EP1558822A1

EP1558822A1 - A building element arrangement

Info

Publication number: EP1558822A1
Application number: EP03757085A
Authority: EP
Inventors: Unto Ensio Keskinen
Original assignee: U-H Rakennus Oy
Current assignee: U-H Rakennus Oy
Priority date: 2002-06-10
Filing date: 2003-06-10
Publication date: 2005-08-03
Also published as: WO2003104577A1; FI20021110A0; FI20021110A; AU2003232274A1

Abstract

The present invention relates to a building element (1) made of masonry blocks (2), to which element means (7) for hoisting said element are associated. Said means include bars (6) which extend vertically through said masonry blocks and which are arranged in respective channels (5) arranged in superimposed masonry blocks, so that each bar (6) by means of a grouting compound is attached to each superimposed masonry block (2, 2a). The present invention also relates to a method for the production of a prefabricated building element (1) by means of bricklaying.

Description

A BUILDING ELEMENT ARRANGEMENT

The present invention relates to a wall-like prefabricated building element made of masonry blocks and a hardening binding material compound arranged between said blocks, where means for hoisting said element are associated thereto. The present invention further relates to a method for the production of a prefabricated building element manufactured by laying separate masonry blocks such as blocks of lightweight aggregate concrete .

The building industry knows many kinds of prefabricated building elements by means of which a part of the tasks related to building can be transferred from the building site to be carried out under factory-like conditions. Typically, such prefabricated building elements include different kinds of wall, pillar and floor entities which constitute the body of a building.

The handling, transportation and installation of such prefabricated building elements require that one or preferably several secure and easily used attachment points are arranged at the elements, by means of which attachment points the element can be connected to a hook or the like at a hoisting device .

Until now most prefabricated building elements constitute wall entities cast of concrete, but beside these nowadays also prefabricated building elements made of masonry* blocks such as bricks, blocks of lightweight aggregate concrete and such materials have been introduced, so that the advantages of on-site laid structures and, on the other hand, prefabricated element structures can be combined.

However, a problem related to such structures has until now been the fact that the arrangement of sufficiently reliable attachment points in a masonry structure has been difficult. Further, an element formed of separate masonry blocks will to its structure, as such, be weaker than, e.g., a concrete element, and thus special care must be observed at the handling of such an element . Especially a block of lightweight aggregate concrete is traditionally considered to be a masonry block which easily breaks, and thus also the handling of a prefabricated building element constituted of such blocks has been considered as somewhat difficult.

For said reasons, i.a., Finnish patent application No FI-20010301 by the same applicant discloses a structure wherein brackets which serve hoisting and other handling are supported by a solid-structure supporting beam which extends under the element. In some cases, however, such a beam is disadvantageous, and for this reason a primary object of the present invention is to disclose such a supporting structure where there is no necessary need for a continuous supporting beam under a prefabricated building element .

The present invention is based on the realization that, regardless of the fact that the total weight of a prefabricated building element may be very considerable, a sufficient requirement for hoisting an element is that for each respective layer of masonry blocks the weight of the layer can be distributed on that part of hoisting means which extends at that layer. Surprisingly, it has been found that this knowledge can be adapted also for lightweight aggregate concrete blocks and the like masonry blocks which earlier have been considered to be weak, as such. Thus, the problem discussed above can be solved in the manner disclosed in the appended claims. In this way, a prefabricated building element according to the present invention is characterized in that the means for hoisting the building element includes one or several elongated structural pieces, each of which extending essentially through the element in the vertical direction and which is arranged, respectively, in a channel which is constituted by cavities arranged in superimposed masonry blocks, so that said structural piece is attached at the respective cavity, by means of a grouting compound, to each superimposed masonry block.

