BG228Y1 - Prestressed concrete sleeper - Google Patents

Abstract

The sleeper is used for building of rail tracks. Itaccurately positions the fasteners by making use of the stressedreinforcement itself. Stresses during operation are transmittedwithout the appearance of any cracks in the sleeper, and theirtransmission to the ballast lay has no stress concentration in itas there are multiple cone-like projections along its lowersurface which enable its even distribution. The sleeper includes aconcrete body (1) with prestressed reinforcement (2) which issymmetrical to the ... , and close to it it is prismatic. Body (1)has two end parts with increasing section (3) to its ends havingparts (4) protruding under it representing multiple truncatedcones. The stressed reinforcement (2) is U-shaped folded havingends (5) unilaterally anchored to the sleeper having two discsprings (11) turned against each other and a nut (12). Body (1) ismade of disperse reinforced fibrocement concrete and dowels arefixed in it. At the end parts there are under-rail seats (6) withside rests (7) along their upper surfaces. The dowels have theform of bushings (8) with internal (female) threading (9) andlateral holes (10) through which the reinforcement (2) passesfitted in a horizontal plane.2 claims, 3 figures(11) 229

Description

The utility model refers to a prestressed concrete cross beam that will find application in the construction of railways for rail vehicles.

BACKGROUND OF THE INVENTION

A pre-stressed concrete cross beam is known, comprising a pre-stressed reinforced concrete body, which is a concrete body symmetrical to a railway axis, adjacent to which is prismatic and has an extended section at both ends. The tense reinforcement is bent U-shaped and is located in an approximately vertical plane and has edges anchored to one side of the beam. The lower surface of the beam is flat or, as an embodiment, with two symmetrically protruding parts below the expanded section at both ends. For fixing the fasteners for the rails are used dowels, concreted when pouring the body of the beam (1).

The disadvantages of the known traverse are that during operation there is a possibility of cracks in both the longitudinal direction and around the fasteners. It is also possible to move the dowels during the processing of the concrete mixture in the formwork forms or to easily break them during the operation of the road, which in turn leads to laborious operations for dismantling and installing new ones. In addition, the presence of a smooth upper surface of the traverse necessitates the use of a number of additional devices to absorb the resulting forces and to convey them through the traverse at the base when locking the track in place. Despite the presence of the downward projections at the edges of the beam, the adhesion to the ballast base is relatively small, since part of the entire surface steps on points formed by the individual grains of the ballast.

The technical nature of the utility model

The object of the utility model is to create a pre-stressed concrete cross beam, the construction of which avoids cracks, allows accurate positioning of the fasteners and increased safety in the movement of vehicles.

This task is accomplished by a pre-stressed concrete cross member comprising a pre-stressed concrete reinforcement body which is symmetrical with respect to the railway axle, in proximity with which it is prismatic and has two end portions extending to the edges of the cross section with projections below it. The tense reinforcement is bent U-shaped and has edges anchored unilaterally on the beam, and dowels are fixed in the concrete body. According to the utility model, the concrete body is made of fiber reinforced fibro-cement concrete, with the two end sections rising to the edges having sub-rails sockets with lateral stops formed on their upper surface. The dowels are bushings with internally threaded and transverse openings through which the U-shaped bent reinforcement extends in a horizontal plane and the ends of which are anchored by two opposite springs and a nut. The protruding parts below the growing towards the edges are a plurality of truncated cones.

It is appropriate that the growing section of the concrete body be formed in a horizontal projection by linear law.

The advantages of the utility model are the achieved ability to accurately position the fasteners by using the tension reinforcement itself. There is also a transfer of the effort that arises during operation without cracks in the beam, due to the use of dispersion-reinforced fibro-cement, as well as the presence of track rails on the upper surface of the beam. On the other hand, the transfer of force to the ballast base does not lead to a concentration of stresses in the beam, since the numerous conical protruding hours2 on its lower surface allow them to be distributed evenly by increasing the contact surface with the ballast grains. Pre-tensioning in the region of the ends of the reinforcement is also avoided by the possibility of straining it in place by means of spring nuts.

