REGULATING CEMENTITIOUS MATERIAL FOR PROMOTING HYDRATION OF PORTLAND CEMENT

Abstract

A regulating cementitious material for promoting hydration of Portland cement is provided. The regulating cementitious material may include ingredients by weight as follows: ye'elimite, 27˜68 parts; anhydrite, 29˜68 parts; lithium nitrite, 2˜5 parts; ethylene glycol monoisopropanolamine, 0.14˜0.29 parts; triethanolamine acetate, 0.04˜0.09 parts; and polyglycerol, 0.04˜0.09 parts. An early strength of Portland cement can be improved through a cooperative hydration between minerals and an enhanced solubilization of a complexing agent.

Claims

1. A regulating cementitious material for promoting hydration of Portland cement, comprising ingredients in parts by weight as follows: ye'elimite, 27˜68 parts; anhydrite, 29˜68 parts; lithium nitrite, 2˜5 parts; ethylene glycol monoisopropanolamine, 0.14˜0.29 parts; triethanolamine acetate, 0.04˜0.09 parts; and polyglycerol, 0.04˜0.09 parts; wherein the ingredients in total are 100 parts by weight.

2. The regulating cementitious material according to claim 1, wherein the ye'elimite is prepared by: mixing powders of calcium carbonate (CaCO.sub.3), aluminum trioxide (Al.sub.2O.sub.3) and calcium sulfate (CSH.sub.2) according to a molar ratio of CaCO.sub.3:Al.sub.2O.sub.3:CSH.sub.2=3:3:1 to obtain a powder mixture, adding a powder of ye'elimite of 5% by weight of the powder mixture into the powder mixture as crystalline seeds, then sequentially mixing evenly, compacting, and calcining by raising a temperature to 1350° C. in 2 hours (h) and then keeping the temperature for 2 h, afterwards, cooling to a room temperature in 1 minute (min), and grinding until all passing through 200 mesh sieve; wherein a purity of the ye'elimite is greater than 97.5%.

3. The regulating cementitious material according to claim 1, wherein the anhydrite is prepared by keeping an anhydrite at 200° C. for 2 h in a high-temperature furnace.

4. The regulating cementitious material according to claim 1, wherein a molar ratio of the anhydrite to the ye'elimite is 11.

5. An application of the regulating cementitious material according to claim 1 in promoting hydration of Portland cement, wherein an addition amount of the regulating cementitious material is 10% by weight of the Portland cement.

6. A cement comprising: Portland cement and the regulating cementitious material according to claim 1; wherein an amount of the regulating cementitious material is 10% by weight of the Portland cement.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

[0026] The disclosure will be described in further detail below in conjunction with specific embodiments, but embodiments of the disclosure are not limited to these.

[0027] A ye'elimite mineral may be prepared as that: powders of calcium carbonate (CaCO.sub.3), aluminum oxide (Al.sub.2O.sub.3) and calcium sulfate (CSH.sub.2) are mixed according to a molar ratio of CaCO.sub.3:Al.sub.2O.sub.3:CSH.sub.2=3:3:1 to obtain a powder mixture, a powder of ye'elimite of 5 wt % of the powder mixture then is added into the powder mixture as crystalline seeds so that a resulting mixture is obtained; next, the resulting mixture is sequentially mixed evenly, compacted and calcinated by raising a temperature to 1350° C. within 2 h and then keeping/maintaining the temperature of 1350° C. for 2 h; and afterwards, the calcinated mixture is taken out and cooled to a room temperature within 1 minute (min), and then grinded until all passing through 200 mesh sieve.

[0028] An anhydrite may be prepared as that: keeping a raw anhydrite at 200° C. for 2 h for calcining in a high-temperature furnace.

[0029] Dosages of ingredients of a regulating cementitious material in various embodiments are as follows:

Embodiment 1

[0030] A regulating cementitious material for promoting rapid hydration of Portland cement may be composed of ingredients in parts by weight as follows:

[0031] ye'elimite, 67.02 parts;

[0032] anhydrite, 29.83 parts;

[0033] lithium nitrite, 2.91 parts;

[0034] ethylene glycol monoisopropanolamine, 0.14 parts;

[0035] triethanolamine acetate, 0.05 parts; and

[0036] polyglycerol, 0.05 parts.

[0037] Moreover, the ingredients in total are 100 parts by weight.

