ULTRA-HIGH PERFORMANCE CONCRETES HAVING A LOW CEMENT CONTENT

Abstract

A hydraulic binder includes, as percentage by mass: from 17 to 55% of a Portland cement, the particles of which have a D50 of from 2m to 11 m; at least 5% of silica fume; from 36 to 70% of a mineral addition A1, the particles of which have a D50 of from 15 to 150 m; the sum of these percentages being from 80 to 100%; the sum of the percentages of cement and of silica fume being greater than 28%; the mineral addition A1 being selected from slags, pozzolanic additions or siliceous additions such as quartz, silico-calcareous mineral additions, calcareous additions such as calcium carbonate or mixtures thereof.

Claims

1. A hydraulic binder comprising as percentage by mass: from 17 to 55% of a Portland cement the particles of which have a D50 comprised from 2 m to 11 m; at least 5% of silica fume; from 36 to 70% of a mineral addition Al the particles of which have a D50 comprised from 15 to 150 m; a sum of these percentages of cement, silica fume and the mineral addition A1 being comprised from 80 to 100%; a sum of the percentages of cement and silica fume being greater than 28%; the mineral addition A1 being selected from among slags, pozzolanic additions or siliceous additions, siliceous limestone mineral additions, limestone additions or mixtures thereof.

2. The hydraulic binder according to claim 1, wherein the cement is a CEM I cement.

3. The hydraulic binder according to claim 1, further comprising calcium sulfate.

4. The hydraulic binder according to claim 1, wherein the cement particles have a D90 comprised from 8 m to 25 m.

5. A mixture comprising as percentage by volume, at least 45% of the hydraulic binder according to claim 1 and at least 30% of sand, a sum of these percentages of the hydraulic binder and the sand being comprised from 95 to 100%.

6. The mixture according to claim 5, further comprising a sand the particles of which have a D10 comprised from 100 um to 1 mm and a D50 comprised from 200 m to 3 mm and a D90 from 300 m to 5 mm.

7. The mixture according to claim 5, wherein the sand is a siliceous sand, a calcined bauxite sand, a siliceous limestone sand, a limestone sand or mixtures thereof.

8. A hydraulic composition comprising in a volume of 1 m.sup.3 excluding entrained air and excluding fibers: from 155 to 205 liters of water; at least 770 liters of mixture according to claim 5; the sum of the volumes of the water and the mixture being comprised from 950 to 1,000 liters.

9. The hydraulic composition according to claim 8 comprising an antifoaming agent.

10. The hydraulic composition according to claim 8, further comprising mineral, organic or metal fibers, or a mixture thereof.

11. A shaped object for the field of building comprising the hydraulic binder according to claim 1.

12. The hydraulic binder according to claim 1, wherein the siliceous additions include quartz.

13. The hydraulic binder according to claim 1, wherein the limestone additions include calcium carbonate.

14. A shaped object for the field of building comprising the mixture according to claim 5.

Description

EXAMPLES

[0121] The present invention is described by the examples A, B, C, D, E, F, G, H which follow, which are non-limiting.

TABLE-US-00001 Raw materials: Cement 52.5N PMES Le Teil Lafarge France Millisil C6 Sibelco, France Silica fume, MST02 Le Pontet SEPR, France Anhydrite, Micro A Maxit, France Sand, BE01 Sibelco, France Superplasticizer F2 Chryso, France

[0122] The cement was prepared by milling and separating Portland cement CEM I, 52.5N PMES, from Lafarge Le Teil cement works. This milling was carried out by using an air jet milling machine associated with a very high efficiency separator. The ground cement obtained had a D10 of 1.7 m, a D50 of 5.3 m, and a D90 of 10.6 m. The Blaine specific surface area was 6,950cm.sup.2/g and the BET specific surface area was 1.65m.sup.2/g.

[0123] Le Millisil C6 is a siliceous filler (quartz) from Sibelco. It corresponds to the A1 addition. It has a D10 of 2.9 m, a D50 of 28.9 m, and a D90 of 95.6 m.

[0124] The silica fume MST 02 from SEPR, is characterized by a BET specific surface area of 12 m.sup.2/g.

[0125] Micro A anhydrite is micronized anhydrous calcium sulfate supplied by Maxit. It has a D10 of 1.6 m, D50 of 12.3 m and D90 of 17.0 m.

