THERMAL EXPANSION AND CONTRACTION CHARACTERISTICS-UTAH ASPHALT CONCRETES

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

• Supplemental Notes:
  • Vol 36, pp 673-702, 15 FIG, 7 TAB, 9 REF, 1 APP
• Authors:
  • Littlefield, G
• Conference:
  • Assoc Asphalt Paving Technol Proc
• Publication Date: 1967-2

Subject/Index Terms

• TRT Terms: Aggregate gradation; Aggregates; Asphalt concrete; Beams; Bituminous materials; Contraction; Cooling; Cracking; Densification; Heating (Structures); Surfaces; Tar; Temperature; Thermal expansion
• Uncontrolled Terms: Surface cracks
• Old TRIS Terms: Gradation
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00210725
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 2 1994 12:00AM