Title: Portland-Limestone Cement Fineness Effects on Concrete Properties
Author(s): Bradley S. Hansen, Isaac L. Howard, Jay Shannon, Tim Cost, and Wayne M. Wilson
Publication: Materials Journal
Appears on pages(s): 157-168
Keywords: Blaine fineness; fly ash; portland-limestone cement (PLC); slag cement; sustainability
Portland-limestone cement (PLC) performance is controlled, to a significant extent, by limestone content and fineness. There are questions about how much fineness is needed or beneficial, with the most commonly used guidelines focused on how to achieve performance comparable to ordinary portland cement (OPC). This paper provides guidance on the production of PLC with potential concrete strength performance exceeding that of OPC and also considers (secondarily) concrete workability, setting, and durability performance. A database of related previous work was evaluated, and additional experiments were done with dedicated grinds of PLC at a single plant, from similar clinker, of varying fineness and controlled limestone contents. Findings from concrete and cement paste testing showed that the change in fineness (m2/kg) (ΔF) in relation to the change in limestone content (% limestone) (ΔL) relative to OPC can be a useful index for performance bench-marking. Specific guidance is provided where ΔF/ΔL values are in the general range of 10 to 30 and ΔF values are 110 to 175 m2/kg. Recommendations for some ΔF/ΔL values are also considered.