Some cracks are indicative of structural failure in the pavement, such as fatigue cracking, thermal cracking, or cracking due to base failures. Other cracks, such as reflective cracks, are mainly cosmetic in nature. They can be present for many years without the need for significant maintenance, yet they do not reduce the pavement's smoothness or ability to handle traffic. The use of properly designed and constructed cement-stabilized bases can actually reduce the occurrence of failure-related cracking. Fatigue cracking is decreased because the stiff, stabilized base reduces vertical deflection and tensile strain in the asphalt surface. Base failures are decreased because cement stabilization helps keep moisture out of the base and improves base material performance in saturated or freezing conditions. In addition, subgrade failure is decreased because cement-stabilized bases spread traffic loads over wide areas and can span weak subgrade locations. However, cement-stabilized bases can also be the source of shrinkage cracks in the stabilized base layer, which can reflect through the asphalt surface. There are a number of measures that can be taken to minimize the chance that cracks will occur in a cement-stabilized material. A well designed, constructed, and properly maintained cement-stabilized base will normally outlast several asphalt overlays, providing decades of low maintenance service. This paper will look at the types and causes of reflective cracking in cement-stabilized pavement bases and what techniques are available to minimize them for improved pavement performance. For the covering abstract of this conference see ITRD number E220308.
Abstract