A low-carbon and easy-to-mix concrete admixture, preparation method and use thereof

Abstract

The present invention provides a low-carbon and easy-to-mix concrete admixture, a preparation method and use thereof, wherein the low-carbon and easy-to-mix concrete admixture comprises the following components in weight proportion: 30-60 parts of methoxy polyoxyethylene ether; 270-330 parts of modified alkylene polyoxyethylene ether; 3-7 parts of iodothioacetylcholine; 0.2-1.7 parts of ferrous sulfate solution; 1.0-3.0 parts of ammonium persulfate; 200-250 parts of water; 30-40 parts of maleic anhydride; 15-25 parts of hydroxyethyl acrylate; 20-30 parts of water; 0.1-0.35 parts of vitamin C; 0.20-0.4 parts of hanging white powder; 0.5-1.5 parts of mercaptoethanol; 60-90 parts of water. The concrete admixture is prepared by a raw material formula with no carbon emission and low carbon emission, and is produced at low energy consumption at room temperature. While ensuring the strength of concrete, the use of vibrating equipment in concrete construction is reduced, and it is ensured that long-distance transportation does not lose water reduction and collapse protection performance.

Description

Technical Field

[0001] The invention relates to concrete additive technology, in particular to a low-carbon and easy-to-mix concrete admixture, a preparation method and use thereof. Background Art

[0002] In the process of concrete construction, traditional concrete additives are mainly used for water reduction and collapse prevention. Traditional concrete additives are mainly naphthalene-based high-efficiency water reducers, lignin water reducers, aminosulfonate water reducers and polycarboxylic acid water reducers. Traditional products have single functions, only have water reduction or collapse prevention performance, high dosage, short fluidity retention time, poor performance, high content of toxic substances and other disadvantages. For example, CN109336447 discloses a stable collapse-preventing agent and a preparation and use method thereof, which discloses a stable collapse-preventing agent made of the following raw material components: an unsaturated polyether composition; an acrylic monomer; an inhibitor; a catalyst; an oxidant; a reducing agent; a molecular weight regulator; a pH regulator and water, wherein the unsaturated polyether composition comprises a first unsaturated polyether and a second unsaturated polyether, and the number average molecular weight of the first unsaturated polyether is less than the number average molecular weight of the second unsaturated polyether; the molecular weight regulator comprises mercaptopropionic acid and / or thioglycol; the inhibitor comprises hydroquinone; the catalyst comprises p-toluenesulfonic acid; the oxidant comprises hydrogen peroxide; the reducing agent comprises one or more of TP1351 and ferrous sulfate heptahydrate; and the pH regulator comprises an alkali metal hydroxide or an alkaline earth metal hydroxide.

[0003] Traditional concrete admixtures undergo high-temperature chemical reactions during the preparation process, and there is a certain amount of carbon dioxide emissions during the oxidation process, which is not conducive to environmental protection. In recent years, with the increasing awareness of environmental protection, the necessary natural sand and gravel in concrete has gradually been replaced by artificial sand and gravel. Compared with natural sand and gravel, artificial sand and gravel have not experienced long-term wind and sun exposure. The corners of artificial sand and gravel are relatively sharper, not as smooth as natural sand and gravel. Therefore, after artificial sand and gravel are added to concrete, the fluidity of concrete decreases, resulting in the need to increase vibration or reduce the construction surface during concrete construction. In addition, concrete mixed with artificial sand and gravel is often not suitable for long-distance transportation, or the fluidity of concrete is weakened after long-distance transportation, making it difficult to mix. Therefore, it is imperative to update the technology of concrete additives. Summary of the invention

[0004] The purpose of the present invention is to propose a low-carbon and easy-to-mix concrete admixture, which is formulated with raw materials with no carbon emissions and low carbon emissions, and is produced at room temperature with low energy consumption, in view of the fact that traditional concrete additives have certain carbon dioxide emissions during the preparation process and the mixing properties of concrete are reduced after using artificial sand and stone raw materials. It has the advantages of small dosage and high comprehensive performance. While ensuring the strength of concrete, it reduces the use of vibration equipment in concrete construction and ensures that the water-reducing and slump-preserving properties are not lost during long-distance transportation. It is a new type of low-carbon concrete admixture technology.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: using raw materials with no carbon emissions and low carbon emissions to increase the molecular fluidity between the raw materials in the concrete, produce a lubricating effect, and make the raw materials with edges and corners have more fluid working performance. It is a low-carbon and easy-to-mix concrete admixture, including the following components in weight proportion:

