CN113480214A - Recycled aggregate modifier for concrete and preparation method and use method thereof - Google Patents

Recycled aggregate modifier for concrete and preparation method and use method thereof Download PDF

Info

Publication number
CN113480214A
CN113480214A CN202110715045.7A CN202110715045A CN113480214A CN 113480214 A CN113480214 A CN 113480214A CN 202110715045 A CN202110715045 A CN 202110715045A CN 113480214 A CN113480214 A CN 113480214A
Authority
CN
China
Prior art keywords
recycled aggregate
modifier
polyvinyl alcohol
parts
concrete
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110715045.7A
Other languages
Chinese (zh)
Inventor
王晓英
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bbmg Cement Co ltd
Original Assignee
Bbmg Cement Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bbmg Cement Co ltd filed Critical Bbmg Cement Co ltd
Priority to CN202110715045.7A priority Critical patent/CN113480214A/en
Publication of CN113480214A publication Critical patent/CN113480214A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
    • C04B20/02—Treatment
    • C04B20/023—Chemical treatment
    • 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
    • C04B18/00—Use 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
    • C04B18/04—Waste materials; Refuse
    • C04B18/16—Waste materials; Refuse from building or ceramic industry
    • C04B18/167—Recycled materials, i.e. waste materials reused in the production of the same materials
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/91—Use of waste materials as fillers for mortars or concrete

Landscapes

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

Abstract

The application relates to the field of recycled aggregate modifiers, and particularly discloses a recycled aggregate modifier for concrete and a preparation method and a use method thereof. The recycled aggregate modifier is prepared by mixing the following raw materials in parts by mass: the preparation method comprises the following steps of mixing slag micro powder, water glass, nano silicon carbide, modifier mixing water, a suspending agent and a reinforcing agent: mixing the slag micro powder, the nano silicon carbide, the water glass and the modifier uniformly by using water, a suspending agent and a reinforcing agent, and then carrying out ultrasonic dispersion to obtain the modifier. The recycled aggregate modifier has the advantage of improving the strength of recycled aggregates.

