ACCELERATOR COMPOSITION

Abstract

The invention relates to a process for producing a composition suitable as accelerator for the curing of cement, by contacting the components aa) at least one component selected from the series of hydraulic binders and/or latent hydraulic binders, and bb) at least one dispersant suitable for the dispersing of inorganic particles in water, and cc) water, the weight ratio of components aa) to cc) being between 1.5:1 and 1:70, wherein the rate ratio of components aa) to bb) is between 20:1 and 1:2. In addition, the use of the composition obtained as hardening acceleration for chemical mixtures in construction is disclosed.

Claims

1. A process for producing a composition suitable as an accelerator for curing cement, the process comprising contacting aa) at least one component selected from the group consisting of a hydraulic binder and a latent hydraulic binder, and bb) at least one dispersant for dispersing inorganic particles in water, and cc) water, wherein a weight ratio of components aa) to cc) ranges from 1.5:1 to 1:70, and a weight ratio of components aa) to bb) ranges from 20:1 to 1:2.

2. The process according to claim 1, wherein said at least one dispersant comprises a water-soluble polymer having polyether groups of structural unit (I)
*U(C(O)).sub.kX-(AlkO).sub.nW(I) where * represents a bonding site to the polymer, U is a chemical bond or an alkylene group having 1 to 8 carbons, X is oxygen, sulfur or a group NR.sup.1, where R.sup.1 is hydrogen, C.sub.1-C.sub.4 alkyl or benzyl, k is 0 or 1, n is an integer whose average value, based on the polymer, ranges from 3 to 300, Alk is each independently a C.sub.2-C.sub.4 alkylene, and W is a hydrogen, a C.sub.1-C.sub.6 alkyl, an aryl radical, or is a Y-F group, where Y is a linear or branched alkylene group having 2 to 8 carbons and optionally a phenyl ring, F is a 5- to 10-membered nitrogen heterocycle which is bonded via nitrogen and which as ring members, besides the nitrogen atom and carbon atoms, optionally has 1, 2 or 3 additional heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur; optionally the nitrogen ring members have a group R.sup.2, which is hydrogen, a C.sub.1-C.sub.4 alkyl or benzyl; and 1 or 2 carbon ring members are present in the form of a carbonyl group.

3. The process according to claim 1, wherein said at least one dispersant comprises at least one group selected from the group consisting of a carboxyester group, a carboxyl group, a phosphono group, a sulfino group, a sulfo group, a sulfamido group, a sulfoxy group, a sulfoalkyloxy group, a sulfinoalkyloxy group, and a phosphonooxy group.

4. The process according to claim 1, wherein said at least one dispersant comprises a polycondensation product comprising (II) a structural unit containing an aromatic or heteroaromatic group and a polyether group, and (III) a phosphated structural unit containing an aromatic or heteroaromatic group.

5. The process according to claim 4, wherein the structural unit (II) is represented by formula
A-U(C(O)).sub.kX-(AlkO).sub.nW where each A is independently a substituted or unsubstituted, aromatic or heteroaromatic compound having 5 to 10 carbons in the aromatic system, U is a chemical bond or an alkylene group having 1 to 8 carbons, X is oxygen, sulfur or a group NR.sup.1, where R.sup.1 is hydrogen, C.sub.1-C.sub.4 alkyl or benzyl, k is 0 or 1, each Alk is independently a C.sub.2-C.sub.4 alkylene, n is an integer whose average value, based on the polymer, ranges from 3 to 300, W is a hydrogen, a C.sub.1-C.sub.6 alkyl, an aryl radical, or is a Y-F group, where Y is a linear or branched alkylene group having 2 to 8 carbons and optionally a phenyl ring, F is a 5- to 10-membered nitrogen heterocycle which is bonded via nitrogen and which as ring members, besides the nitrogen atom and carbon atoms, optionally has 1, 2 or 3 additional heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur; optionally the nitrogen ring members have a group R.sup.2 which is hydrogen, a C.sub.1-C.sub.4 alkyl or benzyl; and 1 or 2 carbon ring members are present in the form of a carbonyl group; and the structural unit (III) is represented by formula ##STR00008## where each D is independently a substituted or unsubstituted, aromatic or heteroaromatic compound having 5 to 10 carbons in the aromatic system, E is independently N, NH or O, m=2 if E=N and m=1 if E=NH or O, each R.sup.3 and each R.sup.4 are independently a branched or unbranched C.sub.1 to C.sub.10 alkyl radical, C.sub.5 to C.sub.8 cycloalkyl radical, aryl radical, heteroaryl radical or H, and each b is independently an integer from 0 to 300.

