| 摘要 |
1. A process for producing surfacing material for road surfaces and the like, comprising the following features : granular mineral (20) of selected grain sizes is heated ; the heated granular mineral (20) is mixed with an encasing material (21) ; bitumen (22) is added as a binding agent to the granular mineral (20) ; the mineral (20) and the bitumen (22) are mixed in a mixer (9) ; characterized by the following features : the encasing material (21) which is semi-hard to soft at ambient temperature and which already has a tendency to stick at elevated temperature comprises amorphous polyolefins which as copolymers of alpha-olefins with selected monomers have the following parameters : melt viscosity about 8000 mPa s (measured with a rotary viscosimeter at about 190 degrees C), softening point about 105 degrees C (measured with ring and ball in accordance with DIN 52011), penetration 20 (according to DIN 52010), breaking point -30 degrees C (measured in accordance with Fraass, DIN 52012) ; the added amount of the encasing material (21) is about 7% of the total binding agent content of the surfacing material (23). |
