Additives for cements comprising Ye'elimite

Abstract

A combination of retarders and regulators for hydration reaction of cementitious binders including clinkers based on Ye'elimite. Set retarders are calcium complexing agents, consisting of sugar acids, sugars, sugar alcohols, hydroxycarboxylic acids, phosphates, phosphonates, borates and amines. Regulator general formula (I) is ##STR00001##
where M is H, NH.sub.4 or chosen from monovalent or divalent metal of groups Ia, IIa, IIIa, Ib, IIb, IVb, VIb, VIIb or VIIIb of periodic table of elements, where M is a divalent metal, a second equivalent of RSO.sub.3 is present, and M is chosen from group consisting of H, NH.sub.4, Li, Na, K, MgX, CaX, or NiX with XRSO.sub.3, and R is chosen from H, NH.sub.2, OH or from hydrocarbon chain with 1-18 C atoms which may be substituted by N and/or O and/or which may be linear or branched and/or which contain one or more unsaturated bonds and/or cycloaliphatic and/or aromatic moieties.

Claims

1. A cementitious binder comprising a) at least one clinker based on Yeelimite, b) at least one set retarder S selected from the group consisting of sugar acids, sugars, sugar alcohols, hydroxycarboxylic acids, phosphates, phosphonates, borates, and amines, and c) at least one regulator R of the general formula (I) ##STR00007## where: M is H, NH.sub.4 or chosen from a monovalent or divalent metal of the groups Ia, IIa, IIIa, Ib, IIb, IVb, VIb, VIIb or VIIIb of the periodic table of elements, and, where M is a divalent metal, a second equivalent of RSO.sub.3 is present, and R is chosen from NH.sub.2, OH or from a hydrocarbon group with 1 C atom which may be substituted by N and/or O.

2. The cementitious binder according to claim 1, wherein the clinker contains 5-95 w %, based on the total dry weight of the clinker, of Yeelimite.

3. The cementitious binder according to claim 1, wherein the cementitious binder contains 5-99 w % of clinker, 0.01-2 w % of sodium gluconate, and 0.1-6 w % of the at least one regulator R of the general formula (I).

4. The cementitious binder according to claim 3, wherein the set retarder S is sodium gluconate, and in the general formula (I), M is H, and R is chosen from CH.sub.3 or NH.sub.2.

5. The cementitious binder according to claim 1, wherein M is selected from the group consisting of Li, Na, K, MgX, CaX, and NiX, where X is RSO.sub.3.

6. The cementitious binder according to claim 1, wherein the set retarder S is sodium gluconate, and in the general formula (I), M is H, and R is chosen from CH.sub.3 or NH.sub.2.

7. A cementitious mixture comprising the cementitious binder according to claim 1, the cementitious mixture further comprising a) water, b) optionally aggregates, and c) optionally one or more further additives selected from the group consisting of plasticizers, superplasticizers, shrinkage reducers, air entrainers, deaerating agents, stabilizers, viscosity modifiers, water reducers, accelerators, retarders, water resisting agents, strength enhancing additives, fibres, blowing agents, pigments, and steel passivating agents.

8. Shaped articles, obtainable by curing the cementitious binder according to claim 1 or a cementitious mixture comprising the cementitious binder.

9. A method for control of a hydration reaction at early age of a cement or a cementitious mixture, comprising a) providing a clinker or a cement or a cementitious mixture based on Yeelimite, b) providing at least one set retarder S selected from the group consisting of sugar acids, sugars, sugar alcohols, hydroxycarboxylic acids, phosphates, phosphonates, borates, and amines, c) providing at least one regulator R of the general formula (I), ##STR00008## where: M is H, NH.sub.4 or chosen from a monovalent or divalent metal of the groups Ia, IIa, IIIa, Ib, IIb, IVb, VIb, VIIb or VIIIb of the periodic table of elements, and, where M is a divalent metal, a second equivalent of RSO.sub.3 is present, and R is chosen from NH.sub.2, OH or from a hydrocarbon group with 1 C atom which may be substituted by N and/or O, d) providing water, e) optionally providing aggregates, f) optionally providing further additives, and g) mixing a) to f) in any given order.

10. The method according to claim 9, wherein the at least one set retarder S and the at least one regulator R are provided as individual components during any steps of the mixing.

11. The method according to claim 9, wherein the at least one set retarder S and the at least one regulator R are provided as a one component pre-mix during any step of the mixing.

Description

BRIEF DESCRIPTION OF FIGURES

(1) FIG. 1 shows cumulative heat flow curves on the examples of M-1, M-7, M-11;

(2) FIG. 2 shows heat flow curves on the examples of M-1, M-7, M-11;

(3) FIG. 3 shows cumulative heat flow curves on the examples of M-20, M-24, M-31; and

(4) FIG. 4 shows heat flow curves on the examples of M-20, M-24, M-31.

