Introduction. The introduction to the paper describes the impact of critical temperatures and temperature loadings on the performance of the asphalt pavement layer and also on the entire flexible road pavement construction.
Problem statement. The issues of the paper concern significant aspects of the pavement temperature regimes prediction used in various systems of the flexible road pavement designing.
Purpose. The main goal of the paper is to review and compare the flexible road pavement designing approaches based on predicted temperatures of the asphalt pavement layer which may be reached under critical road pavement operating conditions.
Results. The application of the theory of thermal diffusion as the framework for the description of establishing the asphalt pavement layer temperature equilibrium was reviewed. As it is assumed, when the maximum asphalt pavement layer temperature is reached exists the equilibrium between outgoing and incoming flows such as outgoing and incoming longwave radiation, shortwave incoming radiation, convection losses and heat transfer. After wide investigations carried out by an SHR program, the maximum asphalt pavement layer temperatures calculated on that heat flows balance were proposed to be used in the flexible road pavement designing.
Also, the results of investigations carried out to develop the proposed theory of temperature equilibrium were analyzed and it was stated that under certain meteorological conditions the maximum asphalt pavement layer temperature will not be accompanied by the temperature equilibrium; the subsequent redistribution of heat flows may led to the values of temperature that significantly overcome the calculated maximum.
Further, some aspects of the prediction of temperature of the road pavement during the transitional winter/spring period performed via 3D FEM model constructed considering the thermal diffusion theory were reviewed. Similar approach to the modeling of the process of reflective cracking in an asphalt pavement overlay under temperature loads was recognized as an effective instrument to design the asphalt pavement repair strategy.
Conclusions. Systems for flexible road pavement designing implemented in the world-wide practice manage estimated values of the road pavement temperatures which can be reached under critical action of meteorological factors.
Considering the problem to be resolved, as the design input data the extreme values or gradients of the pavement temperatures shall be accepted.
The prediction of the asphalt pavement layer temperatures and also the road pavement temperature regimes calculation should be performed on the basic of the heat flows balance. The estimated maximum values of the asphalt pavement layer temperatures can be significantly overcame due to the peculiarities of the process of establishing of temperature equilibrium in the pavement.
The estimated critical values of the asphalt pavement layer temperatures allow the more effective modeling of the flexible road pavement response comparing with those performed with the mean values obtained through on-site observations.
