The invention relates to prefabricated composite reinforcement surfaces.

In the area of construction of shell structures, the prior art refers to reinforcement, which is either fabricated at the position of the construction of the shell or it is prefabricated and it is positioned on a discrete framework.Then plasters or concretes in fluid are applied on it. According to another method, prefabricated parts of the final surface of the shell are fixed on cables or other load bearing elements. It is also known to use metallic perforated sheets, fixing them on load bearing surfaces, and then to apply plasters or coatings. Such sheets cannot be considered as reinforcement, because the plasters are applied only on one of their sides. Further plasters of high liquidity escape from the existing perforations.

European patent application EP-A-0424306 discloses a prefabricated composite reinforcement surface comprising a main reinforcement made of rods of non-rusting material, a surface of secondary reinforcement and a plane barrier, which cannot be penetrated by plasters. In the case shown on fig. 7 of the above mentioned application the barrier is attached to the rods of the main reinforcement and the attachment is continuous along the whole length of the rods. The surface is plane and after its suspension from the load bearing elements of a structure, the side of the barrier adjacent to the reinforcement is covered with plasters. The reinforcement is appropriate to give the required strength to the plane, suspended shell.

An object of the present invention is to propose prefabricated composite reinforcement surfaces, whioh are at the same time frameworks for the construction of non plane shells.

According to claim 1 the prefabricated composite reinforcement surface comprises a main reinforcement made of rods of non-rusting material, a surface of secondary reinforcement and a plane barrier, which cannot be penetrated by plasters, whereby the main reinforcement and the surface of secondary reinforcement are made of flexible material, and the barrier is attached to the surface of secondary reinforcement

and the rods of the main reinforcement are free, or/and the barrier is connected to the main reinforcement, whereby the rods of the main reinforcement are connected to the barrier at discrete points, so that the rods between the discrete points are free. In contrast to the way of attachment described in EP-A-0424306, whereby the rods of the main reinforcement are attached on the barrier along their whole length, the attachment of the barrier to the surface of secondary reinforcement or/and to the main reinforcement according to claim 1 , enables the rods of the main reinforcement to be surrounded by the plasters or concretes so that the shell to be constructed has the required strength and the reinforcement is protected from the influence of the environment.This way of attachment allows also the barrier to follow the curvature of the main reinforcement and the surface of secondary reinforcement, without risking to be damaged, during the bending or/and the folding of the prefabricated composite reinforcement surface, when the latter is placed on guides for the construction of non- plane shells.

A main advantage of the present invention is that there is no need to build a framework and consequently the cost of the construction of the reinforced shells is low. The prefabricated composite reinforcement surfaces may replace in almost all cases material having high cost and contribute to a substantial saving as a result of the decrease of the volume and mass of the materials and of the labor costs.

Claims 2 - 11 comprise further features offering other advantages.

A way of carrying out the invention is described below with reference to the following drawings, which show only an embodiment of the invention:

fig. 1 shows a prefabricated composite reinforcement surface according to the invention, figs. 1a and 1b show this surface in its final positions and fig. 1c presents the surface of fig. 1 , with parts of successive layers, from which it is constructed, being deleted. fig 2 - 8 show the various layers of the surface of fig. 1. fig 9 shows the attachment of the barrier to the secondary reinforcement of the surface of fig. 1.

figs. 10 - 18 show various uses of the surfaces according to fig. 1.

Figures 2, 3, 5, 8 show the layers of the main and non-rusting metal reinforcement, each of the layers being constructed by rods 51 to 54 having different orientation. The function of this reinforcement is to bear the loads applied to the finally constructed shell, and to transfer them to the suspension or/and fixing points of the prefabricated composite reinforcement surfaces. The number of the layers as well as the quality the relative position and the orientation of the rods of each layer depend on the use of the surfaces.

Figures 4 and 7 present two surfaces 2 of the secondary reinforcement made of non-rusting metallic material, whose function is the reinforcement of the finally constructed shell and the transfer of its loads to the main reinforcement. As in the case of the main reinforcement the number of the surfaces as well as their configuration depend on their use.

Figure 6 presents the barrier 3 formed by a thin membrane sheet. Its main function is to prevent plasters and concretes, which are blown to it, to escape from the openings of the reinforcements.lt is as thin and flexible as required by the use. It is made of material allowing the plasters to be effectively adhered on it. It is also easily cut by a cutting tool or a heated, sharp tool, evaporates when under a hot stream of air or it can be easily pulled away from the surface of the finally constructed shell, so that if plasters or concretes are to be applied to both sides of the prefabricated composite reinforcement surface, the two layers of the applied material would be effectively bonded to each other.

