FI96711B - Bar reinforcement for concrete constructions and combined constructions - Google Patents

Abstract

The starting material 1 for the bar reinforcement comprises one or more panel-like sections or one or more ridge-like profiles. The bar reinforcement has a middle section 3 and two projections 4 which issue at an angle from its ends and which are intended to be connected to a building part for connecting the said part to concrete. The projections 4 are at least substantially inclined in relation to the shearing stress directed towards the construction comprising the bar reinforcement. <IMAGE>

Description

96711

Bonding for concrete and composite structures. -Stagarmering för betongkonstruktioner och samkonstruktioner.

The invention relates to a bonding reinforcement for concrete structures and composite structures. The joint structure can be a steel-concrete, concrete-concrete or wood-concrete joint structure.

The invention relates to concrete construction. Concrete is a material) with good adhesion properties, while it cracks with very low tensile stresses. Traditionally, the tensile stress-transmitting parts of a concrete structure are reinforced with steel bars (reinforced concrete) or the concrete is bonded to a tensile stress-transmitting steel structure (steel-concrete composite-15 structure). In the former case, the compressive concrete structure is connected to the tensile steel bars by hook reinforcement, in the latter case the concrete is attached to the steel structure by dowels. In the early days of concrete construction, these bonding reinforcements were round bars with 20 ends bent to anchor the bars. As the manufacturing technology developed, reinforced concrete bars with brushed surfaces were used in reinforced concrete structures, which got rid of anchoring bends. Correspondingly, various automatically welded dowel pins were developed in the composite structures, e.g. EP patent 0 469 337. Recently, several different steel beams used in the composite structures have been further developed, which structural measures have been used to avoid the use of extra dowel pins, e.g. FI patents 848 and 85745. The concrete-30 concrete joint structure is formed by embedding U-hooks bent from reinforcing steel in a concrete element beam. An obstacle to the use of a wood-concrete joint structure has been e.g. lack of a suitable stake.

The object of the invention is to provide a simple reinforcement which can be used in a variety of ways for the transmission of shear and thrust forces and which is suitable for use in all the above-mentioned applications.

2 96711 This object is solved according to the invention in such a way that the bonding reinforcement according to the invention is characterized in that the bonding reinforcement is formed by one or more plate-like bodies or one or more trough-shaped profiles, that the bonding reinforcement comprises an intermediate part and two angled projections to be joined to the component for connecting said component to the concrete, and that the projections are arranged at least substantially obliquely to the main shear stress on the structure containing the bonding reinforcement.

From a manufacturing point of view, this is advantageously achieved by cutting straight or different-shaped webs from 15 sheets, which can be bent into a U-shape in the way best suited to the application. It is also possible to use, for example, an L-U or semicircular profile as the starting blank, or this shape can be obtained in connection with the production of a bonding reinforcement. The reinforcement according to the invention can also be made in a closed form by deep-drawing it from a metal plate. Particularly in the production of large bonding reinforcements, it is advantageous to assemble them from parts using a known technique, e.g. by welding.

Other preferred embodiments of the invention are set out in the subclaims.

The advantage of the reinforcement according to the invention is, above all, that the stiffness properties of the bonding reinforcement can be modified very easily by the width of the piece and the bending angles. The advantage of the plate structure is still easy weldability. Automatic welding, such as butt welding, can advantageously be applied to the optimized, small steel cross-sectional area. It further follows from the cross-sectional optimization that the bonding reinforcement 35 can be welded to the thin-flanged steel profile. The bonding reinforcement can also be fixed with glue, self-drilling screws or firing nails. When screws or nails are used, the bonding reinforcement is provided for this purpose 3 96711 with holes either in the lower flange of the closed profile or in the transverse projection in the bonding reinforcement. Side-5 reinforcement can also be attached to the perforated anchoring section.

A U-shaped bonded reinforcement or a conical compressed closed profile is still advantageous for storage and transport, as the reinforcements can be stacked on top of each other. The reinforcement according to the invention can easily be shaped so that it remains upright on a horizontal surface without support, which facilitates welding work on a composite structure construction site.

Unlike previous structures, the invention can be applied as a shear reinforcement for a reinforced concrete structure, as a structural truss part of a steel structure as well as as a dowel for a steel-concrete, concrete-concrete or wood-concrete joint structure.

The invention will now be described in more detail with reference to the preferred embodiments of the invention shown in the accompanying drawings.

