High impermeability recycled micro powder concrete and preparation method thereof

Abstract

The application relates to the technical field of concrete, and discloses high-permeability-resistant recycled micro-powder concrete and a preparation method thereof. The steps are as follows: 3-(isobutenoyloxy)propyl trimethoxysilane is taken, ethanol aqueous solution is added, the temperature is increased to 40-60 DEG C, and stirring is carried out for 1-2 hours; nano glass beads are added, and the temperature is continuously kept and stirred for 2-4 hours; filtration, washing and drying are carried out, and double-bonded glass beads are obtained; iso-pentenyl polyoxyethylene ether is taken, water is added, and stirring is carried out until the water is uniformly mixed; an initiator is added, and stirring and dissolution are carried out, so that a mixed solution A is obtained; acrylic acid, sodium methallyl sulfonate and double-bonded glass beads are taken, water is added, and stirring is carried out until the water is uniformly mixed; the temperature is increased to 60-70 DEG C, the mixed solution A is added dropwise, the dropwise addition is completed in 2-3 hours, the temperature is increased to 75-80 DEG C, and the temperature is kept for 3-4 hours; the pH value is adjusted to be neutral; filtration and drying are carried out, and modified micro-beads are obtained; coarse aggregate, fine aggregate, recycled micro-powder, fly ash, cement, modified micro-beads, an additive and water are mixed, and high-permeability-resistant recycled micro-powder concrete is obtained.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of concrete, and discloses high-permeability-resistant recycled micro-powder concrete and a preparation method thereof. BACKGROUND

[0002] With the rapid development of the construction industry, the demand for sand and stone resources is also increasing, resulting in the increase of construction cost. The recycled micro-powder obtained by recycling and processing the construction waste mainly composed of waste concrete and then collecting dust can replace part of the raw materials and be used for producing concrete, so that a large amount of resources can be saved.

[0003] The recycled micro-powder is filled in the micro-pores of cement particles and their hydration products, promotes the strength and permeability resistance of the concrete. However, due to the large number of micro-pores in the recycled micro-powder, the free water in the slurry can be absorbed, and part of the water reducing agent can be adsorbed, resulting in the reduction of fluidity and affecting the performance. Therefore, it is of great significance to study the high-strength and high-permeability-resistant recycled micro-powder concrete and the preparation method thereof. SUMMARY

[0004] The application aims to provide high-permeability-resistant recycled micro-powder concrete and a preparation method thereof to solve the problems in the background.

[0005] In order to solve the above technical problems, the application provides the following technical scheme: a preparation method of high-permeability-resistant recycled micro-powder concrete, comprising the following steps: mixing coarse aggregate, fine aggregate, recycled micro-powder, fly ash, cement, modified microbeads, additive, and water to obtain high-permeability-resistant recycled micro-powder concrete.

[0006] The fly ash is Xingda II fly ash with a 45-micron sieve residue of not more than 25%; the recycled micro-powder is obtained by recycling and processing the construction waste mainly composed of waste concrete through a recycling processing production line and then collecting dust, and is from Beijing Urban Green Source Environmental Protection Technology Co., Ltd.; the cement is Zhonglian P.O42.5 cement with a specific surface area of 400 m 2 / kg; the fine aggregate is river sand with a particle size of less than 5 mm and a fineness modulus of 2.6-3.0; and the coarse aggregate is gravel with a particle size of 10-15 mm.

[0007] The preparation of the modified microbeads comprises the following steps: S1-1: 3-(isobutenyl) propyl trimethoxysilane is taken and added into 55wt% ethanol aqueous solution, and then the temperature is increased to 40-60 DEG C for 1-2 h of stirring, nano glass beads are added, and the temperature is continuously kept for 2-4 h of stirring, and then filtration, washing and drying are carried out to obtain double-bond glass beads.

