HYDRAULIC COMPOSITION HAVING IMPROVED CARBONATION RESISTANCE

Abstract

A composition includes one hydraulic binder including at least one clinker, and at least one branched polyalkyleneimine, having a molecular weight between 400 g/mol and 1,000,000 g/mol, at a weight ratio polyalkyleneimine(s)/binder between 0.05% and 5.0%.

Claims

1-13. (canceled)

14. A composition comprising: an hydraulic binder comprising at least one clinker, and at least one branched polyalkyleneimine, having a molecular weight between 400 g/mol and 1 000 000 g/mol, at a weight ratio polyalkyleneimine(s)/binder between 0.05% and 5.0%.

15. The composition according to claim 14, wherein the composition consists of said hydraulic binder and one or more polyalkyleneimine(s).

16. The composition according to claim 14, further comprising water.

17. The composition according to claim 16, wherein a mass ratio water/binder is between 0.3 and 0.8.

18. The composition according to claim 14, further comprising metal elements.

19. The composition according to claim 18, wherein the metal elements are reinforcements.

20. The composition according to claim 14, wherein the polyalkyleneimine is a polyethyleneimine or a polypropyleneimine.

21. The composition according to claim 14, wherein the polyalkyleneimine is a polyethyleneimine.

22. The composition according to claim 14, wherein the clinker is a Portland clinker.

23. The composition according to claim 14, wherein the mass proportion of clinker in the hydraulic binder is between 5% and 95% relative to the mass of said binder.

24. The composition according to claim 14, wherein the mass proportion of clinker in the hydraulic binder is between 30% and 85%, relative to the mass of said binder.

25. The composition according to claim 14, wherein the weight ratio polyalkyleneimine(s)/binder is between 0.1% and 4.0%.

26. The composition according to claim 25, wherein the weight ratio polyalkyleneimine(s)/binder is between 0.15% and 3.0%.

27. The composition according to claim 26, wherein the weight ratio polyalkyleneimine(s)/binder is between 0.2% and 1.5%.

28. The composition according to claim 14, wherein the weight ratio polyalkyleneimine(s)/binder is between 0.15% and 3.0%.

29. The composition according to claim 14, wherein the hydraulic binder further comprises at least one mineral addition.

30. The composition according to claim 29, wherein said at least one mineral addition is chosen from the group consisting of slags, pozzolans, fly ash, calcinated shales, calcium carbonate based materials, silica fumes, metakaolins, biomass ash and mixtures thereof.

31. A method for manufacturing a composition according to claim 14, comprising a step of contacting at least one hydraulic binder, comprising at least one clinker, with at least one branched polyalkyleneimine, having a molecular weight from 400 g/mol to 1 000 000 g/mol, at a weight ratio polyalkyleneimine(s)/binder between 0.05% and 5.0%.

32. The method for manufacturing a composition according to claim 14, wherein the polyalkyleneimine(s) is (are) implemented as an aqueous solution.

33. A method comprising utilizing at least one branched polyalkyleneimine, having a molecular weight between 400 g/mol and 1,000,000 g/mol, for reducing and/or preventing carbonation within a hydraulic composition comprising at least one hydraulic binder, said polyalkyleneimine(s) being present in the hydraulic composition at a weight ratio polyalkyleneimine(s)/binder between 0.05% and 5.0%.

34. An object shaped for the construction field obtained from a composition according to claim 14.

Description

EXAMPLES

Example 1

Preparation of Cylindrical Mortar Specimens

[0112] Cylindrical mortar specimens have been prepared from a hydraulic composition comprising a low clinker level hydraulic binder (substituted by 35% of a limestone filler). The water/binder ratio is 0.55 and the TiBP, TrilsoButyl Phosphate (antifoam agent) dose is 0.09%/binder.

[0113] The composition of the test pieces is indicated in table 1 and characteristic of the cement and sand are indicated in tables 2 and 3.

