Context
Growing environmental concerns have led to a shift in government priorities. Ecological considerations, such as resource conservation and reducing greenhouse gas emissions, are now important factors when awarding contracts for public works projects, including motorway construction. This project was developed in response to this changing landscape, with the goal of integrating environmental impact assessment into the decision-making process for road construction materials.
Objectives
The project aimed to develop a method to measure the environmental impact, specifically the global warming potential (GWP), associated with the production and transportation of asphalt and concrete, the two most common road building materials. To achieve this, researchers developed a systematic approach for analysing material flows. This involved defining clear system boundaries, identifying key observation points during production, and gathering data through literature review and on-site observations. The analysis considered the entire life cycle of the materials, from raw material preparation (including aggregate recycling) to delivery, mixing, transport to the construction site and the influence of different energy sources on the overall GWP.
Implementation
The project faced the challenge of presenting the complex findings in a clear and usable way for decision-makers involved in awarding construction contracts. To address this, researchers developed easy-to-use models for assessing the GWP of both asphalt (particularly when including recycled asphalt) and concrete production. Recognising the variety of influencing factors, they created a user-friendly Microsoft Excel-based calculation tool to allow for scenario analysis. This tool enables construction authorities to calculate the equivalent CO2 emissions associated with asphalt and concrete production for specific projects.