[0008] S1-2: take isopentenyl polyoxyethylene ether, add water and stir until uniform, add initiator APS and stir until dissolved, to obtain mixed solution A; take acrylic acid, sodium methacrylate, double bond glass beads, add water and stir until uniform, heat to 60~70℃, drop mixed solution A, drop for 2~3h, heat to 75~80℃ for 3~4h, adjust pH to neutral, filter and dry, to obtain modified microbeads.

[0009] More preferably, the high anti-permeability recycled micro-powder concrete comprises the following raw materials in parts by mass: 60~80 parts of coarse aggregate, 40~60 parts of fine aggregate, 30~40 parts of recycled micro-powder, 15~20 parts of fly ash, 10~20 parts of cement, 15~20 parts of modified microbeads, 2~3 parts of additive agent, and 10~15 parts of water.

[0010] More preferably, the double bond glass beads comprise the following raw materials in parts by mass: 1~2 parts of 3-(isobutenyl acryloxy) propyl trimethoxysilane, and 10~15 parts of nano glass beads.

[0011] The modified microbeads comprise the following raw materials in parts by mass: 10~15 parts of isopentenyl polyoxyethylene ether, 0.4~0.5 parts of initiator, 1~2 parts of acrylic acid, 4~5 parts of sodium methacrylate, and 80~100 parts of double bond glass beads.

[0012] More preferably, the additive agent comprises a two-arm water reducing agent and sodium ethylenediaminetetraacetate.

[0013] The two-arm water reducing agent is prepared according to the prior art, comprising the following steps: S2-1: take methoxy polyethylene glycol chloride, add dimethyl sulfoxide (DMSO) and stir until dissolved, add potassium carbonate, potassium iodide, and ethanolamine, stir at 80~85℃ for 20~30h under nitrogen protection, remove the solvent, then add dimethyl sulfoxide and stir until uniform, add potassium carbonate, and in dark conditions and under nitrogen protection, add a mixture of acryloyl chloride and dimethyl sulfoxide, react for 20~30h, filter and rotary evaporate to remove impurities, to obtain a two-arm polyoxyethylene ether.

[0014] S2-2: take the two-arm polyoxyethylene ether, add water and stir until uniform, add an initiator and stir until dissolved, to obtain mixed solution B; take acrylic acid and sodium methacrylate, add water and stir until uniform, heat to 60~70℃, drop mixed solution B, drop for 2~3h, heat to 75~80℃ for 3~4h, adjust pH to 7, and remove the solvent, to obtain a two-arm water reducing agent.

[0015] This step takes ethanolamine as the core and performs affinity substitution with methoxy polyethylene glycol chloride. To ensure that both hydrogen atoms on the amine group are substituted, an excess amount of methoxy polyethylene glycol chloride is used. After the amine group of ethanolamine is completely substituted, a carbon-carbon double bond is introduced through acryloyl chloride, to obtain a two-arm polyoxyethylene ether.

[0016] More preferably, the mass ratio of the two-arm water reducing agent and sodium ethylenediaminetetraacetate is (1-3):1.

[0017] More preferably, the two-arm polyoxyethylene ether comprises the following raw materials in mass fraction: 120-150 parts of methoxy polyethylene glycol chloride, 2-3 parts of ethanolamine, 8-15 parts of acryloyl chloride.

[0018] The two-arm water reducing agent comprises the following raw materials in mass fraction: 10-15 parts of two-arm polyoxyethylene ether, 0.4-0.5 parts of initiator, 1-2 parts of acrylic acid, and 4-5 parts of sodium methallyl sulfonate.

[0019] More preferably, the isopentenyl polyoxyethylene ether is TPEG2400, and the methoxy polyethylene glycol chloride has a molecular weight of 1k.

[0020] Compared with the prior art, the beneficial effects achieved by the present application are that the addition of the recycled micro powder promotes the performance of the concrete, but due to the large number of micro pores inside, the recycled micro powder can absorb water and water reducing agent in the slurry, and the recycled micro powder has a layered structure, which is difficult to provide rolling lubrication, resulting in reduced fluidity and affecting the overall performance.

