Modified soil stabilisation with ROADFLEX RF®

An innovative construction method to save CO2, conserve resources and improve sustainability in road construction and soil stabilisation.

What triggered us?

The road construction sector, and along with it soil construction, is one of the most resource-intensive sectors in Germany, as large quantities of raw materials are consumed. According to the Federal Statistical Office and the German Council for Sustainable Development, the road construction industry alone were responsible for 40% of CO2 emissions and 54.2% of waste in Germany by 2022. The aim must be to use limited resources as economically as possible. Furthermore, our public road network is no longer able to absorb the traffic loads due to ever-increasing axle loads. Many roads in the communities show severe damage because of the substructure were dimensioned to less and built much too weak. However, the communities have a road network that is far too large to carry out the necessary tasks. The crises in recent years have also significantly reduced the financial leeway of the communities. More and more unstable weather conditions, which lead to heavy rainfall, which cause severe damages to our roads. In order to make the roads fit for the future again, we need:

• Resource-saving construction methods

• Crack-bridging and flexible construction methods

• Resistant and hydrophobic construction methods

• CO2-saving construction methods

• Construction methods with significantly reduced production costs

History

2017

• Inital contact with Wacker Chemie AG, Burghausen, Germany

• Inital mock up´s at the Wackersite and first mock up of a unpaved road in Wurmannsquick/Germany

2020

• Initial hard shoulder compaction on Highway A93 with a provisional dosing meter device

• Design and Construction of an fully automated dosing trailer

2021

• Construction of various surface stabilizations with ROADFLEX RF® in the Bavaria North Directorate​

2024

• Start approval process as Carbonfootprint reducing contruction method with the bavarian building authority

• Runner up Innovation Award of the bavarian constrution industry, category: new product development

Modified soil stabilisation with ROADFLEX RF®?

Modified hardening based on ZTV Beton StB 07 + addition of polymer binders.

With this innovative construction method, we are moving away from a rigid system to a flexible construction method in road construction.

The result is a hydrophobic, resistant, frost-proof, very high load-bearing and flexible layer that can absorb significantly higher tensile, bending and splitting tensile forces and does not need to be notched compared to conventional consolidation.

This technology can be used to compact almost all types of soil, including very fine-grained and sometimes organic soils, which are generally no longer suitable for road construction and would have to be disposed of.

Mode of action of ROADFLEX RF®

• Polymeric binder forms bridges between cement and soil particles.

• Improving the adhesion of surfaces.

• Creation of a robust and elastic network.

• Polymer bridges form flexible compounds of particles.

• Thanks to the flexibility of the polymerhe load transfer is better cushioned and distributed

• Formation of a water-repellent (hydrophobic) layer.

• The forces exerted when loads are applied, are absorbed and distributed by the flexibility of the polymer = robust, cross-crack network.

Hard shoulder stabilisation process with ROADFLEX RF®

1. remove turf

• Using a banquet milling machine

• If necessary, replenish banquet material

• Creation of the required cross slope

2. spread binding agent

• Application of cement using a cement spreader, according to suitability test

3. speed-dependent dosing technology

• Construction output: approx. 250 m/h

• Separate dosing of the components RF800 + RF850 + water

4. milling

• Tractor with special mounted tiller

• Homogenisation of cement, water and ROADFLEX RF®

5. compaction

• Triple compaction (integrated vibratory plate on milling tractor/secondary compaction by conventional vibratory plate/rolling tractor with vibratory plate)

6. cleaning the carriageway

• High-pressure washing and vacuum sweeper

7. after-treatment of the banquet

• Spraying on a ROADFLEX RF water mixture, ®prevents drying out and binds the near-surface grain structure into the grain matrix

Hard shoulder stabilisation in the final state

• 50 cm wide

• 20 - 40 cm depth depending on requirements

Reference projects Hard shoulder stabilisation (Extract)

