CN116903283A - Cementing material reinforcing agent with high fly ash content and preparation method thereof, concrete and preparation method thereof - Google Patents

Cementing material reinforcing agent with high fly ash content and preparation method thereof, concrete and preparation method thereof Download PDF

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Publication number
CN116903283A
CN116903283A CN202310509263.4A CN202310509263A CN116903283A CN 116903283 A CN116903283 A CN 116903283A CN 202310509263 A CN202310509263 A CN 202310509263A CN 116903283 A CN116903283 A CN 116903283A
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fly ash
cementing material
concrete
reinforcing agent
cement
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张润潇
俞英田
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Canda Shenzhen New Material Technology Co ltd
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Canda Shenzhen New Material Technology Co ltd
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Priority to CN202310509263.4A priority Critical patent/CN116903283A/en
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    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B18/00Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
    • C04B18/04Waste materials; Refuse
    • C04B18/30Mixed waste; Waste of undefined composition
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/02Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
    • C04B28/04Portland cements
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474Uses not provided for elsewhere in C04B2111/00
    • C04B2111/00724Uses not provided for elsewhere in C04B2111/00 in mining operations, e.g. for backfilling; in making tunnels or galleries
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2201/00Mortars, concrete or artificial stone characterised by specific physical values
    • C04B2201/50Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Civil Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Processing Of Solid Wastes (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

The invention discloses a cementing material reinforcing agent with high fly ash content, a preparation method thereof, concrete and a preparation method thereof, and belongs to the field of cement chemical industry. The cementing material reinforcing agent with high fly ash mixing amount comprises the following components: the cement material comprises waste salt and carbide slag, wherein the waste salt at least contains 60% of sodium sulfate, the carbide slag at least contains 80% of calcium hydroxide, the cementing material reinforcing agent with high fly ash content is used for improving the 28-day strength of the cementing material for mine backfilling, and the cementing material contains at least 80% of fly ash. The cementing material reinforcing agent with high fly ash content provided by the invention has low cost and excellent strength improving effect on cementing materials in concrete.

Description

Cementing material reinforcing agent with high fly ash content and preparation method thereof, concrete and preparation method thereof
Technical Field
The invention relates to the field of cement chemical industry, in particular to a cementing material reinforcing agent with high fly ash content, a preparation method thereof, concrete and a preparation method thereof.
Background
In the present stage, the energy demand of China is continuously increased, the mining intensity is gradually increased, the larger the space below the ground is, the larger the damage to the geology is, and collapse is possibly caused by carelessness, so that backfilling is carried out after the mine is mined, and the mine backfilling is one of key links of mining enterprises for realizing mining area reclamation and ecological environmental protection, and has important social and environmental significance.
The backfill volume of the abandoned mine in China is huge, the cementing material in the used concrete is mainly made of materials containing a large amount of Portland cement, and the cementing material reinforcing agent with high fly ash mixing amount is mainly made of an external reinforcing agent of alcohols or polycarboxylic acids, so that the cost of the concrete and the reinforcing agent thereof meeting the backfill strength requirement is high, and the backfill willingness of mining enterprises is limited.
Disclosure of Invention
In view of the defects in the prior art, the invention provides a cementing material reinforcing agent with high fly ash content, a preparation method thereof, concrete and a preparation method thereof, and aims to solve the problem that the cost of the concrete and the reinforcing agent thereof meeting the requirement of backfill strength is high at present.
In order to achieve the above purpose, the present invention provides a cement reinforcing agent with high fly ash content, comprising: the cement material comprises waste salt and carbide slag, wherein the waste salt at least contains 60% of sodium sulfate, the carbide slag at least contains 80% of calcium hydroxide, the cementing material reinforcing agent with high fly ash content is used for improving the 28-day strength of the cementing material for mine backfilling, and the cementing material contains at least 80% of fly ash.
Optionally, the mass ratio of the sodium sulfate to the calcium hydroxide is (2:1) - (1:2).
The invention also provides concrete for mine backfilling, which comprises a cementing material treated by the cementing material reinforcing agent with high fly ash content, wherein the cementing material comprises cement, fly ash and pozzolanic mineral admixture.
Optionally, the mass ratio of the cementing material to the cementing material reinforcing agent with high fly ash mixing amount is 20 (0.5-2.1).
Optionally, the composition comprises the following components in parts by weight: 1 to 2 parts of cement, 16 to 19 parts of fly ash, 0.84 to 2.5 parts of waste salt and 0.75 to 1.25 parts of carbide slag,
the waste salt at least contains 60% of sodium sulfate, and the carbide slag at least contains 80% of calcium hydroxide.