[0021] Therefore, the present application introduces modified micro beads, uses nano glass beads as raw materials, increases rolling lubrication, and has a small particle size, which forms a continuous grading with other particulate matter, so that the particles are more closely packed. The nano glass beads are modified to have water reducing agent grafted on the surface, part of which is adsorbed by the recycled micro powder to improve the bonding force between the recycled micro powder and the modified micro beads, and the other part is used to improve the dispersibility of the whole. At the same time, the present application also introduces an additive, the two-arm water reducing agent has a similar structure to the water reducing agent grafted on the surface of the modified micro beads, but has greater steric hindrance and is not easily adsorbed by the recycled micro powder, so it can provide good effect of improving fluidity. Sodium ethylenediaminetetraacetate is a small molecule additive that has complexing properties for metal ions, which makes the hydration products disperse rapidly, thereby enhancing the strength of the concrete.

[0022] In summary, the present application improves the problem of reduced fluidity caused by the introduction of recycled micro powder by introducing modified micro beads and additives, and ultimately obtains a high-strength and high-impervious concrete material. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] It should be noted that there is no special restriction on the purchase manufacturer of all raw materials involved in the present application, which exemplarily includes: fly ash is Xingda II fly ash, 45 mu m sieve residue is not more than 25%; recycled powder is building waste mainly from waste concrete after processing by a recycling processing line, which is obtained after dust collection, from Beijing Urban Green Source Environmental Protection Technology Co., Ltd.; the cement is Zhonglian P.O42.5 cement, the specific surface area is 400 m 2 / kg; the fine aggregate is river sand, the particle size is less than 5 mm, and the fineness modulus is 2.6-3.0; the coarse aggregate is gravel, the particle size is 10-15 mm;

[0025] Ethanol (CAS: 64-17-5); dimethyl sulfoxide (DMSO, dimethyl sulfoxide); 3-(isobutenoyloxy) propyl trimethoxysilane (CAS: 2530-85-0); nano glass beads (sh-516, Guangzhou Shuanghong Building Material Co., Ltd.); isopentenyl polyoxyethylene ether (TPEG2400, Wuhan Kanos); initiator APS (ammonium persulfate, CAS: 7727-54-0); sodium ethylenediaminetetraacetate (ethylenediaminetetraacetic acid disodium salt dihydrate, S30026, Shanghai Yuan Ye); methoxy polyethylene glycol chloride (Tansh, molecular weight 1k); potassium carbonate (anhydrous potassium carbonate, Shanghai Yuan Ye); potassium iodide (S30393, Shanghai Yuan Ye); ethanolamine (CAS: 141-43-5); acryloyl chloride (CAS: 814-68-6);

[0026] Unless otherwise specified, the following are mass parts, mass ratio;

[0027] Example 1: Step one: S1-1: take 1.5 parts of 3-(isobutenoyloxy) propyl trimethoxysilane, add 50 parts of 55wt% ethanol aqueous solution, heat to 50℃ and stir for 1h, add 10 parts of nano glass beads, continue to heat and stir for 4h, filter, wash and dry to obtain double bond modified glass beads;

[0028] S1-2: take 12 parts of isopentenyl polyoxyethylene ether, add 60 parts of water and stir uniformly, add 0.4 parts of initiator APS and stir to dissolve to obtain a mixed solution A; take 1.5 parts of acrylic acid, 4.5 parts of sodium methacrylate, 100 parts of double bond modified glass beads, add 200 parts of water, stir uniformly, heat to 60℃, and drop the mixed solution A, 2h drop completion, heat to 75℃ and keep for 4h, adjust pH to 7, filter and dry to obtain modified microbeads;

[0029] Step two: S2-1: take 120 parts of methoxy polyethylene glycol chloride, add 100 parts of DMSO, stir and dissolve, add 28 parts of potassium carbonate, 0.8 parts of potassium iodide, 2.5 parts of ethanolamine, nitrogen protection, 80℃ stirring for 24h, remove the solvent, add 80 parts of DMSO and stir evenly, then add 25 parts of potassium carbonate, use ice bath, in dark condition and nitrogen protection, add 12 parts of acryloyl chloride and 20 parts of DMSO mixture, add time 30min, reaction 24h, filter, rotary evaporation, remove impurities, get two arm polyoxyethylene ether;

