Study of the causes and remedies of premature surface cracking of asphalt pavements

Abstract

Over the past 120 years, the asphalt industry has evolved to become a multi billiondolar business achieving significant technological advances and providing better and effective road infrastructure. However, it has also been experiencing a number of problems. One such major problem is a perception, and arguably a reality, that asphalt pavements are not being designed and constructed to meet its long term objective or being cost effective. At the same time, there is a growing backlog of needs due to unexpected early asphalt road deterioration. This deterioration includes several problems such as early cracking, rutting, moisture damage and surface roughness. The result is that at the turn of the century, despite major efforts, better economic and technical solutions for these problems, more work remains to be achieved. On a positive note, however, the pressure to address these problems and develop better solutions has led to a number of key initiatives which are shaping the asphalt industry today. These initiatives include the Strategic Highway Research Program (SHRP), which deals in part with the characterization of asphalt materials and their performance under a wide range of in-service conditions. Also the use of advanced materials such as non-metallic polymeric grid and/or polymer modified asphalt binders to reinforce asphalt layers and/or improve their tensile and shear strengths and the introduction by many agencies of end-result specifications; some agencies are even going to long-term performance based specifications have contributed to an improvement in the pavement performance. There is no doubt that most of these developments, if not all have significant technical and economic potential. One of the unresolved problems is clearly appearance of surface cracks at early stage after construction of new asphalt layers. This paper reviews the state-of-the-art of the problem of surface cracking of asphalt pavements, it assesses theoretical and imperial models and approaches describing the causes and remedies of the cracking problem and provides an in depth analysis to the main causes and mechanisms that induce such cracking. Finally, the paper discusses better ways to minimize and hopefully eliminate the causes of the occurrence of early surface cracks of asphalt pavements.