EP0677363B2 - Process and device for making elements from gas concrete or similar material - Google Patents

Abstract

In a method for producing bodies of gas concrete or the like, in which firstly a pourable, curable slurry comprising the basic materials for the body is produced, then an expanding agent (foaming agent) is added and the mass obtained is poured into a moulding box (2), provision is made, in order to reduce the size and number of the air inclusions remaining in the finished gas-concrete body, substantially before the beginning of the rising process, for a screen arrangement (8) having a mesh size which entrains damaging inclusions to be drawn through the mass and out of the latter. <IMAGE>

Description

The invention relates to a method and a device which in the preambles of claims 1 and 8 mentioned type for the production of bodies from gas concrete or similar.

• Reine Gasbetonelemente bzw. -steine, die durch Zerschneiden eines zuvor in einem Formkasten gegossenen Gasbetonblocks erzeugt werden und ausschließlich aus der erhärteten Gasbetonmasse bestehen; dazu gießt man eine mit einem Treibmittel versehene Gasbetonschlämme in den Formkasten, läßt diese steigen und wenigstens so weit erhärten, daß sie geschnitten werden kann. Nach dem Entformen wird der Block in einem oder mehreren Arbeitsgängen in die einzelnen Bauelemente zerschnitten.
• Mit Bewehrungs- oder Armierungselementen versehene Gasbeton-Fertigelemente, die bereits in der Form gegossen werden, in der sie später verwendet werden; dazu wird die mit einem Treibmittel versehene Gasbetonschlämme in einen entsprechend ausgebildeten Formkasten gegossen; bevor der eigentliche Treib- oder Steigvorgang einsetzt, werden die Armierungselemente so in den Formkasten eingesetzt, daß sie zunächst zum Teil in die Schlämme eintauchen und dann während des Steigvorganges von dieser nach und nach ganz oder teilweise umschlossen werden.

Known (see for example DE-B-2923626) manufacturing processes or manufacturing devices are used to produce two fundamentally different types of components:

• Pure gas concrete elements or stones, which are produced by cutting a gas concrete block previously cast in a molding box and consist exclusively of the hardened gas concrete mass; To do this, pour a gas concrete slurry provided with a blowing agent into the molding box, let it rise and harden at least to the extent that it can be cut. After removal from the mold, the block is cut into the individual components in one or more work steps.
• Prefabricated aerated concrete elements with reinforcement or reinforcement elements that are already cast in the form in which they will be used later; for this purpose, the gas concrete slurry provided with a blowing agent is poured into a suitably designed molding box; Before the actual driving or climbing process begins, the reinforcement elements are inserted into the molding box in such a way that they are partly immersed in the sludge and then gradually or completely enclosed by the sludge during the climbing process.

Results in both types of gas concrete elements the problem in the prior art that the Sludges from a relatively high height (1.5 to 2 m) and with relatively high flow rate in the mold box is poured in, which inevitably entrains air and there will be air pockets. These air pockets can rise completely inside and gradually solidifying gas concrete mass or also at their interfaces with the walls of the molding box lying down.

Becomes a non-reinforced block in the further production process cut into individual gas concrete elements, so the air pockets mentioned on the new emerging surfaces become visible and there Pits with e.g. several centimeters deep. in the The gas concrete elements can only be used later to a limited extent so that at their Air bubbles in the built-in surface Condition are not visible. It is possible to single, especially many bubbles Discard gas concrete elements as a committee; the is, however, only limited for cost reasons Dimensions possible. Non-reinforced gas concrete elements Although plastered in general, it is often found here using a thin plaster that is unable to Air pockets reaching the surface without further ado cover.

For reinforced gas concrete elements, which after the Demoulding not be cut, are only those air pockets reaching to the surface are visible, but disturb there even more than such armored components generally no longer plastered but can only be painted with a concrete paint, so that the air pockets remain clearly visible. On Weed out large, reinforced gas concrete elements as Committee is generally too expensive.

