TEMPERATURE DEPENDENCY OF DYNAMIC DEFLECTION MEASUREMENTS ON ASPHALT PAVEMENTS

Research efforts were directed toward analyzing the effect of relatively high service temperatures on the deflection parameters and establishing correction factors for more accurate estimation of asphalt pavement performance. For this purpose, a continuous program of Dynaflect measurements extending over 2 years was carried out on full-depth asphalt pavement test sections in Kuwait. Measured deflection basins were correlated with those predicted by applying elastic layer theory. Cores were taken for laboratory characterization of the pavement materials under simulative conditions. Both measured and predicted values indicated a reduction in the miximum Dynaflect deflection parameter between the load wheels at pavement temperatures exceeding 40 deg C. The reduction in measured deflection values increases with the decrease of both asphalt layer thickness and its stiffness. Within the temperature range for normal Dynaflect measurements, correction have developed for the evaluation of alastic modulus values of both asphalt layers and subgrade. These correction factors have been related to a standard pavement temperature for the condition of no temperature gradient within the pavement. Corrected measured values were found to be reflecting the changes in the deflection behavior of the road pavement during high service temperatures.