FI20245215A1

FI20245215A1 - STEEL BEAM AND METHOD FOR PRODUCING A STEEL-CONCRETE JOINT BEAM

Info

Publication number: FI20245215A1
Application number: FI20245215A
Authority: FI
Inventors: Juuso Salonen; Esa Rusila; Heikki Jäämaa; Taru Leinonen
Original assignee: Peikko Group Oy
Priority date: 2021-08-20
Filing date: 2022-08-16
Publication date: 2024-02-22
Also published as: WO2023021238A1

Abstract

Presented is a steel beam (1) arranged to serve together with concrete as a bearing composite structure for various slab systems. The steel beam (1) comprises a base plate (2) and a beam part (3). The base plate (2) and the beam part (3) are connected together so that a space (4) for concrete is formed between the base plate (2) and the beam part (3), The base plate (2) is provided with a plurality of apertures (5) for forming passages from said space (4) through the base plate (2) to the outside of the steel beam (1) so that said space (4) is in fluid connection with an exterior of the steel beam (1) via said plurality of apertures (5) in the base plate (2).

Description

STEEL BEAM AND METHOD FOR PRODUCING A STEEL-CONCRETE

COMPOSITE BEAM

Field of the invention

The invention relates to a steel beam as defined in the preamble of independent claim 1.

The invention also relates to a method for producing a steel-concrete composite beam as defined in claim 36.

Publication WO 03/100186 presents a steel beam according to the preamble of independent claim 1.

Publication EP 3 332 932 presents a beam, which comprises a bottom plate, two web plates and a top plate, which define a space, which can be filled with concrete. A pipe is arranged in the space, through which pipe's wall moisture is arranged to transfer from the outside of the pipe to the inside of the pipe, and which pipe is arranged to be in the flow contact with the outside of the space for transferring moisture along the pipe to the outside of the space.

Publication GB 2 017 725 presents a system of construction thin shutters with mechanical in addition to frictional, bonding formations are provided for keying to infilling materials ranging from suitably hardening soils, with or without fibrous content, insulating materials, mortars, to additionally reinforced concretes for structural members. The densely distributed bonding formations consist of perforations and associated projections with enlarged ends formed by punching or otherwise to form mainly mechanical anchorage in the infilling material and automatic cover to any additional reinforcement. These shutters may be used for the construction of walls, lintels, beams, columns and floors.

Publication KR 10-1589866 presents a story height reducing beam for a slab construction, which can be conveniently produced by bending and foaming, can be constructed without constraints of a slab shape, can be constructed by allowing a level difference in a slab, and can greatly reduce a story height. According to a preferable embodiment of the present invention, the

S beam, in which a concrete filling hole in the shape of an inverted triangle at a central part is & provided, is composed of: an upper plate having a certain width in the longitudinal direction; left

N and right tilted webs extended by being downwardly bent with the same or different acute angles

N 30 at both ends of the upper plate; and a left and a right planar slab supporter horizontally extended

I by being bent to a side at the bottom of the left and the right tilted web. a

O Objective of the invention

O The object is to provide a steel beam having an improved ability to remove moisture from

N 35 — concrete that is cast into a space of the steel beam and correspondingly to provide a method for

N producing a steel-concrete composite beam having an improved ability to remove moisture from concrete of the steel-concrete composite beam.

Short description of the invention

The steel beam of the invention is characterized by the definitions of independent claim 1.

Preferred embodiments of the steel beam are defined in the dependent claims 2 to 35.

The method for producing a steel-concrete composite beam of the invention is correspondingly characterized by the definitions of claim 36.

Preferred embodiments of the method are defined in the dependent claims 37 to 40.

List of figures

In the following the invention will described in more detail by referring to the figures, of which

Figure 1 shows in partly transparent view a first embodiment of the steel beam,

Figure 2 shows the steel beam shown in figure 1 as seen from below,

Figure 3 shows the steel beam shown in figure 1 in cross-section,

Figure 4 shows in partly transparent view a second embodiment of the steel beam,

Figure 5 shows the steel beam shown in figure 4 as seen from below,

Figure 6 shows the steel beam shown in figure 4 in cross-section,

Figure 7 shows in partly transparent view a third embodiment of the steel beam,

Figure 8 shows the steel beam shown in figure 7 as seen from below,

Figure 9 shows the steel beam shown in figure 7 in cross-section,

Figure 10 shows in partly transparent view a fourth embodiment of the steel beam,

