The U.S. Army cold regions research and engineering laboratory (crrel) is developing a mechanistic pavement design method for use inseasonal frost areas by the corps of engineers and the air force. The mechanistic method will employ results from a series of five computer programs that compute soil and pavement moisture and temperature conditions (frost1), resilient modulus and poisson's ratio (transform), stresses and strains in the pavement system (julea and nelapav), and cumulative damage (cumdam). The model has been calibrated for the properties of six soils. Five fatigue equations, three based on horizontal strain at the bottom of the asphalt layer and two basedon vertical strain at the top of the subgrade, are used to determine the cumulative damage for two-, three-, and four-layer pavement sections at springfield, missouri, and rochester, minnesota. Although all of the equations predicted failure during the design life for each pavement section modeled, significant jumps occurred during the spring, indicating that the thaw period is crucial in the fatigue life of a pavement. This paper appears in transportation research record no. 1286, Design and evaluation of rigid and flexible pavements 1990.
Abstract