CN112939499A - Preparation method and application of modified silica fume material - Google Patents
Preparation method and application of modified silica fume material Download PDFInfo
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- CN112939499A CN112939499A CN202110126069.9A CN202110126069A CN112939499A CN 112939499 A CN112939499 A CN 112939499A CN 202110126069 A CN202110126069 A CN 202110126069A CN 112939499 A CN112939499 A CN 112939499A
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- silica fume
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- 229910021487 silica fume Inorganic materials 0.000 title claims abstract description 152
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical class O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 71
- 239000000463 material Substances 0.000 title claims abstract description 48
- 238000002360 preparation method Methods 0.000 title claims abstract description 15
- 239000004568 cement Substances 0.000 claims abstract description 59
- 239000010881 fly ash Substances 0.000 claims abstract description 45
- 239000006087 Silane Coupling Agent Substances 0.000 claims abstract description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 31
- 239000006185 dispersion Substances 0.000 claims abstract description 23
- 239000008367 deionised water Substances 0.000 claims abstract description 20
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 20
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 19
- 238000003756 stirring Methods 0.000 claims abstract description 16
- 239000007788 liquid Substances 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 14
- 239000000413 hydrolysate Substances 0.000 claims abstract description 13
- 238000001914 filtration Methods 0.000 claims abstract description 7
- 238000000227 grinding Methods 0.000 claims abstract description 7
- 238000005406 washing Methods 0.000 claims abstract description 7
- 238000001035 drying Methods 0.000 claims abstract description 6
- 238000003760 magnetic stirring Methods 0.000 claims description 8
- 238000007789 sealing Methods 0.000 claims description 6
- XDLMVUHYZWKMMD-UHFFFAOYSA-N 3-trimethoxysilylpropyl 2-methylprop-2-enoate Chemical compound CO[Si](OC)(OC)CCCOC(=O)C(C)=C XDLMVUHYZWKMMD-UHFFFAOYSA-N 0.000 claims description 5
- 239000003517 fume Substances 0.000 claims description 5
- 239000000377 silicon dioxide Substances 0.000 claims description 4
- 238000001291 vacuum drying Methods 0.000 claims description 4
- WYTZZXDRDKSJID-UHFFFAOYSA-N (3-aminopropyl)triethoxysilane Chemical compound CCO[Si](OCC)(OCC)CCCN WYTZZXDRDKSJID-UHFFFAOYSA-N 0.000 claims description 3
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 3
- PHQOGHDTIVQXHL-UHFFFAOYSA-N n'-(3-trimethoxysilylpropyl)ethane-1,2-diamine Chemical compound CO[Si](OC)(OC)CCCNCCN PHQOGHDTIVQXHL-UHFFFAOYSA-N 0.000 claims description 2
- 239000002245 particle Substances 0.000 abstract description 13
- 229910052710 silicon Inorganic materials 0.000 abstract description 8
- 239000010703 silicon Substances 0.000 abstract description 8
- 239000004566 building material Substances 0.000 abstract description 2
- 238000009826 distribution Methods 0.000 abstract description 2
- FZHAPNGMFPVSLP-UHFFFAOYSA-N silanamine Chemical compound [SiH3]N FZHAPNGMFPVSLP-UHFFFAOYSA-N 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 10
- 238000002156 mixing Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000036571 hydration Effects 0.000 description 5
- 238000006703 hydration reaction Methods 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 208000028659 discharge Diseases 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 239000011398 Portland cement Substances 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 230000000051 modifying effect Effects 0.000 description 3
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000007385 chemical modification Methods 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 238000003921 particle size analysis Methods 0.000 description 2
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 229920013822 aminosilicone Polymers 0.000 description 1
- 239000002956 ash Substances 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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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
- C04B7/00—Hydraulic cements
- C04B7/14—Cements containing slag
- C04B7/147—Metallurgical slag
-
- 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
- C04B18/14—Waste materials; Refuse from metallurgical processes
- C04B18/146—Silica fume
-
- 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
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/0006—Waste inorganic 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
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
-
- 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
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
-
- 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
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Environmental & Geological Engineering (AREA)
- Inorganic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Civil Engineering (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
The invention relates to a preparation method of a modified silica fume material, belonging to the technical field of building materials, and the method comprises the following steps of firstly, adding silica fume into absolute ethyl alcohol, and uniformly dispersing to obtain silica fume dispersion liquid; and then adding a silane coupling agent into deionized water, adding the prepared silane coupling agent hydrolysate into the silica fume dispersion liquid, placing the silica fume dispersion liquid in a water bath at the temperature of 60-80 ℃, magnetically stirring, filtering, washing filter residues with deionized water, finally drying in vacuum, and grinding to obtain the modified silica fume material. According to the invention, the silica fume is modified by adopting the silane coupling agent, the aminosilane reacts with silicon hydroxyl on the silica fume, the Zeta potential on the surface of the silica fume is changed, negative charge is changed into positive charge, the steric hindrance between silica fume particles is increased, the number of large particles of the modified silica fume is reduced, the particle size distribution is more concentrated, after the modified silica fume is doped into the fly ash cement, the fluidity of fly ash cement paste is improved, the dispersibility of the modified silica fume is improved, and the early strength of the fly ash cement is increased.
