GB385329A - Improvements in or relating to the making or repairing of roads - Google Patents

Abstract

385,329. Roads ; surface-heating apparatus. KOMLOS, D., 21, Szinyei Merse, Budapest. June 20, 1931, No. 17918. Drawings to Specification. [Class 107.] A method of making or repairing roads comprises forming on or applying to a road bed or foundation an interstitial layer of alkalicontaining rock, such as felspar or like silicates, subjecting the layer to the action of heat by means of a furnace until melting and coagulating of the layer to the desired depth is effected, and then cooling, or allowing to cool, the fused layer. The term "alkali-containing rock" includes both rocks which naturally contain alkali and silica and also rocks in which one of these elements is naturally absent but to which has been added the necessary amount of alkali or silica or both. Suitable materials for the layer are felspar, granite, andesite, diabase or dolorite. When andesite is used for the layer, a temperature of 1350-1400‹ C. is necessary for four hours in order to melt the layer to a depth of 5 cms. The furnace may be left in position to protect the melted layer until the latter is quite cool, and if desired cooling may be accelerated by connecting the combustion chamber of the furnace to an exhauster. When the surface of the road consists of a material of a soil-like nature, holes are drilled into the soil and a layer of felspar applied. When the materials constituting the interstitial layer contain too high a content of alkali, a siliceous substance such as surface soil of a sandy nature, sand, quartz, sandstone, or finely-ground fireclay may be added to increase the viscosity of the melt. This addition may be effected by sprinkling the siliceous substance on the interstitial layer or by blowing the substance thereon during melting. If the application of this substance is continued after melting is completed but while the layer is still soft, a rough surface is produced on the road. Where the surface on which the road is to be prepared or repaired consists mainly of igneous rocky material, such as macadam, the layer to be fused is formed by loosening the earth or road to a depth of 8 to 10 centimetres. If the surface consists of a loamy, sandy, gravelly or soil-like material, the layer is formed by loosening the earth and adding a quantity of broken alkali-containing rock such as felspar. The furnace may consist of a rectangular body, which is closed on all sides except at the base and contains one or more burners. Spaces between adjacent sections of a road constructed as described above, or cracks or fissures formed in such a road, are adapted to be filled with a material such as surface soil, sand, quartz, sandstone or fireclay mixed with a binder such as lead oxide, and heat is applied thereto. The binder may consist alternatively of linseed oil and lead oxide.