EP0528753B1 - Building block with improved heat insulation - Google Patents

Abstract

Large-format building block with improved heat insulation. The block contains inside it a number of continuous vertical cavities (1), which have the shape of two trapezoidal prisms pushed together at their minor faces. The cavities are arranged in rows parallel to the end faces (A,B) of the block, and offset by half their length with respect to one another in every two adjacent rows. As a result, the heat conduction along the webs between the cavities is compelled to follow an extended zig-zag path, whereby the heat insulation is correspondingly improved. In addition, the block contains along two mutually perpendicular half centre planes (E,F) preformed predetermined breaking points (7), such that a quarter of the block can be detached by the blow of a hammer and used with the rest of the block for forming corners and lintels. <IMAGE>

Description

The invention relates to a brick according to the preamble of claim 1 and the use of such brick for creating masonry.

A general requirement when creating masonry is to use as large as possible masonry blocks, so-called block stones, in order to reduce the amount of work involved in erecting the masonry. Block stones also have the further advantage that they require a smaller number of mortar joints than small bricks, which improves the thermal insulation of the masonry. However, there are certain limits to this tendency, on the one hand due to the weight of the blocks to be moved, which must be adapted to the physical strength of the mason, and on the other hand due to the need to rationalize complex structures with corners, gradations and lintels, i.e. without using different ones Formats of bricks to be able to execute.

Another requirement when creating such masonry is good thermal insulation properties of the bricks. Compared to other materials such as natural stone or concrete, bricks or bricks made of fired clay, with and without additives, have a relatively poor thermal conductivity per se and result in good thermal insulation. It has also been known and customary for a long time to further improve this thermal insulation by installing cavities and at the same time to reduce the weight of the brick. For reasons of pressure resistance and efficient production, brick is preferred which is completely interspersed with cavities and therefore also has fully continuous webs.

The compressive strength of a brick penetrated by vertical cavities is highest in the longitudinal direction of the cavities. Since the pressure load on masonry is normally the greatest in the vertical direction, it is therefore logical to design or orient the masonry so that the continuous cavities lie in the vertical direction. Such bricks are called perforated stones.

In the directions transverse to the continuous cavities and webs, the pressure resistance of the bricks is reduced for obvious reasons. The thermal insulation capacity of the bricks is increased in these directions. The heat conduction in a perforated brick is largely via the webs between the cavities; the cavities between the webs essentially act as a heat barrier or insulation.

The compressive strength of a hollow hole brick in the direction of the continuous cavities depends essentially on the total cross-sectional area of the webs located between the cavities and is therefore proportional to the bulk density of the brick. On the other hand, the thermal insulation capacity between the end faces depends not only on the cross-sectional area of the webs, but also on the entire path length, which is decisive for the heat conduction along the webs. Given the given compressive strength and thus the given volume fraction of the entire cavity, it is therefore possible to achieve a particularly large path length and thus a correspondingly good thermal insulation by suitable shaping and arrangement of the cavities and the webs separating them.

Bricks in which the heat conduction along a zigzag path takes place due to a special shape and arrangement of vertically continuous cavities known, for example from DE-22 39 969-A, DE-25 32 030-A, DE-26 40 064-A, DE-27 14 840-A, DE-29 04 129 A, DE-911 539-C and CH-424 170-A. However, none of these previous publications describes a large-sized block with good thermal insulation properties.

In particular, DE-27 14 840-A describes a masonry brick which is penetrated in the vertical direction by cavities, each of which has in cross section the shape of two trapezoids that abut one another with their top sides. The cavities are arranged in such a way that trapezoids lie in rows, with the base sides of adjacent trapezoids lying next to one another in each row, separated by a web. Adjacent rows are offset by the height of the trapezoid. The bridges of this brick are very narrow, so that its compressive strength is so small that the use of this brick is out of the question for most masonry.

The object of the invention is therefore seen, starting from a prior art according to DE-27 14 840-A, to propose a brick of the type mentioned which, in addition to a high thermal insulation capacity, has a relatively high compressive strength and which is designed such that it can be adapted to various purposes by making slight modifications to its basic shape in terms of production, without impairing its compressive strength, its strength in general and its thermal insulation capacity.

According to the invention, this object is achieved by the features of the characterizing part of patent claim 1.

Advantageous developments of the brick according to the invention are defined by claims 2-5.

The use of masonry bricks according to claims 1 and 5 is proposed in claims 6 and 7, respectively.

The new masonry brick thus has webs which correspond in cross-section to the mean width of the cavities (ie the smallest width of the cavity), so that its compressive strength is considerable with good thermal insulation properties; As a result of the ratio between the webs and the cavities, which is at least approximately in the range of 1: 1, the masonry brick is characterized by slight Modifications to its basic shape, problem-free in terms of production, can be adapted to special needs, while its pressure resistance and thermal insulation ability are retained.