Description
Technical Field
The invention relates to a preparation method of a modified silica fume material, belonging to the technical field of building materials.
Background
The fly ash cement is cement mixed by fly ash and ordinary portland cement, and compared with the ordinary portland cement, the fly ash cement has the advantages of low hydration heat, small drying shrinkage and high later strength due to the fly ash, but the early strength is greatly reduced. And meanwhile, the pozzolanic admixture has higher activity than fly ash, and the silica fume is added into fly ash cement to help the development of early strength.
The silica fume, also called silica fume, is a derivative produced in the industrial production of ferrosilicon metal, usually SiO in the silica fume2The content of (A) is higher than 80%. Replacing cement with proper amount of silica fume, the silica fume will produce volcanic ash and micro aggregate effect in the cement slurry, and during the early stage of hydration, the silica fume is mixed with Ca (OH)2The reaction is carried out to form C-S-H gel, the number of macropores is reduced, the structural density is increased, and the early strength of the fly ash cement is improved. However, silica fume has small particles and a large specific surface area, and is easily agglomerated, and is difficult to be uniformly dispersed by a conventional dispersion method, so that the properties of the silica fume cannot be fully exerted. Therefore, how to improve the dispersibility of silica fume particles is a key point for realizing excellent physical and chemical properties thereof.
The prior art relating to silica fume dispersion methods is: according to the Chinese patent application with the application number of CN202010227731.5, silicon micropowder is added into a certain amount of water to obtain a silicon micropowder solution, a discharge gap is determined, a liquid-electric effect device is connected with two ends of the discharge gap, the solution is subjected to discharge treatment until the agglomeration phenomenon of the silicon micropowder is improved, the discharge is stopped, and the obtained solution is dried to obtain silicon micropowder powder. The silica fume dispersing method has a complex flow, and is easy to generate secondary agglomeration when being doped into cement slurry with high alkalinity, so that the compactness of a cement matrix can be reduced; the Chinese patent application with the application number of CN201510975172.5 discloses a silica fume dispersion modification method, which comprises the steps of using Ca (OH) with certain concentration2The solution is used for pretreating the surface of the silica fume to change the electronegativity of the surface of the silica fume into the electropositivity, so that a better dispersion effect is realizedCa(OH)2In solution by reaction with Ca (OH)2The surface charge of the silica fume is modified by reaction, and the silica fume is consumed to a certain extent in the reaction process, so that the subsequent improvement of the performance of the cement matrix is not facilitated, and the method has certain limitation. Some researchers also adopt mechanical ball milling and ultrasonic dispersion of silica fume, and the use effect in the cement-based material is not good finally. It is therefore of particular importance to find a way to achieve a better dispersion of the silica fume in the cement matrix.
Disclosure of Invention
The invention aims to solve the defects and provides a preparation method of a modified silica fume material, and the modified silica fume material prepared by the method has a good dispersion effect in a cement matrix and can effectively improve the performance of the cement matrix.
Technical scheme
A preparation method of a modified silica fume material comprises the following steps:
(1) adding silica fume into absolute ethyl alcohol, and uniformly dispersing by ultrasonic to obtain silica fume dispersion liquid;
(2) adding a silane coupling agent into deionized water, and uniformly stirring to obtain silane coupling agent hydrolysate;
(3) adding silane coupling agent hydrolysate into the silica fume dispersion liquid obtained in the step (1), sealing a container opening, placing the container opening in a water bath at the temperature of 60-80 ℃, performing magnetic stirring, filtering after stirring, washing filter residue with deionized water, finally drying the filter residue in vacuum, and grinding to obtain the modified silica fume material.