[0030] S2-2: take 13 parts of two arm polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve, get mixed solution B; take 1.5 parts of acrylic acid, 4.5 parts of sodium methacrylate, add 30 parts of water, stir evenly, heat to 60℃, drop mixed solution B, 2h drop completion, heat to 75℃ for 4h, adjust pH to 7, remove the solvent, get two arm water reducing agent;

[0031] S2-3: mix two arm water reducing agent and sodium ethylenediaminetetraacetate with mass ratio 2:1, get admixture;

[0032] Step three: mix 70 parts of coarse aggregate, 50 parts of fine aggregate, 35 parts of recycled powder, 16 parts of fly ash, 18 parts of cement, 18 parts of modified micro bead, 2 parts of admixture, 10 parts of water, get high impermeability recycled powder concrete.

[0033] Example 2: step one: S1-1: take 1.5 parts of 3-(isobutenoyloxy) propyl trimethoxysilane, add 50 parts of 55wt% ethanol aqueous solution, heat to 50℃ stirring for 1h, add 10 parts of nano glass bead, continue to heat and stir for 4h, filter, wash, dry, get double bond glass bead;

[0034] S1-2: take 10 parts of isopentenyl polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve, get mixed solution A; take 1 part of acrylic acid, 4 parts of sodium methacrylate, 80 parts of double bond glass bead, add 200 parts of water, stir evenly, heat to 60℃, drop mixed solution A, 2h drop completion, heat to 75℃ for 4h, adjust pH to 7, filter, dry, get modified micro bead;

[0035] Step two: S2-1: take 120 parts of methoxy polyethylene glycol chloride, add 100 parts of DMSO, stir and dissolve, add 30 parts of potassium carbonate, 0.8 parts of potassium iodide, 2.5 parts of ethanolamine, nitrogen protection, 80℃ stirring for 24h, remove the solvent, add 80 parts of DMSO and stir evenly, then add 30 parts of potassium carbonate, use ice bath, in the dark and nitrogen protection, add 15 parts of acryloyl chloride and 20 parts of DMSO mixture, add time 30min, reaction 24h, filter, rotary evaporation, remove impurities, get two arm polyoxyethylene ether;

[0036] S2-2: take 10 parts of two arm polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve, get mixed solution B; take 1 part of acrylic acid, 4 parts of sodium methacrylate, add 30 parts of water, stir evenly, heat to 60℃, drop mixed solution B, 2h drop completion, heat to 75℃ for 4h, adjust pH to 7, remove the solvent, get two arm water reducing agent;

[0037] S2-3: mix two arm water reducing agent and sodium ethylenediaminetetraacetate with mass ratio of 2:1, get admixture;

[0038] Step three: mix 60 parts of coarse aggregate, 40 parts of fine aggregate, 30 parts of recycled powder, 15 parts of fly ash, 12 parts of cement, 20 parts of modified micro bead, 2 parts of admixture, 10 parts of water, get high impermeability recycled powder concrete.

[0039] Example 3: step one: S1-1: take 1.5 parts of 3-(isobutenoyl) propyl trimethoxysilane, add 50 parts of 55wt% ethanol aqueous solution, heat to 50℃ stirring for 1h, add 10 parts of nano glass beads, continue to heat and stir for 4h, filter, wash, dry, get double bond glass beads;

[0040] S1-2: take 15 parts of isopentenyl polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve, get mixed solution A; take 2 parts of acrylic acid, 5 parts of sodium methacrylate, 100 parts of double bond glass beads, add 200 parts of water, stir evenly, heat to 60℃, drop mixed solution A, 2h drop completion, heat to 75℃ for 4h, adjust pH to 7, filter, dry, get modified micro bead;

