RU2762015C1 - Sleeper soles for dry concrete - Google Patents

Abstract

FIELD: railway transport.

SUBSTANCE: group of inventions relates to the field of the railway track structure, in particular, to soles of concrete sleepers, as well as to concrete sleepers with such a sole. The sole comprises an elastic plastic layer and a fibrous layer. The fibrous layer is made with recesses on the side facing away from the plastic layer. The bottom of the recesses is located between the top of the plastic layer and the top of the fibrous layer. The fibrous layer comprises hardened areas directed from the plastic layer to the top of the fibrous layer. The sole is pressed into fresh concrete with the upper side of the fibrous layer. The concrete element is compacted by vibration.

EFFECT: security of connection of the concrete element and the sole is increased.

7 cl, 2 dwg

Description

The invention relates to a sole for a concrete element, in particular for a railway sleeper, which is reinforced, non-stressed or non-reinforced. In particular, this element is a prestressed concrete element.

In known connection systems between textile fiber structures and concrete, such as, for example, railroad sleepers made of prestressed concrete or concrete, technical solutions are known in which fibers are connected to concrete structures in a force-locked manner (see EP-B-1 290 252 and EP-B-2 545 219 or WO-A-2011/110669).

In some known systems, for example, elastic plastic layers are fixed on the underside of railway sleepers by means of a layer of entangled fibers, while the textile layer of entangled fibers is both glued or welded inside or on the plastic layer, and is connected (embedded) in the concrete by incorporating fibers into a grout or a separately applied joint material such as an adhesive.

Non-woven fabrics are used as layers of entangled fibers for the connection between the exemplary railway sleepers and the elastic sole of the sleepers.

Many known nonwovens, as well as other bonding media, such as geogrids, in the case of concrete having a low water-cement ratio, have only limited properties for application with force-locking, providing unrestricted functionality of the bond. Namely, between the bonding medium (for example, non-woven material) and the concrete, defect spots can occur, which, for example, impair the desired, certain elastic characteristics and which, when exposed to water, lead to pumping effects, and also do not provide the strength required by the railroad across the entire surface. to take off.

Known nonwoven fabrics and nonwoven fabrics of entangled fibers (bonding media), when applied by vibration to relatively dry fresh concrete of sleepers, allow only limited penetration of the cement-water slurry into the bonding medium.

A waterproof membrane is known from WO-A-2011/033122. DE-A-32 20 768 describes a method for producing shaped pieces from fibrous nonwovens provided with a structured decorative layer. From DD-A-262 795, a method of making sheets for cleaning purposes is known.

The object of the invention is to provide a sole for a concrete element, in particular for a railroad tie, which is connected to the concrete element with greater reliability even when it is made of relatively dry fresh concrete.

To solve this problem, the invention provides a sole for a concrete element, in particular for a railway sleeper, which is provided with

- having an elastic plastic layer on top and

- located on the upper side of the resilient plastic layer and also bonded to the resilient plastic layer of entangled fibers;

the entangled fiber layer on its upper side facing away from the plastic layer has, in particular, groove recesses, which have a bottom lying between the upper side of the entangled fiber layer and the upper side of the plastic layer and projecting sidewalls therefrom;

the layer of entangled fibers, in particular thermally, is strengthened in its edge regions adjacent to the sidewalls.

The invention is based on the well-known fact that the fibrous (for example, entangled fibers) layer must be locally strengthened, so that in these strengthened places it can be "introduced by vibration" also into relatively dry fresh concrete. This does not necessarily require that the regions around the reinforced areas of the entangled fiber layer be deepened. Preferably, however, these reinforced regions are formed along the sidewalls, in particular the grooves, of the recesses.

In the context of this invention, "reinforcement" is understood to mean the joining of adjacent fibers. This bonding can be thermally induced when the adjacent fiber loops and the fiber ends of the entangled fiber layer in separate regions are heated, fused, and bonded together when cooled. But hardening can just as well be done, for example, by local application of an adhesive, which then passes through the matted fiber layer downward and strengthens the trapped fibers, connecting them together.