In the step (1), SiO in the silica fume2The content is more than 96 percent;
in the step (2), the mass of the silane coupling agent is 0.4-0.8% of the mass of the silica fume.
Further, in the step (1), the mass ratio of the silica fume to the absolute ethyl alcohol is 1: (2-4).
Further, in the step (1), the power of ultrasonic dispersion is 50-70 w, the frequency is 40-60 KHz, and the time is 6-10 min.
Further, in the step (2), the silane coupling agent is any one selected from the group consisting of N- (β -aminoethyl) - γ -aminopropyltrimethoxysilane (KH792), γ -aminopropyltriethoxysilane (KH550), and γ -methacryloxypropyl-trimethoxysilane (KH570), and more preferably, KH 550.
Further, in the step (2), the mass of the deionized water is 50-60% of the mass of the absolute ethyl alcohol.
Further, in the step (2), the stirring speed is 100-150 r/min.
Further, in the step (3), the rotating speed of the magnetic stirring is 850-950 r/min.
Further, in the step (3), the vacuum drying temperature is 50-60 ℃.
The application of the modified silica fume material in preparing the fly ash cement comprises the following steps: uniformly mixing 330-355 parts of cement, 25-50 parts of modified silica fume material and 125-155 parts of fly ash to obtain the fly ash cement.
The invention has the beneficial effects that:
(1) according to the invention, silane coupling agent is adopted to carry out surface chemical modification on the silica fume, aminosilane reacts with silicon hydroxyl on the silica fume, Zeta potential on the surface of the silica fume changes, negative charge is changed into positive charge, steric hindrance between silica fume particles is increased, the number of large particles of the modified silica fume is reduced, particle size distribution is more concentrated, and after the modified silica fume is doped into fly ash cement, the fluidity of fly ash cement paste is improved, and the dispersibility of the modified silica fume is improved.
(2) The modified silica fume has better pozzolanic effect and filling effect, and in the fly ash cement slurry with electronegativity, the modified silica fume can be better combined with cement particles to promote early hydration, so that the hardened slurry structure becomes more compact, and the early strength of the fly ash cement is increased.
Drawings
FIG. 1 is an X-ray diffraction pattern of the modified silica fume material prepared in example 1;
FIG. 2 is a FT-IR plot of a modified silica fume material made in example 1;
FIG. 3 is a graph of particle size analysis of the modified silica fume material obtained in example 1.
Detailed Description
The technical solution of the present invention is further explained with reference to the accompanying drawings and specific embodiments.
In the following examples, SiO is contained in the silica fume2The content is more than 96 percent; the cement is PII 52.5 Portland cement, and the median diameter is 10.62 mu m; specific surface area of 1.132m2(ii)/g; the fly ash is second-grade fly ash, the median diameter is 9.75 mu m, and the specific surface area is 0.813m2(ii) g, but is not limited thereto.
Example 1
A preparation method of a modified silica fume material comprises the following steps:
(1) adding silica fume into absolute ethyl alcohol, wherein the mass ratio of the silica fume to the absolute ethyl alcohol is 1: 4, ultrasonically dispersing uniformly to obtain a silica fume dispersion liquid;
(2) adding a silane coupling agent KH550 into deionized water, wherein the mass of the silane coupling agent is 0.4% of that of the silica fume, the mass of the deionized water is 50% of that of the absolute ethyl alcohol, and uniformly stirring at a rotating speed of 100r/min to obtain silane coupling agent hydrolysate;
(3) adding silane coupling agent hydrolysate into the silica fume dispersion liquid obtained in the step (1), sealing a container opening, placing the container opening in a water bath at 70 ℃, performing magnetic stirring (the rotating speed is 900r/min, the time is 1.5h), filtering after stirring, washing filter residue with deionized water, finally drying the filter residue in vacuum at 60 ℃, and grinding to obtain the modified silica fume material.
The modified silica fume material is used for preparing fly ash cement: and uniformly mixing 335 parts of cement, 40 parts of modified silica fume material and 150 parts of fly ash to obtain the fly ash cement.
Fig. 1 is an X-ray diffraction pattern of the modified silica fume material obtained in example 1, and it can be seen that XRD pattern curves of the original silica fume and the modified silica fume are substantially coincident, and a dispersion peak of an amorphous phase appears only in the vicinity of 2 θ ═ 22 °, which indicates that the phase composition of the silica fume itself is not significantly affected by the surface modification of the silica fume. In addition, silica fume exhibits weak diffraction peaks, which may be due to characteristic peaks of impurities in the silica fume, but are indistinguishable due to too weak signal.