Description

Recycled aggregate modifier for concrete and preparation method and use method thereof
Technical Field
The application relates to the field of recycled aggregate modifiers, in particular to a recycled aggregate modifier for concrete and a preparation method and a using method thereof.
Background
The recycled aggregate is prepared by crushing and screening waste concrete, and when the recycled aggregate is applied to the field of concrete, the mechanical property and durability of the prepared concrete are poor due to the characteristics of high water absorption and high porosity of the recycled aggregate, so that the application of the recycled aggregate is limited; the recycled aggregate modifier can strengthen the recycled aggregate, so that the performance of the recycled aggregate is enhanced.
At present, the related reinforcement measures for recycled aggregate mainly include: chemical solution infiltration strengthening, slurry filling strengthening, pre-water absorption filling strengthening, physical shaping strengthening, in-situ strengthening, microorganism strengthening, ultrasonic cleaning strengthening, high-concentration carbon dioxide strengthening and the like.
In view of the above-mentioned related technologies, the inventors believe that a large number of micro-cracks exist in the recycled aggregate during the crushing and screening processes, which results in poor mechanical properties of the recycled aggregate, and the related modifier only modifies and strengthens the surface of the recycled aggregate, and the micro-cracks in the recycled aggregate are not effectively filled, so that the modifying effect of the modifier on the recycled aggregate is poor.
Disclosure of Invention
In order to improve the mechanical property of recycled aggregate, the application provides a recycled aggregate modifier for concrete and a preparation method and a using method thereof.
In a first aspect, the application provides a recycled aggregate modifier for concrete, which adopts the following technical scheme:
the recycled aggregate modifier for concrete is prepared by mixing the following raw materials in parts by mass:
10-20 parts of slag micro powder with the particle size of 5-10 mu m,
20-30 parts of water glass,
2-3 parts of nano silicon carbide with the particle size of 500-600nm,
100 portions of water for mixing the modifier and 110 portions of water.
By adopting the technical scheme, the nano silicon carbide has the advantages of high mechanical strength and good wear resistance, hydration heat is generated when the recycled aggregate and the concrete raw material are hydrated, and the coefficient of thermal expansion of the nano silicon carbide is small, so that cracking of the recycled aggregate can be effectively reduced, cracking resistance of the recycled aggregate is improved, and strength of the recycled aggregate is improved.
The nano silicon carbide has large specific surface area and stable chemical property, can be used as a carrier of slag micropowder, can be filled in microcracks of the recycled aggregate together with water glass, and can improve the strength of the recycled aggregate.
The nano silicon carbide can modify the water glass, so that the size of the water glass colloid is smaller, and the water glass colloid can more easily and uniformly enter pores of a mortar layer on the surface of the recycled aggregate. After the nano silicon carbide is doped into the water glass, the microstructure of the recycled aggregate after the strengthening treatment can be improved.
The hydration product of the slag micro powder can automatically fill the microcracks of the recycled aggregate, the water glass solution can promote the hydration of the slag micro powder, and the water glass solution and the hydration product of the slag micro powder are mixed and interwoven to form a composite cementing material to fill the cracks of the recycled aggregate, so that the overall structural strength of the recycled aggregate is improved.
After the water glass enters the pores of the cement mortar on the surface of the recycled aggregate, the water glass is gradually hardened along with the time extension, and then sodium silicate gel is precipitated to repair the cracks of the recycled aggregate, so that the purpose of hole sealing is achieved, the surface density and the stacking density of the recycled aggregate are increased, and the strength of the recycled aggregate is improved.
The particle size of the nano silicon carbide is smaller than that of the recycled aggregate, and the nano silicon carbide can be doped into the water glass to refine the glue particles of the water glass, so that the water glass can better strengthen the recycled aggregate and fill the microcracks of the recycled aggregate.
The slag micro powder fills the microcracks of the recycled aggregate through hydration products of the slag micro powder, the smaller the particle size of the slag micro powder is, the common filling effect is achieved, the larger the particle size of the slag micro powder is, the more easily the pores on the surface of the recycled aggregate are directly plugged, the difficulty in filling the microcracks in the recycled aggregate is caused, the slag micro powder with the proper particle size automatically fills the microcracks in the recycled aggregate after hydration reaction, the integral strength of the recycled aggregate can be effectively improved, and the mechanical property of the recycled aggregate is improved.
Preferably, 5-10 parts of suspending agent is also included.
By adopting the technical scheme, the addition of the suspending agent can improve the dispersibility of the solid raw materials in water in the whole modifier system, so that the modification effect of the modifier is better.
Preferably, the suspending agent is polyvinyl alcohol.
By adopting the technical scheme, the polyvinyl alcohol is a high molecular polymer, the porosity of the recycled aggregate can be effectively reduced after the recycled aggregate is soaked in the polyvinyl alcohol solution, and the workability of the concrete can be improved after the modified recycled aggregate is mixed with other concrete raw materials, so that the strength of the recycled aggregate concrete is improved.