Because the surface of gas concrete components often very much because of the air pockets mentioned is unsightly, there are often complaints from the Customers. It is therefore often the case that visible in the walls of the completed building Air pockets through time-consuming and costly Filler work to be compensated before then the paint or plaster is applied can be.

Add to that the strength of gas concrete elements also due to invisible air pockets is adversely affected. The size of such air pockets can be up to several centimeters.

The invention is therefore based on the object Method and device for the production of To further develop gas concrete elements so that size and Number of remaining in the finished elements Air pockets are reduced as much as possible.

To solve this problem is one method the type mentioned in the preamble of claim 1 provided that essentially before the start of the climbing process a Screen assembly with a damaging inclusion Mesh size through and pulled out of the mass and is conducted so that it essentially the entire mass located in the molding box, so that all Gas and foreign body inclusions taken away from the sieve arrangement and be removed from the crowd.

The sieve arrangement preferably begins to be pulled through and pulled out already while pouring the mass into the molding box. It has been shown that enclosed gas bubbles, the air entrained in the pouring or also from hydrogen formed by the onset of the driving process or formed from an air-hydrogen mixture, largely taken away and pulled out of the crowd. It could be achieved in this way that the according to the invention Process manufactured armored and non-armored Bodies have a much better homogeneity than that Body made by conventional methods.

A particular advantage of the method according to the invention is can be seen in the following: The aerated concrete slurry often contains Lime or cement chunks that come from deposits, which can form in the mixing container. The mixing tank is cleaned regularly; however, it can Compliance with a reasonable effort is not prevented be that residues remain in the mixing container, which as more or less large chunks get into the mix. This Chunks, the hardness of which is generally much greater than that of the block that may have to be cut, lead to bad cuts as they use the cutting wires deflect or even damage. However, they become largely as a result of the method according to the invention removed from the gas concrete mass, so that by the miscarriages mentioned caused considerable waste can be reduced.

In a preferred embodiment of the invention, that the sieve assembly before pouring the mass onto the Lay the bottom of the molding box and after pouring is lifted out of the crowd at the top. This will make the natural Tendency of gas inclusions, in the mass upwards to rise, supports. It is provided that the sieve arrangement pulled through the crowd at a speed the highest is equal to the flow rate the mass through the sieve surface. That way the mass is not "stirred", so there is a risk of air pockets again to cause is excluded.

In addition, it may be advantageous to use the sieve arrangement Pull through the mass across the pulling motion to move and / or her vibrations of small amplitude to be stamped in the direction of pull. This will make the screening process generally improved again.

In order to manufacture armored bodies, according to the invention after pulling and lifting the sieve assembly from the mass and essentially before the start of the climbing process Reinforcing elements introduced into the molding box. The reinforcing elements are therefore essentially in one inclusion-free mass introduced at then climbing the reinforcing elements in one encloses this fully wetting manner.

For the implementation of the method according to the invention a device is provided which comprises a molding box, in which the manufactured in a mixing device, with a Propellant-containing sludge via a pouring device is poured. According to the invention, this device a sieve arrangement which can be introduced into the molding box and which a roughly corresponding to the shape and size of the mold box base Has screen area, as well as means allocated to this screen arrangement pull through the mass and lift out of it.

In a preferred embodiment of the invention it is provided that the sieve assembly on the bottom of the molding box before casting hung up or positioned near the floor and then lifted up and out of the mass becomes. This construction ensures that the entire mass in the molding box is the sieve arrangement must happen so that air and foreign body inclusions can be fully grasped. It is also one of them Arrangement can also be implemented in a structurally simple manner, as explained in more detail using an exemplary embodiment becomes.

The screen arrangement is according to a further embodiment the invention as a strainer basket with a forming the basket bottom Sieve surface and a basket rim surrounding the basket bottom educated. This configuration ensures that not part of the mass over the side margin of the sieve bottom flows and thus unscreened between the Sieve bottom and the wall of the molding box.

The sieve arrangement is preferably made of a wire mesh or braid formed. Such wire mesh or -braids are available as commercially available components, so that the screen arrangement can be manufactured inexpensively.