FIG. 2 is a FT-IR plot of the modified silica fume material from example 1, showing the surface modificationAfter sex, the position and intensity of the absorption peak are obviously changed. At 2883cm-1A weak absorption peak appears at the position of-CH2C-H stretching vibration peak in (1). 1639cm-1Has a peak of-NH2The characteristic absorption of the deformation vibration in the N-H surface of the functional group, and a new characteristic peak-NH appears on the surface of the modified silica fume2and-CH2The KH550 silane coupling agent is covalently bonded with the surface of the silica fume, and the chemical modification is successful.
Fig. 3 is a particle size analysis diagram of the modified silica fume material prepared in example 1, and it can be seen that after surface modification, the accumulation rate of large particles of the modified silica fume is smaller than that of the original silica fume, the accumulation rate of medium particles is larger than that of the original silica fume, and the number of large particles in the silica fume is reduced to a certain extent after modification.
Example 2
A preparation method of a modified silica fume material comprises the following steps:
(1) adding silica fume into absolute ethyl alcohol, wherein the mass ratio of the silica fume to the absolute ethyl alcohol is 1: 3, uniformly dispersing by ultrasonic to obtain a silica fume dispersion liquid;
(2) adding a silane coupling agent KH792 into deionized water, wherein the mass of the silane coupling agent is 0.6% of that of the silica fume, the mass of the deionized water is 50% of that of the absolute ethyl alcohol, and uniformly stirring at a rotating speed of 100r/min to obtain silane coupling agent hydrolysate;
(3) adding silane coupling agent hydrolysate into the silica fume dispersion liquid obtained in the step (1), sealing the container opening, placing the container opening in a water bath at 60 ℃, performing magnetic stirring (the rotating speed is 900r/min, the time is 1h), filtering after stirring, washing filter residues with deionized water, finally performing vacuum drying on the filter residues at 60 ℃, and grinding to obtain the modified silica fume material.
The modified silica fume material is used for preparing fly ash cement: and uniformly mixing 335 parts of cement, 40 parts of modified silica fume material and 150 parts of fly ash to obtain the fly ash cement.
Example 3
A preparation method of a modified silica fume material comprises the following steps:
(1) adding silica fume into absolute ethyl alcohol, wherein the mass ratio of the silica fume to the absolute ethyl alcohol is 3: 7, ultrasonically dispersing uniformly to obtain a silica fume dispersion liquid;
(2) adding a silane coupling agent KH570 into deionized water, wherein the mass of the silane coupling agent is 0.8% of that of the silica fume, the mass of the deionized water is 50% of that of the absolute ethyl alcohol, and uniformly stirring at a rotating speed of 100r/min to obtain silane coupling agent hydrolysate;
(3) adding silane coupling agent hydrolysate into the silica fume dispersion liquid obtained in the step (1), sealing the container opening, placing the container opening in a water bath at 80 ℃, performing magnetic stirring (the rotating speed is 900r/min, the time is 2 hours), filtering after the stirring is finished, washing filter residues with deionized water, finally performing vacuum drying on the filter residues at 60 ℃, and grinding to obtain the modified silica fume material.
The modified silica fume material is used for preparing fly ash cement: and uniformly mixing 335 parts of cement, 40 parts of modified silica fume material and 150 parts of fly ash to obtain the fly ash cement.
Comparative example 1
A preparation method of a modified silica fume material comprises the following steps:
(1) adding silica fume into absolute ethyl alcohol, wherein the mass ratio of the silica fume to the absolute ethyl alcohol is 1: 3, uniformly dispersing by ultrasonic to obtain a silica fume dispersion liquid;
(2) adding a silane coupling agent KH550 into deionized water, wherein the mass of the silane coupling agent is 1% of that of the silica fume, the mass of the deionized water is 50% of that of the absolute ethyl alcohol, and uniformly stirring at a rotating speed of 100r/min to obtain silane coupling agent hydrolysate;
(3) adding silane coupling agent hydrolysate into the silica fume dispersion liquid obtained in the step (1), sealing a container opening, placing the container opening in a water bath at 70 ℃, performing magnetic stirring (the rotating speed is 900r/min, the time is 1.5h), filtering after stirring, washing filter residue with deionized water, finally drying the filter residue in vacuum at 60 ℃, and grinding to obtain the modified silica fume material.
