DEVICE FOR FIXING A STRUCTURAL ELEMENT TO THE END OF AN UPRIGHT TUBULAR STEEL COLUMN AND A METHOD FOR PRODUCING THE DEVICE

Abstract: Device, and a method for producing the device, for fixing a structural element (2) to the upper end of an upright, tubular steel column (1). The device comprises an elongated member (3) with a first part of the length of the member outside the column and a second part inside the latter. In the second part there are means (3b) designed, together with the walls of the column (1), to define a space for a setting casting compound (4), which is intended to fix the member (3) in the column (1). At least the first part of the elongated member (3) is designed to achieve fixing of the structural element (2).

Description: Device for fixing a structural element to the end of an upright tubular steel column and a method for producing the device The present invention relates to a device for fixing a structural element to the end of an upright tubular steel column and a method for producing the device according to the pre-characterising parts of the independent claims 1 and 5. Such devices and methods of fixing are already known, fixing elements being used in the form, for example, of plates and/or reinforcing rods welded to the end of the column. Welding means that rust protection and any other surface coatings on the column may be damaged, which means a risk of future corrosion damage and of stresses building up in the column. Furthermore, welding is an operation that calls for special expertise and one in which quality assurance is difficult. It also carries a potential fire hazard. There are not normally any welders present on a building site, for example, so that welding will mean that a further trade category has to be called in for this particular work. An object of the present invention is to produce a device and a method by means of which the above-mentioned disadvantages can be eliminated or at least reduced. According to the present invention a device for fixing a structural element to the end of an upright tubular steel column is produced according to the characterising part of claim 1 , whilst again according to the present invention a method of fixing a structural element to an end is created according to the characterising part of claim 5. Preferred embodiments also have any or some of the characteristics specified in the subordinate claims. The invention will be explained in more detail below with the aid of the drawing attached, the figures of which illustrate examples of embodiments of the device according to the present invention. Figure 1 shows a column with a projecting, elongated member for fixing to a structural element in the form of a beam on which a joist element rests. Figure 2 similarly to figure 1 shows the invention adapted to fixing a concrete slab to the column end and a column standing on the concrete slab. Figure 3 shows a diagram in perspective view of one embodiment of an elongated member with centring wires and a plate in order to define a space in a tubular steel column. Figure 4 shows a detailed perspective view of an upper column end. In the drawing 1 denotes an upright, tubular steel column and 2 a structural element fixed to the steel column in accordance with the invention. In figure 4 the upright tubular steel column is shown made up in the form of a square tube, but in an alternative embodiment is made of round tubing. An elongated member 3, an example of the design shape of which is shown in figure 3, is used for fixing. The said member comprises a substantially straight rod 3a and a plate 3b arranged at the bottom, and wires 3c arranged crosswise approximately at the middle of the rod for suspension and centring of the rod 3 a in the steel column 1. In the example embodiment according to figures 1 and 2 the columns are shown in cross-section along the centre and the wires 3c rest in triangular notches 8 with substantially straight sides, which meet at an angle, preferably on one side of the column, at a distance from the distal end of the column. The notch 8 is formed from the distal end of the column 1 in the longitudinal direction of the column and results in a 10-90% reduction of the distal surface, preferably one of approximately 50%. When the column 1 is placed on a plane surface, therefore, only parts of the original distal surface, preferably at the four corners of the column, will have contact with the plane surface, which reduces the possibility of sand, gravel and other material getting between the distal surface and the plane surface, which might give the column 1 an angle error. The notch 8 also serves as the space for the casting compound 4, which means full contact between the structural element and the column, even if sand, gravel or other material should be present in the space. The increased size of the notch 8 also increases the surface of the column end, which means that the column fixing is capable of bearing an increased load. In the example embodiment according to figure 1 the structural element is represented by an H-beam 2', which rests on the upper distal surface of the steel column. A space bounded at the bottom and the sides is defined substantially by the plate 3b and the inside of the column. In the space bounded at the bottom and the sides is a setting casting compound 4, intended to fix the rod 3 substantially centrally in the steel column 1 and to the structural element 2. Beams 10, such as roof trusses, joist elements or prefabricated concrete beams, for example, running transversely to the H- beam are generally placed on the H-beam 2'. The structural element is further exemplified in figure 2 by a cast slab 2", for example one of concrete for a floor in a multi-storey building. The slab 2" largely corresponds to structural element in figure 1. Between the slab 2" and the column 1 there is a load- spreading pad 6, the function of which is to distribute forces in the cast slab 2", which is preferably reinforced with reinforcing rods 7. The setting casting compound of the slab 2" is joined, at an opening 5" passing through the load-spreading pad 6, to the casting compound in the aforementioned space bounded at the bottom and the sides, forming one unit. In a further embodiment (not shown) the load-spreading pad also has parts, extending vertically and corresponding to the thickness of the cast slab 2'', for operatively connecting the steel column, substantially by means of steel, to other steel structures located on the slab 2". In the above-mentioned floor in a multi-storey building the column 1 ' of the next floor is connected to the structural element 2 from above. An extremity of the first part of the elongated member 3 extends above the structural element 2 and forms part of the fixing for this column 1 '. The extremity of the member 3 is closely surrounded by a casting compound 4', which during fixing is retained in a space formed by the bottom end of the said column 1 ', the structural element 2 and a mould fixing collar 11 that abuts the structural element 2 and the column 1 '. A through-opening 9' in the column is arranged at a distance above the end of the column in order to allow casting compound 4' to be introduced into the space, and subsequently forms a passage for wires or pipes. A facility for adjusting the column fixing along the upper surface of the structural element 2 is provided in that the extremity of the member 3 need not be situated in the middle of the bottom end of the column 1 ', since the inside of the column end 1 ' is many times greater than the extremity of the member 3, which provides a certain width tolerance. The mould fixing collar 11 is designed to hold the columns 1 and 1 ' in the fixing position and to cover the notch, so that the casting compound 4 is retained in the space when fixing, and is used both above and below the structural element 2 when connecting the columns 1 and 1 '. The collar 11 is made of plastic or other material that can easily be fixed by means of nails or the like to the structural element 2 or the casting mould (not shown) for the structural element. The collar 11 is furthermore designed with straight sides so that it can be aligned in relation to other collars (not shown) in the same plane.

