EP1354102A1

EP1354102A1 - A method of assembling wall or floor elements

Info

Publication number: EP1354102A1
Application number: EP02715383A
Authority: EP
Inventors: Henning Larsen
Original assignee: Danmarks Tekniskie Universitet
Current assignee: Danmarks Tekniskie Universitet
Priority date: 2001-01-22
Filing date: 2002-01-22
Publication date: 2003-10-22
Also published as: WO2002057556A1

Abstract

The invention relates to a method of constructing, at the site of use, a building wall (1) or a building floor (1) using a plurality of prefabricated concrete or lightweight concrete plate-shaped wall of floor elements (10), in particular cast elements, which have a front side and a rear side as well as longitudinal side edges faces (12), wherein the elements (10), in a first step, are arranged at the site of use in mutual extension and then, in a second step, are connected with each other by means of at least one force-transferring device to form a tight connection. The invention is characterized in that a circular ring-shaped depression (20) is provided on the front side and/or the rear side of two adjoining elements (10) after the first step, said circular ring-shaped depression extending in the one as well as the other element (10), that the force-transferring device is a pipe (25), and in that the pipe (25) is inserted into said circular ring-shaped depression (20) in the second step.

Description

A method of assembling wall or floor elements

The present invention relates to a method of constructing, at the site of use, a building wall or a building floor using a plurality of prefabricated concrete or lightweight concrete plate-shaped wall or floor elements having a front side and a rear side as well as longitudinal side edge faces, wherein the elements, in a first step, are arranged at the site of use side by side in mutual extension and then, in a second step, are connected with each other by means of at least one force-transferring device to form a force-transferring connection between the elements.

It is known to assemble prefabricated concrete elements and certain types of lightweight concrete elements by means of reinforcing bars, which are embedded in various ways in the joints between the elements when these have been erected at the site of use. The joint is then concreted. This is a relatively cumbersome working process, which is time-consuming, and which moreover requires a special configuration of the side edge faces of the elements.

It is also known to assemble certain types of lightweight concrete elements by gluing, which requires great carefulness.

The object of the present invention is to provide an improved method of assembling prefabricated concrete elements, making it possible inter alia to establish a force-transferring connection between the elements in a shorter time and with great certainty of the carrying capacity of the connection.

This is achieved in that a circular ring-shaped depression is provided on the front side and/or the rear side of two adjoining elements after said first step, said circular ring-shaped depression extending in the one as well as the other element, that the force-transferring device is a pipe, and in that the pipe is inserted into or is formed in said circular ring-shaped depression in the second step. By forming the depression after the elements are arranged in their final position, corresponding to their location in the final building, the depression will present a well-defined circular shape which makes it possible to insert a preformed pipe, which transfers the forces applied.

The precise number of depressions with associated pipes will depend on the forces applied, but it is preferred that at least two circular depressions are formed along adjoining side edge faces into which depression a respective force-transferring device of the said type is inserted or formed. In particular, two elements may be connected along the adjoining side edge faces by means of four to eight pipes arranged at a mutual distance of between 10% and 25% of the height of the building wall, either on the same side or on both sides of the wall.

The at least one ring-shaped depression may be provided in a particularly simple manner by means of a rotating cutting tool which is coupled to an or- dinary drilling machine. It is contemplated that the cutting tool may optionally be shaped as an integral part of the pipe.

Owing to the forces applied it is preferred that the depth l_ι of the ring-shaped depression is between about 20% and about 70% of the thickness L₂ of the concrete elements, preferably between about 30% and about 50% of L₂, and that the ring-shaped depression extends symmetrically in adjoining elements.

It is preferred that the pipe is fixed in the ring-shaped depression immediately after its insertion, e.g. using a filling and adhesive material which is pressed into the ring-shaped depression before or after the insertion of the pipe, and which is subsequently caused to harden. After or prior to this, a sealing material is inserted between the longitudinal side edge faces.

If the invention is used for making a building floor, the ring-shaped depres- sion may be formed in the upwardly directed surface of the floor. If, alternatively, the invention is used for making an external building wall, the ring- shaped depression may advantageously be formed in the wall surface directed toward the interior of the building. A preferred embodiment of the invention will be described more fully below with reference to the drawing. In the drawing:

Fig. 1 shows the front side of a building wall consisting of four wall elements lifted in place by the use of a crane,

Figs. 2a and 2b show an enlarged section of fig. 1 , seen from the front and in cross-section, respectively,

Figs. 3a and 3b show an enlarged section of fig. 1 , seen from the front and in cross-section, respectively, after the insertion of a connecting device, and

Fig. 4 shows an example of a connecting device.

