; Materials; Pavements; Security and Emergencies; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00393814
• Record Type: Publication
• Report/Paper Numbers: FHWA-TX-84-56+249-6 Intrm Rpt.
• Contract Numbers: Res. 3-8-79-249
• Files: NTL, TRIS, USDOT, STATEDOT
• Created Date: Jun 30 1985 12:00AM