EP1026335A2 - Prefabricated concrete element - Google Patents

Abstract

The section consists of lower section with a right-angled cross-section (1, 14, 19, 21) and, at least, one projecting connecting section above the upper side of the lower section. The to-be-mounted concrete fixture (4), on the fabricated section, has a key-locked connection. The connecting section has a steel-concrete mount with a right-angled cross-section, with a section of it being in contact with the upper surface of a push-connected transferring structure. The longitudinal reinforcement of the steel-concrete mount may be pre-stressed. The lower section and the mount may be one-piece in relation to each other.

Description

The invention relates to a novel design of prefabricated steel, prestressed and fiber-reinforced concrete parts, which are supplemented with in-situ concrete, the prefabricated parts achieve significant advantages in the construction stages through the new type of training and a favorable interaction with the in-situ concrete in the final state to back up. With the help of the device according to the invention, almost all beam and plate-shaped prefabricated structures with in-situ concrete addition can be more economical than previously run.

The formation of prefabricated parts according to the invention can initially for ceiling panels applied, which are manufactured by prefabricated parts with in-situ concrete supplement become. Comparable components have been known for decades such as prefabricated ceilings, element ceilings, lattice girder ceilings or Filigree panels are used and are nowadays used in residential construction and constructively related area of commercial construction represents the control solution, since it the economic advantages of prefabricated construction with the structural advantages of the in-situ concrete. Thanks to the precast panels, time and Thus, labor-intensive formwork work almost completely and armor largely avoided. The in-situ concrete supplement to be applied continuously reliably ensures the required stiffening of the structures. The exposed concrete lower surface is another advantage over pure in-situ concrete solutions the slab (omission of the plaster) and the reduction in construction time.

The previously known partial prefabricated ceilings consist of a lower, approx. 4 to 8 cm thick precast reinforced concrete slab and a supplementary in-situ concrete layer to form a solid reinforced concrete slab. The interaction of the two Components are achieved by truss-like steel lattice girders, which with the lower plate reinforcement can be installed in the prefabricated part and in the later applied in-situ concrete is sufficient. In construction - until the in-situ concrete has hardened - The lattice girders also have the task of being the bending girders Panel dead weight and the traffic loads occurring during construction to guide the plate supports or to provisional intermediate supports.

A major disadvantage of this design is that usually despite precast construction, auxiliary support is still necessary because the lattice girders effective in the construction state only have a limited load capacity and Have flexural rigidity and the arrangement of larger numbers or stronger carriers would become too uneconomical. Another variant to the pure steel lattice girders, where the steel upper flange is the lattice girder additionally with pressure-resistant concrete is required for larger ones Spans also auxiliary supports. Another major limitation of these systems is that the effective in construction Steel lattice girders do not offer favorable conditions to take advantage of To be able to use prestressed concrete. The limitations shown have led to the fact that the use of the partial prefabricated ceilings has predominantly so far limited to smaller spans and usually additional ones Aid costs incurred.

Especially with larger spans, therefore, come increasingly Prefabricated solid panels for execution, which mostly save weight with cavities are provided. These systems do not require auxiliary support and are well suited for pretensioning, which is also used frequently. The major disadvantage of this system is the lack of continuous in-situ concrete supplementation; the finished parts have to be complex with each other and with the supports be non-positively connected for all occurring stresses. Even in the final state, these panels form single-field, uniaxial load-bearing systems and can the favorable carrying behavior continuously and / or biaxially not reach tense systems.

Based on this, it is therefore the task of solid concrete slabs Present invention, the precast elements so that they too with larger spans of the final solid slabs in the construction state without Get help, favorable conditions for preload offer and are designed so that they are a continuously effective in-situ concrete supplement receive.

This object is achieved in that the previously at Partially prefabricated ceilings exclusively used steel lattice girders through concrete beams which are usually replaced together with the lower prefabricated panel are produced and are characterized in that their lateral Landing surfaces are designed so that they with the in-situ concrete added later achieve a positive connection. These bars can easily be designed and dimensioned so that they are economically in the state of construction occurring loads with each practically occurring span without Aid can guide to the supports of the plates. This in Construction status of existing concrete beams are also very good for prestressing suitable. This can be particularly useful for larger spans economical solutions can be achieved because the Ceiling thicknesses and thus the weight of the construction is minimized and at the same time no problems due to excessive deflections can arise.

After the hardening of the additionally added in-situ concrete, the concrete beams should form a reliable bond with the in-situ concrete, so that the Remove the load in the final state as a solid plate with a uniform effect. This required bond is achieved by the lateral web surfaces of the Concrete beams are designed so that they work together of the bonded forces required from the precast and in-situ concrete.

