A Study of Geosynthetic Interlayers for Asphalt Overlays to Reduce Reflective Cracking

Due to temperature and/or moisture changes, freezing-thaw cycles, loss of subgrade support by erosion, and traffic loading, concrete pavements may develop different types of distresses during service life. Hot Mix Asphalt (HMA) overlays are commonly used to improve the serviceability of damaged concrete pavements. Some HMA overlays prematurely exhibit a cracking pattern similar to what existed in the old, underlying concrete pavement, which is often referred to as reflective cracking. The cracking in the overlays is often due to inability of the HMA overlays to endure tensile and shear strains. Tensile and shear strains develop because of movement of jointed or cracked slabs of underlying old pavements resulting in stress concentrations around pre-existing cracks. This movement is caused by a combination of traffic loading (differential deflections at cracks) and expansion and contraction of existing pavements due to change in temperature and/or moisture. When the induced tensile and shear stresses corresponding to the strains become higher than tensile and shear strengths of HMA, cracks develop in the overlay and propagate with the cycles of movement. Even though different techniques have been used to mitigate reflective cracking, they often do not yield satisfactory results and performance. Geosynthetics have been placed as interlayers between jointed or damaged concrete pavements and HMA overlays to mitigate reflective cracking. Laboratory and field data showed mixed performance results from success to failure. Past KTRAN research by the investigators found: (1) the shear failure could be avoid if the shear deformation of the HMA overlay was less than 6% of the overlay thickness and (2) the cracking could be avoided if the tensile strain in the HMA overlay was less than 0.6%. Proper geosynthetic interlayers should be selected to limit shear deformation and tensile strain of HMA overlays to tolerable values. Geosynthetic stiffness is one of the important parameters that affect the performance of HMA overlays and it will be investigated in this study. The objective of this research is to evaluate the effectiveness and benefits of different geosynthetic interlayers to mitigate reflective cracking on overlays through large box tests under cyclic loading.

Language

• English

Project

• Status: Active
• Funding: $88277
• Contract Numbers:

  K-TRAN: KU-22-4

  RE-0832-01

  C2191

• Sponsor Organizations:

  Kansas Department of Transportation

  Eisenhower State Office Building
  700 SW Harrison Street
  Topeka, KS  United States  66603-3754
• Performing Organizations:

  University of Kansas Center for Research, Incorporated

  2291 Irving Hill Drive, Campus West
  Lawrence, KS  United States  66045
• Principal Investigators:

  Parsons, Robert

  Han, Jie

• Start Date: 20210715
• Expected Completion Date: 20240714
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Geosynthetics; Hot mix asphalt; Overlays (Pavements); Pavement interlayers; Reflection cracking
• Subject Areas: Geotechnology; Highways; Maintenance and Preservation; Materials; Pavements;

Filing Info

• Accession Number: 01832314
• Record Type: Research project
• Source Agency: Kansas Department of Transportation
• Contract Numbers: K-TRAN: KU-22-4, RE-0832-01, C2191
• Files: RIP, STATEDOT
• Created Date: Jan 7 2022 1:17PM