Meanwhile, the polyvinyl alcohol can promote the hydration of the slag micro powder, so that the slag micro powder can be better filled in the microcracks of the recycled aggregate, and the modification effect of the recycled aggregate is improved. The polyvinyl alcohol is beneficial to enhancing the dispersibility of the slag micro powder and the nano silicon carbide in a solution system, the slag micro powder can be fixed on the nano silicon carbide by the polyvinyl alcohol, the surface of the recycled aggregate is wrapped by a polyvinyl alcohol film after the recycled aggregate is filled with hydration products of the slag micro powder, and the polyvinyl alcohol forms a hydrophobic film after being dissolved in water, so that the porosity and the water absorption of the recycled aggregate are reduced, and the mechanical property of the recycled aggregate is improved.
Preferably, the polyvinyl alcohol is added in a mode that the polyvinyl alcohol is dissolved into a polyvinyl alcohol solution, and then the polyvinyl alcohol solution is mixed with other modifier raw materials;
the polyvinyl alcohol solution is prepared by the following method: firstly, mixing polyvinyl alcohol and water for dissolving the polyvinyl alcohol according to the mass ratio of 1:9, keeping the mixture at the temperature of 90-100 ℃ for 1-1.2h, and cooling the mixture to obtain a polyvinyl alcohol solution.
By adopting the technical scheme, the polyvinyl alcohol solution can be better fused with raw materials such as nano silicon carbide, water glass and slag micropowder, and the polyvinyl alcohol solution can improve the suspension property of solid particles in the whole modifier system, so that the modifier can be fully contacted with the recycled aggregate, and the modification effect of the modifier is improved.
Preferably, the coating also comprises 5-10 parts of reinforcing agent.
By adopting the technical scheme, the reinforcing agent can further enhance the strength of the recycled aggregate and simultaneously enhance the compatibility of the modified recycled aggregate and the cement raw material, the hydrophobic film is formed on the surface of the modified recycled aggregate due to the addition of the polyvinyl alcohol, so that the compatibility is poor when the recycled aggregate and the concrete raw material are mixed, and the reinforcing agent can further enhance the compatibility of the recycled aggregate and the concrete raw material and improve the strength of the recycled aggregate concrete.
Preferably, the reinforcing agent is polyethylene terephthalate fiber.
By adopting the technical scheme, the polyethylene terephthalate fiber has strong compatibility, the polyethylene terephthalate fiber has small volume, and after entering gaps of the recycled aggregate, the polyethylene terephthalate fiber can form uniform support in the recycled aggregate, so that the cohesiveness between the recycled aggregate and the slag micro powder and the nano silicon carbide is enhanced, the density of the recycled aggregate is enhanced, and the cracking condition is reduced.
In a second aspect, the application provides a preparation method of a recycled aggregate modifier for concrete, which adopts the following technical scheme:
the preparation method of the recycled aggregate modifier for concrete comprises the following steps,
s1: uniformly mixing 10-20 parts of slag micro powder, 2-3 parts of nano silicon carbide, 20-30 parts of water glass, 100 parts of modifier mixing water, 5-10 parts of suspending agent and 5-10 parts of reinforcing agent, and performing ultrasonic dispersion for 15-20min to obtain the modifier.
By adopting the technical scheme, after the suspending agent and the reinforcing agent are added into the raw materials of the modifier, the modifier has better modification effect on the recycled aggregate, and the mechanical property of the recycled aggregate is improved.
Preferably, the preparation method of the recycled aggregate modifier for concrete comprises the following steps of, S1: firstly, mixing polyvinyl alcohol and water for dissolving the polyvinyl alcohol according to the mass ratio of 1:9, keeping the mixture at the temperature of 90-100 ℃ for 1-1.2h, and cooling the mixture to obtain a polyvinyl alcohol solution;
s2: and uniformly mixing the polyvinyl alcohol solution, 10-20 parts of slag micro powder, 2-3 parts of nano silicon carbide, 20-30 parts of water glass, 100 parts of modifier mixing water and 5-10 parts of reinforcing agent, and performing ultrasonic dispersion for 15-20min to obtain the modifier.
By adopting the technical scheme, the polyvinyl alcohol is added in a state of being dissolved into solution, the polyvinyl alcohol solution can be better fused with raw materials such as nano silicon carbide, water glass, slag micropowder and the like, and the polyvinyl alcohol solution can improve the suspension property of solid particles in the whole modifier system, so that the modifier can be fully contacted with the recycled aggregate, and the modification effect of the modifier is improved.
In a third aspect, the application provides a method for using a recycled aggregate modifier for concrete, which adopts the following technical scheme:
the use method of the recycled aggregate modifier for concrete comprises the following steps,
s1: crushing and screening the recycled aggregate to obtain 5-20mm recycled aggregate, and then putting the recycled aggregate into a modifier for soaking for 1-2h, wherein the soaking ratio of the modifier to the recycled aggregate is 1-3: 1.
by adopting the technical scheme, the recycled aggregate is placed into the modifier and soaked for 1-2h, which is beneficial to the full contact of the modifier and the recycled aggregate, so that the modifier fills micro cracks and pores of the recycled aggregate, the water absorption of the recycled aggregate is reduced, and the strength of the recycled aggregate is improved.
In summary, the present application has the following beneficial effects:
1. because the slag micro powder is adopted, the hydration product of the slag micro powder can automatically fill the microcracks of the recycled aggregate, the water glass solution can promote the hydration of the slag micro powder, and the water glass solution and the hydration product of the slag micro powder are mixed and interwoven to form the composite gelled material to fill the cracks of the recycled aggregate, so that the overall structural strength of the recycled aggregate is improved.
2. The nano silicon carbide is preferably adopted in the application, has the advantages of high mechanical strength and good wear resistance, can generate hydration heat when the recycled aggregate and the concrete raw material are hydrated, has a small thermal expansion coefficient, and can effectively reduce cracking of the recycled aggregate, improve cracking resistance of the recycled aggregate and improve strength of the recycled aggregate.
