Pavement Roughness on Expansive Clays

Details

• Creators:
  Velasco, Manuel O. ; Lytton, Robert L.
• Corporate Creators:
  Texas Transportation Institute. Texas A&M University
• Corporate Contributors:
  Texas State Department of Highways and Public Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  • Pavement design
  • Roughness
  • Expansive clays
  • Clay soils
  • Spacing
  • Wavelength
  • spectrum of crack spacings
  • amplitudes
• Publication/ Report Number:
  FHWA/TX- 81/ 3+284-2
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas ; United States
• Edition:
  Interim: September, 1979 - October, 1980
• Corporate Publisher:
  Texas Transportation Institute. Texas A&M University
• Description:
  The patterns of pavement roughness caused by expansive clays are due largely to the underlying patterns of cracks in the subgrade soil mass. The cracks will be closer together when the soil is more active and when the climatic wetting and drying cycles have greater influence. The cracking patterns in the soil and the consequent roughness patterns are not uniform but must be characterized as a spectrum of crack spacings and wavelengths with their corresponding amplitudes. Pavement roughness was measured by the GM Profilometer on 23 pavement sections in Texas. Two methods are used to obtain the amplitude versus wave length spectra that characterize the roughness patterns: the Fast Fourier Transform (FFT) method and the "bump" counter direct method. The two spectra are not the same nor are they expected to be. The FFT method is adopted for characterizing the roughness patterns because of its greater consistency. However, a correspondence is found between the two spectra. As a matter of convenience, the spectra are plotted as amplitude versus frequency, which is the number of wave lengths per unit length.
• Format:
  PDF
• Funding:
  2-8-80-284
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/85742/dot_85742_DS1.pdf
• File Type:
  [PDF - 5.51 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:d3b9535ba3f22892dac8e9e0aa6c8d3b430b1249271f4c0df7d982ad955253f9b128817c4b1b06fa3be785b555c761cc36adbbade07d56afd33116059121e83b