[0006] (1) Base material:

[0007]

[0008] (2) Liquid A:

[0009] Maleic anhydride 30-40 parts;

[0010] 15-25 parts of hydroxyethyl acrylate;

[0011] 20-30 parts water;

[0012] (3) Liquid B:

[0013]

[0014] Furthermore, the low-carbon concrete admixture preferably includes the following components in proportion by weight:

[0015] (1) Base material:

[0016]

[0017] (2) Liquid A:

[0018] Maleic anhydride 33-37 parts;

[0019] 18-22 parts of hydroxyethyl acrylate;

[0020] 22-28 parts water;

[0021] (3) Liquid B:

[0022]

[0023] Furthermore, the low-carbon concrete admixture more preferably includes the following components in proportion by weight:

[0024] (1) Base material:

[0025]

[0026] (2) Liquid A:

[0027] Maleic anhydride 35 parts;

[0028] 20 parts of hydroxyethyl acrylate;

[0029] 25 parts water;

[0030] (3) Liquid B:

[0031]

[0032] Furthermore, the concentration of the ferrous sulfate solution is 0.5-1.5%wt, preferably 0.7-1.3%wt, and more preferably 1%wt.

[0033] Furthermore, the concentration of ammonium persulfate is 20-30%wt, preferably 25-28%wt, and more preferably 27.5%wt.

[0034] Furthermore, the low-carbon and easy-to-use concrete admixture further includes (4) a water retaining agent, wherein the water retaining agent includes:

[0035] 1-2 parts xanthan gum powder;

[0036] 30-50 parts of water.

[0037] Furthermore, the preferred water-retaining agent includes:

[0038] 1.2-1.8 parts of xanthan gum powder;

[0039] 35-45 parts of water.

[0040] Furthermore, the more preferred water-retaining agent includes:

[0041] 1.5 parts of xanthan gum powder;

[0042] 40 parts of water.

[0043] Furthermore, the xanthan gum powder is edible grade xanthan gum powder.

[0044] Another object of the present invention is to disclose a method for preparing a low-carbon and easy-to-use concrete admixture, comprising the following steps:

[0045] Step 1: Prepare liquid A, liquid B and water-retaining agent according to the weight ratio. Stir thoroughly during preparation to make the various components fully mixed and set aside;

[0046] Step 2: adding methoxy polyoxyethylene ether (MCPEG), alkylene polyoxyethylene ether (NPEG) and water into a reaction kettle without stirring;

[0047] Step 3: Add ferrous sulfate solution in sequence, and add ammonium persulfate while stirring; after 3-10 minutes, add solution A and solution B dropwise, add solution A dropwise for 40-80 minutes, and solution B dropwise for 50-90 minutes;

[0048] Step 4. The reaction temperature does not exceed 40°, and the temperature is kept for aging for 50-80 minutes; iodothioacetylcholine and water are added;

[0049] Step 5. Add water retaining agent.

[0050] Furthermore, in the method for preparing the low-carbon and easy-to-use concrete admixture, the starting temperature for dropping liquid A and liquid B is both room temperature.

[0051] Furthermore, the preparation temperature of the low-carbon and easy-to-use concrete admixture is controlled within 40°C.

[0052] Furthermore, the ferrous sulfate solution is prepared before use.

[0053] Furthermore, if the concrete transportation distance exceeds 10 kilometers or the construction time exceeds 90 minutes, the application amount of the water retaining agent should be 1.1 to 1.2 times.

[0054] Another object of the present invention is to disclose a use of a low-carbon and easy-to-use concrete admixture in the field of concrete.

[0055] Furthermore, the low-carbon and easy-to-mix coagulant admixture is added during the concrete mixing process. The admixture is added to the water reducer container of the concrete mixing station, input into the mixing station equipment according to the concrete mix ratio, and added automatically.

