Railway sleeper made of concrete and fiber-reinforced stoneware

Abstract

Arrangement with a concrete railway sleeper that is stabilized on the underside or in the middle with a fracture protection plate for reinforcement.

Description

[0001] The present invention relates to the development of railway sleepers required for supporting and laying railway tracks, for example railway tracks, and their fastening and anchoring in the subsoil.

[0002] Such sleepers are typically located in the ballast bed and are usually laid at a distance of 2 / 3 meters.

[0003] The challenge in the construction of parts that could previously be manufactured from wood using relatively simple means must increasingly be made from artificial materials, since, against the background of climate change, which is no longer disputed, wood is becoming a scarce commodity for mass use.

[0004] Newer construction methods have shifted to concrete, which must be prestressed using structural means - for example, with steel or steel threaded rods cast into the concrete, which are put under pressure at the ends by means of nuts after the concrete has hardened - so that the concrete's lack of tensile stability is given by a fixed prestress reserve.

[0005] This is adjusted by the torque when tightening the nut. The disadvantage is that such threaded rods can either rust or, if they are made of stainless steel, break off or even lose some of their prestressing over time. The concrete can then become brittle and crack even faster, while moisture and frost and the changes in the concrete over time do the rest to destroy the sleeper and impair its load-bearing capacity. With concrete sleepers, cracks and hairline cracks are already taken into account during the dimensioning process, as they cannot be completely prevented in prestressed concrete - at least not on the tension side. In the required load tests, hairline cracks in the tension area are accepted as permissible. However, such cracks widen when exposed to frost cycles. Wooden sleepers do not exhibit hairline cracking but weather even faster.

[0006] The goal now is to build concrete sleepers that will no longer crack and thus last significantly longer, currently estimated to be twice as long. To this end, a reinforcement plate made of carbon fiber stone, for example, will be installed in the area of ​​the rail support. This plate is significantly stiffer than pure steel prestressing, which can still be used. If cracking is prevented, the steel reinforcement will also last several times longer without rusting.

[0007] The idea proposed here is to configure a sandwich of materials that largely solves the aforementioned problem areas simultaneously. The goal is to optimize permanent, unchanging load-bearing capacity and strength values, vibration damping, ease of processing with regard to the connection to the rail, crack-free long-term durability of the part itself, as well as structural durability and the possibility of integrating additional stability functionalities.

[0008] The present invention accordingly describes a sandwich composed of several slabs of natural stone or artificial stoneware, such as natural stone, glass, or ceramic, which are bonded together by means of an intermediate layer of fiber material and a connecting matrix—for example, epoxy resins or other adhesive-like crosslinking options. According to the invention, this composite of stone, fiber material, and resin is designed such that the fiber layers themselves prestress the stone slabs, eliminating the need for complex prestressing with threaded rods or steel tension rods. This prestressing should preferably be generated by a type of fiber that does not subsequently lose this prestress. Carbon fibers and stone fibers have proven to be the most suitable for this purpose, as described, for example, in EP 106 20 92. In principle, all possible types of natural stone can be used.

[0009] The reinforcement of concrete with carbon fibers and stone is described, among others, in EP3723976. The stone serves as an ideal force transmitter between the concrete and carbon, bridging the different thermal expansion coefficients and stiffnesses of carbon and concrete, since the respective coefficients of earthenware or glass lie almost exactly between those of the carbon matrix and the concrete.

[0010] For the first time for such an application of CFS (Carbon Fiber Brick) in a railway sleeper, a special plate structure has been developed which reinforces the sleeper in the area of ​​the rail support not only longitudinally but also transversely in order to prevent longitudinal cracking of the sleeper head, as was recently observed in accidents in track construction when the rails are exposed to increases in temperature for days and the acting forces become too great for conventional sleepers and tear them apart by the reinforced structure being blown up where the forces on the inner structure of the sleeper heads, which are usually only longitudinally reinforced, become so great that the sleeper heads tear lengthwise, allowing the rail to give way when high temperatures come into play and a train derailment becomes likely.

[0011] One of the many possible embodiments of the invention is described in Fig. Top view of an approximately 20 mm thick plate, whose upper and lower granite layers (1) are bonded to the matrix (2) via a fiber coating. The plate is arranged in the lower and / or middle area of ​​the sleeper's rail support and absorbs the bending forces and transverse forces. If necessary, such a plate can also be inserted in the middle of the sleeper in the upper area to absorb the bending forces in the other bending direction.

[0012] Fig. shows the body of the plate in Fig. in cross section F - F. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3723976

[0009]

Claims

[1] Arrangement with a concrete railway sleeper stabilized on the underside or in the middle with a fracture-resistant plate for reinforcement. [2] Arrangement with a railway sleeper according to claim 1, wherein the plate is made of earthenware with a fiber interlayer and connecting matrix (2). [3] Arrangement with a railway sleeper according to claim 1 and 2, - the stabilising fibre of the fibre interlayer is a glass fibre, carbon fibre, stone fibre, aramid fibre, natural fibre - such as flax, hemp, corn, cotton, wood, bamboo or other - possibly carbonised - plant fibre, steel fibre or other fibres or a mixture of these fibres, which are bound with the aid of resin and glued to the earthenware in layers - and the entire assembly is designed for use as a sleeper for railway tracks, characterized bythat the matrix (2) consists of hardening resins, for example epoxy resins, thermoplastic resins, synthetic resins, or bio-resins produced from regenerative plant materials, e.g. algae, - the earthenware is made of natural hard stone or other natural stone such as granite, marble, basalt, sandstone, slate or artificial stone such as concrete, resin-bound sand, quartz or stone flour, ceramic or glass, - and that the fiber layers are placed in the composite in such a way that they stabilize the overall composite in both horizontal axes in the longitudinal and transverse directions [4] Arrangement according to claims 1 to 3, characterized by that the reinforcement plate has recesses that ensure a firm bond in the concrete matrix. [5] Arrangement according to claims 1 to 4, characterized bythat the thermal expansion coefficient of the earthenware layer is smaller than the thermal expansion coefficient of the concrete to be stabilized and larger than the thermal expansion coefficient of the carbon fiber matrix. [6] Arrangement according to claims 1 to 5, characterized by that the stiffness of the earthenware layer is greater than the stiffness of the concrete to be stabilized and smaller than the stiffness of the carbon fiber matrix. [7] Arrangement according to claims 1 to 6, characterized by that the stone is a natural stone of the type basalt or gabbro, which as a plutonic rock has a high weathering potential due to CO2, which means that the products can become CO2-negative.

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