FLUIDIZING MIX FOR A COMPOSITION WITH A BASE OF HYDRAULIC BINDER

Abstract

The present invention relates to a hydraulic composition comprising: at least one hydraulic binder; at least one first water-reducing additive comprising at least one phosphonic amino-alkylene group; at least one second water-reducing additive comprising at least one polymer with a comb structure, the concentration by weight of dry extract of the second additive being from 25% to 100% of the concentration by weight of dry extract of the first additive.

A concrete comprising such a hydraulic composition and a fluidizing mix for such a hydraulic composition are two other aspects of the present invention.

Claims

1.-14. (canceled)

15. A method to reduce the setting start time of a hydraulic composition comprising at least one hydraulic binder and at least one first water-reducing additive comprising at least one phosphonic amino-alkylene group, the method comprising adding at least one second water-reducing additive comprising at least one polycarboxylate of polyoxyalkylene of methacrylic acid with a comb structure to the hydraulic composition and the concentration by weight of dry extract of the second water-reducing additive being in a range from 30% to 95% of the concentration by weight of dry extract of the first water-reducing additive.

16. The method according to claim 15, wherein the concentration by weight of dry extract of the second water-reducing additive is in a range from 30% to 90% of the concentration by weight of dry extract of the first water-reducing additive.

17. The method according to claim 15, wherein the concentration by weight of dry extract of the second water-reducing additive is in a range from 40% to 90% of the concentration by weight of dry extract of the first water-reducing additive.

18. The method according to claim 15, wherein the first water-reducing additive corresponds to the formula: ##STR00006## in which: R is a hydrogen atom or a monovalent hydrocarbon group with 1 to 18 carbon atoms and optionally one or more hetero atoms; the R.sub.i are similar or different and represent an alkylene for example ethylene, propylene, amylene, octylene or cyclohexene or an arylene, for example styrene or methylstyrene, the R.sub.i optionally comprising one or more hetero atoms; Q is a hydrocarbon group with 2 to 18 carbon atoms and optionally one or more hetero atoms; A is an alkylidene group with 1 to 5 carbon atoms; the are similar or different and may be selected from: the A-PO.sub.3H.sub.2 group, A having the aforesaid meaning; an alkyl group with 1 to 18 carbon atoms and being able to carry [RO(R.sub.iO).sub.n] groups, R and R.sub.i having the aforesaid meanings; and the group: ##STR00007## R.sub.k designating a group like Rj chosen among: the A-PO.sub.3H.sub.2 group, A having the aforesaid meaning; and an alkyl group with 1 to 18 carbon atoms and being able to carry [RO(R.sub.iO).sub.n] groups, R and R.sub.i having the aforesaid meanings; B designating an alkylene group with 2 to 18 carbon atoms; n is a number greater than or equal to 0; r is the sum of the [RO(R.sub.iO).sub.n] groups carried by all the R.sub.j; q is the number of [RO(R.sub.iO).sub.n] groups carried by Q; the sum r+q is from 1 to 10; y is an integer from 1 to 3; Q, N and the can form together one or more cycles, this or these cycles further being able to contain one or more other hetero atoms.

19. The method according to claim 15, wherein the first water-reducing additive corresponds to the formula: ##STR00008## in which: M is a linear or branched hydrocarbon group optionally comprising one or more hetero atoms; Q is a hydrocarbon group with 2 to 18 carbon atoms and optionally one or more hetero atoms; p is the number of [M] groups carried by Q, p being from 1 to 10; and y is an integer from 1 to 3.

20. The method according to claim 15, wherein the concentration of the second water-reducing additive relative to the first water-reducing additive is such that a dosage of a mixture of said first and second water-reducing additives in said hydraulic composition to obtain an initial spread or slump is less than a dosage of only said first water-reducing additive in said hydraulic composition that is used to obtain said initial spread or slump.

21. The method according to claim 20, wherein a setting start time of said hydraulic composition is less than 50% of that obtained with said dosage of only said first water-reducing additive in said hydraulic composition.

22. The method according to claim 20, wherein said dosage of the mixture is less than 50% of said dosage of only said first water-reducing additive.

Description

[0081] Examples of embodiments will now be described with reference to the figures, of which:

[0082] FIG. 1 represents the theoretical and real evolutions of the dosage of a fluidizing mix in a hydraulic composition relative to the percentage of the second additive in the fluidizing mix to obtain a given initial spread; and

[0083] FIG. 2 represents the evolutions of the viscosity and the setting time of the hydraulic composition corresponding to FIG. 1 relative to the percentage of the second additive in the fluidizing mix.