[0041] Step two: S2-1: take 120 parts of methoxy polyethylene glycol chloride, add 100 parts of DMSO, stir and dissolve, add 25 parts of potassium carbonate, 0.8 parts of potassium iodide, 2.5 parts of ethanolamine, nitrogen protection, 80℃ stirring for 24h, remove the solvent, add 80 parts of DMSO and stir evenly, then add 30 parts of potassium carbonate, use ice block for ice bath, in dark condition and nitrogen protection, add 15 parts of acryloyl chloride and 20 parts of DMSO mixture, add time 30min, reaction 24h, suction filtration, rotary evaporation, remove impurities, get two arm polyoxyethylene ether;

[0042] S2-2: take 15 parts of two arm polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve, get mixed solution B; take 2 parts of acrylic acid, 5 parts of sodium methacrylate, add 30 parts of water, stir evenly, heat to 60℃, drop mixed solution B, 2h drop completion, heat to 75℃ for 4h, adjust pH to 7, remove the solvent, get two arm water reducing agent;

[0043] S2-3: mix two arm water reducing agent and sodium ethylenediaminetetraacetate with mass ratio 2:1, get admixture;

[0044] Step three: mix 80 parts of coarse aggregate, 60 parts of fine aggregate, 40 parts of recycled powder, 20 parts of fly ash, 20 parts of cement, 20 parts of modified micro bead, 3 parts of admixture, 15 parts of water, get high impermeability recycled powder concrete.

[0045] Comparative example 1 (use nano glass bead instead of modified micro bead, the rest of the method steps are consistent with example 1): step one: use nano glass bead instead of modified micro bead;

[0046] Step two: S2-1: take 120 parts of methoxy polyethylene glycol chloride, add 100 parts of DMSO, stir and dissolve, add 25 parts of potassium carbonate, 0.8 parts of potassium iodide, 2.5 parts of ethanolamine, nitrogen protection, 80℃ stirring for 24h, remove the solvent, add 80 parts of DMSO and stir evenly, then add 30 parts of potassium carbonate, use ice block for ice bath, in dark condition and nitrogen protection, add 15 parts of acryloyl chloride and 20 parts of DMSO mixture, add time 30min, reaction 24h, suction filtration, rotary evaporation, remove impurities, get two arm polyoxyethylene ether;

[0047] S2-2: take 15 parts of two arm polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve, get mixed solution B; take 2 parts of acrylic acid, 5 parts of sodium methacrylate, add 30 parts of water, stir evenly, heat to 60℃, drop mixed solution B, 2h drop completion, heat to 75℃ for 4h, adjust pH to 7, remove the solvent, get two arm water reducing agent;

[0048] S2-3: mixing the two-arm water reducing agent and sodium ethylenediaminetetraacetate with a mass ratio of 2:1 to obtain an admixture;

[0049] Step three: mixing 70 parts of coarse aggregate, 50 parts of fine aggregate, 35 parts of recycled micro powder, 16 parts of fly ash, 18 parts of cement, 18 parts of nano glass beads, 2 parts of admixture, and 10 parts of water to obtain high impermeability recycled micro powder concrete.

[0050] Comparative Example 2 (using glass fiber (diameter 0.1-0.2 mm, length 10-15 mm) instead of nano glass beads, and the rest of the method steps are the same as Example 1): Step one: using glass fiber (diameter 0.1-0.2 mm, length 10-15 mm) instead of nano glass beads to prepare modified fiber instead of modified microbeads: taking 1.5 parts of 3-(isobutenyl) propyl trimethoxysilane, adding 50 parts of 55wt% ethanol aqueous solution, heating to 50℃ and stirring for 1h, adding 10 parts of glass fiber, continuing to heat and stir for 4h, filtering, washing and drying to obtain double bond glass fiber;

