Permanent plastic formwork system

Abstract

The present disclosure relates to a permanent plastic formwork system formed by two parallel surfaces, namely an outer surface and an inner surface, comprising a plurality of flat or longitudinally curved, hollow plastic slats obtained by means of extrusion, provided internally with a rebar mesh providing them with rigidity and joined longitudinally by means of tongued-and-grooved ends with separators existing between the two surfaces. The separators are provided with a threaded area and an inclined appendage for securing the rebar mesh located between the surfaces. The slats are secured to the ground using U-shaped parts containing a threaded rod that can be used to clamp and fix the same. In addition, in closed structures, reinforced internal elements can be incorporated diametrically, such as metal bars with flat surfaces at their ends enabling the same to be secured to the above-mentioned inner surface.

1 . Permanent plastic formwork system, of the type made up of a frame consisting of two parallel surfaces, an outer surface ( 1 ) and an inner surface ( 2 ), between which there is installed a rebar mesh ( 3 ), leaving the gap between them prepared for pouring the fresh concrete therein which, when hardened, will form the walls of the structure to be built, said frame subsequently being suitably removed, characterized in that each of said parallel surfaces ( 1 ) and ( 2 ) consists of a plurality of slats ( 4 ) suitable in number so as to form the appropriate structure in each case, preferably made of plastic and obtained by means of extrusion, which slats are hollow and identical and are joined longitudinally to one another by means of the tongued-and-grooved ends ( 4   a ) and ( 4   b ) that they have. 
     
     
         2 . Permanent plastic formwork system according to  claim 1 , characterized in that the male end ( 4   a ) of the slats ( 4 ) have a inner arrow shape ( 14 ) arranged between respective longer walls ( 15 ) bent at their ends ( 16 ), and the female end ( 4   b ) has an arrow-shaped channel ( 17 ), suitable for receiving the aforesaid arrow ( 14 ), and two pairs of grooves ( 18 ), some more outer grooves and some more inner grooves, intended to receive the bent ends ( 16 ) of the male end ( 4   a ), to engage in two different positions, a more open position and a more closed position. 
     
     
         3 . Permanent plastic formwork system according to  claims 1  and  2 , characterized in that it is provided that there are arranged between the parallel surfaces ( 1 ) and ( 2 ), between each of the mentioned slats ( 4 ) forming them and at different levels, a series of separating elements or separators ( 5 ); in that said separators ( 5 ) are made up of a tubular body, the length of which will determine the thickness of the wall, having at each of their ends a threaded area ( 6 ) suitable for inserting a nut ( 7 ) in order to fix them to the corresponding slats ( 4 ). 
     
     
         4 . Permanent plastic formwork system according to  claims 1  to  3 , characterized in that the separating elements or separators ( 5 ) in the central part of the tubular body forming them have an appendage ( 8 ) generated therefrom in an inclined manner that is especially intended to serve as a support for securing the rebar mesh ( 3 ) which is located between the surfaces ( 1 ) and ( 2 ). 
     
     
         5 . Permanent plastic formwork system according to  claims 1  to  4 , characterized in that the separators ( 5 ) alternately have in their central area two appendages ( 8 ) arranged perpendicularly; in that their threaded ends are hollow to receive screws ( 26 ); and in that they have a flat T-shaped configuration in the lower part of the tubular body forming them provided with a notch ( 27 ) suitable for resting on a lower gasket ( 28 ). 
     
     
         6 . Permanent plastic formwork system according to  claims 1  to  5 , characterized in that each of the slats ( 4 ) forming the surfaces ( 1 ) and ( 2 ) of the formwork is secured to the ground by means of U-shaped parts ( 9 ) which are fixed to said ground by means of conventional systems, and inside which there is a threaded rod ( 10 ) which allows adjusting the distance existing between said rod ( 10 ) and one of the walls of the corresponding slat ( 4 ), clamping it and leaving it completely in register. 
     
     
         7 . Permanent plastic formwork system according to  claims 1  to  6 , characterized in that depending on the type of structure to be built, the slats ( 4 ) can have a longitudinally flat configuration for making flat surfaces, or a slightly curved configuration for making curved or cylindrical surfaces. 
     
     
         8 . Permanent plastic formwork system according to  claims 1  to  7 , characterized in that the slats ( 4 ) incorporate, inserted therein between their longitudinal reinforcing partition walls, metal sections ( 13 ) providing rigidity to the slat. 
     
     
         9 . Permanent plastic formwork system according to  claim 1 , characterized in that to build conical coverings, in addition to being able to have a longitudinally flat or curved configuration, the slats ( 4 ) forming the surfaces ( 1 ) and ( 2 ) have an elevated T-shaped configuration in the form of a circular trapezium, having at their lower part reinforcing ribs ( 19 ) and having on one of their sides for their mutual coupling, open sections ( 20 ) engaging in recesses ( 21 ) provided on their opposite side, as well as flanges ( 22 ) in their larger sides, provided with gaps ( 23 ) allowing their coupling on the parallel surfaces ( 1 ) and ( 2 ) forming the tank or structure to be covered, and flanges ( 24 ) overlapping one another fixed to a ring ( 25 ) joining them together. 
     
     
         10 . Permanent plastic formwork system according to  claims 1  to  5  and  8 , characterized in that in an alternative embodiment variant there is provided an inner metal structure, located in the inner part of the inner surface ( 2 ), consisting of a plurality of circular rings ( 29 ), formed by sections of L-shaped flat surfaces, fixed horizontally to vertical posts ( 31 ) every certain space by means of pins ( 30 ), the lower ring ( 29 ) being fixed to the ground by means of a crosspiece ( 32 ), at the T-shaped ends ( 33 ) of which there are coupled four of the aforesaid posts ( 31 ), diametrically opposite two by two, since the latter consist of quadrangular tubes engaging on said T-shaped ends ( 33 ). 
     
     
         11 . Permanent plastic formwork system according to  claim 10 , characterized in that the pins ( 30 ) fixing each ring ( 29 ) to the posts ( 31 ) consist of L-shaped flat surfaces, or angle irons, provided with a bracket ( 34 ) incorporating a hole ( 35 ) suitable for a bolt ( 36 ) or the pin itself, one being located on each side of the post ( 31 ) to join the ends of the sections of ring ( 29 ) thereto. 
     
     
         12 . Permanent plastic formwork system according to  claims 10  and  11 , characterized in that the rings ( 29 ) are provided with holes ( 37 ) suitable for receiving the screws ( 26 ) which will fix the separators ( 5 ), or alternatively the threaded ends ( 6 ) of said separators which will be fixed by means of the corresponding nut ( 7 ), according to the type of separator that is used. 
     
     
         13 . Permanent plastic formwork system according to  claims 1  to  12 , characterized in that the coupling of external reinforcing bands ( 38 ) at the outer part of the slats ( 4 ) forming the outer surface ( 1 ) is provided.