Liquid alkali-free accelerator for sprayed concrete and preparation method thereof
阅读说明：本技术 一种喷射混凝土用液体无碱速凝剂及其制备方法 (Liquid alkali-free accelerator for sprayed concrete and preparation method thereof ) 是由 蒋禹 邓磊 陈文红 罗小峰 蒋卓君 于 2019-12-13 设计创作，主要内容包括：本发明公开了一种喷射混凝土用液体无碱速凝剂及其制备方法,所述速凝剂包括下列重量份数的组分：无机含铝物质20～50重量份、无机酸5～10重量份、醇酸类物质5～8重量份、酸性稳定剂2～5重量份、增溶稳定剂2～6重量份、增粘剂1～3重量份和水30～55重量份。与现有速凝剂相比,本发明的液体无碱速凝剂不会出现分层现象,保质期延长、凝结时间缩短、抗压强度显著增加,而且使用本发明的速凝剂以后,喷射混凝土在喷射过程中几乎无粉尘,环境污染小,回弹率在8％以下,极大地减少了喷射过程中造成的经济损失。(The invention discloses a liquid alkali-free accelerator for sprayed concrete and a preparation method thereof, wherein the accelerator comprises the following components in parts by weight: 20-50 parts of inorganic aluminum-containing substance, 5-10 parts of inorganic acid, 5-8 parts of alkyd substance, 2-5 parts of acidic stabilizer, 2-6 parts of solubilizing stabilizer, 1-3 parts of tackifier and 30-55 parts of water. Compared with the existing accelerator, the liquid alkali-free accelerator provided by the invention has the advantages that the layering phenomenon cannot occur, the quality guarantee period is prolonged, the setting time is shortened, and the compressive strength is obviously increased.)
1. The liquid alkali-free accelerator for sprayed concrete is characterized by comprising the following components in parts by weight: 20-50 parts of inorganic aluminum-containing substance, 5-10 parts of inorganic acid, 5-8 parts of alkyd substance, 2-5 parts of acidic stabilizer, 2-6 parts of solubilizing stabilizer, 1-3 parts of tackifier and 30-55 parts of water.
2. The accelerator according to claim 1, further comprising 2-5 parts by weight of an unsaturated organic amine early strength agent.
3. The accelerator according to claim 2, wherein the inorganic aluminum-containing substance is selected from the group consisting of aluminum sulfate, aluminum nitrate, aluminum phosphate, aluminum fluoride, aluminum triphosphate, and combinations thereof.
4. The accelerator according to claim 2, wherein the inorganic acid is selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, silicic acid, fluoroboric acid, meta-aluminate, and combinations thereof.
5. The accelerator according to claim 2, wherein the alkyd-type material is an alkyd or thiolate compound having the following structural formula:
wherein R is H, straight chain or branched chain C1-C5An alkyl group.
6. The accelerator according to claim 2, wherein the acidic stabilizer is selected from the group consisting of hydroxyethylidene diphosphate, sorbic acid, fumaric acid, itaconic acid, sulfamic acid, and combinations thereof.
7. The accelerator of claim 2, wherein the solubilizing stabilizer is selected from the group consisting of stearyl alcohol, sucrose fatty acid esters, hydrogenated castor oil, stearic acid, bis fatty acid ethyl hydroxyethyl methyl ammonium methyl sulfate, octylphenol polyoxyethylene ether, cocamidopropyl betaine, ethylene glycol distearate, sorbitan monooleate, glycerol monostearate, silica, and combinations thereof.
8. The accelerator according to claim 2, wherein the viscosity increasing agent is selected from the group consisting of anionic polyacrylamide, carrageenan, sesbania gum, sodium polyacrylate, welan gum, guar gum, sodium alginate, polyacrylamide emulsion, polyamide wax, microcrystalline cellulose, and combinations thereof.