Correspondingly, the method according to the present invention is characterized in that vertical cavities, suitably holes, are arranged in at least in some of the vertically superimposed masonry blocks of the prefabricated building element, which cavities pass through all the masonry blocks at the respective location and into which respective cavities a vertical structural piece is arranged to connect the superimposed masonry blocks. Said structural piece is fixed, by means of a hardening material compound, to each masonry block and thus the uppermost portion of a structural piece attached to each of said masonry blocks can be utilized for hoisting the building element and for installing it at the final installation site.

The invention will now be described in more detail by means of example and referring to some preferred embodiments and to the appended drawing, wherein

Figure 1 in a perspective view discloses a prefabricated building element in accordance with the present invention, in which element double blocks are used as said masonry blocks, said blocks including, as such, an insulating layer arranged between opposite hard walls,

Figure 2 in section discloses the lowermost layers of masonry in a wall structure as disclosed in Figure 1, and

Figure 3 in a side view discloses a larger wall entity where several prefabricated building elements in accordance with the present invention are arranged side-by-side. According to Figure 1 a prefabricated building element 1 is constituted of several superimposed masonry blocks 2 such as blocks of lightweight aggregate concrete blocks, gas concrete blocks, bricks or the like elements which as such are known to be used in masonry. Said blocks are separate, as such, and they are arranged in a side-by-side position and interconnected, in a manner known per se, by means of mortar or the like hardening material compound 4. The wall structure disclosed in the Figure is a double structure wherein an insulation layer 3 is arranged between the block portions 2 ' , 2" which constitute the wall surfaces. Favorably, such a wall structure is laid of, e.g., such lightweight aggregate concrete blocks which already as such include two hard portions based on lightweight aggregate concrete and an insulation 3 arranged therebetween in connection with the manufacture, but a similar structure can also be achieved on the actual place where the actual building element 1 is manufactured by arranging a layer of insulation 3 between two block wall structures which are separately laid. In this connection there is reason to observe that the inventive arrangement of course also can be utilized for the fabrication of such elements which have a simpler structure as well, such as, e.g., walls having only one solid masonry block in the transversal direction.

According to the present invention at least one channel 5 constituted of mutually centered cavities 5 ' arranged in superimposed blocks 2, 2a extends vertically through the prefabricated building element 1. In this channel an elongated mainly rod-like structural piece 6 is arranged, such as a ribbed bar, a threaded bar or some other piece having a corresponding tensile strength. Said rod-like structural piece 6 extends vertically essentially through the whole building element 1, and the structural piece is attached, by means of, e.g., grouting compound 20 or the like binding material compound which is introduced into the channel 5, to each such superimposed block 2, 2a through which the channel 5 and, correspondingly, the rod- like structural piece 6 extend. Thus the structural piece 6 will be attached to each of the blocks, i.e. it will pick up the load at all block layers. In this manner the load constituted by the building element's 1 own weight is uniformly distributed along the whole vertical extent of the structural piece 6, so that there actually will not necessarily be any need for any such binding, lock or other prior art means acting especially at the lowermost part of the building element 1.

Thus, it has surprisingly been found that in this manner a structural piece 6 which is connected to each of the block layers, such as a ribbed bar or the like, by itself can take a considerably high load, and it has equally surprisingly been found that this applies also for such masonry blocks 2, 2a like lightweight aggregate concrete or gas concrete blocks for which the structural breaking strength often has been considered even considerably inferior to the strength of, e.g., baked bricks. In practice it has turned out that the ribbed bar 6 cannot be detached from the wall structure constituted of a prefabricated building element 1 in any other way than by breaking the individual blocks 2 of the wall structure, and in the same way it has been found that, e.g., an element laid of lightweight agglomerate concrete blocks also withstands, as an entity, even a high tractive force directed to such a structural piece 6 even in a case where no special anchoring of said structural piece in the lowermost layer of masonry blocks has been provided. It has further been found that this also applies in cases where the masonry block itself comprises, e.g., an insulation material layer 3 arranged between two side portions 2', 2" made of a mineral material. Thus, a prefabricated building element arranged in accordance with the present invention can be hoisted, also as such, by means of said structural piece 6, provided that care is taken so that the dimensioning of said structural piece 6 as such is adapted in accordance with the weight of the building element 1. With respect to handling as well as to loading it is appropriate that each wall type building element 1 comprises several hoisting points and thus in the case according to Figure 1 an arrangement is disclosed, where the number of hoisting lugs 7, 7a, 7b constituted by structural pieces 6 attached in accordance with the present invention is three .