In fig. 1 , reference numeral 1 generally designates an essentially plane building wall which consists of four prefabricated plate-shaped wall elements 10 formed from conventional concrete, lightweight aggregate concrete or lightweight concrete. The wall elements 10, whose front side is visible in fig. 1 , preferably have a height which corresponds to a storey in the building con- cerned, and the elements 10 have longitudinal parallel side edge faces 12 and transverse parallel side edge faces 14. The elements 10 are arranged with the longitudinal side edge faces 12 adjoining each other and are interconnected at the joint 8 via force-transferring devices, there being arranged a suitable sealing material in the joint 8 itself. An element 10 formed from 2,300 kg/m³ concrete and having a thickness x width x height of 0,12m x 4,0m x

3,0m will have a weight of about 3,300 kg while an element 10 formed from aerated concrete with a density of 600 kg/m³ and a thickness x width x height of 0,12m x 0,6m x 3,0m will have a weight of about 130 kg.

In fig. 1 , the arrows indicate some of the forces normally occurring in such a building wall, in the plane of the wall, and the force-transferring devices must be dimensioned to transfer a significant part or all of these forces.

In conventional building constructions with prefabricated wall elements, the side edge faces comprise recesses into which force-transferring devices in the form of reinforcing bars are inserted after the elements have been arranged at the site of use. The joint between the elements is then concreted, thereby establishing a force-transferring connection.

In contrast to conventional building constructions, the elements 10 used in the invention may have plane side edge faces. This enables simplified manufacture of the elements 10.

Fig. 1 shows a point of time after a first step of the establishment of the build- ing wall, where adjoining elements have been arranged in the correct mutual position, i.e. in a position corresponding to the desired final position in the building of the elements. At this time, the elements 10 have just been prepared for being assembled with a plurality of specially configured force- transferring devices. As will be seen, four mounting locations 20 have thus just been formed for the force-transferring devices along each joint 8.

Figs. 2a and 2b show the configuration of the mounting locations in greater detail, and it will appear that a plurality of outwardly open circular grooves 20 are involved, shaped as depressions in the surface of the front side of the building wall 1. Each circular groove consists of two essentially semi-circular segments, with two associated semi-circular segments extending exactly opposite each other at the side edge face 12 of each element 10. This is a consequence of the groove 20 being formed in one operation after the elements 10 have been arranged in the final position.

It appears from fig. 2b that the groove 20 may have a depth l_ι which may correspond to about 40% of the thickness L₂ of the elements 10. The actual selection of this depth l_ι depends on the forces applied and the strength properties of the elements 10. It will moreover be seen in fig. 2b that the groove 20 is defined by an external circular face 22 and by an internal circular face 24. The internal circular face surrounds a two-part concrete core 21 which, as will appear, serves to transfer forces from one element 10 to the adjoining element 10 via a force-transferring device. Figs. 3a, 3b and 4 show an example of a force-transferring device 25 which is inserted into the groove 20 according to the invention. More particularly, the force-transferring device 25 is shaped as a pipe, i.e. it has a tubular shape, having external and internal dimensions, which are adapted to the di- ameter of the external circular face 22 and the internal circular face 24, respectively. The dimensions of the pipe 25 may thus optionally be selected so that the surface 25 of the pipe closely engages one of the circular faces 22,

24 and exerts a certain clamping force.

The extent of the pipe 25 into the plane of the paper in fig. 3a preferably corresponds approximately to the depth l_ι of the groove 20, as shown in fig. 3b, and it will be appreciated that, in certain cases, the force-transferring device

25 will appear as a ring rather than as a pipe. In general, the dimensions of the pipe 25 will have to be determined on the basis of the constituent mate- rials as well as the forces on the elements that give rise to tensions in the pipe 25. It is conceivable that the pipe 25 may be made of e.g. plastics or metal. It is also conceivable that the pipe 25 may be formed on location directly in the circular groove 20, e.g. by casting, using a cement-based material.