Figures 1-5 show examples of bond reinforcements according to the invention, with the figures marked a: 11a showing the reinforcement seen directly from the front, the figures marked b marked with the reinforcement "* from the side and the figures marked c showing the starting material of the reinforcement.

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Figure 6a shows the use of reinforcement as a stud in a steel-concrete joint beam seen from the side.

Fig. 6b shows a section along the line VI-VI in Fig. 6a. 35

Figure 7a shows a side view of a steel beam used in a composite structure.

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Fig. 7b shows a section along the line VII-VII in Fig. 7a.

Fig. 8a shows a side view of a reinforced concrete beam in which the bonding reinforcement according to the invention is connected to the support during the installation of the intermediate base elements.

Fig. 8b shows a section along the line 10 VIII-VIII in Fig. 8a.

Figure 9a shows a side view of a bonding reinforcement according to an embodiment of the invention.

Fig. 9b shows a section along the line IX-IX in Fig. 9a.

Figures 1 to 5 show examples of a bonding reinforcement according to the invention for concrete structures and composite structures. The bonding reinforcement according to the invention is formed by 20 plate-like bodies 1 bent at at least two points 2 so as to form an intermediate part 3 and two protruding projections 4 angled at its ends.

When using the straightforward bends indicated by the reference numeral 2 in the starting blanks shown in Figs. 1c to 4c, the starting blank 1 is formed by a planar and flat plate straight sheet web. Depending on the desired angles * · ·· .. ·· for the bonding reinforcement, the bundle blank 1 may also be formed by a planar sheet web comprising a central web portion 3 and side web portions 4 projecting at an angle from both ends of the sheet 4. When cutting the starting blank 1 from the sheet, that the longitudinal sides 5, 6 of the middle web part 3 are of the same length.

If necessary, the protruding parts 4 of the bonding reinforcement can further be connected by one or more additional intermediate parts, as shown in the application example of the bonding reinforcement shown in Figs. 5a and 5b, in which the bonding reinforcement is formed by deep drawing.

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The reinforcement according to the invention is thus produced by cutting a straight or other web from the sheet, which is bent or deep-drawn in the desired manner. The stiffness properties of the reinforcement can be easily modified by changing the width of the plate web and the bending angles between the intermediate part 3 and the protruding parts 4.

If necessary, the intermediate part 3 can be formed common to several, usually more than two cantilever parts 4 (not shown).

In addition to the projections 4, the intermediate part or parts 3 can also be arranged at least substantially obliquely to the main shear stress on the structure containing the bonding reinforcement.

In order to facilitate the connection of the bonding reinforcement to the structural part, it is in some cases advantageous to provide the free ends 20 of the protruding parts 4 with a transverse protrusion (not shown).

Figures 6a and 6b show a steel-concrete joint beam, in which the reinforcement according to the invention binds the concrete 7 to the steel structure 8. As the joint structure bends, the concrete 7 tends to slide away from the steel structure 8, the concrete 7 protruding against the reinforcement according to the invention. As the concrete 7 is pressed against the reinforcement, it tends to rise out of the steel-concrete joint.

30 The number and location of the reinforcements are dimensioned according to these thrust forces acting on the reinforced concrete sliding surface. By bending the intermediate part 3 and the protruding parts 4 of the bonding reinforcement to different angles, both the bending stiffness of the reinforcement and the local compressive stress 35 on the concrete 7 can be easily adjusted. By increasing the reinforcing surface acting against the thrust, the compressive stresses of the concrete 7 can be reduced. Correspondingly, the stiffness of the reinforcement against the bending stress caused by the thrust forces decreases when the protruding parts 4 of the bonding reinforcement are thus bent.

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The high compressive stresses on the concrete acting against the reinforcement tend to be distributed in the surrounding concrete, 5 while causing lateral splitting forces. By means of the oblique surfaces of the cantilever parts 4 and also of the intermediate parts 3, these splitting forces acting on the concrete 7 can be largely transmitted through the closed inner surface of the curb, the intermediate part 3 keeping the concrete in size despite large creep forces 10 even near the concrete slab edge. At the same time, the intermediate part 3 prevents the concrete structure from rising off the surface of the steel structure.