In order to achieve the above purpose, the invention also provides a preparation method of the cementing material reinforcing agent with high fly ash mixing amount, which comprises the following steps: drying the waste salt and carbide slag until the water content is less than or equal to 5% to obtain a mixture; and (3) mixing and grinding the mixture in proportion until the particle size of the mixture is more than 200 meshes, thereby obtaining the cementing material reinforcing agent with high fly ash mixing amount.
Optionally, the drying temperature is 60-80 ℃.
In order to achieve the above object, the present invention also provides a method for preparing concrete, comprising the steps of: adding the first raw material or the second raw material into a stirrer for first dry mixing to obtain a first dry material; adding aggregate into the first dry material for secondary dry mixing to obtain a second dry material; adding the first liquid or the second liquid into the second dry material, and stirring to obtain the concrete; the first raw materials comprise cement, fly ash, carbide slag and waste salt, the second raw materials comprise cement, fly ash and carbide slag, the first liquid comprises water and a chemical additive, the second liquid comprises water, a chemical additive and strong brine-like waste salt, when the first dry-mixed raw materials are first raw materials, the first liquid is added through stirring, and when the first dry-mixed raw materials are second raw materials, the second liquid is added through stirring.
Optionally, the time of the first dry mixing is 1-3 minutes, the time of the second dry mixing is 0.5-2 minutes, and the time of adding the liquid into the second dry material and stirring is 1-5 minutes.
The invention has the beneficial effects that: the cementing material reinforcing agent with high fly ash content only comprises two raw materials, namely waste salt and carbide slag, wherein the waste salt is used for providing sodium sulfate, and a part of sodium sulfate can react with silicate cement in the cementing material to generate ettringite crystals with expansibility, so that pores in the concrete are filled, and the cement strength is rapidly improved; the calcium carbide slag is used for providing calcium hydroxide to form a pH alkaline environment with the pH value of more than 13 in backfilled concrete pore water, and the caustic metal ions provided by unreacted sodium sulfate are combined to achieve the effect similar to that of sodium hydroxide, so that activated silica, calcium silicate and calcium aluminosilicate contained in the fly ash in the cementing material are excited and combined with calcium ions provided by the calcium hydroxide to generate a certain amount of compact hydration products, thereby improving the internal structure of the hardened slurry and the overall performance of the hardened slurry.
Therefore, the proportion of sodium sulfate and calcium hydroxide in the cementing material reinforcing agent with high fly ash mixing amount can be adjusted, so that the amount of the fly ash in the cementing material can be increased, the cement amount in the cementing material is greatly reduced, the volume stability of the cementing material is increased, the strength and the durability are improved, and the 28-day strength improvement effect on concrete is excellent. The strength of the concrete can be greatly improved under the condition of the same cement dosage, and the cement dosage can be greatly reduced under the condition of the same concrete strength requirement.
The cementing material reinforcing agent with high fly ash content provided by the invention adopts full solid waste raw materials, has extremely low cost and simple process, and has extremely high industrial popularization value.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below, and it should be understood that the following embodiments are only for explaining the present invention and are not limited thereto.
Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning in the art to which the claimed subject matter belongs.
In the present stage, the energy demand of China is continuously increased, the mining intensity is gradually increased, the larger the space below the ground is, the larger the damage to the geology is, and collapse is possibly caused by carelessness, so that backfilling is carried out after the mine is mined, and the mine backfilling is one of key links of mining enterprises for realizing mining area reclamation and ecological environmental protection, and has important social and environmental significance.
The backfill volume of the abandoned mine in China is huge, the cementing material is mainly made of materials containing a large amount of Portland cement, the reinforcing agent is mainly made of an additive reinforcing agent of alcohols or polycarboxylic acids, so that the cost of the concrete and the reinforcing agent thereof meeting the requirement of backfill strength is high, and the backfill willingness of mining enterprises is limited.
