Concrete Sleeper for High Dynamic Loads and Method of Manufacturing the Same
Concrete sleeper for high dynamic loads having rail support surfaces (2) and a lower sole region, consisting of a high-strength standard concrete (4) capable of withstanding high compression forces, whereby the rail support faces (2) and/or the lower sole region consist(s) of a wear-resistant, abrasion-resistant or tension-resistant material.
The invention relates to a concrete sleeper for high dynamic loads with rail support surfaces and a lower rail region, consisting of a high-strength standard concrete capable of withstanding high compression forces.
In the case of high dynamic loads, the phenomena of wear and/or abrasion frequently occur in the rail support regions and on the underside of the concrete sleepers. This wear is brought about by the compression of plastics layers inserted between the rail and the concrete body of the concrete sleeper, or by the shifting of grains in the ballast bed underneath the concrete sleeper. Such abrasion phenomena may also arise for example due to the braking of the enormously long trains used in the USA and Australia, which may displace the welded rails by a few millimetres, naturally leading to corresponding abrasion action on the concrete sleepers.
In the case of pulsating vertical load, the plastics layers are also expanded and contracted in the horizontal direction and consequently rub against the concrete surface of the sleepers. On the underside of the concrete sleepers, again the ballast grains rub against the concrete body. This results in the removal of material at the rail support points and on the underside of the concrete sleeper. Consequently, the geometry and carrying capacity of the concrete sleepers is sufficiently impaired over time that these are no longer fit as safe, stable supporting elements.
The object of the invention is therefore to create a concrete sleeper of the type mentioned in the introduction which counteracts these properties of wear at minimal cost.
To achieve this it is proposed according to the invention that rail support
surfaces and/or the lower sole region consist(s) of a wear-resistant, abrasion-resistant or tension-resistant material.
In addition, the invention relates to a method of manufacturing a concrete sleeper of the type described.
It may be provided according to the invention that the wear-resistant, abrasion-resistant or tension-resistant material is inserted as a prefabricated plate or profile into a sleeper mould below or on the standard concrete and bonds therewith as this hardens.
The wear-resistant, abrasion-resistant or tension-resistant material may be an inserted metal angle, for example.
According to an alternative embodiment of the invention it can be provided that the wear-resistant, abrasion-resistant or tension-resistant material is bonded and hardened wet-on-wet with the standard concrete in a sleeper mould, in that according to the type of placing in the sleeper, first the wear-resistant, abrasion-resistant or tension-resistant material is inserted into the sleeper mould as a special concrete material and then the standard concrete is poured in or conversely the standard concrete is poured in first and then, to form the wear- and abrasion-resistant sole, the special concrete material is introduced into the sleeper mould as the top layer.
According to the invention, in this method, by introducing the different plastic concrete materials directly one after another, wet on wet, the standard concrete and the special concrete material can be mixed together in their border region by shaking or vibrating in such a manner that they form a monolithic body, but one which has over its height the desired differing bending tensile strength or abrasion-resistance.
Alternatively, in a development of the method according to the invention, it can be provided that a preferably prefabricated plate composed of plastics material is used, the plate preferably being inserted in the liquid or still-plastic form into the concrete mould and in this state forming a bond with the concrete.
Further advantages and details of the invention will appear from the following description of some embodiments and from the drawings, which show:
In
In
In the embodiment according to
Finally,
The invention is not limited to the embodiments shown. Due to the different use of abrasion-resistant or wear-resistant special types of concrete and tension-resistant concrete in different regions of the sleeper, for example, the modification which increases tensile strength according to
Claims
1. Concrete sleeper for high dynamic loads having rail support surfaces and a lower sole region comprised of a high-strength standard concrete capable of withstanding high compression forces wherein the rail support faces and/or the lower sole region comprises a wear-resistant, abrasion-resistant or tension-resistant material.
2. Concrete sleeper according to claim 1, characterised wherein the wear-resistant, abrasion-resistant or tension-resistant material is a prefabricated plate or profile or a metal angle, in particular a steel angle
3. Concrete sleeper according to claim 1, wherein the wear-resistant, abrasion-resistant or tension-resistant material is a concrete layer bonded to the standard concrete and/or is a special concrete.
4. Method of manufacturing a concrete sleeper for high dynamic loads comprised of a high-strength standard concretes capable of withstanding high compression forces, having rail support surfaces and a lower sole region, the rail support surfaces and/or the lower sole region is/are manufactured from a wear-resistant, abrasion-resistant, or tension-resistant material, which is inserted into a sleeper mould below or on the standard concrete as a prefabricated plate or profile and bonds to the standard concrete as this hardens.
5. Method of manufacturing a concrete sleeper according to claim 4, wherein a metal angle, in particular a steel angle, is inserted as the wear-resistant, abrasion-resistant or tension-resistant material.
6. Method of manufacturing a concrete sleeper according to claim 4, wherein the wear-resistant, abrasion-resistant or tension-resistant material as a first concrete layer and/or as special concrete is bonded to the standard concrete wet-on-wet in a sleeper mould and is hardened.
7. Method of manufacturing a concrete sleeper according to claim 6, wherein different types of concrete are introduced one after another into the sleeper mould and are mixed in the border region by shaking or vibrating in order to form a monolithic body.
8. Method manufacturing a concrete sleeper according to claim 4, wherein a preferably prefabricated plate of plastics material is used.
9. method of manufacturing a concrete sleeper according to claim 8, wherein the plate is introduced into the sleeper mould in a liquid or still-plastic form and in this state forms a bond with the concrete.
Type: Application
Filed: Nov 25, 2005
Publication Date: May 8, 2008
Inventor: Stephan Freudenstein (Neumarkt)
Application Number: 11/664,163
International Classification: E01B 3/28 (20060101);