Such a modification consists, for example, in that one or more of the cavities which adjoin one of the abutting surfaces and whose cross section is therefore formed by only one trapezoid, with the exception of a vertical channel, are filled with brick material. Channels of this type are generally necessary for attaching fitting devices or guides during the construction of the masonry and / or for receiving lines. As such, the filling could be added later; but it is much easier to make them integral with the brick. The arrangement of the filling would result in an improvement in the thermal conductivity and thus a deterioration in the thermal insulation capacity without countermeasures; So that this disadvantage does not occur, a countermeasure is provided, in continuation of each row in which there is a channel, to provide a groove-like indentation which penetrates the wall brick vertically and protrudes inwards from the abutting surface and has approximately the width of the trapezoidal cover side. As a result, the existing material is reduced by a volume that almost corresponds to the additional volume provided by the filling, and despite the filling, a zigzag path for heat conduction is obtained. The manufacture of the channel or the filling and the indentation is only possible because the webs and the cavities of the brick have approximately the same dimensions in cross section, so that the filling does not cause abrupt differences in wall thickness, which have a very unfavorable effect in terms of production and strength.

When installing masonry from the masonry bricks according to the invention, it is advantageous if they have a preferably central mortar pocket which penetrates the masonry brick vertically on at least one of their abutting surfaces.

In general, the masonry to be erected from the masonry bricks is not smooth, but it is also necessary to be able to produce corner areas which jump in and out, stop points, falls and the like. For this purpose, a special development of the masonry brick according to the invention with flat predetermined breaking points is suitable, along which the masonry brick can be easily divided into a first partial brick in cuboid shape and into a second partial brick in L shape. The predetermined breaking points run along two vertical planes which are perpendicular to one another and extend from the vertical central axis of the brick to one of the end faces or one of the abutting surfaces. Of the The first partial brick contains one of the vertical edge areas of the original brick, while the second partial brick contains the remaining three edge areas of the original brick. It should be noted that the division of the brick into partial brick is only possible in a simple manner, for example by means of a hammer blow, because the wall thicknesses of the webs are not too small and essentially constant. A modification of the original masonry brick into a simple masonry brick is therefore only possible because, according to the invention, the wall thicknesses of the webs are approximately constant and are in the order of the widths of the cavities.

The predetermined breaking points are arranged in such a way that the first cuboid partial brick has a length and a width which are equal to half the length and half the width of the original brick.

The brick according to the invention is used to erect simple, smooth masonry.

The partial masonry bricks according to the invention are used, together with the masonry bricks according to the invention, for the production of more complicated masonry with corners, stop surfaces, lintels and heels.

Fig. 1

zwei Mauerziegel in einem Horizontalschnitt, je teilweise dargestellt, wobei aus der unteren Hälfte der Fig. 1 ein erster, einfacher Mauerziegel und aus der oberen Hälfte der Fig. 1 ein zweiter, Sollbruchstellen aufweisender Mauerziegel ersichtlich ist.

The invention is described in detail below using an example and with reference to the drawing. It shows

Fig. 1

two masonry bricks in a horizontal section, each partially shown, a first, simple masonry brick from the lower half of FIG. 1 and a second masonry brick having predetermined breaking points can be seen from the upper half of FIG. 1.

To make the description easier to understand, it should be noted that the base of the trapezoid is understood to mean the longer of its parallel sides, the top of the shorter side of its parallel sides and its height the distance of its parallel sides.

The brick shown in Fig. 1 is delimited by four vertical edge webs. It has two vertical end faces A, B, which are intended to form the inner and outer surfaces of a masonry, and two butt faces C, D, which are intended to form butt joints with neighboring other masonry bricks arranged at the same height in the masonry, and - running parallel to the plane of the drawing -, a horizontal floor surface and a horizontal top surface, to form mortar joints with bricks arranged underneath or on top of them. The brick has a number of prismatic cavities 1, 1A, 1C that penetrate it vertically. Each cavity 1 , but not the cavities 1A, 1C adjoining the end faces and abutting surfaces A - D , has an elongated cross section, which is composed of two trapezoids, the top sides of which coincide. The base sides of the trapezoids, which are oriented parallel to the cover sides, adjoin webs which separate the cavities 1 from one another. The cavities 1, 1A, 1C form rows which run parallel to the end faces A, B of the brick. Adjacent rows are offset from one another by the height of a trapezoid, ie by half the length of the cavities 1 .

As already mentioned, the cavities 1A adjoining the end faces A, B and the cavities 1C adjoining the abutment surfaces C, D are designed differently than the cavities 1 described so far. The cavities 1A are delimited in a straight line by edge webs forming the end faces A, B. Of the cavities 1C , every second one does not consist of two but only one trapezoid, the top side of which adjoins the edge webs forming the abutting surfaces C, D.

The wall thickness of the webs separating the cavities 1, 1A, 1B is equal to the average width of the prismatic cavities 1 and somewhat less than the wall thickness of the four edge webs.

Of the cavities 1C adjacent to the abutting surface D , the cross section of which consists of only one trapezoid, six cavities contain a filling of the same material as the brick, which was formed integrally with the brick, and which only leaves an approximately square channel 3 . In continuation of the rows with the channels 3 , the edge web forming the abutting surface D has groove-shaped indentations 6 which protrude into the masonry brick and penetrate it vertically.

Grooves 4 are provided on the end faces A, B and on part of the abutting surface C , which serve for better adhesion of the plaster to be applied later.