But, preferably, the hardening is realized by heat treatment. In addition to its own reinforcement, this also has the advantage that the matted fiber layer melts in the heat-treated areas and thus depressions are formed. It has proven particularly advantageous to run a heated object, for example a soldering iron, over the matted fiber layer, in which case grooves are formed, the bottoms of which lie at the height of the upper side of the plastic layer underneath the matted fiber layer. Alternatively, you can also work with hot air to "melt" the fibers.

Thus, the advantage of locally strengthening the matted fiber layer is that the matted fiber layer in these reinforced areas can more easily and reliably penetrate the relatively dry fresh concrete, and in particular by means of "vibration". Lying outside the depressions or, respectively, in other places between the reinforced regions of the matted fiber layer, the areas of the matted fiber layer, in which this layer retains its characteristics of entangled fibers, that is, its pliability, now, so to speak, are also "drawn" into the relatively dry fresh concrete. In this regard, it is preferable when the distance between adjacent reinforced areas lies within a few centimeters, for example in the range from one to ten centimeters, one to five centimeters and in particular one to three centimeters. In this case, the regions between the reinforced areas of the entangled fiber layer preferably have a width of one to ten centimeters, one to five centimeters, or one to three centimeters.

In a further advantageous embodiment of the invention, provision can be made for the bottoms of the recesses to lie at the height of the upper side of the plastic layer.

Further, it is advisable that the entangled fiber layer has a confining layer of entangled fibers, a circumferential edge region, which is thermally strengthened.

In another preferred embodiment of the invention, provision can be made for the hardening to take place thermally or by applying an adhesive.

One of the examples of implementation is shown in the drawings. This shows:

Fig. 1: sole for concrete element and

FIG. 2: A sole connected to a concrete element in accordance with FIG. 1.

Figure 1 shows a sole 10 for a sole of a concrete element 12 (see Figure 2), which may be a railroad tie.

Based on the discovered fact that the intrinsic moisture of fresh concrete under defined prescription conditions does not sufficiently penetrate through the fibrous layer 14 of the sole 10, the fibrous layer 14 is modified by means of geometrically defined depressions 16 (extrusions) and structural changes in the form of reinforcing elements, i.e. by means of the stiffening elements of the fibers 18 in such a way that for each technically possible concrete consistency a suitable connection can be obtained (see FIG. 1).

The fibrous layer 14 applied over the surface to the resilient plastic layer 20 (for example, in the form of an elastomeric plate) of the sole 10 is structured in accordance with the invention by means of geometrically defined depressions 16 (extrusions) in such a way that on the remaining raised regions 19 of the fibrous layer and / or on their edges 22 adjacent to the recesses 16, when concrete is applied, a higher rigidity of the fibrous layer takes place (higher specific pressure on the surface). In this case, the edges 22 of the remaining areas 19 of the fibrous layer are hardened, so that during the vibration application of the sole of the fresh concrete, a point-like area of increased humidity appears in the concrete surface, and this also in the case of relatively dry fresh concrete, and therefore opens up hitherto unavailable joining possibilities. between the environments "concrete" and "fibrous layer". The ends 24 of the recesses 16 can also be reinforced in this way.

In the case of the sleeper soles, which are called elastic bottom covers of railway sleepers made of concrete or, respectively, prestressed concrete, the elastic material of the plastic layer 20 is fused or, respectively, fused or glued onto fibrous mats forming or having a fibrous layer 14 having defined fiber properties.

This fibrous layer 14, after one-sided attachment (for example, approximately half of the inclusion) to the elastic material of the plastic layer 20, has a portion of fibers not included and therefore protruding from the plastic layer 20 upwards for attachment, i.e. embedding in a concrete sleeper (not shown in the drawing).

