Composite early-strength anti-freezing water reducing agent and preparation method thereof

Abstract

The invention discloses a composite early-strength anti-freezing water reducing agent and a preparation method thereof. The composite early-strength anti-freezing water reducing agent comprises the following components: nitrate or nitrite, an alcohol anti-freezing component, alcohol amine, polycarboxylic acid high-performance water reducing agent mother liquor, a polyether air entraining agent and water. The method comprises the following steps: adding water into production equipment, sequentially adding nitrate or nitrite, methanol, ethylene glycol, hydramine and the polycarboxylic acid high-performance water reducing agent mother liquor, uniformly stirring, and discharging to obtain the product. The invention has the following advantages: the dosage form is a water agent, dust pollution is avoided, occupational health and safety of practitioners are protected, the labor cost of feeding is saved, the early-strength anti-freezing component and the water-reducing component are compounded together, and the water-reducing rate and concrete anti-freezing critical strength specified by national standards and industrial standards are reached under the condition that the dosage is determined, so that the dosage is reduced; the product can resist low temperature of-20 DEG C without crystallization, is not layered after being placed for a long time, and has no precipitate.

Description

Technical Field

[0001] The present invention relates to the technical field of building material preparation, and particularly to water reducing agents. Background Art

[0002] When entering winter construction, early strength antifreeze agents must be added to ready-mixed concrete, and the water-binder ratio of the mix proportion should be appropriately reduced. Traditional concrete early strength antifreeze agents are in powder form, mainly including chloride type, chloride rust inhibitor type, and sulfate type. The carriers are generally ultrafine stone powder or fly ash, which only have the function of early strength and a certain effect of reducing the freezing point of the liquid phase. When used in reinforced concrete structures, their chloride ions Cl ˉ and sulfate ions SO4 2ˉ have the risk of corroding steel bars. The lower the construction temperature, the greater the required dosage, and the greater this risk becomes.

[0003] The powder form generally has dust pollution during production, which increases the cost of environmental protection transformation for enterprises; at the same time, there is a risk of dust pollution during customer use. The dosage ranges provided by general enterprises corresponding to construction temperatures of -5°C, -10°C, and -15°C are 3.0%, 6.0%, and 9.0% respectively. Due to the high dosage, the labor cost is high and the efficiency is low.

[0004] When concrete construction enterprises are in production, they need to add separate early strength antifreeze agents and also need to add water reducing agents separately, resulting in high production raw material costs. Summary of the Invention

[0005] The purpose of the present invention is to provide a composite early strength antifreeze water reducing agent without dust pollution, low production cost, and low dosage, as well as its preparation method.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A composite early strength antifreeze water reducing agent, calculated by mass fraction, includes the following components:

[0008]

[0009] Further, the nitrate is calcium nitrate;

[0010] The nitrite is sodium nitrite or calcium nitrite.

[0011] Further, the alcohol-based antifreeze component includes methanol and ethylene glycol. Calculated by mass fraction, methanol is 3 - 5%, and ethanol is 1 - 2%.

[0012] Further, the polycarboxylate high-performance water reducing agent mother liquor is a No. 3 high water reducing type mother liquor with a solid content of 40%.

[0013] Further, the polyether type air-entraining agent is a Degussa microfoam type air-entraining agent imported from Germany.

[0014] Further, the alkanolamine is triethanolamine or diethanolamine.

[0015] The present invention also provides a preparation method of a composite early strength antifreeze water reducer, and the steps include:

[0016] According to the formula, water is added into the production equipment, and nitrate or nitrite, methanol, ethylene glycol, alkanolamine, and polycarboxylic high-performance water reducer mother liquor are added in sequence. After stirring evenly, the product can be obtained by discharging.

[0017] The advantages of the present invention are as follows:

[0018] 1. The dosage form adopts an aqueous solution. When downstream customers use it, they can use a weighing metering pump to extract, control the dosage accurately, eliminate dust pollution in the production and use links, protect the occupational health and safety of practitioners, and save the labor cost of feeding.

[0019] 2. It is a composite dosage form, which combines the early strength antifreeze component and the water reducing component. Under the condition of determining the use dosage, it can reach the water reducing rate and the concrete frost resistance critical strength specified in the national standards and industry standards.

