ANALYSIS AND VERIFICATION OF THERMAL-GRADIENT EFFECTS ON CONCRETE PAVEMENT

An experimental and analytical study was conducted to develop an effective method for determining realistic thermal-load induced stresses in concrete pavements. Temperatures throughout the concrete slabs were measured over an extended time period. Resulting critical stresses were then analytically derived following the procedure developed in this study. To verify these analytical stresses, load-induced strains and deflections were recorded at numerous locations on the test slab at various time periods, using the falling weight deflectometer as a loading device. The findings confirmed the importance and the need to account for the thermal gradient in the design and analysis of concrete pavements. The temperature data indicated that the temperature distributions were mostly nonlinear and can be represented fairly well by a quadratic equation. In addition, theoretical analysis of the induced stresses suggests the consideration of the total temperature distribution throughout the concrete slab depth rather than the temperature differential between the extreme slab fibers. Finally, the measured strains were close to the computed ones, showing the appropriateness of the analytical model used in this study.