6. The process according to claim 4, wherein the polycondensation product comprises a further structural unit (IV) represented by formula ##STR00009## where each Y is independently the structural unit (II), the structural unit (III), or a further constituent of the polycondensation product.

7. The process according to claim 1, wherein said at least one dispersant comprises at least one copolymer which is obtained by polymerization of a mixture of monomers comprising (V) at least one ethylenically unsaturated monomer which comprises at least one radical selected from the group consisting of a carboxylic acid, a carboxylic salt, a carboxylic ester, a carboxylic amide, a carboxylic anhydride, and a carboxylic imide; and (VI) at least one ethylenically unsaturated monomer comprising a polyether group.

8. The process according to claim 7, wherein the ethylenically unsaturated monomer (V) is at least one selected from the group consisting of (Va), (Vb), and (Vc) ##STR00010## where R.sup.7 and R.sup.8 independently of one another are hydrogen or an aliphatic hydrocarbon radical having 1 to 20 carbons; B is H, COOM.sub.a, COO(C.sub.qH.sub.2qO).sub.rR.sup.9, CONH(C.sub.qH.sub.2qO).sub.rR.sup.9, where M is hydrogen, a mono-, di- or trivalent metal cation, ammonium ion or an organic amine radical, a is , or 1, R.sup.9 is hydrogen, an aliphatic hydrocarbon radical having 1 to 20 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an optionally substituted aryl radical having 6 to 14 carbons, q independently for each (C.sub.qH.sub.2qO) unit is 2, 3 or 4, and r is 0 to 200; Z is O, NR.sup.16, where R.sup.16 independently at each occurrence is represented by a branched or unbranched C.sub.1 to C.sub.10 alkyl radical, C.sub.5 to C.sub.8 cycloalkyl radical, aryl radical, heteroaryl radical or H, ##STR00011## where R.sup.10 and R.sup.11 independently of one another are hydrogen, an aliphatic hydrocarbon radical having 1 to 20 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, or an optionally substituted aryl radical having 6 to 14 carbons; R.sup.12 is independently (C.sub.nH.sub.2n)SO.sub.3H with n=0, 1, 2, 3 or 4, (C.sub.nH.sub.2n)OH with n=0, 1, 2, 3 or 4; (C.sub.nH.sub.2n)PO.sub.3H.sub.2 with n=0, 1, 2, 3 or 4, (C.sub.1H.sub.2n)OPO.sub.3H.sub.2 with n=0, 1, 2, 3 or 4, (C.sub.6H.sub.4)SO.sub.3H, (C.sub.6H.sub.4)PO.sub.3H.sub.2, (C.sub.6H.sub.4)OPO.sub.3H.sub.2 or (C.sub.nH.sub.2n)NR.sup.14.sub.b with n=0, 1, 2, 3 or 4 and b=2 or 3; R.sup.13 is H, COOM.sub.a, COO(C.sub.qH.sub.2qO).sub.rR.sup.9, CONH(C.sub.qH.sub.2qO).sub.rR.sup.9, where M, a, R.sup.9, q and r possess definitions stated above; R.sup.14 is hydrogen, an aliphatic hydrocarbon radical having 1 to 10 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an optionally substituted aryl radical having 6 to 14 carbons; and Q is independently NH, NR.sup.15 or O, where R.sup.15 is an aliphatic hydrocarbon radical having 1 to 10 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons or an optionally substituted aryl radical having 6 to 14 carbons.

9. The process according to claim 1, wherein said at least one dispersant comprises at least one water-soluble polymer which has an average molar weight (Mw) of between 5000 and 150 000 g/mol as determined by gel permeation chromatography.

10. The process according to claim 1, where the components aa) bb), and cc) are contacted with one another until suspended matter fraction M is greater than 25 wt %, wherein M is determined by a method comprising: a) preparing a suspension by making up 2 grams of the composition, based on solids fraction, to a volume of 100 ml with distilled water, b) transferring the suspension to a measuring cylinder to reach a height of 20 cm in the cylinder, c) leaving the cylinder to stand at 20 C. for 24 hours, d) fully decanting supernatant into a beaker, e) carrying out quantitative determination of mass m and solids content SC for sediment and the supernatant in the cylinder represented by m.sub.sediment, SC.sub.sediment m.sub.supernatant, and SC.sub.supernatant, respectively and calculating the suspended matter fraction M as follows:
M=SC.sub.supernatant.Math.m.sub.supernatant/(SC.sub.sediment.Math.m.sub.sediment.Math.SC.sub.supernatant.Math.m.sub.supernatant).Math.100%.

