FI89092C - Process for making a reinforced concrete structure - Google Patents

Description

1 89092

Method for making a reinforced concrete structure -Förfarande för framställning av en armerad betongkonstruk-tion.

The present invention relates to a method according to claim 1 for producing a reinforced concrete structure for various structures.

Our previous patent application F1 894586 discloses a method for manufacturing a composite structure as a combination of a form plate, usually a steel profile plate and concrete, by injecting concrete into the form plate. The same patent application discloses the adhesion of a composite structure and the joining of different plates by forming plate folds. A small mesh cutting net made by stretching a steel sheet is known from U.S. Patent 1,864,598 and GB Patent 1409482. A generally diagonal and larger mesh grid made by cutting from a thicker metal sheet is known e.g. U.S. Patent 3,570,086. Our second patent application, FI 902487, discloses a method for making concrete subfloors for buildings.

The disadvantage of the known methods of manufacturing structures is e.g. the fact that large and heavy elements have to be brought to the construction site, which require efficient lifting equipment. However, the element structures usually do not reach the spans of the desired length. Alternatively, the structure is often made on site by casting. This in turn requires large formwork and scaffolding structures. On-site casting structures have to use temporary supports to support the fresh concrete mass. Doing and dismantling these will significantly slow down the progress of the work. Spray concreting through reinforcement layers is cumbersome by known methods and, in particular, the filling of steel backgrounds is often deficient. Implementing shotcreting in long span structures is cumbersome and usually requires separate supports.

The object of the present invention is to reduce the above-mentioned disadvantages and to provide a method by which shotcreting through successful reinforcement layers and in particular the filling of steel backgrounds is improved. This is achieved by the method according to the invention, in which shotcrete is sprayed from two or more nozzles from different directions into the same place.

A large number of different embodiments can be found for the invention. The following figures are intended to be illustrative only and to illustrate the operation of the invention. The positions of the structures can be selected arbitrarily. For the sake of clarity, the explanations of the figures speak e.g. from below and above, although it may also be a question of different lateral directions.

Figure 1 shows a perspective view of a part of a reinforcement grid according to the invention before adding concrete.

Fig. 2 shows a part of the reinforcement cross according to Fig. 1 after fixing the lower stiffeners of the lower surface 1.

Fig. 3 shows the reinforcement grid according to Fig. 1 or Fig. 2 after the addition of the heton layer at the end 11 of the background.

Figure 4 shows the spraying of concrete through reinforcement layers against the background with jets from different directions.

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Figure 5 shows an illustrative view of a non-mesh shape 1 in which diagonal strips cut from a sheet metal form buckle-like supports.

Fig. 6 shows an illustrative view of the section net structure according to Fig. 5 after fixing the transverse stiffeners of the lower surface.

Fig. 7 shows an illustrative view of the sectional mesh structure according to Fig. 6 after fixing the longitudinal stiffeners of the lower surface.

Fig. 8 shows an illustrative view of the structure according to Fig. 6 or Fig. 7 after the addition of concrete at the bottom.

Fig. 9 shows an illustrative view of the sectional mesh structure according to Fig. 5 after fixing the longitudinal stiffeners of the upper surface.

Fig. 10 shows a section in which the section net structure corresponding to Fig. 5 is bent into an arc and stiffened before concreting.

Figure 11 shows an illustrative view of a sectional mesh attached to a substrate, partially cut and bent vertically at the start of concreting on the background.

4,89092 The main object of the present invention is to provide a self-supporting composite structure as a combination of concrete and steel as efficiently as possible and with little human effort, especially suitable for long spans. The method according to the invention can be used to make structures with high bending stiffness. In this way, subsidies during construction can be avoided even at short intervals. It is also an object of the invention to reduce the transport and handling of heavy parts on site, when the final heavy structure is usually formed only at or near a permanent location.

