Bituminous concrete esp for road making - using reduced amt of imported bitumen as an emulsion, and domestic asphalt powder

摘要

Bituminous concrete, in which the agglomeration of granulates is effected with less than half of th bituminous binder normally required, the lack of binder being compensated by asphalt powders and by using superstabilised emulsions of imported bitumen. The bituminous concrete is pref. obtd. by the cold agglomeration of granulates to which imported bitumen is added as an ionic emulsion treated with hydrolysed protein materials, and the water added for dispersion contains chromium salts. alternatively, the imported bitumen may be added as a cationic emulsion, also with Cr salts in the water employed for dispersion. The bituminous concrete is pref. used in road mfr. to stop the thermal cracking experienced with rigid coatings using hydraulic binders. The invention can be applied to all the layers used in road making, using domestically available asphalt powders and the min. amt. of expensive, imported bitumen.