The mesh size of the sieve arrangement can be based on the size the inclusions to be covered by it, be coordinated. A mesh size has proven to be favorable proven between 2 and 10 mm. Sieve arrangements with a mesh size at the lower limit of the specified Ranges are generally sufficient to include smaller ones Detect gas inclusions up to an order of magnitude the unplastered Gas concrete elements are perceived as annoying. A mesh size at the upper limit of the specified The area is suitable for gas concrete elements be plastered later; has the larger mesh size the advantage that the screening process runs faster.

The means to pull and lift the Sieve arrangement can be used, in particular, for a Sieve arrangement drawn through the mass above with a simple hanging harness that can be moved up and down be educated. With the vertical lowering or The sieve assembly is lifted by the side walls of the molding box itself. On this way you achieve a particularly simple and inexpensive construction.

The hanging gear can be designed so that there are also facilities for optionally holding in the reinforcement elements to be used Has. After lifting out the sieve arrangement this can and can be suspended from the molding box Reinforcing elements are attached to the are then introduced into the sieved mass.

In a further embodiment, means for going there and back Moving the screen assembly substantially across provided for the pulling movement of this sieve arrangement. By moving the screen arrangement back and forth during the pull-through movement the Sieving process can generally be improved again.

An embodiment of the invention is in the Drawing shown and described in more detail below.

The figure shows a cuboid, open at the top Molding box 2 for the manufacture of a gas concrete block. The molding box 2 is double-walled in a known manner executed so that between the side walls of a Outer box 4 and an inner box 6 an intermediate space remains in which a coolant, for example Water that can circulate.

To produce gas concrete are not in one shown, arranged above the molding box Mixing device the necessary components a pourable aerated concrete slurry. This mixing process can already be included come from air bubbles. By means of one Pouring device is then the aerated concrete slurry, the a blowing agent, for example aluminum powder, shortly before has been added to the inner box 6 of Mold box 2 filled.

Since the pouring device from constructive and operational reasons often proportionate is located high above the molding box 2, it is unavoidable that air is entrained even when filling and mixed into the poured mass. In addition, the mass often contains chunks of lime or cement, despite regular cleaning of the Store mixing and pouring devices in these and in a subsequent batch into the gas concrete mass reach.

For gas and foreign body inclusions from the To remove gas concrete mass is a sieve arrangement 8 provided that before the casting process by means of a up and down movable harness 10 in the Inner box 6 is used. The screen assembly 8 is formed as a strainer basket and includes a basket bottom 12, which forms the actual screen surface, and one the basket rim surrounding the basket bottom 14. The dimensions the strainer basket are chosen so that this with a low tolerance that facilitates handling fits into the inner box 6, as in the drawing is shown in dashed lines. The basket rim 14 has a height at least equal to the height in the Inner box 6 is freshly filled gas concrete mass, so that they do not go over the top of the basket can.

To manufacture a gas concrete block, the Sieve arrangement 8 by means of the hanging gear 10 in the Inner box 6 used. Then the pourable, aerated concrete mass provided with a blowing agent filled into the inner box 6. If possible before the gas concrete mass starts to climb is the sieve arrangement upwards from the gas concrete mass lifted out, the lifting speed at most equal to the flow rate of the Mass is through the sieve surface, so not in the sieve basket existing mass of the already flowed through Mass is lifted and new air pockets in the Mass are introduced.

To prevent yourself from touching the screen assembly 8 lumps of mass can deposit additional funds 16 be provided, the sieve assembly 8 both a Back and forth movement in the sieve plane as well as vertically to give.

If the sieve assembly 8 taking the in the gas and foreign body inclusions in the gas concrete mass is completely different from the crowd, for example, it is swiveled to the side and cleaned, with the possibility of the cleaning process by shaking by means of the device 16 support.

If a reinforced gas concrete element in the molding box 2 is to be manufactured, there is the possibility the sieve arrangement 8 from the hanging gear 10 depend and instead not shown Reinforcing elements attach that essentially before the start of the climbing process into the cast Gas concrete mass are used.

