Set control composition for cementitious systems

Abstract

A set control composition for cementitious systems comprises (a) an amine-glyoxylic acid condensate, and (b) at least one of (i) a borate source and (ii) a carbonate source. The carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 gL.sup.−1 or more, and organic carbonates. The set control composition improves workability of cementitious systems for prolonged periods of time without compromising early compressive strength. Due to the retarding action of the set control composition, the dosage of dispersant(s) necessary to obtain a desired flowability of the cementitious system can be reduced.

Claims

1. A set control composition for cementitious systems comprising a) an amine-glyoxylic acid condensate and b) at least one of (i) a borate source or (ii) a carbonate source, wherein the carbonate source is selected from the group consisting of inorganic carbonates having an aqueous solubility of 0.1 gL.sup.−1 or more, organic carbonates, and mixtures thereof.

2. The composition according to claim 1, wherein the set control composition is an aqueous system and has a pH higher than or equal to 6.5, or the set control composition is a powder and develops a pH higher than or equal to 6.5 when an aqueous system is formed from the powder by adding water to the powder.

3. The composition according to claim 1, wherein the amine-glyoxylic acid condensate is selected from the group consisting of a melamine-glyoxylic acid condensate, a urea-glyoxylic acid condensate, a melamine-urea-glyoxylic acid condensate, a polyacrylamide-glyoxylic acid condensate, and mixtures thereof.

4. The composition according to claim 1, wherein the inorganic carbonate having an aqueous solubility of 0.1 gL.sup.−1 or more is selected from the group consisting of potassium carbonate, sodium carbonate, lithium carbonate, magnesium carbonate, and mixtures thereof.

5. The composition according to claim 1, wherein the organic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, and mixtures thereof.

6. The composition according to claim 1, wherein the borate source is selected from the group consisting of borax, boric acid, sodium tetraborate, and mixtures thereof.

7. The composition according to claim 1 additionally comprising a component selected from the group consisting of: polycarboxylic acids or salts thereof whose milliequivalent number of carboxyl groups is 5.00 meq/g or higher, assuming all the carboxyl groups to be in unneutralized form; phosphonates which comprise two or three phosphonate groups and no carboxyl groups α-hydroxy carboxylic acids or salts thereof and mixtures thereof.

8. The composition according to claim 7, wherein the polycarboxylic acid is selected from the group consisting of phosphonoalkyl carboxylic acids, amino carboxylic acids, polymeric carboxylic acids, and mixtures thereof.

9. The composition according to claim 1 additionally comprising a dispersant.

10. The composition according to claim 9, wherein the dispersant is selected from the group consisting of: comb polymers having a carbon-containing backbone to which are attached pendant cement-anchoring groups and polyether side chains, non-ionic comb polymers having a carbon-containing backbone to which are attached pendant hydrolysable groups and polyether side chains, the hydrolysable groups upon hydrolysis releasing cement-anchoring groups, sulfonated melamine-formaldehyde condensates, lignosulfonates, sulfonated ketone-formaldehyde condensates, sulfonated naphthalene-formaldehyde condensates, phosphonate containing dispersants, cationic (co)polymers and mixtures thereof.

11. A construction material composition comprising at least one hydraulic binder and/or latent hydraulic binder and a set control composition according to claim 1.

12. The construction material composition according to claim 11, wherein the hydraulic binder is selected from the group consisting of Portland cement, calcium aluminate cement, sulfoaluminate cement, and mixtures thereof.

13. The construction material composition according to claim 11, wherein the latent hydraulic binder is blast furnace slag.

14. The construction material composition according to claim 11, wherein the hydraulic binder contains clinker and a weight percentage of sulfate with respect to the weight of clinker is from 4 to 14 weight %.

15. The composition according to claim 7, wherein the polycarboxylic acids or salts thereof whose milliequivalent number of carboxyl groups is 5.00 to 15.00 meq/g, assuming all the carboxyl groups to be in unneutralized form.

16. The composition according to claim 10, wherein the phosphate containing dispersants comprise at least one polyalkylene glycol unit.