3. According to the method, after the polyvinyl alcohol is dissolved into the polyvinyl alcohol solution, the polyvinyl alcohol solution is mixed with the slag micro powder, the nano silicon carbide, the water glass and the modifier, the water, the suspending agent and the reinforcing agent are mixed, ultrasonic dispersion is carried out, the dispersibility of solid particles is improved, when the modifier is in contact with the recycled aggregate, the modifier can better modify and reinforce the recycled aggregate, and the mechanical property of the recycled aggregate is enhanced.
Detailed Description
The raw material sources are as follows:
name of raw materials Name of manufacturer Number plate/goods number
Slag micropowder Tangshan Industrial building materials Co Ltd S95
Water glass Hubeixin run de chemical Co., Ltd 1344-09-8
Nano silicon carbide Xia chemical technology (Shandong) Co., Ltd 409-21-2
Polyvinyl alcohol Beijing Happy-minded Biotechnology Ltd 9002-89-5
Methacrylic acid Nanjing Sivasker chemical Co Ltd 79-41-4
Methyl cellulose Shenzhen Boshun chemical Co Ltd 138169-43-4
Polyethylene terephthalate fiber Henan Tianfu chemical Co Ltd 25038-59-9
Polypropylene fiber Shanghai Chenshao Biotech Co Ltd 9003-07-0
Steel fiber BEIJING SINO-SINA BUILDING TECHNOLOGY Co.,Ltd. DT-1
Example 1
The recycled aggregate modifier for concrete is prepared by mixing the following raw materials by mass:
15kg of slag micro powder with the particle size of 8 mu m;
25kg of water glass, namely 25kg of water glass,
2.5kg of nano silicon carbide with the particle size of 550 nm;
105kg of water for mixing the modifier,
a preparation method of a recycled aggregate modifier for concrete comprises the following steps:
s1: mixing the slag micro powder, the nano silicon carbide, the water glass and the modifier with water, uniformly mixing, and performing ultrasonic dispersion for 20min to obtain the modifier.
A use method of a recycled aggregate modifier for concrete comprises the following steps:
s1: crushing and screening the recycled aggregate to obtain 10 +/-5 mm recycled aggregate, and then putting the recycled aggregate into a modifier for soaking for 1 hour, wherein the soaking ratio of the modifier to the recycled aggregate is 1:1, fishing out and drying after soaking.
Examples 2 to 3
A recycled aggregate modifier for concrete is based on example 1, and is different in raw material dosage.
The amounts of the raw materials used in examples 1 to 3 are shown in the table below.
TABLE 1 raw material amounts of examples 1 to 3
Example 1 Example 2 Example 3
Slag micropowder/kg 15 10 20
Slag micropowder particle size/mum 8 8 8
Water glass/kg 25 20 30
Nano silicon carbide/kg 2.5 2 3
Nano silicon carbide grain size/nm 550 550 550
Water for mixing modifier/kg 105 100 110
The test comprises the following steps:
1. mechanical property test of modified recycled aggregate
The modified recycled aggregate was tested according to the method specified in GB/T25177-2010 recycled coarse aggregate for concrete.
2. Recycled aggregate concrete strength test
The preparation method of the recycled aggregate concrete comprises the following steps of firstly soaking the recycled aggregate subjected to crushing and screening treatment and a modifier for 1h according to the proportion of 1:1, fishing out and airing, mixing 150kg of the modified recycled aggregate with 70kg of cement, 100kg of sand and 25kg of fly ash to prepare a standard concrete test block with the size of 150 mm-150 mm, and carrying out standard maintenance for 28 days.
After standard concrete test blocks with the size of 150mm x 150mm were subjected to standard culture for 28 days, the test was performed according to the method specified in GB/T50081-2019.
The test results are given in the table below.
TABLE II test results for modified recycled aggregates of examples 1-3
Example 1 Example 2 Example 3
Recycled aggregate apparent density (kg/m)-3) 2800 2758 2769
Recycled aggregate crush value/%) 9 12 13
As can be seen from the above table, the recycled aggregate of example 1 is superior in mechanical properties to those of examples 2 and 3, i.e., example 1 is compared with examples 2 to 3, and example 1 is the most preferable example.
Comparative example 1
A recycled aggregate modifier for concrete, which is based on example 1, is different in that the amount of fine slag powder is 0.
Comparative example 2
A recycled aggregate modifier for concrete, which is based on example 1, is different from the recycled aggregate modifier in that the amount of water glass is 0.
Comparative example 3
A recycled aggregate modifier for concrete, which is based on the recycled aggregate modifier in the embodiment 1, and is characterized in that the dosage of the nano silicon carbide is 0.
Comparative example 4
A recycled aggregate modifier for concrete is based on example 1, and is characterized in that recycled aggregates are not soaked by the modifier.
The recycled aggregates of comparative examples 1-4 were tested for comparison.
The test results are given in the table below.
TABLE III test results for modified recycled aggregates of comparative examples 1-4
Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4
Recycled aggregate apparent density (kg/m)-3) 2635 2649 2664 2503
Recycled aggregate crush value/%) 15 16 15 21
The combination of the example 1 and the comparative examples 1 to 4 and the combination of the second table and the third table shows that the mechanical property of the modified recycled aggregate of the example 1 is superior to that of the comparative examples 1 to 4, so that the nano silicon carbide added in the application has the advantages of high mechanical strength and good wear resistance, hydration heat is generated when the recycled aggregate and a concrete raw material are hydrated, and the coefficient of thermal expansion of the nano silicon carbide is small, so that the cracking of the recycled aggregate can be effectively reduced, the cracking resistance of the recycled aggregate is improved, and the strength of the recycled aggregate is improved.
The nano silicon carbide has large specific surface area and stable chemical property, can be used as a carrier of slag micropowder, can be filled in microcracks of the recycled aggregate together with water glass, and can improve the strength of the recycled aggregate.
The nano silicon carbide can modify the water glass, so that the size of the water glass colloid is smaller, and the water glass colloid can more easily and uniformly enter pores of a mortar layer on the surface of the recycled aggregate. After the nano silicon carbide is doped into the water glass, the microstructure of the recycled aggregate after the strengthening treatment can be improved.