Figure 1 shows a part of an elongate reinforcement lattice made of a so-called cutting net made of steel sheet by cutting and stretching. The strands 86 of the section net form a lattice in which the strands 86 are located diagonally to the longitudinal direction of the structure. The strands 86 are generally located as extensions of each other, so they effectively transmit forces. The diagonal strands 86 effectively transmit, for example, the shear forces of the beam-like structure. All the strands 86 of the cutting net are firmly attached to each other at the nodes, whereby the whole net is strong. In the manufacture of a cutting net, the strands 86 often rotate slightly about their longitudinal axis, so that even a planar cutting net has a degree of bending stiffness. In Fig. 1, the bending stiffness of the elongate structure is improved by shaping the cutting net in the middle into a corrugated ridge. The cutting net can be corrugated into different shaped profile shapes to improve rigidity. From the point of view of strength, e.g. triangular and trapezoidal and rectangular shapes in cross section are advantageous. The structure corresponding to Figure 1 can also be made of conventional reinforcing bars, e.g. by welding them together and bending them.

Figure 1 shows only a part of a very long structure with which to overcome long spans. Sovellu-

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5 89092 objects can be, for example, bridges and subfloors of buildings and other structures of this type. As a vertical structure, e.g. various walls and pillars. The structure is light without the weight of concrete. By adding concrete to the structure, a composite structure is formed that can withstand even greater stresses. The structure of Figure 1 is light but rigid for many purposes.

In Fig. 2, the profiled mesh 86, 86a is stiffened at its lower part by additional reinforcements 50 in both the longitudinal and transverse directions. In a horizontal beam, the tensile stresses are concentrated in the lower part, so additional reinforcement is especially needed there. Additional reinforcement can also be attached to other parts of the mesh as needed. Additional reinforcements can be attached, for example, by welding to the mesh grid 86, 86a to improve the strength before concreting. The additional reinforcements 50 can also be placed in other directions as required, e.g. diagonally. The vertical portion 86a of the network profile is the same network as the horizontal portion 86. For clarity, a different identification number has been used in the figure. The reinforcement structures 86, 86a, 50 retain their shape well even before concreting. The reinforcing structure 86, 86a, 50 can be raised, for example, even in a long span without special temporary supports so that the structure carries itself.

In Fig. 3, a concrete layer 6 is added to the lower part of the reinforcement network according to Fig. 1 or 2. The upper part of the ridge of the reinforcing mesh is above the concrete layer 6. Concreting is done on the base 27. By means of the smooth-surfaced substrate 27, the lower surface of the concrete layer 6 is made smooth. By initially spray-concreting only a thin layer of concrete 6, the additional reinforcements can be effectively attached to the structure, but the weight of the structure remains small. Once the concrete layer 6 has hardened, the strength of the structure improves and it can withstand even higher loads. New concrete layers can be added on top of the concrete layer 6 as the strength increases. The base 27 may be some kind of plate which can later be removed or left in the structure as a permanent part, e.g. as thermal insulation. The reinforcement grid 86, 86a can be completely covered with concrete layers. The inner part of the corrugation 6 89092 can, if desired, be left in the cavity by placing a densely mesh substantially impermeable to concrete on the surface of the corrugation 86, 86a.

Figure 4 shows the performance of shotcrete concreting using two concrete nozzles 5 so that the concrete is sprayed at the same location from different directions simultaneously. Concrete jets 4 coming from different directions collide behind the reinforcements 50 and effectively fill the background of the reinforcements. The different concrete jets 4 complement each other so that the possible blind area of the second jet is replaced by another jet. Partially colliding concrete jets 4 create packing laterally and partly behind the reinforcement 50 towards the reinforcement 50. The filling of the reinforcement background is facilitated by bouncing from a possible background 27. In this way, spray concreting can be done even through thick layers of reinforcement. Instead of two concrete jets 4, several concrete jets from different directions can be used if several nozzles 5 in different directions are used. The different nozzles 5 can be connected to each other by means of supports 82. If the supports 82 are made movable relative to each other, e.g. by means of a joint 89, the angle of impact of the jets and the mutual distance can be changed to suit different situations. With the presented principle, the backgrounds of different types of reinforcement can be concreted efficiently. The different nozzles 5 can have a common feed, which is divided by branch pieces into the necessary partial flows. Alternatively, each nozzle may have a separate supply hose. The group of two or more nozzles may be a manually movable or robotic type device placed on a support arm. With the remote control, even a heavy nozzle group can be moved accurately and efficiently even at the end of a long arm.

