CN112047663A - Concrete additive special for shield segment and preparation method thereof - Google Patents
Concrete additive special for shield segment and preparation method thereof Download PDFInfo
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- CN112047663A CN112047663A CN202010978536.6A CN202010978536A CN112047663A CN 112047663 A CN112047663 A CN 112047663A CN 202010978536 A CN202010978536 A CN 202010978536A CN 112047663 A CN112047663 A CN 112047663A
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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
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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
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
- C04B24/26—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C04B24/2688—Copolymers containing at least three different monomers
- C04B24/2694—Copolymers containing at least three different monomers containing polyether side chains
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
- C08F283/06—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals
- C08F283/065—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals on to unsaturated polyethers, polyoxymethylenes or polyacetals
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Abstract
The special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate superplasticizer, an early-strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 25-45% of an early-strength polycarboxylic acid water reducing agent, 0-12% of an early-strength agent, 0.5-3% of a state regulator, 0.05-0.2% of a defoaming agent, 0.01-0.1% of an air entraining agent and the balance of water. The early-strength polycarboxylate superplasticizer is an early-strength polycarboxylate superplasticizer with the side chain molecular weight of 4000-6000. The preparation method comprises the following steps: and sequentially adding the early strength agent, water and the defoaming agent into a stirring kettle, uniformly stirring, adding the early strength polycarboxylate water reducing agent, the state regulator and the defoaming agent, continuously stirring, and finally adding the air entraining agent and uniformly stirring to obtain the additive. The special concrete additive for the shield segment can meet the requirement that the steam curing strength of the shield segment is more than 20MPa for 8 hours, and reduces bubbles and color difference on the appearance surface of the shield segment.
Description
Technical Field
The invention relates to a concrete additive, in particular to a concrete additive special for shield segments. Belongs to the technical field of building material chemical additives. The invention also relates to a preparation method of the concrete additive, in particular to a preparation method of the concrete additive special for the shield segment.
Background
With the continuous improvement of the urbanization level in China, the urban traffic congestion problem is increasingly prominent, and the construction of subways gradually becomes the urban development trend. At present, the most widely applied subway construction method at home and abroad is a shield construction method, shield segments are used as main assembly components for shield construction, and the quality of the shield segments is directly related to the overall quality and safety of a tunnel. At present, the most common duct piece in China is a precast concrete duct piece, and a polycarboxylic acid additive is usually adopted in the precast concrete duct piece. In order to improve the production efficiency and the turnover rate of a steel die, domestic manufacturers adopt a steam curing process, the strength of concrete is required to reach more than 20Mpa after the steam curing is carried out for 8 hours, the requirements of the manufacturers on the appearance of the duct pieces are stricter, the problems of air bubbles and color difference on the surfaces of the duct pieces become important concerns, and higher requirements are provided for duct piece concrete additives. If the early strength function of the additive under the steam curing condition is adopted, the early strength of the concrete is improved without influencing the later strength; the concrete has the function of adjusting the state of the concrete under low slump, improves the workability of the concrete, reduces color difference and is beneficial to quickly removing air bubbles. At present, the technical problems are very troublesome for concrete additive manufacturers, especially the problem of appearance bubbles, complex concrete sandstone materials and great difference of appearance bubbles. Therefore, the development of a concrete additive special for the duct piece is in great tendency.
The inventors searched the following related patent documents: CN103922631A discloses a concrete additive and a preparation method thereof, wherein the concrete comprises the following components in parts by weight: 19-23 parts of a polycarboxylic acid water reducing agent, 5-10 parts of an accelerator, 7-11 parts of diethylenetriamine, 4-8 parts of triethanolamine, 2-4 parts of nitrite, 1.5-2.5 parts of calcium carbonate, 1-3 parts of calcium chloride, 0.5-1.5 parts of urea and 2-4 parts of ethylene glycol. CN102372461A discloses a concrete additive comprising hydrophilic colloid extracted from plants and air entraining agent. The hydrophilic colloid can reduce the sensitivity of the polycarboxylate water reducer, enhance the water retention capacity of concrete and improve slump retention; and meanwhile, the air entraining agent is introduced, so that the slump retaining property of the concrete can be further improved, the fluidity of the concrete is increased, and the using amount of the polycarboxylic acid water reducing agent is reduced.
The concrete additive can meet the requirement that the steam curing strength of the shield segment is more than 20MPa for 8 hours, the problems of bubbles and color difference on the appearance surface of the shield segment are obviously improved, and a specific guidance scheme is not provided.