Figure 11 shows the steel beam shown in figure 10 as seen from below,

Figure 12 shows the steel beam shown in figure 10 in cross-section,

Figure 13 shows in partly transparent view a fifth embodiment of the steel beam,

Figure 14 shows the steel beam shown in figure 13 as seen from below,

Figure 15 shows the steel beam shown in figure 13 in cross-section,

Figure 16 shows in partly transparent view a sixth embodiment of the steel beam,

S Figure 17 shows the steel beam shown in figure 16 as seen from below, & Figure 18 shows the steel beam shown in figure 16 in cross-section,

N Figure 19 shows in partly transparent view a seventh embodiment of the steel beam,

N 30 Figure 20 shows the steel beam shown in figure 19 as seen from below, r Figure 21 shows the steel beam shown in figure 19 in cross-section, x Figure 22 shows in partly transparent view an eight embodiment of the steel beam,

O Figure 23 shows the steel beam shown in figure 22 as seen from below,

O Figure 24 shows the steel beam shown in figure 22 in cross-section,

N 35 Figure 25 shows in partly transparent view a ninth embodiment of the steel beam,

N Figure 26 shows the steel beam shown in figure 25 as seen from one side,

Figure 27 shows the steel beam shown in figure 25 as seen from below,

Figure 28 shows the steel beam shown in figure 25 as seen from above,

Figure 29 shows the steel beam shown in figure 25 in cross-section,

Figure 30 is a detail cross-section view of an aperture in the base plate of a steel beam,

Figure 31 shows in partly transparent view a tenth embodiment of the steel beam, and

Figure 32 shows the steel beam shown in figure 31 in cross-section.

Detailed description of the invention

First the steel beam 1 arranged to serve together with concrete as a bearing composite structure for various slab systems and some embodiments and variants of the steel beam 1 will be presented in greater detail.

The steel beam 1 comprises a base plate 2 and a beam part 3. The base plate 2 and the beam part 3 are made of steel.

The base plate 2 and the beam part 3 are connected together, preferably welded together, so that a space 4 for concrete (not illustrated) is formed between the base plate 2 and the beam part 3.

The base plate 2 is provided with a plurality of apertures 5 for forming passages from said space 4 through the base plate 2 to the outside of the steel beam 1 so that said space 4 is in fluid connection with an exterior of the steel beam 1 i.e. with the outside of the steel beam 1 via said plurality of apertures 5 in the base plate 2.

The purpose of said plurality of apertures 5 in the base plate 2 is to serve as passages for — moisture such as for vapor and/or for liquid and so to allow vapor and/or liquid from concrete that is cast into the space 4 of the steel beam 1 to move from the space 4 of the steel beam 1 to the outside of the steel beam 1 so as to promote drying of concrete that is cast into the space 4 of the steel beam 1.

The base plate 2 has preferably, but not necessarily, as in the embodiments of the steel — beam 1 shown in the figures and in detail in figure 30, a first surface 7 and a second surface 8 that is parallel with the first surface 7.

S If the base plate 2 of the steel beam 1 has a first surface 7 and a second surface 8 that is & parallel with the first surface 7, the first surface 7 of the base plate 2 is preferably, but not

N necessarily, essentially flat, as in the embodiments of the steel beam 1 shown in the figures. An

N 30 advantage of having a base plate 2 with an essentially flat first surface 7 is that it allows concrete r to flow more freely in the space of the steel beam 1 and so to allow better filling of the space 4 x with concrete. An advantage of having a base plate 2 with an essentially flat first surface 7 is that

O it provides for free i.e. unhindered flow of moisture from the concrete in the space 4 towards the

O plurality of apertures 5 in the base plate 2 of the steel beam 1. Supports (not illustrated) for

N 35 reinforcing rebars (not illustrated) to be arranged in the space 4 of the steel beam 1 and/or for

N positioning of the beam part 3 with respect to the base plate 2 can however be provided in the space 4 at the essentially flat first surface 7 of the base plate 2.

If the base plate 2 of the steel beam 1 has a first surface 7 and a second surface 8 that is parallel with the first surface 7, the first surface 7 of the base plate 2 is preferably, but not necessarily, free of projections extending from the first surface 7 of the base plate 2 into said space 4 at said plurality of apertures 5. An advantage of having a base plate 2 with a first surface 7 is that free of projections extending from the first surface 7 of the base plate 2 into said space 4 at — said plurality of apertures 5 is that it allows concrete to flow more freely in the space of the steel beam 1 and so to allow better filling of the space 4 with concrete. An advantage of having a base plate 2 is that free of projections extending from the first surface 7 of the base plate 2 into said space 4 at said plurality of apertures 5 is that it provides for free i.e. unhindered flow of moisture from the concrete in the space 4 towards the plurality of apertures 5 in the base plate 2 of the steel beam 1.. Supports for rebars to be arranged in the space 4 of the steel beam 1 and/or for positioning of the beam part 3 with respect to the base plate 2 can however be provided in the space 4 at the first surface 7 of the base plate 2.

