REMEDIATION OF CROSSTIE CRACKS

Abstract

The invention relates to a method and sealing agent for sealing cracks in concrete crossties of a railway rail, in particular in concrete crossties of a ballastless track, wherein the cracks have a width equal to or less than 1 mm. According to the invention, a mixture of an epoxy resin binder with quartz sand is used, wherein the quartz sand has a grain size of 0.1 mm to 1 mm.

Description

TECHNICAL FIELD

The present invention relates to a method and a sealing agent for closing cracks in concrete crossties.

PRIOR ART

Railway crossties are subjected to severe loads. They must therefore be replaced regularly. This is relatively cost-intensive and in addition leads to relatively long interruptions in the use of the railway track. In particular, in the case of what are called “ballastless railway tracks”, in which the crossties are cast, an alternative solution for remediation of the crossties is necessary.

It is known to use Icosit®, a 2-component epoxy resin binder, in the form of pourable mortar for fixing bolts and for grouting adhesive joints having a width of more than 1 cm. Stable epoxy resin mortar is used for sealing rail base plates, bridge bearings and machine foundations. Icosit® is offered by Sika.

DESCRIPTION OF THE INVENTION

It is an object of the invention to provide a simple, inexpensive and rapid method and a means for remediation of concrete crossties of a railway track.

This object is achieved by a method having the features of claim 1, and a sealing agent having the features of claim 9.

According to the invention, cracks in the concrete crosstie are filled with a sealing agent which consists of a pourable epoxy resin mortar. In this case the mortar is formed from a mixture of an epoxy resin binder with quartz sand. According to the invention, the quartz sand has a grain size from 0.1 mm to 1 mm. Preferably, the grain size is 0.2 mm to 0.7 mm, and more preferably 0.4 mm to 0.7 mm.

The sand used preferably has grains of diameters in the total stated grain size range. It is, however, also possible that a sand is selected, the grains of which only have diameters in a range smaller than the stated one. Examples thereof are ranges from 0.1 mm to 0.3 mm, 0.2 mm to 0.7 mm and 0.5 mm to 1 mm.

It has surprisingly been found that this pourable mortar is suitable for sealing very small cracks in concrete crossties. It has surprisingly been found that use of a finer grain size does not lead to a better result. The mortar is astonishingly also suitable for cracks, the width of which is no greater, or insignificantly greater than, the quartz sand grain size used. For instance, cracks of a width of equal to or less than 1 mm, in particular of 0.3 mm, 0.5 mm and 1 mm, may be filled and sealed.

As a result, in particular concrete crossties in ballastless railway tracks may be promptly remediated and need not be removed from the track.

Good results were achieved, when, apart from the binder and the quartz sand, no further component was added. Preferably, the epoxy resin binder and quartz sand are used in a mixing ratio of 1:1 weight percent.

Preferably, the epoxy resin binder is a 2-component agent. In particular, Icosit® from Sika has proved itself. Good results were achieved with Icosit® KC 220/60 TX.

In the method according to the invention, the crack that is to be sealed is preferably dried before it is filled with the mixture. For example, a propane thawing apparatus is suitable for the drying. Preferably, the pourable mortar is applied with a spatula onto and thereby into the crack, wherein it is spread along the crack.

Further embodiments and variants of the method are given in the dependent claims.

DESCRIPTION OF PREFERRED EMBODIMENTS

Icosit® KC 220/60 TX was mixed with quartz sand of the following grain sizes:

• a) 0.1 mm to 0.3 mm
• b) 0.2 mm to 0.7 mm
• c) 0.5 mm to 1.0 mm
• d)

The mixing ratio was in each case 1:1 weight percent.

Cracks of 0.3 mm, 0.5 mm and 1.0 mm were filled.

The depth of penetration of the pourable mortar thus mixed was always about 10 mm. No significant differences were determined.

When the cracks were sealed, the following procedure was followed:

• a) the cracks to be filled are marked
• b) the construction site is set up
• c) the cracks are, if need be, cleaned and dried using a propane thawing apparatus
• d) the mortar according to the invention is poured by hand into the cracks, at an external temperature of +5° C. to +35° C., or applied with a spatula, and
• e) the sealing compound is reworked, in particular spread with a spatula. The reworking proceeds immediately after application of the mortar.

The sealing compound is cured approximately 33 h after processing. The filled crossties can, however, be used for traffic immediately after completion of the remediation.

Claims

1. A method for sealing cracks in concrete crossties of a railway track, in particular in concrete crossties of a ballastless railway track, wherein the cracks have a width of equal to or less than 1 mm, characterized in that, for the sealing, a mixture of an epoxy resin binder with quartz sand is used, wherein the quartz sand has a grain size from 0.1 mm to 1 mm.

2. The method as claimed in claim 1, wherein a grain size from 0.2 mm to 0.7 mm, in particular from 0.4 mm to 0.7 mm, is used.

3. The method as claimed in claim 1, wherein epoxy resin binder and quartz sand are used in a mixing ratio of 1:1 weight percent.

4. The method as claimed in claim 1, wherein, as epoxy resin binder, a 2-component agent is used.

5. The method as claimed in claim 1, wherein, as epoxy resin binder, Icosit® is used.

6. The method as claimed in claim 5, wherein, as epoxy resin binder, Icosit® KC 220/60 TX is used.

7. The method as claimed in claim 1, wherein a crack that is to be sealed is dried before it is filled with the mixture.

8. The method as claimed in claim 7, wherein a propane thawing apparatus is used for the drying.

9. A sealing agent for use in the method as claimed in claim 1, characterized in that the sealing agent consists of a mixture of an epoxy resin binder with quartz sand, wherein the quartz sand has a grain size from 0.1 mm to 1 mm.

10. The sealing agent as claimed in claim 9, wherein the quartz sand has a grain size from 0.2 mm to 0.7 mm, in particular from 0.4 mm to 0.7 mm.

11. The sealing agent as claimed in claim 1, wherein epoxy resin binder and quartz sand are present in a mixing ratio of 1:1 weight percent.

12. The sealing agent as claimed in claim 1, wherein the epoxy resin binder is a 2-component agent.

13. The sealing agent as claimed in claim 1, wherein the epoxy resin binder is Icosit®.

14. The sealing agent as claimed in claim 13, wherein the epoxy resin binder is Icosit® KC 220/60 TX.