Explanation of the figures

The utility model is illustrated by an exemplary embodiment illustrated in the accompanying drawings, where:

Figure 1 is a top plan view of the traverse according to the utility model;

FIG. 2 is a longitudinal section through the cross-section of AA from FIG. 1;

3 is a view of B of FIG. 2.

Examples of implementation of the utility model

The prestressed concrete beam comprises a concrete body 1 with pre-stressed reinforcement 2, which is concrete body 1 symmetrical with respect to the railway axle, adjacent to which is prismatic and has two end portions extending to the edges of the cross section 3 with projections 4 below it. The tensile reinforcement 2 is bent U-shaped and has ends 5 anchored unilaterally on the beam. Dowels are fixed in the concrete body 1. The body 1 is made of disperse reinforced fibro-cement, and the two end sections, extending towards the edges 3, have on their upper surface sub-rail sockets 6 with lateral stops 7. The dowels are bushings 8 with internal thread 9 and cross-holes 10 through which it passes. The U-shaped bent reinforcement 2, which is arranged in a horizontal plane and whose ends 5 are anchored by two counter-splined springs 11 and a nut 12. In the shown embodiment, the springs 11 and the nut 12 are arranged in specially formed sockets 13 in the body 1. The protruding portions 4 below the rising towards the edges 3 are a plurality of truncated cones.

It is good that the upstream section 3 of the concrete body 1 is formed in a horizontal projection by linear law.

Application of utility model

The utility model is applied by first making the cross-section of specialized formwork forms (not shown in the figures). The pre-stressed U-shaped bent reinforcement 2 is pre-housed therein and the metal bushings 8 are threaded through it through the transverse openings 8 and fixed at their respective places 8. After the concrete body 1 on the beam has gained the required strength, the U-shaped reinforcement 2 is tensioned by tightening the nuts 12 on the disc springs 11 in the sockets 13.

Traverses thus made are applied in the usual way for forming a traverse grill by arranging them apart from one another and placing rails (not shown in the figures) in the track rails 6 between the stops 7. The rails are fixed in their places by terminals with bolts or dowels. joints (not shown in the figures) in the metal bushings 8. The bushings 8 are counteracted by the U-bent pre-stressed reinforcement 2, which prevents the bushings 8 from turning over during screwing.

The rail grill is then applied to the ballast prism, whereby the protruding cone-shaped portions 4 enter between the ballast grains and provide increased traction and corresponding transverse resistance against displacement during rail temperature fluctuations.

As the rolling stock moves on the track, the U-bent reinforcement absorbs the tensile forces from the bending moment. The horizontal force is distributed evenly over the supports 7. The solidity of the concrete body 1, as well as the use of a special type of concrete, namely fiber cement with different fillers, ensures rigidity and reduces the possibility of cracks during installation and operation.

Claims

Claims (2)

1. Pre-stressed concrete beam comprising a pre-stressed concrete body, which is a concrete body symmetrical to a railway axle, in proximity to which is prismatic and has two end portions extending to the edges of the cross section, with projections below it, such as reinforcement is bent U-shaped and has edges anchored unilaterally on the beam, and in the concrete body are fixed dowels, characterized in that the concrete body (1) is made of dispersion-reinforced fibro-cement concrete, with the two end parts having ascending to the edges (3) have padded sockets (6) with lateral stops (7) formed on their upper surface, and the dowels are bushings (8) with internal thread (9) and with transverse openings (10) through which it passes. U-shaped bent reinforcement (2), which is located in a horizontal plane and whose ends (5) are anchored by two inverted disc springs (11) and a nut (12), with the protruding parts (4) below the rising to the ends of the section (3) represent a plurality of truncated cones. Traverse according to claim 1, characterized in that the concrete body extending towards the edges (3) is formed in a horizontal projection by linear law. Attachment: 3 figures