17. A method of prolonging the open time of aqueous compositions containing at least one hydraulic binder and/or latent hydraulic binder comprising adding the set control composition of claim 1 to the aqueous compositions containing at least one hydraulic binder and/or latent hydraulic binder.

Description

EXAMPLES

(1) In the examples the following materials and methods were used:

(2) Dispersant 1: The dispersant is a PCE, more specifically a copolymer of 4-hydroxybutyl monovinyl ether ethoxylated with 64 moles of ethylene oxide in average and acrylic acid in a ratio of 1/10.

(3) Dispersant 2: The dispersant is a polycondensation product of poly(ethyleneoxide)monophenylether, phosphorylated phenoxyethanol and formaldehyde. It was synthesized according to Example 7 (Table 1) in WO 2015/091461.

(4) Dispersant 3: The dispersant is a polycondensation product of poly(ethyleneoxide)monophenylether, phosphorylated phenoxyethanol and formaldehyde. It was synthesized according to Example 1 (Table 1) in WO 2015/091461.

(5) PMAA: poly(methacrylic acid, sodium salt, average M.sub.w 4,000-6,000, 40 wt. % aqueous solution (manufacturer Aldrich).

(6) Polyacrylamide is a homopolymer of acrylamide obtained by radical polymerization. The molecular weight is 13500 g/mol (obtained by aqueous GPC as explained in detail below).

(7) Cublen P50: 2-Phosphonobutane-1,2,4-tricarboxylic acid

(8) Gel permeation chromatography method (GPC):

(9) Column combination: OH-Pak SB-G, OH-Pak SB 804 HQ and OH-Pak SB 802.5 HQ by Shodex, Japan; eluent: 80 Vol.-% aqueous solution of HCO.sub.2NH.sub.4 (0.05 mol/l) and 20 vol.-% methanol; injection volume 100 μl; flow rate 0.5 ml/min. The molecular weight calibration was performed with poly(acrylate) standards for the RI detector. Standards were purchased from PSS Polymer Standards Service, Germany.

(10) Amine-glyoxylic acid condensates (retarder Component (a)) were synthesized according the following recipes:

(11) Synthetic Procedure A

(12) Glyoxylic acid (amount is given according to table 1 as 100% glyoxylic acid) was added into a vessel and neutralized to the appropriate starting pH (table 1) with potassium hydroxide. All other ingredients were added. The mixture was heated to 80° C. and the water was separated with a water trap. After 7 h, the highly viscous substance was analyzed by gel permeation chromatography method (GPC) as described below.

(13) Synthetic Procedure B

(14) Glyoxylic acid (50% solution in water) (amount is given according to table 1 as 100% glyoxylic acid) was added into a vessel and neutralized to the appropriate starting pH (table 1) with potassium hydroxide. After adding all other components, the mixture was heated to 80° C. After 7 h, the highly viscous substance was analyzed by gel permeation chromatography method (GPC) as described below.

(15) Synthetic Procedure C

(16) Glyoxylic acid was used as a 50% solution in water (amount is given according to table 1 as 100% glyoxylic acid). It was added into a vessel and neutralized to the appropriate starting pH (table 1) with potassium hydroxide. After adding all other components, the mixture was stirred for 2 h. After 2 h, the highly viscous substance was analyzed by gel permeation chromatography method (GPC) as described below.

(17) TABLE-US-00001 TABLE 1 Glyoxylic Sulfanilic Guanidinium Mol. acid Melamine acid Urea Carbonate Start Synth. weight Temp. Retarder [g] [g] [g] [g] Polyacrylamide [g] pH proc. [g/mol] [° C.] 1 18.52 — — 10.0 — — 3.8 A 2300 75 2 13.64 10.50 7.35 5.0 — — 4 B 7000 75 3 14.81 — — 10.0 — — 5 B 1500 75 4 14.81 — — 10.0 — — 3.7 B 1000 75 5 12.34 — — 10.0 — — 3.8 B 7000 75 6 14.81 — — 10.0 — — 3.8 B 6000 25 7 14.81 — — 10.0 — — 5 B 6100 25 8 14.81 — — 10.0 — — 6 B 6300 25 9 14.81 — — 10.0 — — 7 B 6500 25 10 5.49 — — — — 10.0 3.6 B 750 25 11 5.49 — — — — 10.0 0 B 3000 25 12 12.34 — — 10.0 — — 5 B 3100 25 13 10.43 — — — 10.0 — 7 C 19000 25

(18) These amine-glyoxylic acid condensates were tested in a mortar along the lines of DIN EN 1015.

