PERFORMANCE ENHANCER FOR COMPOSITE CEMENTS

Abstract

Composition comprising a polyphosphate, an amine and an inorganic sulfate compound for enhancing the workability and/or the strength development of hydraulic binders comprising a cement and a high water demand supplementary cementitious material and/or a high water demand filler.

Claims

1. A composition comprising a) from 5 to 50% by weight, based on the total weight of the composition, of at least one polyphosphate, b) from 5 to 25% by weight of at least one amine of general formula (I) ##STR00002## wherein R.sup.1, R.sup.2 and R.sup.3 are independently from each other selected from H, C.sub.1-C.sub.6-alkyl and C.sub.1-C.sub.6-alkyl alkanol comprising 1, 2, or 3 OH groups, their salts, esters or mixtures thereof, with the proviso that at least one of R.sup.1, R.sup.2 and R.sup.3 is not H, and c) at least one inorganic sulfate compound.

2. The composition according to claim 1, wherein component a) is a linear or a cyclic polyphosphate with a number of phosphate units ranging from 2 to 100.

3. The composition according to claim 1, wherein component a) is selected from the group consisting of diphosphate, triphosphate, tetraphosphate, hexaphosphate, trimetaphosphate, hexmetaphosphate hexametaphosphate, and mixtures thereof.

4. The composition according to claim 1, wherein at least one of R.sup.1, R.sup.2 and R.sup.3 is C.sub.1-C.sub.6-alkanol.

5. The composition according to claim 4, wherein at least two of R.sup.1, R.sup.2 and R.sup.3 are C.sub.1-C.sub.4-alkanol.

6. The composition according to claim 1, wherein component c) is selected from the group consisting of ammonium sulfate, alkali sulfate, earth alkali sulfate, cement kiln dust, flue gas desulfurization residue, residue from sodium carbonate production, residue from alkaline chromite ore processing, and mixtures thereof.

7. The composition according to claim 1 comprising 10% by weight to 50% by weight component a), 5% by weight to 25% by weight component b), 35% by weight to 85% by weight component c), based on the total weight of the composition.

8. The composition according to claim 3, wherein at least one of R.sup.1, R.sup.2 and R.sup.3 is C.sub.1-C.sub.6-alkanol.

9. A hydraulic binder comprising a hydraulic cement, at least one supplementary cementitious material with high water demand and/or at least one filler with high water demand and a composition according to claim 1.

10. A hydraulic binder according to claim 9, wherein the binder comprises 0.05% by weight to 0.5% by weight component a) based on the total weight of the hydraulic binder, 0.02% by weight to 0.3% by weight component b), based on the total weight on the hydraulic binder, 0.05% by weight to 1.5% by weight component c), calculated as SO.sub.3, based on the total weight of the hydraulic binder.

11. The hydraulic binder according to claim 9, containing calcined clay and/or carbonated recycled concrete fines as the supplementary cementitious material and limestone as the filler.

12. A method for manufacturing a hydraulic binder comprising the steps i) providing a hydraulic cement and a supplementary cementitious material with high water demand and/or a filler with high water demand or providing a composite cement comprising a high water demand supplementary cementitious material and/or a high water demand filler, ii) providing the composition according to claim 1, iii) blending or intergrinding the composition with at least one of the supplementary cementitious material and/or filler and the cement and blending or intergrinding the supplementary cementitious material and/or filler and the cement to provide the hydraulic binder or blending or intergrinding the composition with the composite cement to provide the hydraulic binder.

13. The method according to claim 12, wherein the binder comprises from 10 to 70% by weight hydraulic cement, from 90 to 30% by weight supplementary cementitious material and/or filler and 0.1 to 3% by weight of the composition.

14. The method of claim 12, wherein the composition comprises 10% by weight to 50% by weight component a), 5% by weight to 25% by weight component b), 35% by weight to 85% by weight component c), based on the total weight of the composition.

15. A supplementary cementitious material comprising a high water demand calcined clay and/or carbonated recycled concrete fines and the composition according to claim 1.

16. The composition according to claim 8, wherein component c) is alkali sulfate, cement kiln dust, or a mixture thereof.

17. The binder according to claim 9, wherein the composition comprises 10% by weight to 50% by weight component a), 5% by weight to 25% by weight component b), 35% by weight to 85% by weight component c), based on the total weight of the composition.

18. The binder according to claim 10, wherein the composition comprises 10% by weight to 50% by weight component a), 5% by weight to 25% by weight component b), 35% by weight to 85% by weight component c), based on the total weight of the composition.

19. The binder according to claim 9, wherein component a) of the composition is a linear or cyclic polyphosphate with a number of phosphate units ranging from 2 to 100 and/or component c) is alkali sulfate, cement kiln dust, or a mixture thereof, and/or at least two of R.sup.1, R.sup.2 and R.sup.3 are C.sub.1-C.sub.4-alkanol.

20. The method according to claim 13, wherein component a) of the composition is a linear or cyclic polyphosphate with a number of phosphate units ranging from 2 to 100 and/or component c) is alkali sulfate, cement kiln dust, or a mixture thereof, and/or at least two of R.sup.1, R.sup.2 and R.sup.3 are C.sub.1-C.sub.4-alkanol.

Description

EXAMPLE 1

Procedure to Obtain the Presented Experimental Results:

[0106] A ternary cement containing 70 wt.-% Portland cement clinker and gypsum, 20 wt.-% calcined clay and 10 wt.-% limestone was made by blending the components together.

[0107] Standard mortar was made acc. to EN 196-1 consisting of 450 g of cement and 225 g of water. The mixture was first made without chemical additives (blank). Mortar spread flow was measured on the fresh mortar. Strength at 1 and 2 days was measured according to EN 196-1 on mortar prisms. The experiment was then repeated adding the compounds indicated in table 1 to the mixing water. Similarly, mortar spread flow was measured on the fresh mortars cast with the added additives. Strength at 1 and 2 days was additionally measured.

TABLE-US-00001 TABLE 1 Mixture Quantity of additive 1 (comparative) Cement (blank) 2 (comparative) Cement/(NaPO.sub.3).sub.6 (NaPO.sub.3).sub.6: 0.9 g 3 (comparative) Cement/(NaPO.sub.3).sub.6/TIPA*.sup.) (NaPO.sub.3).sub.6: 0.9 g TIPA: 0.45 g 4 (inventive) Cement/(NaPO.sub.3).sub.6/TIPA/Na.sub.2SO.sub.4 (NaPO.sub.3).sub.6: 0.9 g TIPA: 0.45 g Na.sub.2SO.sub.4: 2.25 g *.sup.)triisopropanolamine

[0108] The measured strength and flow are shown in FIG. 1. The columns represent the measured strengths and the triangles the measured flow. It is readily apparent that only mixture 4 shows both an increased compressive strength and an improved workability flow (mortar flow). While an addition of polyphosphate alone is able to improve flow in mixture 2 it reduces strength development. This cannot be remedied by adding an alkanolamine as seen for mixture 3.