Disclosure of Invention
The invention aims to solve the technical problem of providing a special concrete additive for shield segments, which can meet the requirement that the steam curing strength of the shield segments is more than 20MPa for 8 hours and obviously improve the problems of bubbles and chromatic aberration on the appearance surfaces of the shield segments.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylic acid water reducing agent, an early-strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 25-45% of an early-strength polycarboxylic acid water reducing agent, 0-12% of an early-strength agent, 0.5-3% of a state regulator, 0.05-0.2% of a defoaming agent, 0.01-0.1% of an air entraining agent and the balance of water, wherein the sum of the mass percentages of the components is 100%. The early-strength polycarboxylate superplasticizer is an early-strength polycarboxylate superplasticizer with the side chain molecular weight of 4000-6000. The (concrete) state regulator is prepared from the following raw materials in parts by weight: 18.0 parts of acrylamide monomer, 1.5 parts of acrylic monomer, 1 part of vinyl acetate, 3.0 parts of polyether monomer, 3.0 parts of methyl allyl polyoxyethylene ether, wherein the weight average molecular weight of the methyl allyl polyoxyethylene ether is 1000, 0.04 part of initiator, 8.2 parts of alkali liquor, namely NaOH aqueous solution with the mass percentage concentration of 30%, and 1400 parts of deionized water; the initiator is a redox system, the oxidant is 0.02 part of ammonium persulfate, and the reducing agent is 0.02 part of sodium bisulfite. The preparation method of the state regulator comprises the following process steps: dispersing hydrophobic monomers in 140 parts of deionized water by using an ultrasonic disperser to obtain dispersion liquid, pouring the dispersion liquid into a three-neck flask, adding acrylamide monomers, acrylic monomers and polyether monomers into the three-neck flask, stirring, heating to 45 ℃, adding ammonium persulfate and sodium bisulfite into the three-neck flask, and carrying out heat preservation reaction for 4.5 hours to obtain an intermediate product; and secondly, adding the rest deionized water into the intermediate product to dissolve and dilute the intermediate product, and then adding alkali liquor to neutralize the intermediate product to obtain a final product, namely the state regulator. The early strength agent is one or a combination (mixture) of more of inorganic salts, diethanol amine, triethanol amine, triisopropanol amine, calcium nitrate, calcium chloride, lithium sulfate and sodium sulfate in organic matters. The preparation method of the concrete additive special for the shield segments comprises the following process steps of sequentially adding the early strength agent, water and the defoaming agent into a stirring kettle according to a determined proportion, uniformly stirring, adding the early strength polycarboxylic acid water reducing agent, the state regulator and the defoaming agent, continuously stirring, and finally adding the air entraining agent and uniformly stirring to obtain the concrete additive special for the shield segments.
In the above technical scheme, a preferable technical scheme may be that the early strength polycarboxylate water reducer is one or a mixture of more of comb-structured polymers with side chain molecular weights of 4000, 5000 and 6000 polyether macromonomers (prenyl alcohol polyoxyethylene ether) and acrylic acid polymerized by free radicals. The early-strength polycarboxylate superplasticizer is a commercial product or is prepared by adopting the prior art. The defoaming agent is one or a combination of more of dimethyl silicone defoaming agent, polyether modified silicone defoaming agent (DT-650 polyether modified silicone defoaming agent, produced by south China sea field chemical Co., Ltd., Fushan City) and acetylene glycol defoaming agent (mixture, and the mixture ratio is arbitrary when the mixture is combined); the air entraining agent is one or a combination of several of triterpenoid saponin, sodium dodecyl sulfate (K12 sodium dodecyl sulfate), fatty alcohol-polyoxyethylene ether sodium sulfate (AES) and alpha-sodium alkenyl sulfonate (AOS) (mixture, and the proportion is optional when the mixture is combined).
In the above technical solution, a preferable technical solution may also be that the concrete additive special for the shield segment is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 4000 molecular weight, an early-strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and the mass percentages of the components are as follows: 35 percent of early-strength polycarboxylate water reducing agent with the side chain of 4000 molecular weight, 6 percent of early-strength agent namely calcium nitrate, 0.5 percent of state regulator, 0.08 percent of defoaming agent namely dimethyl silicone oil, 0.02 percent of air entraining agent namely sodium dodecyl sulfate, and the balance of water, wherein the sum of the mass percent of the components is 100 percent. The preparation method of the concrete additive special for the shield segment comprises the following process steps of adding 60 parts of calcium nitrate and 584 parts of water into a 2L stirring kettle according to a determined proportion, stopping stirring after uniform stirring, continuously adding 350 parts of the early-strength polycarboxylic acid water reducing agent, 5 parts of the state regulator and 0.8 part of dimethyl silicone oil (dimethyl silicone oil defoaming agent) into the stirring kettle, continuously stirring, finally adding 0.2 part of sodium dodecyl sulfate, and uniformly stirring to obtain the concrete additive special for the shield segment.