(19) The cement mortar was compounded with a sand/cement ration of s/c=2 (CEM I 52.5 N). The sand was a mixture of 70% norm sand and 30% quartz sand. The water/cement weight ratio was 0.42. The amount of additives added are summarized in table 2. The dosage of the dispersant was adjusted to achieve a spread of 24±1 cm. The spread was determined using a Haegerman cone. Immediately after mixing the cone is completely filled with applying 15 strokes after lifting the cone, and the spread of the mortar measured.

(20) The cement mortar was prepared in a 5 L RILEM mixer. The mixer was charged with cement and sand. Thereafter, mixing was started at low speed (140 rpm). After 30 s mixing water and the therein dissolved additives was uniformly added to the mixture. The mixing speed was then increased (285 rpm) and continued for 90 s.

(21) The “time until spread <22 cm” was determined as follows: Since in retarded cement systems, set and loss of flowability are closely connected, an initial set time was determined with a Vicat apparatus according to DIN EN 196-3. Spread testing was started 15 minutes before the predetermined initial set time and was repeated every 10 minutes until the spread was <22 cm. During the initial 20 minutes, the spread test was repeated every 5 minutes.

(22) The results of the mortar testing are summarized in tables 2 and 2.1.

(23) Table 2 shows the synergistic effects of components (a) and (b) in the absence of c).

(24) TABLE-US-00002 TABLE 2 Retarder Retarder Component Component Dispersant (a) (b) No. [% bwoc] [% bwoc] [% bwoc] 33* 1 0.125 — — Modified 0.05 starch 34* 1 0.135 — — Sodium 0.05 Gluconate 35* 1 0.255 — — — — 50* 1 0.29 7 0.19 — — 44* 1 0.29 — — Sodium 0.19 Carbonate 45* 1 0.29 — — Propylene 0.19 Carbonate 41  1 0.07 1 0.19 Sodium 0.19 Carbonate 51  1 0.07 7 0.19 Propylene 0.19 Carbonate *Denotes a comparative example.

(25) TABLE-US-00003 TABLE 2.1 Time until spread < 22 cm Final set 4 h strength 24 h strength Exp. No. [min] [min] [MPa] [MPa] 33* 10 305 nm 19.1 34* 10 347 nm 20.3 35* 10 347 nm 20.4 50* 10 312 nm 9 44* 10 314 nm 5.5 45* 10 301 nm 5.5 41 15 54 1.0 18.1 51 30 100 1.0 4.5 *denotes a comparative example. nm denotes that the data were not measurable (too small).

(26) This set of experiments shows that only the combination of component a) and component b) (41 and 51) shows sufficient open time combined with measurable strength after 4 h and a significant increase in the 24 h strength.

(27) Component a) (50*) and component b) (44*, 45*) alone give no measurable strength after 4 h and reduce the 24 h strength tremendously in comparison to the examples according to the invention (41 and 51).

(28) Table 3 shows the synergistic effect of components (a), (b) and (c).

(29) TABLE-US-00004 TABLE 3 Retarder Retarder Component Component Component Dispersant (a) (b) (c) No. [% bwoc] [% bwoc] [% bwoc] [% bwoc] 51 1 0.07 7 0.19 Propylene 0.19 — — Carbonate 10 1 0.07 7 0.19 Propylene 0.19 PMAA 0.125 Carbonate  52* 1 0.29 7 0.19 — — PMMA 0.125  36* 1 0.29 — — Sodium 0.19 PMAA 0.125 Carbonate  37* 1 0.29 — — Propylene 0.19 PMAA 0.125 Carbonate 39 1 0.07 1 0.19 Sodium 0.19 Sodium 0.125 Carbonate Gluconate 40 1 0.07 1 0.19 Sodium 0.19 Sodium 0.125 Carbonate Tartrate  1 1 0.07 1 0.19 Propylene 0.25 Cublen 0.125 Carbonate P50 41 1 0.07 1 0.19 Sodium 0.19 — — Carbonate  8* 1 0.07 6 0.19 Citric acid 0.19 PMAA 0.125

