Pavement preventive maintenance: description, effectiveness, and treatments

The level of funding by various highway agencies is inadequate to keep roads at the current condition if current maintenance and rehabilitation policies are continued. Through a preventive maintenance program, pavements can be maintained in a cost-effective manner leading to a better pavement quality at lower total costs. Preventive maintenance is a program strategy that can arrest light deterioration, retard progressive failures, and reduce the need for routine maintenance activities. The objective of such a program strategy is to extend the functional life of the pavement by applying treatments before the pavement deteriorates to a condition that requires a corrective treatment, such as a structural overlay. An effective strategy would feature a combination of different treatments, such as periodic crack treatment followed by chip sealing. A number of highway agencies have used preventive maintenance strategies for both low and high volume roads and found them to be successful. Preventive maintenance treatments for flexible pavements include fog seal, chip seal, slurry seal, micro-surfacing, crack treatment, and thin hot-mix dense, open and gap graded overlays. The selection of a preventive maintenance treatment should be based on the condition of the existing pavement, traffic volume, and environmental conditions. Other factors include experience, budget constraints, and political reality.