Figure 1 discloses, in an exemplifying manner, different hoisting lug solutions, although only one type of lug structure normally is used for the individual element . A hoisting lug 7 as disclosed in Figure 1 is constituted so that two parallel structural pieces 6, 6', which suitably consist of one ribbed steel bar bent essentially into the shape of a U, are attached to channels 5 which have been arranged in adjacent wall portions 2', 2". A similar structure, at which an intermediate plate 8 has been arranged to prevent any possible breakage of the uppermost block layer, is indicated by means of reference 7a. Reference 7b discloses a structure wherein the hoisting lug comprises a separate piece 9 made of, e.g., angle iron, which is attached to the preferably threaded upper portion of the structural pieces 6 by means of, e.g., nuts 10. Also in this embodiment the upper portion can be an extension of a ribbed bar or the like, or, more favorably, a threaded bar which is juxtaposed with the ribbed bar in the same channel 5 a suffiently long way in view of securing load carrying properties by means of, e.g., a grouting mortar 20.

In Figure 2 (from which Figure, for clarity reasons, the mortar layers 4 between the blocks as well as the grouting mortar fillings 20 in the channels 5 have been omitted) a structure as disclosed in Figure 1 has been shown in section and in a larger scale. Here the lowermost block 2b is favorably made as a beam block so that within the block having a generally U-shaped cross section, an insulation 3' has been arranged and further a beam 11 has been cast of, e.g., concrete, said beam suitably having a separate reinforcement 16 and favorably extending along the length of the lower edge of the whole prefabricated building element 1. Beside the fact that this beam 11 stiffens and supports the lower part of the element said beam 11 at the same time constitutes an element which interconnects the interlacing ends 13 of structural pieces 6, 6' which have been bent in, through an opening 12 separately opened from a cavity 5" and transversely in relation to the main plane of the building element, into the block, which arrangement renders the structure especially strong.

As disclosed in Figure 2 it is appropriate, in a double wall structure comprising an insulation 3 , that the walls on both sides of the insulation 3 are interconnected, in a manner known per se, by means of stirrup reinforcings 14 which extend transversely in relation to the wall surface. Correspondingly, it is usually appropriate in order to guarantee the strength of the prefabricated building element that longitudinal reinforcement steel bars 15 are arranged in the mortar joints between the separate brick layers, in which case the building element 1 due to the reinforcements 6 and 15 which, in practice, extend crosswise will be so strong that further reinforcement like the beam structures used until now in connection with masonry wall elements will not be needed at all. Practical experiments have shown that a prefabricated building element 1 made in this manner and having hoisting lugs 7, 7a, 7b attached thereto in accordance with the present invention withstands all such loads, including a dropping of the element, which the manufacturing material of the masonry blocks used for the element will withstand as such.

A such, said cavities 5' made in the masonry blocks 2, 2a, 2b, 2' and 2" for the through channel 5 can be made, e.g., by drilling into the masonry blocks, or they can be made already during the manufacture of the masonry blocks . According to one embodiment of the present invention said cavities 5 ' are made to have a slightly ragged surface in which case the attachment of the structural pieces 6 therein is especially effective. According to another embodiment of the invention said cavities 5 ' are slightly conical so that the diameter of their upper end is narrower than the lower end, in which case a disengagement of the structural piece 6 is especially effectively prevented. Generally it has been found, however, that already a ribbed steel bar 6 attached to a smooth surface channel 5 by means of grouting mortar 20 or the like hardening material compound is sufficiently well anchored in a block wall and that such a wall as such well withstands the strains occurring during manufacture, transportation and installation.