If the base plate 2 of the steel beam 1 has a first surface 7 and a second surface 8 that is parallel with the first surface 7, the perimeter of at least 50 %, preferably at least 75 %, more preferably 100 % of said plurality of apertures 5 is preferably, but not necessarily, free of projections extending from said perimeter into said space 4. An advantage of having the perimeter at least 50 %, preferably at least 75 %, more preferably 100 % of said plurality of apertures 5 free of projections extending from said perimeter into said space 4 is that it allows concrete to flow more freely in the space of the steel beam 1 and so to allow better filling of the space 4 with concrete. An advantage of having the perimeter at least 50 %, preferably at least 75 %, more preferably 100 % of said plurality of apertures 5 free of projections extending from said perimeter into said space 4 is that it provides for free i.e. unhindered flow of moisture from the concrete in the space 4 towards the plurality of apertures 5 in the base plate 2 of the steel beam 1.

In the embodiments of the steel beam 1 illustrated in figures 1 to 15, 19 to 24, 31 and 32, — said plurality of apertures 5 extend, as illustrated in detail in figure 30, between the first surface 7 and the second surface 8 of the base plate 2 so that at least one aperture 5 of said plurality of a apertures 5, more preferably each of said plurality of the apertures 5, have an inlet 9 at the first & surface 7 of the base plate 2 i.e. at the space 4 of the steel beam 1 and an outlet 10 at the second

N surface 8 of the base plate 2 i.e. at the outer surface of the steel beam 1, and so that in said at least

N 30 one aperture 5 of said plurality of apertures 5, the inlet 9 and the outlet 10 of said at least one r aperture 5 of said plurality of apertures 5 is formed of material of the base plate 2, and so that the x first surface 7 of the base plate 2 partly limiting the space 4 for concrete and so that the second

O surface 8 forming a part of an outer surface (not marked with a reference numeral) of the steel

O beam 1.

N 35 In the steel beam 1, moisture is preferably, but not necessarily, arranged to transfer from

N said space 4 to the exterior of the steel beam 1 through said plurality of apertures 5 in the base plate 2.

In the steel beam 1, said plurality of apertures 5 in the base plate 2 are preferably, but not necessarily, free of tubes or the like arranged at least partly or partly in said plurality of apertures 5 in the base plate 2.

In the steel beam 1, said the space 4 is preferably, but not necessarily, in direct fluid communication with the exterior of the steel beam 1 via said plurality of apertures 5 in the base 5 plate 2.

The beam part 3 of the steel beam 1 comprises preferably, but not necessarily, as illustrated in the figures, two web plates 11 and a top plate 12. The two web plates 11 and the top plate 12 can be welded together to form the beam part 3. Alternatively can the two web plates 11 and the top plate 12 be formed of a single steel sheet that is bent so that a beam part 3 having two web plates 11 and a top plate 12 is formed.

If the beam part 3 of the steel beam 1 comprises two web plates 11 and a top plate 12, at least one of the two web plates 11 is preferably, but not necessarily, provided with openings 16 configured to allow concrete in fluid form to flow through the apertures 5 into the space 4 of the steel beam 1 from the outside of the space 4 of the steel beam 1. The web plates 11 and/or the top plate 12 can additionally be provided with air openings 18 dimensioned to allow air to escape from the space 4 of the steel beam 1 in connection with the filling of the space 4 of the steel beam 1 with concrete.

If the beam part 3 of the steel beam 1 comprises two web plates 11 and a top plate 12, at least one of the two web plates 11 is preferably, but not necessarily, inclined with respect to the base plate 2.

One of the two web plates 11 can, as illustrated in the tenth embodiment of the steel beam 1 illustrated in figures 31 and 32, extend perpendicularly from the base plate 2 and be unprovided with openings 16 configured to allow concrete in fluid form to flow through the apertures 5 into the space 4 of the steel beam 1 from the outside of the space 4 of the steel beam 1. Said one of the — two web plates 11 that is unprovided with openings 16 configured to allow concrete in fluid form to flow through the apertures 5 into the space 4 of the steel beam 1 from the outside of the space 4

S of the steel beam 1 can however be provided with air openings 18 dimensioned to allow air to & escape from the space 4 of the steel beam 1 in connection with the filling of the space 4 of the steel

N beam 1 with concrete.

N 30 If the beam part 3 of the steel beam 1 comprises two web plates 11 and a top plate 12, the r two web plates 11 are preferably, but not necessarily, attached to the base plate 2 so that the base x plate 2 having between the web plates 11 areas (not marked with a reference numeral) free of said

O plurality of apertures 5, and so that by said areas free of said plurality of apertures 5 being at the

O web plates 11 so that said plurality of apertures 5 are provided between said areas free of said

O 35 plurality of apertures 5.

