GB945795A - Improvements in means for heating pavements - Google Patents

Abstract

945,795. Electrically heated pavements. BAUSTAHLGEWEBE G.m.b.H. March 30, 1960, No. 11247/60. Heading H5H. [Also in Division E1] In an arrangement for electrically.heating a concrete pavement, a group of metal heating wires 2 in parallel formation and having a high electrical resistance is welded to a group of structural metal wires 3, 4 of such strength that they form together with the heating wires a mesh A which can be laid in its entirety without permanent deformation, and spaced therefrom in a plane parallel thereto, either above or (as shown) below, there is arranged a reinforcing mesh B consisting of structural steel, the spacing of the heating- wires 2 from one another being at least twice, and preferably from three to ten times, the spacing of the heating mesh A from the pavement surface O, and the spacing of the reinforcing mesh B from the heating mesh being less than the spacing of the heating mesh from the pavement surface. A reflector may be provided in the form of a large sheet of aluminium foil 8 with apertures 7 or in the form of small individual aluminium strips. The foil may be lined at its underside with paper. A mat 10 of straw or paper may provide thermal insulation, particularly in the absence of a reflector. In one form, Fig. 2, each mesh A comprises heating wires 2 of alloyed steel spot-welded to transverse wires 3 of conventional structural steel, aluminium or copper, and end wires 4 of structural steel or copper, the resistance of the wires 4 being not greater than the total resistance of the wires 2 in parallel. Connecting wires 9 are welded to the wires 4. Fig. 3 shows a reinforcing mesh B comprising longitudinal steel wires 5 spot-welded to transverse steel wires 6. In an alternative form (Fig. 5, not shown), the transverse wires 6 are arranged in spaced pairs. The wires 6 may lie at an angle other than a right-angle to the heating wires 2 which may have a coating of silicone oil to prevent adhesion to the concrete. As alternatives to wires, the reinforcing mesh B may be a perforated steel sheet or a sheet of expanded metal such as copper or aluminium.