A Framework for Comparative Life-Cycle Evaluation of Alternative Pavement Types

Saeed Alqadhi, Purdue University

Abstract

Researchers and practitioners agree that the selection of an appropriate pavement surface material type should be made based on a comprehensive evaluation that incorporates the costs and benefits associated with each alternative for the stakeholder. The most appropriate material type generally is the most cost-effective alternative over the pavement life cycle. Hypothetically, the most appropriate material type will vary across the various geographical regions of the U.S. because material costs and performance are influenced by the deterioration agents at play and the construction costs in a region. To address this issue, this dissertation proposes a comprehensive methodology to identify the most appropriate choice of pavement material type under different climatic and traffic conditions and thereby establish the conditions under which any one of two pavement materials can be considered superior. The case study of this dissertation uses data for an interstate highway section from the Long-Term Pavement Performance (LTPP) program database. The stakeholder costs include the agency cost, the user cost, and the community cost. The benefits (effectiveness) were evaluated using the concept of an area bounded by a performance curve and a pre-determined threshold. For each of the four LTPP zones and the two material types, the optimal maintenance and rehabilitation (M&R) schedule was established, and the corresponding optimal life-cycle cost-effectiveness was determined using both deterministic and probabilistic sensitivity analysis. The results using the former approach suggest that the most cost-effective pavement material types in wet climates and dry climates are rigid and flexible, respectively, irrespective of the discount rate. When the latter approach was used, the flexible pavement material was found to be the stochastically-dominant pavement material type irrespective of the climatic zone or discount rate. This framework can be scaled down to a state or scaled up to the national or continental level, given the availability of cost, traffic loading, pavement condition, and environmental datasets.

Degree

Ph.D.

Advisors

Labi, Purdue University.

Subject Area

Civil engineering|Transportation|Materials science

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