Treatment of rubber to form bituminous compositions

A method for forming a bitumen composition, which comprises:

• mixing rubber vulcanate particles with a hydrocarbon oil to effect softening and swelling of rubber particles,
• applying thermal energy and mechanical energy to said softened and swollen particles to effect at least partial dissociation of a rubber vulcanate network of the rubber vulcanate particles,
• dispersing said at least partially dissociated rubber vulcanate network in bitumen having
• at least one compatibilizing agent in said bitumen sufficient to incorporate treated rubber from said at least partially dissociated rubber vulcanate into said bitumen,
• effecting one or more additional incremental loadings of rubber vulcanate particles to the at least partially dissociated rubber vulcanate network-containing particles and effecting said thermal energy and mechanical energy application step on each such additional incremental loading of rubber particles to effect at least partial dissociation of a rubber vulcanate network thereof, and
• effecting said thermal energy and mechanical energy application step until all the rubber vulcanate particles have become dissociated to the extent that there is no discernible dispersed phase of rubber vulcanate particles as determined by the absence of sedimentation of rubber vulcanate particles after storage of said bitumen composition at 140.degree. C. for 2 days.