the development autoprotegees is filled by bitumen gun metal sheet expansion coefficient.

摘要

Metal sheet is bound to the asphalt layer by a continuous elastic layer of natural or synthetic elastomers, e.g. polypropylene, chloroprene, ethylene-propylene, butyl, block polymers. Examples are (1) Al sheet 8/100 mm. thick, 1 mm. elastic layer of 30% butyl; 70% petroleum asphalt, layer of reinforced aspha (2) metal sheet with elastic sheet deposited on it, composed of 75% petroleum aspha 25% polybutadiene-polystyrene block polymers.