Among the above technical solutions, preferred technical solutions can also be embodiments 2 to 8.
In the invention, the early strength principle of the early strength polycarboxylate superplasticizer is as follows: compare conventional 2400 side chain molecular weight's polycarboxylate water reducing agent, longer side chain molecular weight's water reducing agent, under the roughly the same circumstances of water reducing agent weight average molecular weight, long side chain molecular weight's water reducing agent has very short main chain, and the molecular structure is similar to become T type structure by comb type structure, and side chain length is far greater than main chain length, and the interval is great between the side chain, when having stronger steric hindrance dispersion effect, long side chain can let moisture normally get into the cement granule and guarantee normal cement hydration. Meanwhile, carboxyl on the main chain and a calcium ion complex in the solution have higher solubility, thereby providing conditions for continuous hydration of cement. The electron scanning electron microscope shows that the hydration of early tricalcium aluminate is influenced by longer side chains, the formation of calcium hydroxide and ettringite is accelerated, and the early mechanical property of concrete is improved.
The invention has the beneficial effects that: the selection of early strong class water-reducing agent makes the section of jurisdiction can reach the strength requirement under the condition of evaporating to foster, the reasonable collocation of air entraining agent and defoaming agent simultaneously can reach that there is reasonable microcosmic microbubble in the concrete inside, it is abundant to make the slurry, concrete viscosity is lower, under the condition in vibration field, the slurry can be rapidly the full template interface of spreading, the bubble can rise the migration fast simultaneously and get rid of to the concrete upper surface, the bubble number on the interface that makes concrete and template contact is few and little, the outward appearance problem of section of jurisdiction obtains fine solution.
Tests prove that the special concrete additive for the shield segment can meet the requirement that the steam curing strength of the shield segment is more than 20MPa for 8 hours, and reduces bubbles and color difference on the appearance surface of the shield segment. The preparation method is simple in preparation process, low in production cost and suitable for industrial production.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all 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.
Example 1: the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 4000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 35 percent of early-strength polycarboxylate water reducing agent with the side chain of 4000 molecular weight, 6 percent of early-strength agent namely calcium nitrate, 0.5 percent of state regulator, 0.08 percent of defoaming agent namely dimethyl silicone oil, 0.02 percent of air entraining agent namely sodium dodecyl sulfate, and the balance of water, wherein the sum of the mass percent of the components is 100 percent. The preparation method of the concrete additive special for the shield segment comprises the following process steps of adding 60 parts of calcium nitrate and 584 parts of water into a 2L stirring kettle according to a determined proportion, stopping stirring after uniform stirring, continuously adding 350 parts of the early-strength polycarboxylic acid water reducing agent, 5 parts of the state regulator and 0.8 part of dimethyl silicone oil (dimethyl silicone oil defoaming agent) into the stirring kettle, continuously stirring, finally adding 0.2 part of sodium dodecyl sulfate, and uniformly stirring to obtain the concrete additive special for the shield segment.
Example 2: the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 4000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 38 percent of early-strength polycarboxylate water reducing agent with the side chain of 4000 molecular weight, 9 percent of early strength agent (namely 6 percent of calcium nitrate and 3 percent of triethanolamine), 2 percent of state regulator, 0.08 percent of defoaming agent (polyether modified organosilicon defoaming agent can be DT-650 polyether modified organosilicon defoaming agent produced by south China sea field chemical limited company in Fushan City), 0.02 percent of air entraining Agent (AOS), and the balance of water, wherein the early strength agent is the combination of 6 percent of calcium nitrate and 3 percent of triethanolamine; the sum of the mass percentages of the components is 100 percent. The preparation method of the special concrete additive for the shield segments comprises the following process steps of adding 60 parts of calcium nitrate and 30 parts of triethanolamine into a 2L stirring kettle according to a determined proportion, adding 509 parts of water, stopping stirring after uniform stirring, continuously adding 380 parts of early-strength polycarboxylic acid water reducing agent, 20 parts of state regulator and 0.8 part of polyether modified organosilicon defoaming agent into the stirring kettle, continuously stirring, finally adding 0.2 part of alpha-alkenyl sodium sulfonate, and uniformly stirring to obtain the special concrete additive for the shield segments.