If the beam part 3 of the steel beam 1 comprises two web plates 11 and a top plate 12, the two web plates 11 are preferably, but not necessarily, attached to the base plate 2 so that at least one flange 6 for supporting an end of at least one hollow-core slab (not illustrated) is formed at the base plate 2 outside the space 4. The embodiments of the steel beam 1 illustrated in figures 1 to 28 have two flanges 6 and the embodiment of the steel beam 1 illustrated in figures 31 and 32 has one flange 6.

If the beam part 3 of the steel beam 1 comprises two web plates 11 and a top plate 12, the beam part 3 comprises preferably, but not necessarily, an end plate 17 at each opposite end of the steel beam 1.

The number of apertures 5 in said plurality of apertures 5 through the base plate 2 is preferably, but not necessarily, at least 3, more preferably at least 10.

Said plurality of apertures 5 through the base plate 2 are preferably, but not necessarily, — arranged in a pattern that comprises at least one row of apertures 5, which said at least one row of apertures extend in a longitudinal direction of the steel beam 1. The apertures are preferably, but not necessarily, distributed essentially evenly in each row of apertures 5 so as to allow moisture effectively to escape from concrete in the space 4 of the steel beam 1 over the whole length of the steel beam 1. The number of apertures 5 in each row of apertures 5 is preferably, but not necessarily, at least 3, more preferably at least 10. The number of rows can for example be 2 to 10, such as 3 to 9 or 4 to 8 or 5 to 7 or 5 to 6.

The number of apertures 5 is preferably, but not necessarily, between 5 and 25 per sguare meter, such as between 10 and 20 per sguare meter, for example about 15 per sguare meter. The selected number of apertures per sguare meter can depend on the size of the apertures 5. — Said plurality of apertures 5 through the base plate 2 are preferably, but not necessarily, arranged in a pattern that comprises several rows of apertures 5 so that the rows of apertures 5 extend in parallel. The apertures are preferably, but not necessarily, distributed essentially evenly in each row of apertures 5. The number of apertures 5 in each row of apertures 5 is preferably, but not necessarily, at least 3, more preferably at least 10. The number of rows can for example be 2 to 10,such as 3 to 9 or 4 to 8 or 5 to 7 or 5 to 6. The individual apertures 5 in adjacent rows of apertures 5 are preferably, but not necessarily, in the longitudinal direction of the steel beam 1

S arranged at least partly transversally offset from one row of apertures 5 to the adjacent row of & apertures 5 in the transversal direction of the steel beam 1 as in the embodiments illustrated in

N figures 1 to 12 and 19 to 24 and 30 to 32 so as to make the base plate 2 stronger and to avoid

N 30 unnecessary weakening of the base plate 5 by providing apertures 5 through the base plate 2. An r aperture 5 in a row of apertures 5 is preferably, but not necessarily, at most only partly aligned x with an aperture 5 in an adjacent row of apertures 5 as in the embodiments illustrated in figures 1

O to 12 and 19 to 24 and 30 to 32 so as to make the base plate 2 stronger and to avoid unnecessary

O weakening of the base plate 5 by providing apertures 5 through the base plate 2. The apertures 5

N 35 in at least one row of apertures 5 is preferably, more preferably in each row of apertures 5, spaced

N apart in the longitudinal direction of the steel beam 1 by a distance that is a least the extension of the individual apertures 5 in the longitudinal direction of the steel beam 1 as in the embodiments illustrated in the figures so as to make the base plate 2 stronger and to avoid unnecessary weakening of the base plate 5 by providing apertures 5 through the base plate 2. No aperture 5 is preferably, but not necessarily, fully aligned with an aperture 5 in an adjacent row of apertures 5 as in the embodiments illustrated in figures 1 to 12 and 19 to 24 and 30 to 32 so as to make the base plate 2 stronger and to avoid unnecessary weakening of the base plate 2 by providing apertures 5 through the base plate 2. No aperture 5 is preferably, but not necessarily, fully aligned with an aperture 5 in another row of apertures 5 in the longitudinal direction of the steel beam 1. A purpose of such arrangement of the apertures is to avoid unnecessary weakening of the base plate 2 of the steel beam 1 by avoiding having apertures 5 of different rows of apertures 5 exactly at the same location in the longitudinal direction of the steel beam 1. Each aperture 5 of the plurality apertures 5in any of the rows of apertures 5 is preferably, but not necessarily, at most only partly aligned with any aperture 5 of the plurality apertures 5 in any other of the rows of apertures 5 in the longitudinal direction of the steel beam 1. A purpose of such arrangement of the apertures is to avoid unnecessary weakening of the base plate 2 of the steel beam 1 by avoiding having apertures 5 of different rows of apertures 5 at the same location in the longitudinal direction of the steel — beam 1, as in the eighth embodiment of the steel beam 1 illustrated in figures 22 to 24 and in the tenth embodiment of the steel beam 1 illustrated in figures 31 to 32. Each aperture 5 of the plurality of apertures 5 in any of the rows of apertures 5 is preferably, but not necessarily, completely unaligned with any aperture 5 of the plurality of apertures 5 in any of the other rows of apertures 5 in the longitudinal direction of the steel beam 1. A purpose of such arrangement of the apertures is to avoid unnecessary weakening of the base plate 2 of the steel beam 1 by avoiding having apertures 5 of different rows of apertures 5 at the same location in the longitudinal direction of the steel beam 1, as in the first embodiment of the steel beam 1 illustrated in figures 1 to 3, in the second embodiment of the steel beam 1 illustrated in figures 4 to 6, in the fourth embodiment of the steel beam 1 illustrated in figures 10 to 12, and in the seventh embodiment of the steel beam 1 illustrated in figures 19 to 21.

