Studies on membranes composed of polymer-bitumen blends

A computer-controlled bending system has been constructed for characterizing the bending properties of commercial membranes composed of polymer-bitumen blends supported by a non-woven polyester type base. The system allows the bending elasticity and yield point to be obtained for a membrane, and also permits the stress relaxation after a distortion to be characterized. These properties are related to the polymer present in the bitumen.