| abstract |
A method of rolling a plastically deformable material which behaves as a single phase and which is deformed plastically when subject to deformation forces, which material comprises from 40% to 70% by weight of hydraulic cement and/or fly-ash particles A of from 0.5 to 100 mu m, silica particles B of from 50 ANGSTROM to 0.5 mu m (which are at least one order of magnitude smaller than the cement/fly-ash particles A), a surface-active dispersing system present in an amount sufficient to impart to the composite material a plastic consistency in a stress field of up to 200 kg/cm sq., and from 7% to 20% by weight water; the silica particles B being homogeneously arranged in the voids between the densely packed cement/fly-ash particles A, and the amount of water substantially corresponding to the amount necessary to fill the voids between the solid particles of the composite material. In accordance with the method, the composite material is introduced into a wedge-like space defined between oppositely arranged surface parts, at least one of which is gas-permeable, e.g., a continuous band or belt, and the surface parts are moved relative to the material so as to entrain or roll it towards and through the throat or gorge of the space. The plastically deformable material retains substantially all of its original water content and continues to behave as a one-phase, plastically deformable material after rolling, and possesses a substantially smooth and uniform outer surface without material defects. |