1997 Volume 34 Issue 2 Pages 97-106
Raw powder, such as ordinary portland cement, admixture, fine aggregate, dispersant, thickener and vinylon fibers for building materials, was treated by different mixing methods with a high-velocity pneumatic double-stage impactor. The process of becoming globular has been practically applied to building materials to investigate the effects on the basic physical properties including pore size distribution, specific surface area, minimum water/cement ratio and plasticity, of the treated composite powder due to modification, so as improve the frost resistance and the strength of the building materials.
The results indicate that the process of becoming globular can reduce the minimum kneading water/cement ratio. This is because the composite powder is densified by the particles impacting during the modification process, and because the volumes of micropores in the particles and among adjoining particles are reduced, and pore sizes are shifted minutely.
