Quick binder for self compacting concrete, use and application of same
A binder for self-compacting concrete includes, in dry weight of the-binder, 70 to 90% of Portland cement, 4 to 16% of calcium aluminate, 4 to 14% of calcium sulphate, an accelerator and a retarder, 0 to 2% of Ca(OH)2 and at least an additive with a water reducer. The calcium sulphate is in the form of anhydrite and the water reducer has at least a superplasticizer consisting of a water soluble or water dispersible organic compound, having at least an amino-di(alkylene-phosphonic) group and at least a polyoxyalkylated chain or at least one of its salts.
1. A quick binder for self-compacting concrete comprising by weight, based on the weight of the quick binder in a dry state:
70 to 90% Portland cement,
4 to 16% calcium aluminate,
4 to 14% calcium sulphate in an anhydrite form,
a setting accelerator and a setting retarder,
at least an adjuvant comprising a water reducer, wherein:
the water reducer comprises at least a superplasticizer made of a water soluble or water dispersible organic compound, comprising at least an amino-di(alkylene-phosphonic) group and at least a polyoxyalkylated chain, and wherein the superplasticizer is a compound (I) or a salt of the compound (I), said compound (I) having the formula:
wherein,
R is a hydrogen atom or a monovalent hydrocarbon group, saturated or unsaturated, comprising 1 to 18 carbon atoms and optionally, one or more heteroatoms; 50 to 100% of the R i are ethylene, 0 to 50% of the R i are similar or different to each other and represent an alkylene selected from propylene, butylene, amylene, octylene or cyclohexene, or an arylene selected from styrene or methylstyrene, the R i optionally comprising one or more heteroatoms,
Q is a hydrocarbon group having 2 to 18 carbons atoms and optionally, one or more heteroatoms,
A is an alkylene group having 1 to 3 carbon atoms,
the R i are similar or different to each other and are selected from:
*the A—PO 3 H 2 group, wherein A is an alkylene group having 1 to 3 carbon atoms,
*and the group:
—B is an alkylene group comprising 2 to 8 carbon atoms,
A is an alkylene group having 1 to 3 carbon atoms,
“n” is an number ranging from 20 to 250,
“r” is the number of [R—O(R i —O) n ] groups carried by all the R J ,
“g” is the number of [R—O(R i —O) n ] groups carried by Q,
the “r+q” sum is at the most equal to 3,
“y” is an integer equal to 1 or 2,
Q, N and the R J can form together one or more rings, said ring or rings optionally comprising one or more heteroatoms.
2. The quick binder for self-compacting concrete according to claim 1 , further comprising 2% of hydrated lime (Ca(OH) 2 .
3. The quick binder for self-compacting concrete according to claim 1 , wherein the setting accelerator comprises sodium carbonate and the setting retarder comprises citric acid.
4. The quick binder for self-compacting concrete according to claim 1 , wherein the setting retarder accounts for 0.5 to 2.5% by weight and the setting accelerator accounts for 0.5 to 2.5% by weight, based on the total weight of the quick binder.
5. The quick binder for self-compacting concrete according to claim 3 , wherein the citric acid is in a monohydrated form.
6. The quick binder for self-compacting concrete according to claim 1 , wherein the calcium sulphate in anhydrite form is an anhydrite with a hardness higher than 90%.
7. The quick binder for self-compacting concrete according to claim 6 , wherein the anhydrite comprises anhydrite II.
8. The quick binder for self-compacting concrete according to claim 1 , wherein the calcium aluminate has a minimum alumina content of 50%.
9. The quick binder according to claim 1 , wherein said superplasticizer accounts for approximately 1.5% in dry weight of the binder.
10. The quick binder for self-compacting concrete according to claim 1 , wherein a superplasticizer is the compound having the formula (II):
or one of the salts thereof.
11. The quick binder for self-compacting concrete according to claim 1 , wherein the Portland cement is a quick cement ground to a fineness higher than or equal to 4000 cm 2 /g.
12. A process for making a self-compacting concrete having a compression strength of 8 MPa minimum at 6 hours and at least 24 MPa at 24 hours, with a workability of 1 hour minimum, which comprises adding to the self-compacting concrete a binder according to claim 1 .
13. The process according to claim 12 , wherein said concrete has a compression strength of 8 MPa at 4 hours and of at least 24 MPa at 24 hours.
14. The process according to claim 12 , wherein said concrete has a workability of one and half hour to 2 hours.
15. The process according to claim 12 , wherein the concrete has a ratio of efficient water weight on dry binder ranging from 0.35 to 0.4.
16. A self-compacting concrete comprising the quick binder according to claim 1 , having a compression strength of 8 MPa minimum at 6 hours and of at least 24 MPa at 24 hours, with a workability of 1 hour minimum.
17. The self-compacting concrete according to claim 16 , wherein the concrete has a compression strength of 8 MPa at 4 hours and of at least 24 MPa at 24 hours.
18. The self-compacting concrete according to claim 16 , wherein the concrete has a workability of 1 and half hour to 2 hours.