Patent GB-1368356-A (GB)
Title: Method of laying asphaltic mastic strips
IPC: E02B3/12
Filed: 1972-02-02
Abstract: 1368356 Revetments BITUMARIN NV 2 Feb 1972 [4 Feb 1971] 4952/72 Heading E1H [Also in Divisions B6 and C3] A water-retaining surface is impermeabilized with a reinforced layer of asphalt by unwinding an asphaltic mastic strip externally reinforced on one side only from a reel having a diameter of at least 1 metre on to the surface to be lined in such a way that the reinforced side faces this surface, the asphaltic mastic consisting of sand, filler, and a bitumen mixture composed of a straight-run bitumen and blown bitumen and having a thickness of at most 2.5 cm. After strip has been laid, another strip may be laid in a joining arrangement and the joint between the two strips can be impermeabilized, e.g. by pouring or spreading heated asphaltic mastic into the joint. Two layers of the reinforced strips may be laid one on top of the other the reinforcement of the upper strip facing the mastic side of the lower strip and preferably the upper layer of strips being so laid that a joint between two lower strips is covered by an upper strip. The asphaltic mastic may consist of 30-40% by weight of broken sand with a particle size of up to 3 mm, 15-30% by weight of fine sand having a particle size of up to 2 mm, 18-32% by weight of limestone filler and 12-16% by weight of a bitumen mixture consisting of equal quantities by weight of straight-run 80/100 bitumen and blown bitumen and blown 85/40 bitumen. The reinforcement is preferably a gauze, e.g. metal gauze, the meshes of which are so dimensioned that at least the greater portion of the mineral matter can pass through the meshes. The strip may be produced by pouring the asphaltic mastic in hot condition on the reinforcement present on a concrete floor having upright metal edges in which the height about the floor surface is equal to the thickness of the strip to be prepared, moving a heated screed over the applied edges of the floor, winding the strip after cooling off on to a reel which may be rotatably suspended in a vehicle which is being moved over the floor. Preferably the reel has flanges and before the strip is wound off it is preferably covered with a plastics film, e.g. polyethylene or polypropylene to prevent sticking. During unwinding of the mastic strip the unwound portion may be heated before being laid and the unwound strip may be pressed by means of a roller on to the surface being lined. Preferably the reel has flanges and before the strip is wound off it is preferably covered with a plastics film, e.g. polyethylene or polypropylene to prevent sticking. During unwinding of the mastic strip the unwound portion may be heated before being laid and the unwound strip may be pressed by means of a roller on to the surface being lined. Preferably the surface on which the strip is being laid is heated before laying. As shown in the drawing, the surface of a dam is provided with a layer 3 of broken stone and a levelling layer 4 consisting of asphalt. The vehicle at position A comprises a chassis 5, a reel 6 with flanges 7 resting with its shaft 8 in supports 9, an infrared heater 10 which at A is in the inoperative position, and steering gear 11.. A rolling device 12 is connected to the vehicle. The vehicle is connected to a cable 14 which is wound on a winch (not shown) via a block 15. When the vehicle is put into operation the infra-red heater 10 is directed to the surface 4, the free end of the reinforced asphaltic mastic strip wound on to the reel 6 is attached to the crest of the dam at 17 and the cable 14 is paid out. As shown at B in the drawing the unwinding strip 18 is laid on the surface 4 which is heated by infra-red heater 10 and the laid strip is pressed down by the rolling device 12. In position C the infra-red heater is set in the inoperative position and the end of the strip is attached to a supporting body 19.