阅读说明：本技术 网状纤维砂及其制备方法 (Reticular fiber sand and preparation method thereof ) 是由 张宁 曾才敏 张晔桐 于 2020-11-27 设计创作，主要内容包括：本发明公开了一种网状纤维砂,包括内芯和外壳,所述的外壳,以重量份为单位,包括以下原料：水泥80-156份、砂子45-100份、纤维5-8份、膨润土10-24份、抑水剂3-6份、氟化钾15-32份、乙烯-四氟乙烯共聚物10-30份、碳酸氢钠52-70份、偶联剂1.4-3份、2-甲基丙烯酸乙酯6-10份、N,N-二乙基苯胺2-4份,所述的网状纤维砂是经过制备建筑废加气混凝土、制备外壳材料、制备球形颗粒,压蒸养护等步骤制成的。本发明的网状纤维砂的溶胀比达到84.6g/g以上,可快速胶凝,形成白色乳浊液,缩短胶凝时间,应用效果好,极大降低封堵风险,可大力推广应用。(The invention discloses reticular fiber sand which comprises an inner core and an outer shell, wherein the outer shell comprises the following raw materials in parts by weight: 80-156 parts of cement, 45-100 parts of sand, 5-8 parts of fiber, 10-24 parts of bentonite, 3-6 parts of a water inhibitor, 15-32 parts of potassium fluoride, 10-30 parts of ethylene-tetrafluoroethylene copolymer, 52-70 parts of sodium bicarbonate, 1.4-3 parts of a coupling agent, 6-10 parts of 2-ethyl methacrylate and 2-4 parts of N, N-diethylaniline, wherein the reticular fiber sand is prepared by the steps of preparing building waste aerated concrete, preparing a shell material, preparing spherical particles, autoclaving, maintaining and the like. The swelling ratio of the reticular fiber sand reaches above 84.6g/g, the reticular fiber sand can be quickly gelled to form white emulsion, the gelling time is shortened, the application effect is good, the plugging risk is greatly reduced, and the reticular fiber sand can be widely popularized and applied.)

1. The reticular fiber sand is characterized by comprising an inner core and an outer shell, wherein the outer shell comprises the following raw materials in parts by weight: 80-156 parts of cement, 45-100 parts of sand, 5-8 parts of fiber, 10-24 parts of bentonite, 3-6 parts of a water inhibitor, 15-32 parts of potassium fluoride, 10-30 parts of ethylene-tetrafluoroethylene copolymer, 52-70 parts of sodium bicarbonate, 1.4-3 parts of a coupling agent, 6-10 parts of 2-ethyl methacrylate and 2-4 parts of N, N-diethylaniline;

the preparation method of the reticular fiber sand comprises the following steps:

(1) crushing the building waste aerated concrete into particles with the particle size of less than or equal to 5.2mm to prepare the building waste aerated concrete;

(2) stirring cement, sand, fiber, bentonite, a water inhibiting agent, potassium fluoride, an ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, a coupling agent, 2-ethyl methacrylate and N, N-diethylaniline for 9-12min at the microwave power of 100-160W, the temperature of 50-60 ℃ and the rotating speed of 200-300r/min to prepare a shell material;

(3) pre-absorbing water of the building waste aerated concrete prepared in the step (1) until the water content is 13% -20%, putting the building waste aerated concrete into a balling plate, continuously rolling in the balling plate, spraying 40-70 parts by weight of styrene-acrylic emulsion to wet the surface of particles, and uniformly scattering the shell material prepared in the step (2) in a balling area to form spherical particles;

(4) standing the spherical particles prepared in the step (3) at the temperature of 42-53 ℃ for 1.2-1.6h, then carrying out pressure steaming and curing at the temperature of 95-108 ℃ and under the pressure of 6-10MPa for 12-16h, and then cooling to room temperature to prepare the reticular fiber sand.

2. The reticulated fiber sand of claim 1, wherein the inner core is construction waste aerated concrete.

3. A reticulated fibre sand as claimed in claim 1, wherein the shell has a thickness of 0.07-0.15 mm.

4. The reticulated fiber sand of claim 3, wherein the outer shell comprises the following raw materials in parts by weight: 125 parts of cement, 76 parts of sand, 7 parts of fiber, 18 parts of bentonite, 5 parts of a water inhibiting agent, 25 parts of potassium fluoride, 22 parts of ethylene-tetrafluoroethylene copolymer, 65 parts of sodium bicarbonate, 2.1 parts of a coupling agent, 8 parts of 2-ethyl methacrylate and 3 parts of N, N-diethylaniline.