11. The process according to claim 1, wherein said contacting takes place with introduction of shearing energy of more than 100 kWh per metric ton of the composition.

12. The process according to claim 1, wherein the weight ratio of components aa) to bb) ranges from 10:1 to 1:2.

13. The process according to claim 1, wherein said component aa) is a hydraulic binder.

14. A method for accelerating hardening of a chemical mixture in construction, the method comprising: adding a composition into the chemical mixture, wherein the composition comprises aa) at least one component selected from the group consisting of a hydraulic binder and a latent hydraulic binder, bb) at least one dispersant for dispersing inorganic particles in water, and cc) water, a weight ratio of components aa) to cc) ranges from 1.5:1 to 1:70, and a weight ratio of components aa) to bb) ranges from 20:1 to 1:2.

Description

EXAMPLES

[0117] Determination of Suspended Matter Fraction M

[0118] The suspended matter fraction M describes the tendency of the particulate suspension to undergo sedimentation, and is obtained from the ratio of the solids in the supernatant after a certain time to the solids in the suspension as a whole. To determine the suspended matter fraction M, the following steps are carried out: [0119] a) Determination of the empty weight m.sub.0 of a 100 ml measuring cylinder [0120] b) Preparation of a suspension by placing 2 grams of the inventive composition, based on the solids fraction, into the cylinder, making up the cylinder to a volume of 100 ml with distilled water, and homogenizing the suspension by shaking. The aim of the dilution step is to reduce the particle-particle interactions during sedimentation in the field of gravity, and so allowing the sedimentation process to proceed in accordance with Stokes' law. The height of the suspension in the measuring cylinder here reaches 20 cm. [0121] c) The suspension is left to stand at 20 C. for 24 hours. During this time the cylinder is covered in order to minimize evaporation of water. [0122] d) After 24 hours, the supernatant is separated from the settled sediment by decanting. This is done by transferring the supernatant into a beaker provided, whose empty weight m.sub.0(supernatant) has been determined beforehand. It is very important here to avoid remixing of the settled sediment with the supernatant. Mixing of the sediment with supernatant would falsify the determination of the suspended matter fraction M. [0123] e) The mass of sediment m.sub.sediment is determined after decanted by weighing of the cylinder, including sediment, and subtraction of the empty weight m.sub.0 of the cylinder. [0124] f) The mass of the supernatant m.sub.supernatant determined after decanting by weighing of the beaker including the supernatant and subtraction of the empty weight of the beaker m.sub.0(supernatant). [0125] g) Sediment and supernatant are homogenized again [0126] h) A sample is taken from each of the sediment and the supernatant, and the solids content of each such sample is determined by drying to constant weight at 105 C. This is preferably done using a drying balance with infrared heating. [0127] The solids content may alternatively also be determined by storage of the sample in a drying cabinet at 105 C. for 6 hours. The drying then gives, accordingly, the solids contents for the supernatant SC.sub.supernatant and for the sediment SC.sub.sediment. [0128] i) Lastly, from the values determined, the suspended matter fraction M is calculated as follows:

M=SC.sub.supernatant.Math.m.sub.supernatant/(SC.sub.sediment.Math.m.sub.sediment.Math.SC.sub.supernatant.Math.m.sub.supernatant).Math.100%.

[0129] The higher the suspended matter fraction M, the fewer the particles which have undergone sedimentation after 24 hours. Accordingly, a suspended matter fraction M of 100% indicates that the inventive suspension exhibits no sedimentation at all.

[0130] Calorimetry

[0131] To estimate the acceleration performance of the samples, measurements were carried out by isothermal heat flow calorimetry on the TAMAir instrument from TA Instruments.

