The object of this invention is a concrete slab and a method for manu- facfuring a concrete floor. L concrete slab in accordance with the in- vention can be joined together with other concrete slabs and so they can be used to form a unanimous floor surface. The method according to the invention is a way to form a concrete floor of the concrete slabs according to the invention.

The intention of the invention is to increase the speed of manufacturing concrete floors by increasing the degree of the prefabrication. The in- tention of the invention is also to decrease considerably the costs of manufacturing the concrete floors by rationalizing all the necessary manufacturing steps so that each and every of them can be per- formed in the most favourable conditions. It is known that in the con- struction Industry the prefabrication is always less costly than construct- ing in the construction site whenever it is possible. The usages of the invention are all concrete floors. The larger floor we are talking about the greater advantage is achieved by using the in- vention. As examples of favourable usages of the invention the follow- ing can be mentioned: The floors in industry, sports facilities, entertain- ment, stores, etc. The invention is also suitable for smaller spaces like concrete floors in detached houses.

The concrete floors are made in the known technology by casting on the site. The wet concrete is transferred from the concrete transport lorry upon a tightened sand basis and an insulation layer where there is the iron mounting. The concrete is vibrated tight and the desired layer thickness and the necessary shaping is made with plates and measur- ing. The necessary joints like expansions are made to the casting and the surface is made smooth. It is possible to make patterns in the cast- ing project and the casting is wetted many days after the casting. After wetting and drying the surface of the casting can be rubbed smooth or it can be polished.

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The before described method of making the concrete floors and manufacturing them according to the known technology are pre- sented for instance in Internet in many sites of the companies in the field. The concrete slabs are known to be used to make different kind

10 of constructions like for instance terrace bottoms etc but the high qual- ity concrete floor slab manufacture description material cannot be found anywhere. Therefore, this invention makes possible to create a completely new technique in the market.

15 The greatest drawbacks of the known technologies are that the differ- ent steps of manufacturing a concrete floor - like iron mounting, cast- ing of the concrete, vibrating and the finalizing of the surface - must always be performed at the installation site. There is not such a method in the market where these steps could be moved to the prefabrication.

20 The work performed on the construction site is the worst alternative as far as the costs are concerned but the known technologies do not offer any other competitive alternatives. Actually, it is quite common in the construction industry to make different slab constructions, like cavity slab and bulk slab floors but all the construction on-earth-lying floors are

25 presently made by casting in the site. The hindrance of the develop- ment in this kind of solutions can be seen the thing that it has not been able to create a method to prevent the slabs from moving and dents forming in the joints when the floor is loaded. It is very important that the floor surface keeps completely even all the life time of the floor and

30 this cannot be negotiated in order to save costs. ^" The intention of this invention is to achieve such a concrete slab and a method for manufacturing a concrete floor that drawbacks of the known technology can be avoided. It is characteristic for the solution of the invention what has been presented in the characterizing parts of 5 the claims 1 and 10.

The greatest advantage of the invention in relation to the known tech- nology can be seen its cost effectiveness. The concrete floor according to the invention is manufactured as prefabricates and the concrete 10 slabs that are thus achieved are assembled into a concrete floor in the construction site. The concrete slabs according to the invention can be manufactured completely finished in the prefabrication and be joined together in the construction site in such a way that they remain totally immobile and fixed to each other even during loading. The concrete is floor according to the invention can fill all the same quality require- ments as the traditional concrete floor.

In this document, the term “fongue-and-groove joint” means a joint where two parts fit to each other with a tongue an groove where the 20 joint does not advance following one line or circle through a certain construction that consists of parts.

The invention is described in more detail in the enclosed drawings where

25 fig 1 presents the concrete slab according to the invention in 3D, figs 2a and 2b present the frame of the before mentioned in 3D and cut in the middle (A-A), fig 3 presents two joined concrete slabs according to the invention in 3D, so fig 4 presents the before mentioned slab seen directly from above, fig 5 presents the setting of the fig 4 cut in place B-B, figs 6-8 present the spots C, D and E of the fig 5 zoomed. fig 9 presents a concrete floor that has been manufactured using the method of the invention, figs 10a -10c present one way to join the concrete slabs into each other, fig 11 presents an invention solution that is different from previous ones.

Next there is an explanation of one favourable application structure and details referring to the before mentioned figs.

In the figure 1 there is a concrete slab 100 according to the Invention. It has been prefabricated and it consists of a rectangular frame 10 around it defining its surface area and the iron mounted concrete 20 inside it reaching to the frame. In this example, the first surface of the concrete slab 21 which is its top surface and the second surface 22 that is its bottom surface are both level and they are at the same level as the frame 10 top and botom surfaces. The width a and the length b of the concrete slab 100 can be from under a meter to many meters and these measures can be defined suitably dividable with the total meas- ures of the floor and they can be standardized. The thickness c of the concrete slab can be adapted to each situation, e.g. taking into ac- count the coming load of the floor, or even it can be standardized.