The formation of the precast elements to complement with in-situ concrete to massive Platten thus combines the respective advantages of the previously known, competing Systems of lattice girder ceilings and precast hollow panels by they do not need support, very good for low cost Fitted bed prestressing are suitable and due to the in-situ concrete supplement continuous and / or biaxial bearing plate systems with cheaper Washer load capacity can be supplemented. It also gives that smooth ceiling underside and the optimal reduction in construction time.

The formation of the prefabricated parts with composite web side surfaces can can also be used to advantage in various beam-like prefabricated parts. In all applications, the construction will be more favorable compared to conventionally trained prefabricated parts achieved by a larger beam height and in many cases a much cheaper bending pressure zone is achieved with better support conditions. This can often the design height for the final state can be reduced, which immediately to economic and, if necessary, design, as well as indirectly over less Storey heights lead to further economic advantages.

The design of prefabricated parts according to the invention for various application examples is explained in more detail below with reference to the drawings.

Figur 1

einen Querschnitt durch ein Fertigteil zur Herstellung von Massivplatten,

Figur 2

eine Draufsicht auf ein Fertigteil zur Herstellung von Massivplatten,

Figur 3

einen Längsschnitt durch ein Fertigteil zur Herstellung von Massivplatten,

Figur 4

einen Längsschnitt durch eine Variante des Fertigteils gemäß Figur 3,

Figur 5

eine isometrische Darstellung des in den Figuren 1 bis 3 dargestellten Fertigteils,

Figur 6

einen Teilquerschnitt durch ein Fertigteil,

Figur 6 a

ein Schalungsblech für ein Fertigteil,

Figur 7

eine Draufsicht auf ein Fertigteil mit Querträger,

Figur 8

einen Querschnitt durch ein Fertigteil zur Herstellung von Massivplatten mit abgestuften Deckenstärken,

Figur 9

einen Querschnitt durch ein Fertigteil in Form von sogenannten π-Platten und

Figur 10

eine perspektivische Darstellung eines rechteckförmigen Fertigteilbalkens mit Ergänzung.

Here show:

Figure 1

a cross section through a finished part for the production of solid sheets,

Figure 2

a plan view of a finished part for the production of solid sheets,

Figure 3

a longitudinal section through a finished part for the production of solid panels,

Figure 4

3 shows a longitudinal section through a variant of the prefabricated part according to FIG. 3,

Figure 5

2 shows an isometric representation of the finished part shown in FIGS. 1 to 3,

Figure 6

a partial cross section through a finished part,

Figure 6 a

a formwork sheet for a prefabricated part,

Figure 7

a plan view of a finished part with cross member,

Figure 8

a cross section through a prefabricated part for the production of solid panels with graduated ceiling thicknesses,

Figure 9

a cross section through a finished part in the form of so-called π plates and

Figure 10

a perspective view of a rectangular precast beam with addition.

FIG. 1 shows the cross section through a multi-wall composite panel, which consists of the Web 1 and the lower plate 2 is made. Training is an essential feature the lateral web surfaces 3 such that the composite web panel with the later in-situ concrete supplement 4, the upper edge 5 shown in dashed lines is a frictional bond.

FIG. 2 shows the top view of a multi-wall composite panel 6. For larger ones Ceiling fields are to be arranged side by side several composite panels. Accordingly, in Figures 1 and 2 there is also a laterally adjoining one Element 7 shown.

The special design of the lateral web surfaces 3 is shown in FIG. 2 The top view shown can be seen particularly well in the for better readability the top 8 of the web is highlighted by dashed hatching are. The training according to the invention for the non-positive connection is exemplified by a trapezoidal profile of the web surfaces. Of course, this frictional connection can also be achieved by sawtooth-like, wave-like or otherwise suitable formwork forms such as knob formwork can be achieved. Alternatively, other solutions such as B. Formation of the web side surfaces with perforated and profiled sheets such as e.g. B. Expanded rib metal, faltering, washed concrete structure, connecting shear reinforcement, Dowels or other measures. Of course, are out constructive reasons also the other contact areas for later in-situ concrete addition to be carried out roughly in order to achieve the best possible bond - on which it is not essential - to achieve.

FIG. 3 shows a longitudinal section through the composite web panel, wherein the webs 1 protruding from the lower plate 2 in this illustration have the same height over the entire length of the panel. That height will preferably chosen so that the upper plate reinforcement directly on the top of the web 8 can be placed and then the required concrete cover this reinforcement is guaranteed by the in-situ concrete supplement 5. If, in individual cases, no upper reinforcement is required in the web areas , the top edge of the webs can be level with the top edge of the in-situ concrete supplement be chosen.