[0132] Polymers 1 and 2:

[0133] General protocol for the preparation of polymers 1 and 2:

[0134] A 1-liter four-neck flask with thermometer, reflux condenser and a connection for two feeds is charged with 875 g of 40% strength aqueous polyethylene glycol hydroxybutyl monovinyl ether and NaOH (20%). The details of the molar masses of the respective polyethylene glycol hydroxybutyl monovinyl ethers can be found in table B. Thereafter the solution is cooled to 20 C. Acrylic acid (99%) is now slowly added to the solution of polyethylene glycol hydroxybutyl monovinyl ether in the reservoir flask. The pH here falls to around 4-5. Next, 0.5 g of iron(II) sulfate heptahydrate and also 5 g of Rongalite and mercaptoethanol are added. After brief incorporation by stirring, the metered addition takes place of a further 3 g of 50% of hydrogen peroxide. The temperature here rises from 20 C. to about 30 C. up to 65 C. The solution is subsequently stirred for 10 minutes before being neutralized with aqueous sodium hydroxide solution (20%). The result is a clear aqueous polymer solution with a slight yellow coloration and a variable solids content. All variable quantities for the chemicals used in preparing the polycarboxylate ethers polymer 1 and polymer 2 (NaOH, mercaptoethanol and acrylic acid), and the molar masses of the respective polyethylene glycol hydroxybutyl monovinyl ether can be found in tables A and B below.

TABLE-US-00001 TABLE A details of the preparation of polymers 1 and 2 NaOH (20%) Mercaptoethanol Acrylic acid (99%) [g] [g] [g] Polymer 1 40 6.0 122.8 Polymer 2 20 2.7 84.9

[0135] Table B affords an overview of the structural parameters of the polycarboxylate ethers used as spraying assistants.

TABLE-US-00002 TABLE B overview of the structural parameters of the PCEs Additive Solids content (PCE) A B C (wt %) Polymer 1 1/900 28 537 5800 33.2 Polymer 2 1/372 23 239 3000 35.1 A: Charge density (number of moles of carboxylate and/or carboxyl groups/total molar mass of the PCE) (mol/(g/mol)) B: Weight-average molecular weight M.sub.w (g/mol) C: Molar mass of polyethylene glycol hydroxybutyl monovinyl ether used (g/mol)

[0136] Polymer 3:

[0137] Polymer 3 is a condensate composed of the units phenol PEG5000, phenoxyethanol phosphate and formaldehyde. The molecular weight M.sub.w is 25 730 g/mol. The polymer was prepared in accordance with polymer 7 from WO2015/091461 (tables 1 and 2). The solids content is 33.7 wt %.

[0138] Polymer 4:

[0139] Polymer 4 is a comb polymer polymerized from a hydroxyethyl methacrylate phosphoric ester and an ester of methacrylic acid and methylpolyethylene glycol with a molecular weight of 5000 g/mol. The synthesis was carried out in accordance with the preparation of P1 from WO2014/026938. The molecular weight M.sub.w is 36 600 g/mol. The solids content of the polymer solution is 28.8 wt %.

[0140] BNS:

[0141] BNS is a commercially available dispersant based on naphthalenesulfonate. The product Flube CA 40 from Giovanni Bozetto S.p.A. was used. The solids content is 42 wt %.

[0142] Blank

[0143] 50 g of Milke CEM I 52.5 R were mixed with 40 g of water and homogenized with an IKA paddle stirrer at 750 rpm for 90 seconds. 3 g of this homogeneous cement paste were passed on for isothermal heat flow calorimetry.

Example 1 (Inventive)

[0144] 50 g of Aalborg White Cement CEM I 52.5 R were weighed out into a 2-liter plastic (PE) bottle. Then 40 g of a polycarboxylate ether (dispersant; brand name: Melflux 6681 F) were weighed out into the plastic bottle. Added to this mixture were 900 g of mains water. The bottle was closed with a plastic cap and shaken vigorously by hand until no sediment of still-dry cement was left. Then a magnetic stirring rod was added and the mixture was stirred at 23 C. and 250 revolutions per minute for 2 months. This produces a suspension having a solids content of 10.1 wt %. The solids content is determined by drying the sample at 105 C. to constant mass.

[0145] Suspended matter fraction M: 80.1%

Example 2 (Comparative Example)

[0146] 50 g of Aalborg White Cement CEM I 52.5 R were weighed out into a 2-liter plastic (PE) bottle. Added to the cement were 900 g of mains water. The bottle was closed with a plastic cap and shaken vigorously by hand until no sediment of still-dry cement was left. Then a magnetic stirring rod was added and the mixture was stirred at 23 C. and 250 revolutions per minute for 2 months. In this case a white particulate suspension formed which without being stirred undergoes virtually complete sedimentation within an extremely short time.