Claims: Claims 1. Device for fixing a structural element (2) to the end of an upright, tubular steel column (1), characterised in that the device comprises an elongated member (3) with a first part of the length of the member outside the column and a second part inside the latter, that in the column there are means (3b) designed, together with the walls of the column (1), to define a space open at the top for a setting casting compound (4), intended for fixing the second part of the member (3) in the column (1), at least the aforementioned first part of the elongated member (3) being designed to achieve fixing of the structural element (2). 2. Device according to claim 1, characterised in that the casting compound (4) in the space is connected to a casting compound outside the column (1) 3. Device according to either of the preceding claims, characterised in that means (3c and 8) are provided for centring the second part of the elongated member (3) in the column (1). 4. Device according to any of the preceding claims, characterised in that the elongated member (3) is operatively connected to the means (3b) designed, together with the walls of the column (1), to define the space. 5. Method for fixing a structural element (2) to the end of an upright, tubular steel column (1), characterised by the following measures: a space is defined in the end of the column (1) a second part of an elongated member (3) is located in the space the space is filled with casting compound (4), the member (3) being fixed by setting of the casting compound (4), the structural element (2) being fixed at last to a first part of the elongated member (3). 6. Method according to claim 5, characterised in that the elongated member (3) is allowed to project above the structural element (2) on top of the column (1). 7. Method according to claim 5, characterised in that a further upright, tubular steel column on top of the structural element (2) is fixed by means of a casting compound to an extremity of the first part of the member (3). 8. Method according to any of claims 5 to 7, characterised in that a load- distributing pad (6) is placed on the steel column tube (1).

Inventors: JOHANSSON WILLY, LAKOMAA ANSSI, JOHANSSON, WILLY, LAKOMAA, ANSSI
Applicants: JOHANSSON WILLY, LAKOMAA ANSSI, JOHANSSON, WILLY, LAKOMAA, ANSSI
Application year: 2000
Main classification: E04B1
IPC codes: E04B1