CHEMICAL ADDITIVE FOR CALCIUM SULPHOALUMINATE-MODIFIED PORTLAND CEMENT

Abstract

A chemical additive for calcium sulphoaluminate-modified Portland cement comprises the following substances: (a) at least one alkanolamine borate; (b) at least one organic alcohol; and (c) at least one saccharide or a derivative thereof; and the substances and water are sequentially mixed and stirred to obtain the chemical additive for calcium sulphoaluminate-modified Portland cement. The chemical additive for calcium sulphoaluminate-modified Portland cement provided by the invention has better effects of regulating the setting time of the calcium sulphoaluminate-modified Portland cement and improving the 3d/28d strength increase rate, and also has a grinding aid effect when being added during grinding.

Claims

1. A chemical additive for calcium sulphoaluminate-modified Portland cement, comprising the following substances: (a) at least one alkanolamine borate; (b) at least one organic alcohol; and (c) at least one saccharide or a derivative thereof; wherein the substances and water are sequentially mixed and stirred to obtain the chemical additive for calcium sulphoaluminate-modified Portland cement.

2. The chemical additive for calcium sulphoaluminate-modified Portland cement of claim 1, wherein the mass ratio of the alkanolamine borate, the organic alcohol, the saccharide or the derivative thereof and the water is (15-60): (3-30): (3-25): (15-60).

3. The chemical additive for calcium sulphoaluminate-modified Portland cement of claim 1, wherein the mass ratio of the alkanolamine borate, the organic alcohol, the saccharide or the derivative thereof and the water is (25-50): (5-25): (3-20): (20-60).

4. The chemical additive for calcium sulphoaluminate-modified Portland cement of claim 1, wherein the alkanolamine borate is diethanolisopropanolamine borate, N,N-di(2-hydroxypropyl)-N-(hydroxyethyl) amine borate or triisopropanolamine borate.

5. The chemical additive for calcium sulphoaluminate-modified Portland cement of claim 1, wherein the organic alcohol is ethylene glycol, diethylene glycol, propylene glycol or glycerin.

6. The chemical additive for calcium sulphoaluminate-modified Portland cement of claim 1, wherein the saccharide or the derivative thereof is saccharose, glucose, fructose, high fructose corn syrup or cane molasses or a salt of the above-mentioned saccharide.

7. A process for using the chemical additive of claim 1 in calcium sulphoaluminate-modified Portland cement.

8. The process of claim 7, wherein the adding quantity of the chemical additive is 0.05-0.15% of the weight of the calcium sulphoaluminate-modified Portland cement.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] A clear and complete description of the technical solutions in the embodiments of the present invention will be given below. Apparently, the described embodiments are merely a part, but not all, of the embodiments of the present invention. The present invention can be better understood according to the following embodiments. However, those skilled in the art could easily understand that the specific material proportions, process conditions and results described in the embodiments are merely used for illustrating the present invention, rather than limiting the present invention described in detail in the claims. All of other embodiments, obtained by those of ordinary skill in the art based on the embodiments of the present invention without any inventive effort, fall into the protection scope of the present invention.

[0018] The present invention discloses a chemical additive for calcium sulphoaluminate-modified Portland cement, including the following substances added into the calcium sulphoaluminate-modified Portland cement (preferably the prepared chemical additive is added in the grinding process of the calcium sulphoaluminate-modified Portland cement): (a) at least one alkanolamine borate; (b) at least one organic alcohol; and (c) at least one saccharide or a derivative thereof. The raw materials and water are sequentially mixed and stirred to obtain the chemical additive for calcium sulphoaluminate-modified Portland cement. The chemical additive for calcium sulphoaluminate-modified Portland cement is simple in preparation and low in consumption, has better effects of regulating the setting time of the calcium sulphoaluminate-modified Portland cement and improving the 3d/28d strength increase rate, and also has a grinding aid effect when being added during grinding.