(30) TABLE-US-00005 TABLE 3.1 Time until spread < 22 cm Final set 4 h strength 24 h strength Exp. No. [min] [min] [MPa] [MPa] 51 30 100 1 4.5 10 113 163 2.1 7.6 52* 30 360 nm 2 36* 10 83 nm 19.6 37* 10 352 nm 20.1 39 210 398 1.0 6.0 40 60 78 4 12.0  1 140 145 0.5 5.3 41 15 54 1.0 18.1  8* 10 19 2 4.6

(31) This set of experiments shows that the addition of component c) to a mixture of component a) and b) (examples 10, 39, 40, 1) increases the open time strongly under preservation of 4 h strength. If one of a) or b) is missing, no 4 h strength can be measured (comparative examples 52*, 36* and 37*).

(32) Tables 4 and 4.1 show the performance of different retarder components a) in the presence of b) and c).

(33) TABLE-US-00006 TABLE 4 Retarder Retarder Component Dispersant Comp. (a) Comp. (b) (c) No. [% bwoc] [% bwoc] [% bwoc] [% bwoc] 2 1 0.07 1 0.19 Propylene 0.19 PMAA 0.125 Carbonate 3 1 0.07 2 0.19 Propylene 0.19 PMAA 0.125 Carbonate 4 1 0.07 3 0.19 Propylene 0.19 PMAA 0.125 Carbonate 5 1 0.07 4 0.19 Propylene 0.19 PMAA 0.125 Carbonate 6 1 0.07 5 0.19 Propylene 0.19 PMAA 0.125 Carbonate 9 1 0.07 6 0.19 Propylene 0.19 PMAA 0.125 Carbonate 10 1 0.07 7 0.19 Propylene 0.19 PMAA 0.125 Carbonate 23 1 0.07 10 0.19 Propylene 0.19 PMAA 0.125 Carbonate 24 1 0.07 11 0.19 Propylene 0.19 PMAA 0.125 Carbonate 25 1 0.07 12 0.19 Propylene 0.19 PMAA 0.125 Carbonate 42 1 0.14 13 0.3 Sodium 0.19 PMAA 0.125 Carbonate

(34) TABLE-US-00007 TABLE 4.1 Time until spread < 22 cm Final set 4 h strength 24 h strength Exp. No. [min] [min] [MPa] [MPa]  2 100 155 0.7 6.3  3 109 155 0.7 3.9  4 98 134 0.6 5.2  5 103 125 0.7 5.5  6 110 139 0.8 3.0  9 108 142 0.7 8.4 10 113 163 2.1 7.6 23 100 120 2.5 15.8 24 71 117 2.4 16.0 25 130 173 0.8 8.3 42 60 135 1.8 14.0

(35) It can be seen that the open time as well as the 4 h strength values are throughout good.

(36) Tables 5 and 5.1 show the influence of the carbonate source.