METHOD TO MEASURE THE SPREAD OF A HYDRAULIC COMPOSITION

[0084] The principle of the spread measurement consists in filling a truncated spread measurement cone with the hydraulic composition to be tested, then releasing the said composition from the said truncated spread measurement cone in order to determine the surface of the obtained disk when the hydraulic composition has finished spreading. The truncated spread measurement cone corresponds to a reproduction at the scale of the cone as defined by the NF P 18-451 Standard, 1981. The truncated spread measurement cone has the following dimensions: [0085] top diameter: 50+/0.5 mm; [0086] bottom diameter: 100+/0.5 mm; and [0087] height: 150+/0.5 mm.

[0088] The entire operation is carried out at 20 C. The spread measurement is carried out in the following manner: [0089] Fill the reference cone in one single time with the hydraulic composition to be tested; [0090] If necessary, tap the hydraulic composition to homogenously distribute it in the truncated cone; [0091] Level the top surface of the cone; [0092] Lift the truncated cone vertically; and [0093] Measure the spread according to four diameters at 45 with a caliper square. The result of the spread measurement is the average of the four values, +1-1 mm.

METHOD TO MEASURE THE VISCOSITY OF A HYDRAULIC COMPOSITION

[0094] The viscosity measurement consists in measuring the flow time through a truncated viscosity measurement cone of a hydraulic composition to be tested. The truncated viscosity measurement cone has the following dimensions: [0095] larger diameter: 150 mm; and [0096] smaller diameter: 17 mm.

[0097] The truncated viscosity measurement cone further comprises first and second marks which may be parallel marks provided on the sides of the truncated cone and defining planes perpendicular to the axis of the truncated cone. The first mark is closer to the base of the larger diameter than the second mark. The distance between the two marks is 60 mm, the first mark being at 12 mm from the base with the larger diameter.

[0098] The entire operation is carried out at 20 C. The viscosity measurement of a hydraulic composition is carried out in the following manner: [0099] Orient the axis of the truncated cone vertically, the smaller diameter being oriented downwards and being obturated by a plug; [0100] Fill the truncated cone with the hydraulic composition up to above the first mark; [0101] Tap the hydraulic composition with a spatula in order to ensure the absence of big air bubbles; [0102] Remove the plug; [0103] Start the stopwatch when the level of hydraulic composition passes the first mark; [0104] Stop the stop watch when the level of hydraulic composition passes the second mark; and [0105] Record the time, which represents the viscosity of the hydraulic composition.

METHOD TO MEASURE THE SETTING START AND SETTING END TIMES OF A MORTAR

[0106] This method is based on the standardized measurement method for determination of the setting time and stability according to the EN 196-3 Standard. It uses an automatic VICAT setting meter as described in the EN 196-3 Standard, a truncated cone and a container. The VICAT setting meter comprises a needle, a plate and a movement mechanism of the needle relative to the plate along the vertical axis. The needle can have the shape of a straight cylinder having a length greater than 45 mm and a diameter of approximately 1.13 mm. The axis of the needle is vertical. The container has bigger dimensions than the mould and is placed on the plate. The mould has a truncated shape. The mould is placed in the container, the axis of the mould coinciding with the rotation axis of the plate.

[0107] The entire operation is carried out at 20 C. The method to measure the setting start and setting end times of the mortar is the following: [0108] Oil the truncated mould using a brush and demoulding oil; [0109] Place this mould into the container; [0110] Fill the mould with mortar; [0111] Level the surface of the mould using a ruler to obtain a flat surface; [0112] Place the mould+container assembly on the plate; [0113] Add an additional mass of 700 g to the needle support; [0114] Move the needle in the mortar, the time between each lowering of the needle being 10 minutes, the movement of the needle corresponding to a free drop from the free surface of the mortar. This operation is repeated 90 times.

[0115] The setting start time corresponds to the time after which the needle falls to only 4 mm1 mm from the bottom of the mould. The time is measured from the moment TO of the method for preparation of the mortar described herein after. The setting end time corresponds to the time after which the needle falls only to 0.5 mm in the mortar. The time is measured from the moment TO of the method for preparation of the mortar described herein after.

METHOD FOR PREPARATION OF THE MORTAR

[0116] The mortar is made using a Perrier type of mixer. The entire operation is carried out at 20 C. The preparation method comprises the following steps: [0117] Put the sands in a mixer bowl; [0118] At T=0 second: start the mixing at low speed (140 rpm) and simultaneously add the wetting water in 30 seconds, then continue to mix at low speed (140 rpm) until 60 seconds; [0119] At T=1 minute: stop the mixing and let rest for 4 minutes; [0120] At T=5 minutes: (TO for the measurement method of the setting time): add the hydraulic binder; [0121] At T=6 minutes: mix at low speed (140 rpm) for 1 minute; [0122] At T=7 minutes: add the mixing water (+first and second additives) in 30 seconds (whilst mixing at low speed (140 rpm)); and [0123] At T=7 minutes and 30 seconds: mix at high speed (280 rpm) for 2 minutes.

