DE746556C - A tube consisting of a core tube with prestressed reinforcement and a jacket tube - Google Patents

Description

From a core tube with prestressed reinforcement and a jacket tube existing pipe The production of pipes from hardenable compounds, such as concrete, which are prestressed inside with an embedded in the wall of the pipes Reinforcement is provided, if not in accordance with the method of F r e y s s i n e t (patent 657I55) is worked in three work steps in such a way, that first the core tube is made, then the reinforcement on this under prestress applied and thereby placed the core tube under compressive stress and finally the jacket pipe on, the tied core pipe provided with the prestressed reinforcement is applied.

As a material for the core tube and also for the jacket tube so far only concrete. But now occur with these prestressed concrete pipes both a number of peculiar evils in their manufacture and in operation on. After the core pipe has been made from concrete and 'after the pre-stressed This inner part of the pipe is no longer reinforced radially inwards resilient core body. A cladding layer is now made on this core body Concrete applied, which essentially has the purpose of the prestressed iron reinforcement to cover and to protect against corrosive influences, so this coat layer has of concrete when setting as a result of the shrinkage of the concrete, the tendency to become to contract radially. However, this is where it becomes through the unyielding core body prevented, so that as a result of these radially directed forces in the material of the Mantle tensile forces occur, which the concrete is not able to cope with, so that already during the manufacture of the mantle, shrinkage fissures occur in it, through which through the prestressed iron reinforcement is exposed to corrosive influences: If such a pipe is now stressed by high internal pressure during operation, it is the negative pressure caused by the tension in the material of the core tube tension consumed, and mater further loading of the prestressed iron reinforcement (rejects the core tube. Now the concrete layer is wedge-shaped Has compressive prestress, it is due to this due to the expansion of the core tube caused tensile stress continues to be stressed in such a way that the already glue manufacture the hairline cracks that have occurred in the jacket pipe are enlarged and further giants 'Jacket pipe arise so that now despite. Sufficient durability of the core tube the purpose of the jacket pipe, namely to protect the prestressed reinforcement, is more or becomes less illusory.

Another notable shortcoming of these prestressed concrete pipes is because the jacket roll does not or only poorly adheres to your core tube, so that. there is a more or less continuous separating layer between the two. These Adhesion through special measures, such as roughening the core tube, profiling To improve the outer skin or similar things either requires a special one Work step or a difficult production of the core tube. In addition, it is so far did not succeed, a really flawless method for the @ #, applying the concrete coating to develop.

Uni to avoid all these disadvantages is now according to the invention proposed such, a prestressed reinforcement supporting core tubes by a Covering a coat made from mixed with fillers or containing inserts Bitumen or tar. Although there are already multi-layer tube e known at which reinforcement completely embedded in the concrete is provided and at which on this concrete layer containing the reinforcement either an outer or an inner insulating layer of tar o. (-l. materials applied and then it is optionally covered by another concrete jacket. l3 ei this Multi-layer pipes, however, are completely within the concrete layer arranged reinforcement not uni a prestressed reinforcement, and continue to lie here di- tar insulation layers only on the completely smooth outer or inner surface layer of the concrete: In contrast to this, the subject of the invention the prestressed reinforcement is provided on the outer surface of the core tube, o (ah their free surface when the jacket pipe layer is subsequently applied is covered. By the fact that the bitumen made from filled or inserts or tar or the like existing.e jacket pipe layer that located between the two layers Covering reinforcement, the reinforcement creates an extremely intimate connection, adhesion and anchoring between the concrete surface of the core pipe and the 'dantelrohrschicht guaranteed, and continues to be entirely or largely in the jacket pipe layer lying reinforcement of this relatively sensitive layer an increased `` Resistance granted, so that those made of fillings or containing inserts Bitumen or tar existing casing pipe layer both during manufacture and all _ \ nfi »- changes during operation, for example due to pressure loads of the core tube made of concrete or a Zernent fiber mixture be able to meet without risk of cracking. The thickness of the jacket pipe layer from filled bitumen or tar containing deposits is dimensioned in such a way that dal.l the reinforcement strands or iron are safely covered. For example, if such . Covering with a thickness of around 3111111 is considered sufficient and the reinforcement twist has a thickness of 2 minutes and is wound crosswise, see above finitely, a jacket pipe wall of about 7 nm in total thickness can be expected, while a casing pipe made of concrete in the same case would have to have a wall thickness of about 20 mni, so that, in contrast, also the total weight of the tube in the subject of the invention is significantly reduced, set. The special requirements that a jacket pipe made of bitumen or tar during manufacture, storage and installation has, according to your current state of technology, can well correspond to «ground. Succeeds yes, bitumen or tar, for example with suitable additives, 1 # aseistoffen, Rock powder, slag wool, etc. to fill and thus the softening and freezing point of the masses so far apart that they fully meet the practical requirements suffice.

For example, masses based on bitumen or tar can be produced, which have a freezing point of -5 ° with an Er - @% - calibration point of -1- 9o '.

The application of the essentially consisting of bitumen or tar Jacket tube can preferably be done in such a way that previously on the core tube Cement-containing and covering paint, for example with benzene as a solvent, applied is. The main mass, which has a doughy consistency, can then be placed on this surface can have, troweled on «earth. i A method is particularly advantageous in which the casing pipe mass in heated Conditioned through a pipe under pressure -A funnel is fed and pressed onto the rotating core tube.

. The edges of the funnel can. the outer surface to be produced correspond, and the funnel surface itself can be curved so that it takes the pressure, under which the mass is at the feed, increased on the pipe jacket.

The consistency of the mass can be determined by its state of heat and where appropriate can be regulated by heating the funnel. The regulation can go so far, that the mass is fed in without pressure and the funnel widened to form a guide plate whose width corresponds to the entire length of the pipe.

Since the pipes at their spigot ends, when caulked in the sockets, Particularly high loads have to be absorbed by the manufacture of Special attention should be paid to the jacket pipe in this part. However, they are To take over requirements from the proposed masses.

It is particularly advantageous to use the socket seal of caulking or casting compounds, which are also based on bitumen or tar are constructed, for example Mundit. When @% originates with such masses a particularly intimate connection between the tail end of the pipe and the sealant.

In addition, it is also possible to use the jacket pipe layer from bitumen mass or the like. In a manner known per se, another thin one To cover a hard shell, for example made of concrete or a cement-fiber mixture. In this In the event, the strength of the bitumen jacket pipe can be further reduced, especially since then hardly any value is placed on a uniform outer profile. For the application such a jacket of only a small thickness, for example to about 2 mm can be measured, a method is particularly recommended, whereby the bitumen mass is sprayed on.

Claims (1)

PATENT CLAIM: From a core tube made of concrete or a cement-fiber mixture with pre-stressed reinforcement applied to this and one covering the reinforcement Jacketed pipe existing pipe, characterized in that the jacket pipe from with Bitumen or tar mixed with fillers or containing deposits.