(37) TABLE-US-00008 TABLE 5 Retarder Retarder Component Dispersant Comp. (a) Comp. (b) (c) No. [% bwoc] [% bwoc] [% bwoc] [% bwoc] 10 1 0.07 7 0.19 Propylene 0.19 PMAA 0.125 Carbonate 11 1 0.07 7 0.19 Sodium 0.19 PMAA 0.125 Carbonate 12 1 0.07 7 0.47 Magnesium 0.03 PMAA 0.125 Carbonate 13 1 0.07 7 0.30 Sodium 0.30 PMAA 0.125 Carbonate 14 1 0.07 7 0.19 Sodium 0.30 PMAA 0.125 Carbonate 15 1 0.055 7 0.19 Sodium 0.30 PMAA 0.125 Carbonate 16 1 0.045 7 0.19 Sodium 0.30 PMAA 0.125 Carbonate 17 1 0.07 7 0.30 Sodium 0.19 PMAA 0.125 Carbonate 18 1 0.07 7 0.47 Magnesium 0.03 PMAA 0.125 carbonate 19 1 0.07 7 0.47 Magnesium 0.03 PMAA 0.125 carbonate 20 1 0.07 7 0.475 Magnesium 0.025 PMAA 0.125 carbonate 21 1 0.07 7 0.44 Magnesium 0.06 PMAA 0.125 carbonate 22 1 0.07 7 0.88 Magnesium 0.12 PMAA 0.125 carbonate 27 1 0.07 7 0.30 Propylene 0.30 PMAA 0.125 Carbonate 28 1 0.07 7 0.40 Propylene 0.40 PMAA 0.125 Carbonate 29 1 0.07 7 0.50 Propylene 0.50 PMAA 0.125 Carbonate 30 3 0.25 7 0.19 Propylene 0.19 PMAA 0.125 Carbonate 31 2 0.08 7 0.19 Propylene 0.19 PMAA 0.125 Carbonate 32 7 0.19 Sodium 0.19 PMAA 0.350 Carbonate  36* 1 0.29 — — Sodium 0.19 PMAA 0.125 Carbonate  37* 1 0.29 — — Propylene 0.19 PMAA 0.125 Carbonate 38 1 0.07 1 0.25 Sodium 0.25 PMAA 0.125 Borate 39 1 0.07 1 0.19 Sodium 0.19 Sodium 0.125 Carbonate Gluconate 40 1 0.07 1 0.19 Sodium 0.19 Sodium 0.125 Carbonate Tartrate 41 1 0.07 1 0.19 Sodium 0.19 — — Carbonate  2 1 0.07 1 0.19 Propylene 0.19 PMAA 0.125 Carbonate  53* 1 0.07 7 0.19 Calcium 0.19 PMAA 0.125 Carbonate

(38) TABLE-US-00009 TABLE 5.1 Time until spread < 22 cm Final set 4 h strength 24 h strength Exp No [min] [min] [MPa] [MPa] 10 113 163 2.1 7.6 11 40 54 2 14.5 12 40 55 0.7 9.3 13 120 171 3 15.7 14 90 117 1.5 16.7 15 50 71 1.6 16.8 16 50 69 2.5 16.5 17 60 108 1.6 16.2 18 55 65 0.6 10.9 19 46 54 0.6 9.3 20 67 81 0.6 10.0 21 41 50 0.6 9.7 22 98 118 2.31 13.3 27 121 172 2.5 6.8 28 134 197 1.2 5.2 29 142 201 1.0 4.6 30 101 122 0.8 4.7 31 95 117 1.8 16.1 32 120 210 0.6 4.0 36* 10 83 nm 19.6 37* 10 352 nm 20.1 38 50 72 0.7 11.6 39 210 398 1.0 6.0 40 60 78 4 12.0 41 15 54 1.0 18.1  2 100 155 0.7 6.3 53* Not adjustable >1 d 0 0

(39) This set of experiments shows the broad applicability of inorganic carbonates.

(40) Table 6 shows the influence of the pH on the performance of the set control compositions. The pH was adjusted with H.sub.2SO.sub.4.

(41) TABLE-US-00010 TABLE 6 Retarder Retarder Component Component Component Dispersant (a) (b) (c) No pH [% bwoc] [% bwoc] [% bwoc] [% bwoc] 11 11.2 1 0.07 7 0.19 Sodium 0.19 PMAA 0.125 Carbonate 46 6 1 0.07 7 0.19 Sodium 0.19 PMAA 0.125 Carbonate 47 7 1 0.07 7 0.19 Sodium 0.19 PMAA 0.125 Carbonate 48 8 1 0.07 7 0.19 Sodium 0.19 PMAA 0.125 Carbonate

(42) TABLE-US-00011 TABLE 6.1 Time until spread < 22 cm Final set 4 h strength 24 h strength Exp. No. [min] [min] [MPa] [MPa] 11 40 54 2 14.5 46 10 45 nm 2.8 47 30 48 0.4 4 48 35 52 0.7 7.1

(43) This set of experiments show the importance of the pH of the formulation on the performance in mortar. The performance increases with a higher pH. For the example 46 it is supposed that at a pH as low as 6, the carbonate is no more stable and the carbonate may have partially disappeared from the composition in the form of carbon dioxide. nm=not measurable (below detection limit)

(44) The inventive examples according to tables 1 to 6 exhibit a fairly high time until spread <22 cm which is indicative of a prolonged open time. Comparative examples 8*, and 33* through 37* lacking either a borate or carbonate source (example 8*) or the amine-glyoxylic acid condensate (examples 33* through 37*) show an insufficient time until spread <22 cm.

