RPF NOVEMBER 2005 REPORT BACK ON TREMTI ‘05 Steph Bredenhann 24 – 26 October 2005 Paris, France

Main Topics 1. Fundamental aspects 2. Geology and weather 3. Soil treatment 4. Pavement recycling 5. Materials recycling 6. Technology: Equipment & processes 7. Codification: Guides & standards 8. Complementary aspects for specific needs 9. 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

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