2. A process as claimed in claim 1, wherein the binder used is an aqueous polymer dispersion.

3. A process as claimed in claim 2, wherein the aqueous polymer dispersion contains at least one copolymer of an acrylate or methacrylate with a C1-12 alkanol.

4. A process as claimed in claim 3, wherein the aqueous polymer dispersion substantially contains a. from 30 to 80 parts by weight of a1. an approx. 50 percent aqueous dispersion of a copolymer of approximately equal parts of n-butyl acrylate, vinyl acetate and vinyl chloride or a2. a copolymer of from 80 to 92 percent by weight of iso-octyl acrylate, from 7 to 17 percent by weight of acrylonitrile and from 1 to 3 percent by weight of a C3-5 Alpha , Beta -olefinically unsaturated carboxylic acid or a3. a copolymer of approx. equal parts of styrene and an acrylate containing from two to four carbon atoms in the alcohol radical with from 1 to 4 percent by weight of acrylic acid and b. from 20 to 60 parts by weight of b1. a 10-60 percent w/w aqueous dispersion of polyisobutylene having a molecular weight of from 50,000 to 200,000 or b2. a 30-50 percent w/w aqueous dispersion of a copolymer of from 60 to 80 percent of vinyl propionate and from 40 to 20 percent of vinyl chloride or b3. a mixture of (b1) and (b2).

5. A process as claimed in claim 2, wherein the aqueous polymer dispersion contains polyisobutylene.

6. A process as claimed in claim 1, wherein the binder used is bitumen in a molten, dispersed or dissolved form.