[0147] This produces a suspension having a solids content of 6.1 wt %. The solids content is determined by drying the sample at 105 C. to constant mass.

[0148] Suspended matter fraction M: 29.2%

Comparative Example C1

[0149] 100 g of Milke CEM I 52.5 R were mixed with 40 g of water and homogenized for 90 seconds with an IKA paddle stirrer at 500 rpm. 3 g of this homogeneous cement paste was supplied for isothermal heat flow calorimetry.

Comparative Example C2

[0150] 100 g of Milke CEM I 52.5 R were mixed with 12.5 g of the sample from example 2 and 28.26 g of water. The water/cement ratio is therefore 0.4. 3 g of the homogeneous cement paste containing the sample from example 2 were subsequently supplied for isothermal heat flow calorimetry.

Inventive Example

[0151] Cal1 (calorimetry)

[0152] 100 g of Milke CEM I 52.5 R were mixed with 12.5 g of the sample from example 1 and 28.76 g of water. The water/cement ratio is therefore 0.4. 3 g of the homogeneous cement paste containing the sample from example 1 were subsequently supplied for isothermal heat flow calorimetry.

TABLE-US-00003 TABLE 1 summarizes the results: Acceleration factor Cumulative heat of according to hydration after 6 h in Experiment L. Nicoleau (2012) joules/gram (cement) C1 1.00 23.3 C2 1.05 26.4 Cal1 1.75 47.3

[0153] For comparison of the samples, the maximum slopes in the heat flow between 2 and 8 hours were each ascertained and were placed in relation to the slope of comparative measurement C1. The relative slope was determined in accordance with the publication by L. Nicoleau (2012) (L. Nicoleau: The acceleration of cement hydration by seeding: Influence of the cement mineralogy. Ibausil 18.sup.th International Construction Material Conference at Weimar (2012), Conference volume pages 1-0330-1-0337). The heat of hydration here correlates with the development of the early strength of a cement-containing building material mixture (paper by C. Hesse (2014): Small particles with large effectNew pathways of acceleration. 6.sup.th Heidelberg Cement Construction Chemistry days at Munster, Apr. 3/4, 2014, Munster).

[0154] FIG. 1 shows the heat flow in mW/gram of cement over time for experiments C1 and Cal1.

General Example 3: Grinding in a Shaker

[0155] 1000 g of ZrO.sub.2 grinding beads with a diameter of 0.8-1 mm were weighed out into a 0.5 liter Duran glass bottle. The bottle was tared and, for examples 3.1 to 3.11, 20 g of Aalborg White Cement CEM I 52.5 R were added. For examples 3.12 to 3.14, 20 g of a 1:1 (w/w) mixture of Aalborg White CEM I 52.5 R and Salzgitter slag sand were added. In accordance with table 2, a solution of polymers 1, 2, 3, 4 or BNS was added, to give a specific ratio of cement to polymer. The polymer metering here refers to the solids content of polymer in the polymer solution. Subsequently, the mass balance to 200 g was made with up with deionized water. The bottle was closed with a plastic cap. Batches of 4 bottles were fastened in a shaker (SK 300 from Fast & Fluid Management) and shaken for a defined time (cf. table 2). The resulting suspension was poured off into a sieve and the grinding beads were washed with 50 ml of water to remove adhering suspension. The solids content of the suspension was determined by drying the sample at 130 C. to constant weight.

TABLE-US-00004 TABLE 2 shaker grinding Cement*/Polymer Shaken Example Polymer ratio [w/w] for [min] A B C Blank 0 21.3 0.44 3.1 0 120 0 55.1 0.53 3.2 0 240 0 61.0 0.65 3.3 1 4 120 93 77.3 1.24 3.4 1 4 240 93 83.7 1.15 3.5 BNS 100 120 0 56.5 0.58 3.6 1 100 120 0 52.8 0.59 3.7 1 20 120 73 61.7 0.80 3.8 1 10 120 91 68.6 0.97 3.9 2 4 120 62 71.0 1.26 3.10 3 4 120 96 89.3 1.22 3.11 4 4 120 64 84.4 1.14 3.12 0 120 0 56.3 0.66 3.13 1 20 120 43 61.8 0.77 3.14 1 4 120 94 72.0 0.97 A: Suspended matter fraction M in [%] B: Cumulative heat of hydration after 6 h in [joules/gram (cement)] C: Acceleration factor according to L. Nicoleau (2012) [d(HF)/dt] Cement*: Cement refers to Aalborg White Cement CEM I 52.5 R or to the 1:1 (w/w) mixture of Aalborg White CEM I 52.5 R and slag sand

[0156] Examples 3.1 and 3.5 are comparative examples corresponding to DE69407418. Since DE69407418 did not disclose a specific dispersant or any amount for use, the dispersant used in example 3.5 was the standard dispersant BNS in a typically employed amount.