9. The accelerator according to claim 2, wherein the unsaturated organic amine early strength agent is a β -diketoimine compound having the following structural formula:
wherein Ar is
R2、R3、R4、R5、R6Are identical or different and are each independently H, straight-chain or branched C1-C5Alkoxy, -OH or-NH2。
10. The accelerator according to claim 9, wherein R is2is-NH2And/or R6is-NH2The early-strengthening effect is best.
11. The method for producing an accelerator according to any one of claims 1 to 10, characterized by comprising the steps of:
1) preparing a mother solution: adding the water, the inorganic aluminum-containing substance and the inorganic acid in parts by weight into a reaction kettle, heating to 90-110 ℃, and stirring for 0.5-2 hours to fully dissolve the inorganic aluminum-containing substance to obtain mother liquor;
2) preparing a semi-finished product: cooling the mother liquor obtained in the step 1) to 50-60 ℃, then adding the alkyd substances, the acidic stabilizer, the solubilizing stabilizer, the tackifier and the unsaturated organic amine early strength agent in parts by weight, and stirring for 0.5-5 hours to fully and uniformly mix the components to obtain a semi-finished product of the alkali-free accelerator;
3) and (3) preparing a finished product: stirring the semi-finished product obtained in the step 2) for 15-60 min by using a high-speed stirrer at the rotating speed of 1500-4000 r/min to obtain the finished product of the alkali-free accelerator.
12. An early strength agent, wherein the early strength agent is a beta-diketoimine compound having the following structural formula:
wherein Ar is
R2、R3、R4、R5、R6Are identical or different and are each independently H, straight-chain or branched C1-C5Alkoxy, -OH or-NH2。
13. The early strength agent according to claim 12, wherein R is2is-NH2And/or R6is-NH2The early-strengthening effect is best.
Technical Field
The invention belongs to the technical field of building materials, and particularly relates to a liquid accelerator for sprayed concrete and a preparation method thereof.
Background
Before 2017, dry spraying technology is used for spraying concrete in most areas in China, and since the dry powder accelerator is used for dry spraying and is a high-alkalinity accelerator, the later-stage concrete strength loss reaches more than 50%, and the engineering potential safety hazard is large; the rebound amount in the dry spraying process is too large and reaches 25-30 percent, so that concrete materials are wasted, and economic loss is caused; and excessive dust in the spraying process not only pollutes the environment, but also seriously harms the health of site constructors. In view of the defects, after 2017, the use of a dry spraying technology is forbidden by the country, so that the wet spraying technology is started, a liquid alkaline accelerating agent or a liquid alkali-free accelerating agent is used in the wet spraying process, the harm is obviously reduced, but the liquid alkaline accelerating agent is a high-alkaline substance and can react with concrete to generate alkali aggregate, so that the later strength of sprayed concrete can only reach 65-70% of the designed strength, the durability of the concrete is reduced, and workers can be burnt by the high-alkaline liquid accelerating agent in the concrete spraying process to generate a peeling phenomenon, so that the workers are greatly injured.
The dry powder accelerator and the alkaline liquid accelerator are damaged in different degrees in the using process, and the alkali-free liquid accelerator is required to be used in railway tunnel engineering aiming at the problems. And the research on the liquid alkali-free accelerator in China is relatively late, and the liquid alkali-free accelerator with indexes reaching GB/T35159-2017 in the market is extremely rare.
Based on market demands, the inventor researches and develops the liquid alkali-free accelerator for sprayed concrete, and all indexes of the accelerator can meet the requirements of GB/T35159 and 2017, so that the accelerator has a remarkable application prospect.
Disclosure of Invention
Aiming at various problems of the conventional accelerator, the invention aims to provide a liquid alkali-free accelerator for sprayed concrete.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the liquid alkali-free accelerator for sprayed concrete is characterized by comprising the following components in parts by weight: 20-50 parts of inorganic aluminum-containing substance, 5-10 parts of inorganic acid, 5-8 parts of alkyd substance, 2-5 parts of acidic stabilizer, 2-6 parts of solubilizing stabilizer, 1-3 parts of tackifier and 30-55 parts of water.
In a preferred embodiment, the accelerator further comprises 2-5 parts by weight of an unsaturated organic amine early strength agent.
In the present invention, the inorganic aluminum-containing substance is selected from aluminum sulfate, aluminum nitrate, aluminum phosphate, aluminum fluoride, aluminum triphosphate and combinations thereof, preferably the inorganic aluminum-containing substance is a combination of two substances, such as aluminum sulfate + aluminum nitrate, aluminum sulfate + aluminum phosphate, aluminum sulfate + aluminum fluoride, aluminum sulfate + aluminum triphosphate and the like, and the weight ratio of one inorganic aluminum-containing substance to another inorganic aluminum-containing substance is 1: 1-10: 1, more preferably 2: 1-5: 1.
