Modified bitumen is produced in asphalt-concrete plants by special units.
To produce polymer-bitumen binders of proper quality the following materials are used: viscous road bitumens and block copolymers of SBS type, surfactants and plasticizers (if required).
When choosing equipment and production capacity, technical and economic parameters of production, as well as the required production volume must be considered.
There are currently two approaches to the production of modified bitumen. The first one is called single stage, since all initial components taken in the required amounts are blended in one tank. If plasticizer is required, it is added to bitumen first, then the product is blended to uniformity. Then the polymer batch is added in the form of crumble or powder, with constant mechanical agitation.
If the block copolymer of SBS type does not contain a surfactant, the missing component is added at the last stage of polymer bitumen binder production, and the mix is homogenized.
The double stage method involves preliminary preparation of polymer solution in plasticizer, or bituminous polymer solution in a mix of plasticizer and bitumen. Component concentrations are compliant with the concentrations selected for the polymer bitumen binder. This solution is mixed with dehydrated hot bitumen. At the end of the process, a surfactant is added and the mix is uniformly blended.