What is the definition of poly-modified bitumen?

Poly-modified bitumen is defined as a bitumen that has been modified with polymers, which enhances its properties and performance. The modification process involves adding polymer materials to the base bitumen, resulting in improved elasticity, tensile strength, and resistance to temperature fluctuations. This makes poly-modified bitumen particularly advantageous in roofing applications, as it can better withstand the stresses caused by weather changes, thermal cycling, and structural movement.

While bitumen treated with heat, which may improve its application characteristics, does not specifically convey the properties imparted by polymer modification. Also, bitumen without any additives would not provide the enhanced qualities and performance associated with poly-modified types. Lastly, describing poly-modified bitumen as a type of roofing felt is inaccurate, as roofing felt refers to a different product that may or may not contain bitumen at all. Overall, recognizing that the defining feature of poly-modified bitumen is the inclusion of polymers clarifies its distinct advantages for roofing applications.