In the present invention, the inorganic acid is selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, silicic acid, fluoroboric acid, meta-aluminate, and combinations thereof. Preferably, the inorganic acid is a combination of two acids, such as sulfuric acid + meta-aluminate, sulfuric acid + silicic acid, sulfuric acid + fluoroboric acid, sulfuric acid + phosphoric acid, and the like, and the weight ratio of one inorganic acid to the other inorganic acid is 1:1 to 10:1, more preferably 2:1 to 8: 1.
In the present invention, the alkyd-type material is an alkyd or thioacid compound having the following structural formula:
wherein R is H, straight chain or branched chain C1-C5An alkyl group.
For example, the alkyd based material is 2-hydroxybutyric acid, 2-mercaptopropionic acid, glycolic acid, thioglycolic acid, and the like.
In the present invention, the acidic stabilizer is selected from the group consisting of hydroxyethylidene diphosphonic acid, sorbic acid, fumaric acid, itaconic acid, sulfamic acid and combinations thereof, and the structural formulas thereof are respectively as follows:
for example, the acidic stabilizer is hydroxyethylidene diphosphonic acid; a combination of fumaric acid and sulfamic acid; a combination of sorbic and itaconic acid; a combination of hydroxyethylidene diphosphate and itaconic acid; and so on.
In the present invention, the solubilizing stabilizer is selected from the group consisting of stearyl alcohol, sucrose fatty acid esters, hydrogenated castor oil, stearic acid, fatty acid diethoxy hydroxyethyl methyl ammonium methosulfate, octylphenol polyoxyethylene ether, cocamidopropyl betaine, ethylene glycol distearate, sorbitan monooleate, glyceryl monostearate, silica, and combinations thereof. For example, the solubilizing stabilizer is a combination of stearyl alcohol and ethylene glycol distearate, a combination of sucrose fatty acid ester and glyceryl monostearate, cocamidopropyl betaine, fatty acid ethyl ester hydroxyethyl methyl ammonium methyl sulfate, and the like.
In the present invention, the tackifier is selected from the group consisting of anionic polyacrylamide, carrageenan, sesbania gum, sodium polyacrylate, welan gum, guar gum, sodium alginate, polyacrylamide emulsion, polyamide wax, microcrystalline cellulose, and combinations thereof. For example, the viscosity increasing agent is microcrystalline cellulose, sodium polyacrylate, sodium alginate, carrageenan, and the like.
The unsaturated organic amine early strength agent adopted in the tackifier of the invention is a beta-diketone imine compound with the following structural formula:
wherein Ar is
R2、R3、R4、R5、R6Are identical or different and are each independently-H, straight-chain or branched C1-C5Alkoxy, -OH or-NH2. Preferably R2is-NH2And/or R6is-NH2。
Correspondingly, the invention also provides a preparation method of the liquid alkali-free accelerator, which is characterized by comprising the following steps:
1) preparing a mother solution: adding the water, the inorganic aluminum-containing substance and the inorganic acid in parts by weight into a reaction kettle, heating to 90-110 ℃, and stirring for 0.5-2 hours to fully dissolve the inorganic aluminum-containing substance to obtain mother liquor;
2) preparing a semi-finished product: cooling the mother liquor obtained in the step 1) to 50-60 ℃, then adding the alkyd substances, the acidic stabilizer, the solubilizing stabilizer, the tackifier and the unsaturated organic amine early strength agent in parts by weight, and stirring for 0.5-5 hours to fully and uniformly mix the components to obtain a semi-finished product of the alkali-free accelerator;
3) and (3) preparing a finished product: stirring the semi-finished product obtained in the step 2) for 15-60 min by using a high-speed stirrer at the rotating speed of 1500-4000 r/min to obtain the finished product of the alkali-free accelerator.
In the preparation method of the invention, the rotating speed of the high-speed stirrer is preferably 2000-2800 r/min.