[0020] 3. According to the requirements of the JC475-2004 "Concrete Antifreeze" standard, the corresponding dosages during construction at -5°C, -10°C, and -15°C are 3.0%, 4.0%, and 5.0% of the concrete binder respectively.

[0021] 4. The product itself can resist low temperature of -20°C without crystallization, does not stratify after long-term storage, and has no precipitate. Specific embodiments

[0022] The following will specifically describe the present invention in conjunction with specific embodiments. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but not to limit the present invention.

[0023] Example 1

[0024] This example provides a composite early strength antifreeze water reducer, which includes the following components by mass fraction:

[0025]

[0026]

[0027] The nitrate is calcium nitrate;

[0028] The nitrite is sodium nitrite or calcium nitrite.

[0029] The alcohol-based antifreeze component includes methanol and ethylene glycol. By mass fraction, methanol is 3-5%, and ethanol is 1-2%.

[0030] The polycarboxylate superplasticizer mother liquor is the No. 3 high-range water-reducing mother liquor with a solid content of 40%.

[0031] The alkanolamine is triethanolamine or diethanolamine.

[0032] The preparation method of the above composite early-strength and frost-resistant water reducer comprises the following steps:

[0033] According to the formula, add water into the production equipment, and sequentially add nitrate or nitrite, methanol, ethylene glycol, alkanolamine, and polycarboxylate superplasticizer mother liquor. After stirring evenly, the product can be obtained by discharging.

[0034] Example 2

[0035] This example provides a composite early-strength and frost-resistant water reducer, which comprises the following components by mass fraction:

[0036]

[0037] The rest is the same as in Example 1.

[0038] Example 3

[0039] This example provides a composite early-strength and frost-resistant water reducer, which comprises the following components by mass fraction:

[0040]

[0041]

[0042] The rest is the same as in Example 1.

[0043] Example 4

[0044] This example provides a composite early-strength and frost-resistant water reducer, which comprises the following components by mass fraction:

[0045]

[0046] Example 5

[0047] This example provides a composite early-strength and frost-resistant water reducer, which comprises the following components by mass fraction:

[0048]

[0049] The rest is the same as in Example 1.

[0050] Example 6

[0051] This example provides a composite early-strength and frost-resistant water reducer, which comprises the following components by mass fraction:

[0052]

[0053] The rest is the same as in Example 1.

[0054] Experiment 1

[0055] The test indexes for producing concrete with the composite high-performance early-strength and anti-freezing water reducer produced according to the above ratio are as follows:

[0056] I. Test basis: JC475-2004 "Concrete Anti-freezing Agent", GB8076-2008 "Concrete Admixture", GB / T50080-2002 "Standard for Test Methods of Performance of Ordinary Concrete Mixture"

[0057] II. Requirements for test materials:

[0058] Cement: Reference cement

[0059] Fine aggregate: Medium sand in Zone II meeting the requirements of GB / T14684, fineness modulus 2.6, water content less than 1.0%, silt content less than 1.0%

[0060] Crushed stone: Crushed stone meeting the particle size of 5-20mm (round-hole sieve) of GB / T14685, secondary grading, with 5-10mm accounting for 40% and 10-20mm accounting for 60%

[0061] Water: Municipal tap water

[0062] III. Sampling method: One batch is 50T. If less than 50T, it is counted as one batch. Samples are taken from the upper, middle and lower layers in the storage tank and then mixed evenly.

[0063] The test situation of Example 1 is shown in Table 1:

[0064] Table 1:

[0065]

[0066]

[0067] The test situation of Example 2 is shown in Table 2: Table 2:

[0068]

[0069]

[0070] The test situation of Example 3 is shown in Table 3: Table 3:

[0071]

[0072] The test situation of Example 4 is shown in Table 4: Table 4:

[0073]

[0074] The detection situation of Example 5 is shown in Table 5: Table 5:

[0075]

[0076]

[0077] The detection situation of Example 6 is shown in Table 6: Table 6:

[0078]

[0079]

[0080] Experiment 2

[0081] Comparison of the low-temperature form experiment of the target product:

[0082]

[0083] Typical excerpts of the experimental data in the above tables are presented in this article. It can be seen from the data that when optimized to the formulation data range, the raw material cost of the product is the best, and the hardening and frost resistance and tension resistance performance of the concrete fully meet and comprehensively exceed the relevant standard requirements such as JC475-2004 "Concrete Antifreeze Agent", GB8076-2008 "Concrete Admixture", and GB / T50080-2002 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures".