TABLE-US-00001 TABLE 1 Solid Mass of a content concrete Raw materials density (%) mix (g) Hydraulic Portland cement 3.1 100 552.6 binder CEM I 52.5 N CE CP2 NF Limestone filler 2.7 100 297.6 Betocarb HP St Beat provided by the OMYA company (density = 2.7) Total binder 850.2 Sand Standard sand 2.63 100 2,700 Water Pre-wetting water 1 0 162 (tap water at 20 C.) Mixing water 1 0 317 (tap water at 20 C.) Adjuvants TriisoButylPhosphate (TiBP) 0.965 99 0.8 (antifoam agent) Branched PEI Total 4,030

TABLE-US-00002 TABLE 2 Characteristics of the CEM I 52.5 N CE CP2 NF, Saint Pierre La Cour Total K.sub.2O 1.08 % Total Na2O 0.24 % Soluble K.sub.2O 0.85 % Soluble Na.sub.2O 0.1 % SiO.sub.2 20.07 % Al.sub.2O.sub.3 4.95 % Fe.sub.2O.sub.3 2.96 % CaO 63.89 % MgO 0.89 % K.sub.2O 1.06 % Na.sub.2O 0.25 % SO.sub.3 3.41 % TiO.sub.2 0.19 % Mn.sub.2O.sub.3 0.14 % P.sub.2O.sub.5 0.27 % Cr.sub.2O.sub.3 0.02 % ZrO.sub.2 0.02 % SrO 0.02 % PAF 1.56 % Total 99.7 % Free CaO 1.59 % Insolubles 0.32 % SO.sub.3 Horiba 3.39 % Cement model granulo laser curve D10 2.79 m D50 14.35 m D90 43.92 m D(4.3) 19.6 m Density of a solid- 3.12 g/cm.sup.3 Physics Specific surface area 3,750 cm.sup.2/g BLAINE - Physics Mono alite 60 % Belite 17.8 % Ferrite 9.3 % Cubic aluminate 4.4 % Ortho aluminate 3 % Lime CaO 0.2 % Portlandite Ca(OH)2 1.5 % Periclase 0 % Arcanite not calc % Quartz 0 % Calcite 0.8 % Gypsum 0.5 % Semi-hydrate 2.4 % Anhydrite 0 % Dolomite not calc % Phase X not calc % Gypsum (by DSC) 0.4 % Semi hydrate (by DSC) 3 % Total CO.sub.2 0.24 % Total H.sub.2O 1.01 % Atmosphere Nitrogen unitless

TABLE-US-00003 TABLE 3 Characteristics of the standard stand (EN 12620) Unit Value Characteristics (EN 12620) Vibrated compactness 0.696 Adsorption coefficient % 0.42 Real density t/m.sup.3 2.63 Methylene blue value g/kg 0 Particle size (EN 12620) Passing through 4 mm % 100 Passing through 2.8 mm % 100 Passing through 2.5 mm % 100 Passing through 2 mm % 99 Passing through 1 mm % 70.62 Passing through 500 m % 30.95 Passing through 250 m % 19.15 Passing through 125 m % 7.84 Passing through 63 m % 0

[0114] The branched polyethyleneimines (PEI) of table 4 have been used in various (mass) proportions with respect to the hydraulic binder.

TABLE-US-00004 TABLE 4 Molecular Solid Nitrogen Carbon weights content content content Name Supplier (g/mol) (%) (% solids) (% solids) PEI600 Sigma- 600 99 25.9 55.9 Aldrich Lupasol BASF 1,300 49 27.0 59.0 G20 (PEI1300) Lupasol BASF 5,000 49 25.7 60.2 G100 (PEI5000) PEI25000 Sigma- 25,000 99 23.9 57.9 Aldrich PEI600000 Sigma- 600,000 50 26.3 64.1 Aldrich

Preparation Protocol

[0115] The sand has been put in the bowl of a 32 type Perrier kneader with pre-wetting water. Mixing has started and has been maintained at a low speed for 1 minute.

[0116] Mixing has then been stopped for 4 minutes.

[0117] The hydraulic binder (clinker +filler) has been added and mixing has been resumed at a low speed for 1 minute.