Example 3: the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 4000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 40% of an early-strength polycarboxylate water reducing agent with the side chain of 4000 molecular weight, 12% of an early-strength agent (namely 6% of calcium nitrate and 6% of calcium chloride), 2% of a state regulator, 0.08% of a defoaming agent (namely polyether modified organosilicon defoaming agent DT-650 produced by Nanhai field chemical Co., Ltd., Fushan City), 0.05% of an air entraining agent (namely triterpenoid saponin), and the balance of water, wherein the early-strength agent is a combination of 6% of calcium nitrate and 6% of calcium chloride; the sum of the mass percentages of the components is 100 percent. The preparation method of the concrete additive special for the shield segments comprises the following process steps of adding 60 parts of calcium nitrate and 60 parts of calcium chloride into a 2L stirring kettle according to a determined proportion, adding 458.7 parts of water, stopping stirring after stirring uniformly, continuously adding 400 parts of early-strength polycarboxylic acid water reducing agent, 20 parts of state regulator and 0.8 part of polyether modified organosilicon defoaming agent into the stirring kettle, continuously stirring, finally adding 0.5 part of triterpenoid saponin, and uniformly stirring to obtain the concrete additive special for the shield segments.
Example 4: the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 5000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 36 percent of early-strength polycarboxylate water reducing agent with the side chain of 5000 molecular weight, 6 percent of early-strength agent namely triisopropanolamine, 0.5 percent of state regulator, 0.1 percent of defoaming agent namely acetylene glycol defoaming agent, 0.05 percent of air entraining agent namely triterpenoid saponin, and the balance of water, wherein the sum of the mass percent of the components is 100 percent; the acetylene glycol defoaming agent can be surfynol df-110c acetylene glycol defoaming agent. The preparation method of the concrete additive special for the shield segments comprises the following process steps of adding 60 parts of triisopropanolamine into a 2L stirring kettle according to a determined proportion, adding 426.5 parts of water, stopping stirring after stirring uniformly, continuously adding 360 parts of early-strength polycarboxylic acid water reducing agent, 5 parts of state regulator and 1 part of acetylene glycol defoaming agent into the stirring kettle, continuously stirring, finally adding 0.5 part of triterpenoid saponin, and uniformly stirring to obtain the concrete additive special for the shield segments.
Example 5: the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 5000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 36 percent of early-strength polycarboxylate water reducing agent with the side chain of 5000 molecular weight, 12 percent of early-strength agent namely calcium nitrate, 1 percent of state regulator, 0.08 percent of defoaming agent namely polyether modified organosilicon defoaming agent (which can be DT-650 polyether modified organosilicon defoaming agent produced by Nanhai field chemical Co., Ltd. in Fushan city), 0.03 percent of air entraining agent namely alpha-alkenyl sodium sulfonate (AOS), and the balance of water, wherein the sum of the mass percent of the components is 100 percent. The preparation method of the special concrete additive for the shield segments comprises the following process steps of adding 120 parts of calcium nitrate and 508.9 parts of water into a 2L stirring kettle according to a determined proportion, stopping stirring after uniform stirring, continuously adding 360 parts of early-strength polycarboxylic acid water reducing agent, 10 parts of state regulator and 0.8 part of polyether modified organosilicon defoaming agent into the stirring kettle, continuously stirring, finally adding 0.3 part of alpha-alkenyl sodium sulfonate, and uniformly stirring to obtain the special concrete additive for the shield segments.
Example 6: the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 5000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 36 percent of early strength polycarboxylate water reducing agent with the side chain of 5000 molecular weight, 8 percent of early strength agent (namely 4 percent of sodium sulfate and 4 percent of lithium sulfate), 1 percent of state regulator, 0.12 percent of defoaming agent (acetylenic diol defoaming agent) (can be DT-650 polyether modified organosilicon defoaming agent produced by south China sea field chemical Co., Ltd., Fushan City), 0.02 percent of air entraining agent (namely fatty alcohol polyoxyethylene ether sodium sulfate (AES)), and the balance of water, wherein the early strength agent is the combination of 4 percent of sodium sulfate and 4 percent of lithium sulfate; the acetylene glycol defoaming agent can be surfynol df-110c acetylene glycol defoaming agent; the sum of the mass percentages of the components is 100 percent. The preparation method of the special concrete additive for the shield segment comprises the following process steps of adding 40 parts of sodium sulfate and 40 parts of lithium sulfate into a 2L stirring kettle according to a determined proportion, adding 548.6 parts of water, stopping stirring after stirring uniformly, continuously adding 360 parts of early-strength polycarboxylate water reducer, 10 parts of state regulator and 1.2 parts of acetylene glycol defoamer into the stirring kettle, continuously stirring, finally adding 0.2 part of fatty alcohol polyoxyethylene ether sodium sulfate, and uniformly stirring to obtain the special concrete additive for the shield segment.
