Abstract: The invention provides a method comprising contacting, between 100° C. and 230° C. and under agitation, an elastomer, a functionalising agent and optionally, a peroxide compound. The functionalising agent is a thiolcarboxylic acid polyester or a reaction product of a thiolcarboxylic acid or ester with ethylene sulphide. The functionalised elastomer can also be pre-formed, then incorporated into the bitumen. The resulting compositions are usable directly or after dilution, for forming bituminous binders to produce surfacing, coating and waterproofing materials.

Abstract: The invention provides a method for producing bitumen/polymer compositions which consists of contacting, between 100.degree. C. and 230.degree. C. and under agitation, a bitumen or a mixture of bitumens with at least one styrene and butadiene copolymer having a global butadiene content ranging between 50% and 95 wt. % and a content of butadiene 1,2 double-bond structural units ranging between 12% and 50 wt % of the copolymer, and, preferably, also a sulphuring coupling agent or a functionalizing agent. The bitumen/polymer compositions are usable, directly or after dilution, for forming bitumen/polymer binders for surfacing materials.

Abstract: Functionalized elastomer/bitumen compositions with a broad plasticity range are produced by contacting a bitumen or bitumen mixture with an elastomer, a functionalizing agent and optionally a peroxide compound at 100.degree.-230.degree. C. under stirring conditions. The funtionalizing agent is a thiolcarboxylic acid having 3 or more carbon atoms, a thiolcarboxylic acid ester and specifically a disulphide having carboxylic groupings or carboxylic esters. The compositions may be used either directly or in diluted form to produce bitumous binders for making road surfacings, coated materials and sealing coatings.

Abstract: A process is provided for the preparation of bitumen-polymer compositions wherein bitumen is mixed at a composition between 100.degree. C. and 230.degree. C. with a block copolymer of styrene and a conjugated diene and a coupling agent containing a sulphur-donor compound for a duration of at least 10 minutes. The coupling agent is comprised of an elementary sulphur vulcanization agent and at least one sulphur-donor vulcanization accelerator from among morpholine disulphide, N,N'-disulphide of caprolactam and thiuram polysulphides.