Characterizing the Influence of Set-Control Admixtures on Rapid Hardening Hydraulic Cements
Argha, Debo Brata Paul
Concrete is the most used man-made material on Earth, and cement accounts for nearly 25 percent by the weight of concrete. The cement manufacturing industry emits approximately 363 kg of carbon dioxide (CO2) per 454 kg of cement produced, making it one of the two largest CO2 emitters in the world (Boden et al., 1751; Damtoft et al., 2008; Juenger et al., 2011). The cement industry is under increasing pressure to reduce its tremendous carbon footprint. As a result, there is a burgeoning interest in the development and characterization of alternatives to portland cement (i.e., alternative cementing materials (ACMs)). A promising type of ACMs are known as rapid setting hydraulic cements (RSHCs), including calcium sulfoaluminate cement (CSA) and calcium aluminate cement (CAC). These RSHCs have the potential to reduce the negative environmental impacts of concrete through lower kiln burning temperatures and calcium carbonate (CaCO3) to produce quicklime resulting in less CO2 emissions. Despite the potential advantages of RSHCs, concerns about their long-term performance in the field along with the limited understanding of the scalability have prevented a wider implementation of the materials. The primary goal of this study is to comprehensively characterize the early age behavior of RSHCs (e.g., CSA, CAC). Specially, the effect of set modifiers on the heat of hydration, compressive strength, workability, and drying shrinkage properties were investigated on a large variety of blended RSHCs that are produced in the United States. Among all RSHCs that are investigated in this study, CSA2 with a dosage of 2% HRWR and 0.5 % set retarder is recommended in larger scale application.
rapid setting hydraulic cements, set control admixtures, isothermal calorimetry, cement hydration, setting time
Argha, D. B. P. (2022). Characterizing the influence of set-control admixtures on rapid hardening hydraulic cements (Unpublished thesis). Texas State University, San Marcos, Texas.