Example 7: the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate superplasticizer with the side chain of 6000 molecular weight, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 33 percent of early-strength polycarboxylate water reducing agent with the side chain of 6000 molecular weight, 0 percent of early strength agent, 1.5 percent of state regulator, 0.1 percent of defoaming agent, namely acetylene glycol defoaming agent, 0.05 percent of air entraining agent, namely triterpenoid saponin, and the balance of water; the acetylene glycol defoaming agent can be surfynol df-110c acetylene glycol defoaming agent; the sum of the mass percentages of the components is 100 percent. The preparation method of the special concrete additive for the shield segments comprises the following process steps of adding 653.5 parts of water into a 2L stirring kettle according to a determined proportion, continuously adding 330 parts of early-strength polycarboxylic acid water reducing agent, 15 parts of state regulator and 1 part of acetylene glycol defoaming agent into the stirring kettle, continuously stirring, finally adding 0.5 part of triterpenoid saponin, and uniformly stirring to obtain the special concrete additive for the shield segments.
Example 8: the special concrete additive for the shield segment is prepared by compounding an early strength polycarboxylate water reducing agent with the side chain of 6000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and comprises the following components in percentage by mass: 35 percent of an early-strength polycarboxylate water reducing agent with the side chain of 6000 molecular weight, 4 percent of calcium nitrate as an early-strength agent, 1 percent of a state regulator, 0.1 percent of a defoaming agent, namely a polyether modified organosilicon defoaming agent (can be DT-650 polyether modified organosilicon defoaming agent produced by south China sea field chemical Co., Ltd., Fushan City), 0.05 percent of an air entraining agent, namely triterpenoid saponin, and the balance of water, wherein the sum of the mass percent of the components is 100 percent. The preparation method of the concrete additive special for the shield segments comprises the following process steps of adding 40 parts of calcium nitrate and 598.5 parts of water into a 2L stirring kettle according to a determined proportion, stopping stirring after uniform stirring, continuously adding 350 parts of early-strength polycarboxylic acid water reducing agent, 10 parts of state regulator and 1 part of polyether modified organosilicon defoaming agent into the stirring kettle, continuously stirring, finally adding 0.5 part of triterpenoid saponin, and uniformly stirring to obtain the concrete additive special for the shield segments.
The mixing amount of the invention is 0.5-1.5% (weight percentage) of the cementing material, and can adopt 1%.
The following are the experimental part of the invention: testing of concrete Properties
Raw material
Glue material: the cement brand is conch P.O42.5, the fly ash brand is Guihu F-II;
sand: machine-made sand, fineness modulus is 3.0, material: limestone;
stone: artificial crushing, the particle size is 5-25mm, and the material is as follows: limestone.
Table 1 shows the raw material mixing ratio. Table 2 shows the concrete performance test results.
TABLE 1 compounding ratio
| Material | Cement | Fly ash | Sand | Stone | Water (W) | Water reducing agent |
| 1m3 | 390kg | 43kg | 638kg | 1186kg | 138kg | 1.0％ |
TABLE 2 concrete Performance test results
Evaluating the appearance bubbles of the duct pieces: and analyzing the quantity of bubbles and the average particle size of the bubbles on the surface of the duct piece with the same area by using imagej image processing software, specifically reflecting the condition of the bubbles on the surface of the duct piece by digitalization, wherein the analysis result data are shown in a table 3.
TABLE 3 analysis result data (surface bubble condition of segment)
| Sample numbering | Number of bubbles | Average diameter of bubbles/mm |
| Commercial sample | 245 | 2.513 |
| Example 1 | 230 | 3.647 |
| Example 2 | 203 | 1.858 |
| Example 3 | 87 | 0.937 |
| Example 4 | 101 | 1.025 |
| Example 5 | 187 | 2.047 |
| Example 6 | 165 | 1.928 |
| Example 7 | 93 | 0.786 |
| Example 8 | 126 | 0.968 |
The model of the commercial sample in table 2 and table 3 is ViscoCrete 20 HE.
And (4) conclusion: according to the detection data, the requirements of the 8h steam-curing strength of the shield segment above 20Mpa can be completely met by using the early-strength polycarboxylate water reducing agent and the (inorganic salts and organic matters) early-strength agent, the reasonable collocation (type and dosage) of the defoaming agent and the air entraining agent and the use of the state regulator can obviously improve the appearance problem of the shield segment by improving the concrete state, and the rationality of the collocation is directly related to the whole bubble quantity and the bubble size problem of the shield segment. The use of the Imagj image processing software is more intuitive and scientific for analyzing the apparent bubbles, and provides objective basis for problem analysis.
