Where are iron silicate products used?

Our products play a major role in modern hydraulic engineering. There, they secure embankments and beds of rivers, canals and harbor basins against current and wave loads. They protect harbor piers and break the waves heading for the coast. Furthermore, our iron-silicate products are used in track construction, as cement and concrete aggregates, and in corrosion protection.

Embankment construction

Due to their excellent physical properties, our armorstones are predestined for use in embankment construction. The high bulk density under buoyancy, for example, offers great advantages over other building materials. Furthermore, the cubic grain shape, the surface roughness and the grain distribution play an important role for the construction method and positional stability on embankments.


More details on the application for embankment construction
Clear advantages
  • For new construction or rehabilitation: Here, lower surface layers are possible, which at the same time can result in considerable savings in soil removal.
  • For the maintenance of waterways: Here, the use of smaller stones brings clear advantages in terms of interlocking, positional stability and adaptation to the existing revetment.
Areas of application
  • Revetments on embankments, groynes and guide dams
  • Erosion-resistant revetments on exposed underwater embankments
  • Foot protection
  • Flashover protection on flood protection structures

It is worthwhile for every planner to compare armourstones made of iron-silicate stone and other types of stone for all parameters in the concrete design case in order to make a decision.

Example calculation for material requirements

The use of iron-silicate hydraulic construction stone results in considerable weight differences compared to other rock types of medium bulk density.

Bulk density
  • Iron-silicate rock: ~ 3.65 t/m
  • rock aggregate: ~ 2.65 t/m
  • Difference: approx. 40%

When backfilling with iron-silicate armor stone, the installation results in a difference under buoyancy of approx. 60%.

This technical advantage allows either lower installation thicknesses or, for a given installation thickness, a higher weight per unit area under buoyancy. In individual cases, savings in soil removal must also be taken into account.

In principle, when using iron-silicate stone, the planning engineer can design the structure with smaller stone types and lower paving thicknesses.

Slope gradients of 1:2 to 1:1.5 are possible. As a rule, installation is possible as loose fill and without grouting.


Ballast and bottom protection

Increasingly large ships and current loads cause erosion at the bottom of harbors, canals, lock areas and rivers, which can be remedied or even avoided by using iron-silicate stone.

By optimally mixing individual fractions of iron-silicate stone, a hydraulic construction stone mixture is produced for these applications.

Further details on the application for surcharge and base protection
Application area

Bottom protection to prevent scouring

  • in front of quays
  • in ferry niches
  • in lock areas
  • in rivers and canals
  • on bridge piers
Surcharge to increase the earth resistance
  • in front of bank edgings and wharves
  • in trough sections
  • in tunnel construction                                                                                                                                                                                                                                                                  Slope stabilization/erosion stabilization of covers

Since 1975, large quantities of armourstone mix made of iron silicate have been successfully used for various problem areas throughout northern Germany.

Once installed, this armourstone mixture performs its task for decades and defies increasingly high stresses. The need for reworking or rehabilitation is thus reduced to an absolute minimum.

Technical data

Composition Armourstone mixture:

  • Crushed sand 0/5 mm
  • Chippings 5/22 mm
  • Crushed stone 22/45 mm
  • Armourstone CP45/125

The exact composition can be implemented individually according to planning specifications.

  • Bulk density ~ 3,65 t/m
  • Bulk density dry ~ 2,30 t/m
  • Bulk density under buoyancy ~ 1,67 t/
  • Low void ratio aggregate
  • Very high bulk density under buoyancy
  • Grain graded, filter effective material
  • High internal friction angle
  • Flexible underwater rock layer

Simple and cost-effective single-layer installation
Simple and inexpensive rework
Can be rammed through
Unproblematic economic removal
Bottom securing

Road construction

Iron-silicate aggregates can be used as frost protection and ballast base courses as well as paving bedding throughout road construction.

Further details on the application in road construction
Special advantages
  • Very good load bearing capacity
  • Very good frost resistance
  • Good water permeability

Our aggregates meet the requirements of TL Gestein-StB 04 / TL SoB-StB 04 and are certified and quality-controlled accordingly by:

  • Factory production control (WPK)
  • External quality monitoring
Further fields of application
Heavy Concrete

Special advantages result from the use of heavy concrete with iron-silicate stone as aggregate. Areas of application for this are, for example, heavy-load bases for buoyancy control, locks, trough sections, etc.

Drainage and landfill construction

Due to its material-specific properties, our iron-silicate granules are ideally suited for drainage and landfill construction.

Corrosion protection

From the iron-silicate granulate, the company Brümmer Strahlmittel GmbH & Co. KG produces the mineral abrasive NAstra® according to DIN/EN/ISO 11126-3. This product is used for all applications in corrosion protection.