From gyratory data to field compacity – a numeric model

The compaction of an asphalt mixture is a dynamic process influenced by various factors, including mixture properties, cooling rate and timing of the roller passes. At times, the target compacity may not be reached or achieved inefficiently. Laboratory compaction tests, done at constant temperature and energy level, often fall short in predicting real field compaction. To bridge the gap between laboratory and field compaction, a numerical model designated as Field Compacity Model (FCM) is proposed. The FCM is based on gyratory data and integrates field specificities by accounting for the mixture's cooling curve, roller types, number of passes and their timing. The objective of the FCM is to identify potential risks of field compaction issues at an early stage in an accessible and efficient manner. Following an initial verification stage, the model was used to estimate field compacity in three practical case studies, where it showed good predictive performance.