DE1049889B - - Google Patents

Description

This invention is intended to have some significant deficiencies in the previously known reinforced concrete sleepers remove.

In recent years, considerable efforts have been made in various European countries to to replace the wooden and concrete sleepers that have been used for many decades. Included one could make use of the high compressive strength of concrete «. However, it caused great difficulties the relatively low flexural strength and torsional strength This is where the greatest danger arises for concrete swelling, namely the formation of cracks, especially in the middle the whole Lisge camp without high demands on the bedding, without causing difficulties. At dffi concrete sleeper, on the other hand, a wide variety of suggestions have been made to address the above Disadvantages * to switch without, however, having found a fully satisfactory result.

First, monolithic reinforced concrete sleepers were developed, although they were slackly reinforced and prestressed. The middle section was set off more and more upwards in order to limit the sleeper support surface and thus the moments in the vicinity of the rails and to relieve the particularly endangered middle section. In addition, the ballast bed was deepened under the side part.

In order to maintain this vital condition, noise observation and maintenance work are required necessary With this, however, the danger of cracking could not be completely eliminated. At an entrance threshold, the generally recognized requirement is placed that the threshold ends elastic and adjust about 5 to 10 mm in height and about their longitudinal axis must be able to twist elastically to a certain extent, and with sufficient frequency.

The appreciation of the rigidity of monolithic reinforced concrete by reducing the cross-section there are any differences, because the middle part is practically never entirely dependent on bending moments, in spite of all! can be.

It was also proposed to connect two concrete blocks, reinforced with a central piece, with a central piece. The resulting availability of the threshold is, however, not elastic and the required dimensional accuracy is not achieved as a result. Therefore, the SchwellefiSihaitte attempt was made to hold, by elastic intermediate members to verbiMeund by a solid-Längsbe Wehrung ¹ Sftiflmen.

All VS & would be above articulated reinforced concrete sleepers are jedi> cP »xigel ^; remained stuck and therefore did not penetrate yfifaxis.

Railway sleeper with two prestressed concrete blocks that serve as supports for the rails and a middle part made of sectional steel connecting them

Applicant: Dr.-Ing. Kurt Schmidt, Berlin-Lichterfelde West, Hortensienstr. 19th

ir

Furthermore, the method should be mentioned, two slack reinforced concrete blocks through a continuous T-profile iron rigidly to connect, which has so far been introduced especially in France. This suggestion is still the cheapest in terms of the endangerment of the central part. However, the technical and economic advantages of the pre-tensioning dispensed and an extremely careful sleep reinforcement of the two Blocks are made.

The same applies to some proposals (Swiss patent specification 110 435, French patent specifications 543 275 and 618 297), in which the sleepers are already made of individual parts with concrete blocks and these connecting tie rods exist. The blocks are not pretensioned and only contain a slack reinforcement.

Finally, according to German patent specification 594 954, the concrete sleeper is to be named, which consists of two concrete blocks which are held together by a tie rod. With this pole was one Prestressing in the usual sense today (up to 20 t and above) cannot be achieved and is not intended, and tracking was not guaranteed to a sufficient extent. That resulted from the application a common tie rod for tensioning (not pretensioning) and tracking.

In the present invention it has now been assumed that the method of prestressing two concrete blocks and to be connected by a profile iron is preferable to all other principles. The threshold consists of two concrete blocks, a middle part and tension anchors. The pre-tensioning concrete blocks Prestressing steels are - menscite of the blocks on that

BATH ORIGINAL

809 748/98

Claims (2)