The hydration product of the slag micro powder can automatically fill the microcracks of the recycled aggregate, the water glass solution can promote the hydration of the slag micro powder, and the water glass solution and the hydration product of the slag micro powder are mixed and interwoven to form a composite cementing material to fill the cracks of the recycled aggregate, so that the overall structural strength of the recycled aggregate is improved.
After the water glass enters the pores of the cement mortar, the water glass is gradually hardened along with the time extension, and then sodium silicate gel is precipitated to repair the cracks of the recycled aggregate, so that the purpose of hole sealing is achieved, the surface density and the stacking density of the recycled aggregate are increased, and the strength of the recycled aggregate is improved.
Comparative example 5
A recycled aggregate modifier for concrete is based on example 1, and is characterized in that the particle size of nano silicon carbide is 300 nm.
Comparative example 6
A recycled aggregate modifier for concrete is based on example 1, and is characterized in that the particle size of nano silicon carbide is 700 nm.
Example 4
A recycled aggregate modifier for concrete is based on example 1, and is characterized in that the particle size of nano silicon carbide is 500 nm.
Example 5
A recycled aggregate modifier for concrete is based on example 1, and is characterized in that the particle size of nano silicon carbide is 600 nm.
The modified recycled aggregates of comparative examples 5-6 and examples 4-5 were tested.
The test results are given in the table below.
TABLE IV test results for modified recycled aggregates of comparative examples 5-6 and examples 4-5
Comparative example 5 Comparative example 6 Example 4 Example 5
Recycled aggregate apparent density (kg/m)-3) 2649 2664 2758 2788
Recycled aggregate crush value/%) 16 15 12 11
By combining the example 1, the comparative examples 5-6 and the examples 4-5 and combining the second and fourth tables, it can be seen that the mechanical property of the recycled aggregate of the example 1 is superior to that of the comparative examples 5-6 and the examples 4-5, so that the particle size of the nano silicon carbide in the application is smaller than that of the recycled aggregate, and the nano silicon carbide can be used for thinning water glass colloidal particles after being doped into water glass, so that the water glass can better strengthen the recycled aggregate and fill the microcracks of the recycled aggregate.
Comparative example 7
A recycled aggregate modifier for concrete, which is based on example 1, except that the fine slag powder has a particle size of 3 μm.
Comparative example 8
A recycled aggregate modifier for concrete, which is based on example 1, except that the fine slag powder has a particle size of 15 μm.
Example 6
A recycled aggregate modifier for concrete, which is based on example 1, except that the fine slag powder has a particle size of 5 μm.
Example 7
A recycled aggregate modifier for concrete, which is based on example 1, except that the fine slag powder has a particle size of 10 μm.
The modified recycled aggregates of comparative examples 7-8 and examples 6-7 were tested.
The test results are given in the table below.
TABLE V test results for modified recycled aggregates of comparative examples 7 to 8 and examples 6 to 7
Comparative example 4 Comparative example 5 Example 6 Example 7
Recycled aggregate apparent density (kg/m)-3) 2654 2669 2763 2759
Recycled aggregate crush value/%) 16 16 11 12
It can be seen by combining example 1, comparative example 7-8 and example 6-7, and combining tables II and V that the mechanical properties of the recycled aggregate of example 1 are superior to those of comparative example 7-8 and example 6-7, so that the micro-cracks of the recycled aggregate are filled with the slag micro-powder through the hydration product of the slag micro-powder, the smaller the particle size of the slag micro-powder is, the general filling effect is achieved, the larger the particle size of the slag micro-powder is, the pores on the surface of the recycled aggregate are easily and directly blocked, the micro-cracks in the recycled aggregate are not easily filled, the slag micro-powder with the proper particle size automatically fills the micro-cracks in the recycled aggregate after hydration reaction, the overall strength of the recycled aggregate can be effectively improved, and the mechanical properties of the recycled aggregate are improved.
Example 8
Based on example 1, the recycled aggregate modifier for concrete is characterized in that the modifier further comprises 8kg of a suspending agent, wherein the suspending agent is polyvinyl alcohol, and the adding mode of the polyvinyl alcohol is as follows: uniformly mixing polyvinyl alcohol and polyvinyl alcohol dissolving water according to the mass ratio of 1:9, keeping the mixture at 95 ℃ for 1h, cooling the mixture to obtain a polyvinyl alcohol solution, uniformly mixing 8kg of the polyvinyl alcohol solution with other modifier raw materials, and performing ultrasonic dispersion for 15min to obtain the modifier.
Example 9
Based on example 1, the recycled aggregate modifier for concrete is characterized in that the modifier further comprises 5kg of a suspending agent, wherein the suspending agent is polyvinyl alcohol, and the adding mode of the polyvinyl alcohol is as follows: uniformly mixing polyvinyl alcohol and polyvinyl alcohol dissolving water according to the mass ratio of 1:9, keeping the mixture at 95 ℃ for 1h, cooling the mixture to obtain a polyvinyl alcohol solution, uniformly mixing 5kg of the polyvinyl alcohol solution with other modifier raw materials, and performing ultrasonic dispersion for 15min to obtain the modifier.
Example 10
Based on example 1, the recycled aggregate modifier for concrete is characterized in that the modifier further comprises 10kg of a suspending agent, wherein the suspending agent is polyvinyl alcohol, and the adding mode of the polyvinyl alcohol is as follows: uniformly mixing polyvinyl alcohol and polyvinyl alcohol dissolving water according to the mass ratio of 1:9, keeping the mixture at 95 ℃ for 1h, cooling the mixture to obtain a polyvinyl alcohol solution, uniformly mixing 10kg of the polyvinyl alcohol solution with other modifier raw materials, and performing ultrasonic dispersion for 15min to obtain the modifier.
The modified recycled aggregates of examples 8-10 were tested.
The test results are given in the table below.
TABLE VI test results for modified recycled aggregates of examples 8-10
Example 8 Example 9 Example 10 Example 1