Favorably, the elements according to the present invention are manufactured so that their height correspond to the height of the floor height of the final building. However, in the lateral direction the demands set by the practical handling may set practical restrictions to the length of the elements . Thus, Figure 3 discloses how, e.g., a coherent wall structure can be achieved by means of subsequent elements 1', 1 and 1". The mutual attachment of subsequent elements can easily be effected by means of a structure according to a further development of the present invention. Therein structural pieces 17, favorably ribbed steel bars, are arranged in at least some of the horizontal seams 4 ' which extend between the masonry blocks 2, 2a, which seams are filled with mortar or some other hardening binding material compound, said structural pieces 17 extending out beyond the edge of the edge of the prefabricated building element 1 and suitably so that the structural pieces 17 are bent essentially into the direction of the edge. When such building elements 1, 1', 1" in connection with the installation are arranged in a subsequent manner, zones between the element^'s 1, 1' and, respectively, 1, 1" will be formed. Said zones include dovel bars 17 and in these zones a wall portion which binds together subsequent elements can be made, e.g., on site by means of mortar pouring 18 using, e.g., a mould.

Figure 3 further discloses that a hoisting beam 19 extending essentially over the length of the prefabricated building element 1 is favorably used for hoisting the element, which hoisting beam is attached to several hoisting lugs 17 for the hoisting and other handling. Figure 3 further discloses a hoisting fitting which is developed especially for one integral block wall, where the hoisting lug 7c is arranged so that said structural piece 6 is bent above the building element 1 back into the vertical channel 5 made in the building element and so deep that the necessary strength required for the managing of the hoisting force is achieved, by means of a grouting or the like hardening filling material compound 20 arranged in said channel 5, in the binding to a portion of a structural piece 6" which extends to the bottom of the building element 1. Figure 3 further discloses that in some cases the constancy of the elongated structural piece 6 further can be safeguarded so that the lower end 2-1. of the structural piece 6 is bent into a horizontal position also in such wall structures where there is no insulation between two opposite walls .

Above some favorable embodiments of the present invention have been disclosed in an exemplifying manner, but for the professional it is clear that the present invention can be adapted also in many other ways within the scope of the appended claims .

Claims

1. A wall-like prefabricated building element (1, 1', 1") made of separate masonry blocks (2, 2a, 2b) as well as of a hardening binding material compound (4) arranged between said blocks (2, 2a, 2b), and means (7, 7a, 7b, 7c) for hoisting said element being associated thereto, c h a r a c t e r i z e d in that said means for hoisting said element include one or several elongated structural pieces (6, 6', 6") which extend vertically essentially through said element (1, 1', 1"), which pieces are arranged in respective channels (5) constituted by cavities (5') which are arranged in respective superimposed masonry blocks (2, 2a), so that said structural piece(s) (6, 6', 6") by means of a grouting compound (20) will be attached to each superimposed masonry block (2, 2a) at the respective cavity (5) .

2. An element as defined in claim 1, c h a r a c t e r i z e d in that said elongated structural piece (6, 6') is constituted by a ribbed bar or the like rod-like piece (6") which favorably extends in the vertical direction essentially through the whole of the building element (1, 1', 1") .

3. An element as defined in claim 1 or 2 , c h a r a c t e r i z e d in that said structural piece (6, 6', 6") is bent, at the lower edge of a lowermost masonry block (2b) of the building element (1, 1', 1"), in a transversal direction (13, 21) , suitably so that the ends (13) of two parallel structural pieces (6, 6'), which ends are bent towards each other, will be at least partially overlapping at the lower ^' portion of the lowermost masonry block (2b) and favorably so that a hardening binding compound is arranged around said overlapping ends (13) of said structural pieces (6, 6') favorably so that said binding compound at the same time constitutes a beam (11) which extends in the longitudinal direction through said building element (1, 1', 1").