In order to solve the problems, the invention provides a cementing material reinforcing agent with high fly ash mixing amount, which comprises the following components: the cement material comprises waste salt and carbide slag, wherein the waste salt at least contains 60% of sodium sulfate, the carbide slag at least contains 80% of calcium hydroxide, the cementing material reinforcing agent with high fly ash content is used for improving the 28-day strength of the cementing material for mine backfilling, and the cementing material contains at least 80% of fly ash. Sodium sulfate reacts with concrete to generate ettringite crystals with expansibility, so that pores in the concrete are filled, and the cement strength is improved; the carbide slag is used for providing calcium hydroxide, and reacts with a certain amount of active silicon oxide and aluminum oxide in the concrete slurry to generate a certain amount of compact hydration product, so that the internal structure of the hardened slurry is improved, and the overall performance of the hardened body is improved. In one embodiment, both the waste salt and the carbide slag are collected in solid form with some moisture. In another embodiment, the carbide slag is collected as a solid with some moisture and the waste salt is collected as a strong brine.
Further, the mass ratio of sodium sulfate to calcium hydroxide is (2:1) - (1:2). The sodium sulfate and a portion of the calcium hydroxide in the high fly ash loading cement enhancer may be in accordance with about 2: the mass ratio of 1 is reacted to generate sodium hydroxide, the sodium hydroxide can excite silicate and aluminosilicate contained in the fly ash in the cementing material to generate strength more quickly, in addition, the calcium hydroxide is slightly excessively added in the proportion of the reinforcing agent, and the independent existence of the calcium hydroxide has a certain excitation effect on silicate/aluminosilicate in the fly ash of the cementing material and can promote early hydration reaction of cement. The sodium sulfate is excessive in dosage and exceeds the specified range, so that unreacted sodium sulfate is easy to separate out in the later period. The proportion of sodium sulfate and calcium hydroxide in the cementing material reinforcing agent with high fly ash mixing amount can be adjusted, so that the amount of fly ash in the cementing material can be increased, the amount of cement in the cementing material can be greatly reduced, the volume stability can be increased, and the strength and the durability can be improved. Preferably, the mass ratio of the sodium sulfate to the calcium hydroxide is 0.5 (0.2-1). Preferably, the mass ratio of sodium sulfate to calcium hydroxide is 0.5:0.2 or 0.5:1.
In order to solve the problems, the invention also provides concrete for mine backfill, which comprises a cementing material treated by the cementing material reinforcing agent with high fly ash mixing amount, wherein the cementing material comprises cement, fly ash and pozzolanic mineral admixture. The cementing material can be changed into a firm stone-shaped body from slurry and can be used for cementing other materials to prepare a compound solid substance with certain mechanical strength. The cementing material is high in fly ash consumption, the consumption is more than 80%, the fly ash hydration heat is low, the source is wide, the price is low, the cementing material has three effects of volcanic ash effect, secondary reaction effect, filling effect and the like as concrete components, the fly ash is used for replacing a certain amount of cement, the fly ash is directly doped into the concrete without modification to prepare the fly ash concrete, the fluidity of the freshly mixed concrete can be increased, bleeding segregation is improved, the later strength of the concrete is increased, the durability is improved, but the activity of the fly ash is lower, the strength is slowly increased, the early strength is lower, and when the fly ash is used for replacing the cement cementing material, the activity of the fly ash is excited by adding the cementing material reinforcing agent with the high fly ash doping amount by more than 60%, so that the defect of the early strength is overcome.
Further, the mass ratio of the cementing material to the cementing material reinforcing agent with high fly ash mixing amount is 20 (0.5-2.1). The solubility of the calcium hydroxide is not high, the dissolution rate and the reaction degree are considered, the use effect cannot be improved due to the excessive use of the reinforcing agent, and unreacted sodium sulfate exists in the system due to the excessive use of the reinforcing agent, so that the sodium sulfate is easy to separate out in a later period and has a certain negative effect on the environment.
Further, the method comprises the following steps in parts by weight: 1 to 2 parts of cement, 16 to 19 parts of fly ash, 0.84 to 2.5 parts of waste salt and 0.75 to 1.25 parts of carbide slag, wherein the waste salt at least contains 60 percent of sodium sulfate, and the carbide slag at least contains 80 percent of calcium hydroxide. The cementing material part in the concrete is limited according to the proportion, and the concrete with obviously enhanced 28-day strength can be obtained after the cementing material part is matched with aggregate.
In order to solve the problems, the invention also provides a preparation method of the cementing material reinforcing agent with high fly ash mixing amount, which comprises the following steps: drying the waste salt and carbide slag until the water content is less than or equal to 5% to obtain a mixture; and (3) mixing and grinding the mixture in proportion until the particle size of the mixture is more than 200 meshes, thereby obtaining the cementing material reinforcing agent with high fly ash mixing amount. In one embodiment, if both the waste salt and the carbide slag are in solid form with a certain moisture content, the two materials are dried first until the moisture content is less than or equal to 5%; and throwing the dried two materials into a ball mill according to the preset mass ratio of sodium sulfate to calcium hydroxide, grinding the materials into a size of more than 200 meshes, and obtaining the cementing material reinforcing agent with high fly ash mixing amount. The ball mill may be replaced with other types of milling machines.
