Development of A Non-Linear Regression-Based Model for Prediction of Depth Temperature of Asphalt LayersUsing LTPP Data – Case Study: Ohio, USA

Depth temperature of asphalt layers is one of the important factors in the analysis, design and rehabilitation process of flexible pavements. The predictive models as an alternative to field and laboratory measurements of this factor, are rapid and simple methods to determine the depth temperature of asphalt layers. It should be noted that these models are based on the limited field and laboratory data, therefore, there is a need for developing new models for prediction of the depth temperature of asphalt layers in different traffic and climatic conditions. The main purpose of this study is to develop a model for predicting the depth temperature of asphalt layers based on climatic data. The modeling method used in this study is a stepwise non-linear regression model that predicts the depth temperature of asphalt layers based on the other variables, including the desired depth from the pavement surface, air temperature, average speed and direction of the wind, minimum air humidity and solar radiation. Data was extracted from the Long-Term Pavement Performance (LTPP) database. As a case study, data points collected from pavements in Ohio, USA, has been used for modeling. Furthermore, the developed model is well validated using data from Montana, USA. Performance evaluation and validation of the developed model showed very good correlation between predicted and measured values. Results show the ability of the developed model in predicting the depth temperature of asphalt layers based on existing climatic data with very good prediction accuracy (R2 (LOE) =0.95) and very low bias.