The integrated model, developed for highway engineers involved in pavement design and management, provides a computer simulation of climatic effects on the behavior of pavement materials and subgrade conditions or characteristics over several years of operation of either asphaltic concrete or portland cement pavements. The results indicate that reasonable predictions of moisture and temperature conditions, frost penetration and heave, thaw weakening, and the accompanying effect on pavement moduli can be achieved. An overview of the model is provided and some typical results for two climatic regions in the united states are presented. The input variables were reduced to a minimum number and were assembled so that they were input in a free format on input user screens that appear sequentially in the course of data entry. Climatic data have been assembled and processed within the files of the program so that users are relieved of obtaining and entering large quantities of this information. At the same time, users can enter their own data if available. Carefully selecteddefault options that are representative of material properties of many typical highway pavement structures may be used, or a compendiumof alternative data for a variety of soils based on texture and index properties is provided in the user's manual. Deep ground temperatures and moisture conditions can be estimated from regional maps supplied in the manual. These features should make the integrated modelattractive to most highway design offices. The results of this simulation procedure will provide an important contribution to the complex process of assessing climatic effects on pavement design and management. This paper appears in transportation research record no. 1286, Design and evaluation of rigid and flexible pavements 1990.
Abstract