[0051] Taking 12 parts of isopentenyl polyoxyethylene ether, adding 60 parts of water and stirring uniformly, adding 0.4 parts of initiator APS and stirring to dissolve to obtain a mixed solution A; taking 1.5 parts of acrylic acid, 4.5 parts of sodium methacrylate sulfonate, 100 parts of double bond glass fiber, adding 200 parts of water and stirring uniformly, heating to 60℃, adding the mixed solution A dropwise, and adding dropwise for 2h, heating to 75℃ and keeping for 4h, adjusting the pH to 7, filtering and drying to obtain modified fiber;

[0052] Step two: S2-1: taking 120 parts of methoxy polyethylene glycol chloride, adding 100 parts of DMSO and stirring to dissolve, adding 28 parts of potassium carbonate, 0.8 parts of potassium iodide and 2.5 parts of ethanolamine, stirring at 80℃ for 24h under nitrogen protection, removing the solvent, adding 80 parts of DMSO and stirring uniformly, adding 25 parts of potassium carbonate, using ice block for ice bath, adding a mixture of 12 parts of acryloyl chloride and 20 parts of DMSO under dark condition and nitrogen protection, adding for 30min, reacting for 24h, and removing impurities by suction filtration and rotary evaporation to obtain two-arm polyoxyethylene ether;

[0053] S2-2: taking 13 parts of two-arm polyoxyethylene ether, adding 60 parts of water and stirring uniformly, adding 0.4 parts of initiator APS and stirring to dissolve to obtain a mixed solution B; taking 1.5 parts of acrylic acid and 4.5 parts of sodium methacrylate sulfonate, adding 30 parts of water and stirring uniformly, heating to 60℃, adding the mixed solution B dropwise, and adding dropwise for 2h, heating to 75℃ and keeping for 4h, adjusting the pH to 7, and removing the solvent to obtain a two-arm water reducing agent;

[0054] S2-3: mixing the two-arm water reducing agent and sodium ethylenediaminetetraacetate with a mass ratio of 2:1 to obtain an admixture;

[0055] Step three: 70 parts of coarse aggregate, 50 parts of fine aggregate, 35 parts of recycled micro powder, 16 parts of fly ash, 18 parts of cement, 18 parts of modified fiber, 2 parts of additive, 10 parts of water are mixed to obtain high impermeability recycled micro powder concrete.

[0056] Comparative example 3 (using water reducing agent instead of two-arm water reducing agent, and the rest of the method steps are consistent with example 1): step one: S1-1: take 1.5 parts of 3-(isobutenoyloxy) propyl trimethoxysilane, add 50 parts of 55wt% ethanol aqueous solution, heat to 50℃ and stir for 1h, add 10 parts of nano glass beads, continue to heat and stir for 4h, filter, wash and dry to obtain double bond glass beads;

[0057] S1-2: take 12 parts of isopentenyl polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir to dissolve, and obtain a mixed solution A; take 1.5 parts of acrylic acid, 4.5 parts of sodium methyl methacrylate, 100 parts of double bond glass beads, add 200 parts of water, stir evenly, heat to 60℃, drop the mixed solution A, 2h drop completion, heat to 75℃ and keep for 4h, adjust pH to 7, filter and dry to obtain modified microbeads;

[0058] Step two: prepare water reducing agent instead of two-arm water reducing agent in additive: take 12 parts of isopentenyl polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir to dissolve, and obtain a mixed solution A; take 1.5 parts of acrylic acid, 4.5 parts of sodium methyl methacrylate, add 30 parts of water, stir evenly, heat to 60℃, drop the mixed solution A, 2h drop completion, heat to 75℃ and keep for 4h, adjust pH to 7, remove the solvent to obtain water reducing agent;

[0059] Mix water reducing agent and sodium ethylenediaminetetraacetate with a mass ratio of 2:1 to obtain additive;

[0060] Step three: 70 parts of coarse aggregate, 50 parts of fine aggregate, 35 parts of recycled micro powder, 16 parts of fly ash, 18 parts of cement, 18 parts of modified microbeads, 2 parts of additive, 10 parts of water are mixed to obtain high impermeability recycled micro powder concrete.

