LowEmissionAsphalt-136pg-WhitePaper-May2023

P a g e | 49 Concrete Paving Industry Emissions & Solutions As of 2019, domestic cradle-to-gate or production stage emissions from Portland cement concrete (PCC) was ~5 million metric tons (MMt) of CO 2 e, up 19% from a decade earlier. According to the Portland Cement Association (PCA) and the American Concrete Pavement Association (ACPA) , the value chain for concrete includes five stages, beginning at the cement plant and extending through the entire life cycle. The five links in the value chain include: • Production of clinker , the key chemically reactive ingredient used to produce cement. • Manufacture and shipment of cement, which binds a concrete mixture together. • Production of concrete by mixing cement with other ingredients primarily aggregates and water. • Construction . • Carbonation , where concrete structures absorb CO 2 . The PCA’s Roadmap 103 calls for accountability at each step of the value chain from the first production stages to the final reuse and recycling phase to achieve the industry’s goal for net zero carbon emissions by 2050. Cement-Concrete Process Value Chain Source: PCA Increased Limestone The ingredient with the most significant carbon impact in Portland cement concrete (PCC) is cement. A simple way to reduce its impact is to use Portland-limestone cements (PLCs). PLCs have an increased amount of limestone in a cement blend that decreases carbon emissions with manageable effect on performance. Use of 103 Portland Cement Association (PCA): Roadmap To Carbon Neutrality – A more sustainable world is Shaped by Concrete, www.cement.org , and American Concrete Pavement Association (ACPA): Concrete Pavement’s Role in a Sustainable Future , www.acpa.org/sustainability-white-paper/.