Development of guidelines for proper selection of finer graded aggregate base for Georgia pavements - phase I.

Details

• Creators:
  Kim, Sung-Hee ; Yang, Jidong
• Corporate Creators:
  Southern Polytechnic State University. Georgia Pavement and Traffic Research Center
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Fine aggregates
  • Base course (Pavements)
  • Pavement performance
  • Modulus of resilience
  • Pavement design
  • Alligator cracking
  • Screenings
  • Deformation
  • California bearing ratio
• Publication/ Report Number:
  FHWA-GA-10-1328
• Resource Type:
  Tech Report
• Geographical Coverage:
  Georgia
• Corporate Publisher:
  Georgia. Department of Transportation. Office of Research
• Abstract:
  In this study, the effects of No. 810 screening contents in GAB on pavement performance and GAB strength were investigated. One ; Group I (013C) source and three Group II sources (028C, 048C, and 158C) were selected and specimens were prepared for Proctor Test, ; CBR measurement, and morphological analysis. It showed that Proctor and CBR test results were influenced by morphological data and ; particle size distribution. It was found that replacing 25% of GAB with No. 810 screening materials decreased the density and strength of ; Group II assemblies while the opposite was true for Group I assemblies. Pavement performance with/without screening materials in GAB ; was simulated using the MEPDG software based on the measured CBR. As a result, replacing GAB with 25% of screening materials ; increased alligator cracking when Group II sources were used and decreased alligator cracking when Group I sources were used. ; Nevertheless, most of the aggregate assemblies with 25% of screening materials didn’t meet the GDOT’s GAB gradation requirements. ; Thus, further investigations including the permeability, plasticity index, resilient modulus, and life cycle cost analysis, may be needed ; prior to the adoption of screening materials in GAB. ; Additionally, a new methodology was developed to estimate the stress-strain relationship of unbound aggregate base using linear ; viscoelastic theory. Aggregate specimens prepared from two different sources were subjected to CBR test and relaxation modulus test ; thereafter. From the test data, the time-dependent stress due to a known strain rate was computed as a convolution integral of the strain. ; The computed stress-strain relationship was compared with ones from the resilient modulus test. The results indicate that the stress-strain ; relationships from the resilient modulus test and the convolution integral are quite comparable with nearly same slopes when horizontal ; stress is assumed as approximately 45% of vertical stress. Given this agreement, the proposed methodology could be used to assist state ; highway agencies to validate the resilient modulus test results for quality control and quality assurance of aggregate base materials for ; pavement design and construction.
  More +
• Format:
  PDF
• Funding:
  (RP 13-28)
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28654/dot_28654_DS1.pdf
• File Type:
  [PDF - 2.07 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:84196577a44e95106e077429b6ac64c274c452fddc8961fa1cf12569f601e15d