[0056] Furthermore, the application amount of the low-carbon and easy-to-use concrete admixture is consistent with the water reducing agent ratio in the conventional concrete ratio.

[0057] The low-carbon and easy-to-mix concrete admixture of the present invention, its preparation method and use have the following advantages compared with the prior art:

[0058] 1) The low-carbon and easy-to-mix concrete admixture of the present invention uses multi-carbon-based polycarboxylic acid as the main material, adopts a self-developed concrete admixture reactor, and dry mixes in the first half of the preparation process, which greatly reduces carbon dioxide emissions.

[0059] 2) The low-carbon and easy-to-mix concrete admixture of the present invention is processed and manufactured in a concrete admixture reactor with good heat dissipation and smooth interior, and the manufacturing process is simple and efficient without any pollution emission or residue.

[0060] 3) The use of the low-carbon concrete admixture of the present invention makes the concrete more operable during construction, improves the fluidity of the concrete during the construction process, reduces the energy consumption of the vibrating rod and the energy consumption of the secondary cleaning of the concrete construction tools, and is more low-carbon and environmentally friendly.

[0061] 4) The concrete using the low-carbon and easy-to-use concrete admixture of the present invention has excellent water reduction and slump protection effect, good concrete fluidity, good construction and operation performance, and faster strength improvement.

[0062] In summary, the low-carbon and easy-to-use concrete admixture of the present invention is a concrete admixture with low energy consumption, low emissions, easy operation and easy transportation. DETAILED DESCRIPTION

[0063] The present invention is further described below in conjunction with embodiments:

[0064] Example 1

[0065] This embodiment discloses a low-carbon and easy-to-mix concrete admixture, the preparation process of which is as follows

[0066] Step 1: Prepare liquid A with 35 g of maleic anhydride, 20 g of hydroxyethyl acrylate and 25 g of water;

[0067] Prepare Solution B with 0.25 g of vitamin C, 0.3 g of chlorpyrifos, 1.0 g of mercaptoethanol and 80 g of water;

[0068] Prepare a water-retaining agent according to 1.5 g of xanthan gum and 40 g of water;

[0069] When preparing the above solution, stir it thoroughly to make the various components fully mixed and set aside;

[0070] Step 2: Add 45 g of methoxy polyoxyethylene ether (MCPEG), 300 g of alkylene polyoxyethylene ether (NPEG) and 230 g of water into a reaction kettle without stirring.

[0071] Step 3: Add 1g of 1% ferrous sulfate solution to the bottom of the kettle in sequence, add 2g of 28% ammonium persulfate while stirring, and then add solution A and solution B dropwise after 5 minutes, with solution A dropping for 50 minutes and solution B dropping for 60 minutes;

[0072] Step 4. The reaction temperature does not exceed 40°, and the temperature is kept for 60 minutes; 5 g of iodothioacetylcholine and water are added.

[0073] Step 5. Add water retaining agent to obtain low carbon and easy concrete admixture.

[0074] The concrete mix ratio of the control case is C35 pumped concrete mix ratio, which requires 400g of the admixture with a solid content of 6%. The solid content of this admixture is 52.7%. Take 45.5g of this admixture, add 354.5g of water and mix into the concrete.

[0075] Example 2

[0076] This embodiment discloses a low-carbon and easy-to-mix concrete admixture, the preparation process of which is as follows

[0077] Step 1: Prepare Liquid A with 34 g of maleic anhydride, 19 g of hydroxyethyl acrylate and 26 g of water;

[0078] Prepare Solution B with 0.2g of vitamin C, 0.25g of chlorpyrifos, 0.8g of mercaptoethanol and 70g of water;

[0079] Prepare a water-retaining agent according to 1.4 g of xanthan gum and 40 g of water;

[0080] When preparing, stir thoroughly to mix all components thoroughly and set aside;

[0081] Step 2: Add 50 g of methoxy polyoxyethylene ether (MCPEG), 295 g of alkylene polyoxyethylene ether (NPEG) and 235 g of water into a reaction kettle without stirring.