As shown, pipes 25 having the shape of a cylinder of revolution are preferred, but prismatic pipes, including straight hexagonal, heptagonal or octagonal pipes may also be contemplated for use. The pipe 25 shown in fig. 3b is shown schematically in fig. 4, from which it will appear that the pipe 25 may optionally also be provided with cutting edges or teeth 25', whose purpose will be explained more fully.

The shown circular groove 20 is preferably formed by means of a rotating cutting tool which has cutting teeth positioned along a circle with a diameter corresponding to the desired diameter of the groove 20. The cutting tool may preferably be adapted to be coupled to an ordinary drilling machine. If it is decided to shape the pipe 25 with the mentioned cutting edges or teeth 25', which may particularly be of interest in elements of lightweight concrete, the pipe 25 may conceivably be connected directly with the drilling machine and be configured such that it may be disconnected from it when the pipe has cut into the two adjoining elements 10.

To fix the pipe 25 in the groove 20 and thereby prevent unintentional with- drawal of the pipe, as well as to ensure an optimum transfer of forces, the groove 20 may be filled with a suitable adhesive material, such as cement mortar or glue, before or after the insertion of the pipe 25. The outwardly directed end face of the pipe 25 may be covered by this process so that the pipe 25 is no longer visible on the surface of the building wall 1. Since the adhesive material is to transfer forces between the pipe 25 and the adjoining circular faces 22, 24, the strength properties of the material, after hardening, must be selected in accordance with the forces applied.

It will be appreciated that the joint 8 between two adjoining elements may be provided with a suitable sealing material either before or after the interconnection of the elements 10 by means of the pipes 25.

The above description is particularly directed to a building wall, but it will be clear to the skilled person that the principles may also be applied in the con- struction of building floors consisting of several floor elements. The invention is moreover particularly directed to lightweight concrete elements for low buildings. Thus, particularly elements for forming internal building walls may be involved.

It is noted that, in certain cases, the invention may also be used for the connection of plate-shaped elements for use in the road construction industry.

Claims

Patent Claims:

1. A method of constructing, at the site of use, a building wall (1) or a build- 5 ing floor (1 ) using a plurality of prefabricated concrete or lightweight concrete plate-shaped wall or floor elements (10) having a front side and a rear side as well as longitudinal side edge faces (12), wherein the elements (10), in a first step, are arranged at the site of use side by side in mutual extension and then, in a second step, are connected with each other by means of at least l o one force-transferring device to form a force-transferring connection between the elements, characterized in

that a circular ring-shaped depression (20) is provided on the front side and/or the rear side of two adjoining elements (10) after the first 15 step, said circular ring-shaped depression extending in the one as well as the other element (10), that the force-transferring device is a pipe (25), and that the pipe (25) is inserted into or formed in said circular ring- shaped depression (20) in the second step.

20

2. A method according to the preceding claim, characterized in that the ring-shaped depression (20) is provided by means of a rotating cutting tool.

25 3. A method according to the preceding claim, wherein the elements (10) have a thickness L₂, characterized in that the depth l_ι of the ring- shaped depression (20) is between about 20% and about 70% of L₂, preferably between about 30% and about 50% of L₂.

30 4. A method according to one of the preceding claims, characterized in that the ring-shaped depression (20) extends symmetrically in said two adjoining elements (10).

5. A method according to one of the preceding claims, characterized in that the pipe (25) is fixed in the ring-shaped depression (20) immediately after its insertion.

6. A method according to one of the preceding claims, characterized in that an adhesive material is inserted into the ring-shaped depression (20) prior to the insertion of the pipe (25).

7. A method according to one of the preceding claims, characterized in that a sealing material is introduced between each of the adjoining elements (10).

8. A method according to one of the preceding claims, characterized in that the pipe (25) has the shape of a cylinder of revolution.

9. A method according to one of claims 1-7, characterized in that the pipe (25) is prismatic.

10. A method according to one of the preceding claims, wherein floor ele- ments (10) are assembled to form a building floor, characterized in that the ring-shaped depression (20) is formed in the upwardly directed surface of the floor.

11. A method according to one of the preceding claims 1-9, wherein wall elements (10) are assembled to form a building wall, characterized in that the ring-shaped depression (20) is formed in the surface of the wall (1) directed toward the interior of the building.

12. A method according to one of the preceding claims, characterized in that the pipe (25) comprises cutting teeth (25').