The use of IRC materials in PCC pavements has significant environmental and performance benefits. The amount of natural materials required and the amount of landfill space used are both decreased, leading to cost savings. Substituting one ton of coal fly ash or slag cement for one ton of Portland cement prevents almost one ton carbon dioxide emissions. Manufacturing slag cement uses only 15% of the energy needed to make Portland cement. Concrete made using slag cement and coal fly ash tends to be stronger, more durable and denser. Lastly, the concrete itself can be recycled, leading to a more sustainable approach to construction.