Correspondingly, the invention also provides an early strength agent which is a beta-diketoimine compound with the following structural formula:
wherein Ar is
R2、R3、R4、R5、R6Are identical or different and are each independently H, straight-chain or branched C1-C5Alkoxy, -OH or-NH2. Preferably R2is-NH2And/or R6is-NH2。
The liquid alkali-free accelerator for sprayed concrete prepared by the invention has good spraying effect, and experiments show that various indexes of the cement adopting the liquid alkali-free accelerator can meet the requirements of GB/T35159-2017, such as initial setting time, final setting time, mortar 1d compressive strength, mortar 28d compressive strength ratio, 90d strength retention value and the like.
The liquid alkali-free accelerator is a weakly acidic to neutral liquid, has a shelf life of more than 6 months, and does not have a layering phenomenon. In addition, the sprayed concrete doped with the liquid alkali-free accelerator has almost no dust in the spraying process, the environmental pollution is small, and the rebound rate is below 8 percent, so that the economic loss caused in the spraying process is greatly reduced.
Drawings
FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of (E) -N1- ((Z) -4- (mesitylamino) pent-3-en-2-imido) benzene-1, 2-diamine, an early strength agent of example 1.
Detailed Description
The structural formula of the alkyd or thioacid compounds in the present inventionIn the formula, "-O (S) H" represents-OH or-SH.
To make the objects, technical solutions and advantages of the present invention clearer and more complete description will be given below with reference to the following embodiments, which are obviously a part of the embodiments of the present invention, rather than the whole embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Firstly, preparing an early strength agent:
example 1 Synthesis of (E) -N1- ((Z) -4- (mesitylamino) pent-3-en-2-imido) benzene-1, 2-diamine
The preparation was carried out according to the following synthetic route, with reference to the method described in Eur.J.Inorg.chem (1998, 1485-1494).
The method comprises the following specific steps:
a250 ml three-necked flask was charged with anhydrous ethanol (150ml), 2,4, 6-trimethyltoluidine (15ml,48.95mmol), and then concentrated hydrochloric acid (4ml) to produce a large amount of white mist. Stirring was started and after 5 minutes acetophenon (5ml) was added using a constant pressure dropping funnel. Stirring at room temperature for 30 min, then raising the temperature to 100 deg.C, refluxing for 72 h, monitoring by TLC, after the reaction is complete, the system is a brown liquid, using CH2CL2Extracted three times (10ml) with saturated NaHCO3Neutralizing with water solution (10ml), vacuum-drying solvent, recrystallizing with methanol (5ml) to obtain white solid, and identifying by NMR to obtain target compound (E) -N1- ((Z) -4- (mesitylamino) pent-3-en-2-imino) benzene-1, 2-diamine.
1H NMR(500MHz,CDCl3)δ1.68(s,6H),2.11(s,12H),2.25(s,6H),4.85(s,1H),6.85(s,4H),12.15(s,1H)。
Example 2 Synthesis of (E) -N1- ((Z) -4- ((2-amino-5-methoxyphenyl) amino) pent-3-en-2-imi-do) -5-methoxybenzene-1, 2-diamine
(E) -N1- ((Z) -4- ((2-amino-5-methoxyphenyl) amino) pent-3-en-2-imido) -5-methoxybenzene-1, 2-diamine was synthesized in a similar manner to example 1.
Example 3 Synthesis of (E) -N1- ((Z) -4- ((3-aminophenyl) amino) pent-3-en-2-imido) benzene-1, 3-diamine
(E) -N1- ((Z) -4- ((3-aminophenyl) amino) pent-3-en-2-imido) benzene-1, 3-diamine was synthesized in a similar manner to example 1.
Example 4 Synthesis of 3-amino-4- ((E) - ((Z) -4- ((2-amino-4-hydroxy-6-methoxyphenyl) amino) pent-3-en-2-ylidene) amino) -5-methoxyphenol
3-amino-4- ((E) - ((Z) -4- ((2-amino-4-hydroxy-6-methoxyphenyl) amino) pent-3-en-2-ylidene) amino) -5-methoxyphenol was synthesized in a similar manner to example 1.
