Each bitumen has a slightly different group composition, thus bitumen modifi cation with the SBS copolymer gives slightly different results in each case. Both in the industry and construction prac-tice there is still no simple method available which would allow the evaluation of the impact of SBS content and the group composition of bitumen on the structural and rheological properties of the polymer bitumen mix. The article presents the results of the dynamic viscosity tests of three bitumen types. Based on the analysis of the results obtained, it was found that changes in the rheological properties caused by SBS additive are characteristic for each of the bitumens tested and their chemical and group composition. They are also proportionate to the amount of the modifi er added. In order to have a possibility to measure this impact, three coeffi cients rheologically charac-terizing polymer and bitumen mixes were applied.
The academic environment of Wrocław emerged and developed in particularly difficult conditions of the post WWII era. Thanks to continuation of the tradition, experience and contributions of leading scientists from the former Jan Kazimier University of Lwów, it quickly achieved an important, internationally recognized position in particular in mathematics and chemistry. Two different sociological concepts of relations within the scientific community have developed simultaneously: (1) partnership between leaders and research team members, (2) hierarchical structure based on authority of a leader. History proved that both may be effective. Wrocław became a modern center of research management comparable to leading western universities. The general approach based on relationship „between master and a follower” has been replaced by the more effective relatioship „between a school and a follower”. Similarly to the Lwów tradition the Wrocław Scientific Society has played an integrative role in relations among scientists of different disciplines.