Tack coat optimization for HMA overlays : accelerated pavement test report.

Details

• Creators:
  Al-Qadi, Imad L. ; Carpenter, Samuel H. ; Leng, Zhen ; Ozer, Hasan ; S. Trepanier, James
• Corporate Contributors:
  University of Illinois at Urbana-Champaign. Department of Civil and Environmental Engineering ; Illinois. Department of Transportation. Bureau of Materials and Physical Research
• Subject/TRT Terms:
  • Pavement design
  • Pavement components
  • Pavement cracking
  • Pavement layers
  • Overlays (Pavements)
  • Hot mix asphalt Pavements
• Publication/ Report Number:
  FHWA-ICT-09-035;ICT-09-035, UILU-ENG-2009-2006
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Edition:
  Final report
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  Interface bonding between hot-mix asphalt (HMA) overlays and Portland cement concrete (PCC) pavements is one ; of the most significant factors affecting overlay service life. This study was performed to quantify the effects of HMA type, ; tack coat type, tack coat application rate, and PCC surface texture on the interface bonding and overlay performance ; through laboratory testing, accelerated pavement testing (APT), and numerical modeling. This report presents the ; outcomes of the APT, as well as the numerical modeling of pavement interfaces. The results of the laboratory testing are ; covered in a companion report. ; The APT built on and validated previously completed laboratory tests where an HMA overlay was placed on top of ; an existing PCC pavement having various surface textures including smooth, transverse tined, longitudinal tined, and ; milled. In addition, zebra sections were included to evaluate the effect of non-uniform tack coat application. Asphalt ; emulsion SS-1hP and cutback asphalt RC-70 were applied at three residual application rates, 0.02, 0.04, and 0.09 gal/yd2 ; (0.09, 0.18, and 0.41 L/m2); asphalt binder PG64-22 was applied at 0.04 gal/yd2 (0.41 L/m2). Two HMA designs, standard ; binder mix and moisture sensitive binder mix, were used along with the three tack coats. Twenty-five pavement test ; sections were constructed and loaded with the Accelerated Transportation Loading ASsembly (ATLAS) at the centerline. ; The tensile strains at the bottom of HMA, to quantify potential interface slippage, were measured for selective sections, and ; primary HMA rutting was analyzed for all sections. The APT results validated laboratory determined optimum tack coat ; application rate, which provided the lowest interface strain and surface rutting in the field. Both PG64-22 and SS-1hP ; showed better rutting resistance than RC-70. Milled PCC surface provided lower rutting than transverse-tined and smooth ; surfaces. The field testing also showed that PCC cleaning methods play an important role in the HMA-PCC bonding. Higher ; rutting depth was measured in sections with uneven tack coat distribution compared to that with uniform tack coat ; distribution. Field testing results don’t show enough evidence to prove that using a moisture-sensitive mix will result in ; higher HMA surface rutting.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/16711/dot_16711_DS1.pdf
• File Type:
  [PDF - 3.66 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:daff294d50e096a0fa6dceb3dd5fb57867d85c19b3d2081a2ada676ebb3c2c8eeff284ef420f5888e68382da6c677ed3c9941c3a22378e6b149f8165dc1b1a29