Composition containing a semi-ordered calcium silicate hydrate

Abstract

A curing accelerator composition for building chemical mixtures comprises a mineral constituent and a polymeric water-soluble dispersant. The mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate. The composition displays a more pronounced accelerating effect than comparative compositions in which the mineral component comprises a calcium silicate hydrate having a higher degree of crystallinity.

Claims

1. A composition, comprising a mineral constituent and a polymeric water-soluble dispersant, wherein the mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate.

2. The composition of claim 1, wherein a molar ratio of calcium to silicon in the mineral constituent is in a range of from 0.5 to 2.5.

3. The composition of claim 1, comprising 2% by weight or less of alkali metals, based on the mineral constituent.

4. The composition of claim 1, wherein a specific BET surface area of the mineral constituent is in a range of from 30 to 150 m.sup.2/g, determined in accordance with DIN ISO 9277:2003-05.

5. A process for producing a composition comprising calcium silicate hydrate, the process comprising contacting a mineral constituent with at least one water-soluble polymeric dispersant in an aqueous medium by introducing kinetic energy, where the mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate.

6. The process of claim 5, wherein the mineral constituent has been produced by reacting calcium oxide or calcium hydroxide with silicon dioxide in the presence of water under hydrothermal conditions at a temperature in a range of from 100° C. to 400 C for a period of from 5 hours to 30 hours.

7. The process of claim 6, wherein the mineral constituent has been produced in the presence of a foaming agent.

8. The process of claim 5, wherein the contacting of the mineral constituent with the at least one water-soluble polymeric dispersant is effected by introduction of mixing or shearing energy.

9. The process of claim 8, wherein the contacting of the mineral constituent with the water-soluble polymeric dispersant is effected by milling.

10. The process of claim 9, wherein the milling is carried out to a particle size d(50) of the mineral constituent of ≤400 nm, determined by static light scattering.

11. The process of claim 5, wherein a comb polymer having polyalkylene oxide side chains is used as a polymeric dispersant.

12. A building material mixture, comprising the composition of claim 1 and optionally a hydraulic binder or latent hydraulic binder.

13. A process of accelerating the curing of a building chemical mixture comprising a hydraulic binder or latent hydraulic binder, the process comprising adding the composition of claim 1 to the building chemical mixture.

14. The composition of claim 1, wherein the semi-ordered calcium silicate hydrate has a higher degree of order than amorphous calcium silicate hydrate and a lower degree of order than macroscopic crystalline calcium silicate hydrate.

15. The composition of claim 1, wherein the semi-ordered calcium silicate hydrate has a main diffraction peak with a half width at least 1.25 times the half width of a corresponding main diffraction peak of the crystalline form of calcium silicate hydrate with a crystallite size of 50 nm or larger.

16. A composition, comprising a mineral constituent and a polymeric water-soluble dispersant, wherein the mineral constituent comprises a semi-ordered calcium silicate hydrate having an apparent crystallite size of 15 nm or less and less than 35% by weight of crystalline phases other than the semi-ordered calcium silicate hydrate; wherein the mineral constituent has a molar ratio of Ca to Si in the range of from 1.6 to 2.5.

17. The composition according to claim 16, wherein the composition is a curing accelerator for hydraulic binders or latent hydraulic binders.

Description

(1) The invention will be illustrated by the accompanying drawings and the following examples.

(2) FIG. 1 shows X-ray diffraction spectra of samples comprising (i) crystalline tobermorite 14 Å (crystallite size 50 nm), (ii) amorphous calcium silicate hydrate (tobermorite 14 Å; crystallite size 0.5 nm) and an X-ray diffraction spectrum of a semi-ordered calcium silicate hydrate which is suitable for the purposes of the invention (htCSH3) after Rietveld analysis.

(3) FIG. 2 shows X-ray diffraction spectra of a hydrothermal calcium silicate hydrate (htCSH1, comparison) and two semi-orderedr calcium silicate hydrates (htCSH2 and htCSH3) suitable for the purposes of the invention.

