REMEDIATION OF CROSSTIE CRACKS

ASSAINISSEMENT DE LEZARDES DANS DES TRAVERSES

English 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.

French Abstract

L'invention concerne un procédé et un produit pour injection de remplissage pour l'assainissement de lézardes dans des traverses en béton d'une voie ferrée, en particulier dans des traverses en béton d'une voie sur dalle, les lézardes présentant une largeur égale ou inférieure à 1 mm. L'invention est caractérisée en ce qu'on utilise un mélange d'un liant de résine époxyde avec du sable quartzeux, et en ce que le sable quartzeux présente une granulométrie de 0,1 mm à 1 mm.

Claims

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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 either of claims 1 and 2,
wherein epoxy resin binder and quartz sand are
used in a mixing ratio of 1:1 weight percent.
4. The method as claimed in any one of claims 1 to 3,
wherein, as epoxy resin binder, a 2-component
agent is used.
5. The method as claimed in any one of claims 1 to 4,
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 any one of claims 1 to 6,
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 any one of claims 1 to 8, characterized in that

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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 either of claims 9
and 10, 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 any one of claims
9 to 11, wherein the epoxy resin binder is a 2-
component agent.
13. The sealing agent as claimed in any one of claims
9 to 12, 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.

Description

CA 02803648 2012-12-21
WO 2012/003594 PCT/CH2O11/000156
TITLE
REMEDIATION OF CROSSTIE CRACKS
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

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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.

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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

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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.