Crack sealing in flexible pavements: A life-cycle cost analysis

Pavement cracks are usually sealed to prevent water from entering base course layers. Experience suggests that water in pavement layers hastens pavement deterioration and, therefore, increases rehabilitation costs. Initially the Ministry of Transportation, Ontario (MTO), Canada, had limited success in sealing cracks because inappropriate materials and installation procedures were used. This setback during the initial stages of development in crack sealing raised questions about the effectiveness of crack sealing in reducing the rate of pavement deterioration. In the 1970s and 1980s MTO carried out several field studies to develop an effective crack sealing procedure and to study the influence of crack sealing on pavement distress and performance. The cost-effectiveness of this treatment was investigated as well. The results of the studies indicate that sealing cracks is a viable and cost-effective preventive maintenance treatment and can extend the service life of asphalt pavements by at least 2 years. However, for optimum benefits the crack sealing program must be implemented according to guidelines proposed. The guidelines provide a basis for the selection of suitable pavements and cracks, sealant materials, and application procedures.