THERMAL PAVEMENT CRACKING IN WEST TEXAS
Transverse cracking is a form of environmental deterioration that accounts for the expenditure of some twenty million dollars a year in maintenance in west Texas alone. This form of deterioration has not been predictable by previous mechanisms. A study of the environment in west Texas and installations of psychrometers beneath new construction show that freeze-thaw cycling is a major factor in west Texas, and acts primarily in the base course. The base course undergoes volumetric contraction upon freezing that is an order of magnitude larger than that of the asphaltic concrete. This contraction is related to the specific surface area of the clay mineral portion of the material with models being developed for predictive purposes. A theory of particle structure and reorientation is proposed from the data and from a theoretical interpretation of the Lennard-Jones Model for interparticle forces. This theory is verified in scanning electron micrographs of base course samples with and without the influence of freeze-thaw cycles. A computer model is developed which uses material properties to predict crack spacing caused by this contraction. The model uses actual climatic data to calculate the rate of crack growth and the change in crack spacing with time. An example is shown for Amarillo and Abilene to illustrate the use of the model.
- Prepared in cooperation with Texas State Dept. of Highways and Public Transportation, Austin.
Arlington, TX USA 76011
Texas State Department of Highways & Public TranspTransportation Planning Division, P.O. Box 5051
Austin, TX USA 78763
Washington, DC USA 20590
- Carpenter, S H
- Lytton, R L
- Publication Date: 1977-10
- Pagination: 251 p.
- TRT Terms: Asphalt concrete; Base course (Pavements); Clay minerals; Climate; Computer programs; Contraction; Electron micrographs; Forecasting; Fracture mechanics; Freezing; Melting; Pavement maintenance; Pavement performance; Pavements; Psychrometers; Simulation; Surfaces; Temperature gradients; Thaw; Thermal stresses; Transverse cracking
- Identifier Terms: FORTRAN (Computer program language)
- Uncontrolled Terms: Data; Freeze thaw cycles; Surface area
- Geographic Terms: Texas
- Old TRIS Terms: Periodic variations
- Subject Areas: Highways; Pavements;
- Accession Number: 00181389
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: FHWA-TX-77-18-4F Final Rpt., TTI-2-8-73-18-4F
- Files: NTIS, TRIS, USDOT, STATEDOT
- Created Date: Oct 12 1979 12:00AM