CN114455881A - Non-aqueous liquid alkali-free accelerator and preparation method thereof - Google Patents
Non-aqueous liquid alkali-free accelerator and preparation method thereof Download PDFInfo
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- CN114455881A CN114455881A CN202210381272.5A CN202210381272A CN114455881A CN 114455881 A CN114455881 A CN 114455881A CN 202210381272 A CN202210381272 A CN 202210381272A CN 114455881 A CN114455881 A CN 114455881A
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- aluminum
- liquid alkali
- free accelerator
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/0028—Aspects relating to the mixing step of the mortar preparation
- C04B40/0039—Premixtures of ingredients
- C04B40/0046—Premixtures of ingredients characterised by their processing, e.g. sequence of mixing the ingredients when preparing the premixtures
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
- C04B2103/10—Accelerators; Activators
- C04B2103/12—Set accelerators
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention provides a non-aqueous phase liquid alkali-free accelerator and a preparation method thereof, wherein the preparation method comprises the following steps: step 1 is to prepare a modified organic aluminum salt: stirring a solvent, introducing nitrogen into the solvent, then adding alkyl aluminum, uniformly mixing, adding alkyl aluminum hypophosphite, and stopping introducing nitrogen after reaction to obtain modified organic aluminum salt; step 2 is to prepare a non-aqueous phase liquid alkali-free accelerator: stirring the modified organic aluminum salt, adding a thickening agent into the modified organic aluminum salt, uniformly mixing, adding a reinforcing agent into the mixture, and keeping the temperature after the reaction is finished to obtain the non-aqueous liquid alkali-free accelerator. The main accelerating component of the non-aqueous phase liquid alkali-free accelerator is a reaction product of alkyl aluminum and alkyl aluminum hypophosphite, and the reaction product reacts with free water in concrete to generate aluminum hydroxide and partial free aluminum ions, and the components are used as direct accelerating components to accelerate the hydration process of cement so as to realize concrete accelerating.
Description
Technical Field
The invention belongs to the field of concrete, and particularly relates to a non-aqueous liquid alkali-free accelerator and a preparation method thereof.
Background
The accelerating agent, namely an additive which is mixed into the concrete and can quickly set and harden the concrete, can be divided into powder and liquid according to the form, and can be divided into alkali and alkali-free according to the characteristics. After the cement is mixed, the rapid hydration and the setting of the cement can be promoted, and enough strength can be formed in a short time so as to achieve the purpose of rapid setting of concrete in rush repairs or roadways, and the cement is an indispensable additive in a sprayed concrete construction method.
With the current increasing concern on environmental friendliness and concrete durability, the liquid alkali-free accelerator gradually becomes a mainstream product by virtue of the advantages of alkali-free property, chlorine-free property, no pungent smell, good caking property, low rebound quantity, high later strength preservation rate, high impermeability level and the like.
The existing liquid alkali-free accelerator technology mainly uses water as a solvent, soluble aluminum sulfate as a main accelerating component, and other components (such as organic alcohol amine, inorganic fluoride and the like) for increasing the solubility, early strength components (alkali metal inorganic salt), constructability improving components and the like as auxiliary materials.
The main component of the alkali-free accelerator system, namely aluminum salt, is mainly Al in water3+The ionic form exists, but is very easy to react with OH in water along with the prolonging of the storage period-React to form precipitateThe precipitation, and thus the loss of the accelerating effect, is also the source of the shelf life problem of the liquid accelerator.
Meanwhile, as the storage ambient temperature decreases, Al3+The aqueous solubility of the ions is also reduced, and precipitation problems also occur. In addition, the water content of the accelerator (about 30-50%) can crystallize at negative temperature, causing the product to freeze and reduce performance.
As the main synthetic raw materials of the liquid alkali-free setting accelerator of various manufacturers in the current industry are basically consistent, the selection of a brand-new set accelerating component or solvent becomes the key point for solving the technical problem.
Disclosure of Invention
In view of the above, the present invention provides a non-aqueous liquid alkali-free accelerator and a preparation method thereof, which aims to overcome the defects in the prior art.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
a non-aqueous liquid alkali-free accelerator is prepared from the following raw materials in parts by weight:
30-45 parts of alkyl aluminum,
10-15 parts of aluminum alkyl hypophosphite,
4-6 parts of a reinforcing agent,
0.1 to 0.4 portion of thickening agent,
33.6-55.9 parts of solvent.
Further, the alkyl aluminum is triethyl aluminum and/or tributyl aluminum.
Further, the alkyl aluminum hypophosphite is dimethyl aluminum hypophosphite and/or diethyl aluminum hypophosphite.
Further, the enhancer is at least one of calcium formate, calcium acetate or calcium propionate.
Further, the thickening agent is at least one of hydroxymethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose.
Further, the solvent is at least one of pentane, hexane or heptane.