5. A reticulated fibre sand as claimed in claim 1 or claim 4, wherein the sand is river sand.

6. The reticulated fiber sand of claim 5, wherein the river sand has a particle size of 5 to 40 μm.

7. A reticulated fibre grit as claimed in claim 1 or claim 4, wherein said fibres are basalt fibres.

8. The reticulated fiber sand of claim 1 or claim 4, wherein the water-suppressing agent is a linear methyl hydrogen polysiloxane.

9. A reticulated fiber sand as claimed in claim 1 or claim 4, wherein the coupling agent is coupling agent kh-560.

Technical Field

The invention belongs to the technical field of plugging, and particularly relates to reticular fiber sand and a preparation method thereof.

Background

The key problem of frequent burst water disasters in the tunnel construction process is that the occurrence mechanism of the burst water and collapse disasters of the tunnel in the karst area is very complex, and the requirements on the disaster control technical level are very high. Although related scholars at home and abroad research and develop different grouting materials aiming at different engineering problems, different treatment methods are provided. However, the karst water-rich area has the characteristics of strong water source supplement, complex geological structure, strong hydraulic communication, pressure state, large flow, high flow rate and the like, so that the existing grouting material and treatment technical system is lack of pertinence, effective plugging and reinforcement treatment of the disasters are difficult to realize, and the tunnel engineering construction and engineering operation are always in a high risk state.

The plugging sand used in the prior art has the problems of small swelling ratio and the like, and cannot meet the technical requirements of high-difficulty plugging, so that the development of the sand with extremely high swelling ratio and extremely short gelation time is developed to meet the application requirements, greatly reduce the risk, and become a new research trend.

Disclosure of Invention

The invention provides reticular fiber sand and a preparation method thereof, and aims to solve the problems that plugging in the prior art is small in swelling and the like.

In order to solve the technical problems, the invention adopts the following technical scheme:

the reticular fiber sand comprises an inner core and an outer shell, wherein the outer shell comprises the following raw materials in parts by weight: 80-156 parts of cement, 45-100 parts of sand, 5-8 parts of fiber, 10-24 parts of bentonite, 3-6 parts of a water inhibitor, 15-32 parts of potassium fluoride, 10-30 parts of ethylene-tetrafluoroethylene copolymer, 52-70 parts of sodium bicarbonate, 1.4-3 parts of a coupling agent, 6-10 parts of 2-ethyl methacrylate and 2-4 parts of N, N-diethylaniline.

The technical principle is as follows: the potassium fluoride can promote the foaming effect of the ethylene-tetrafluoroethylene copolymer and the sodium bicarbonate in the application of the reticular fiber sand in the technical field of plugging, and extremely many bubbles are introduced into the reticular fiber sand, and the tiny closed independent bubbles can stably exist and be uniformly distributed in the reticular fiber sand, so that the swelling ratio of the reticular fiber sand is improved. The sodium bicarbonate has the function of quick setting, can shorten the curing time of the reticular fiber sand, enables the reticular fiber sand to be coagulated in a short time, improves the swelling ratio of the reticular fiber sand, and shortens the gelation time. The ethylene-tetrafluoroethylene copolymer, the potassium fluoride and the sodium bicarbonate can form a net-shaped structure which is distributed disorderly in the net-shaped fiber sand, so that the solid-phase reaction is accelerated, the swelling ratio of the net-shaped fiber sand is improved, and the gelling time is shortened. In addition, under the coupling and promotion effects of the coupling agent kh-560 and the N, N-diethylaniline, the expanded ethylene-tetrafluoroethylene copolymer is effectively bonded by the 2-ethyl methacrylate in a crosslinking way, so that the ethylene-tetrafluoroethylene copolymer, the potassium fluoride and the sodium bicarbonate are promoted to form an elastic consolidation body, water absorption is promoted, the swelling ratio of the reticular fiber sand is improved, the gelation time is shortened, the application requirements can be met, and the risk is greatly reduced.

