Method for preparing a hydraulic composition
In one embodiment, the present invention includes a method for preparing a hydraulic composition including sand in which clay is present, the method including adding to the sand and clay a cationic polymer having a density of cationic charges which is greater than 0.5 meq/g and an intrinsic viscosity which is less than 1 dl/g, said cationic polymer being present in an amount of from 2-20% by weight based on the amount of clay present, said clay present in an amount of from 0.5-5% by weight of the sand present, and water.
1. A method for preparing a hydraulic composition including sand in which clay is present, the method comprising adding to the sand and clay a cationic polymer having a density of cationic charges which is greater than 0.5 meq/g and an intrinsic viscosity which is less than 1 dl/g, said cationic polymer being present in an amount of from 2-20% by weight based on the amount of clay present, said clay present in an amount of from 0.5-5% by weight of the sand present, and water.
2. The method of claim 1 , wherein water and the cationic polymer form an aqueous solution and are added to the sand and clay simultaneously.
3. The method of claim 2 , wherein the aqueous solution is added to the sand and clay by spraying.
4. The method of claim 1 , wherein the cationic polymer is added to the sand and clay prior to the addition of water.
5. The method of claim 4 , wherein prior to the addition of water, the sand and clay has a moisture content of less than 10 percent by weight of the sand and clay.
6. The method of claim 4 , wherein the cationic polymer is combined with the sand and clay in a quarry.
7. The method of claim 1 , wherein the cationic polymer is combined with the sand and clay in a concrete mixing plant.
8. The method of claim 1 , wherein the hydraulic composition is a cement, a concrete or a mortar.
9. The method of claim 1 , wherein the water is added in an amount of about 11.5% by weight of the hydraulic composition.
10. The method of claim 1 , wherein the water is added in an amount of about 15% by weight of the hydraulic composition.
11. The method of claim 1 , wherein the cationic polymer has a density of cationic charges greater than 2 meq/g.
12. The method of claim 1 , wherein the polymer has an intrinsic viscosity less than 0.6 dl/g.
13. The method of claim 1 , wherein the cationic polymer is linear.
14. The method of claim 1 , wherein the cationic polymer contains cationic groups in the main chain.
15. The method of claim 1 , wherein the polymer is prepared by means of condensation of epichlorohydrin with a dialkylamine.
16. The method of claim 15 , wherein the dialkylamine is dimethylamine.
17. The method of claim 1 , wherein the cationic polymer comprises groups of quaternary amines.
18. The method of claim 1 , wherein said cationic polymer is present in an amount from 5-10% by weight based on the amount of clay present in the mixture of clays in sands.