| Description |
xiv, 105 leaves : illustrations ; 29 cm |
| Summary |
"A test method has been developed to measure air permeability of refractory concretes using a vacuum decay approach. An acquired vacuum decay curve is used to calculate permeability as derived from Darcy's law and van der Waal's law. The uncertainty involved with random errors in the determination of the permeability is approximately 1.3%. Reproducibility experiments revealed the test method produces consistent results and is capable of detecting small changes in permeability. Effects of organic fiber additions on permeability of refractory concrete were also studied. Organic fibers were added in three concentrations (0.05, 0.1, and 0.2 wt. %) to a 5 wt.% calcium aluminate cement castable containing 5 wt.% silica fume. Results indicate that organic fiber addition is an effective means for increasing the permeability of castables. Apparent porosity data was used to determine which fiber types and concentrations yielded the greatest permeability increases with the lowest residual porosity. The data indicate that the 1.2 denier polypropylene fiber at a concentration of 0.1 wt.% yields the best overall result, increasing the permeability by two orders of magnitude (0.03 millidarcy at the baseline to 3 millidarcy after heat treatment) while only moderately increasing apparent porosity (11.2% at baseline to 12.5% after heat treatment)"--Abstract, leaf iv. |
|
