ABSTRACT
ABSTRACT: The Kansas Department of Transportation (KDOT) instrumented four perpetual pavement sections with stress and strain gauges to investigate the suitability of perpetual pavement concept. Pavement response measurements under known vehicle load at three different speeds were performed on seven occasions. Falling-Weight Deflectometer (FWD) first-sensor (center) deflections were normalized and corrected to 20 °C temperature based on measured mid-depth pavement temperature. FWD deflection data were also used to back-calculate layer moduli. Dynamic modulus tests were done in the laboratory. The results show no clear trend of an increase or a decrease in stress, strain, center deflection, and backcalculated AC layer modulus with time at the early age. There is a decrease in stress and strain with an increase in traffic speed. A change in speed from 64 km/h to 32 km/h has a higher impact on the stress and strain than a change in speed from 96 km/h to 64 km/h for thicker sections and vice versa for thinner section. The assumed endurance limit of 70 microstrain was exceeded in the thinnest section. The effect of high temperature on stress and strain is more pronounced at the lower traffic speed and on the thinner section. Laboratory dynamic modulus is higher than the back-calculated modulus.