Said plurality of apertures 5 through the base plate 2 are preferably, but not necessarily,

S spaced by regular intervals between the opposite ends of the steel beam 1 so as to allow moisture & effectively to escape from concrete in the space 4 of the steel beam 1 over the whole length of the

N steel beam 1.

N 30 The cross-section area of an individual apertures 5 through the base plate 2 can be between

I 50 mm? and 5000 mm?, such as between 75 mm? and 1500 mm”. x At least one aperture of said plurality of apertures 5 can have one of a round configuration

O and an elongated configuration.

O The apertures 5 in said plurality of apertures 5 through the base plate 2 of the steel beam 1

O 35 — are preferably, but not necessarily, provided essentially evenly between opposite ends of the steel beam 1 so as to allow moisture effectively to escape from concrete in the space 4 of the steel beam 1 over the whole length of the steel beam 1.

At least one perforated channel element 13 can, as in the sixth embodiment of the steel beam 1 illustrated in figures 16 to 18 and in the ninth embodiment of the steel beam 1 illustrated in figures 25 to 29, be provided inside the space 4 of the steel beam 1 so that said at least one perforated channel element 13 is in fluid connection with the space 4 of the steel beam 1 and in fluid connection with said plurality of apertures 5 in the base plate 2 of the steel beam 1 so as to enhance drying of concrete in the space 4 of the steel beam 1. Said at least one perforated channel element 13 is configured to form a space section 14 in the space 4 of the steel beam 1 and is configured to prevent concrete that is cast into the space 4 of the steel beam 1 from entering the space section 14. Vapor and/or liquid from concrete that is cast into the space 4 of the steel beam 1 will move to the exterior of the steel beam 1 by firstly move from concrete that is cast into the space 4 of the steel beam 1 through the perforated channel element 13 into the space section 14 and from the space section 14 through at least one of said plurality of apertures 5 in the base plate 2 of the steel beam 1 to the exterior of the steel beam 1.

If at least one perforated channel element 13 is provided inside the space 4 of the steel beam 1, as presented, one perforated channel element 13 can be attached to the base plate 2 of the — steel beam 1 along the length of said one perforated channel element 13.

If at least one perforated channel element 13 is provided inside the space 4 of the steel beam 1, as presented, one perforated channel element 13 can, as in the sixth embodiment of the steel beam 1 illustrated in figures 16 to 18, be in the form of an open-sided perforated channel element that is attached to the base plate 2 and that limits a space section 14 together with the base plate 2 of the steel beam 1 in the space 4 of the steel beam 1, which space section 14 is in fluid communication with the exterior of the steel beam 1 via apertures 5 in the base plate 2 of the steel beam 1. Said at least one perforated channel element 13 will prevent concrete that is cast into the space 4 of the steel beam 1 from entering the space section 14.

If at least one perforated channel element 13 is provided inside the space 4 of the steel — beam 1, as presented, and if the beam part 3 of the steel beam 1 comprises two web plates 11 and a top plate 12, as presented, one perforated channel element 13 can, as in the ninth embodiment of a the steel beam 1 illustrated in figures 25 to 29, be attached between the base plate 2 of the steel & beam 1 and the top plate 12 of the steel beam 1.

