This invention relates to a method for joining successive building or construction blocks, which comprise two plane major faces and four edge races, which construction blocks being joined along an ease race or each block, abutting each other, by means of a profile comprising web ad flanges. The invention also relates to a profile for carrying out the method, as well as a construction block to be joined in accordance with the method.
 A previously known method and a sheet profile of the kind mentioned above are described in the dissertation paper No. 268, Faculty of Building Technology, the Royal Swedish Institute of Technology. The invention is directed towards improvements of the prior art in order to reduce the number of profiles for joining construction blocks and obtain higher security of the supporting function against the combination or longitudinal and lateral forces. In spite of smaller sheet faces the new method and sheet profile also provide good strength when a load is applied to the composite construction in the longitudinal direction of the sheet profile. Further, the assembly is facilitated on the construction site.
 The invention providing the improvements stated above has the characterising features stated in the appended patent claims: the method according to patent claim 1, the sheet profile according to claim 4 and the construction block according to claim 9.
 An embodiment of the invention as well as variations thereof will be described below with reference to the accompanying drawings.
 FIG. 1 shows a schematic perspective view or construction blocks, which are joined according to a prior art method.
 FIG. 2 shows a schematic perspective view of two construction blocks, which are joined according to the invention.
 FIG. 3 shows a perspective view of the new sheet profile.
 FIG. 4 shows a cross-section through two construction blocks, which are joined by the according to the invention.
 FIG. 5 shows a modification of a step of joining two construction blocks by the profile according to the invention.
 Accordingly, FIG. 1 shows two construction blocks, e.g. of expanded plastic, which are joined according to a prior art method. The construction blocks 1 and 2 are arranged so that each block has an edge face abutting an edge face of the other block along the broken line 3. A major face 4 and 41 of each of the construction blocks 1 and 2, respectively, is shown. Over the broken line 3 on the major faces a U-shaped beam 3′ has been placed, the flanges 6 and 6′ of which have been pushed into slots in the major faces of the construction blocks 4 and 4′, respectively. On the opposite major faces a corresponding U-shaped beam has been inserted. Thus, by means of the two U-shaped beams the two construction blocks 1 and 2 are mechanically joined so that it is not possible to pull them away from each other. The joint of the two construction blocks can be improved by gluing the webs of the U-shaped profiles against the major faces. This is prior art.
 In FIG. 2 the method according to the invention is shown. As before the two construction blocks 4 and 5 are placed against each other along the broken line 3, thus having two opposite edge faces close to each other. Between the edge faces the web 7 of a sheet profile 8 is now positioned. This sheet profile 8 has an approximately Z-shaped cross-section. A flange 9, extending to the left in this figure from a longitudinal edge of the web 7, is abutting the major face 5. At its free edge the flange is bent inwards into the construction block, so that a flap 10 is formed. This flap engages a slot in the major side 5 in the block 2. From the opposite longitudinal edge of the web 7 a flange 11 is extending, which abuts the rear major face of the block 1 in accordance with FIG. 2. This flange 11 also has a bent flap 12, which is positioned in a slot in the rear major race or the block 1. Thereby the two blocks are joined by means of the sheet profile, but it is possible that the blocks turn with respect to each other. Normally, however, the blocks are erected with the sheet profile standing upright, when the walls of a building are erected, and then,the blocks are supported by their bottom faces in a U-shaped profile, or the like. The blocks can be further stabilised either by means of gluing the edge faces against the web 7 of the sheet profile, or by means of some kind of screw joints arranged in such a manner, that screws extend obliquely through the blocks from one major face and into the web of the sheet profile.
 In FIG. 3 there now is shown a perspective view of the sheet profile according to the invention. It is evident that the web 7 has the two flanges 9 and 11, respectively, which extend from the web at an angle of 90° and in opposite directions from the respective edge of the web. each flange has its end edge bent in such a manner that a longitudinal flap 10 and 12, respectively, is formed. It is the two flats 10 and 12, which are inserted into slots that initially have been made in the major faces of the blocks. The dimensions of the sheet profile are preferably such that the height of the web corresponds to twice the thickness of the respective block, and the length of the web corresponds to the length and the edge face of the block, i.e. normally the height of the construction block when it forms a wail in a building. The width of the flanges 3 and 11 is approximately half of the height of the web, and the extension of the flaps down into the constructions blocks is approximately one third of the height of the web. The values stated above are contemplated guideline values.
 To reduce the thermal conduction transverse the longitudinal extension of the web triangular apertures 13 can be made. These may be arranged in such a manner, that they are positioned in zigzag, so that straight lines of material from one edge of the profile to the other edge are interrupted.
 FIG. 4 shows a cross section through the joint area between two construction blocks 1 and 2. This picture shows more clearly the slots, which are arranged in the major faces of the construction blocks for the insertion of the flaps 10 and 12, respectively. The broken line 14 illustrates schematically how a screw joint can be arranged to enhance the connection between the blocks, e.g. in case the construction blocks are positioned in a horizontal plane and e.g. form a ceiling in a building.
 In FIG. 5 two construction blocks are shown in separated positions just before they will be brought together. In the construction block 1 the incision 15 is shown, into which the flap 10 shall be inserted. The bottom side of the construction blocks is covered with a cover plate 16, which, in the right end of the figure, covers the sheet profile 8, which already has been fitted there, but leaves the major face free in that area, where the flap 10 of the other sheet profile will be inserted. Thus the cover plate 16 extends as far as to the incision 15.
 On the top face of the block 1 there is a flexible cover plate 17 making a weld joint possible. In its right end in the figure it covers the flange 11 of the sheet profile and extends a certain distance beyond the major face, so that when the blocks are brought together it will cover the web of the sheet profile on the adjacent block. In this way a very tight building construction is obtained, which also as stable and easily processed to give the construction a good surface finish.
 Within the scope or the invention in particular the sheet profile may be varied. Accordingly it is possible to modify the mechanical design of the sheet profile, which provides the anchorage of the flanges in the major faces of the construction blocks. In the figures there has been shown a longitudinal flat 10 and 12, respectively, extending along the entire length of the sheet profile. It is possible not to have a flap with that total extension, but as an alternative to a flap, wedge shaped tips or the like may be bent down or provided, or smaller flaps. It is also possible to punch projections in the flanges, e.g. having triangular shape, which protrude down into the major faces of the construction blocks. The functionally important feature is that there is some kind of mechanical coupling between the flanges and the major faces of the construction blocks, so that tensile stresses may be absorbed between two blocks from each other. In other words, the sheet profile shall be anchored against the edge face of the construction block by means of its flange. The construction blocks may be made of another material than plastic, e.g. lightweight concrete or other substance. Further, the sheet profile may be a composite profile, e.g. where the web is made or some kind or fibre board whereas the flanges are made of sheet metal and secured to the web by means of some kind of joint.