[0084] Advantages of the present invention:

[0085] 1. The dosage form is changed from the traditional powder to liquid, and there is no dust generation during the production process and use process, and there is no risk of pneumoconiosis, which is clean and environmentally friendly.

[0086] 2. The use of alkanolamine organic substances can effectively prevent the corrosion of steel bars by inorganic salts.

[0087] 3. The organic components and inorganic components are used in combination, with a lower dosage, better effect, and high cost performance.

[0088] 4. The early strength and antifreeze components are compounded with the water reducing component and the air entraining component, making the functions of the compound product more comprehensive, saving the raw material cost and manual feeding cost of the concrete, and having high cost performance.

[0089] 5. The dosage form is liquid, which can be transported by tank trucks, stored in cans, and pumped for use, saving packaging costs and avoiding the generation of solid waste.

[0090] 6. The scheme of combining an inorganic salt early strength agent with a higher solubility and an alcohol organic antifreeze component is adopted to rapidly improve the early hydration reaction of cement, so that the concrete structure can quickly reach the frost resistance critical strength value at low temperature.

[0091] 7. Organic alcohol early strength and antifreeze components can effectively lower the freezing point of the liquid phase water in the ready-mixed concrete, enabling the concrete mixture to still undergo hydration reactions at negative temperatures, increasing strength, and achieving antifreeze effects.

[0092] 8. The composite polycarboxylate superplasticizer component. As the construction temperature decreases, the dosage increases, and the water reduction rate increases significantly, reducing the water-binder ratio, which is beneficial to shortening the initial setting and final setting times of the concrete mixture, enabling the hydration heat of the mixture to be released concentratedly, and achieving antifreeze effects.

[0093] 9. The composite high-performance polyether air-entraining component. At the recommended dosage, the air content of the concrete mixture can reach 3.0% - 5.0%, and the surface of the component is smooth after form removal, without harmful large air bubbles. The introduced microbubble component can effectively improve the frost heaving resistance, flexural performance, and carbonation resistance of the concrete at negative temperatures.

[0094] The above has introduced in detail the technical solutions provided by the embodiments of the present invention. Specific examples are used herein to elaborate on the principles and implementation manners of the embodiments of the present invention. The descriptions of the above embodiments are only applicable to helping understand the principles of the embodiments of the present invention; at the same time, for those of ordinary skill in the art, based on the embodiments of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A composite early strength antifreeze water reducing agent, characterized in that: By mass fraction, it includes the following components:

2. A composite early strength antifreeze water reducing agent according to claim 1, characterized in that: The nitrate is calcium nitrate; The nitrite is sodium nitrite or calcium nitrite.

3. A composite early strength antifreeze water reducing agent according to claim 1 or 2, characterized in that: The alcohol antifreeze component comprises methanol and ethylene glycol, wherein the methanol is 3-5% and the ethanol is 1-2% by mass.

4. The composite early strength antifreeze water reducing agent according to claim 1, characterized in that: The polycarboxylic acid high performance water reducing agent mother liquor is a No. 3 high water reducing agent mother liquor with a solid content of 40%.

5. The composite early strength antifreeze water reducing agent according to claim 1, characterized in that: The polyether air-entraining agent is a Degussa micro-foam type polyether air-entraining agent imported from Germany.

6. The composite early-strength antifreeze water-reducing agent according to claim 1, characterized in that: The alcoholamine is triethanolamine or diethanolamine.

7. A method for preparing a composite early strength antifreeze water reducing agent according to any one of claims 1 to 5, characterized in that: The steps include: According to the formula, water is added into the production equipment, and then nitrate or nitrite, methanol, ethylene glycol, alcohol amine and polycarboxylic acid high performance water reducing agent mother liquor are added in sequence, and the material can be obtained after being evenly stirred.

Images