The modified silica fume material is used for preparing fly ash cement: and uniformly mixing 335 parts of cement, 40 parts of modified silica fume material and 150 parts of fly ash to obtain the fly ash cement.
Comparative example 2
A preparation method of fly ash cement comprises the following steps: and uniformly mixing 335 parts of cement, 40 parts of undisturbed silica fume and 150 parts of fly ash to obtain the fly ash cement.
Comparative example 3
A preparation method of fly ash cement comprises the following steps: and (3) uniformly mixing 375 parts of cement and 150 parts of fly ash to obtain the fly ash cement.
And (3) performance testing:
1. the silica fume and the modified silica fume materials prepared in examples 1-3 were tested for surface charging and the results are shown in Table 1:
TABLE 1 surface electrification of silica fume
| Material | Zeta potential/mV |
| Silica fume | -64.6 |
| Example 1(KH550 modified silica fume) | 11.5 |
| Example 2(KH570 modified silica fume) | -31.7 |
| Example 3(KH792 modified silica fume) | -16.2 |
As can be seen from the test results in Table 1, the original-64.6 mV of the silica fume modified by KH550 is changed into +11.5mV, and the potential is increased from a negative value to a positive value because a large number of active silicon hydroxyl groups exist on the surface of the silica fume, when the silicon oxygen bonds on the aminosilicone meet the active silicon hydroxyl groups on the surface of the silica fume, the reaction occurs, and the positively charged amino groups are grafted on the surface of the silica fume, and KH792 and KH570 also have an effect on the surface charge of the silica fume but do not significantly change the electronegativity of the silica fume.
2. Uniformly stirring the fly ash cement of examples 1-3 and comparative examples 1-3 with 160 parts of water and 0.5625 part of polycarboxylic acid water reducing agent (the water reducing rate is more than 40%) respectively to obtain cement paste, testing the fluidity of the cement paste, pouring the cement paste into a six-combined steel mould with the thickness of 20mm multiplied by 20mm, trowelling the surface, placing the cement paste into a standard curing box for molding for 1d, and then demoulding; continuously placing the sample into a normal-temperature curing box for curing to a specified age, wherein the molding and curing conditions are as follows: the test samples are tested at the temperature of 25 ℃, the humidity of 100 percent and the age of 3d, 7d and 28d, and the results are shown in the table 2:
TABLE 2
As can be seen from Table 2, the cement test block 3d, which has a lower compressive strength than the blank (comparative example 3) after the silica fume has replaced part of the cement, fails to function at the beginning of hydration, and mainly plays a filling role, probably due to its own activity limitation. As hydration proceeded, the silica fume began to function and the 7d compressive strength of the silica fume doped test block was closer to or even better than that of the blank (comparative example 3) which was not doped with silica fume. By comparing examples 1, 2, 3 and comparative example 2, it can be seen that: (1) KH550 has better modifying effect on silica fume than KH792 and KH 570; (2) compared with the original-state silica fume, the fluidity of the fly ash cement paste is improved to a certain extent after the modified silica fume is doped; (3) the improvement effect of the modified silica fume on the compressive strength of the fly ash cement is better than that of the original silica fume, after the modified silica fume is modified by KH550, the compressive strengths of 3d, 7d, 14d and 28d are respectively improved by 8.14%, 9.17%, 11.03% and 8.46% compared with the comparative example 2, and the compressive strengths of 14d and 28d are respectively improved by 15.29% and 19.18% compared with the comparative example 3; (4) as can be seen from example 1 and comparative example 1, the silane coupling agent used for modifying the silica fume needs to be in a proper amount, and too much silane coupling agent has a negative effect. By modifying the surface of the silica fume particles, the dispersion effect of the silica fume in the cement is improved, the excellent characteristics of the silica fume are promoted to be exerted, the early-stage performance of the fly ash cement paste is improved, the fluidity is improved, and the structure becomes more compact. Therefore, the modified silica fume material provided by the invention has a positive effect on improving the early-stage macroscopic strength of the fly ash cement.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The preparation method of the modified silica fume material is characterized by comprising the following steps:
(1) adding silica fume into absolute ethyl alcohol, and uniformly dispersing by ultrasonic to obtain silica fume dispersion liquid;
(2) adding a silane coupling agent into deionized water, and uniformly stirring to obtain silane coupling agent hydrolysate;
(3) adding silane coupling agent hydrolysate into the silica fume dispersion liquid obtained in the step (1), sealing a container opening, placing the container opening in a water bath at 60-80 ℃, performing magnetic stirring, filtering after stirring, washing filter residue with deionized water, finally drying the filter residue in vacuum, and grinding to obtain a modified silica fume material;
in the step (1), SiO in the silica fume2The content is more than 96 percent;
in the step (2), the mass of the silane coupling agent is 0.4-0.8% of the mass of the silica fume.
