Studying the Early Cracking Behavior of Asphalt Concrete Base Course

In Iraq, there are some asphalt concrete mixtures suffer from appearing of cracking and deformation immediately after finishing the construction of a base course. In the flexible pavement, the pavement is considered to be degraded after opening to traffic by repeated traffic loading, climatic conditions, aging of asphalt mixture, etc. Crack plays a critical mode in pavement degradation. Several experimental studies have been carried out to gain a deeper understanding of the environment and weak construction monitor the action of pavement fractures. However, one downside of these previous studies was that the majority of them were carried out in a laboratory environment. A trial road section was studied after finishing base course construction by monitoring the early cracking. The major causes of appearing the early cracking have been investigated and debated. In this survey, three trial road sections with defined asphalt layers were considered. These trial sections were constructed with local materials brought from Nasrya refinery and Najaf quarry. On the basis of the findings obtained, two sections have deteriorated, while the third one was made as control for comparison purposes The observed early cracking could be attributed to the asphalt cement type and poor construction procedure occurring in an asphalt base layer as a result of low underlying sub-base course type and specifications.