Further, the drying temperature is 60-80 ℃. Drying in the temperature range can avoid the reaction of industrial waste salt and organic matters in carbide slag, avoid hardening of the waste salt, cause poor heat transfer effect, influence the treatment effect of equipment and dry mixing treatment of cementing materials and aggregates.
In order to solve the problems, the invention also provides a preparation method of the concrete, which comprises the following steps: adding the first raw material or the second raw material into a stirrer for first dry mixing to obtain a first dry material; adding aggregate into the first dry material for secondary dry mixing to obtain a second dry material; adding the first liquid or the second liquid into the second dry material, and stirring to obtain the concrete; the first raw materials comprise cement, fly ash, carbide slag and waste salt, the second raw materials comprise cement, fly ash and carbide slag, the first liquid comprises water and a chemical additive, the second liquid comprises water, a chemical additive and strong brine-like waste salt, when the first dry-mixed raw materials are first raw materials, the first liquid is added through stirring, and when the first dry-mixed raw materials are second raw materials, the second liquid is added through stirring.
The water addition and subtraction amount can increase or decrease the fluidity of the concrete, but excessive water addition easily causes the concrete to crack and also can reduce the strength of the concrete, so that the chemical additive is added for assisting in adjusting the fluidity of the wet concrete, and can be a water reducing agent, a retarder or an air entraining agent and the like. In one embodiment, the chemical additive is a water reducing agent, which reduces the amount of mixing water while maintaining almost the degree of concrete collapse. Most of the water reducer belongs to negative ion surfactants, and after the water reducer is added into the concrete mixture, the water reducer plays a role in dispersing cement particles, so that the operability can be improved, the unit water consumption is reduced, and the fluidity of the concrete mixture is improved. The water reducer can be selected from lignosulfonate water reducer, naphthalene-based high-efficiency water reducer, melamine-based high-efficiency water reducer, sulfamate-based high-efficiency water reducer, fatty acid-based high-efficiency water reducer or polycarboxylic acid-based high-efficiency water reducer.
Further, the time of the first dry mixing is 1-3 minutes, the time of the second dry mixing is 0.5-2 minutes, and the time of adding the liquid into the second dry material and stirring is 1-5 minutes. If the dry mixing time is too short, the particles cannot be fully and uniformly mixed, so that the concrete has insufficient strength and is easy to crack; if the stirring time is too long, the water is evaporated too much, so that the fluidity of the concrete is affected, and the construction is affected.
Example 1:
1 part of cement, 19 parts of fly ash, 1.5 parts of waste salt containing sodium sulfate and 0.6 part of calcium hydroxide are added into a stirrer for 2 minutes of dry mixing, aggregate is added into the stirrer for continuous dry mixing for 0.5 minutes, and finally water and chemical additives are added into the stirrer for 3 minutes of stirring, so that the concrete is obtained.
Example 2:
adding 2 parts of cement, 18 parts of fly ash, 1.5 parts of waste salt containing sodium sulfate and 0.6 part of calcium carbide slag into a stirrer, carrying out dry mixing for 2 minutes, adding aggregate into the stirrer, continuously carrying out dry mixing for 1 minute, finally adding water and chemical additives into the stirrer, and stirring for 3 minutes to obtain the concrete.
Example 3:
adding 1 part of cement, 19 parts of fly ash, 0.5 part of waste salt containing sodium sulfate and 1 part of calcium carbide slag into a stirrer, carrying out dry mixing for 2 minutes, adding aggregate into the stirrer, continuously carrying out dry mixing for 0.5 minutes, finally adding water and chemical additives into the stirrer, and stirring for 4 minutes to obtain the concrete.
Example 4:
adding 2 parts of cement, 18 parts of fly ash, 0.5 part of waste salt containing sodium sulfate and 1 part of calcium carbide slag into a stirrer, carrying out dry mixing for 2 minutes, adding aggregate into the stirrer, continuously carrying out dry mixing for 1 minute, finally adding water and chemical additives into the stirrer, and stirring for 4 minutes to obtain the concrete.