Preparation of liquid alkali-free accelerator
Example 5
Respectively weighing 37 parts of water, 5 parts of sulfuric acid, 2 parts of metaaluminic acid, 30 parts of aluminum sulfate and 10 parts of aluminum nitrate by weight, sequentially adding the weighed materials into a reaction kettle, heating to 95 ℃, and stirring for 1 hour to fully dissolve the aluminum sulfate and the aluminum nitrate to obtain mother liquor.
Cooling the obtained mother liquor to 55 ℃, then respectively weighing 5 parts of 2-hydroxybutyric acid, 3 parts of hydroxyethylidene diphosphonic acid, 2 parts of octadecanol, 1 part of ethylene glycol distearate, 2 parts of microcrystalline cellulose and 3 parts of (E) -N1- ((Z) -4- (mesitylamino) pent-3-ene-2-imino) benzene-1, 2-diamine in parts by weight, sequentially adding the mixture into a reaction kettle, and stirring for 1.5 hours to fully and uniformly mix the components to obtain the semi-finished product of the alkali-free accelerator.
Starting a high-speed stirrer, adjusting the rotating speed to 2200r/min, and stirring for 0.5 hour to obtain the liquid alkali-free accelerator for the sprayed concrete.
Example 6
Respectively weighing 38 parts of water, 4 parts of sulfuric acid, 1 part of silicic acid, 31 parts of aluminum sulfate and 9 parts of aluminum phosphate by weight, sequentially adding the materials into a reaction kettle, heating to 95 ℃, and stirring for 1 hour to fully dissolve the aluminum sulfate and the aluminum phosphate to obtain mother liquor.
Cooling the obtained mother liquor to 55 ℃, then respectively weighing 6 parts of 2-mercaptopropionic acid, 2 parts of fumaric acid, 1 part of sulfamic acid, 1 part of sucrose fatty acid ester, 1 part of glycerin monostearate, 1 part of sodium polyacrylate and 2 parts of (E) -N1- ((Z) -4- ((2-amino-5-methoxyphenyl) amino) pent-3-en-2-imino) -5-methoxybenzene-1, 2-diamine in parts by weight, sequentially adding the components into a reaction kettle, and stirring for 1.5 hours to fully and uniformly mix the components to obtain the semi-finished product of the alkali-free accelerator.
Starting a high-speed stirrer, adjusting the rotating speed to 2200r/min, and stirring for 0.5 hour to obtain the liquid alkali-free accelerator for the sprayed concrete.
Example 7
Respectively weighing 37 parts of water, 4 parts of sulfuric acid, 2 parts of fluoboric acid, 33 parts of aluminum sulfate and 8 parts of aluminum fluoride by weight, sequentially adding the water, the sulfuric acid, the fluoboric acid, the aluminum sulfate and the aluminum fluoride into a reaction kettle, heating to 95 ℃, and stirring for 1 hour to fully dissolve the aluminum sulfate and the aluminum fluoride to obtain mother liquor.
Cooling the obtained mother liquor to 55 ℃, then respectively weighing 7 parts of glycolic acid, 1 part of sorbic acid, 1 part of itaconic acid, 3 parts of cocamidopropyl betaine, 1 part of sodium alginate, and 3 parts of (E) -N1- ((Z) -4- ((3-aminophenyl) amino) pent-3-ene-2-imino) benzene-1, 3-diamine in parts by weight, sequentially adding the components into a reaction kettle, and stirring for 1.5 hours to fully and uniformly mix the components to obtain a semi-finished product of the alkali-free accelerator.
Starting a high-speed stirrer, adjusting the rotating speed to 2200r/min, and stirring for 0.5 hour to obtain the liquid alkali-free accelerator for the sprayed concrete.
Example 8
Respectively weighing 38 parts of water, 6 parts of sulfuric acid, 1 part of phosphoric acid, 32 parts of aluminum sulfate and 9 parts of aluminum triethyl phosphate by weight, sequentially adding the water, the sulfuric acid, the phosphoric acid, the aluminum sulfate and the aluminum triethyl phosphate into a reaction kettle, heating to 95 ℃, and stirring for 1 hour to fully dissolve the aluminum sulfate and the aluminum triethyl phosphate to obtain mother liquor.
