Cement Materials: Low Carbon Cement and Alternatives-Low Carbon Webinar Handout

Low Carbon Webinar Handout

Pdf Summary

Larry Rowland’s presentation discusses where cementitious materials for the precast industry are headed, with a strong focus on sustainability, embodied carbon, and resilience. He emphasizes that precast concrete is a durable, fire-resistant, storm-resilient, and long-lasting material, making it well suited for increasingly climate-challenged conditions. At the same time, the industry must address the environmental impact of cement, the largest contributor to concrete’s embodied CO2.<br /><br />The presentation explains how life cycle assessment (LCA) and environmental product declarations (EPDs) are used to measure and compare global warming potential (GWP), and how reductions can be achieved through material and process choices. Key strategies include lowering clinker content, using blended cements such as Portland-limestone cement (Type IL), and incorporating supplementary cementitious materials (SCMs) like slag cement and fly ash. Examples show that replacing ordinary Portland cement with lower-carbon alternatives can significantly reduce mix GWP.<br /><br />Rowland also outlines upcoming specification changes that will make blended cements more common, especially Type IL. He notes that while these cements are beneficial, mix designs may need adjustment in water demand, admixtures, and strength development. Slag cement is presented as a high-performance, low-GWP SCM with long-term importance, while fly ash remains valuable but faces future supply challenges as coal use declines.<br /><br />The presentation also introduces emerging alternatives such as calcined clays, novel low-carbon cements, and Heidelberg Materials’ ReConcrete concept, which uses recycled concrete paste as a circular-economy material. Finally, he highlights carbon capture, utilization, and storage (CCUS) as essential for achieving net-zero goals, with near-zero cement products already entering the market. Overall, the message is that precast can reduce carbon while maintaining performance through proven materials, better specifications, and new technologies.

Keywords

precast concrete

sustainability

embodied carbon

life cycle assessment

environmental product declarations

global warming potential

Portland-limestone cement

supplementary cementitious materials

carbon capture utilization and storage

low-carbon cement