[0126] BE01 sand is siliceous sand supplied by Sibelco. It has a D10 of about 210 m, and a D50 of about 310 m, a D90 of about 400 m.

[0127] The superplasticizer F2 is a new generation superplasticizer containing a modified polycarboxylate.

[0128] Equipment: [0129] kneader-mixer RAYNERI R601, which was provided by VMI with a tank of 10 liters. This kneader exerts a planetary rotary movement; [0130] cylindrical cardboard molds with a diameter of 7 cm and a height of 14 cm; [0131] a weathering chamber with 95-100% relative hygrometry and 90 C. +/1 C. provided by Verre Labo Mula; [0132] a humid chamber with 95-100% relative hygrometry and 20 +/1 C.

[0133] Procedure for Preparing the Hydraulic Composition According to the Invention:

[0134] The concrete (hydraulic composition) was manufactured according to the procedure described hereafter: [0135] 1) introduction of the dry materials (sand, A1, cement, calcium sulfate and silica fume) in the bowl of the Rayneri kneader; [0136] 2) kneading for 3 minutes at the rate of 15 revolutions per minute, for homogenizing the dry materials; [0137] 3) introduction of the mixing water and one half of the super-plasticizer over 30 seconds, at a rotation speed of 35 revolutions per minute; [0138] 4) kneading for 4 minutes and 30 seconds at a speed of 35 revolutions per minute; [0139] 5) introduction of the other half of superplasticizer over 30 seconds at a rotation speed of 50 revolutions per minute; [0140] 6) kneading for 2 minutes and 30 seconds at speed of 50 revolutions per minute; [0141] 7) stopping the kneader.

[0142] A fresh concrete was obtained. The concrete was cast into cylindrical molds. The obtained molded specimens are hermetically closed and are pending for 24 hours at 20 C. Next, the specimens are removed from the mold and are either placed: [0143] in a humid chamber for 28 days at 20 C. and 100% of relative humidity; or [0144] in a humid chamber for 7 days at 20 C. and 100% relative humidity, and then in a weathering chamber for 48h at 90 C. and 100% relative humidity (heat treatment).

[0145] The mechanical strengths were then measured. [0146] Hydraulic binders according to the invention, in % by mass:

TABLE-US-00002 % Calcium % Cement % A1 % Silica Fume sulfate A 18.2% 40.7% 40.3% 0.8% B 42.0% 37.5% 18.6% 1.9% C 17.7% 61.9% 19.6% 0.8% D 48.7% 43.1% 6.0% 2.2% E 25.6% 66.9% 6.3% 1.2% F 26.3% 46.6% 25.9% 1.2% G 33.9% 52.1% 12.5% 1.5% H 34.0% 48.0% 16.5% 1.5% [0147] Composition of the mixtures according to the invention in volume %:

TABLE-US-00003 % Hydrolic binder % Sand A 50.8% 49.2% B 51.0% 49.0% C 50.8% 49.2% D 51.1% 48.9% E 50.8% 49.2% F 50.8% 49.2% G 50.9% 49.1% H 50.9% 49.1% [0148] Hydraulic compositions according to the invention in liters per 1 m.sup.3 of concrete:

[0149] The hydraulic compositions according to the invention are described below in liters /m.sup.3 of concrete excluding entrained air and excluding fibers.

TABLE-US-00004 Mixture Admixture Added Water Total Water A 828.9 18.7 152.4 166.8 B 821.6 12.2 166.2 175.5 C 833.0 12.2 154.8 164.2 D 804.1 10.3 185.6 193.5 E 808.2 9.4 182.4 189.6 F 832.0 13.1 154.9 165.0 G 832.0 11.2 156.8 165.5 H 829.8 11.7 158.5 167.5 [0150] Performance of the hydraulic composition:

[0151] Mechanical compressive strengths were measured on a cylinder of diameter 70 mm and height of 140 mm. The results are expressed as MPa.

TABLE-US-00005 CS at CS Heat 28 days/20 C. treatment A 135.6 199.4 B 187.2 239.1 C 134.8 196.2 D 164.9 202.4 E 128.9 169.1 F 154.9 219 G 181.4 225.2 H 176 235.7