COMBINED EFFECT OF TRAFFIC LOADS AND THERMAL GRADIENTS ON CONCRETE PAVEMENT DESIGN.

The purpose of this work is to study the behavior of concrete pavements under the simultaneous action of traffic and thermal gradients in concrete slabs. A new procedure for the structural design of concrete pavements in Spain is presented. A fatigue equation, taken from an adjustment of Tepfer's fatigue law and based on data on the behavior of several concrete pavements in Spain, is proposed. Analyses of loading stresses, thermal warping stresses, and simultaneous action stresses in slabs resting on a stratified semi-infinite solid were performed using a finite-element computer program. Empirical and theoretical equations for predicting the different values of thermal gradients and the frequency of their occurrence were established; these equations are based on Fourier's law and data obtained from observations in Spain. A computer program was developed to obtain new equivalence factors based on the results of the calculations.