Patent Application
20130147075
The present invention relates to a method and a sealing agent for closing cracks in concrete crossties.
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.
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.
Icosit® KC 220/60 TX was mixed with quartz sand of the following grain sizes:
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:
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10405133.9 | Jul 2010 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CH2011/000156 | 6/30/2011 | WO | 00 | 2/20/2013 |
