Life Cycle Analysis of Low Carbon Roller Compacted Concrete Pavements

Abstract

Roller compacted concrete (RCC) is a zero-slump concrete with lower ordi-nary Portland cement (OPC) content and water/cement, and a higher propor-tion of aggregates than conventional concrete. Life cycle analysis (LCA) was performed with a cradle-to-gate system boundary to compare the impacts of continuously reinforced concrete pavements (CRCP) and RCC pavements per mile of dual carriageway. RCC pavements have less than half of the en-vironmental impact of CRCP due to lower thickness of RCC pavement lifts and lower quantity of OPC. Construction processes contributed to only a very small proportion of the total environmental load for both pavement types. In RCC pavements, notable reductions in the GWP were observed with partial replacement of cement. Compared to fly ash and ground granu-lated blast furnace slag, limestone calcined clay cement has the lowest CO2e emissions for concretes with similar compressive strength, due to its shorter transport distances. The benefits of using recycled concrete aggregates and reclaimed asphalt pavement aggregates in RCC pavements were outweighed by their long transport distances. The geographic availability of materials is critical to consider when replacing OPC and natural aggregates to reduce RCC pavement environmental impacts.