Corroboration of Modelling Input data for AC Pavements

AbstractThe earliest study of asphaltic concrete pavement performance indicated that the deterioration process is a non-linear function of distresses that affect the AC fabric.Since AC pavements are non-homogeneous composites which are designed and often constructed to a number of different standards and requirements, the modelling of their progressive deterioration and future performance is a rather complex issue.There are a great number of pavement performance models used by road managing authorities, but do these models meet their expectations? To answer this question, a study was recently conducted into the maintenance practices adopted by local road authorities.In this study, prime consideration was given to the types of models that were adopted by these authorities and the quality of the output data generated by these models. Consequently, it was important to find out the quality of input data adopted for the older pavements which had some maintenance treatments applied and whether the model outcomes were satisfactory?The outcome of this study instigates the fact that the pavement modelling system does not perform satisfactorily on all levels of modelling and particularly on pavements that have very limited data in terms of structural capacities. Evaluation of pavement condition is carried out at certain intervals, usually between three to five years, and often the predicted model output does not match the actual road pavement conditions. In order to synchronise such a match, management uses some artificial ranking as they have no other means of measuring pavement structural strength and capacity. The available non-destructive testing methods are time consuming and often financially unaffordable for the whole road network. Destructive testing is not recommended and as it is also time consuming and costly. Therefore, they greatly rely on the old methods of pavement surface evaluations based on a visual assessment of the surface conditions. However, this type of evaluation is very restrictive in terms of accuracy and defects classification as well as establishing meaningful performance values that could be confidently used as modelling input data. In addition, this method does not provide any specific comparison between different pavements and this ultimately makes modelling limited.The aim of this publication is to establish a feasible evaluation method of a pavement deterioration process that would provide realistic numerical values relating to pavement strength and capacity. Consequently, this could be used as modelling input data.The ultimate solution to the existing problem would be the creation of a simple, easily accessible and inexpensive engineering instrument that would enable the measurement of pavement strength in-situ conditions