Process for improving the properties of asphalt and similar bituminous products

摘要

The hardness, strength and elasticity of bituminous materials, e.g. asphalt, are increased by the addition of 1 to 25 per cent by volume of an inorganic filler, insoluble in bitumen, and of a mean particle size between 0,002 and 0,1 micron. Specified fillers are silica, alumina, titania, ferric oxide, calcium and barium sulphates and carbonates, magnesium carbonate, calcium, aluminium and complex silicates singly or in admixture. They may be added to heated asphalt or asphalts diluted with solvents, e.g. benzene, kerosene or white spirit, which are subsequently driven off. Coarse filler may also be present.