The type of section net shown in Figure 5 is flexible in both the longitudinal and transverse directions. The diagonals 86 form racks supporting the top surfaces 58 in both directions. The lower supports 33 bind the diagonals 86 in the other direction to each other.

In Fig. 6, the section net according to Fig. 5 is stiffened by a lower surface transverse stiffener 57, which can be e.g. For example, a dense mesh net can be attached to the inner surface of the diagonal supports 86 so that the inner surface of the girder supports 58, 86 is left empty during subsequent concreting.

In Figure 7, the lower surface is stiffened by lower surface supports 57 in both the longitudinal and transverse directions.

In Fig. 8, the lower part of the reinforcement according to the figure is reinforced with a thin concrete layer 6. A new concrete layer 8 can be made on top of the concrete layer 6. Diagonals 86 passing through the different concrete layers 6, 8 bind the concrete layers together to prevent possible detachment. Diagonals 86 can be provided with various gripping members to ensure adhesion between concrete and steel. Concrete layers can be made by spraying a large number so that the previous layers have time to harden and strengthen before the next layers are made. This causes the strength and weight of the structure to increase in the same rhythm.

Figure 9 shows the reinforcement of the upper surface of the cutting net with supports 52 in the longitudinal direction. Correspondingly, the upper surface can also be reinforced in the transverse direction.

In Fig. 10, for example, the sectional mesh structure corresponding to Fig. 5 is bent curved in the transverse direction. Prior to attaching the lower surface stiffener 57 and the upper surface stiffener 52 to the reinforcement containing the diagonals 86, the arc is bent. For example, the stiffeners attached by welding make the arch rigid, so that it can be placed, for example, as the frame of a vault structure. By first spraying a thin lower concrete layer 6, the transverse stiffness is increased with a small increase in weight. The longitudinal stiffness can be improved by longitudinal reinforcements 50. The lowest concrete layer can be sprayed, for example, against a small-mesh cutting net 10 or a temporary background can be used to make a flat surface. Once the lowest concrete layer has strengthened, new concrete layers 8 can be sprayed as required. Often in vaulted structures, all reinforcements are covered with 8,89092 layers of concrete to prevent corrosion in the reinforcements. The hardening of the concrete can be accelerated by various accelerators so that the previous layers quickly begin to carry the next layers. The reinforcement layer can be penetrated by spraying from two or more nozzles from different directions to the same point. In a corresponding manner, the sectional mesh structure can also be bent in the longitudinal direction, if desired, in which case domed shapes are created.

Fig. 11 shows a planar diagonal cutting net 86 with a portion 86a cut and bent in a perpendicular direction for adhesion between different layers of concrete. The base 27 is fastened with hooks 13 to the reinforcing mesh 86. The base 27 can, for example, hang from the mesh 86 at a suitable distance to form the surface of the concrete layer. Spraying from different directions easily penetrates the reinforcement network 86.

Spraying of large or high objects can be performed with the help of efficient spraying robots. In them, the work station itself comes with long-arm spray nozzles that can be remotely controlled without the presence of people in the actual work station.

Claims (5)

9 89092 A method of manufacturing a reinforced concrete structure, wherein the reinforcing lattice (86, 86a, 50) is stiffened to substantially self-supporting and then shotcrete 11a (6, 8) is reinforced, characterized in that the shotcrete (4) is sprayed from two or more nozzles (5). ) from different directions to the same place. Method according to Claim 1, characterized in that the reinforcement grid (86, 86a, 50) is formed from diagonal reinforcements which are attached to one another substantially. Method according to Claim 1 or 2, characterized in that the reinforcement grid (86, 86a, 50) is formed essentially from a sheet metal (86, 10) made of sheet metal by cutting and stretching. Method according to one of Claims 1 to 3, characterized in that the reinforcement grid is formed in a corrugated cross-section. Method according to one of Claims 1 to 4, characterized in that reinforcing reinforcements (50, 57, 52) are attached to the diagonal reinforcement mesh (86, 86a). 10 89092