| 摘要 |
Asphaltic concrete constituents (13) or the like deposited in a windrow (14a) along a surface (12) to be paved are molded into a preliminary narrow layer (14b) of greater height than the final layer (14d) of pavement to be formed on the surface and are then heated by directing microwave energy into the preliminary layer. The heated preliminary layer is then spread out to form the final thinner layer of paving material for smoothing and compaction. Molding means (37) for the preliminary layer and microwave heating means (38) may be carried on a vehicle (16) which travels along the windrow. The vehicle may also carry mixing, spreading and compaction means (39, 92, 89) or some or all of these elements may be on a separate paver vehicle. The method and apparatus reduces an unproductive dissipation of energy, which can occur if microwave heating is performed with the paving materials spread out in the relatively thin final layer, by avoiding unnecessarily deep penetration of the microwave energy into the underlying surface that is to be paved. Auxiliary heating means (79), preferably using thermal energy recovered from the exhaust of engines (28) which drive the electrical generators (29) that energize the microwave sources (52), may be used to preheat portions of the surface adjoining the portion overlain by the preliminary layer.
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