(4) The distinguishable peaks or maxima were assigned to the phases; the abbreviations have the following meanings:

(5) P—portlandite

(6) Cc—calcite

(7) Qz—alpha-quartz

(8) T—tobermorite 14 Å

(9) sCSH—semi-ordered calcium silicate hydrate

(10) aCSH—amorphous calcium silicate hydrate

(11) Xo—xonotlite

(12) As can be seen from FIG. 1, crystalline tobermorite displays a well-resolved spectrum with sharp peaks; no maxima which can be assigned to a crystalline calcium silicate hydrate phase are present in the spectrum of the amorphous calcium silicate hydrate. The contribution of the amorphous calcium silicate hydrate to the X-ray diffraction spectrum can be seen as an increased background, in particular in the 20 range from 25° to 35° (Cu Ka). The semi-ordered calcium silicate hydrate which is suitable for the purposes of the invention displays a broadening and superimposition of the tobermorite maxima around 2θ=30°; the individual peaks are no longer resolved.

(13) As can be seen in FIG. 2, the hydrothermal calcium silicate hydrate htCSH1 displays a well-resolved spectrum with sharp xonotlite peaks. The semi-ordered calcium silicate hydrates htCSH2 and htCSH3 which are suitable for the purposes of the invention display broad maxima around 2θ=30°.

EXAMPLES

(14) Methods of Determination

(15) (i) Particle size of the raw material (mineral constituent) The particle size of the raw material for wet milling was characterized by means of static light scattering. The Mastersizer 2000 instrument from Malvern was used for this purpose.

(16) (ii) Determination of the specific surface area by the BET method The specific BET surface area of the raw material for wet milling was determined by means of nitrogen adsorption. The “NOVA 4000e Surface Area and Pore Size Analyzer” instrument from Quantachrome was used for this purpose. For the measurements, the samples were dried beforehand to constant weight at 105° C.

(17) (iii) X-ray diffraction analysis (XRD) and Rietveld analysis for determination of the proportion of X-ray-amorphous material in and the crystallite size of the calcium silicate hyd rate:

(18) The XRDs were recorded using a Bruker AXS D4 ENDEAVOR (CuK.sub.α radiation, 40 kV, 40 mA) and the Rietveld measurements were carried out using the Topas 4.2 software from Bruker.

(19) For the XRD analysis, the hydrothermal C-S-H from the autoclave process was comminuted by means of a jaw crusher and opposed impingement mill to a particle size having a d(95) of ≤1 mm. 5 g of the powder were subsequently dried at 105° C. for 1 hour in a laboratory oven.

(20) For the XRD analysis, 2 g of the dried powder was in each case comminuted in an agate mortar until the sample could be brushed in its entirety through a sieve having a mesh opening of 36 μm.

(21) The sample for determining the proportion of the X-ray-amorphous phase was a homogeneously mixed powder which comprised the sample and a known amount of an internal crystalline standard. For these studies, from 15% by mass to 30% by mass of fluorite (CaF.sub.2) were triturated homogeneously with the sample (particle size <36 μm) in an agate mortar. The homogenized powder, which comprises fluorite as internal standard, was subsequently prepared and measured by means of “front loading”. A prerequisite for the use of fluorite as internal standard is that fluorite is not present in the original sample. It is necessary to select a standard having a mass attenuation coefficient (MAC) which is similar to that of the sample in order to minimize the X-ray adsorption contrast. The samples have an MAC for Cu K.sub.α radiation in the range from 75 to 80 cm.sup.2/g. For this reason, CaF.sub.2 having an MAC of 94.96 cm.sup.2/g was selected. The scientific literature recommends an amount of internal standard of about 20% by mass for an amorphous content in the range from 30 to 90% in the sample to be measured (Scrivener, Snellings, and Lothenbach. “Chapter 4. X-Ray Powder Diffraction Applied to Cement.” A Practical Guide to Microstructural Analysis of Cementitious Materials. CRC/Taylor & Francis Group, 2016. 107-176). The samples examined comprise from 10% by mass to 70% by mass of X-ray-amorphous or nanocrystalline phases having crystallite sizes of <5 nm, so that 15% by mass and 30% by mass of internal standard were used.

(22) The X-ray diffraction patterns (diffractograms) recorded by means of X-ray diffraction analysis were subsequently evaluated by means of Rietveld analysis using the software Topas 4.0. The Rietveld method is a standard method for evaluating diffraction patterns obtained by X-ray diffraction analysis of powder samples. The method is comprehensively described in, for example, G. Will (2006): Powder Diffraction—The Rietveld method and the two-stage method, Springer Verlag, and R. Young (1995): The Rietveld method, IUCr Monographs on Crystallography, vol. 5, Oxford University Press.