In conclusion, the special concrete additive for the shield segment prepared by the embodiments of the invention can meet the requirement that the steam curing strength of the shield segment is more than 20MPa for 8 hours, and reduce bubbles and color difference on the appearance surface of the shield segment. The preparation process is simple, the production cost is low, compared with the prior art, the production cost of the invention is reduced by more than 10%, and the invention is suitable for industrial production.
Claims (10)
1. The special concrete additive for the shield segment is characterized by being prepared by compounding an early-strength polycarboxylate water reducer, an early-strength agent, a state regulator, a defoaming agent, an air entraining agent and water, wherein the mass percent of each component is as follows: 25-45% of an early-strength polycarboxylic acid water reducing agent, 0-12% of an early-strength agent, 0.5-3% of a state regulator, 0.05-0.2% of a defoaming agent, 0.01-0.1% of an air entraining agent and the balance of water, wherein the sum of the mass percentages of the components is 100%;
the early-strength polycarboxylate superplasticizer is an early-strength polycarboxylate superplasticizer with the side chain molecular weight of 4000-6000;
the state regulator is prepared from the following raw materials in parts by weight: 18.0 parts of acrylamide monomer, 1.5 parts of acrylic monomer, 1 part of vinyl acetate, 3.0 parts of polyether monomer, 3.0 parts of methyl allyl polyoxyethylene ether, wherein the weight average molecular weight of the methyl allyl polyoxyethylene ether is 1000, 0.04 part of initiator, 8.2 parts of alkali liquor, namely NaOH aqueous solution with the mass percentage concentration of 30%, and 1400 parts of deionized water; the initiator is a redox system, the oxidant is 0.02 part of ammonium persulfate, and the reducing agent is 0.02 part of sodium bisulfite; the preparation method of the state regulator comprises the following process steps: dispersing hydrophobic monomers in 140 parts of deionized water by using an ultrasonic disperser to obtain dispersion liquid, pouring the dispersion liquid into a three-neck flask, adding acrylamide monomers, acrylic monomers and polyether monomers into the three-neck flask, stirring, heating to 45 ℃, adding ammonium persulfate and sodium bisulfite into the three-neck flask, and carrying out heat preservation reaction for 4.5 hours to obtain an intermediate product; adding the rest deionized water into the intermediate product to dissolve and dilute the intermediate product, and then adding alkali liquor to neutralize to obtain a final product, namely the state regulator;
the early strength agent is one or a combination of more of inorganic salts, diethanolamine, triethanolamine, triisopropanolamine, calcium nitrate, calcium chloride, lithium sulfate and sodium sulfate in organic matters;
the preparation method of the concrete additive special for the shield segments comprises the following process steps of sequentially adding the early strength agent, water and the defoaming agent into a stirring kettle according to a determined proportion, uniformly stirring, adding the early strength polycarboxylic acid water reducing agent, the state regulator and the defoaming agent, continuously stirring, and finally adding the air entraining agent and uniformly stirring to obtain the concrete additive special for the shield segments.
2. The special concrete additive for shield segments as claimed in claim 1, wherein the early-strength polycarboxylate superplasticizer is one or a mixture of several of comb-structured polymers obtained by free radical polymerization of polyether macromonomer having side chain molecular weights of 4000, 5000, and 6000 and acrylic acid.
3. The special concrete additive for shield segments according to claim 1, wherein the defoamer is one or a combination of more of a dimethyl silicone defoamer, a polyether modified silicone defoamer and an acetylene glycol defoamer; the air entraining agent is one or a combination of more of triterpenoid saponin, sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether sodium sulfate and alpha-alkenyl sodium sulfonate.
4. The special concrete additive for the shield segments according to claim 1, which is prepared by compounding an early-strength polycarboxylic acid water reducer with a side chain of 4000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, wherein the mass percentages of the components are as follows: 38 percent of early-strength polycarboxylate water reducing agent with the side chain of 4000 molecular weight, 9 percent of early strength agent, 2 percent of state regulator, 0.08 percent of defoaming agent, namely polyether modified organosilicon defoaming agent, 0.02 percent of air entraining agent, namely alpha-alkenyl sodium sulfonate, and the balance of water, wherein the early strength agent is the combination of 6 percent of calcium nitrate and 3 percent of triethanolamine; the sum of the mass percentages of the components is 100 percent; the preparation method of the special concrete additive for the shield segments comprises the following process steps of adding 60 parts of calcium nitrate and 30 parts of triethanolamine into a 2L stirring kettle according to a determined proportion, adding 509 parts of water, stopping stirring after uniform stirring, continuously adding 380 parts of early-strength polycarboxylic acid water reducing agent, 20 parts of state regulator and 0.8 part of polyether modified organosilicon defoaming agent into the stirring kettle, continuously stirring, finally adding 0.2 part of alpha-alkenyl sodium sulfonate, and uniformly stirring to obtain the special concrete additive for the shield segments.