WORKING EXAMPLES

(5) The spread flow test, as a measure for workability of the cementitious mixture, was performed according to EN 12350-2. The spread flow test was performed on individual samples at defined points of time after mixing with mixing water. The respective times are given in below Tables 4 and 6.

(6) Compressive strength was measured according to EN 12390-1 to 12390-4 on prisms of size 4040160 mm.

(7) Heat flow curves were measured in an isothermal process as described in standard ASTM C1702-17. Examples M1-M19 were measured using a TAM AIR from TM Instruments. Examples M20-M33 were measured using an I-CAL 4000 from calmetrix. Cumulative heat flow curves were calculated from heat flow curves by integration using software default parameters.

(8) The open time is the time at the point of inflection of the cumulative heat flow curve. It was measured on the heat flow curve as the time where the heat flow curve starts to increase (see FIGS. 2 and 4; the initial peak pertains to the mixing process and is disregarded). The final setting time was measured on the cumulative heat flow curve and is the time when the increase in energy measured per 12 min becomes less than 0.1 J/g (see FIGS. 1 and 3). The plateau height is the total energy released from the time of mixing with mixing water until the final setting time is reached.

(9) The following Table 1 gives an overview of chemicals used. All chemicals were used as supplied unless otherwise noted.

(10) TABLE-US-00001 TABLE 1 chemicals used Chemical name Purity Source Boric acid 99.5% Sigma Aldrich Sulfamic acid 99.3% Sigma Aldrich Methanesulfonic acid 99% Sigma Aldrich Sodium gluconate 99% Sigma Aldrich PCE-type comb polymer, 31 w % in water Sika Schweiz AG acrylate/methallyl backbone, PEG side chain (2400 g/mol)

(11) TABLE-US-00002 TABLE 2 Cement composition (XRD, Rietveld refinement) Phase wt % Ye'elimite 29 Belite 46 Ferrite 4 Calcium sulfate Anhydrite 6 Ellestadite 4 Calcium aluminates 2 Calcite 1 Amorphous 8

Examples M1-17

(12) For the preparation of cementitious mixtures M1-M17 100 g of a cement with the composition shown in Table 2, 50 g of mixing water to yield a w/c ratio of 0.5, and admixture as given in below Table 3 were mixed on a Heidolph propeller mixer for 2 min at 1500 rpm.

(13) TABLE-US-00003 TABLE 3 Examples M1-M17 Example Additives M1* None M2* 0.05 g sodium gluconate M3* 0.5 g methanesulfonic acid M4* 0.5 g sulfamic acid M5* 0.2 g boric acid M6 0.05 g sodium gluconate, 2.0 g methanesulfonic acid M7 0.05 g sodium gluconate, 0.5 g methanesulfonic acid M8 0.05 g sodium gluconate, 1.0 g methanesulfonic acid M9 0.05 g sodium gluconate, 2.0 g sulfamic acid M10 0.05 g sodium gluconate, 0.5 g sulfamic acid M11* 0.1 g PCE M12* 0.1 g PCE, 0.05 g sodium gluconate M13 0.1 g PCE, 0.05 g sodium gluconate, 2.0 g sulfamic acid M14 0.05 g PCE, 0.1 g sodium gluconate, 1.0 g sulfamic acid M15 0.05 g PCE, 0.05 g sodium gluconate, 0.5 g sulfamic acid M16 0.05 g PCE, 0.025 g sodium gluconate, 0.25 g sulfamic acid M17 0.1 g sodium gluconate, 1.0 g sulfamic acid *comparative example not according to the invention

(14) TABLE-US-00004 TABLE 4 Results M1-M17 Plateau Spread flow Open Final height [mm] Exam- time setting plateau @ 0 @ 30 @ 60 ple [min] time [h] [J/g] min min min M1* 83 9.3 180.4 67 52 46 M2* 158 15.2 182.4 101 92 81 M3* 93 8.9 189.1 n.m. n.m. n.m. M4* 81 7.9 177.4 n.m. n.m. n.m. M5* 166 9.9 186.8 n.m. n.m. n.m. M6 142 10.9 218 80 82 77 M7 145 10.9 187.2 103 86 74 M8 164 11.5 200.8 n.m. n.m. n.m. M9 96 8.9 207.6 68 64 60 M10 134 10 179.7 93 72 65 M11* 200 12.3 175.8 145 143 148 M12* 386 dnc dnc 157 166 167 M13 168 10.4 196.4 152 169 163 M14 254 14.7 188.0 140 146 143 M15 166 11.7 180.4 n.m. n.m. n.m. M16 151 10.8 179.3 n.m. n.m. n.m. M17 215 12.1 185.3 95 88 75 *comparative example not according to the invention n.m.: not measured dnc: does not cure within 24 h

Examples M18-30

(15) For the preparation of cementitious mixtures M8-M30 265 g of CEN reference sand as described in EN 196-1 were added to 150 g of a cement with the composition shown in Table 2. The resulting dry mix was mixed in a Hobart mixer for 1 min. Then the amount of mixing water and additive as given in Table 5 was added to yield a w/c ratio as given in Table 5 and mixing was continued for 2 m.

