International Summit on Cement Hydration Kinetics

Irvin A. Chen and Maria C.G. Juenger

The University of Texas at Austin

Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive and contributes significantly to green house gas emissions. One method of reducing the environmental impact of cement manufacturing is the use and adoption of an alternative environmental friendly binder, calcium sulfoaluminate-belite (CSAB) cement. CSAB cement has a different phase assemblage to portland cement which requires less lime for its formation. The relatively low lime requirement for CSAB cement production reduces energy consumption and carbon dioxide emissions from cement production. Moreover, CSAB cement can form and is stable approximately 200ºC lower than the temperature used for portland cement production, which further reduces energy consumption and carbon dioxide emissions from cement production. In this study, three CSAB cement clinkers with different phase compositions were synthesized. The range of phase compositions was chosen because it allows full evaluation of the phase compatibility and the inter-relationship between phase compositions and cement performance. The synthetic clinkers were analyzed for phase composition using x-ray diffraction and phase distribution using scanning electron microscopy. The synthetic clinkers were then tested for heat of hydration with isothermal calorimetry to determine their optimum gypsum contents and to study their early-age hydration behavior. The synthetic clinkers were made into cements by adding their optimum gypsum contents and the resulting cements were monitored for hydration product development using x-ray diffraction and scanning electron microscopy to understand property development. Performance of the synthetic cements was characterized through compressive strength, dimensional stability, and sulfate resistance.

chen-Poster