N If at least one perforated channel element 13 is provided inside the space 4 of the steel

N 30 beam 1, as presented, the space 4 can additionally be in direct fluid communication with the r exterior of the steel beam 1 via said plurality of apertures 5 in the base plate 2. & The steel beam 1 can, as in the seventh embodiment of the steel beam 1 illustrated in figures

O 19 to 21 and in the eight embodiment of the steel beam 1 illustrated in figures 22 to 24, be provided

O with at least one closing member 15 that is attached to the steel beam 1 and that is configured to

O 35 close at least partly at least one aperture of said plurality of apertures 5. Said at least one closing member 15 can, as in the seventh embodiment of the steel beam 1 illustrated in figures 19 to 21, be attached to the base plate 2 inside the space 4 of the steel beam 1, or be attached to the base plate 2 outside the space 4 of the steel beam 1 as in the eight embodiment of the steel beam 1 illustrated in figures 22 to 24. Said at least one closing member 15 can additionally or alternatively be provided at least partly in at least one aperture 5 of said plurality of apertures 5.

If the steel beam 1 is provided with at least one closing member 15, said at least one closing member 15 can comprise semipermeable material. It is also possible that said at least one closing member 15 can comprise impermeable material and that said at least one closing member 15 is intended to be removed when the concrete in the space 4 of the steel beam 1 has hardened to a sufficient degree so that there is no risk that matter in other phase form than vapor can pass from the space 4 of the steel beam 1 through said plurality of apertures 5 in the base plate 2 of the steel beam 1 to the outside of the steel beam 1.

If the steel beam 1 is provided with at least one closing member 15, said at least one closing member 15 can comprise water vapor-permeable, liquid-impermeable material so as to only permit vapor to pass through the closing member 15 and so as to prevent material in other phases to pass through the closing member 15.

If the steel beam 1 is provided with at least one closing member 15, said at least one closing member 15 can be removable attached to the steel beam 1 by at least one of an openable adhesive connection and an openable mechanical connection so as to allow, if so desired, to remove said at least one closing member 15.

If the steel beam 1 is provided with at least one closing member 15, said at least one member can comprise or be in the form of at least one of a rigid plate member and a flexible sheet — member.

The steel beam 1 can comprise at least one heating arrangement such as a heating cable provided in the space 4 for concrete so as to promote faster drying of the concrete in the space 4 for concrete.

Next the method for producing a steel-concrete composite beam and some embodiments — and variants of the method will be described in greater detail.

The steel-concrete composite beam can be in the form of a prefabricated steel-concrete

S composite beam that is produced off-site in a factory prior transportation and installation at a & building site or in the form of a steel-concrete composite beam that is partly produced on-site at a

N building site. In other words, in case of off-site production, a prefabricated steel-concrete

N 30 — composite beam is casted before it is installed to a final location in a building. Casting is typically r done in precast factory in controlled conditions. The prefabricated steel-concrete composite beam x is transported to building site after concrete is hardened enough to stand the lifting and

O transportation action. In case of on-site production of the steel-concrete composite beam, a steel

O beam 1 is initially provided and installed to final location in the building and casted either before,

N 35 — together or after installing of slabs such as hollow-core slabs or other parts of the floor so that the

N steel-concrete composite beam is produced. It is also possible to do casting on-site eg. next to the building before prefabricated steel-concrete composite beam is installed to a final location in a building. The apertures 5 in the base plate 2 for drying will do their work despite if on-site or off-

site production of the steel-concrete composite beam is used.

A heating arrangement such as heating cables can be installed in the space 4 of the steel beam 1 if a need to dry the concrete in the space 1 of the beam 1 faster exists.

The method comprising providing a steel beam 1 according to any embodiment or variant — presented earlier in this text.

The method comprises a filling step for filling the space 4 of the steel beam 1 with concrete.

The filling step can be performed either off- or on-site as presented.

The method comprises a closing step for in an openable manner closing at least one aperture 5 of said plurality of apertures 5 at least partly with at least one closing member 15 prior feeding concrete into said space 4 in said filling step.

The closing step comprise in some embodiments and variants of the method attaching said at least one closing member 15 to the base plate 2 of the steel beam 1 outside the space 4 of the steel beam 1 by at least one of an openable adhesive connection and an openable mechanical connection so as to allow, if so desired, to remove said at least one closing member 15.

The method can comprise removing the closing member 15 after performing the filling step, preferable when the concrete has hardened to a sufficient degree.

The closing member 15 that is used in the method can comprise semipermeable material.

The closing member 15 that is used in the method can comprise water vapor-permeable, liguid-impermeable so as to only permit vapor to pass through the closing member 15 and so as to prevent material in other phases to pass through the closing member 15.

The closing member 15 that is used in the method can comprise or be in the form at least one of a rigid plate member and a flexible sheet member.

The method can comprise providing at least one heating arrangement such as a heating cable provided in the space 4 for concrete so as to promote faster drying of the concrete in the space 4 for concrete.