In most applications, the solid panels are in the middle Top area no reinforcement required. Occurs in this area at the same time the greatest stress of the multi-wall sheets in the construction state on. It is therefore advisable to make the webs as high as possible in this area, thereby the load-bearing capacity in the construction state in an economical manner to increase. In Figure 4 is a longitudinal section through a corresponding Variant of multi-wall composite panels shown, in which the web top edges 8 in middle field area flush with the later concrete upper edge 5 of the final Solid sheet lying. Deviating from the previously known, comparable As a result, systems occur with multi-wall sheets - unless they do can be produced with the help of remaining sheets - no corrosion problems on. In the present case, the variable course of the upper edge of the web 8 exemplified by cove-shaped steps with negligibly small To produce additional effort compared to constant web heights. Alternative would be a gable roof-shaped course of the top edges of the web is also conceivable. Through such Shapes are achieved that the load-bearing beams of the multi-wall sheets the largest cross section in the area of the greatest bending stress have and at the same time in the less stressed areas There is the possibility of space for the plate reinforcement to be arranged in the upper layer to hold.

For a better overview, FIG. 5 shows this in FIGS. 1 to 3 Cross section, top view and longitudinal section of the finished part shown in an isometric representation. With this representation u. a. It can be seen that the multi-wall sheets in the construction state inverted rib ceilings represent and accordingly simplified, economic design rules can be applied. Furthermore, by the representation also understandable that after the addition of the in-situ concrete resulting solid sheets also bending stresses transverse to the web direction received - be it only as a result of the transverse contraction in uniaxial clamps Slabs or from direct biaxial load-bearing capacity. With conventional Lattice girder ceilings will only make the associated cross reinforcement friendly to the construction site installed in the lower plate if the finished solid plate is uniaxial wearing. In the joint area, the required reinforcement before the in-situ concrete is added placed on the lower plates. With two-axis load capacity on the other hand, the entire transverse reinforcement on site is laborious the lattice girders threaded. This comparatively large and very unpopular Effort is avoided in practice in that biaxially tensioned Slabs downgraded to uniaxial loadbearing by design become, which in turn always leads to uneconomical solutions.

In the case of the formation of the partial prefabricated ceilings presented here, in principle proceed in the same way. For threading the cross reinforcement profiled empty tubes could preferably be installed in the webs, whose cross-section would be chosen so that this transverse reinforcement too in the web area after the in-situ concrete supplement for the required corrosion protection is reliably encased in concrete. With the resulting Empty pipe cross sections would also ensure that the installation of the Cross reinforcement would not be more complex than conventional ones Lattice girder ceilings.

A very significant advantage can be achieved if reinforcements, which are installed in the lower plate so that they the joints running parallel to the webs between adjacent ones Bridge the composite panels with a force fit. Corresponding new types Solutions that are also used advantageously in the previously known systems can be presented elsewhere.

Because prefabricated ceilings are usually produced in fully automatic systems the additional required compared to conventional systems Web formwork does not represent any significant additional effort. Nevertheless in one case or another it may be beneficial to add this To avoid formwork. This can be achieved for example by the in the construction shown in Figure 6. Here the conventional formwork is replaced through perforated and profiled sheets 9, the shape of which for clarification is once again shown individually in FIG. 6 a. Through such sheets can also create a very good bond between the bars and the in-situ concrete supplement be ensured. The upper bend 10 a can in sections also stay erect (10 b) and thus also allows in this variant, the manufacture of webs with variable height is easy according to FIG. 4.

The individual formwork sheets of this design variant can be simple and advantageously be joined together to form a unit via plug-in bracket 11. These plug-in brackets can also be used as suspension reinforcement in the construction state for the load on the lower plates 2. If the Formwork sheets are equipped with a bead 12, this not only serves the required sheet metal bracing, but also offers the possibility of Formwork sheets only afterwards - after concreting the lower slab 2 - fit exactly and thus a particularly simple workflow to enable. For this purpose, the bead 12 is to be formed exactly as high that the formwork sheets reach their required position exactly when the bead sits on the transverse reinforcement 13. The formwork sheets can according to shape and cross section are also designed so that they are both in Construction state as well as in the final state as compression, tension and shear reinforcement Act.

Another possibility to minimize the effort for the web formwork, if necessary, consists of prefabricating the webs in their own formwork and then to lay in the fresh concrete of the slabs 2.

The essential advantage of the construction of partial prefabricated ceilings according to the invention , namely the fact that there is no need for any auxiliary supports, can even be extended to the frequently occurring case that the panel supports are interrupted by openings by appropriate design of the multi-wall composite panels. In these cases, the auxiliary support that would otherwise be required can be avoided by the formation of cross members 14 according to the plan view in FIG. 7.