Example 5:
adding 1 part of cement, 19 parts of fly ash and carbide slag containing 0.6 part of calcium hydroxide into a stirrer for 2 minutes and dry mixing, adding aggregate into the stirrer for continuous dry mixing for 1 minute, and finally adding water, chemical additives and strong brine-like waste salt containing 1.5 parts of sodium sulfate into the stirrer and stirring for 1 minute to obtain the concrete.
Example 6:
adding 1 part of cement, 19 parts of fly ash and carbide slag containing 0.6 part of calcium hydroxide into a stirrer for 2 minutes and dry mixing, adding aggregate into the stirrer for continuous dry mixing for 2 minutes, and finally adding water, chemical additives and strong brine-like waste salt containing 1 part of sodium sulfate into the stirrer and stirring for 5 minutes to obtain the concrete.
Example 7:
adding 2 parts of cement, 18 parts of fly ash and carbide slag containing 1 part of calcium hydroxide into a stirrer for 2 minutes and dry mixing, adding aggregate into the stirrer for continuous dry mixing for 1 minute, and finally adding water, chemical additives and strong brine-like waste salt containing 0.5 part of sodium sulfate into the stirrer and stirring for 3 minutes to obtain the concrete.
Example 8:
adding 2 parts of cement, 18 parts of fly ash and carbide slag containing 1 part of calcium hydroxide into a stirrer for 2 minutes and dry mixing, adding aggregate into the stirrer for continuous dry mixing for 2 minutes, and finally adding water, chemical additives and strong brine-like waste salt containing 1 part of sodium sulfate into the stirrer for 5 minutes and stirring to obtain the concrete.
Comparative example 1:
adding 1 part of cement and 19 parts of fly ash into a stirrer for 1 minute dry mixing, adding aggregate into the stirrer for continuous dry mixing for 0.5 minute, adding water and chemical additives into the stirrer, and stirring for 3 minutes to obtain the concrete.
Comparative example 2:
adding 2 parts of cement and 18 parts of fly ash into a stirrer for 1 minute dry mixing, adding aggregate into the stirrer for continuous dry mixing for 1 minute, adding water and chemical additives into the stirrer, and stirring for 3 minutes to obtain the concrete.
Comparative example 3:
adding 4 parts of cement and 16 parts of fly ash into a stirrer for 1 minute dry mixing, adding aggregate into the stirrer for continuous dry mixing for 1 minute, adding water and chemical additives into the stirrer, and stirring for 3 minutes to obtain the concrete.
Further, concrete strength performance tests were performed on examples 1 to 4 and comparative examples 1 to 3, the specific test method was performed according to national energy industry standard NB/T51070-2017, the 28-day strength was specifically tested, and the test results were calculated and evaluated according to building mortar basic performance experimental method standard JGJ/T70-2009.
The test results are summarized in table 1.
TABLE 1 concrete Strength Performance test of examples 1-4 and comparative examples 1-3
Through the above treatment effect experiment, compared with comparative example 1, the 28-day strength of the cementing material of 1 part of cement and 19 parts of fly ash of the invention can be intuitively seen to be improved by 2.4-2.9/MPa from 0/MPa, and compared with comparative example 2, the 28-day strength of the cementing material of 2 parts of cement and 18 parts of fly ash is improved by 3.1-4.3/MPa from 0.9/MPa in the example 2 and the example 4. Meanwhile, by comparing the data with comparative example 3, it can be found that the strength of 28 days can approach the strength effect achieved by adding 4 parts of cement after adding 1 part of cement to the high fly ash-doped cementing material reinforcing agent provided by the invention, and the strength effect achieved by adding 2 parts of cement to the high fly ash-doped cementing material reinforcing agent provided by the invention can be exceeded by 4 parts of cement.
The cementing material reinforcing agent with high fly ash content only comprises two raw materials, namely waste salt and carbide slag, wherein the waste salt is used for providing sodium sulfate, and a part of sodium sulfate can react with silicate cement in the cementing material to generate ettringite crystals with expansibility, so that pores in the concrete are filled, and the cement strength is rapidly improved; the calcium carbide slag is used for providing calcium hydroxide to form a pH alkaline environment with the pH value of more than 13 in backfilled concrete pore water, and the caustic metal ions provided by unreacted sodium sulfate are combined to achieve the effect similar to that of sodium hydroxide, so that activated silica, calcium silicate and calcium aluminosilicate contained in the fly ash in the cementing material are excited and combined with calcium ions provided by the calcium hydroxide to generate a certain amount of compact hydration products, thereby improving the internal structure of the hardened slurry and the overall performance of the hardened slurry.
