Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/14—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies
  • B05D7/16—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies using synthetic lacquers or varnishes
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
  • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
  • E04C5/01—Reinforcing elements of metal, e.g. with non-structural coatings
  • E04C5/015—Anti-corrosion coatings or treating compositions, e.g. containing waterglass or based on another metal
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
  • E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
  • E04G21/12—Mounting of reinforcing inserts; Prestressing

Definitions

• the invention relates to a method for the treatment of holding rods for holding steel reinforcements in the manufacture of gas concrete, in which the holding rods are first immersed in a liquid separating agent, the coating thus formed is then hardened, then the steel reinforcements are attached to the holding rods and put them together be coated with an anti-corrosion agent using the holding rods.
• the steel reinforcements reinforcement mats and reinforcement bodies
• a corrosion protection coating before introducing them into the viscous gas concrete mass.
• the anti-corrosion agent In order to apply the anti-corrosion agent to the steel reinforcements, they are usually immersed in a bath filled with the anti-corrosion agent. So-called holding rods are used to hold the steel reinforcements during this immersion process, several of which are each fixed to a traverse or a frame.
• the holding rods are also coated with the corrosion protection agent. After the corrosion protection agent has dried, the reinforcements can be introduced into the casting mold. For this purpose, the trusses are placed on the upper edge of the mold.
• the holding rods now hold the steel reinforcements attached to them at the correct mutual distance and at a distance from the mold base and the side walls of the mold.
• the gas concrete mass is then poured into the mold. It floats to the desired height under the effect of aluminum powder.
• the holding rods are unlocked by the steel reinforcements and pulled up out of the gas concrete block by lifting the crossbars.
• these holding rods Before they can be used again, it is usually necessary to clean these holding rods, on the one hand because they are also coated with the anti-corrosion agent and on the other hand because there may be gas concrete residues adhering to the anti-corrosion agent If the anti-corrosion coating and any gas concrete residues were not removed, then this would be the case the support rods are covered with another coating layer when immersed again in the anti-corrosion agent bath, as are the gas concrete particles adhering to the rod. In this way the coating on the holding rods would become thicker and thicker. This would have the consequence that the holding rods can no longer be inserted through holes in the crossbeams and can no longer be pulled out.
• the desire for an environmentally friendly corrosion protection system has triggered the development of a water-based paint, i.e. a water-thinnable lacquer.
• a water-based paint i.e. a water-thinnable lacquer.
• These water-based paints provide an irreversible film, i.e. once they have dried, the corrosion protection coating can no longer be removed with water or solvents.
• Holding rods, which were immersed in a bath with water-based paint along with the steel reinforcement attached to them, can no longer be made free of paint after the water-based paint has dried using solvents.
• an aqueous release agent is applied to the holding rods before the corrosion protection agent is applied.
• This consists of 1.4 to 2.5% by mass of cellulose glycolic acid, 44 to 52.6% by mass of an inert inorganic powder such as slate flour, talc, chalk, kaolin, quartz powder and 46 to 53.5% by mass of water.
• These ingredients are stirred into a homogeneous mixture.
• the holding rods are immersed in the release agent consisting of these components. After immersion, a release agent coating with a layer thickness of 250 to 350 ⁇ m remains on the holding rods. Then the holding rods with the steel reinforcements attached to them are provided with a coating, in particular a powder coating.
• the aim of the separating layer is to ensure that it adheres better to the powder coating composition than to the holding rods, so that when the holding rods are pulled out, the coating of the holding rods formed by powder coating remains together with the separating layer in the gas concrete.
• this release agent In addition to the fact that it is not known whether this release agent can fully perform its function even in the case of corrosion protection coatings consisting of a water-based paint, the known release agent has various disadvantages. This is because this is not a commercially available product, but must be manufactured separately from the above-mentioned components, for which weighing units, time and mixer are required. Drying the relatively thick coating layer requires a long time or special energy-consuming drying devices. The relatively thick coating of an average of 300 ⁇ m can also be stripped when the holding rods are pushed through the relatively narrow bores of the crossmember or the support frame and also when inserted into the spacers of the reinforcement cages. Where the release agent layer has been stripped off, there is direct contact between the anti-corrosion agent and the holding rod.
• the anti-corrosion agent will stick to these points when pulled out on the holding rod and at least a partial cleaning of the holding rods is required.
• the release agent also contains a high proportion of water. This leads to corrosion of the steel holding rods.
• the corroded (rusted) surface of the holding rods becomes rough, so that when the holding rods are pulled out of the gas concrete block, at least parts of the separating agent layer remain on the holding rods.
• gas concrete remains can get caught here. As a result, at least partial cleaning of the holding rods is necessary in order to remove these residues as well.
• the invention has for its object to provide a method for the treatment of holding rods for the holding of steel reinforcements in the manufacture of gas concrete of the type mentioned, which enables the use of commercially available, inexpensive products as a release agent, in which a complete detachment of a water-resistant corrosion protection layer is guaranteed , no residues of gas concrete adhere to the holding rods, which means that the holding rods do not have to be cleaned after each work step.
• the holding rods are immersed in a hot bath of molten paraffin which is solid at room temperature and has a softening temperature of about 50 to 70 ° C. when using a water-based paint.
