1. daniel.puiatti@lhoist.com Lime Stabilization Daniel Puiatti March 2O th, 2006 1.Lime : Definitions – Properties – Applications 2.Treatment Techniques in Europe 3.Tremti 2005 : Introduction 4.Tremti 2005 : Lime Treatment Feed Back

2. March 21 st, 2006 daniel.puiatti@lhoist.com2 Daniel PUIATTI 59 – French - Civil Engineer (1970) LHOIST Group (Lime producer) – Since 1989 Corporate Marketing Director - Civil Engineering RAZEL (Contractor : Roadworks & Earthworks) - 6 years LCPC (Central Lab. of Roads & Bridges) Nantes - 2 years LRPC (Regional Lab. of Roads & Bridges) Rouen - 8 years COLAS (Contractor : Roadworks) - 2 years

3. daniel.puiatti@lhoist.com Lime Definitions - Properties - Applications Daniel Puiatti March 21 st, 2006

4. daniel.puiatti@lhoist.com4 Synopsis ♦Part I: Definitions ♦Part II: Lime Properties ♦Part III: Lime Applications

5. March 21 st, 2006 daniel.puiatti@lhoist.com5 Calcium Air lime ♦Produced by calcination of limestone (T > 900°C) ♦Slowly hardens in the air by combination with CO 2 Hydraulic lime ♦Produced by calcination of clayey or siliceous limestone (T > 1000°C) ♦Hardens with water Definitions (1)

6. March 21 st, 2006 daniel.puiatti@lhoist.com6 CaO Calcium oxide Quicklime Ca(OH) 2 Calcium hydroxide Hydrated Lime CaCO 3 Calcium carbonate Limestone Definitions (2) : Calcium air lime cycle T > 900°C + Water + CO 2

7. March 21 st, 2006 daniel.puiatti@lhoist.com7 Synopsis ♦Part I: Definitions ♦Part II: Lime Properties ♦Part III: Lime Applications

8. March 21 st, 2006 daniel.puiatti@lhoist.com8 Lime Properties (1) ♦Hydrate : Chemical Base Ca ++ + 2OH - ● Ca ++ ● pH ♦Quicklime hydration CaO + H 2 O => Ca(OH) 2 + heat

9. March 21 st, 2006 daniel.puiatti@lhoist.com9 Lime Properties (2) ♦Hydrate : Chemical Base ● Multi-Functional Modifying Agent  Clayey materials  Aggregates  Bitumen ● Chemical reagent for « cementitious » reaction  Clay  Fly Ash  Limestone  Blast Furnace Slag ♦Quicklime hydration ● Moisture reduction of wet soils or materials

10. March 21 st, 2006 daniel.puiatti@lhoist.com10 Example : Lime action on wet clayey soils Short term (1) ♦Immediate reduction of the water content  Improvement of the bearing capacity. Immediate Improvement of the Workability ♦Immediate reduction of the clay activity due to the flocculation (1% CaO may reduce water content by 1 to 5% by mass of wet soils depending on weather and mixing conditions) Wn CBR PI

11. March 21 st, 2006 daniel.puiatti@lhoist.com11 Before Lime Treatment After Lime Treatment Immediate Improvement of the Workability ! Example : Lime action on wet clayey soils Short term (2)

12. March 21 st, 2006 daniel.puiatti@lhoist.com12 With lime Example : Lime action on wet clayey soils Middle to long term (1) ♦Gradual hardening of the mixture thanks to bonds formed during the pozzolanic reaction between clay & lime Without lime Better Resistance to Traffic, Water, Frost

13. March 21 st, 2006 daniel.puiatti@lhoist.com13 Ca ++ + SiO 2 + H 2 O = Hydrated Calcium Silicate (CSH) Ca ++ + Al 2 O 3 + H 2 O = Hydrated Calcium Aluminate (CAH) Water + high pH Ca ++ + = Clay (SiO 2 + Al 2 O 3 ) CSH CAH Pozzolanic reactions with clayey soils Example : Lime action on wet clayey soils Middle to long term (2)

14. March 21 st, 2006 daniel.puiatti@lhoist.com14 ● Reduction of the swelling potential of the clay ● Reduction of the risk of settlements ● Increase of the cohesion ● Resistance to water and frost ● Increase of the mechanical performance (Rc, Rt, E) = f(type of soil, temperature, time) Benefit of Lime action on wet clayey soils (1)

15. March 21 st, 2006 daniel.puiatti@lhoist.com15 Evolution of shear strength (Lime treated silt : PI = 14 ; CaO = 2%) Benefit of Lime action on wet clayey soils (2)

16. March 21 st, 2006 daniel.puiatti@lhoist.com16 Synopsis ♦Part I: Definitions ♦Part II: Lime Properties ♦Part III: Lime Applications

17. March 21 st, 2006 daniel.puiatti@lhoist.com17 Roman Roads (3 rd Cent. BC to 4th Cent.) Lime in structures is a long story !

18. March 21 st, 2006 daniel.puiatti@lhoist.com18 Lime Applications ♦Soil Treatment ● Soil improvement (embankment) : milled quicklime ● Soil stabilization (capping layer, platform) : milled quicklime and slurry ♦Hot Mix Asphalt (HMA) – Cold Mix Asphalt (CMA) ● Adhesion improvement between acidic aggregates & bitumen ● Bitumen stiffening and age hardening reduction ♦Reagent mixed with industrial by-products for the production of hydraulic binders ● Fly ash ● Blast furnace slag ♦Component of specific mortars ● Tunnels ● Soil injections

19. March 21 st, 2006 daniel.puiatti@lhoist.com19 Lime Applications : Soil Treatment Stabilization (Platforms) Improvement (Earthworks) Soil Treatment before limeafter lime Earthworks Roadworks Capping layer Embankment Pavement