| 摘要 |
<p>PROBLEM TO BE SOLVED: To measure the average density of a pavement layer without destroying the layer by placing an auxiliary density-measuring plate of a known dielectric constant on a layer to be measured, and measuring electromagnetic waves reflected. SOLUTION: An auxiliary density-measuring plate of a known dielectric constant is placed on a layer to be measured, and electromagnetic waves reflected are measured; i.e., reflected amplitude at the interface between the auxiliary density-measuring plate and the layer to be measured, and that at the interface between the layer to be measured and a layer therebelow are measured. Further, the reflection time of the waves from the interface between the auxiliary density-measuring plate and the upper surface of the layer to be measured to the interface on the lower surface of the layer to be measured is measured. The average dielectric constant of the layer to be measured is calculated on the basis of these measurements, and the density of the layer is calculated from the relational expression of the dielectric constant and the density. By calculating the dielectric constants of the top and bottom surfaces of asphalt concrete from reflected amplitude at the interface between the auxiliary density-measuring plate and the asphalt concrete and that at the interface between the asphalt concrete and a roadbed, for example, degrees of compaction of the top and bottom surfaces of the asphalt concrete can be determined.</p> |
