| 摘要 |
<p>Bituminous coating of roads comprises applying a double layer of the same thickness as a single layer, i.e. about 4 cm., the lower layer comprising a very flexible material of particle size that can resist traction and the upper layer comprising a material of higher particle size but preserving flexibility properties, to accomodate deformations of the lower layer. The components of both layers are agglomerated using a binder contg. a styrene-butadiene copolymer. The process pref. comprises (1) emulsifying an SB latex, (2) mixing a 180/220 bitumen and Trinidad bitumen (addition of a binder for the upper layer, known as G oil, 5 pts. per 100 pts. of bitumen mixt.), (3) prepg. granules for the 2 layers, (4) coating the granules with the bitumen mixt. and (5) applying the 2 layers by known methods.</p> |