[0061] Comparative example 4 (using two-arm water reducing agent as additive, and the rest of the method steps are consistent with example 1): step one: S1-1: take 1.5 parts of 3-(isobutenoyloxy) propyl trimethoxysilane, add 50 parts of 55wt% ethanol aqueous solution, heat to 50℃ and stir for 1h, add 10 parts of nano glass beads, continue to heat and stir for 4h, filter, wash and dry to obtain double bond glass beads;

[0062] S1-2: Take 12 parts of isopentenyl polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve to obtain a mixed solution A; take 1.5 parts of acrylic acid, 4.5 parts of sodium methacrylate, 100 parts of double bond glass beads, add 200 parts of water, stir evenly, heat to 60℃, drop the mixed solution A, drop for 2h, heat to 75℃ for 4h, adjust pH to 7, filter and dry to obtain modified microbeads;

[0063] Step two: directly use two-arm water-reducing agent as admixture: take 120 parts of methoxy polyethylene glycol chloride, add 100 parts of DMSO, stir and dissolve, add 28 parts of potassium carbonate, 0.8 parts of potassium iodide, 2.5 parts of ethanolamine, under nitrogen protection, stir at 80℃ for 24h, remove the solvent, add 80 parts of DMSO and stir evenly, then add 25 parts of potassium carbonate, use ice block for ice bath, under dark condition and nitrogen protection, add a mixture of 12 parts of acryloyl chloride and 20 parts of DMSO, add for 30min, react for 24h, filter and rotary evaporate to remove impurities, obtain two-arm polyoxyethylene ether;

[0064] Take 13 parts of two-arm polyoxyethylene ether, add 60 parts of water and stir evenly, add 0.4 parts of initiator APS, stir and dissolve to obtain a mixed solution B; take 1.5 parts of acrylic acid, 4.5 parts of sodium methacrylate, add 30 parts of water, stir evenly, heat to 60℃, drop the mixed solution B, drop for 2h, heat to 75℃ for 4h, adjust pH to 7, remove the solvent to obtain two-arm water-reducing agent, which is used as admixture;

[0065] Step three: mix 70 parts of coarse aggregate, 50 parts of fine aggregate, 35 parts of recycled micro powder, 16 parts of fly ash, 18 parts of cement, 18 parts of modified microbeads, 2 parts of admixture, and 10 parts of water to obtain high impermeability recycled micro powder concrete.

[0066] Performance test: take the high impermeability recycled micro powder concrete prepared in examples 1-3 and comparative examples 1-4; (1) test 28d compressive strength according to GB / T50081-2002; (2) test impermeability according to GB / T50082-2009; (3) test expansion degree according to GB / T50080-2016 to evaluate the fluidity; see table 1 for details;

[0067] Table 1:

[0068]

[0069] Conclusion: The performance of the comparative example 1 is obviously decreased by using nano glass beads instead of modified micro beads without modification; the performance of the comparative example 2 is decreased due to the change of morphology and fluidity; the performance of the comparative example 3 is decreased due to the decrease of steric hindrance; the performance of the comparative example 4 is obviously worse than the embodiment without adding small molecule additive sodium ethylenediaminetetraacetate; in conclusion, the high impermeability recycled micro powder concrete prepared by the application has good strength and impermeability.