It is apparent to a person skilled in the art that as technology advanced, the basic idea of

S the invention can be implemented in various ways. The invention and its embodiments are

O . on: .

N therefore not restricted to the above examples, but they may vary within the scope of the claims.

N

2

N

I a a

O

N

LO

+

N

O

N

Claims

1. A steel beam (1) arranged to serve together with concrete as a bearing composite structure for various slab systems, wherein the steel beam (1) comprises a base plate (2) and a beam part (3), and wherein the base plate (2) and the beam part (3) are connected together so that a space (4) for concrete is formed between the base plate (2) and the beam part (3), characterized by the base plate (2) being provided with a plurality of apertures (5) for forming passages from said space (4) through the base plate (2) to the outside of the steel beam (1) so that said space (4) is in fluid connection with an exterior of the steel beam (1) via said plurality of apertures (5) in the base plate (2).

2. The steel beam (1) according to claim 1, characterized by the base plate (2) has a first surface (7) and a second surface (8) that is parallel with the first surface (7), by said plurality of apertures (5) extend between the first surface (7) and the second surface (8) so that at least one aperture of said plurality of apertures (5) have an inlet (9) at the first surface (7) and an outlet at the second surface (8), by said at least one aperture of said plurality of apertures (5), the inlet (9) and the outlet of said at least one aperture of said plurality of apertures (5) being formed of material of the base plate (2), and by the first surface (7) of the base plate (2) partly limiting the space (4) for concrete and by the second surface (8) forming a part of an outer surface of the steel beam (1).

3. The steel beam (1) according to claim 2, characterized N by the first surface (7) of the base plate (2) being essentially flat. N

N 4. The steel beam (1) according to claim 2 or 3, characterized N 30 by the first surface (7) of the base plate (2) being free of projections extending from the I first surface (7) of the base plate (2) into said space (4) at said plurality of apertures (5). a

O 5. The steel beam (1) according to any of the claims 2 to 4, characterized O by the perimeter of at least 50 %, preferably at least 75 %, more preferably 100 % of said O 35 M of apertures (5) being free of projections extending from said perimeter into said space

6. The steel beam (1) according to any of the claims 1 to 5, characterized by moisture is arranged to transfer from said space (4) to the exterior of the steel beam (1) through said plurality of apertures (5) in the base plate (2)

7. The steel beam (1) according to any of the claims 1 to 6, characterized by said plurality of apertures (5) in the base plate (2) are free of tubes or the like arranged in said plurality of apertures (5) in the base plate (2).

8. The steel beam (1) according to any of the claims 1 to 7, characterized by the space (4) is in direct fluid communication with the exterior of the steel beam (1) via said plurality of apertures (5) in the base plate (2).

9. The steel beam (1) according to any of the claims 1 to 8, characterized by the beam part (3) being formed by two web plates (11) and a top plate (12).

10. The steel beam (1) according to claim 9, characterized by at least one of the two web plates (11) being provided with openings (16) configured to allow concrete in fluid form to flow through the apertures (5) into the space (4) of the steel beam (1) from the outside of the space (4) of the steel beam (1).

11. The steel beam (1) according to any of the claims 1 to 10, characterized by the number of apertures (5) in said plurality of apertures (5) through the base plate (2) being at least 3, preferably at least 10.

12. The steel beam (1) according to any of the claims 1 to 11, characterized by said plurality of apertures (5) are arranged in a pattern that comprises at least one row a of apertures (5), which said at least one row of apertures extend in a longitudinal direction of the N steel beam (1). S N 30

13. The steel beam (1) according to any of the claims 1 to 12, characterized I by said plurality of apertures (5) are arranged in a pattern that comprises several rows of a apertures (5), and O by the rows of apertures extend in parallel. O N 35

14. The steel beam (1) according to claim 12 or 13, characterized N by the number of apertures (5) in each row of apertures (5) being at least 3, preferably at least 10.

15. The steel beam (1) according to any of the claims 12 to 14, characterized by an aperture (5) in a row of apertures (5) is at most only partly aligned with an aperture (5) in an adjacent row of apertures (5).

16. The steel beam (1) according to any of the claims 12 to 15, characterized by each aperture (5) of the plurality apertures (5) in any of the rows of apertures (5) being at most only partly aligned with any aperture (5) of the plurality apertures (5) in any other of the rows of apertures (5) in the longitudinal direction of the steel beam (1). —

17. The steel beam (1) according to any of the claims 12 to 15, characterized by each aperture (5) of the plurality of apertures (5) in any of the rows of apertures (5) being completely unaligned with any aperture (5) of the plurality of apertures (5) in any of the other rows of apertures (5) in the longitudinal direction of the steel beam (1).