The preparation method of the non-aqueous liquid alkali-free accelerator comprises the following steps:
step 1 is to prepare a modified organic aluminum salt: stirring a solvent, introducing nitrogen into the solvent, then adding alkyl aluminum, uniformly mixing, adding alkyl aluminum hypophosphite, and stopping introducing nitrogen after reaction to obtain modified organic aluminum salt;
step 2 is to prepare a non-aqueous phase liquid alkali-free accelerator: stirring the modified organic aluminum salt, adding a thickening agent into the modified organic aluminum salt, uniformly mixing, adding a reinforcing agent into the mixture, and keeping the temperature after the reaction is finished to obtain the non-aqueous liquid alkali-free accelerator.
Further, the temperature of the stirring step in the step 1 is below 10 ℃; the time of the reaction step in the step 1 is 1-2 hours.
Further, the time of the reaction step in the step 2 is 105-135 minutes, and the temperature is 15-20 ℃.
The aluminum alkyl hypophosphite is used as a synergistic component, can obviously improve the comprehensive performance of the product and is mainly shown in the following steps:
firstly, the chemical structure of the catalyst is similar to that of alkyl aluminum, and mutual solubility can be well generated (the principle of similar mutual solubility), so that the reaction process is more uniform. Meanwhile, the phosphate group has a good chelating coordination effect and can fix free aluminum ions in a system, so that the product system is more stable, and the shelf life is remarkably prolonged;
secondly, the alkyl aluminum has flammable characteristics and active chemical properties in the raw material stage; the alkyl aluminum hypophosphite is a flame retardant with excellent performance, and after the alkyl aluminum hypophosphite is chemically bonded with alkyl aluminum, free radicals can be generated when the aluminum hypophosphite is heated to inhibit subsequent chain reaction, so that the performance defect of the alkyl aluminum is effectively overcome, and the controllability of the first-stage reaction of the product is improved;
in addition, after the reactants of the alkyl aluminum and the alkyl aluminum hypophosphite contact the concrete, a large amount of long-chain alkane components can be decomposed, the cohesiveness of the sprayed concrete can be obviously improved, the spraying resilience rate is reduced, the concrete waste can be reduced, and the site construction environment can be obviously improved.
Compared with the prior art, the invention has the following advantages:
the main accelerating component of the non-aqueous phase liquid alkali-free accelerator is a reaction product of alkyl aluminum and alkyl aluminum hypophosphite, and the reaction product reacts with free water in concrete to generate aluminum hydroxide and partial free aluminum ions, and the components are used as direct accelerating components to accelerate the hydration process of cement so as to realize the quick setting of the concrete.
The non-aqueous phase liquid alkali-free accelerator provided by the invention adopts long-chain alkane as a system solvent, so that the problem of effective component precipitation caused by solubility is effectively solved.
The storage stability period of the non-aqueous liquid alkali-free accelerator provided by the invention is obviously longer than that of a market (aluminum sulfate and water-based) product, and the problem of deterioration caused by product storage time or environment can be greatly improved. Meanwhile, the requirement on the storage environment is greatly reduced, and particularly, heating and heat preservation are not needed in cold regions, so that resource waste is effectively reduced.
Detailed Description
Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods are conventional methods unless otherwise specified.
The present invention will be described in detail with reference to examples.
Example 1
A preparation method of a non-aqueous phase liquid alkali-free accelerator comprises the following steps:
(1) adding 55.6g of pentane into a reaction vessel, starting a stirring device, controlling the temperature to be 5-10 ℃, simultaneously starting to introduce nitrogen from the bottom of the reaction vessel, adding 30g of triethyl aluminum into the reaction vessel until the triethyl aluminum and a solvent are uniformly mixed, then adding 10g of dimethyl aluminum hypophosphite, reacting for 2 hours, and stopping introducing the nitrogen to prepare modified organic aluminum salt;
(2) adding modified organic aluminum salt into a reaction container, starting a stirring device, sequentially adding 0.4g of hydroxymethyl cellulose and 4g of calcium formate, ensuring that each material can be added after being uniformly stirred, controlling the reaction time to be 2 hours after the feeding is finished, ensuring the temperature of a reactant to be 15-20 ℃ through a temperature control measure in the whole process, and obtaining the modified accelerator after the reaction is finished.
Example 2
A preparation method of a non-aqueous phase liquid alkali-free accelerator comprises the following steps:
(1) adding 34.8g of hexane into a reaction vessel, starting a stirring device, controlling the temperature to be 5-10 ℃, simultaneously starting to introduce nitrogen from the bottom of the reaction vessel, adding 45g of tributyl aluminum into the reaction vessel until the tributyl aluminum is uniformly mixed with a solvent, then adding 15g of diethyl aluminum hypophosphite, reacting for 2 hours, and stopping introducing the nitrogen to prepare modified organic aluminum salt;
(2) adding modified organic aluminum salt into a reaction container, starting a stirring device, sequentially adding 0.2g of hydroxyethyl cellulose and 5g of calcium acetate, ensuring that each material can be added after being uniformly stirred, controlling the reaction time to be 2 hours after the feeding is finished, ensuring the temperature of reactants to be 15-20 ℃ through temperature control measures in the whole process, and obtaining the modified accelerator after the reaction is finished.
