Development of a dynamic model for assessing the environmental consequences of the pavement life cycle

Hessam AzariJafari (PhD student, civil and building engineering, USherbrooke)

Supervisor: Ben Amor

Co-supervisor: Ammar Yahia

Context

In the case of a large-scale life-cycle assessment (LCA), aimed at studying the environmental impacts related to new decisions related to road infrastructure, for example, it is important to consider the environmental impacts of induced changes on the market by these decisions. These changes may relate to a change in demand for several materials with the same function and / or the volume of co-products generated.

Goal

The goal is to develop a dynamic consequential LCA model allowing to take into account, in the environmental impacts, the changes induced on the market by new decisions related to the selection between a pavement in concrete or asphalt.

Methods

Consequential LCA (C-LCA) is used to integrate the direct and indirect environmental consequences related to the selection of a type of pavement. In this research project, a dynamic C-LCA model is developed to evaluate the environmental consequences following the selection of a concrete or asphalt roadway. In addition, this dynamic C-LCA model was developed to consider the different sources of uncertainty and variability related to data quality, modeling parameters and behavioral variability during the life cycle of both types of pavement.

Applications

The results show that the non-consideration of changing environmental consequences over time during the life cycle of both pavements can lead to an overestimate of the environmental damage results. The environmental impacts resulting from the substitution of the status quo (asphalt) scenario by the alternative (concrete) are then overestimated by 37, 115 and 142% form, respectively, the climate change, ecosystem quality and human health impact categories. The sources of variability contribute to 37-68% of the variance of the four categories of damage (climate change, ecosystem quality, human health and resource). However, despite the spread of various sources of uncertainty and variability in the results, the conclusion on which scenario has the best environmental performance has remained unchanged.

Partner

Ministère des Transports du Québec