In the figure 2a there has been shown the frame in 3D and in the figure 2b its cut in the previous figure in point A- A. So the frame 10 defines the width a of the concrete slab, its length b and in this example also its thickness c. The mentioned frame consists of the first, the second, the third and the fourth side 1 -4 that have the whole length of the side the shape of certain profile plates. The mentioned sides form the frame around P and they have been joined together by the way that has been indicated in The figure: The comer Joints of the frame are tight so that the inside them casfed concrete remains inside the frame. In the mentioned sides, inside of them, there have been fixed anchors 5 to fasten the frame to the concrete to be casted inside the frame.

In the figure 3 there has been presented in 3D two joined concrete

5 slabs 100, in the figure 4 this has been presented directly from above and in the figure 5 the lengthwise cut B-B of this combination. The pro- files y of the first and the second sides 1 , 2 are identical and the profiles z of the third and the fourth sides are identical. In this example, the down parts of the profiles y form the first tongues 100.1 to the concrete

10 slab 100 and the upper parts of the profiles z form the second tongues 100.2 to the concrete slab. So in this example, the first and the second side 1, 2 of the concrete slab 100 have the shape of the profile y and they have the mentioned first tongues and the third and the fourth sides 3,4 have the shape of the profile z and they have the mentioned

15 second tongues.

The figure 6 is the point C of the cut B-B and it presents in more detail the profile y of the first and the second sides 1, 2. The figure 7 is the point D of the cut B-B and if presents the profile z of the third and the

20 fourth sides 3, 4. The figure 8 is the point E of the cut B-B and it presents how the profiles y and z fit together how the Slabs 100 can be joined together using the tongue-and-groove joint J. When in the installation procedure the tongue 100.2 of the third and the fourth side 3, 4 of the next concrete slab 100 is slid or pressed upon the tongue 100.1 of the

25 first and the second side 1, 2 of in the installation procedure previous concrete slab 100 so that the profiles y and z join so that the flexible lock organ 7 is bent and gets pressed closer to the profile z and as the profiles y and z of the tongue-and-groove joint j jump back into origi- nal position and get inserted into the groove of the in the installation

30 procedure previous concrete slab 100 down part groove 8 so that the head 7.1 of the lock organ (shown in figure 7) comes against the sur- face 8.1 of the groove (shown in figure 6} or near it. In this example, the angle a between the surface 8.1 and the second surface 22 of the concrete slab is same as the bottoms of the opposite lock profiles 6a and 6b grooves and the fop surfaces n of the tongues and the angle (3 of the tongues and the first and the second surface 21, 22 of the con- Crete slab. The surfaces m, n and q are in this example flat. The men- tioned lock profiles form the lock 8 that prevents the longwise move- ment X of the concrete slabs and the lock organ 7 prevents their movement up and down Y. The locking between the concrete slabs 100 according ^" to the invention can also be made in some other way than what has Just been pre- sented. If is essential for the invention that the lock 6 and the lock organ 7 or other ways to achieve the corresponding functions prevent the longwise movement X of concrete slabs 100 and the vertical move- ment Y. :

The figure 9 presents a concrete floor 200 made of the concrete slabs 100 according to the invention. The manufacture of this example of the invention floor works so that the concrete slabs 100 are manufactured in the prefabrication in the way that has been told before and the concrete floor is comprised as follows; Upon the basis 80, like sand that has been smoothened and tightened, the guide organs 51 are installed taking into account the measures L of the slabs where the distance S is less than L. The concrete slabs 100 are placed against the upper sur- faces 51.1 of the guide organs and thus these surfaces define the lines of the first and second surfaces 21, 22 and a sufficient height H of the guide organs ensure that the concrete slab does not touch the basis 50 between the guide organs and that there will be sufficiently space for the insulation between the basis 50 and the concrete slabs 100. The concrete slabs 100 alongside and after each other are fixed and locked to each other using locks 6 and lock organs 7. When the con- crete floor 200 surface is completed the spaces 52 between the basis 50, guide organs 51 and the concrete slabs are filled with the filer 53. As an example of the guide organs 51, certain thick plates can be mentioned like for instance polyurethane plates and the 53 filler for ex- ample polyurethane foam.

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The figures 10a -10c present the way of Joining the profiles y, z and the operation of the lock organ 7 when assembling the concrete floor ac- cording to the invention. The surfaces of each bottom m of the groove of the lock profile 6a, 6b and the surface q connecting the surface n of 10 the tongue has been set into such an angle 5 in relation to the first and the second head 100.3, 100.4 of the concrete slab that the lock organ 7 is able to flexibly get into the final position of the figures in the groove 8. In this example the heads 100.3, 100.4 are vertical and the angle 5 is 20°. The value of the mentioned angle is determined by the other 15 characteristics of the concrete slab and as an advantageous angle value 5 can be considered the values 10°-45°.