(23) The following structural data from the Inorganic Crystal Structure Database (ICSD) were used for the Rietveld analysis of the present samples:

(24) Tobermorite (mineral of the calcium silicate hydrates): ICSD number 152489

(25) Calcite: ICSD number 79674

(26) Quartz: ICSD number 174

(27) Portlandite: ICSD number 15471

(28) Fluorite: ICSD number 60368

(29) The phase content of the individual phases and also the crystallite size of the calcium silicate hydrate phase tobermorite were determined by means of Rietveld analysis. The crystallite size is indicated by the width at half height of the reflections of a phase and is determined in the refinement during the Rietveld analysis. The relationship between width at half height of a reflection in the diffraction pattern and the crystallite size is described, for example, in chapter 5.4.1, page 142 onwards, in R. Dinnebier, S. Billinge (2008): Powder Diffraction—Theory and Practice, RSC Publishing, and on page 113 in G. Will (2006): Powder Diffraction—The Rietveld method and the two-stage method, Springer Verlag, and also R. Young (1995): The Rietveld method, IUCr Monographs on Crystallography, vol. 5, Oxford University Press.

(30) The determination of the proportion of the X-ray-amorphous phase by means of an internal standard serves to quantify the absolute amount of the crystalline phases and the X-ray-amorphous phases and was carried out in accordance with the publication by I. Madsen, N. Scarlett and A. Kern, “Description and survey of methodologies for the determination of amorphous content via X-ray powder diffraction.” Zeitschrift für Kristallographie Crystalline Materials 226.12 (2011): 944-955. Here, the known proportion of the internal standard is set down during the Rietveld refinement and the other phases are related thereto. The difference between the sum of the crystalline phases (tobermorite, calcite, quartz, portlandite, fluorite) and 100% by mass corresponds to the proportion of X-ray-amorphous material in the sample.

(31) (iv) The charge density is determined by titration with poly-DADMAC (poly(diallyldimethylammonium chloride)) or sodium polyethylenesulfonate using a Mettler Toledo DL 28 titrator combined with a BTG Mütek particle charge detector.

(32) (v) To determine the viscosity, the suspensions were stored in a closed vessel at room temperature for 24 hours after the end of milling. The viscosity was subsequently determined on a Brookfield viscometer DV-II+ at 12 rpm using spindle 62.

(33) (vi) The determination of the weight average molecular weight of the polymeric dispersant was carried out by means of gel permeation chromatography (GPC) (column combinations: OH-Pak SB-G, OH-Pak SB 804 HQ and OH-Pak SB 802.5 HQ from Shodex, Japan; eluent: 80% by volume of aqueous solution of HCO.sub.2NH.sub.4 (0.05 mol/l) and 20% by volume of acetonitrile; injection volume 100 μl; flow rate 0.5 ml/min). Calibration for determining the average molar mass was carried out using linear poly(ethylene oxide) and polyethylene glycol standards.

(34) Preparation of Polymeric Dispersants:

(35) Polymers 1, 2 and 7

(36) 875 g of a 40% strength aqueous solution of polyethylene glycol hydroxybutyl monovinyl ether and NaOH (20%) are placed in a 1 liter four-neck flask provided with thermometer, reflux condensor and a connection for two feed streams. Details of the molar masses of the respective polyethylene glycol hydroxybutyl monovinyl ether may be found in table 2. The solution is then cooled to 20° C. Acrylic acid (99%) is then slowly added to the polyethylene glycol hydroxybutyl monovinyl ether solution in the initially charged flask. This decreases the pH to about 4-5. 0.5 g of iron(II) sulfate heptahydrate and 5 g of rongalite and mercaptoethanol are subsequently added. After these have been stirred in briefly, 3 g of 50% strength hydrogen peroxide are also introduced. The temperature increases from 20° C. to about 30° C.-65° C. as a result. The solution is subsequently stirred for 10 minutes before being neutralized with sodium hydroxide solution (20%). This gives a light-yellow, clear aqueous polymer solution having a solids content of about 40% by weight. The amounts of the chemicals used (NaOH, mercaptoethanol and acrylic acid) and the molar masses of the respective polyethylene glycol hydroxybutyl monovinyl ether (PEG-HBVE), weight average molar masses and the charge density of the polymer (number of mol of carboxylate and/or carboxyl groups/total molar mass of the PCE) (mol/(g/mol)) may be found in tables 1 and 2 below.

