Sustainability of Perpetual Pavement Designs: Canadian Perspective

Sustainability of road construction is one of the key factors affecting the global environment, economy, and future social development. Several research projects are currently under way to study different construction approaches, materials, and designs that can improve the sustainability of roads. Although perpetual pavement is characterized by higher construction costs compared with conventional flexible pavement designs, it requires less maintenance and less frequent rehabilitation if designed and constructed properly. Pavement design can conserve materials and energy used for maintenance over the pavement life cycle and reduce the noise and emissions that accompany maintenance activities. Highways are typically subjected to heavy truck loads, which results in rapid structural deterioration. Because of the importance of highway conditions, the structural capacity of highway pavements should be maintained to the highest standards to ensure safety and a high level of service. Perpetual pavement designs are capable of achieving high structural capacity and can resist deterioration with minimum surface treatment. The case study presented examines how perpetual pavement design is a feasible solution for sustainable roads. The construction of a test section on Highway 401 in Woodstock, Ontario, Canada, is explained and analyzed. Three sections, representing conventional pavement design, perpetual design without rich bottom mix, and perpetual design with rich bottom mix, were constructed next to each other for a comparison of their performance with different sensors. Recycled asphalt pavement was used in all pavement layers in this project. The use of recycled materials enhanced the pavement mechanical characteristics and maximized the efficient use of resources.