Example 3
The only difference from example 1 is that: 35g of triethyl aluminum and 12g of dimethyl aluminum hypophosphite.
Example 4
The only difference from example 1 is that: 40g of triethyl aluminum and 13g of dimethyl aluminum hypophosphite.
Comparative example 1
The only difference from example 1 is that: 20g of triethyl aluminum and 7g of dimethyl aluminum hypophosphite.
Comparative example 2
The only differences from example 1 are: (1) adding 55.6g of pentane into the reaction vessel, starting a stirring device, controlling the temperature to be 5-10 ℃, simultaneously starting to introduce nitrogen from the bottom of the reaction vessel, then adding 10g of aluminum dimethyl hypophosphite, reacting for 2 hours, and stopping introducing the nitrogen to prepare the modified organic aluminum salt.
Comparative example 3
The only difference from example 1 is that: (1) adding 55.6g of pentane into a reaction vessel, starting a stirring device, controlling the temperature to be 5-10 ℃, simultaneously starting to introduce nitrogen from the bottom of the reaction vessel, adding 30g of triethyl aluminum into the reaction vessel until the triethyl aluminum and the solvent are uniformly mixed, and stopping introducing the nitrogen after reacting for 2 hours to prepare the modified organic aluminum salt.
Comparative example 4
The only difference from example 1 is that: (1) adding 55.6g of pentane into a reaction vessel, starting a stirring device, controlling the temperature to be 5-10 ℃, simultaneously starting to introduce nitrogen from the bottom of the reaction vessel, adding 30g of aluminum isopropoxide into the reaction vessel until the aluminum isopropoxide and a solvent are uniformly mixed, then adding 10g of aluminum dimethyl hypophosphite, reacting for 2 hours, and stopping introducing the nitrogen to prepare the modified organic aluminum salt.
Comparative example 5
The only difference from example 1 is that: (1) adding 55.6g of pentane into a reaction vessel, starting a stirring device, controlling the temperature to be 5-10 ℃, simultaneously starting to introduce nitrogen from the bottom of the reaction vessel, adding 30g of triethyl aluminum into the reaction vessel until the triethyl aluminum and a solvent are uniformly mixed, then adding 10g of aluminium iso-butoxide, and stopping introducing nitrogen after reacting for 2 hours to prepare the modified organic aluminum salt.
Comparative example 6
SBT-N (II) liquid alkali-free setting accelerators produced by Jiangsu Subo new materials GmbH.
The performance of the accelerating agents obtained in examples 1-4 and comparative examples 1-6 is respectively compared according to the national standard GB/T35159-2017 accelerating agent for sprayed concrete of the product, and the results are as follows:
TABLE 1 Performance results
All non-water-based samples are obviously better than the conventional water-based samples in the market in terms of 90d stability of the product, wherein the alkali-free accelerating agents prepared in examples 1-4 and comparative example 1 are better in stability, and basically have no precipitation and delamination problems after 90 d.
The alkali-free accelerators obtained in examples 1 to 4 are all significantly superior to other samples in terms of setting time performance of the product, and are superior as the amount of the aluminum alkyl is increased. Meanwhile, the setting time performance of the accelerator prepared in the comparative example 1 is close to that of the conventional water-based sample in the market, and the setting time performance is in the qualified range.
The strength of the mortar in the 7d age period is only qualified by the alkali-free accelerating agent prepared in the examples 1-4 and the comparative example 1 and the conventional water-based samples in the market. The 28d compressive strength ratio and the 90d compressive strength retention index are not greatly influenced by the alkali-free setting accelerator (sensitive to alkali content only), and all samples are qualified.
