A cradle to gate LCA framework for emissions and energy reduction in concrete pavement mixture design

The plurality of life-cycle assessments for concrete pavements have used national or regional data to develop models to aid in decision related processes for designing concrete pavements. The findings of these studies effectively yield information in which global decisions can be made with respect to material selection and implementation. However, construction projects are dependent upon local supply and demand and require different levels of design complexity: freeze–thaw exposure, leaching potential, and alkali-silica reactivity. This paper presents a cradle-to-gate framework for design engineers and concrete ready-mix producers to implement in an effort to optimize mixture designs across economic, environmental, and mechanical performance criteria. The framework was assessed through the examination of a newly constructed highway in South Georgia. The case study proved that through the incorporation of 20% more Class F fly ash compared to the in-situ mixture design used on the pavement project site, all fresh and hardened concrete properties set by the Georgia Department of Transportation could still be exceeded, while the environmental efficiency would also increase by 23% with a total cost savings of 0.67 million dollars for the 11.52 linear miles (18.54 linear km) of pavement. Additionally, updated emission factors for input materials into concrete pavements, ranging from cement to aggregates, are presented using the most up-to-date data and techniques.