5. The special concrete additive for the shield segments according to claim 1, which is prepared by compounding an early-strength polycarboxylic acid water reducer with a side chain of 4000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, wherein the mass percentages of the components are as follows: 40% of an early-strength polycarboxylate water reducing agent with the side chain of 4000 molecular weight, 12% of an early-strength agent, 2% of a state regulator, 0.08% of a defoaming agent, namely a polyether modified organosilicon defoaming agent, 0.05% of an air entraining agent, namely triterpene saponin, and the balance of water, wherein the early-strength agent is a combination of 6% of calcium nitrate and 6% of calcium chloride; the sum of the mass percentages of the components is 100 percent; the preparation method of the concrete additive special for the shield segments comprises the following process steps of adding 60 parts of calcium nitrate and 60 parts of calcium chloride into a 2L stirring kettle according to a determined proportion, adding 458.7 parts of water, stopping stirring after stirring uniformly, continuously adding 400 parts of early-strength polycarboxylic acid water reducing agent, 20 parts of state regulator and 0.8 part of polyether modified organosilicon defoaming agent into the stirring kettle, continuously stirring, finally adding 0.5 part of triterpenoid saponin, and uniformly stirring to obtain the concrete additive special for the shield segments.
6. The special concrete additive for the shield segments according to claim 1, which is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 5000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, wherein the mass percentages of the components are as follows: 36 percent of early-strength polycarboxylate water reducing agent with the side chain of 5000 molecular weight, 12 percent of early-strength agent namely calcium nitrate, 1 percent of state regulator, 0.08 percent of defoaming agent namely polyether modified organosilicon defoaming agent, 0.03 percent of air entraining agent namely alpha-alkenyl sodium sulfonate, and the balance of water, wherein the sum of the mass percent of the components is 100 percent; the preparation method of the special concrete additive for the shield segments comprises the following process steps of adding 120 parts of calcium nitrate and 508.9 parts of water into a 2L stirring kettle according to a determined proportion, stopping stirring after uniform stirring, continuously adding 360 parts of early-strength polycarboxylic acid water reducing agent, 10 parts of state regulator and 0.8 part of polyether modified organosilicon defoaming agent into the stirring kettle, continuously stirring, finally adding 0.3 part of alpha-alkenyl sodium sulfonate, and uniformly stirring to obtain the special concrete additive for the shield segments.
7. The special concrete additive for the shield segments according to claim 1, which is prepared by compounding an early-strength polycarboxylate water reducer with a side chain of 5000 molecular weight, an early strength agent, a state regulator, a defoaming agent, an air entraining agent and water, wherein the mass percentages of the components are as follows: 36 percent of early-strength polycarboxylate water reducing agent with the side chain of 5000 molecular weight, 8 percent of early strength agent, 1 percent of state regulator, 0.12 percent of defoaming agent which is acetylene glycol defoaming agent, 0.02 percent of air entraining agent which is sodium fatty alcohol-polyoxyethylene ether sulfate, and the balance of water, wherein the early strength agent is the combination of 4 percent of sodium sulfate and 4 percent of lithium sulfate; the sum of the mass percentages of the components is 100 percent;
the preparation method of the special concrete additive for the shield segment comprises the following process steps of adding 40 parts of sodium sulfate and 40 parts of lithium sulfate into a 2L stirring kettle according to a determined proportion, adding 548.6 parts of water, stopping stirring after stirring uniformly, continuously adding 360 parts of early-strength polycarboxylate water reducer, 10 parts of state regulator and 1.2 parts of acetylene glycol defoamer into the stirring kettle, continuously stirring, finally adding 0.2 part of fatty alcohol polyoxyethylene ether sodium sulfate, and uniformly stirring to obtain the special concrete additive for the shield segment.
8. The special concrete additive for shield segments according to claim 1, which is prepared by compounding an early-strength polycarboxylate superplasticizer with a side chain of 6000 molecular weight, a state regulator, a defoaming agent, an air entraining agent and water, wherein the mass percentages of the components are as follows: 33 percent of early-strength polycarboxylate water reducing agent with the side chain of 6000 molecular weight, 0 percent of early strength agent, 1.5 percent of state regulator, 0.1 percent of defoaming agent, namely acetylene glycol defoaming agent, 0.05 percent of air entraining agent, namely triterpenoid saponin, and the balance of water; the sum of the mass percentages of the components is 100 percent;
the preparation method of the special concrete additive for the shield segments comprises the following process steps of adding 653.5 parts of water into a 2L stirring kettle according to a determined proportion, continuously adding 330 parts of early-strength polycarboxylic acid water reducing agent, 15 parts of state regulator and 1 part of acetylene glycol defoaming agent into the stirring kettle, continuously stirring, finally adding 0.5 part of triterpenoid saponin, and uniformly stirring to obtain the special concrete additive for the shield segments.
