Abstract:
Recent work has indicated that the excess water window for typical ceramic forming processes, such as extrusion and tape casting, can be predicted using a specific volume diagram. Excess water is defined as the volume of water above that is needed to fill the pore volume. it is proposed that there would be a similar window that correlates with slump behavior for highly loaded systems, such as cements. This thesis identifies a slump window for a typical cement system (gravel, sand, and Portland cement) using a statistical experimental design approach allowing slump behavior to be evaluated over a broad range of compositions and packing efficiencies. The excess water content window for equivalent stiff slump (defined as a slump of 15 to 45 mm) was 3 v/o (±2 v/o) over the entire composition space. It was also observed that the measured improvement in packing efficiency associated with the addition of water to a dry system was also 3%, exactly the excess volume necessary for equivalent stiff slump. Finally, due to the overlap of the particle size distributions of gravel and sand (aggregate) used in these experiments, it is demonstrated that these cement compositions could be treated as a binary mixture, with the observed optimum in packing efficiency at approximately 80:20 (aggregate:cement) as would be predicted for a binary packing system.
Description:
Thesis completed in partial fulfillment of the requirements for the degree of Master of Science in Ceramic Engineering at the Inamori School of Engineering, New York State College of Ceramics at Alfred University
