Laboratory evaluation of influence of operational tolerance (acceptance criterion) on performance of hot-mix asphalt concrete.

Details

• Creators:
  Vazquez, Christian G. ; Aguiar-Moya, Jose P. ; Smit, Andre de F. ; Prozzi, Jorge A.
• Corporate Creators:
  University of Texas at Austin. Center for Transportation Research
• Corporate Contributors:
  Texas. Dept. of Transportation
• Subject/TRT Terms:
  • Hot mix asphalt
  • Asphalt
  • Aggregate gradation
  • Density
  • Fault tolerance
  • Hot-mix asphalt concrete (HMAC)
  • Asphalt content
  • Gradation
  • Density
  • Operational tolerances
  More +
• Publication/ Report Number:
  FHWA/TX-11/0-6045-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Corporate Publisher:
  University of Texas at Austin. Center for Transportation Research
• Abstract:
  The performance of flexible pavements relies heavily on the final quality of the hot-mix asphalt concrete (HMAC) as it ; is produced and placed in the field. To account for production and construction variability while ensuring the quality of the ; HMAC, TxDOT has established a set of relevant operational tolerances, which are incorporated into the 2004 Standard ; Specifications for Construction and Maintenance of Highways, Streets and Bridges. In particular, Items 340/341, 342, 344, ; and 346 provide acceptance criteria for all HMA mixes used by the Department. The operational tolerances for a series of key ; control variables that affect performance are given as a guideline in QC/QA practices. However, the relationship between ; these tolerance levels and mixture performance is not well known. This research project will establish this relationship: how ; do the operational tolerances affect the expected performance of the HMAC? Once this relationship is quantified, ; recommendations will be developed that indicate, if necessary, how the current tolerances should be modified. ; The objective of the study was to determine the effects of variability in key mix design factors, such as asphalt content, ; gradation, and density, on the laboratory performance of different hot-mix asphalt samples that were mixed and compacted in ; the laboratory. Variability was kept within specified limits by the allowable operational tolerances, and performance was ; addressed through the evaluation of the results obtained from volumetric properties and laboratory tests, such as flexural ; fatigue test, Hamburg wheel-tracking test, and overlay tester. A series of statistical analyses were conducted to develop ; relationships between the key mix design factors and the observed laboratory performances of each type of mixture. From the ; analysis, the effects of the main variables on the results of the performance tests used in this study were found. ; Finally, a statistically-based sensitivity analysis was conducted to reveal the relationship between different tolerance ; levels and mixture performance for the individual mixtures types. This research facilitates, for both TxDOT personnel and ; contractors, the evaluation of asphalt mixture performance under different tolerance levels, which will be performance-based ; and supported by a rigorous and sound statistical analysis.
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• Format:
  PDF
• Funding:
  0-6045
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18668/dot_18668_DS1.pdf
• File Type:
  [PDF - 1.16 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:ddda3c70b5cf1d1f008c25b869e9baef95f474ee300c95487d594412335e11fd