Concrete composition
The concrete composition includes, in a mixture with water, a hydraulic binder, sand and aggregates, wherein the hydraulic binder includes a Portland cement of high reactivity, and the hydraulic binder is present in an amount of 280-340 kg per cubic meter of concrete, a shrinkage reducing admixture is present in an amount of 0-4 L per cubic meter of concrete, and water is present in an amount of 140-160 L per cubic meter of concrete.
1. A concrete composition comprising, in a mixture with water, a hydraulic binder, sand and aggregates, wherein the hydraulic binder comprises a Portland cement of high reactivity, wherein the Portland cement has a Blaine fineness of 4500-6500 cm 2 /g, characterized in that the hydraulic binder is present in an amount of 280-310 kg per cubic meter of concrete, that a shrinkage reducing admixture is present in an amount of 3-4 L per cubic meter of concrete, wherein the shrinkage reducing admixture is an organic admixture, and that water is present in an amount of 140-160 l per cubic meter of concrete.
2. A concrete composition according to claim 1 , wherein the reactivity of the hydraulic binder is selected so as to obtain a 28d compressive strength of the concrete of >52.5 MPa.
3. A concrete composition according to claim 1 , wherein the reactivity of the hydraulic binder is selected so as to obtain a 1d compressive strength of the concrete of >20 MPa.
4. A concrete composition according to claim 1 , wherein the hydraulic binder comprises a supplementary cementitious material.
5. A concrete composition according to claim 4 , wherein the supplementary cementitious material is present in an amount of 1-20 wt.-% of the hydraulic binder.
6. A concrete composition according to claim 4 , wherein the supplementary cementitious material has a Blaine fineness of 4500-6500 cm 2 /g.
7. A concrete composition according to claim 1 , further comprising an expanding agent in an amount of 0.5-3 wt. % of the hydraulic binder.
8. A concrete composition according to claim 1 , further comprising a water reducing agent.
9. A concrete composition according to claim 8 , wherein the water reducing agent comprises poly-carboxylate ether or polynaphthalene sulfonate.
10. A concrete composition according to claim 1 , wherein the concrete composition is freshly mixed and the amount of water and hydraulic binder is selected so as to reach a flow of the freshly mixed concrete at 10 min of at least 100 mm+/−10 mm.
11. A concrete composition according to claim 1 , wherein within less than 50 days after placing the concrete has a relative humidity of 80% according to ASTM F2170.
12. A concrete composition according to claim 1 , wherein the shrinkage reducing admixture is based on polypropylene glycol, polyethylene glycol and/or a glycol ether derivative, and is, optionally, in a liquid mixture with surfactants.
13. A concrete composition according to claim 4 , wherein the hydraulic binder comprises, as the supplementary cementitious material, ground granulated blast furnace slag, fly ash, pozzolans, ground limestone or mixtures thereof.
14. A concrete composition according to claim 7 , wherein the expanding agent comprises CaO.
15. A concrete composition according to claim 8 , wherein the water reducing agent, is present in an amount between 0.4 and 1 wt. % of the hydraulic binder.
16. A concrete composition according to claim 1 , wherein within less than 40 days after placing the concrete has a relative humidity of 80% according to ASTM F2170.
17. A concrete composition according to claim 1 , wherein within less than 30 days after placing the concrete has a relative humidity of 80% according to ASTM F2170.
18. A construction element comprising concrete obtained from a concrete mix composition according to claim 1 .