Cooling the obtained mother liquor to 55 ℃, then respectively weighing 6 parts of mercaptoglycolic acid, 2 parts of hydroxyethylidene diphosphonic acid, 1 part of itaconic acid, 2 parts of fatty acid ethyl ester hydroxyethyl methyl ammonium methyl sulfate, 1 part of carrageenan and 2 parts of 3-amino-4- ((E) - ((Z) -4- ((2-amino-4-hydroxy-6-methoxyphenyl) amino) pent-3-en-2-ylidene) amino) -5-methoxyphenol by weight, sequentially adding the components into a reaction kettle, and stirring for 1.5 hours to fully and uniformly mix the components to obtain a semi-finished product of the alkali-free accelerator.
Starting a high-speed stirrer, adjusting the rotating speed to 2200r/min, and stirring for 0.5 hour to obtain the liquid alkali-free accelerator for the sprayed concrete.
In order to better explain the performance of the product, the accelerating agents of Yunnan and Jiangsu manufacturers in the market are selected as comparison samples, and red lion, conch and southwest P.O 42.5.5 cement are used as accelerating agent detection experiments to detect various performances of the accelerating agent. The folding and fixing content of the accelerator used in the experiment is 6%, and the experiment results are shown in table 1.
TABLE 1 comparison of the Properties of liquid alkali-free accelerators
In order to better regulate the performance indexes of the liquid alkali-free accelerator, a new GB/T35159-2017 accelerator for sprayed concrete is provided in the country in 2017. As can be seen from the data in Table 1, after the liquid alkali-free setting accelerator of the invention in the examples 5-8 is doped, the initial setting time of cement of three manufacturers, namely red lion, conch and southwest, is less than 3min, the final setting time is less than 5min, the 1d compressive strength is more than 9MPa, the 28d compressive strength ratio is 100-120%, and the 90d compressive strength retention value is 100-120%. It can be seen that after the liquid alkali-free accelerator disclosed by the embodiment 5-8 of the invention is doped, all performance indexes of cement of three manufacturers, namely red lion, conch and southwest, are far higher than standard requirements, and are remarkably superior to two products of Yunnan manufacturers and Jiangsu manufacturers on the market.
Third, comparative example
In addition, according to the method of the alkali-free accelerator in the embodiment 5, the early strength agents prepared in the early strength agent embodiments 1-4 are respectively adopted, other components and the using amount of the early strength agents are kept unchanged, and the obtained alkali-free accelerator is detected according to the accelerator detection experiment to determine the influence of the early strength agents on the coagulation performance of the alkali-free accelerator containing the early strength agents.
The obtained alkali-free accelerators were designated as sample 1 (with addition of (E) -N1- ((Z) -4- (mesitylamino) pent-3-en-2-imido) benzene-1, 2-diamine), sample 2 (with addition of (E) -N1- ((Z) -4- ((2-amino-5-methoxyphenyl) amino) pent-3-en-2-imido) -5-methoxybenzene-1, 2-diamine), sample 3 (with addition of (E) -N1- ((Z) -4- ((3-aminophenyl) amino) pent-3-en-2-imido) benzene-1, 3-diamine), and sample 4 (with addition of 3-amino-4- ((E) - ((Z) -4- ((2-amino-4-hydroxy-6-methoxyphenyl) amino) pent-3-en-2-ylidene) amino) -5-methoxyphenol). The results of the experiment are shown in table 2.
TABLE 2 Experimental results of the effect of early strength agent on setting performance of alkali-free setting accelerator
As can be seen from the data in Table 2, the setting time of the cement with the accelerator added to sample 1 was prolonged, the setting time of the cement with the accelerator added to sample 2 and the setting time of the cement with the accelerator added to sample 4 were both shorter, the setting time was shortened by about 1min, and the compressive strength at 1d and the compressive strength at 28d were slightly improved as compared with the setting time of sample 3. From this, it was confirmed that, in the beta-diketoimine-based compound early strength agent, if the substituent on Ar is free of-NH2The setting performance of the alkali-free quick-setting admixture comprising the early strength agent may be deteriorated if the substituent R on Ar2And/or R6is-NH2The setting performance of the alkali-free quick-setting admixture comprising the early strength agent can be made better.
The above description is only a preferred embodiment and example of the present invention, and therefore should not be construed as limiting the scope of the present invention, i.e., any equivalent changes and modifications made in the specification should be covered by the present invention.
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