GB2152966A - Building block - Google Patents

Abstract

A building block, open at one end, comprises an end wall (3) connecting a pair of parallel concete side walls (2) at the other end, and a central heat insulating partition (1) of cellular plastics extending from end to end through the block. The partition (1) is secured to the side walls (2) by means of ribs (4) which are integral with the side walls and are connected to the partition by dovetail joints, and is secured in the end wall (3) by means of half dovetail joints. The ribs (4) and the portions of the end wall (3) on opposite sides of the partition have lateral extensions which abut the partition (1) adjacent the dovetail joints. Cavities (5, 6,7 Figure 2) are formed inside the block on opposite sides of the insulating partition (1), one wall of each cavity being defined by the partition. <IMAGE>

Description

SPECIFICATION Building block This invention relates to concrete building blocks of the cavity type having a heat insulating material of cellular plastics extending inside the block throughout its whole length and parallel to the side walls of the block.

The use of cast concrete in building is known.

The concrete form work required and the related work and facilities are almost entirely disposable.

The concrete form work is extremely costly, consuming a lot of time and requiring highly-paid carpentry. Furthermore, the timber needed for this kind of work and the handling thereof causes great disorder and security risks on site, particularly the timber which is broken off the form work. Also, installation of heat insulation in such concrete constructions and the fixing thereof securely in place is difficult, and in winter it is sometimes necessary to heat the concrete moulds so as to enable casting to be effected. This is difficult, requires a lot of energy and special equipment, and is often uneconomic, particularly for private builders.

It is also known to use pre-cast building blocks in basements, outer walls and various other constructions, therefore avoiding many disadvantages of using conventional cast concrete form work.

Building blocks can be roughly divided into two types, solid blocks and cavity blocks, and it is known to provide both types with heat insulation material fitted inside the block to serve as a thermal conduction barrier.

Basement blocks used for foundation work are one example of solid blocks, the bottom surfaces of which may be provided with installation and locating grooves.

Solid masonry blocks which are provided with separate insulating elements of cellular plastics material are also commercially available. One disadvantage of this type of block is that the blocks have to be masoned, masonry and related work being expensive. Also, vertical reinforcement of such a block construction is difficult, cutting of the blocks as well as the after-treatment in general calling for a lot of work. In addition, there are restrictions on the use of this kind of block in loadbearing or unequally loaded constructions or in constructions otherwise requiring high strength properties.

Finnish Patents Nos. 44,042; 46,761; 47,686 and 60,276 disclose blocks of the cavity type which can be easily connected in sequence and which are provided with cavities for grouting, vertical reinforcement, cable entries, etc. For example, Finnish Patent No. 60,276 discloses a block in which one end is formed with an open cavity, the side walls are connected by means of intermediate walls, and the top surface is downwardly arched for levelling of the grouting and for ensuring that the grouting extends continuously from one block to another.

These blocks are heavy in construction and difficult to be after-treated. Insulating material is added afterwards into the cavities, and fixing of the material in place is difficult.

German Offenlegungsschrifts Nos. 1 803 565; 1 916 400; 1 924 612; 2 924579 and 3 035 312 disclose cavity blocks which are provided with a separate insulating element of cellular plastics for forming a thermal conduction barrier.

For example, German Offenlegunsschrift No. 3 035 312 discloses a cavity block provided with cavities for grouting, and a heat insulating material extending throughout the whole block from end to end parallel to the side walls of the block, the insulation being fastened to the concrete frame of the block by means of dovetail joints. All sides of the cavities of the block are defined by the concrete frame, and the block construction thus becomes heavy and causes high costs.

German Offenlegungsschrift No. 1 924 612 discloses a block construction in which a separate heat insulation element similarly extends throughout the block. However, the fixing of the insulation is not sufficiently secure, and one side of the insulation is essentially defined by the concrete construction.

German Offenlegungsschrift No. 1 803 565 discloses a cavity block element in which the longitudinal sides of the insulation are essentially defined by the external and internal wall constructions.

Economically, this construction will not achieve the best possible end result, and besides, the construction is relatively heavy.

German Offenlegungsschrift No. 2 924 579 discloses a building element in which the sound and heat insulation is defined by the cavity channel and a separate backward ventilation channel. The fastening of the insulation is not separately sufficiently secure.

The object of the present invention is to provide a building block of the cavity type having heat insulating material forming a thermal conduction barrier providing good heat insulating properties, particularly a block for use in constructing footings and external walls, which avoids the above disadvantages and difficulties and which, in particular is light and can be handled manually.

With this aim, according to the invention we provide a building block which comprise a pair of parallel, relatively thin, concrete side walls, and which is open at one end and closed at the other by an end wall connected to the side walls, the block having a heat insulating partition made of cellular plastics material extending centrally throughout the length of the block parallel to the side walls and spaced therefrom by ribs connected to the side walls and to the partition so that the partition, the ribs, and the walls of the block define cavities within the block on both sides of the heat insulating partition.

The building block in accordance with the invention thus has cavities, preferably of equal size, on opposite sides of the insulation by virtue of the fact that the heat insulating partition is positioned through the middle of the block and is supported by the side walls through the separate ribs. The cavities are thereby defined by the heat insulation on both sides of the mid line parallel to the side walls of the block.

The ribs, which may be formed integrally with the side walls, are preferably connected to the central heat insulating partition by dovetail joints, each rib preferably comprising a dovetail portion received in a corresponding groove in the partition, and a lateral extension portion abutting the partition on each side of the groove, thereby decreasing and levelling the forces exerted on the dovetail joints during the grouting phase.