1 also shows two vertical planes E, F which are perpendicular to one another and along which center webs extend, the wall thicknesses of which approximately correspond to the wall thicknesses of the edge webs. Along the vertical planes E, F , which halve the end faces or the abutment surfaces B and C , in the central webs there are cylindrically shaped cavities 7 which penetrate the brick vertically and form predetermined breaking points, along which the brick can be separated into two partial brick . The first partial brick that is created during the separation contains a corner area of the original brick and has a cuboid shape; the second partial brick that is created contains three corner areas of the original brick, has an L-shape and is essentially three times the size of the first partial brick. The partial brick is suitable for the production of corners, stop surfaces and lintels.

In the edge web of the butting surface C there is also a mortar pocket 2 which is intended to be filled with mortar after the 'crunching' pushing of the brick.

A conventional masonry brick with the dimensions 25.4 x 38.8 x 24 (each in centimeters) and with a cavity arrangement according to FIG. 1 , which was fired to produce fine pores from a clay mixture with the addition of wood flour, has a mass of 19.464 Kilogram. The otherwise determined density of the porous clay shard is 1.578 kilograms per cubic decimeter. The proportion of voids is calculated to be 47.97% of the total volume. The compressive strength of the brick between the floor and top surface in the vertical direction was determined to be 20 Newtons per square millimeter. The measurement of the thermal insulation resulted in a K value of 0.43 watts per square meter and K for the masonry brick alone; for masonry with 2.5 centimeters of exterior plaster and 1.5 centimeters of interior plaster, the K value was 0.397. These values compare advantageously with corresponding values for the compressive strength of 20 Newtons per square millimeter and a K-value of 0.7 for a conventional module block of corresponding dimensions with the same void fraction but with conventional perforation.

Claims (10)

1. A building block in ashlar form made of fired clay,
      having two mutually opposite, vertical end faces (A,B) which are intended to form the external faces of a wall, two mutually opposite vertical abutting faces (C,D) which are intended for the production of butt joints with adjacent building blocks, and having two mutually opposite horizontal faces which form the bottom face and the top face and which are intended for the formation of coursing joints,
   wherein
      a multiplicity of continuous, prismatic cavities (1, 1A, 1C) which are separated by webs passes vertically through the building block, each of which cavities (1) which is not adjacent to an end face (A,B) or abutting face (C,D) has the shape of two trapeziums which are contiguous at their top sides, and which cavities (1) are arranged with adjacent bottom sides of their trapeziums, which are separated by webs, in rows parallel to the end faces,
   and wherein
      adjacent rows are each mutually offset by the height of the trapeziums, whilst the cavities (1A) adjacent to the end faces (A,B) are delimited linearly on their sides facing the end faces (A,B), and each second one of the cavities (1C) adjacent to the abutting faces (C,D) has a cross-section corresponding to only one trapezium,
   characterised in that

   - the cavities in the cross-section which is revealed on the bottom and top faces appear in the form of oblong slits with a width which decreases by half from both ends to the middle,

   - that the webs (1, 1A, 1C) separating the cavities have a substantially constant wall thickness corresponding to the smallest width of the cavity (1), so that the total volume of the cavities (1, 1A, 1C) amounts to 40 - 50 % of the volume of the building block, and

   - that secondly the building block is provided with pre-formed, scheduled breaking points (7) in two planes (E,F) which intersect on the vertical centre line of the block and which are perpendicular to an end and side face, respectively, bisecting the latter, the effect of which scheduled breaking points is that a quarter of the block can be separated along these two vertical planes by a hammer blow, whereby two separately usable portions of unequal size are formed.
2. A building block according to claim 1, characterised in that some of the cavities (1C), the top sides of the trapeziums of which are adjacent to one of the abutting faces (D), contain a filling of fired clay except for a channel (3) which is approximately square.
3. A building block according to claim 2, characterised in that, in continuation of each row which contains a channel (3), groove-like indentations (6), which start from the abutting face (D), which pass vertically through the building block, and the width of which corresponds to the top side of the trapeziums, project into the filling.
4. A building block according to any one of claims 1 to 3, characterised in that a central mortar pocket (2) which passes vertically through the building block is provided on at least one of the abutting faces (C).
5. A building block according to any one of claims 1 to 4, characterised in that the building block can be split along vertical planes (E,F) into a first partial building block in ashlar form which contains the said edge region, and into a second partial building block in the shape of an L which contains the remaining edge regions.
6. A building block according to any one of claims 1 to 5, characterised in that the webs are thickened along the external faces (A,B,C,D) and along the separating planes (E, F).
7. A building block according to any one of claims 1 to 6, characterised in that grooves (4) are provided on the end faces (A,B) and on part of the abutting face (C).
8. A building block according to any one of claims 1 to 7, characterised in that it is fired from a clay mixture with the addition of wood flour for the production of fine pores.
9. The use of the building block according to any one of claims I to 8 for the construction of single-layer, heat insulating brickwork.
10. The use of the building block according to any one of claims 1 to 8 for the construction of corner and end regions of single-layer, heat insulating brickwork.

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