Figure 1 shows the prefabricated composite reinforcement surface 10 with the main reinforcement, the secondary reinforcement and the barrier attached to each other, whereby the surfaces of secondary reinforcement are trapped between the layers of the main reinforcement, and figure 1c shows the prefabricated composite reinforcement surfaces of figure 1 , whereby parts of successive layers, from which it is constructed have been deleted. The barrier 3 is attached to discrete points of the surface of secondary reinforcement 2. This attachment, which is shown in fig. 7,

where the points of attachment are designated with 7, offers substantial advantages, because it allows the plasters and concretes to totally surround the surface of secondary reinforcement and the rods of the main reinforcement, during their application. The shell so constructed has the required strength and its reinforcement is effectively protected from the influence of the environment. According to another way of attachment of the barrier and the composite reinforcement, which offers similar advantages, the barrier 3 is attached to discrete points of the rods 51 or 52 or 53 or 54 of the main reinforcement, so that the rods between the points of attachment are free.The dimensions of the surface 10 vary according to the use , and the surface can be easily fastened to similar surfaces for the construction of various geometrical configurations.The surface has the flexibility allowing it to be bent and to be folded, during its fixation on guides for the construction of non-plane shells as shown in figures 1a and 1b. It is made from material, which can be cut with normal tools, so that it can de adjusted to the geometrical requirements of the construction. If required, additional reinforcement can be added to the surface, after its location in its final position. Because of the presence of the barrier 3, the prefabricated composite reinforcement surface does not allow plasters and concretes to penetrate it during their application, so that it functions as a framework. After the application of a first layer of plaster or concretes having minimal thickness - a few mm -, to one side, and the subsequent solidification of this layer, the surface 10 becomes a rigid and strong, suspended or supported shell, which can receive from either side subsequent layers of plasters or concretes having greater thickness. If the subsequent layer is to be applied to the side of the surface, which is not covered by the first layer, main or secondary reinforcement is provided to either side of the barrier and the barrier is removed after the initially applied layer is solidified. In other words after the application of the first layer and the construction of the shell, the shell also functions as a framework, which can receive heavier layers of plasters or concretes.

A prefabricated composite reinforcement surface can be used in many application as described below.

In cases of construction of waterproof shells, such as the hull of ships (see figure 10), barges, or buoys, or in the construction of floating piers (see figure 11), the

prefabricated composite reinforcement surface substitutes more expensive materials, such as wood, steel sheets, or other synthetic materials, which are used in our days for offshore and naval constructions. In the process of the construction, the surfaces are attached to the frame of the construction and then plasters or/and concretes of appropriate requirements are applied on them to form a shell having the required strength. The process continues with the polishing and the painting of the solid, thin shell. If layers of plasters or concretes are to be applied to both sides of the prefabricated composite reinforcement surface, the barrier is removed and plasters or concretes are applied on the existing main or secondary reinforcement. The configuration of the main and secondary reinforcement is selected according to the strength requirements of the offshore or naval construction, which in its turn depends on the draught.

In the cases of construction of a tween leaf shell with a gap of air between the two leafs, the prefabricated composite reinforcement surfaces are placed on appropriate blocks or on ribs of the frame, projecting from the shell first constructed, which forms the one leaf of the two leaf construction. Then plasters or concretes are applied. The depth of the blocks or the projecting ribs equals the thickness of the air gap.

Another use of the claimed surfaces is for the construction of shells, which are either suspended from cables (see figure 12), or supported, such as a dome (figure 13). In this case the cables can be replaced by simple metallic guides, depending on the weight and dimensions of the final construction.

The surfaces according to claim 1 are also used for the construction of tubular and cylindrical shells. For such a construction, they are placed on ribs or guides. If needed further reinforcement is added, and the plasters or concretes are applied, to form the walls of tanks, as shown in figure 18, draining ducts (see figure 14), air or smoke ducts with single or multiple shells. It should be noted, that also in this case the shells are constructed at their final position, and that there is no need to use frameworks.

For the construction of walls of surface or deep tunnels, such as the one shown in figure 15, the surfaces of prefabricated reinforcement are fastened to the inner or

outer side of the reinforcement grids of the already existing walls. Subsequently concretes are casted between the surfaces and the existing walls, from bores, which are formed on the latter.

The surfaces according to the invention are further used for the construction of protection barriers. During the impact the shells are subjected. to elastic fracture, whereas the rods of the reinforcement, which are fixed to appropriate bars having a certain distance among themselves, function as elastic strings absorbing energy.

The surfaces can be also used for the construction of walls and floors of interior spaces (see figure 16). The surfaces are placed on supports positioned on the surfaces to be covered, and the plasters or concretes are applied on them.

The construction of perpendicular planes, corrugated shells, partitions of interior spaces, single and tween leaf walls, as the one shown in figure 17, is carried out by suspending the surfaces from the ceiling, fastening them to the floor, and applying plasters to one or both sides.

The above description is only way of carrying out the invention and does not limit it. Modifications and changes are possible within the scope of the invention, as defined in the claims which follow.