(37) TABLE-US-00001 TABLE 1 Details of the preparation of P1, P2 and P7 NaOH Mercaptoethanol Acrylic acid Polymer (20%) [g] [g] (99%) [g] P1 40 1.5 30.8 P2 10 1.7 42.4 P7 0 0.9 21.9

(38) TABLE-US-00002 TABLE 2 Overview of the structural parameters of the polymers Charge density M.sub.w Molar mass of PEG- Polymer (μeq/g) (g/mol) HBVE (g/mol) P1 1110 28 537 5800 P2 1488 28 659 3000 P7 811 35 665 5800

(39) Polymer P3

(40) The polymer P3 is a comb polymer and is based on the monomers maleic acid, acrylic acid and vinyloxybutylpolyethylene glycol—5800. The molar ratio of acrylic acid to maleic acid is 7. The molecular weight M.sub.W is 40 000 g/mol and was determined by GPC. The solids content is 45% by weight. The synthesis is, for example, described in EP 0894811. The charge density is 930 μeq/g.

(41) Polymer P4

(42) The polymer P4 is a condensate of the building blocks phenolPEG5000, phenoxyethanol phosphate and formaldehyde. The molecular weight M.sub.W is 25 730 g/mol. The polymer was prepared in a manner analogous to polymer 7 of WO 2015/091461 (table 1 and 2).

(43) Polymer P5

(44) The polymer P5 is a comb polymer polymerized from a hydroxyethyl methacrylate phosphate and an ester of methacrylic acid and methylpolyethylene glycol having a molecular weight of 5000 g/mol. The synthesis was carried out in a manner analogous to the preparation of P1 in WO 2014/026938. The molecular weight M.sub.W is 3660 g/mol. The solids content of the polymer solution is 29% by mass.

(45) Polymer P6

(46) The polymer 6 is a commercially available polyacrylate which has been partially neutralized with NaOH (degree of neutralization 80%). The average molecular weight M.sub.W is 5000-10 000 g/mol. The solids content of the polymer solution is 45% by mass.

(47) Hydrothermal calcium silicate hydrate (htCSH)

(48) htCSH1: Circolit, obtainable from Cirkel GmbH & Co. KG, Haltern am See.

(49) htCSH2:

(50) For the production of htCSH2, 153 kg of quartz flour (d(95) <63 μm, SiO.sub.2 content >95% by mass), 150 kg of quicklime (d(95) <90 μm, CaO content >90% by mass), 222 g of aluminum paste (water content=40%, d(50)=15 μm) and 340 kg of water were mixed. This suspension was allowed to stand for 3 hours at a temperature of 20° C. The material was subsequently maintained at 150° C. in an autoclave (about 5 bar) for 8 hours. The material was then cooled to room temperature and comminuted further by means of crushers and ball mills to a particle size d(95) <1 mm and d(50) <500 μm. The moisture content (determined by drying to constant weight at 105° C.) was 36.6% by mass.

(51) htCSH3:

(52) For the production of htCSH3, 100 kg of quartz flour (d(95) <63 μm, SiO.sub.2 content >95% by mass), 200 kg of quicklime (d(95) <90 μm, CaO content >90% by mass), 222 g of aluminum paste (water content=40%, d(50)=15 μm) and 410 kg of water were mixed. This suspension was allowed to stand for 3 hours at a temperature of 20° C. The material was subsequently maintained at 170° C. in an autoclave (about 8 bar) for 12 hours. The material was then cooled to room temperature and comminuted further by means of crushers and ball mills to a particle size d(95) <1 mm and d(50) <500 μm. The moisture content (determined by drying to constant weight at 105° C.) was 40.0% by mass.

(53) The starting materials used have the following properties (table 3):

(54) TABLE-US-00003 TABLE 3 Type htCSH1 htCSH2 htCSH3 Composition (in % by mass).sup.(1) C-S-H component C-S-H phase Xonotlite Tobermorite 14Å Tobermorite 14Å (C-S-H phase (C-S-H phase used as basis) used as basis) 84.5 14.6 23.3 Proportion of X-ray- 12.5. 51.1 60.6 amorphous material Crystalline foreign component Quartz n.d. 27.3 4.5 Portlandite n.d. 2.6 7.0 Calcite 3.0 2.7 4.6 Properties Crystallite size of 33 nm 3.6 nm 3.6 nm C-S-H phase Particle size distribution d(10) in μm 1 7 6 d(50) in μm 7 101 109 d(90) in μm 21 217 227 BET surface area 38 cm.sup.2/g 113 cm.sup.2/g 113 cm.sup.2/g Molar ratio of Ca/Si.sup.(3) 1.09* 0.89.sup.(2) 1.77.sup.(2) n.d.: not determinable (content is less than the detection limit) *determined from product data sheets .sup.(1)from XRD with subsequent Rietveld analysis .sup.(2)determined by means of X-ray fluorescence analysis (XRF) .sup.(3)from the total amount of the inorganic constituents of the hydrothermal CSH