The cross section shown in FIG. 8 shows a very detailed section advantageous variant of today's flat ceilings. The Element 15 represents the ceiling area between the supports, the is also referred to as a belt strip while the element placed on it 16 is arranged in the much less stressed field area. Because of the favorable load-bearing capacity of the finished parts - especially if they are biased - it is sufficient if the belt strip elements 15 together with the in-situ concrete supplement 4 the strength of a comparable flat ceiling exhibit. The field elements 16, however, can be significantly lower be formed. This not only allows the clearly recognizable, extremely easy installation option, but also leads to clearly lower material consumption, which not only results in direct cost advantages, but more about the lower load on the entire supporting structure Cost advantages means.

The proposed training of part-finished ceiling provides for all applications is another, very simple way, in the ceiling structure weight (and concrete) to save: It need only prior to the introduction of floor systems - the easiest already in the precast plant - on the lower plates 2 according to the representations 8 light packing 17 are installed.

Since none in the application variant shown in FIG Formwork and only to a very limited extent auxiliary supports in the column areas are necessary as well as no lower reinforcement on the construction site can be installed completely compared to conventional construction methods considerable time advantages are achieved, which ultimately also additional mean significant cost advantages.

The training of prefabricated steel, prestressed and fiber-reinforced concrete by in-situ concrete can be supplemented, in addition to the solid slabs presented here almost all previously known beam-shaped prefabricated parts are extremely advantageous be applied. The designs known to date are all thereby characterized that for the bond between the prefabricated parts and the in-situ concrete supplement Reinforcement protrudes from the prefabricated parts into the in-situ concrete. Becomes however, the composite reinforcement is replaced by prefabricated additions, the task of the association with training according to the invention of the in-situ concrete supplement, the precast elements can be considerably achieve better load-bearing capacity. This allows i. d. R. the construction height for the prefabricated parts including in-situ concrete supplement compared to conventional ones Systems are reduced, resulting in further economic and design Advantages leads.

Examples of this advantageous embodiment are 9 π-plate elements in the figure 18 shown. The elements are each different from the conventional ones Shaping supplemented at the top by composite panel elements 19. The illustration clearly shows that this does not only mean that in the state of construction effective construction height can be increased significantly, but that at the same time, the finished parts to extremely powerful cross-section beams be expanded, which is particularly true for pre-stressed prefabricated parts is particularly advantageous and also with single-ply slab beams, as in Bridge construction can be used, can be applied extremely advantageously. Another great advantage of the composite panel elements 19 is that in the support area to high-performance support brackets with a low overall height can be trained. Become the associated support bracket Designed according to Figure 10, both elements can together to a considerable Reduction of the construction height and thereby to corresponding economic benefits.

In the perspective view of the end area of a precast member 20 with a rectangular cross section (FIG. 10) and head extension 21 with a bridge assembly it is also clear that the construction heights always cheaper can be achieved. These can be used in numerous precast designs Cases, especially in the support areas, bring great advantages, if - as shown - they have to be designed like a console (22). In these cases, it is particularly favorable if, due to the shown training compared to conventional solutions in the state of construction larger heights are available.

Claims (10)

Slab or beam-shaped precast concrete element that can be supplemented with in-situ concrete (4), in particular precast steel, prestressed or fiber-reinforced concrete from a lower part with a substantially rectangular cross section and from at least one composite part protruding over the top of the lower part, that with the in-situ concrete to be applied to the precast reinforced concrete element (4) forms a non-positive connection, the connection part being a reinforced concrete web (1, 14, 19, 21), in which at least part of the in-situ concrete (4) is in contact coming surface has a structure transferring composite forces, and wherein the web (1, 14, 19, 21) has an approximately rectangular cross section and the structure transmitting the composite forces to the Web side surfaces (3) is provided. Precast concrete part according to claim 1, characterized in that the structure transmitting the composite forces is a structure interlocking with in-situ concrete (4). Precast concrete part according to claim 1 or 2, characterized in that the structure transmitting the composite forces consists of composite parts which protrude above the web surface and protrude into the in-situ concrete (4). Precast concrete part according to one of the preceding claims, characterized in that the longitudinal reinforcement of the reinforced concrete web (1, 19, 21) is prestressed. Precast concrete part according to one of the preceding claims, characterized in that the lower part and the web (1, 14, 19, 21) are integral with one another. Precast concrete part according to one of the preceding claims, characterized in that the web height increases along the web (1, 19, 21 towards the center. Precast concrete part according to one of the preceding claims, characterized in that it has a support bracket (22) on the edge, over which the web (21) extends. Precast concrete part according to one of the preceding claims, characterized in that the lower part is designed as a plate (2) on which a plurality of webs which run essentially parallel to one another are arranged. Precast concrete part according to claim 8, characterized in that the plate (2) has a reinforced lower flange in the area of at least one of the webs (1) running parallel to one another. Precast concrete part according to one of the preceding claims, characterized in that fillers (17) are introduced between the webs (1), the height of which is less than the web height.

Images