Reference numeral 26 shows the reinforced region of the fibrous layer 14, which is formed, for example, by applying an adhesive 28 and at the same time by material joining adjacent fibers of the fibrous layer 14.

The specified free fiber fraction consists of the ends of the fibers and the loops of 30 fibers. When applied to fresh concrete for the production of a concrete sleeper in the formwork, they are enclosed by the cement binder and provide the basic bond strength.

This basic strength, at optimum concrete consistencies, allows a peel strength between the concrete and the sole of the resilient material of about 0.3 N / mm ² - 0.5 N / mm ² to be obtained. These values are within the normal range of technical requirements of railway operators, but in the case of extremely dry concrete cannot be achieved with the required reliability.

With the proposed invention structuring the fibrous layer 14, this layer is removed by thermal extrusion in the volume of its fraction of fibers not included in the elastic plastic layer 20, that is, in the volume of its layer thickness lying on the plastic layer 20 (protruding fibrous coating), for example, at a distance approx. 1 cm, so that depressions 16; the edges 22 of the fibrous layer 14 are thermally strengthened, for example. The geometry of the resulting spatial structure of the remaining fibers, areas without fibers and reinforced areas is oriented towards the composition of the concrete, its consistency and different, depending on the specifics of the method, input by means of vibration when applied to the surface of fresh concrete.

Strengthening of the fibrous regions is preferably carried out by heat treatment of the fibers, whereby adjacent fibers, for example, are "welded" together. Locally created fibrous reinforcement elements allow the fibrous layer to be embedded in the fresh concrete when the sole 10 is pressed into the fresh concrete of the concrete member 12 (by vibration if necessary) (FIG. 2).

Experiments and tests have shown that peel strengths are achieved, the maximum values of which were about twice the traditional measurements, and which, as minimum values, provided values about 50% higher than the known normal values.

LIST OF REFERENCE SYMBOLS

10 Outsole

12 Concrete element

14 Fibrous layer

16 Grooves

18 Fibers

19 Areas of fibrous layer

20 Plastic layer

22 Edges

24 Dona

26 hardened areas

28 Glue

30 Loops of fibers.

Claims (10)

1. A sole for a concrete element, in particular for a railway sleeper, including - a resilient plastic layer (20) with an upper side and - a fibrous layer (14) located on the upper side of the elastic plastic layer (20) and also connected to the elastic plastic layer (20), - in this case, the fibrous layer (14) on its upper side facing away from the plastic layer (20) has recesses (16), which have a bottom (24) lying at a height between the upper side of the fibrous layer (14) and the upper side of the plastic layer (20) and sidewalls protruding from it upwards, while the fibrous layer (14) is reinforced in its sidewall-forming recesses (16) and / or in its edge regions (22) adjacent to the sidewalls (16), and / or on the bottoms (24) of the recesses (16) and / or wherein the fibrous layer (14) has reinforced regions (26) that extend from the plastic layer (20) to the top side of the fibrous layer (14). 2. A sole according to claim 1, characterized in that the bottoms (24) of the recesses (16) lie at the height of the upper side of the plastic layer (20). 3. A sole according to claim 1, characterized in that the fibrous layer (14) has a circumferential edge region, which delimits the fibrous layer (14), which is reinforced. 4. The sole according to one of the paragraphs. 1-3, characterized in that the strengthening of the regions (26) of the fibrous layer (14) is carried out thermally or by applying an adhesive (28). 5. The sole according to one of the paragraphs. 1-4, characterized in that the recesses (16) are grooved. 6. The sole according to one of the paragraphs. 1-5, characterized in that the fibrous layer (14) is a layer of entangled fibers. 7. Application of the sole according to one of paragraphs. 1-6 for a concrete element (12), while in fresh concrete, which, if necessary, is relatively dry, the sole (10) with the upper side of its fibrous layer is introduced, pressed, vibrated or similarly embedded in fresh concrete.

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