A design system for minimizing asphalt concrete thermal cracking has been developed. Asphalt concrete "thermal cracking" occurs in the form of transverse, longitudinal, and/or block cracking. Major factors causing these cracks include (1) very low temperatures resulting in tensile stress that exceeds mixture tensile strength, and (2) daily temperature cycling resulting in repeated tensile stresses and strains that cause asphalt concrete thermal fatigue. Therefore, thermal cracking occurs not only in cold climates, but also in climates where there is a large daily tempaerature range and high solar radiation. Although the intitial occurrence of the cracks has little effect on pavement performance, routing and filling the cracks becomes a maintenance problem. As water infiltrates the cracks, swelling or consolidation of pavement or subgrade layers may occur causing considerable roughness. Spalling of the cracks in airfields can cause foreign object damage (F.O.D.) to aircraft engines. As severe as the problem may seem, thermal cracking can be minimized or completely eliminated for new asphalt pavements through the use of a rational mixture design system. Such a system has been developed and verified and is presented in this paper. The verification showed that the system is a reliable tool for selecting the most suitable asphalt grade, asphalt supplier, and mixture design for minimizing thermal cracking. The inputs to the system are the environmental conditions where the pavement is to be constructed, asphalt grade, asphalt concrete mixture characteristics, and variability associated with the inputs. The output of the system is the amount of thermal cracking as function of age, expressed in sq ft/100 sq ft or ft/100 sq ft. A procedure is also descibed to assess the effect of different amounts of thermal cracking on pavement structural integrity and surface operational condition. /Author/

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 920-932

Subject/Index Terms

Filing Info

  • Accession Number: 00170258
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Mar 29 1978 12:00AM