Application
Light fill for abutment backfill

Partner company / customer
Autobahndirektion Südbayern

company
Max Streicher, Altenmarkt

Quantity   5,000 m³

Product specification
TECHNOpor glass foam granulate STRASSENBAU

Description

Widening of the motorway A8 Munich – Salzburg from four lanes
without hard shoulder to six lanes with hard shoulder also
necessitated the construction of a new bridge for the intersecting
railroad traffic on the route Rosenheim – Salzburg.

Due to the low load-bearing capacity of the ground in the area
in question, the track bed construction at both ends of the bridge
was to be carried out using lightweight building materials to minimize
subsidence in the area immediately surrounding the pillar foundation
bridge and thus reduce the maintenance and upkeep in the future.
For support, one drag plate was to protrude into the compacted glass
foam fill on each side.

The decision in favour of TECHNOpor glass foam granulate was made
for the following reasons:

·         Glass foam granulate is a fill made up of angular shaped grains and 
          can, unlike expanded clay, be easily built up to layers of 80 cm in height.

·         Independent of layer thickness high load levels can be supported.

·         TECHNOpor glass foam granulate is lighter than expanded clay by factor 2.

·         In contrast to expanded clay, which displays a water absorption capacity
          of up to 50% (mass-related), that of glass foam is under 10% (mass-related).

·         As a fill, glass foam granulate provides drainage, thus preventing a 
          “softening” of the track bed structure in case of water ingress.

Execution

TECHNOpor glass foam granulate was installed in layers, distributed
with a bulldozer and compacted with a roller. In each installed 50 cm
thick layer the required modulus of elasticity was proven.
The glass foam granulate was protected from the soil or the layer structure
by separation fleece on all sides. Parallel to the rising installation height
of the glass foam granulate, a protective layer of filling material (excavated soil)
was built up on the flanks and compacted to achieve the lateral tension
of the glass foam fill.
At the halfway point the drag plates were installed and then the glass foam
granulate was again built up in layers to the final installation height of 3.5 m.
The final layer of glass foam material, which was covered by Geo-fleece,
received a 1.25 m thick protective layer of gravel.
The construction of the layers continued on this base. 

Conclusion

The construction firm was surprised at how easy and quick the installation
of TECHNOpor glass foam was. The material as well as customer and
consulting service of TECHNOpor appealed to the customer.
The delivery of the glass foam just in time and according to the
predetermined time schedule – with all the particularities such a construction
project with regular traffic flow entails – provided for a smooth progress
and the customer’s complete satisfaction.