Recycled aggregate apparent density (kg/m)-3) 2899 2876 2873 2800
Recycled aggregate crush value/%) 8 12 12 9
Water absorption test% 1.7 2.1 2.3 6.3
By combining the example 1 and the examples 8 to 10 and combining the table six, the mechanical property and the water absorption test of the examples 8 to 10 are better than those of the example 1, so that the dispersibility of the solid raw material in water in the whole modifier system can be improved by adding the suspending agent in the application, and the modification effect of the modifier is better.
Meanwhile, the polyvinyl alcohol solution can be better fused with raw materials such as nano silicon carbide, water glass, slag micropowder and the like, and the polyvinyl alcohol solution can improve the suspension property of solid particles in the whole modifier system, so that the modifier can be fully contacted with the recycled aggregate, and the modification effect of the modifier is improved.
Example 11
Based on example 1, the recycled aggregate modifier for concrete is characterized by further comprising 8kg of a suspending agent, wherein the suspending agent is polyvinyl alcohol, and the suspending agent is added in a manner of directly mixing with the raw materials of the modifier.
Comparative example 9
A recycled aggregate modifier for concrete, which is based on example 11 and is different from the recycled aggregate modifier in that methyl cellulose with equal mass is used for replacing polyvinyl alcohol.
Comparative example 10
A recycled aggregate modifier for concrete, which is based on example 11 and is different from the recycled aggregate modifier in that methacrylic acid with equal mass is used for replacing polyvinyl alcohol.
The modified recycled aggregates of comparative examples 9-10 were tested.
The test results are given in the table below.
TABLE VII test results for modified recycled aggregates of comparative examples 9-10
Comparative example 9 Comparative example 10 Example 11
Recycled aggregate apparent density (kg/m)-3) 2801 2804 2899
Recycled aggregate crush value/%) 10 11 8
Compressive strength/Mpa of recycled aggregate concrete 32 31 38
It can be seen by combining example 11, comparative examples 9-10 and table seven that the mechanical properties of the recycled aggregate of example 11 and the compressive strength of the recycled aggregate concrete are superior to those of comparative examples 9-10, so that the polyvinyl alcohol added in the invention is a high molecular polymer, the recycled aggregate can effectively reduce the porosity of the recycled aggregate after being soaked in the polyvinyl alcohol solution, and the workability of the concrete can be improved after the modified recycled aggregate is mixed with other concrete raw materials, thereby improving the strength of the recycled aggregate concrete.
Example 12
Based on example 1, the recycled aggregate modifier for concrete is characterized in that the modifier further comprises 8kg of a reinforcing agent, wherein the reinforcing agent is polyethylene terephthalate fiber, the reinforcing agent is added in a mode that the polyethylene terephthalate fiber is directly mixed with other raw materials of the modifier, and the modifier is obtained after ultrasonic dispersion is carried out for 15 min.
Example 13
Based on example 1, the recycled aggregate modifier for concrete is characterized in that the modifier further comprises 5kg of a reinforcing agent, wherein the reinforcing agent is polyethylene terephthalate fiber, the reinforcing agent is added in a mode that the polyethylene terephthalate fiber is directly mixed with other raw materials of the modifier, and the modifier is obtained after ultrasonic dispersion is carried out for 15 min.
Example 14
Based on example 1, the recycled aggregate modifier for concrete is characterized in that the modifier also comprises 10kg of reinforcing agent, wherein the reinforcing agent is polyethylene terephthalate fiber, the reinforcing agent is added in a mode that the polyethylene terephthalate fiber is directly mixed with other raw materials of the modifier, and the modifier is obtained after ultrasonic dispersion is carried out for 15 min.
Comparative example 11
A recycled aggregate modifier for concrete, which is based on example 12 and is characterized in that the reinforcing agent is steel fiber.
Comparative example 12
A recycled aggregate modifier for concrete, which is based on the recycled aggregate modifier in example 12 and is characterized in that a reinforcing agent is polypropylene fiber.
The modified recycled aggregates of comparative examples 11-12 and examples 12-14 were tested.
The test results are given in the table below.
TABLE eighthly test results for modified recycled aggregates of comparative examples 11-12 and examples 12-14
Example 12 Example 13 Example 14 Comparative example 11 Comparative example 12
Recycled aggregate apparent density (kg/m)-3) 2932 2923 2926 2856 2864
Recycled aggregate crush value/%) 8 9 9.5 11 10
Compressive strength/Mpa of recycled aggregate concrete 39 38 38.5 36 35
Combining example 1 and examples 12-14 with tables two and eight, it can be seen that the mechanical properties of examples 12-14 are superior to those of example 1 and the mechanical properties of example 12 are superior to those of examples 13-14, so that the reinforcing agent in the application can further enhance the strength of the recycled aggregate and the compatibility of the modified recycled aggregate and the cement raw material, and due to the addition of the polyvinyl alcohol, a hydrophobic film is formed on the surface of the modified recycled aggregate, so that the compatibility is poor when the recycled aggregate and the concrete raw material are mixed, and the reinforcing agent can further enhance the compatibility of the recycled aggregate and the concrete raw material and improve the strength of the recycled aggregate concrete.
It can be seen by combining example 12 and comparative examples 11-12 with tables two and eight that the mechanical properties of the modified recycled aggregate of example 12 are better than those of comparative examples 11-12, so that the polyethylene terephthalate fiber added in the application has strong compatibility, the volume of the polyethylene terephthalate fiber is small, and after the polyethylene terephthalate fiber enters gaps of the recycled aggregate, uniform support can be formed in the recycled aggregate, the adhesion between the recycled aggregate, the slag micropowder and the nano silicon carbide is enhanced, the density of the recycled aggregate is enhanced, and the cracking situation is reduced.
The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims (9)