Mortar Formulations

[0124] Two mortar formulations were used to carry out these tests.

TABLE-US-00001 TABLE 1 Mortar Formulation 1 Component Mass (g) Cement 480.4 ISO sand 1350 Siliceous sand 200.1 Limestone filler 354.1 Total water, of which: 326.7 mixing water 226.7 sand wetting water 100 Water/Cement ratio 0.68

TABLE-US-00002 TABLE 2 Mortar Formulation 2 Component Mass (g) Cement 480.4 ISO sand 1350 Fine sand 200.1 Limestone filler 340.8 Total water, of which: 297.8 mixing water 197.8 sand wetting water 100 Water/Cement ratio 0.62

[0125] The cement is a Portland cement of the CEM I 52.5 N type produced at the Lafarge Saint-Pierre-La-Cour cement plant.

[0126] The ISO sand is a certified CEN EN 196-1 sand (Supplier: Socit Nouvelle de Littoral). It is a natural siliceous sand, with rounded grains, with a content of silica at least equal to 98%. Its grading composition is within the bounds given in Table 3.

TABLE-US-00003 TABLE 3 Grading composition of the ISO sand Dimensions of the Cumulated oversize squared mesh (mm) on the sieves (%) 2.00 0 1.60 7 5 1.00 33 5 0.50 67 5 0.16 87 5 0.08 99 1

[0127] The limestone filler is the Erbray Filler (Supplier: MEAC). The siliceous sand is the Fulchiron PE2 LS sand (Supplier: Fulchiron).

[0128] Certain properties of a mortar made according to formulation 1 or 2, and comprising a mix of first and second additives for different dosages of the first and second additives were compared in the following examples. The first additive is called Add 1 and corresponds to CHRYSO Fluid Optima 100 (Supplier: Chryso) in the following examples. CHRYSO Fluid Optima 100 is an additive in the family of diphosphonates and the formula of which is similar to formula (2). The second additive is called Add 2 and corresponds to a polymer of the de polyalkylene oxide polycarboxylate type. The concentrations or dosages of the first and second additives are given by weight relative to the weight of the cement. For each mortar, according to the measurement methods described herein above the following elements were measured: [0129] the setting start time; [0130] the spread of the mortar at successive time periods; and [0131] the viscosity of the mortar at successive time periods.

EXAMPLE 1

[0132] A mortar corresponding to formulation 2 was made. The additive Add 2 was CHRYSO Fluid Optima 206 (supplier: Chryso). Three examples of concentrations of additives Add 1 and Add 2 were tested. The obtained results are grouped together in Table 4 herein below:

TABLE-US-00004 TABLE 4 Optima 100/ Dosage Optima 206 Total Dosage Dosage Rheology (mm) Viscosity(ies) Setting (%) dosage Add 1 Add 2 at 5 min at 5 min start time 100/0 0.9% 0.9% 0.0% 305 14 >12 h 50/50 0.34% 0.17% 0.17% 345 24 5 h 45 min 0/100 0.32% 0.00% 0.32% 315 35 4 h 50 min

[0133] The dosage of the additive Add 1 alone, (referred to as dosage_Add_1) corresponds to a given initial spread. The dosage of the additive Add 2 alone, (referred to asdosage_Add_2) corresponds to the same initial spread for this product. The theoretical dosage, dosage_mix of the mix corresponding to the same initial spread and comprising a percentage w % Add_1 by weight of the additive Add 1 and a percentage w % Add_2 by weight of the additive Add 2 can be given by the law of mixes according to the following relation:

[00001]$\frac{1}{\mathrm{dosage\_mix}}=\frac{w.Math..Math.\%.Math..Math.\mathrm{Add\_}.Math.1}{\mathrm{dosage\_Add}.Math.\_.Math.1}+\frac{w.Math..Math.\%.Math..Math.\mathrm{Add\_}.Math.2}{\mathrm{dosage\_Add}.Math.\_.Math.2}$

[0134] In the present example, the theoretical dosage of the fluidizing mix comprising 50% by weight of the additive Add 1 and 50% by weight of the additive Add 2 would be 0.49% by weight relative to the weight of the cement to obtain an initial spread of the order of 320 mm. The real obtained dosage was 0.34% by weight relative to the weight of the cement. The Applicant therefore showed that, surprisingly, the real dosage of a mix comprising 50% by weight of the additive Add 1 and 50% by weight of the additive Add 2 to obtain a given initial spread is less than the expected theoretical dosage. Furthermore, the initial viscosity (at 5 minutes) of the mortar comprising the additives Add 1 and Add 2 was, advantageously, less than the initial viscosity of the mortar only comprising the additive Add 2. Furthermore, the setting start time of the mortar comprising the additives Add 1 and Add 2 was, advantageously, clearly lower than the setting start time of the mortar only comprising the additive Add 1 and only slightly higher than the setting start time of the mortar only comprising the additive Add 2.

