RPF NOVEMBER 2005REPORT BACK ON TREMTI ‘05

Steph Bredenhann

24 – 26 October 2005Paris, France

Main Topics

1. Fundamental aspects2. Geology and weather3. Soil treatment4. Pavement recycling5. Materials recycling6. Technology: Equipment & processes7. Codification: Guides & standards8. Complementary aspects for specific needs9. Investors’ point of view

Fundamental Aspects

Constituents and interactions – Micro-macro approach– Properties and evolution of treated materials– Formulation of new products– New applications

Behaviour of treated materials (performance and durability)

– Mechanical behaviour– Soil treatment durability issues

Geology and Weather

Geology: Sulphatic, organic and other elements– Heave and Ettringite (Ca,Al) & Thaumasite (Ca,Si)– Ground granulated blast furnace slag (GGBS)– Increased mellowing time with lime treatment– Effect of Mica

Weather conditions– Freeze-thaw (addition of rubber compounds)– Coarse vs fine-grained soils– Temperature– Water– Cracking– Stabilisation increase durability

Soil Treatment

Treatment for embankments & capping layers Soil treatment road foundations Cold in-place treatment Savings and environmental benefits Techniques to mitigate cracking

– Pre-cutting vs Pre-cracking– Pre-cracking performs the best– Recovery of strength after pre-cracking

Pavement Recycling

Cold in-place treatment Retread process Inlays Savings and environmental benefits Laboratory investigations important Mitigation of cracking Workability period (< 2h)!!!

SA EXPERIENCE:Conditioning Time

N01-12 COLESBERG TO ORANGE RIVERINFLUENCE OF COMPACTION DELAY ON ITS

2% CEM II 32,5 A/L

0

50

100

150

200

250

300

350

400

0 1 2 3 4 5 6 7 8

TIME (h)

ITS

(kP

a)

Materials Recycling

Recycling material from trenches RAP in cement stabilised material Marine/dredge sludge Recycle old embankments Soil cement Lime stabilisation Scalping materials from quarries Political and regulatory issues

Technology: Equipment/ Processes

Soils preparation Spreading of binder

– Dry processes– Wet processes

In-situ treatment vs plant-mixed Valorisation of heterogeneous materials

Codification: Guides & Standards

Need for more documentation Need more research

– Mechanical strength– Modulus– Fatigue

Investors’ Point of View

Soil treatment high speed railway Italy Urban applications in France Motorways program Spain Pavement recycling in Marocco Strategy of regional application in France