9. The preparation method of the special concrete additive for the shield segment as claimed in claim 1, wherein the special concrete additive for the shield segment is prepared by compounding an early-strength polycarboxylate superplasticizer, an early-strength agent, a state regulator, a defoaming agent, an air entraining agent and water, and the mass percentages of the components are as follows: 25-45% of an early-strength polycarboxylic acid water reducing agent, 0-12% of an early-strength agent, 0.5-3% of a state regulator, 0.05-0.2% of a defoaming agent, 0.01-0.1% of an air entraining agent and the balance of water, wherein the sum of the mass percentages of the components is 100%; the early-strength polycarboxylate superplasticizer is an early-strength polycarboxylate superplasticizer with the side chain molecular weight of 4000-6000; the state regulator is prepared from the following raw materials in parts by weight: 18.0 parts of acrylamide monomer, 1.5 parts of acrylic monomer, 1 part of vinyl acetate, 3.0 parts of polyether monomer, 3.0 parts of methyl allyl polyoxyethylene ether, wherein the weight average molecular weight of the methyl allyl polyoxyethylene ether is 1000, 0.04 part of initiator, 8.2 parts of alkali liquor, namely NaOH aqueous solution with the mass percentage concentration of 30%, and 1400 parts of deionized water; the initiator is a redox system, the oxidant is 0.02 part of ammonium persulfate, and the reducing agent is 0.02 part of sodium bisulfite; the preparation method of the state regulator comprises the following process steps: dispersing hydrophobic monomers in 140 parts of deionized water by using an ultrasonic disperser to obtain dispersion liquid, pouring the dispersion liquid into a three-neck flask, adding acrylamide monomers, acrylic monomers and polyether monomers into the three-neck flask, stirring, heating to 45 ℃, adding ammonium persulfate and sodium bisulfite into the three-neck flask, and carrying out heat preservation reaction for 4.5 hours to obtain an intermediate product; adding the rest deionized water into the intermediate product to dissolve and dilute the intermediate product, and then adding alkali liquor to neutralize to obtain a final product, namely the state regulator; the early strength agent is one or a combination of more of inorganic salts, diethanolamine, triethanolamine, triisopropanolamine, calcium nitrate, calcium chloride, lithium sulfate and sodium sulfate in organic matters;
the preparation method of the concrete additive special for the shield segments comprises the following process steps of sequentially adding the early strength agent, water and the defoaming agent into a stirring kettle according to a determined proportion, uniformly stirring, adding the early strength polycarboxylic acid water reducing agent, the state regulator and the defoaming agent, continuously stirring, and finally adding the air entraining agent and uniformly stirring to obtain the concrete additive special for the shield segments.
10. The method for preparing the concrete additive special for the shield segment according to claim 9, wherein the defoaming agent is one or a combination of more of a dimethyl silicone defoaming agent, a polyether modified silicone defoaming agent and an acetylene glycol defoaming agent; the air entraining agent is one or a combination of more of triterpenoid saponin, sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether sodium sulfate and alpha-alkenyl sodium sulfonate.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111362612A (en) * | 2018-12-26 | 2020-07-03 | 江苏苏博特新材料股份有限公司 | Polycarboxylate superplasticizer special for rock-fill dam C15 self-compacting concrete |
| CN114395073A (en) * | 2022-01-06 | 2022-04-26 | 山西佳维新材料股份有限公司 | Complex excitation polymer and preparation method and application thereof |
-
2020
- 2020-09-17 CN CN202010978536.6A patent/CN112047663A/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111362612A (en) * | 2018-12-26 | 2020-07-03 | 江苏苏博特新材料股份有限公司 | Polycarboxylate superplasticizer special for rock-fill dam C15 self-compacting concrete |
| CN111362612B (en) * | 2018-12-26 | 2022-03-18 | 江苏苏博特新材料股份有限公司 | Polycarboxylate superplasticizer special for rock-fill dam C15 self-compacting concrete |
| CN114395073A (en) * | 2022-01-06 | 2022-04-26 | 山西佳维新材料股份有限公司 | Complex excitation polymer and preparation method and application thereof |
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