Therefore, the proportion of sodium sulfate and calcium hydroxide in the cementing material reinforcing agent with high fly ash mixing amount can be adjusted, so that the amount of the fly ash in the cementing material can be increased, the cement amount in the cementing material is greatly reduced, the volume stability of the cementing material is increased, the strength and the durability are improved, and the 28-day strength improvement effect on concrete is excellent. The strength of the concrete can be greatly improved under the condition of the same cement dosage, and the cement dosage can be greatly reduced under the condition of the same concrete strength requirement.
The cementing material reinforcing agent with high fly ash content provided by the invention adopts full solid waste raw materials, has extremely low cost and simple process, and has extremely high industrial popularization value.
The foregoing is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention, but various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (9)

1. A high fly ash loading cementitious material enhancer of high fly ash loading, comprising: the cement material comprises waste salt and carbide slag, wherein the waste salt at least contains 60% of sodium sulfate, the carbide slag at least contains 80% of calcium hydroxide, the cementing material reinforcing agent with high fly ash content is used for improving the 28-day strength of the cementing material for mine backfilling, and the cementing material contains at least 80% of fly ash.
2. The high fly ash loading cementitious material enhancer of claim 1, wherein the mass ratio of sodium sulfate to calcium hydroxide is from (2:1) to (1:2).
3. A concrete for mine backfill comprising a cementitious material treated with a high fly ash loading cementitious material enhancer of claims 1-2, said cementitious material comprising cement, fly ash and a pozzolanic mineral admixture.
4. A concrete according to claim 3, wherein the mass ratio of the cementing material to the cementing material reinforcing agent with high fly ash content is 20 (0.5-2.5).
5. A concrete according to claim 3, comprising, in parts by weight: 1-2 parts of cement, 18-19 parts of fly ash, 0.84-2.5 parts of waste salt and 0.75-1.25 parts of carbide slag, wherein the waste salt at least contains 60% of sodium sulfate, and the carbide slag at least contains 80% of calcium hydroxide.
6. A method for preparing the high fly ash loading cementing material reinforcing agent as set forth in claim 1-2, comprising the steps of:
drying the waste salt and carbide slag until the water content is less than or equal to 5% to obtain a mixture;
and (3) mixing and grinding the mixture in proportion until the particle size of the mixture is more than 200 meshes, thereby obtaining the cementing material reinforcing agent with high fly ash mixing amount.
7. The method of preparing a high fly ash loading cementitious material enhancer of claim 6 wherein said drying temperature is from 60 to 80 ℃.
8. A method of preparing a concrete according to claims 3 to 5, comprising the steps of:
adding the first raw material or the second raw material into a stirrer for first dry mixing to obtain a first dry material;
adding aggregate into the first dry material for secondary dry mixing to obtain a second dry material;
adding the first liquid or the second liquid into the second dry material, and stirring to obtain the concrete;
the first raw material comprises cement, fly ash, carbide slag and waste salt, the second raw material comprises cement, fly ash and carbide slag,
the first liquid comprises water and chemical additives, the second liquid comprises water, chemical additives and brine-like waste salts,
when the first dry blend is the first raw material, the first liquid is added with stirring,
when the first dry blend is the second feedstock, the stirring adds the second liquid.
9. The method of preparing concrete according to claim 8, wherein the time of the "first dry mixing" is 1 to 3 minutes, the time of the "second dry mixing" is 0.5 to 2 minutes, and the time of adding the liquid to the second dry material is 1 to 5 minutes.
CN202310509263.4A 2023-05-08 2023-05-08 Cementing material reinforcing agent with high fly ash content and preparation method thereof, concrete and preparation method thereof Pending CN116903283A (en)

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Citations (2)

* Cited by examiner, † Cited by third party
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CN107602023A (en) * 2017-10-17 2018-01-19 南京建高新材料科技有限公司 A kind of high volume fly ash concrete and preparation method thereof
CN115490447A (en) * 2022-10-09 2022-12-20 碳达(深圳)新材料技术有限责任公司 Full-solid waste alkali-activated cementing material and preparation method thereof

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CN107602023A (en) * 2017-10-17 2018-01-19 南京建高新材料科技有限公司 A kind of high volume fly ash concrete and preparation method thereof
CN115490447A (en) * 2022-10-09 2022-12-20 碳达(深圳)新材料技术有限责任公司 Full-solid waste alkali-activated cementing material and preparation method thereof

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