18. The steel beam (1) according to any of the claims 12 to 17, characterized by the apertures (5) in at least one row of apertures (5), preferably in each row of apertures (5), being spaced apart in the longitudinal direction of the steel beam by a distance that is a least the extension of the individual apertures (5) in the longitudinal direction of the steel beam (1).

19. The steel beam (1) according to any of the claims 12 to 18, characterized by no aperture (5) is fully aligned with an aperture (5) in an adjacent row of apertures (5).

20. The steel beam (1) according to any of the claims 12 to 19, characterized by no aperture (5) is fully aligned with an aperture (5) in another row of apertures (5) in — the longitudinal direction of the steel beam (1). S

21. The steel beam (1) according to any of the claims 1 to 20, characterized & by at least one aperture of said plurality of apertures (5) having one of a round and an N elongated configuration. N 30 r

22. The steel beam (1) according to any of the claims 1 to 21, characterized x by the apertures (5) in said plurality of apertures (5) through the base plate (2) of the steel O beam (1) being provided essentially evenly between opposite ends of the steel beam (1). O N 35

23. The steel beam (1) according to any of the claims 1 to 22, characterized N by at least one perforated channel element (13) provided inside the space (4) of the steel beam (1), and by said at least one perforated channel element (13) being in fluid connection with the space (4) of the steel beam (1) and in fluid connection with said plurality of apertures (5) in the base plate (2) of the steel beam (1).

24. The steel beam (1) according to claim 23, characterized by one perforated channel element (13) being attached to the base plate (2) of the steel beam (1) along said one perforated channel element (13).

25. The steel beam (1) according to claim 22 or 23, characterized by one perforated channel element (13) being in the form of an open-sided perforated channel element that is attached to the base plate (2) and that limits a space section (14) together with the base plate (2) of the steel beam (1) in the space (4) of the steel beam (1).

26. The steel beam (1) according to any of the claims 23 to 25 and claim 9 or 10, characterized by one perforated channel element (13) being attached between the base plate (2) of the — steelbeam (1) and the top plate (12) of the steel beam (1).

27. The steel beam (1) according to claim 23 or 26, characterized by the space (4) is additionally in direct fluid communication with the exterior of the steel beam (1) via said plurality of apertures (5) in the base plate (2).

28. The steel beam (1) according to any of the claims 1 to 27, characterized by at least one closing member (15) attached to the steel beam (1) and configured to close at least partly at least one aperture (5) of said plurality of apertures (5).

29. The steel beam (1) according to claim 28, characterized by said at least one closing member (15) being attached to the base plate (2) inside the S space (4) of the steel beam (1). & N

30. The steel beam (1) according to claim 29, characterized N 30 by said at least one closing member (15) being attached to the base plate (2) outside the I space (4) of the steel beam (1). a O

31. The steel beam (1) according to any of the claims 28 to 30, characterized O by said at least one closing member (15) being provided at least partly in at least one O 35 aperture of said plurality of apertures (5).

32. The steel beam (1) according to any of the claims 28 to 31, characterized by said at least one closing member (15) comprising water vapor-permeable, liguid-

impermeable material.

33. The steel beam (1) according to any of the claims 28 to 32, characterized by said at least one closing member (15) being removable attached to the steel beam (1) by atleast one of an openable adhesive connection and an openable mechanical connection.

34. The steel beam (1) according to any of the claims 28 to 33, characterized by said at least one closing member (15) comprising at least one of a rigid plate member and a flexible sheet member.

35. The steel beam (1) according to any of the claims 1 to 34, characterized by at least one heating arrangement such as a heating cable provided in the space (4) for concrete.

36. A method for producing a steel-concrete composite beam, characterized by the method comprising providing a steel beam (1) according to any of the claims 1 to 35, by a filling step for filling the space (4) of the steel beam (1) with concrete, and by a closing step for in an openable manner closing at least one aperture of said plurality of apertures (5) at least partly with at least one closing member (15) prior feeding concrete into said space (4) in said filling step.

37. The method according to claim 36, characterized by attaching said at least one closing member (15) to the base plate (2) of the steel beam (1) outside the space (4) of the steel beam (1) by at least one of an openable adhesive connection S and an openable mechanical connection. & N

38. The method according to claim 36 or 37, characterized N 30 by removing said at least one closing member (15) after performing the filling step. x a

39. The method according to any of the claims 36 to 38, characterized O by the removable closing member (15) that is used comprising water vapor-permeable, O liguid-impermeable O 35

40. The method according to any of the claims 36 to 39, characterized by said at least one removable closing member (15) comprising at least one of a rigid plate member and a flexible sheet member.