Ciments Francais

Emmanuel Moudilou

Bruno Le Rolland

Cyril Guerandel

Stephanie Delair

Pierre Cassat

Stéphanie Delair

A hydraulic binder based on a sulfoaluminate clinker including the mineralogical phases ye'elimite CA$, mayenite CA, free lime CaO, and optionally belite C2S, characterized in that, in the clinker, the mineralogical phases are 20% to 50% by weight of ye'elimite C4A3$ phase, 5% to 80% by weight of mayenite CAphase, and 1% to 5% by weight of free lime CaO, the weight ratio between the mayenite CAand ye'elimite CA$ phases being between 0.1 and 10. The binder can be used to treat polluted soils, in particular soils with a leachable fraction greater than 0.4% that contains predominantly anions and/or heavy metal cations by mixing the soil with the hydraulic binder, in soil/binder weight proportions of between 1 and 40 parts of binder for 100 parts of soil. It makes it possible to stabilize soils which are polluted or to stabilize soils before dumping.

Sulfoaluminate clinker based hydraulic binder and use thereof in a process for treating polluted soils

A process for treating polluted soils, in particular soils with a leachable fraction greater than 0.4%, wherein the leachable fraction contains predominantly anions, in particular sulfate ions, and/or heavy metals, includes mixing the soil with a sulfoaluminate-clinker-based hydraulic binder, in soil/binder weight proportions of between 1 and 40 parts of binder per 100 parts of soil, the sulfoaluminate clinker containing more than 50% by weight of ye'elimite CAS phase, less than 15% by weight of belite C2S phase, and from 1% to 5% by weight of free lime CaO. The process is used for stabilizing soils in situ or before dumping, soils polluted in particular with sulfate anions and/or heavy metal cations.

Process for treating polluted soils by means of a sulfoaluminate clinker based hydraulic binder and use thereof for stabilizing polluted soils

A method of treating marine or river dredging sediments, especially harbour zone sediments, whose free water content is between 40% and 80% by weight, for the purpose of obtaining a solid material which is easy to handle, includes the following successive steps: mixing the sediments with a treatment composition including a sulphoaluminate binder and at least one other component selected from a sulphate source and a catalyst of the hydration reactions of the sulphoaluminate binder; a step of setting of the mixture, leading to a compact mixture having a free water content of less than 20% by weight; then fractionating the compact mixture. The sediment thus treated may be incorporated into concrete or mortar formulas, which then have leachable fractions of less than 1% by weight.

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Breuilpont, France

Emmanuel Moudilou