Paving method and pavement construction for concentrating microwave

Abstract

A microwave energy reflecting zone (12, 12a, 12b) is provided below the surface of a pavement (11, 11', 11a, 11b) at a depth that is less than the maximum depth that such energy can penetrate into paving materials. The reflective zone, which is formed of electrically conductive material (16, 16a to 16h), results in energy and cost savings in subsequent paving or pavement repair operations that involve microwave heating of thermoplastic pavement and in which it is not necessary to heat down to the full depth to which such energy can penetrate paving materials. The heating is concentrated or localized within a predetermined upper portion of the pavement. The energy concentrating pavement may, for example, be more economically resurfaced when that becomes necessary by microwave heating followed by remixing and recompaction of the heated upper portion of the pavement material. The microwave reflective zone may be arranged to transmit a limited portion of downwardly propagating microwave energy to assure good bonding of the heated overlayer to the underlayer of paving material. Different microwave heating patterns, ranging from a highly uniform heating to heating which increases with depth, may be arranged for by locating the reflective zone at different depths.