[0082] Step 3: Add 1 g of 0.8% ferrous sulfate solution to the bottom of the kettle in sequence, add 2 g of 27% ammonium persulfate while stirring, continue stirring for 5 minutes, then dropwise add liquid A and liquid B, add liquid A for 50 minutes, and liquid B for 60 minutes;

[0083] Step 4. The reaction temperature does not exceed 40°, and the temperature is kept for 60 minutes; 5 g of iodothioacetylcholine and water are added.

[0084] Step 5. Add water retaining agent to obtain low carbon and easy concrete admixture.

[0085] The concrete mix ratio of the control case is C35 pumped concrete mix ratio, which requires 400g of the admixture with a solid content of 6%. The solid content of this admixture is 52.6%. Take 45.4g of this admixture, add 354.6g of water and mix into the concrete.

[0086] Comparative Example 1

[0087] The common water reducing agent is a common water reducing agent with BASF formula purchased from outside. After testing, the solid content requirement of the same concrete grade mix ratio is 7%, and 440g of early-strength water reducing agent is required. After the same concrete grade mix ratio, a comparative test is carried out.

[0088] Comparative Example 2

[0089] The slump-preserving water-reducing agent is a slump-preserving water-reducing agent with BASF formula purchased from outside. After testing, the solid content requirement in the same concrete grade mix ratio is 7%, and 440g of early-strength water-reducing agent is required. After the same concrete grade mix ratio, a comparative test is carried out.

[0090] The low-carbon and easy-to-mix concrete admixtures prepared in Example 1 and Example 2 were compared with the ordinary water-reducing agent in Control Example 1 and the slump-preserving water-reducing agent in Control Example 2, and added to concrete of the same grade to test the relevant properties of the concrete. The test data are shown in Table 1.

[0091] Table 1 Performance comparison

[0092]

[0093] It can be seen from Table 1 that the low-carbon and easy-to-use admixtures prepared in Example 1 and Example 2 have excellent initial slurry fluidity, initial expansion 1h slurry fluidity 2h slurry fluidity water reduction rate and compressive strength.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-carbon and easy-to-mix concrete admixture, characterized in that: It is composed of the following components in weight proportion: (1) Base material: 30-60 parts of methoxy polyoxyethylene ether; 270-330 parts of alkylene polyoxyethylene ether; 3-7 parts of iodothioacetylcholine; 0.2-1.7 parts of ferrous sulfate solution; Ammonium persulfate 1.0-3.0 parts; 200-250 parts of water; (2) Liquid A: Maleic anhydride 30-40 parts; 15-25 parts of hydroxyethyl acrylate; 20-30 parts water; (3) Liquid B: Vitamin C 0.1-0.35 parts; 0.20-0.4 parts of chlorpyrifos; 0.5-1.5 parts of mercaptoethanol; 60-90 parts of water; (4) Water-retaining agent: 1-2 parts xanthan gum powder; 30-50 parts water; The low-carbon and easy-to-use concrete admixture is prepared by the following preparation method: Step 1: Prepare liquid A, liquid B and water-retaining agent according to the weight ratio, stir them thoroughly to make the various components fully mixed, and set aside; Step 2: adding methoxy polyoxyethylene ether, alkylene polyoxyethylene ether and water into a reaction kettle without stirring; Step 3: Add ferrous sulfate solution in sequence, and add ammonium persulfate while stirring; after 3-10 minutes, add solution A and solution B dropwise, with solution A being added for 40-80 minutes and solution B being added for 50-90 minutes; the starting temperatures for adding solution A and solution B are both room temperature; Step 4: the reaction temperature does not exceed 40°C, and the temperature is kept for aging for 50-80 minutes; iodothioacetylcholine and water are added; Step 5: Add water retaining agent; The ferrous sulfate solution is prepared on demand; If the concrete transportation distance exceeds 10 kilometers or the construction time exceeds 90 minutes, the amount of water retaining agent applied should be 1.1 to 1.2 times the theoretical amount; The concentration of the ferrous sulfate solution is 0.5-1.5%wt; The concentration of ammonium persulfate is 20-30%wt.

2. Use of the low-carbon and easy-to-mix concrete admixture according to claim 1 in the field of concrete.

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