Middle part fastened by a screw coupling, which also serves to introduce the pre-tensioning force into the blocks. A reinforced concrete sleeper designed in this way has the following essential advantages over those previously known: The generally recognized advantages of prestressing are not an issue. In contrast, the disadvantageous monolithic shape is avoided. The blocks are each pretensioned for me, so the middle part is not. On the one hand, this had the advantage that the pre-tensioning can be smaller than with a continuous tensioning device, because excessive pre-tensioning with regard to the endangered central part is no longer necessary. On the other hand, there is no risk of cracks forming in the central part or in the transition from the central part to the blocks, which, among other things, can lead to the preload slipping. Furthermore, it cannot happen that the middle part, which is relatively small for the reasons given above, creeps and the preload is reduced as a result. The control of the prestressing is of course an extremely important prerequisite for prestressed concrete sleepers, and the invention largely meets this requirement. A threshold designed in this way also offers the advantage that it consists essentially of four individual parts which are interchangeable. There are two blocks, the middle part and the tie rods. For example, if a block near the rail bearing has been damaged in an impermissible manner, it can be replaced by another. The same goes for the middle section and the tie rods. The last-mentioned advantage could also be expanded by transporting the sleepers in individual parts, in contrast to the previous method. This would bring significant savings in cargo space and enable the sleepers to be loaded and unloaded by hand, for example. Furthermore, the separate design of the tensioning anchor and the middle part, compared to the one-piece construction, has the significant advantage that both parts are made of suitable materials according to their very different tasks. The anchors are expediently made from spring steel and the middle part from profile iron, possibly from old material. All other solutions cause difficulties, so the use of spring steel as well as profile iron for anchor and middle part at the same time. In the drawings, some embodiments of the invention are shown, namely Fig. 1 is a side view of a sleeper. Fig. 2 is the associated plan, Fig. 3 is a section AA with a tensioning and connecting anchor and two sleeper screws per block, Fig. 4 is a section AA with two tensioning and connecting anchors and four sleeper screws per block, Fig. 5 is an enlarged view of the Connection between the left block and the middle part of FIG. 2 with a tensioning and connecting anchor and a pipe as a central part, FIG. 3 similar to FIG. 5, but with two tensioning and connecting anchors and a pipe as the middle part. The assembly of the levitation can be done in different ways. Two examples of this: 1. The concrete blocks 1 are manufactured individually, with the sleeper screws 2 and the tensioning anchors 3 have already been poured in, namely the sleeper screws 2 firmly and the tensioning anchor 3 in the known Way with bitumen paint. The tensioning anchors 3 are practical, as indicated in FIGS. 3 and 4 Play-free through the loops 4 of the sleeper screws 2. Then the protruding from the blocks Threaded ends 5 of the tensioning anchor 3 with the middle part 6 up to the necessary bias in already screwed in a known way. The middle part 6 has transition pieces 7 at both ends between the transition pieces 7 and the end faces of the concrete blocks 1 can be rubber liners in a known manner are provided, furthermore spacers to widen the track. 2. The concrete blocks 1 are manufactured individually, with the sleeper screws 2 already firmly cast and 3 holes have been left for the tensioning anchors, into which they fit with practically no play. The tensioning anchors 3 are then firmly screwed to the middle part 6 and through the holes of the concrete blocks pushed. Then the required Preload initiated. (Otherwise see example 1.) This invention should not deal with already known details of production, such as material selection, Dimensioning, initiation of prestressing etc .. deal. On the other hand, the invention is limited not on the illustrated and described designs. These are only given as examples. One or more tensioning anchors 3 can be used, and the central part can consist of one or more Profile iron exist without departing from the scope of this invention. The same applies to the case that one chooses a different rail fastening than the one proposed here. Claim: Railway sleeper made of two prestressed concrete blocks that serve as supports for the rails and a central part connecting them made of sectional steel, characterized in that one or several prestressing steels (3) arranged in the concrete blocks (1) on the one or more Sectional steels existing middle part (6) are fastened by a screw connection (5), which is preferably is arranged on the inside of the concrete blocks, the screw connection at the same time serves to introduce the pre-tensioning force into the concrete blocks. Considered publications:
German Patent No. 594 954;
Austrian Patent No. 17,809;
Swiss Patent No. 110 435; French Patent Nos. 543 275, 594 196, 618 297, 993 422; British Patent No. 508,322;
U.S. Patent No. 1,436,847. For this purpose, 1 sheet of drawings BATH ORIGINAL