Potential of Portland-Limestone Cement to Improve Performance of Concrete Made With High Slag Cement and Fly Ash Replacement Rates

Abstract

Aggressive use of supplementary cementitious materials (SCMs) in concrete is becoming more appealing due to potential for cost effectiveness, reduced environmental impact, enhanced durability, and increased sustainability. Constructability, though, is often less attractive as time of set and early strength development can be delayed. This paper investigated the merits of incorporating portland-limestone cement (PLC) to improve concrete sustainability and performance when rounded gravel aggregates (most sustainable for some markets) were used in conjunction with dual SCMs proportioned for 50 % to 70 % total cement replacement. The family of concrete mixtures evaluated have not been widely studied with PLC (in the US or elsewhere). Mixtures containing PLC designed for improved synergies in the US construction market were compared to similar variations containing ordinary portland cement (OPC). PLC was shown to be able to produce concrete mixtures of greater compressive strength and lower set times compared to OPC in some, but not all, conditions. Individual mixture performance varied based on SCM use, PLC properties, and aggregate properties.