[0070] Finally, it should be noted that: the above only for the preferred embodiments of the application and not for limiting the application, although the application has been described in detail with reference to the foregoing examples, for those skilled in the art, it still can be modified, or equivalent replacement of part of the technical features recorded in the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A method for preparing highly impermeable recycled micro-powder concrete, characterized in that: Includes the following steps: Step 1: S1-1: Take 3-(isobutenoyloxy)propyltrimethoxysilane, add it to an aqueous ethanol solution, heat to 40~60℃ and stir for 1~2h, add nano glass beads, continue to keep warm and stir for 2~4h, filter, wash and dry to obtain double-bonded glass beads. S1-2: Take isopentenyl polyoxyethylene ether, add it to water and stir evenly, add initiator and stir to dissolve, to obtain mixed solution A; take acrylic acid, sodium methacrylate sulfonate and double-bonded glass beads, add them to water and stir evenly, heat to 60~70℃, add mixed solution A dropwise, and finish adding in 2~3 hours, heat to 75~80℃ and keep warm for 3~4 hours, adjust the pH to neutral, filter and dry to obtain modified microbeads; Step 2: The two-arm water-reducing agent and sodium ethylenediaminetetraacetate are compounded to obtain an additive; the preparation of the two-arm water-reducing agent includes the following steps: S2-1: Take methoxy polyethylene glycol chloride, add dimethyl sulfoxide and stir to dissolve, add potassium carbonate, potassium iodide and ethanolamine, stir at 80~85℃ for 20~30h under nitrogen protection, remove the solvent, add dimethyl sulfoxide and stir evenly, add potassium carbonate, in an ice bath and under dark conditions and nitrogen protection, add a mixture of acryloyl chloride and dimethyl sulfoxide, react for 20~30h, filter and rotary evaporate to remove impurities, and obtain two-arm polyoxyethylene ether; S2-2: Take two-arm polyoxyethylene ether, add it to water and stir evenly, add initiator, stir to dissolve, and obtain mixed solution B; take acrylic acid and sodium methacrylate, add them to water, stir evenly, heat to 60~70℃, add mixed solution B dropwise, and finish adding in 2~3 hours, heat to 75~80℃ and keep warm for 3~4 hours, adjust pH to 7, remove solvent, and obtain two-arm water-reducing agent; Step 3: Mix coarse aggregate, fine aggregate, recycled micro powder, fly ash, cement, modified microspheres, admixtures, and water to obtain high impermeability recycled micro powder concrete.

2. The method for preparing high-permeability recycled micro-powder concrete according to claim 1, characterized in that: The high impermeability recycled micro-powder concrete comprises the following raw materials, by weight: 60-80 parts coarse aggregate, 40-60 parts fine aggregate, 30-40 parts recycled micro-powder, 15-20 parts fly ash, 10-20 parts cement, 15-20 parts modified microspheres, 2-3 parts admixture, and 10-15 parts water.

3. The method for preparing highly impermeable recycled micro-powder concrete according to claim 1, characterized in that: The double-bonded glass beads comprise the following raw materials, by mass: 1-2 parts of 3-(isobutenoyloxy)propyltrimethoxysilane, and 10-15 parts of nano glass beads; The modified microspheres comprise the following raw materials, by mass: 10-15 parts isopentenyl polyoxyethylene ether, 0.4-0.5 parts initiator, 1-2 parts acrylic acid, 4-5 parts sodium methacrylate sulfonate, and 80-100 parts double-bonded glass beads.

4. The method for preparing high-permeability recycled micro-powder concrete according to claim 1, characterized in that: The mass ratio of the two-arm water-reducing agent to sodium ethylenediaminetetraacetate is (1~3):

1.

5. The method for preparing high-permeability recycled micro-powder concrete according to claim 1, characterized in that: The two-arm polyoxyethylene ether comprises the following raw materials, by weight: 120-150 parts methoxy polyethylene glycol chloride, 2-3 parts ethanolamine, and 8-15 parts acryloyl chloride; the two-arm water-reducing agent comprises the following raw materials, by weight: 10-15 parts two-arm polyoxyethylene ether, 0.4-0.5 parts initiator, 1-2 parts acrylic acid, and 4-5 parts sodium methacrylate sulfonate.

6. The method for preparing high-permeability recycled micro-powder concrete according to claim 1, characterized in that: The isopentenyl polyoxyethylene ether is TPEG2400.

7. The method for preparing high-permeability recycled micro-powder concrete according to claim 1, characterized in that: The methoxy polyethylene glycol chloride has a molecular weight of 1k.

8. Concrete prepared by the method for preparing high impermeability recycled micro-powder concrete according to any one of claims 1 to 7.

Images