Compared with the embodiment 1, the mixing amount of the main functional component in the comparative example 1 is changed, and the prepared accelerator belongs to qualified products, but the performance is obviously reduced; in the comparative example 2, no aluminum alkyl is added, so that the indexes of the prepared accelerator, such as the setting time, the 1d strength and the like, are obviously reduced, and the 90d storage stability is also reduced; in comparative example 3, no aluminum alkyl hypophosphite is added, the 90d stability of the prepared accelerator is obviously poor, and the indexes such as the sample coagulation time and the 1d strength are reduced to a certain extent due to the lack of part of active aluminum ions provided by the aluminum alkyl hypophosphite; compared with the comparative examples 4 and 5, aluminum isopropoxide is adopted to replace aluminum alkyl hypophosphite, the synergistic effect among the components is lost, and the overall performance is obviously reduced; comparative example 6A conventional water-based alkali-free setting accelerator manufactured by a commercially known manufacturer was used, and although the performance indexes of the accelerator were satisfactory, the 90d stability was significantly inferior to those of the alkali-free setting accelerators of examples 1 to 4, and since a large amount of components for increasing the solubility of aluminum ions in water, generally polyhydroxy or inorganic acids, were added, the problems of retardation or strength reduction were common, and therefore, the 1d strength was affected to a certain extent and was significantly lower than the 1d strength of the sample of the present invention.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (9)
1. A non-aqueous phase liquid alkali-free accelerator is characterized in that: the accelerator is prepared from the following raw materials in parts by weight:
30-45 parts of alkyl aluminum,
10-15 parts of aluminum alkyl hypophosphite,
4-6 parts of a reinforcing agent,
0.1 to 0.4 portion of thickening agent,
33.6-55.9 parts of solvent.
2. The non-aqueous liquid alkali-free accelerator according to claim 1, characterized in that: the alkyl aluminum is triethyl aluminum and/or tributyl aluminum.
3. The non-aqueous liquid alkali-free accelerator according to claim 1, characterized in that: the alkyl aluminum hypophosphite is dimethyl aluminum hypophosphite and/or diethyl aluminum hypophosphite.
4. The non-aqueous liquid alkali-free accelerator according to claim 1, characterized in that: the reinforcing agent is at least one of calcium formate, calcium acetate or calcium propionate.
5. The non-aqueous liquid alkali-free accelerator according to claim 1, characterized in that: the thickener is at least one of hydroxymethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose.
6. The non-aqueous liquid alkali-free accelerator according to claim 1, characterized in that: the solvent is at least one of pentane, hexane or heptane.
7. The method for producing a non-aqueous liquid alkali-free accelerator according to any one of claims 1 to 6, characterized in that: the method comprises the following steps:
step 1 is to prepare a modified organic aluminum salt: stirring a solvent, introducing nitrogen into the solvent, then adding alkyl aluminum, uniformly mixing, adding alkyl aluminum hypophosphite, and stopping introducing nitrogen after reaction to obtain modified organic aluminum salt;
step 2 is to prepare a non-aqueous phase liquid alkali-free accelerator: stirring the modified organic aluminum salt, adding a thickening agent into the modified organic aluminum salt, uniformly mixing, adding a reinforcing agent into the mixture, and keeping the temperature after the reaction is finished to obtain the non-aqueous liquid alkali-free accelerator.
8. The method for producing a non-aqueous liquid alkali-free accelerator according to claim 7, characterized in that: the temperature of the stirring step in the step 1 is below 10 ℃; the time of the reaction step in the step 1 is 1-2 hours.
9. The method for producing a non-aqueous liquid alkali-free accelerator according to claim 7, characterized in that: the reaction time in the step 2 is 105-135 minutes, and the temperature is 15-20 ℃.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006206367A (en) * | 2005-01-27 | 2006-08-10 | Sanyo Chem Ind Ltd | Additive for cement composition |
| CN102923988A (en) * | 2012-11-29 | 2013-02-13 | 北京冶建特种材料有限公司 | Liquid alkali-free chloride-free accelerating agent as well as methods for preparing and using same |
| CN103241975A (en) * | 2012-02-05 | 2013-08-14 | 张云侠 | Preparation method for sodium metasilicate nonahydrate liquid concrete accelerator |
| CN107963827A (en) * | 2017-09-29 | 2018-04-27 | 湖北工业大学 | Organic-inorganic composite alkali-free quick-coagulant and preparation method thereof |
| CN110615638A (en) * | 2019-10-15 | 2019-12-27 | 天津冶建特种材料有限公司 | Low-temperature-resistant liquid alkali-free setting accelerator and preparation method thereof |
-
2022
- 2022-04-13 CN CN202210381272.5A patent/CN114455881B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006206367A (en) * | 2005-01-27 | 2006-08-10 | Sanyo Chem Ind Ltd | Additive for cement composition |
| CN103241975A (en) * | 2012-02-05 | 2013-08-14 | 张云侠 | Preparation method for sodium metasilicate nonahydrate liquid concrete accelerator |
| CN102923988A (en) * | 2012-11-29 | 2013-02-13 | 北京冶建特种材料有限公司 | Liquid alkali-free chloride-free accelerating agent as well as methods for preparing and using same |
| CN107963827A (en) * | 2017-09-29 | 2018-04-27 | 湖北工业大学 | Organic-inorganic composite alkali-free quick-coagulant and preparation method thereof |
| CN110615638A (en) * | 2019-10-15 | 2019-12-27 | 天津冶建特种材料有限公司 | Low-temperature-resistant liquid alkali-free setting accelerator and preparation method thereof |
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