1. The recycled aggregate modifier for concrete is characterized by being prepared by mixing the following raw materials in parts by weight:
10-20 parts of slag micro powder with the particle size of 5-10 mu m,
20-30 parts of water glass,
2-3 parts of nano silicon carbide with the particle size of 500-600nm,
100 portions of water for mixing the modifier and 110 portions of water.
2. The recycled aggregate modifier for concrete according to claim 1, wherein: also comprises 5-10 parts of suspending agent.
3. The recycled aggregate modifier for concrete according to claim 2, wherein: the suspending agent is polyvinyl alcohol.
4. The recycled aggregate modifier for concrete according to claim 3, wherein: the polyvinyl alcohol is added in a mode that the polyvinyl alcohol is dissolved into a polyvinyl alcohol solution, and then the polyvinyl alcohol solution is mixed with other modifier raw materials;
the polyvinyl alcohol solution is prepared by the following method: firstly, mixing polyvinyl alcohol and water for dissolving the polyvinyl alcohol according to the mass ratio of 1:9, keeping the mixture for 1-1.2 hours at the temperature of 90-100 ℃, and cooling to obtain a polyvinyl alcohol solution.
5. The recycled aggregate modifier for concrete according to claim 1, wherein: and also comprises 5-10 parts of reinforcing agent.
6. The recycled aggregate modifier for concrete according to claim 5, wherein: the reinforcing agent is polyethylene terephthalate fiber.
7. A method for preparing a recycled aggregate modifier for concrete according to any one of claims 1 to 6, wherein: comprises the following steps of (a) carrying out,
s1: uniformly mixing 10-20 parts of slag micro powder, 2-3 parts of nano silicon carbide, 20-30 parts of water glass, 100 parts of modifier mixing water, 5-10 parts of suspending agent and 5-10 parts of reinforcing agent, and performing ultrasonic dispersion for 15-20min to obtain the modifier.
8. A method for preparing a recycled aggregate modifier for concrete according to claim 4, wherein the method comprises the following steps: comprises the following steps of (a) carrying out,
s1: firstly, mixing polyvinyl alcohol and water for dissolving the polyvinyl alcohol according to the mass ratio of 1:9, keeping the mixture at the temperature of 90-100 ℃ for 1-1.2h, and cooling the mixture to obtain a polyvinyl alcohol solution;
s2: and uniformly mixing the polyvinyl alcohol solution, 10-20 parts of slag micro powder, 2-3 parts of nano silicon carbide, 20-30 parts of water glass, 100 parts of modifier mixing water and 5-10 parts of reinforcing agent, and performing ultrasonic dispersion for 15-20min to obtain the modifier.
9. A method of using the recycled aggregate modifier for concrete according to any one of claims 1 to 6, wherein: comprises the following steps of (a) carrying out,
s1: crushing and screening the recycled aggregate to obtain 5-20mm recycled aggregate, and then putting the recycled aggregate into a modifier for soaking for 1-2h, wherein the soaking ratio of the modifier to the recycled aggregate is 1-3: 1.
CN202110715045.7A 2021-06-26 2021-06-26 Recycled aggregate modifier for concrete and preparation method and use method thereof Pending CN113480214A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110715045.7A CN113480214A (en) 2021-06-26 2021-06-26 Recycled aggregate modifier for concrete and preparation method and use method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110715045.7A CN113480214A (en) 2021-06-26 2021-06-26 Recycled aggregate modifier for concrete and preparation method and use method thereof

