Installation Guideline
Under Ballast Mats with 2 elastic layers

1. General Description
Getzner Under Ballast Mats (UBM) passed all serviceability
tests in accordance with the latest standard.
A few rules must be followed during installation in orderto enable hassle-free installation and the highest possibleperformance.
Attention: Please note that in case of bonding the underballast mats with Diisocyanate containing bonding
agents, staff needs to be trained and certified conform
EU legislation 2020/1149. More information you can findvia link https://safeusediisocyanates.eu/.

2. Transport and StorageGetzner UBM corresponding to the type, their thickness
and weight are delivered in rolls and therefore are very
easy to handle. The side of the mats facing the ballast is
protected by a geotextile. This geotextile has practicallytwo functions – as a protective layer against ballast grain
penetration of the spring layer as well as a load distribution
layer throughout the load bearing area.
The UBM are delivered in a width of 1500 mm. The lengthof the mats usually meets the width of the track bed andis clarified with the client in advance. Getzner UBM for thehighest demands on vibration mitigation are delivered
with 2 elastic layers and the upper layer is equipped withthe geotextile to protect the high elastic layers from theballast. The same principle applies to Getzner sidewall
mats usually mounted and glued on slanting and vertical/perpendicular surfaces. The standard length of the Getzner
sidewall mats is 1500 mm, whilst the width depends on theballast depth or banking and needs coordination with theclient in advance.
To ensure fast installation Getzner ballast mats have to
be kept dry and clean. The rolls must be stored upright.
The adhesive has to be stored frost-free. Ballast mats
have to be protected against strong ultraviolet radiation.
Therefore the continuous direct exposure to sunlight hasto be avoided.

Protection layer (geotextile) always facing the ballast (upwards)

Elastic layer 1

Elastic layer 2

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Installation Guideline
Under Ballast Mats with 2 elastic layers

3. Installation
In general, the following applies: The installation iscarried out according to the installation guideline
respectively installation instructions. The guidelines ofthe railway operator must be followed.

3.1 Preparation of the substructure
The substructure has to be free of dust, grease, frost-freeand dry as well as free of depressions and sharp-edged
elevations. Loose objects, e. g. grit, have to be removed.

3.2 General procedure for multi-layer design
Multi-layer UBM can generally be handled the same assingle-layer mats. Each layer should be installed and glued
separately. The detailed procedure is described in chapter
3.4 and 3.5. To ensure optimum functionality, the lower
and upper layer are installed with an offset of minimum
100 mm. For practical reasons, an offset of 1/2 mat width(approx. 75 cm) is recommended.

3.3 Placing of UBM
The first layer of UBM (without geotextile) should be placedfollowed by the second layer (with geotextile).
The geotextile protection layer of the mats represents
the surface. According to the installation plan, the UBM
are unrolled transversely to the track axis in order toavoid joints under or parallel to the rail. When exposed
to extreme temperatures and differences in temperature,
the UBM should at first be unrolled, placed in position andleft to settle for a few hours before gluing. This allows thematerial to recover from compression. Changes in lengthof the mats due to temperature are a physical process
and are completely reversible. If necessary, these can becompensated by either pulling or cutting.
In the case of very tight curves (and thus large angulardeviations), the mats can be adjusted on site by cutting thelong side in a wedge shape.

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Installation Guideline
Under Ballast Mats with 2 elastic layers

3.4 Adhesion to the substructure
To avoid displacement during ballasting, the mats have to beglued to the subtructure – if required by the infrastructure
operator in accordance with the installation instructions.
Ideally a two-component solvent-free polyurethane
adhesive (approx. 0.4 kg/m2 USM) is used. A suitableadhesive can be supplied directly by Getzner Werkstoffe.
The surface temperature should be at least +5 °C at thetime of gluing.
The pot life depends on the amount and temperature of
the mixture (adhesive + hardener). Please refer to themanufacturer's data sheet regarding the processingtemperature and curing time of the adhesive.
The adhesive is applied in dots in order to enable proper
drainage underneath the UBM. Firstly one half of the UBM
is folded from one sidewall to the other one in order toapply the glue. Immediately afterwards, the mat is foldedback again. After this half is glued, the same steps arerepeated for the other half.

3.5 Connection of UBM / sealing of joints
The mats are connected with approx. 9 cm wide geotextile
strips, which are supplied by Getzner Werkstoffe. Thesestrips are either fixed with a hot air welding machine(Getzner Weld-Jet) or glued with UBM adhesive. Thus, thebutt joints are covered completely.
Please refer to the operating instructions for the Getzner
Weld-Jet.
To illustrate this, the geotextile strips on the left arecoloured in orange.
It must be ensured that after completing this section of
the installation the sealed mat joints are visually checkedagain.

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Installation Guideline
Under Ballast Mats with 2 elastic layers

3.6 Installation of side mats
The side mats are fully glued to the vertical parts of thestructure. A two-component polyurethane adhesive or atwo-component bitumen compound (solvent-free, cementbound) is recommended. The adhesive requirement isapprox. 1.0 kg/m2 side mat.
Butt joints of side mats are not sealed with geotextile strips.
Optionally, the side mats can be fastened with a Z-profile.
For applications on the open track, due to fluctuations in theambient temperature or solar radiation, a distance of approx.
33 cm between the fastening points of the Z-profiles should
be considered. For applications with constant ambient
temperature and without direct sunlight, such as in tunnels,a correspondingly larger distance between the fastening
points can be considered (e. g. one fastening point per
linear metre).

3.7 Supply of ballast
Ballasting should be carried out as soon as possible after
welding the butt joints and attaching the side mats (at theend of the shift at the latest).
Provided they are glued to the substructure and theadhesive has cured, Getzner UBM may be driven over at
walking speed by rubber-tyred vehicles. Construction
machines with crawlers are not permitted.
Sudden breaking, acceleration and strong steering must beavoided.

3.8 Continuation of works
After the UBM is consistently covered with at least
20 cm of ballast, all further superstructure work can be
carried out - even using heavy machinery.

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Under Ballast Mats with 2 elastic layers

4. Recycling

5. Disclaimer

Unused UBM or pieces thereof (off-cuts) can bedisposed of for recycling via standard plastic waste
containers.

This guideline only serves to support the customeror his authorised specialist in the installation ofGetzner UBM. Getzner Werkstoffe draws the attention
to known demands and problems. This guideline wascompiled with the utmost care based on Getzner’s
current knowledge.
Due to the large number of different construction
designs and requirements, Getzner Werkstoffe accepts
no liability for the completeness of the installation
guideline. In particular, Getzner Werkstoffe is not
responsible for the proper installation of Getzner UBM
and the resulting negative effects on the condition/ quality of Getzner UBM or its performance. It is
recommended that the installation is carried out bya specialist.
All other rights are reserved! Sharing withunauthorised third parties is expressly prohibited.

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