The central insulating partition is preferably fixed to the portions of the end wall on opposite sides of the partition by means of half dovetail joints, each portion of the end wall preferably comprising a half dovetail portion received in a corresponding groove in the partition, and a lateral extension portion abutting the partition adjacent the groove.

An advantageous construction of the block in accordance with the invention is symmetrical with respect to the central axis parallel to the side walls.

A secure fixing of the insulation in the block is achieved by means of the dovetail joints with the ribs and the half dovetail joints with the end wall portions, and the lateral abutment portions of the ribs and the end wall portions. In addition, the use of a central concrete wall inside the block is avoided because the insulating partition serves as one wall of the cavities, whereby the resulting block is light and also easy to be after-treated. The symmetry of the cavity construction with respect to the central insulation contributes to an even grouting and decreases the strains exerted on the central insulation when the grouting sets.

An example of a building block in accordance with the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the block; Figure 2 is a top plan view of the block; Figure 3 is an enlarged view of a part of Figure 2; Figure 4 is an enlarged view of another part of Figure 2; Figure 5 is a perspective view of part of a modified form of the block shown in Figures 1 to 4; and Figure 6 is a top plan view of a corner block for use with blocks in accordance with the invention.

Figure 1 illustrates a cavity block in accordance with the invention comprising a central insulating partition 1 of cellular plastics material. As shown in Figures 1 and 2, the block comprises parallel side walls 2 of concrete, and an end wall 3 connecting the side walls at one end and consisting of concrete wall portions and a portion of the central insulating partition 1. The central partition 1 of cellular plastics is connected to the side walls 2 by means of ribs 4 which are preferably cast integrally with the side walls, the central partition 1 being secured to each rib by means of a dovetail joint formed by a dovetail portion provided on the rib and received in a corresponding dovetail groove in the partition.

Cavities 5 and 6, as well as open end cavities 7, are thus formed inside the block symmetrically on opposite sides of a mid line A through the central partition 1 parallel to the side walls 2, the cavities being defined by the walls 2 and 3, the ribs 4 and the insulating partition of cellular plastics.

Figure 3 separately illustrates the rib construction of the block, comprising a wall portion 8, a resilient lateral extension portion 9 for reducing strains exerted on the dovetail joint with the central partition 1, and a dovetail portion 10. The arched outer surface of the lateral extension portion 9 enables the grouting strains to be levelled, the principle being to avoid sharp corners.

Figure 4 illustrates the fastening of the insulating partition 1 to the concrete portions of the end wall 3 by means of half dovetail joints. Each end wall portion is provided with a half dovetail portion 11 received in a corresponding groove in the partition 1, and a lateral extension 12 extending inwardly in the block adjacent the side of the partition 1 for levelling strains, Figure 5 illustrates a construction in which recesses 13 are provided for levelling grouting inside the block and enabling adjacent blocks to be joined together by means of a integral cast. The recesses 13 are provided on the upper surfaces of both the ribs and the end wall 3 on both sides of the central insulation 1.

Figure 6 illustrates a corner block to be connected with basic blocks in accordance with the invention. The corner block is identical to the basic block with respect to construction and dimensions except that the central insulating partition 1 does not extend up to and into the end wall, but executes a right angled bend near the end wall to form a relatively short portion 14 of insulation extending to and dividing one of the side walls. This portion 14 of the insulating partition is fastened to the side wall by means of half dovetail joints similar to that shown in Figure 4, and ensures that a building can be constructed with the blocks so that the insulating material forms a continuous thermal conduction barrier around the corners as well as along the walls. The insulation portions 1 and 14 are made of cellular plastics, and the rest of the block construction, including the ribs, is of concrete.

In connection with grouting of the block in accordance with the invention, the cast pressure resistance thereof has proved to meet the desired standard, so that a cast pressure of half a room height of 1200-1400 mm can be used completely reliably. The blocks in accordance with the invention can be manufactured by means of conventional concrete mixing machines and suitable moulds. For example, a suitable machine which could be used is an electrohydraulic concrete producing machine (model MECA TK-120-1) manufactured by Mecakone OY of Joensuu, Finland.

Claims (9)

1. A building block which comprises a pair of parallel, relatively thin, concrete side walls, and which is open at one end and closed at the other by an end wall connected to the side walls, the block having a heat insulating partition made of cellular plastics material extending centrally throughout the length of the block parallel to the side walls and spaced therefrom by ribs connected to the side walls and the partition so that the partition, the ribs, and the walls of the block define cavities within the block on both sides of the heat insulating partition.

2. A building block according to Claim 1, in which the ribs are integral with the side walls.

3. A building block according to Claim 1 or Claim 2, in which the ribs are connected to the central heat insulating partition by dovetail joints.

4. A building block according to Claim 3, in which each rib comprises a dovetail portion received in a corresponding groove in the partition, and a lateral extension portion abutting the partition on each side of the groove.

5. A building block according to any one of the preceding Claims, in which the portions of the end wall on opposite sides of the partition are connected to the partition by half dovetail joints.

6. A building block according to Claim 5, in which each portion of the end wall comprises a half dovetail portion received in a corresponding groove in the partition, and a lateral extension portion abutting the partition adjacent the groove.

7. A building block according to any one of the preceding Claims, in which recesses are provided on the top surfaces of the end wall and the ribs between the partition and the side walls.

8. A building block according to Claim 1, substantially as described with reference to Figures 1 to 4, or as modified with reference to Figure 5 of the accompanying drawings.

9. A building block substantially as described and shown in Figure 6 of the accompanying drawings.