[0019] According to the present invention, the mass ratio of the alkanolamine borate, the organic alcohol, the saccharide or the derivative thereof and the water is (15-60): (3-30): (3-25): (15-60), more preferably (25-50): (5-25): (3-20): (20-60).

[0020] According to the present invention, the alkanolamine borate is any one of or a mixture of several of diethanolisopropanolamine (DEIPA) borate, N,N-di(2-hydroxypropyl)-N-(hydroxyethyl) amine (EDIPA) borate and triisopropanolamine (TIPA) borate. Boracic acid is an effective retarder of the calcium sulphoaluminate-modified Portland cement, but due to its low dissolubility, its dispersion and effect in cement mortar are limited, and thus its retarding effect for the calcium sulphoaluminate-modified Portland cement is influenced. The alkanolamine can reduce the surface energy of material particles, reduce particle aggregation and improve the grinding efficiency; the alkanolamine such as DEIPA, EDIPA, TIPA and the like is a known cement quality improver, can effectively improve the 28d and far age strength of the Portland cement, and is also beneficial to improving the 28d strength of the calcium sulphoaluminate-modified Portland cement. By adding the borate formed by esterification of the boracic acid and the alkanolamine into the calcium sulphoaluminate-modified Portland cement as an additive in the present invention, on the one hand effective dispersion of the alkanolamine borate in cement mortar is achieved, and on the other hand the borate is quickly hydrolyzed into boracic acid and alkanolamine in the alkaline mortar after water is added to cement, thereby realizing retardation and performance improvement of the calcium sulphoaluminate-modified Portland cement.

[0021] According to the present invention, the organic alcohol is one of or a mixture of several of ethylene glycol, diethylene glycol, propylene glycol and glycerin. The applicant discovers in studies that the organic alcohol is beneficial to improving the retarding effect of the boracic acid on the calcium sulphoaluminate-modified Portland cement.

[0022] According to the present invention, the saccharide or the derivative thereof is at least one of or a mixture of several of saccharose, glucose, fructose, high fructose corn syrup, cane molasses and a salt of the above-mentioned saccharide. The saccharide and the derivative thereof are conventional retarding components of the Portland cement. The applicant discovers in studies that the saccharide and the derivative thereof are also beneficial to improving the retarding effect of the boracic acid on the calcium sulphoaluminate-modified Portland cement.

[0023] The chemical additive for calcium sulphoaluminate-modified Portland cement prepared in the present invention is suitable for improving the setting time and the strength performance, particularly the 28d strength of the cement, and does not have negative influence on cement and concrete.

[0024] In order to further illustrate the technical solutions of the present invention, preferred implementations of the present invention will be described below in combination with the embodiments. However, it should be understood that these descriptions are merely used for further illustrating the features and the advantages of the present invention, rather than limiting the claims of the present invention.

Comparative Example 1

[0025] Calcium sulphoaluminate-modified Portland cement clinker is selected from Inner Mongolia JS Special Cement Co., Ltd., and dihydrate gypsum is selected from Nanjing ZL Cement Co., Ltd. The calcium sulphoaluminate-modified Portland cement clinker is pre-dried, 4 kg of materials (3.64 kg of the calcium sulphoaluminate-modified Portland cement clinker and 0.36 kg of the dihydrate gypsum) are weighed and ground in a 500 mm*500 mm standard laboratory grinder, various physical properties of the ground cement materials are tested by using a detection method with reference to JC/T 1099-2009 Calcium Sulphoaluminate-Modified Portland Cement.

Embodiment 1

[0026] 50 weight parts of diethanolisopropanolamine (DEIPA) borate, 15 weight parts of ethylene glycol, 10 weight parts of glycerin and 5 weight parts of sodium gluconate are successively added into 20 weight parts of water, and the mixture is stirred to obtain a chemical additive A.