In general, freely supported joint beams aim to use the rigidest joints possible, thus minimizing their number. However, in continuous structures, the forces due to shrinkage and thermal movements of the concrete must also be taken into account, in which case it is advantageous to use more flexible bonding solutions that can reduce the cracking of the concrete caused by forces. In such cases, the stiffness of the bonding reinforcement according to the invention can be easily adjusted, e.g. by changing the bending angles.

Figures 7a and 7b show a steel beam 25 8 of a composite structure, on which the intermediate floor elements are installed on a construction site. In connection with the joint casting of the elements, the steel beam is cast inside the concrete 7, whereby the bonding reinforcement acts as a dowel structure, by means of which the steel beam 8 and the cast concrete 7 are made to work together. The reinforcement toi-30 according to the invention acts as a dowel both for the cantilever parts 4 and, above all, for the intermediate parts 3, where the compressive stresses resulting from the bending of the composite structure in concrete are greatest. In the preferred embodiment according to the figure, the reinforcement according to the invention increases the bending stiffness of the steel beam 35 during the installation of the intermediate floor elements by forming a continuous lattice structure on the sides of the steel beam 8.

Figures 8a and 8b show a reinforced concrete structure in which the reinforcement according to the invention acts both as a beam shear reinforcement and as an anchor for a load-bearing jaw structure during the installation of intermediate floor elements. The beam compression-side reinforcement 5 is attached to the invention siderau-doitteisiin. The reinforced concrete beam is otherwise reinforced and manufactured using known techniques.

The starting blank 1 of the bonding reinforcement can be one or more plate-like bodies or one or more trough-shaped profiles, such as an L-U or a semicircular profile. In the application example shown in Figs. 9a and 9b, the bonding reinforcement is formed by bending a starting blank formed by a planar and flat plate straight sheet web. In this case, the starting blank 15 can also be formed by an L-profile.

The advantage of the bond reinforcement shown in Figs. 9a and 9b is that the bond reinforcement thus formed acts in the same manner with respect to both directions of the main shear stress applied to the structure containing the bond reinforcement. It should be noted that such a structure is also achieved by suitably joining together two bonding reinforcements, e.g. according to Fig. 4.

The application examples presented above are not intended to limit the invention in any way, but the invention can be applied completely freely within the scope of the claims.

Thus, it is clear that the bonding reinforcement according to the invention can be used, for example, when anchoring the fastening plates to concrete or by transferring high shear forces in cantilever structures. The shear reinforcement according to Fig. 8 can also be anchored in other ways than by welding to the jaw structure. For example, the free ends of the protruding parts 4 of the bonding reinforcement can be provided with pins or transverse protrusions 35.

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Claims (10)

Stag reinforcement for concrete structures and co-structures, characterized in that the starting material (1) for the stag reinforcement is one or more slab-like pieces or one or more slat-like profiles, that the stag reinforcement has an intermediate piece (3) and protrudes from its ends at an angle. projecting portions (4), which projecting portions are intended to be connected to a building portion for connecting said building portion to concrete, and that the projecting portions (4) are at least substantially obliquely arranged in relation to the intersection stress which is directed to the staggering structure within. Stag reinforcement according to Claim 1, characterized in that the starting material (1) is formed by a pian and evenly straight disc web. 3. Stag reinforcement according to claim 1 or 2, characterized in that the starting material (1) is formed by a pianous sheet web comprising a middle web piece forming said intermediate piece (3) and from its two ends at angular projections. , forming said protrusions (4). 25 4. Stag reinforcement according to claim 3, characterized in that the longitudinal sides (5, 6) of the middle web piece (3) are the same length. Stag reinforcement according to claim 1, characterized in that the protruding parts (4) are additionally provided with one or more extras. Stag reinforcement according to claim 1, characterized in that the side straps (4) and / or the middle web piece (3) are fold-like. 96711 7. Stag reinforcement according to any of claims 2-4, characterized in that the stag reinforcement is formed by interconnecting two stag reinforcements, so that a stag reinforcement thus formed works in the same manner in relation to the cutting stress which is directed to the stag reinforcement. containing the construction. 8. Stag reinforcement according to any one of claims 1-7, characterized in that the intermediate piece (3) is arranged jointly for several projecting parts (4). 9. Stag reinforcement according to any of claims 1 to 8, characterized in that the spacer or pieces (3) are arranged at least substantially oblique with respect to the cutting stress, which is directed to the stag reinforcement containing the construction. Stag reinforcement according to any one of claims 1 to 9, characterized in that the free ends of the projection parts (4) are provided with a transverse projection. »•« •