GB464963A - Improvements in and relating to mastic asphalt compositions - Google Patents

Abstract

A bituminous composition comprises cement, a bituminous emulsion of the mixing type and added water, the volume of water in the composition exceeding that of the cement and being at least 15 per cent of the volume of bitumen and aggregate in the mixture. Preferably the cement is first mixed with water to form a slurry, the slurry is mixed with the emulsion, and then aggregate and more water are added. The water used in preparing the slurry may be at least 50 per cent by volume of the cement. Five examples are given, of which the following is typical: (parts by volume) Portland cement 6, bituminous emulsion (containing 55 per cent of bitumen) 15, water 10,46, "bluestone" (basalt) aggregate 40. The aggregate may be sand, crushed slag, bricks, tiles, clinker, burnt clay, limestone, granite, gravel, cork, sawdust or rubber. The volume of added water may be at least 50 per cent of the volume of the emulsion. The emulsion may contain between 45 and 65 per cent of bitumen. The composition may be (1) mixed with more, relatively coarse aggregate, and may be of such a consistency that when the mixture is laid as a roadway the coarse aggregate sinks to the bottom; or (2) applied to a recently-laid, soft, cement concrete roadway or other surface, thus binding with the latter; or (3) laid as a roadway, coarse aggregate being then lightly scattered thereon and pressed into the surface thereof to form a hard, mosaic-like finish.