(16) TABLE-US-00005 TABLE 5 Examples M18-M30 Example Additives Water w/c ratio M18* None 40 0.4 M19* 0.35 g boric acid 50 0.5 M20 0.05 g sodium gluconate, 0.5 g 50 0.5 sulfamic acid M21 0.1 g sodium gluconate, 0.7 g 50 0.5 sulfamic acid M22 0.05 g sodium gluconate, 0.25 g 50 0.5 sulfamic acid M23 0.025 g sodium gluconate, 0.25 g 50 0.5 sulfamic acid M24 0.1 g sodium gluconate, 1.0 g 50 0.5 sulfamic acid M25 0.15 g sodium gluconate, 1.5 g 50 0.5 sulfamic acid M26* 0.0775 g PCE 40 0.4 M27* 0.0775 g PCE, 0.35 g boric acid 40 0.4 M28 0.0775 g PCE, 0.1 g sodium gluconate, 40 0.4 1.0 g sulfamic acid M29 0.0775 g PCE, 0.05 g sodium gluconate, 40 0.4 0.5 g sulfamic acid M30 0.0775 g PCE, 0.05 g sodium gluconate, 40 0.4 0.5 g methanesulfonic acid *comparative example not according to the invention

(17) TABLE-US-00006 TABLE 6 Results M18-M30 Open Final Plateau Spread flow [mm] Exam- time setting height @ 0 @ 30 @ 60 ple [min] time [h] [J/g] min min min M18* 80 8.4 154.5 129 n.m. n.m. M19* 305 14.2 187.5 192 181 170 M20 143 10.5 178.7 n.m. n.m. n.m. M21 226 12.8 176.5 218 189 173 M22 149 11 175.0 210 172 159 M23 93 9.85 176.5 n.m. n.m. n.m. M24 226 12.9 189.7 n.m. n.m. n.m. M25 405 19.32 199.5 n.m. n.m. n.m. M26* 46 7.9 135 244 206 151 M27* 209 13 154.4 199 225 253 M28 265 13.8 179.6 246 255 240 M29 208 12.3 172 234 237 210 M30 209 13.4 166.6 n.m. n.m. n.m. *comparative example not according to the invention n.m.: not measured

(18) TABLE-US-00007 TABLE 7 Compressive strength results Compressive strength [MPa] Example @ 4 h @ 6 h @ 8 h @ 24 h M19* 2.1 19.2 M21 0.6 3.4 15.9 M22 3.9 10.6 17 M27* 29 M28 0.8 4.6 27.2 : not measurable *comparative example not according to the invention

(19) From the results presented in above Tables 3 to 7 it becomes evident that the non-inventive use of a regulator alone does not lead to an increase of open time. The non-inventive use of only a set retarder leads to significantly increased open times but also to strongly increased final setting times without any increase in plateau height. This is especially evident in case of non-inventive example M12, which did not show sufficient curing within 24 h.

(20) On the other hand, examples M6-M8, M10, M13-M17, M20-M22, M24, and M29, which all are according to the present invention, show an open time which is significantly increased and a final setting time which is only moderately increased when compared to the references M1, or M18, respectively. At the same time the plateau height of all these examples according to the present invention is the same or increased as compared to the respective reference. This increase in plateau height correlates with a higher compressive strength at early age.

(21) Inventive examples M9 and M23 show only moderate increase in open time but excellent increase in the plateau height together with a reduction or only slight increase of the final setting time when compared with the respective references. Finally, inventive examples M25, M28, and M30 show strongly increased open time over the reference. The final setting time is also increased in these cases, but this comes together with a strong increase in plateau height and thus with higher compressive strength at early age.

(22) Non-inventive examples M5, M19, and M27, which all use only boric acid and thus are all not according to the present invention can be seen as a benchmark comparison. From results presented above it becomes evident that examples according to the present invention lead to a more balanced control of hydration at early age as compared to these benchmark examples.

(23) From the spread flow measurement results as shown in above Tables 4 and 6 it becomes evident that examples according to the present invention do not have a significantly increase stickiness (which would be evident as a decreased initial spread flow) when compared to the respective references. Additionally, their spread flow retention is the same or better in all cases as compared to the respective references.