(55) The wet milling of the hydrothermally produced calcium silicate hydrate was carried out by means of a shaking setup (shaker SK 300 from Fast & Fluid Management). The conditions for the individual wet millings are listed in table 4. For milling, 100 g of the suspension corresponding to the parameters in table 4 were introduced into 250 ml glass bottles filled with 500 g of milling beads composed of ZrO.sub.2 and having a diameter of 1 mm. Milling took place on setting 3 at an effective power I.sub.0 of 1281.1 W. Between the production of the suspensions (mixing of hydrothermal C-S-H, water and water-soluble polymer) and the actual wet milling with high shearing energy, the suspension was allowed to rest for 30 minutes without additional mechanical shearing action. After milling, the suspension was separated off from the milling beads by means of a sieve and in some cases rinsed with distilled water. The solids content of the suspension was subsequently determined by drying the suspension to constant weight at 60° C.

(56) For comparison with the prior art, 3 suspensions were produced by precipitation as described in WO 2010/026155 (pptCSH). These comprise amorphous CSH nuclei which have been stabilized by the polymer.

(57) TABLE-US-00004 TABLE 4 Polymer Solids Content of content content hydrothermal (solid) in after Milling Shearing Starting CSH (% by suspension milling .sup.(1) time energy Example material mass) Polymer (% by mass) (% by mass) (min) (kWh/t) S1* htCSH1 15 — — 15.26 180 604 S2* htCSH1 15 P4 2.5 17.67 180 604 S3* htCSH1 15 P1 2.5 17.63 180 604 S4* htCSH1 15 P3 2.5 17.69 180 604 S5* htCSH1 15 P6 2.5 17.48 180 604 S6* htCSH1 15 P5 2.5 17.73 180 604 S7 htCSH2 15 P1 2.5 11.22 180 604 S8 htCSH2 15 P1 3.5 12.38 180 604 S9 htCSH2 15 P1 7.5 15.79 180 604 S10 htCSH3 15 P1 2.5 11.56 180 604 S11 htCSH3 15 P1 3.5 12.70 180 604 S12 htCSH3 15 P1 7.5 16.27 180 604 S13 htCSH3 13.91 P7 2.8 15.22 20 67 S14 htCSH3 13.91 P7 2.8 16.72 60 201 S15 htCSH3 13.91 P7 2.8 16.86 120 402 S16* pptCSH — P7 2.8 17.92.sup.(2) 20 67 S17* pptCSH — P7 2.8 18.01.sup.(2) 60 201 S18* pptCSH — P7 2.8 18.22.sup.(2) 120 402 .sup.(1) The solids content of the suspension after milling was determined by drying 1 g of suspension to constant weight at 60° C. in a drying oven. .sup.(2)The samples were diluted with water to a solids content of 15% by mass before the viscosity measurement. *comparative example.

(58) For comparison with the prior art as setforth in WO 2010/026155, 3 suspensions (S16, S17, S18) and 3 suspensions according to the invention (S13, S14, S15) were produced, with 194 g of suspension being milled in the 250 ml bottles with an amount of milling media of 500 g in examples S13 to S18.

(59) For the production of S16 to S18, 15.5 g of Ca(OH).sub.2 (Merck, CAS 1305-62-0, purity>97%) and 12.1 g of SiO.sub.2 (Silica, fumed; CAS 112945-52-5, Sigma Aldrich, purity>99.9%) were mixed with water and polymer (see table 2 above) so that the total amount of the suspension was 194 g.

(60) To determine the shearing energy, the current in empty operation I.sub.0 (shaking motion without milling beads and material being milled) and the current in milling operation I.sub.P (shaking motion with glass bottles filled with milling beads and material being milled) were measured during operation of the shaker SK 300 by means of an AC multimeter clamp MX 350 from Metrix. The effective voltage was in both cases 230 V.