[0027] According to the method of comparative example 1, 0.05 wt % of the chemical additive prepared in this embodiment is added to the materials for grinding in the laboratory grinder, and the measurement results of the ground materials are shown in table 1.

Embodiment 2

[0028] 35 weight parts of N,N-di(2-hydroxypropyl)-N-(hydroxyethyl) amine (EDIPA) borate, 12.5 weight parts of diethylene glycol, 10 weight parts of propylene glycol, 5 weight parts of saccharose and 5 weight parts of sodium gluconate are successively added into 32.5 weight parts of water, and the mixture is stirred to obtain a chemical additive B.

[0029] According to the method of comparative example 1, 0.1 wt % of the chemical additive prepared in this embodiment is added to the materials for grinding in the laboratory grinder, and the measurement results of the ground materials are shown in table 1.

TABLE-US-00001 TABLE 1 Standard Setting time/ consistency h:min Compressive Sieve residue/% water Initial Final strength/Mpa 80 45 μm consumption/% setting setting 1 d 3 d 28 d Comparative 2.4 14.6 26.1% 0:24 0:45 25.2 37.2 48.9 example 1 Embodiment 1.8 10.2 25.9% 0:45 1:26 25.6 39.8 54.3 1 Embodiment 1.2 9.8 26.1% 0:39 1:12 25.3 38.6 55.6 2

Embodiment 3

[0030] 15 weight parts of diethanolisopropanolamine (DEIPA) borate, 10 weight parts of N,N-di(2-hydroxypropyl)-N-(hydroxyethyl) amine (EDIPA) borate, 5 weight parts of glycerin and 15 weight parts of high fructose corn syrup (the solid content is 50%, and the ratio of fructose to glucose is 1:1) are successively added into 55 weight parts of water, and the mixture is stirred to obtain a chemical additive C.

[0031] The cement sample in comparative example 1 is selected, 0.15 wt % of the chemical additive C is added to the molded cement, then various physical properties are tested by using a detection method with reference to JC/T 1099-2009 Calcium Sulphoaluminate-Modified Portland Cement, and the measurement results are shown in table 2.

Embodiment 4

[0032] 18 weight parts of diethanolisopropanolamine (DEIPA) borate, 10 weight parts of N,N-di(2-hydroxypropyl)-N-(hydroxyethyl) amine (EDIPA) borate, 10 weight parts of triisopropanolamine borate, 10 weight parts of ethylene glycol, 8 weight parts of sodium gluconate and 4 weight parts of fructose are successively added into 40 weight parts of water, and the mixture is stirred to obtain a chemical additive D.

[0033] The cement sample in comparative example 1 is selected, 0.10 wt % of the chemical additive D is added to the molded cement, then various physical properties are tested by using a detection method with reference to JC/T 1099-2009 Calcium Sulphoaluminate-Modified Portland Cement, and the measurement results are shown in table 2.

TABLE-US-00002 TABLE 2 Standard consistency Setting time/h:min Compressive water Initial Final strength/Mpa consumption/% setting setting 1 d 3 d 28 d Comparative 26.1% 0:24 0:45 25.2 37.2 48.9 example 1 Embodiment 25.8% 0:49 1:23 23.6 38.8 56.7 3 Embodiment 26.0% 0:52 1:18 23.0 38.1 54.8 4

[0034] It can be seen from the above embodiments and the comparative example that the chemical additive for calcium sulphoaluminate-modified Portland cement provided by the present invention has better effects of regulating the setting time of the calcium sulphoaluminate-modified Portland cement and improving the 3d/28d strength increase rate, and also has a grinding aid effect when being added during grinding.

[0035] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Multiple modifications made to these embodiments would be obvious for those skilled in the art, and what is defined in the present invention generally can be achieved in other embodiments without departing from the spirit or scope of the present invention. Hence, the present invention would not be limited to these embodiments described herein, but conforms to the broadest scope consistent with the principle and the novelty of the disclosure herein.