• the paraffin used to carry out the method according to the invention is a commercially available and also relatively inexpensive product. If suitable process conditions are adhered to, it can also be applied in a very thin layer thickness as a release agent coating to the holding rods by immersion, a layer thickness of approximately 20 to 50 ⁇ being completely sufficient. Each holding bar consumes only about 1 g. In addition to the low production costs of the release agent, the extremely low consumption also has an advantageous effect. Furthermore, the small layer thickness has the advantage that the release agent layer has the diameter of the holding rod practically not enlarged. As a result, the risk that the release agent layer is stripped when the holding rods are inserted into the bores of the cross members or support frame and into the spacers of the reinforcement cages is extremely low.
• the thin paraffin layer also adheres very well to the holding rods and even where it has been stripped off, there is still a residual film which prevents the corrosion protection coating from sticking to the holding rod when it is pulled out of the gas concrete block. It has been found that the anti-corrosion coating is removed from the holding rod without any residues and without problems when the holding rods are pulled out of the gas concrete block and remains as an empty shell in the gas concrete block.
• the excellent separating effect of the paraffin is due to the fact that the green gas concrete block heats up strongly during the ripening process.
• the temperature of the gas concrete mass rises to approx. 80 to 90 ° depending on the binder content. This temperature causes the paraffin to melt.
• the melting paraffin also prevents gas concrete from sticking to the upper areas of the holding rod, where there is no longer any corrosion protection coating.
• the support rods can therefore be pulled out of the gas concrete block completely bare and free of any residues, be they corrosion protection agents or gas concrete residues. Cleaning after every work process is not necessary.
• a thin paraffin film remains on the holding rod even after it has been pulled out protects the bearing against corrosion before applying a new paraffin coating.
• the holding rods do not need to be dried after the paraffin layer has been applied, rather it is sufficient if they are cooled to room temperature.
• the paraffin layer solidifies. The solidified paraffin layer behaves neutrally and in no way influences the water-based paint when the steel reinforcements and the holding rods are immersed in the anti-corrosion agent bath.
• the holding rods are expediently left in the paraffin bath until they have approximately reached their temperature. It was found that a very thin release agent layer of approximately 0.8 to 1 g can be achieved with this procedure.
• This thin release agent layer has the advantage of a low consumption of paraffin and, in addition, the thinner this layer, the lower the risk of unwanted stripping of the paraffin layer.
• optimal results were achieved with a diving time of about 5 minutes. The amounts consumed per stick were around 0.8 to 1 g.
• the rods can be warmed up before being placed in the paraffin bath.
• additional facilities would be required for this.
• the method can expediently also be carried out in such a way that the holding rods are heated by the gas concrete block that heats up during the ripening, that the holding rods are pulled out of the gas concrete block at the end of the ripening and still in warm condition can be immersed in the paraffin bath.
• This immersion of the support rods immediately after they are pulled out of the gas concrete block is possible because the support rods can be pulled bare and residue-free from the gas concrete block and do not have to be cleaned first.
• the holding rods are allowed to cool to about room temperature after being immersed in the paraffin bath and before the water lacquer is applied. In this way it is achieved that the paraffin layer solidifies on the holding rods and under no circumstances can any components of the paraffin get into the anti-corrosion agent bath. Since the anti-corrosion agent bath is at room temperature, it may also be sufficient if the holding rods are brought to room temperature only when immersed in the anti-corrosion agent bath, since the paraffin layer also solidifies when immersed.
• paraffins with a softening temperature of approximately 52 to 65 ° C., preferably with a softening temperature of approximately 52 to 54 ° C. have proven to be particularly suitable.
• the lowest paraffin consumption was around 0.8 to 1 g per holding rod.
• there was no difference between paraffin of greater purity namely AGN paraffin 1035 from Alfred Graf, Nuremberg, and raw paraffin 10107 from Deutsche Texaco AG, chemical division paraffins and waxes, Hamburg.
• the cost of raw paraffin is only about 1/3 of the AGN paraffin 1035, since raw paraffins contain 2 to 3% oil.
• Paraffins with softening temperatures of 52 to 54 ° are particularly recommended, since the paraffin is liquid over its entire length when the rods are pulled out, thus achieving the best separation effect.
• the holding rods are provided with a paraffin separating layer over their entire length, which can somehow come into contact with anti-corrosion agent or gas concrete.
• the holding rods with the steel reinforcement should only be immersed as far as necessary, as this leads to the best result of the separating effect. This also ensures that the anti-corrosion sleeve remains in the gas concrete when the holding rods are pulled out.
• the paraffin bath is expediently heated to a temperature of about 80 ° C and by suitable Measures such as heating and insulation are also kept at this temperature when the support rods are immersed.
• the procedure is such that, depending on the softening temperature of the paraffin, the bath temperature and the immersion time, taking into account any preheating of the holding rods, are set so that the thickness of the paraffin coating applied to the holding rods is approximately 10 to 50 ⁇ m, preferably approximately 20 to 25 ⁇ m,
• the last-mentioned layer thickness range corresponds to an amount of approximately 0.8 to 1 g of paraffin per holding rod.
• the present property right is also intended to use paraffin, which is solid at room temperature and has a softening temperature of about 50 to 70 ° C, preferably 52 to 54 ° C, as a release agent for holding rods for the steel reinforcements in gas concrete production, the holding rods and the steel reinforcements are provided with an anti-corrosion coating made of water-based paint after the release agent has been applied.
• paraffin which is solid at room temperature and has a softening temperature of about 50 to 70 ° C, preferably 52 to 54 ° C

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Mechanical Engineering (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)
• Paints Or Removers (AREA)
• Reinforcement Elements For Buildings (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=6374972

Family Applications (1)

Country Status (5)

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• 1989
  • 1989-02-25 DE DE3905973A patent/DE3905973C1/de not_active Expired - Fee Related
• 1990
  • 1990-02-05 EP EP90102209A patent/EP0385131B1/de not_active Expired - Lifetime
  • 1990-02-14 US US07/479,947 patent/US5043124A/en not_active Expired - Fee Related
  • 1990-02-21 DD DD90338026A patent/DD292902A5/de unknown
  • 1990-02-21 AU AU50022/90A patent/AU624910B2/en not_active Ceased

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