Publications (1)

Publication Number Publication Date
CN113480214A true CN113480214A (en) 2021-10-08

Family

ID=77936065

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110715045.7A Pending CN113480214A (en) 2021-06-26 2021-06-26 Recycled aggregate modifier for concrete and preparation method and use method thereof

Country Status (1)

Country Link
CN (1) CN113480214A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006282479A (en) * 2005-04-04 2006-10-19 Kao Corp Recycled aggregate-modifying agent
CN109503067A (en) * 2018-11-19 2019-03-22 青岛崇置混凝土工程有限公司 Light aggregate concrete and preparation method thereof
CN110526610A (en) * 2019-08-13 2019-12-03 温州市三箭混凝土有限公司 A kind of High Strength Regenerated Concrete and preparation method thereof
CN111646751A (en) * 2020-06-08 2020-09-11 深圳市和志诚环保建材有限公司 Composite modified cement stable recycled aggregate base layer mixture and preparation method thereof
CN112500062A (en) * 2020-12-26 2021-03-16 靖江市恒生混凝土制造有限公司 Self-compacting concrete prepared from recycled aggregate and preparation method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006282479A (en) * 2005-04-04 2006-10-19 Kao Corp Recycled aggregate-modifying agent
CN109503067A (en) * 2018-11-19 2019-03-22 青岛崇置混凝土工程有限公司 Light aggregate concrete and preparation method thereof
CN110526610A (en) * 2019-08-13 2019-12-03 温州市三箭混凝土有限公司 A kind of High Strength Regenerated Concrete and preparation method thereof
CN111646751A (en) * 2020-06-08 2020-09-11 深圳市和志诚环保建材有限公司 Composite modified cement stable recycled aggregate base layer mixture and preparation method thereof
CN112500062A (en) * 2020-12-26 2021-03-16 靖江市恒生混凝土制造有限公司 Self-compacting concrete prepared from recycled aggregate and preparation method thereof

Similar Documents

Publication Publication Date Title
CN110540389B (en) High-performance recycled concrete and preparation process thereof
CN113735520B (en) Anti-cracking recycled concrete and preparation method thereof
CN112174603B (en) Anti-crack plastering mortar and preparation method thereof
CN114656206B (en) Nano-silica and basalt fiber synergistically enhanced recycled concrete and preparation method thereof
CN109970377B (en) Water-soluble organic polymer toughened slag-based geopolymer cementing material and preparation method thereof
CN112897956A (en) Environment-friendly inorganic artificial stone and preparation method thereof
CN110981400A (en) Low-shrinkage steam-curing-free self-compacting C140UHPC and preparation method thereof
CN111056794A (en) Ecological nano photocatalytic recycled concrete and preparation method thereof
CN113968686B (en) Regeneration method of waste concrete and modified regenerated concrete
CN114105561A (en) Recycled concrete based on inorganic fibers and preparation method thereof
CN112759329A (en) Recycled concrete and production process thereof
CN111978055A (en) Recycled concrete with excellent impermeability and preparation method thereof
CN114230289A (en) Green high-strength and high-toughness concrete and preparation process thereof
CN114315249B (en) Pervious concrete and preparation process thereof
CN115477503A (en) Regenerated environment-friendly concrete and preparation process thereof
CN114804740A (en) Preparation method of polymer concrete reinforced by hybrid fibers and nano materials
CN112573868B (en) Granite micro-powder geopolymer composite base and preparation method and application thereof
CN109608134B (en) Cement board and semi-dry method preparation process thereof
CN114477873B (en) Recycled aggregate self-compacting concrete and preparation method thereof
CN113480214A (en) Recycled aggregate modifier for concrete and preparation method and use method thereof
CN115448659A (en) Solid waste stainless steel slag recycled concrete based on early carbonization and early dry-wet cycle coupling effect and preparation method thereof
CN112592099A (en) Preparation method of additive for high-strength concrete
CN113603422A (en) Anti-cracking recycled concrete
CN113860813B (en) Recycled concrete adopting expansive soil modifier
CN117303810B (en) Fiber-reinforced regenerated sand high-temperature-resistant geopolymer and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20211008

RJ01 Rejection of invention patent application after publication