ARX linear modeling of hot mix asphalt compaction

The compaction of the asphalt layer is a fundamental operation in pavement construction but, at the same time, its control is very difficult. The consequences on costs, on execution time and on duration of the pavement are very relevant and, for that reason, we wanted to prepare a predictive model able to minimize the attempts, often unsuccessful, which the executor is forced to make in the early stages of the construction. Due to a very large number of variables, we could not control the phenomenon with any known physical models; so, for the purpose of this research paper, we preferred to make use of a so-called black-box linear model, calibrating it with an appropriate procedure of trials and errors. The results achieved with this model have made it possible to predict the value of the material density with a reliability of 88% that, for the number of involved variables, can be considered a satisfactory target. With this procedure and knowing the boundary conditions (characteristics of the roller and the material), it is possible to arrange the compaction very quickly, achieving a good compromise between layer density and execution times.