Claims (18)

1. A process for the production of bodies from aerated concrete or the like including the following process steps:

   producing a pourable hardenable slurry from the basic materials for the body,

   adding a propellant, and

   pouring the resulting mass into a moulding box in which it can rise and harden,

      characterised in that substantially before the beginning of the rising phase a sieve arrangement (8) of a mesh size which entrains harmful inclusions is drawn through and out of the mass and is in that operation so guided that it engages substantially the whole of the mass in the moulding box (2) so that all gas and foreign body inclusions are entrained by the sieve arrangement (8) and removed from the mass.
2. A process according to claim 1 characterised in that the operation of drawing the sieve arrangement (8) through and out of the mass is already begun during the operation of pouring the mass into the moulding box (2).
3. A process according to claim 1 or claim 2 characterised in that the sieve arrangement (8) is put on to the bottom of the moulding box (6) before the mass is poured in, and is lifted upwardly out of the mass.
4. A process according to one of claims 1 to 3 characterised in that the sieve arrangement (8) is drawn through the mass at a speed which is at most equal to the speed of flow of the mass through the sieve surface.
5. A process according to one of claims 1 to 4 characterised in that as the sieve arrangement (8) is drawn through the mass it is additionally reciprocated transversely with respect to the movement of drawing it through the mass.
6. A process according to one of claims 1 to 5 characterised in that as the sieve arrangement (8) is drawn through the mass it is additionally vibrated in the direction in which it is drawn through the mass.
7. A process according to one of claims 1 to 6 for the production of reinforced bodies characterised in that after the sieve arrangement (8) has been drawn through and lifted out of the mass and substantially before the beginning of the rising phase reinforcing elements are introduced into the moulding box.
8. Apparatus for carrying out the process according to one of claims 1 to 7 including a moulding box for receiving a pourable slurry characterised by a sieve arrangement (8) which can be introduced into the moulding box (2) and which has a sieve surface which approximately corresponds to the shape and size of the bottom of the moulding box, and means for drawing the sieve arrangement (8) through the mass and for lifting it out of same.
9. Apparatus according to claim 8 characterised in that the sieve arrangement (8) is formed from a wire mesh or net.
10. Apparatus according to one of claims 8 and 9 characterised in that the sieve arrangement (8) has a mesh size of between 2 and 10 mm.
11. Apparatus according to one of claims 8 to 10 characterised in that the means for drawing the sieve arrangement (8) through the mass and lifting it out of same are formed by a suspension gear (10) which can be moved up and down.
12. Apparatus according to claim 11 characterised in that the suspension gear (10) has devices for selectively holding reinforcing elements to be fitted into the moulding box (2).
13. Apparatus according to one of claims 8 to 12 characterised in that there are provided means (16) for reciprocating the sieve arrangement (8) in substantially transverse relationship to the movement with which said sieve arrangement is drawn through the mass.
14. Apparatus according to one of claims 8 to 13 characterised in that there are provided means (16) serving to cause the sieve arrangement (8) to vibrate in the direction in which it is drawn through the mass.
15. Apparatus according to one of claims 8 to 14 characterised in that the sieve arrangement (8) includes a sieve basket which is provided with a sieve surface forming the basket bottom (12) and a basket edge (14) surrounding the basket bottom.
16. Apparatus according to one of claims 8 to 14 characterised in that the sieve arrangement includes a plurality of sieve baskets, each of which has a sieve surface forming the basket bottom and a basket edge surrounding the basket bottom, and that the sieve baskets are so arranged and suspended in mutually juxtaposed relationship that in the inserted condition their basket bottoms approximately cover the bottom of the moulding box.
17. Apparatus according to claim 16 characterised in that the baskets are suspended in a condition of being decoupled from each other and can be displaced independently of each other with reciprocating movements which are substantially transverse and/or perpendicular with respect to the direction in which the sieve arrangement is drawn through the mass.
18. Apparatus according to one of claims 15 to 17 characterised in that the basket edges are also in the form of a sieve.

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