4. An element as defined in any one of claims 1 to 3 , c h a r a c t e r i z e d in that said masonry blocks (2, 2a, 2b) are blocks made of lightweight aggregate concrete or gas concrete, favorably double blocks comprising a central insulation layer (3), between which blocks (2, 2a, 2b) there are appropriate horizontal and vertical layers of mortar (4, 4 ' ) , favorably so that horizontal and/or transversal reinforcing elements (14, 15) such as favorably ribbed and/or hooked steel rods are associated with at least some of said horizontal layers (4, 4') of mortar.

5. An element as defined in claim 4, c h a r a c t e r i z e d in that the lowermost row (2b) of blocks in a double-block element (1, 1', 1") comprising a central insulation (3) comprises beam blocks having a U-shaped transversal section and including an essentially unbroken lower portion, in which case said structural pieces (6, 6', 6") are taken down to said unbroken lower portion of the block and bent inwards above said lower portion into a trough constituted by said beam block, in which trough said bent end(s) (13) is (are) fixed by means of a hardening compound (11) .

6. An element as defined in any one of claims 1 to 5, c h a r a c t e r i z e d in that said channel (5) arranged for said structural piece (6, 6', 6") comprises subsequently arranged vertical cavity channels (5') which favorably have an at least to some extent rough surface, which cavity channels are arranged in each masonry block (2, 2a, 2b) or in a portion (2', 2") thereof in connection with the manufacture of said masonry block (2, 2a, 2b) or separately made therein by means of, e.g., drilling.

7. An element as defined in any one of claims 1 to 6 , c h a - r a c t e r i z e d in that a hoisting lug (7, 7a, 7b, 7c) is arranged at the upper end of said structural pieces (6, 6', 6") either so that a rod-like structural piece (6, 6',. 6") is bent above the actual building element (1, 1', 1") and back into the vertical channel (5) which has been arranged in the building element (1, 1', 1") or so that a threading or the like locking or tightening means is arranged at the upper portion of said structural piece (6, 6', 6") or at a separate piece associated thereto, by means of which means a separate hoisting lug element (9) is attached to said structural piece (6, 6', 6") in a manner which takes a tensional load.

8. An element as defined in any one of claims 1 to 7, c h a - r a c t e r i z e d in that structural pieces (15) , favorably ribbed bars, are arranged in the vertical seams (4') between at least some of the masonry blocks (2, 2a, 2b) or portions

(2', 2") of such blocks and suitably so that said structural pieces extend also outside of the edge of said prefabricated building element, wherein such portions (17) of said structural pieces which extend beyond the surface of said edge suitably are bent into a direction which is essentially parallel to said edge, so that adjacent building elements (1, 1', 1") can be mutually attached especially at their edges by means of said portions (17) in connection with a mortar pouring (18) or the like.

9. A method for the production of a prefabricated building element (1, I¹, 1") by laying separate masonry blocks (2, 2a, 2b) such as blocks of lightweight aggregate concrete, c h a - r a c t e r i z e d in that such vertical subsequent cavities

(5'), favorably holes, which extend through all superimposed masonry pieces (2, 2a, 2b) are arranged at at least some locations at said building element (1, 1', 1"), and that a vertical rod-like structural piece (6, 6', 6") is arranged in channels (5) which are constituted by said cavities (5'), which structural piece (6, 6', G") interconnects said superimposed masonry blocks (2, 2a), and fixing said structural piece by means of a hardening compound (20) to each masonry block (2, 2a, 2b), whereby the uppermost portion of the structural piece (6, 6', 6") which piece thus has been fixed to each of said masonry blocks (2, 2a, 2b) can be utilized for hoisting the prefabricated building element and for positioning it at a final installation site.

10. A method as defined in claim 9, c h a r a c t e r i z e d in that a lowermost portion (13, 21) of said rod-like structural piece (6, 6', 6") is bent to extend in a transverse direction in a trough (12) which has been separately arranged in the lowermost masonry block (2b) .