Belite Cement, and Concretes; Novel Low-Energy Approaches to Making Concrete Extremely Durable

The overarching project objective is the commercial development of an extremely durable concrete packaged product based on a low-carbon, low-energy belite-based cement alternative to ordinary Portland Cement (OPC). The alternative, belite-rich clinkers, such as calcium sulfoaluminate belite (CSAB), will be fabricated from traditional raw materials including limestone and fly ash with rapid quenching after the belite phase is developed in the kiln; additional approaches will incorporate the use of industrial byproducts to produce calcium sulfoaluminate belite cements. Belite-rich clinkers can be produced at much lower operating temperatures, 1250oC instead of 1450oC, and develop softer clinkers which require less energy to grind to cement fineness. However by eliminating the alite phase, found in traditionally found in Portland clinker, the slow-strength forming belite phase will require a novel additive to inducing early-age strength development. This coupled with an engineered aggregate package the commercialized concrete product will provide a novel approach for greatly increasing the durability of concrete, by doubling the expected service life. A percent CO2 Reduction for this process of 60%, was calculated based on U.S.DoE published Cost and Performance Metrics, [1] using OPC as a baseline comparison. A CO2 Avoided Potential of 40% was also calculated. This translates to a CO2 savings of 434,000 tons per year from 1 million tons of CSAB cement production; which represents approximately 57% decrease of CO2 emitted from CSA production as compared to OPC production. This would also result in the consumption and beneficial use of between 170,000 and 400,000 tons of industrial waste, depending on the cement composition. The cost advantage of FGD/FBC utilization, combined with the lower clinker temperature of CSA results in a lowered overall cost, competitive with that of OPC. The project will build on established industry relationships (University of Kentucky Center for Applied Energy Research; Natural Process Design; Sandia National Laboratories; Titan Cement; and LaFarge Cement) that create an exceptional research environment where scientists and engineers work on scientifically challenging problems with substantial potential for innovation in CO2 reduction through the development of commercial belite cements leading to extremely durable concrete products.