Embodiment 2

[0038] A regulating cementitious material for promoting the rapid hydration of Portland cement may be composed of ingredients in parts by weight as follows:

[0039] ye'elimite, 45.70 parts;

[0040] anhydrite, 50.92 parts;

[0041] lithium nitrite, 2.91 parts;

[0042] ethylene glycol monoisopropanolamine, 0.29 parts;

[0043] triethanolamine acetate, 0.09 parts; and

[0044] polyglycerol, 0.09 parts.

[0045] Moreover, the ingredients in total are 100 parts by weight.

Embodiment 3

[0046] A regulating cementitious material for promoting the rapid hydration of Portland cement may be composed of ingredients by weight as follows:

[0047] ye'elimite, 34.06 parts;

[0048] anhydrite, 60.82 parts;

[0049] lithium nitrite, 4.75 parts;

[0050] ethylene glycol monoisopropanolamine, 0.19 parts;

[0051] triethanolamine acetate, 0.09 parts; and

[0052] polyglycerol, 0.09 parts.

[0053] Moreover, the ingredients in total are 100 parts by weight.

Embodiment 4

[0054] A regulating cementitious material for promoting the rapid hydration of Portland cement may be composed of ingredients by weight as follows:

[0055] ye'elimite, 27.49 parts;

[0056] anhydrite, 67.30 parts;

[0057] lithium nitrite, 4.74 parts;

[0058] ethylene glycol monoisopropanolamine, 0.29 parts;

[0059] triethanolamine acetate, 0.09 parts; and

[0060] polyglycerol, 0.09 parts.

[0061] Moreover, the ingredients in total are 100 parts by weight.

[0062] In an application in promoting hydration of Portland cement, an addition amount of the regulating cementitious material may be 10 wt % of the Portland cement. According to the dosages of raw materials (i.e., ingredients), dry powders of raw materials in each of the above illustrated embodiments 1-4 are evenly mixed and placed in a cement mortar mixing pot/vessel. 1 part by weight of the regulating cementitious material and 3 parts by weight of Chinese ISO standard sand are taken, cement mortars in form of a 40 mm×40 mm×160 mm prism specimen prepared by a group of plastic cementitious sands made as per a water-cement ratio of 0.5 are placed in water and maintained to a specified age at 20° C., and then a strength test is carried out on a universal testing machine. The test shall be carried out in accordance with a testing method specified in GB/T17671-1999 (Method of testing cements-Determination of strength (ISO method)).

[0063] The dry powders of raw materials are evenly mixed according to predetermined dosages in each of the above illustrated embodiments 1-4 to obtain a dry powder mixture and then placed in a cement paste mixing pot/vessel, the water-cement ratio is determined to be 0.35, the dry powder mixture is stirred in a form of slow stirring (rotational speed of 140 revolutions per minute (r/min)) for 2 min first, then is stopped for 15 seconds (s), and afterwards is stirred in a form of quick/fast stirring (rotational speed of 280 r/min) for 2 min, 20 mm×20 mm×20 mm cement paste blocks are then formed in a six-piece mold and placed in water and maintained to a specified age at 20° C., and thereafter, a strength test is performed on a universal testing machine.

TABLE-US-00001 TABLE 1 test results of flexural strengths of cement mortars Blank Embodi- Embodi- Embodi- Embodi- Flexural control ment ment ment ment strengths group 1 2 3 4 1 d 3.64 4.73 4.31 4.15 5.12 3 d 4.95 5.79 5.64 5.98 7.32 7 d 7.21 8.62 8.14 9.23 10.15

TABLE-US-00002 TABLE 2 test results of compressive strengths of cement mortars Blank Embodi- Embodi- Embodi- Embodi- Compressive control ment ment ment ment strengths group 1 2 3 4 1 d 9.37 13.37 12.14 12.87 13.95 3 d 22.15 27.47 25.41 26.13 34.21 7 d 32.94 45.67 43.17 42.48 50.51

TABLE-US-00003 TABLE 3 test results of compressive strengths of cement pastes Blank Embodi- Embodi- Embodi- Embodi- Compressive control ment ment ment ment strengths group 1 2 3 4 1 d 12.37 21.37 19.14 20.87 24.95 3 d 35.15 43.47 41.41 46.13 49.21 7 d 55.94 68.67 63.17 63.48 73.51