(45) The cementitious mortar was prepared in a 5 L RILEM mixer. The mixer was charged with cement, aggregate and sand. Thereafter, mixing was started at low speed (140 rpm). After 30 s mixing water and the therein dissolved additives were uniformly added to the mixture. The mixing speed was then increased (285 rpm) and continued for 90 s.

(46) The slump was determined using a cone with height of 15 cm and an internal diameter at the top of 5 cm and 10 cm at the bottom. The cone was completely filled immediately after mixing, the cone was lifted, and the slump of the mortar measured.

(47) TABLE-US-00012 TABLE 7 Fillers Calcit MS-12 Pa.1  134.43 g CEM I 42.5 R Karlstadt 1075.44 g Quarz 0.1/0.3  250.22 g Quarz 0.3/1  200.17 g Sand 0/4 2175.13 g Crushed gravel 2/5  565.00 g

(48) In another experiment the influence of calcium sulfate is demonstrated (tables 8 and 8.1).

(49) TABLE-US-00013 TABLE 8 Dispersant Retarder Na-Gluco- Anhydride 1 7 NaHCO3 nate (CaSO.sub.4) 0.16 — — — — 0.10% 0.30% 0.475% 0.10% — 0.1 0.3 0.475% 0.10% 10%

(50) TABLE-US-00014 TABLE 8.1 Slump [cm] Compressive strength [MPa] 5 min 30 min 45 min 2 h 5 h 24 h 12.2 8.1 7.5 0 0 25.2 11.6 10.8 10.5 2.1 2.3 7.2 11.6 12 7.5 4.5 5.0 14.0

(51) This set of experiments shows the influence of additional amounts of a sulfate source. The very early strength profile is improved by 2 to 3 MPa at 2 h and 5 h respectively. The 24 strength is improved by 100%.

(52) The effect of the invented additive composition in construction materials composition based on latent-hydraulic binder is demonstrated in a mortar experiment with the following recipe (table 9). Ground granulated blast furnace slag (GGBFS) is used as latent-hydraulic binder. Fly ash is added as pozzolanic binder component and alkaline activator (mixture of NaOH and Na.sub.2SiO.sub.3) is added as a typical hardening accelerator for non-hydraulic binders. The alkaline activator (NaOH solution and Na.sub.2SiO.sub.3) is dissolved in the mixing water.

(53) TABLE-US-00015 TABLE 9 GGBFS   480 g Fly Ash (Class F)   120 g Normsand  1350 g NaOH (20 wt.-% solution)    3 g Na.sub.2SiO.sub.3  1.5 g Water   260 g

(54) The mortar was prepared in a 5 L RILEM mixer. The mixer was charged with the powder binder components and sand. Thereafter, mixing was started at low speed (140 rpm). After 30 s mixing water and the therein dissolved alkaline activator and additives were uniformly added to the mixture. The mixing speed was then increased (285 rpm) and continued for 90 s.

(55) The spread was determined using a Haegerman cone. The cone is completely filled with applying 15 strokes immediately after lifting the cone and the spread of the mortar measured (table 9.1).

(56) TABLE-US-00016 TABLE 9.1 Retarder 7 Na.sub.2CO.sub.3 Spread after Spread after (% bwoGGBFS) (% bwoGGBFS) 5 min (cm) 30 min (cm) 0 5.42 19 17 5.42 0 18 17 1.25 4.17 22 22

(57) There is a clear synergistic effect between component A (Retarder 7) and component B (sodium carbonate), as claimed by the invention, on the flowability retention of construction materials composition based on latent-hydraulic binder.