2. The method for preparing the modified silica fume material according to claim 1, wherein in the step (1), the mass ratio of the silica fume to the absolute ethyl alcohol is 1: (2-4).
3. The preparation method of the modified silica fume material according to claim 1, wherein in the step (1), the power of the ultrasonic dispersion is 50-70 w, the frequency is 40-60 KHz, and the time is 6-10 min.
4. The method for preparing the modified silica fume material according to claim 1, wherein in the step (2), the silane coupling agent is selected from any one of N- (β -aminoethyl) - γ -aminopropyltrimethoxysilane, γ -aminopropyltriethoxysilane or γ -methacryloxypropyl-trimethoxysilane.
5. The method of claim 4, wherein the silane coupling agent is γ -aminopropyltriethoxysilane.
6. The method for preparing the modified silica fume material according to claim 1, wherein in the step (2), the mass of the deionized water is 50-60% of the mass of the absolute ethyl alcohol.
7. The method for preparing the modified silica fume material according to claim 1, wherein in the step (2), the stirring speed is 100 to 150 r/min.
8. The method for preparing the modified silica fume material according to claim 1, wherein in the step (3), the rotation speed of the magnetic stirring is 850-950 r/min.
9. The method for preparing a modified silica fume material according to any one of claims 1 to 8, wherein in the step (3), the vacuum drying temperature is 50 to 60 ℃.
10. The use of the modified silica fume material prepared by the method of any one of claims 1 to 9 in the preparation of fly ash cement, wherein 330 to 355 parts of cement, 25 to 50 parts of the modified silica fume material and 125 to 155 parts of fly ash are mixed uniformly to obtain the fly ash cement.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113416016A (en) * | 2021-06-29 | 2021-09-21 | 武汉理工大学 | Concrete anti-shrinkage carbon-based nano reinforcing agent and preparation method thereof |
| CN114573291A (en) * | 2022-02-25 | 2022-06-03 | 陕西越众混凝土有限公司 | Limestone powder high-strength concrete and preparation method thereof |
| CN116199477A (en) * | 2023-02-09 | 2023-06-02 | 广西大学 | UHPC (ultra high Performance) based on hydrolytic silane and preparation method thereof |
| CN116199481A (en) * | 2023-03-09 | 2023-06-02 | 浙江建信装饰有限公司 | Ultra-high performance concrete with low shrinkage and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1101018A (en) * | 1993-09-29 | 1995-04-05 | 山东矿业学院 | Ash-dreges mixed cement |
| CN106186759A (en) * | 2016-07-07 | 2016-12-07 | 济南大学 | A kind of based on the modified silicon ash surface scattered Nano-meter SiO_2 of preadsorption2application process in cement-based material |
-
2021
- 2021-01-29 CN CN202110126069.9A patent/CN112939499A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1101018A (en) * | 1993-09-29 | 1995-04-05 | 山东矿业学院 | Ash-dreges mixed cement |
| CN106186759A (en) * | 2016-07-07 | 2016-12-07 | 济南大学 | A kind of based on the modified silicon ash surface scattered Nano-meter SiO_2 of preadsorption2application process in cement-based material |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113416016A (en) * | 2021-06-29 | 2021-09-21 | 武汉理工大学 | Concrete anti-shrinkage carbon-based nano reinforcing agent and preparation method thereof |
| CN114573291A (en) * | 2022-02-25 | 2022-06-03 | 陕西越众混凝土有限公司 | Limestone powder high-strength concrete and preparation method thereof |
| CN116199477A (en) * | 2023-02-09 | 2023-06-02 | 广西大学 | UHPC (ultra high Performance) based on hydrolytic silane and preparation method thereof |
| CN116199481A (en) * | 2023-03-09 | 2023-06-02 | 浙江建信装饰有限公司 | Ultra-high performance concrete with low shrinkage and preparation method thereof |
| CN116199481B (en) * | 2023-03-09 | 2023-12-12 | 浙江建信装饰有限公司 | Ultra-high performance concrete with low shrinkage and preparation method thereof |
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