[0157] For examples 3.1, 3.3 and 3.5, the sedimentation factor was determined as instructed in DE69407418: a) the suspension obtained in the examples were transferred to a sedimentation cylinder, so that 10 g are contained, based on the solids content of the suspension. b) Then the suspension volume was made up to 100 ml with deionized water, taking account of the water obtained in the suspension. c) The suspension was homogenized by shaking and left to stand at 20 C. for 48 h. The height of the sedimentation residue was read off on the cylinder.

[0158] Example 3.1: 100%

[0159] Example 3.3: 28%

[0160] Example 3.5: 100%

General Example 4: Grinding in a Stirred Ball Mill

[0161] A 3.0-liter beaker was tared, and 200 g of Aalborg White Cement CEM I 52.5 R were added. Optionally, in accordance with table 3, a polymer solution was added, to give a specific ratio of cement to polymer of 4. The polymer metering here is based on the solids content of polymer in the polymer solution. Subsequently, the balance to a mass of 2000 g was made with deionized water. This suspension was stirred until homogeneous, then placed into the reservoir vessel of the stirred ball mill, and immediately stirred therein with an IKA overhead stirrer so that no separation occurred. Grinding was carried out using a Netzsch LabStar 01 stirred ball mill. Grinding took place in a jacket-cooled grinding chamber (grinding compartment volume of 0.93 liter) with SiC lining, so that the temperature of the suspension is pumped in circulation was 30 C. In the interior of the grinding chamber there was a polyethylene disc stirring mechanism (PU-TriNex-993.06/A4). The grinding chamber was filled with ZrO.sub.2 beads (diameter of 0.8-1.0 mm) to a grinding media fill level of 85 vol %. To obtain this bulk of beads, 586.5 ml of beads were measured out into a measuring cylinder and then introduced into the grinding chamber.

[0162] The suspension was pumped through the stirred ball mill in circulation by means of a peristaltic pump from Ismatec (Ismatec-MCP-Prozess-IP65) for a defined time (cf. table 2) with a pumping capacity (pumping rate) at 22 liters/hour. The speed of rotation of the stirrer of the ball mill was 3500 revolutions per minute.

[0163] When the stipulated grinding time had expired, the ground suspension was introduced into a PE container.

[0164] The specific grinding energy E.sub.m was determined via the following relationship:

[00001]$E_m=P.Math.\frac{t}{m}\left[\mathrm{kWh}.Math.\text{/}.Math.\mathrm{tonne}\right]$

[0165] Where P is the actual recorded shaft power in kilowatts and was read off on the stirred ball mill, t is the grinding time in hours, and m the mass of suspension used and pumped in the circuit.

TABLE-US-00005 TABLE 3 stirred ball mill grinding Grinding Example Polymer time [min] A B C D 4.1 120 0 51.2 0.54 1970 4.2 1 120 92 58.4 0.94 1870 4.3 1 240 92 76.9 1.24 3720 A: Suspended matter fraction M in [%] B: Cumulative heat of hydration after 6 h in [joules/gram (cement)] C: Acceleration factor according to L. Nicoleau (2012) [d(HF)/dt] D: Specific energy E.sub.m in [kWh/ton (suspension)]

[0166] Determination of the Cumulative Heat of Hydration in Examples 3 and 4:

[0167] a) 1 gram, based on the cement content originally present in the suspension, of a suspension from example 3 or 4 was weighed out into a beaker. b) Taking account of the water added through the suspension, the total amount of water was made up with deionized water to 20 g. c) Subsequently, 50 g of Milke CEM I 52.5 R were added. d) The components were homogenized with an IKA paddle stirrer at 750 rpm. e) 3 g of this homogeneous cement paste were passed on for isothermal heat flow calorimetry.