[0118] The mixing water, comprising the adjuvants (branched polyethylemeneimine and antifoam), has then been added within 30 seconds while mixing at a low speed.

[0119] The mixture has been mixed at a high speed for 1 minute, to obtain a mortar.

[0120] The mortar has then been cast in polystyrene moulds with dimensions 4 cm4 cm16 cm (without vibration), in order to obtain 6 concrete test pieces (demould released after 24 h at 20 C. at 100% relative humidity).

Example 2

Measurement of Carbonation of the Cylindrical Mortar Specimens

Measurement Protocol

[0121] The cylindrical mortar specimens have then been placed under accelerated carbonation conditions.

[0122] After 6 days of curing in a wet cabinet at 100% relative humidity and 20 C., the test pieces have been put in a carbonation box (PEHD rectangular vessel, 576 litres capacity, provided with a sealed lid), the atmosphere of which has been enriched with CO.sub.2 (10%+/0.5% CO.sub.2 in the air volume of the box), 20 C.+/1 C. and 65%+/5% of relative humidity.

[0123] The temperature control has been ensured by the fact that the box is disposed in a laboratory controlled at 20+/1 C. The relative humidity rate has been controlled by a vat filled with a water-saturated ammonium nitrate salt, this vat being positioned in the bottom of the box, on the entire available surface. For the CO.sub.2, the box has been connected to a network supplied with bottles filled with a 50% CO.sub.2/50% pressurised nitrogen mixture. An expansion station enabled the mixture to be delivered at 1 bar of relative pressure in the network. The gas introduction has been automatically managed by a CO.sub.2 gas analyser which continuously analysed the box atmosphere (wall analyser, brand ABISS, model LMP 320, provided by the PBI Datasensor company). At each gas introduction, another solenoid valve opened to discharge extra gas to a crawl space external to the laboratory, in order to avoid any overpressure in the box. A fan continuously operated to have homogeneous CO.sub.2 gas distribution in the box atmosphere.

[0124] At different points in time (at 2, 3, 4, 7, 13, 14, 28, and at 35 days), the test pieces have been removed from the carbonation box and slit using a hydraulic stone cutter for determining the carbonation depth.

[0125] The carbonation resistance has been estimated by measuring the carbonation rate of the test pieces. The higher this rate, the lesser resistant to a carbonation the concrete, and the higher the corrosion risk of the structure reinforcements. This rate has been measured by determining the depth of carbonated concrete after different exposition periods of the test pieces in the box enriched with CO.sub.2 gas. The material is considered as carbonated when its pH is lower than or equal to 9. This has been viewed by spraying a 0.5% phenolphthalein solution diluted in a mixture comprised of 50% demineralised water and 50% ethanol. Phenolphthalein is a colour indicator which turns purple pink when the pH is higher than 9 and remains colourless when the pH is lower than 9. Carbonated concrete zones are thus those which remain colourless after spraying the phenolphthalein suspension. The carbonated concrete and mortar depths have been measured at several zones. The arithmetic mean of the values obtained has been calculated.

[0126] The carbonation rate is expressed in mm/day.sup.1/2. It is the slope of the straight line obtained when the evolution of the carbonation depth (in mm) versus the square root of time (in days) is represented.

Results

[0127] The results of the measurement of the carbonation rate (mm/day.sup.1/2) as a function of the proportion (%/binder) and the molecular weight (g/mol) of PEI are indicated in table 5:

TABLE-US-00005 TABLE 5 Molecular weight of the PEIs (g/mol) PEI/binder (%) 600 1,300 5,000 25,000 600,000 0 (reference) 3.1 3.1 3.1 3.1 3.1 0.25 3.1 2.5 2.7 2.8 2.8 0.5 3.1 2.1 2.6 2.6 2.7 1 3 2 2.4 2.5 2.5 2 1.7 1.7 1.7 5 2.9 1.6 1.6 1.9

[0128] All the PEIs and doses with respect to the binder resulted in reduced carbonation rates with respect to the reference without PEI.

[0129] It has been observed that the carbonation rate decreases when the mass proportion of PEI with respect to the binder increases.