The guide organs 51 are installed in such a way that they support the !ongue-artd-groove joints at least The time of the installation. They can be placed under the mentioned Joints or between them. The concrete slabs 100 and the tongue-and-groove joints J between them of the fin- ished concrete floor 200 according to the invention are all over sup- ported from below so that the locations of the guide organs 51 do not have great importance.

The frames and their sides 1 - 4 that fit together and lock to each other in pairs like in this example 1 and 3, 1 and 4, 2 and 3, 2 and 4 can be made and formed in many different ways but it is essential for them from the point of view of the invention that they can Join tightly and o lock the joint of the next to be installed concrete slab 100 according to the invention to the previously installed concrete slab 100 according to the invention and the locking should be such that the mentioned con- Crete slabs cannot move in relation to each other. The most favourable shape of the frame is essentially rectangular, that is square or rectangle but polygon shapes are not excluded outside this invention even though their cost effectiveness is lower than rectangular ones.

Fitting tight together the profiles y, z consists also the application where the shapes of the mentioned profiles have a certain installation toler- ance that enables their favourable installation. The movements be- tween the concrete slabs 100 allowed by the tolerances are not the mentioned lengthwise or vertical movements X, Y,

The profiles y and z can be made in many ways within the idea of the invention. The most favourable way from the point of the strength is to have the tongues 100.1, 100.2 of the same height and the bottoms of the grooves of the lock profiles 6a, 6b and the surfaces m, n of the tongues that are of the same direction in this example and form with the first or the second surface 21 , 22 of the concrete slab an angle b of over 0° but also some similar applications can in some invention solu- tions come into question. It is favourable for the invention that the an- gles a and (β are similar but this invention is not limited to only this kind of situation.

Assembling the sides 1 -4 to a frame 10 requires the working of all the ends so that the frame comers will be tight. The sides 1 -4 each can be made of one or more parts. From the point of view of the invention, the most favourable way is to make them of one piece for instance in a plate workshop or with a plate work machine. The working of the men- tioned frame 10 in the comers can be made in many ways. One fa- vourable way is to cut the unfinished work ends ready so that after the folding the ends have the right shape. Another way is to cut the shape after folding. Also all the other ways that give a favourable end result for tfie invention are OK. Alternatively, the frames can be left not tight- ened in the corners and fake care of the tightening with moulds for the casting of the concrete.

The concrete slab 100 can be very large and the max size is deter- mined by the available transport options. The thickness of the concrete slab can be any practical thickness. As an example of the width a can be mentioned 3 m, length to 6 m and thickness c 100 mm. When trans- porting the concrete slabs 100 any suitable known method can be used.

The figure 11 presents a concrete slab 100 according to the invention that has a round P a regular hexagon. Also other polygons that have an even amount of sides 1- n belong to the scope of the invention. In these cases it is essential that half of the sides side by side of the round P have the profile y and the rest the profile z.

The inclinations in the surface of the concrete floor can be made in the prefabrication phase to the surfaces of the concrete slabs 100. In this case, one inclination can possibly reach all extend of the first surface 21 of the concrete slab or the mentioned surface can include at least two different directions surface parts. The inclinations can in some cases be made when making or installing the basis 50 or guide organs 51.

One invention application option is a concrete slab 100 that is at least in some part thicker than the frame 10. In this case, the edges of the concrete slab that are thicker can be moulded. On the other hand, when a concrete slab has inclinations the heights of the sides 1 -4 can be adapted according to the surface of the concrete 20.

One application option of the invention is to install the first tongues second surfaces 22 of the slabs are their top surfaces and for the sur- face 201 of the floor.

The material of the frames and the anchors can be any suitable mate- rial. As a favourable example of this kind of material is iron that has al- most the same heat expansion coefficient as the concrete. One mate- rial that has been found to be good for the frame 10 is iron plate PL 1.5. All the other favourable side 1 -4 thicknesses are OK for the invention. The anchors 5 can be shaped and fixed to the frame 10 in many ways. It is essential that they are able to connect the concrete 20 to the frame 10 sufficiently well.

The visible surface of the concrete 20 can be completely finalized in the prefabrication in a desired way. Patterning, rubbing, polishing etc. can be performed before installing the concrete slabs 100 to their places. Treating the dried concrete 20 after the installation of the concrete floor 200 according to the invention is not excluded outside the application of the invention.

It is possible to make lead-ins and/or cuts to the concrete slab accord- ing to the invention already during its manufacture.

It should be noted that even though this explanation sticks to only one for the invention favourable application example this does not by any means want to limit the usage of the invention to be used only in this kind of applications but many variations are possible in the scope of the invention idea defined in the claims.