EXAMPLE 2

[0135] A mortar corresponding to formulation 1 was made. The additive Add 2 was CHRYSO Fluid Optima 206 (supplier: Chryso). Three examples of concentrations of additives Add 1 and Add 2 were tested. The obtained results are grouped together in Table 5 herein below:

TABLE-US-00005 TABLE 5 Optima 100/ Dosage Optima 206 Total Dosage Dosage Rheology (mm) Viscosity(ies) Setting (%) dosage Add 1 Add 2 at 5 min at 5 min start time 100/0 0.75% 0.75% 0.00% 320 8 >15 h 50/50 0.24% 0.12% 0.12% 330 13 5 h 45 min 0/100 0.24% 0.0% 0.24% 340 18 5 h 30 min

[0136] In the present example, the theoretical dosage of the fluidizing mix comprising 50% by weight of the additive Add 1 and 50% by weight of the additive Add 2 would be 0.36% by weight relative to the weight of the cement to obtain an initial spread of the order of 330 mm. The real obtained dosage was 0.24% by weight relative to the weight of the cement. The Applicant therefore showed that, surprisingly, the real dosage of a mix comprising 50% by weight of the additive Add_1 and 50% by weight of the additive Add_2 to obtain a given initial spread is less than the expected theoretical dosage. Furthermore, the initial viscosity (at 5 minutes) of the mortar comprising the additives Add 1 and Add 2 was, advantageously, less than the initial viscosity of the mortar only comprising the additive Add 2. Furthermore, the setting start time of the mortar comprising the additives Add 1 and Add 2 was, advantageously, clearly lower than the setting start time of the mortar only comprising the additive Add 1 and was of the same order as the setting start time of the mortar only comprising the additive Add 2.

EXAMPLE 3

[0137] A mortar corresponding to formulation 1 was made. The additive Add 2 was the methacrylic PCP. Six examples of concentrations of the additives Add 1 and Add 2 were tested. The obtained results are grouped together in Table 6 herein below and illustrated in FIGS. 1 and 2:

TABLE-US-00006 TABLE 6 Optima 100/ Dosage PCP Total Dosage Dosage Rheology (mm) Viscosity(ies) Setting (%) dosage Add 1 Add 2 at 5 min at 5 min start time 100/0 0.75% 0.75% 0.00% 320 8 >15 h 80/20 0.30% 0.24% 0.06% 340 11 6 h 45 min 50/50 0.24% 0.12% 0.12% 345 14 5 h 55 min 30/70 0.24% 0.05% 0.19% 335 16 6 h 00 min 10/90 0.24% 0.03% 0.21% 335 16 5 h 46 min 0/100 0.24% 0.00% 0.24% 340 15 5 h 50 min

[0138] In FIG. 1, the curve C1 represents the theoretical evolution of the dosage of the fluidizing mix in the mortar relative to the percentage of the second additive in the fluidizing mix in order to obtain a given initial spread of approximately 330 mm. Curve C1 was obtained from the mixing law described herein above. In the present example, surprisingly, the real dosage of the fluidizing mix was less than the theoretical dosage of the composition to obtain an initial spread of the order of 330 mm. Furthermore, at least until reaching a percentage of the first additive less than 75% by weight in the fluidizing mix, the dosage of the fluidizing mix only very slightly increased relative to the dosage of the fluidizing mix comprising 100% by weight of the second additive. Furthermore, for a dispersing composition comprising at least 50% by weight of the additive Add 1, the viscosity of the mortar comprising the additives Add 1 and Add 2 was, advantageously, close to the viscosity of the mortar only comprising the additive Add 1 and was lower than the initial viscosity of the mortar only comprising the additive Add 2. Furthermore, the setting start time of the mortar comprising the additives Add 1 and Add 2 was, advantageously, clearly lower than the setting start time of the mortar only comprising the additive Add 1 and was only higher by approximately one hour (for a dispersing composition comprising 80% by weight of the additive Add 1) relative to the setting start time of the mortar only comprising the additive Add 2.

[0139] Therefore, when the concentration by weight of dry extract of the second additive is from 25% to 100% of the concentration by weight of dry extract of the first additive, simultaneously the following results are obtained: [0140] a slump similar to the one which would be obtained in the case where only the first additive had been used; [0141] a dosage of the fluidizing mix in the hydraulic composition less by more than 50% than what would be obtained in the case where only the first additive had been used; [0142] a setting delay less by more than 50% than the setting delay which would be obtained in the case where only the first additive had been used; and [0143] a viscosity less by more than 15% than what would be obtained in the case where only the first additive had been used.