Hard shoulder stabilisation with ROADFLEX RF®

• BAB A93 Schwandorf 21.5 km in total Motorway Directorate Bavaria North

• Geiselhöring/ Hainsbach state building authority Passau 1.2 km

• FRG 5 National park road 500 m, Passau state building authority

• Bad Griesbach 500 m

• St Georgen im Attergau (Austria) 1.5 km

• Marchetsreut (Passau state building authority) 1 km

• Hutthurm 2 km

• BAB A93 Pfreimd 2 km Motorway Directorate Bavaria North

• Dellach im Drautal (Austria) 500 m

• BAB A6 Schwabach BW 782 b Main Donau canal bridge 500 m

• Fürth am Berg 7 km

• Salzweg Fischhauserstrasse 1800 m

• and more

use Cases, not limited to

• Reinforcement of existing embankments that are no longer load-bearing or have been washed out.

• For permanent protection of existing narrow roads in order to prevent the asphalt shoulder from being pressed down when encountering traffic.

Replacement of:

• Grass pavers

• Banquet slabs

• using hydraulically bound base course to extend the existing motorway

Process description soil stabilisation with ROADFLEX RF®

1. homogenise asphalt with frost protection layer and in-situ soil

• Homogenisation by e.g. rotary milling machine WR 200

2. create longitudinal and transverse slopes using a grader

3. compact homogenised material

• Compaction using a roller machine

4. spread binding agent

• (usually CEM II/B-M S-LL 42.5 N or mixed binder) using a binder spreader in accordance with the initial material inspection

5. refuelling water barrel with Roadflex RF800, RF850 and water

• Coordinated ratio according to the inital material inspection

6. milling ROADFLEX RF® water mixture into the homogenised soil material using a milling machine

• Milling depth between 20 and 30 cm depending on construction class

7. produce fine subgrade using a grader

8. compacting the fine subgrade using an earthmoving and pneumatic tyre roller

• Compaction of the fine subgrade

9. follow-up treatment

• Spraying on a ROADFLEX RF® water mixture,prevents drying out and binds the near-surface grain structure into the grain matrix

10. asphalting (optional)

• Curing time approx. 12-24 hours

• Possibility to reduce the asphalt superstructure

On unpaved roads, agricultural paths or bike paths, the asphalt can also be left out and the modified, stabilized base layer can be driven on directly.

Reference projects soil stabilisation (Extract)

Consolidation with ROADFLEX RF®

• Wacker Chemie Burghausen Container storage areas, access roads

• Access road to an agricultural property in Wurmannsquick

• Schönberg Gartenstrasse

• Grafenau Reismühle & Grafenau Gerstenacker

• Gunzing Irrach

• Company premises in Hauzenberg

• Municipal road Untergriesbach

• Wegscheid Kapellengartenstrasse Thurnreut

• Hutthurm Vendelsberg

• Salzweg Fischhauserstrasse

• Regensburg ferry route

• and more

use Cases, not limited to

• Road and motorway construction

• Cycle paths for Mountain Bike´s and Road Bike´s

• Bike parks

• Commercial, forestry and access roads

• Municipal and service roads

• Storage, container yards and car parks

• Consolidation in the superstructure and substructure

• Special underground solutions (e.g. for strongly rising groundwater or slope water)

• Qualified water(liquid)-impermeable soil improvement (qualified soil stabilization) in the substructure

Environmental compatibility of ROADFLEX RF®

• Eluates based on ROADFLEX RF® consolidations were analysed at the renowned Noack Institutehttps://noack-lab.com/de/

• Influence on building products, soil and groundwater was carried out and checked in accordance with DIBt www.dibt.de guidelines

• Excellent results were confirmed for ROADFLEX RF800 / RF850

• No entry of microplastics, No PFAS (per- and polyfluoroalkyl substances), No ion exchange

-> Environmental compatibility certificate is available

Advantages of ROADFLEX RF®

• Up to 50% cost savings compared to full expansion

• Conservation of natural resources

• Saving landfill deposit space

• Sustainable & complete dismantling capability

• Reduction of transport on the construction site (CO2 savings)

• Faster opening to traffic, shorter construction times

• Protection of the asphalt superstructure (at the banquet)

• Slimmer construction methods in the asphalt superstructure

• Higher load-bearing capacity, improved durability

• Reduction of noise emissions, less pollution for citizens