(61) The effective power I.sub.0 derived from the measured currents was 1281.1 W, while the effective power in milling operation I.sub.P for the milling of 400 g of suspension was 1361.6 W. This gives a required effective power P.sub.W of 201.25 W for the milling of 1 kg of suspension.

(62) The polymer content in the suspension is always based on the solids content of the polymer used.

(63) The suspensions were characterized in respect of the accelerating effect by means of heat flow calorimetry and in respect of viscosity by means of a Brookfield viscometer.

(64) Heat Flow Calorimetry:

(65) To determine the accelerating power of the accelerator suspensions, cement pastes comprising the accelerator suspensions were produced and the hydration kinetics thereof were measured by means of isothermal heat flow calorimetry. For this purpose, 100 g of portland cement (CEM I 52.5 R) were mixed with 40 g of water by means of an overhead stirrer for 90 seconds at 500 rpm. The suspension to be tested was added together with the mixing water to the cement, with the amount of mixing water then being corrected to take account of the amount of water comprised in the suspension, so that a water-cement value of 0.4 was set in each experiment. The added amounts of the suspension to be tested are shown in table 5.

(66) 6 g in each case of mortar or cement paste were then introduced into the measuring vessel and this was inserted into the calorimeter. The isothermal heat flow calorimetry was carried out using a TAMAir calorimeter from TA Instruments at 20° C.

(67) The cumulative heat of hydration after 6 hours was determined. Furthermore, for comparison of the samples, the maximum gradients in the heat flow between 2 and 8 hours were determined in each case and these were expressed as a ratio to the gradient of the comparator measurement (cement+water). The determination of the relative gradient was carried out as described in the publication by L. Nicoleau (2012) (L. Nicoleau: The acceleration of cement hydration by seeding: Influence of the cement mineralogy. Ibausil 18th International Building Material Conference in Weimar (2012), conference proceedings pages 1-0330-1-0337). The results of the calorimetric measurements are set forth in table 5 below:

(68) The results are shown in table 5.

(69) TABLE-US-00005 TABLE 5 Amount of Amount of HoH Viscosity suspension CSH starting after Acce- sus- added, based material 6 hours Accel- lerator pension on cement added, based [J/g of eration suspension (mPas) (% by mass) on cement cement] factor Without — 23.25 1.00 S1 >100 000 3.28 0.5% by mass 38.08 1.11 S1 >100 000 6.55 1.0% by mass 46.89 1.11 S2 85 3.30 0.5% by mass 41.52 1.30 S2 85 6.60 1.0% by mass 49.83 1.54 S3 30 3.31 0.5% by mass 42.07 1.39 S3 30 6.62 1.0% by mass 53.18 1.83 S4 20 3.30 0.5% by mass 41.82 1.37 S4 20 6.60 1.0% by mass 51.87 1.65 S5 3 3.34 0.5% by mass 33.41 1.35 S5 3 6.68 1.0% by mass 36.38 1.61 S6 7.5 3.29 0.5% by mass 33.83 1.20 S6 7.5 6.58 1.0% by mass 41.04 1.41 S7 10 5.20 0.5% by mass 48.32 1.85 S7 10 10.40 1.0% by mass 59.95 2.37 S8 20 4.98 0.5% by mass 44.66 1.87 S8 20 9.96 1.0% by mass 54.99 2.26 S9 30 4.75 0.5% by mass 33.32 1.50 S9 30 9.50 1.0% by mass 36.27 1.70 S10 15 5.05 0.5% by mass 57.74 2.13 S10 15 10.09 1.0% by mass 69.02 2.70 S11 15 4.85 0.5% by mass 55.01 2.22 S11 15 9.71 1.0% by mass 67.23 2.65 S12 20 4.61 0.5% by mass 41.01 2.26 S12 20 9.22 1.0% by mass 45.66 2.52 S13 18 9.86 1.25% by mass  51.30 1.42 S14 20 8.97 1.25% by mass  59.42 1.67 S15 35 8.90 1.25% by mass  65.31 1.79 S16 >100 000 8.37 1.25% by mass  64.91 1.65 S17 >100 000 8.33 1.25% by mass  68.95 1.80 S18 >100 000 8.23 1.25% by mass  66.58 1.69 HoH: cumulative heat of hydration from 0.5 hours of hydration onward.

(70) A viscosity of >100 000 means that the viscosity was not measurable because a solid gel has been formed.