Preferably, the inner core is building waste aerated concrete.

Preferably, the thickness of the housing is 0.07-0.15 mm.

Preferably, the shell comprises the following raw materials in parts by weight: 125 parts of cement, 76 parts of sand, 7 parts of fiber, 18 parts of bentonite, 5 parts of a water inhibiting agent, 25 parts of potassium fluoride, 22 parts of ethylene-tetrafluoroethylene copolymer, 65 parts of sodium bicarbonate, 2.1 parts of a coupling agent, 8 parts of 2-ethyl methacrylate and 3 parts of N, N-diethylaniline.

Preferably, the sand is river sand.

Preferably, the river sand has a particle size of 5-40 μm.

Preferably, the fibers are basalt fibers.

Preferably, the water inhibitor is linear methyl hydrogen polysiloxane.

Preferably, the coupling agent is coupling agent kh-560.

The invention also provides a preparation method of the reticular fiber sand, which comprises the following steps:

(1) crushing the building waste aerated concrete into particles with the particle size of less than or equal to 5.2mm to prepare the building waste aerated concrete;

(2) stirring cement, sand, fiber, bentonite, a water inhibiting agent, potassium fluoride, an ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, a coupling agent, 2-ethyl methacrylate and N, N-diethylaniline for 9-12min at the microwave power of 100-160W, the temperature of 50-60 ℃ and the rotating speed of 200-300r/min to prepare a shell material;

(3) pre-absorbing water of the building waste aerated concrete prepared in the step (1) until the water content is 13% -20%, putting the building waste aerated concrete into a balling plate, continuously rolling in the balling plate, spraying 40-70 parts by weight of styrene-acrylic emulsion to wet the surface of particles, and uniformly scattering the shell material prepared in the step (2) in a balling area to form spherical particles;

(4) standing the spherical particles prepared in the step (3) at the temperature of 42-53 ℃ for 1.2-1.6h, then carrying out pressure steaming and curing at the temperature of 95-108 ℃ and under the pressure of 6-10MPa for 12-16h, and then cooling to room temperature to prepare the reticular fiber sand.

The invention has the following beneficial effects:

the invention adds potassium fluoride, ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, coupling agent kh-560, 2-ethyl methacrylate and N, N-diethylaniline into the reticular fiber sand, and the six materials are cooperated with each other, thereby synergistically improving the swelling ratio which reaches over 84.6g/g, and the gelation time is extremely short and is less than 37.8 s; the reticular fiber sand can be quickly gelled to form white emulsion, shortens the gelling time, has good application effect, greatly reduces the plugging risk, and can be widely popularized and applied.

Detailed Description

In order to facilitate a better understanding of the invention, the following examples are given to illustrate, but not to limit the scope of the invention.

In an embodiment, the reticulated fiber sand: the inner core is made of building waste aerated concrete, a layer of outer shell with the thickness of 0.07-0.15mm is wrapped outside the inner core, and the outer shell comprises the following raw materials in parts by weight: 80-156 parts of cement, 45-100 parts of sand, 5-8 parts of fiber, 10-24 parts of bentonite, 3-6 parts of a water inhibitor, 15-32 parts of potassium fluoride, 10-30 parts of ethylene-tetrafluoroethylene copolymer, 52-70 parts of sodium bicarbonate, 1.4-3 parts of a coupling agent, 6-10 parts of 2-ethyl methacrylate and 2-4 parts of N, N-diethylaniline; the sand is river sand with the particle size of 5-40 mu m; the fiber is basalt fiber; the water inhibiting agent is linear methyl hydrogen-containing polysiloxane; the coupling agent is a coupling agent kh-560;

the preparation method of the reticular fiber sand comprises the following steps:

(1) crushing the building waste aerated concrete into particles with the particle size of less than or equal to 5.2mm to prepare the building waste aerated concrete;

(2) stirring cement, sand, fiber, bentonite, a water inhibiting agent, potassium fluoride, an ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, a coupling agent, 2-ethyl methacrylate and N, N-diethylaniline for 9-12min at the microwave power of 100-160W, the temperature of 50-60 ℃ and the rotating speed of 200-300r/min to prepare a shell material;

(3) pre-absorbing water of the building waste aerated concrete prepared in the step (1) until the water content is 13% -20%, putting the building waste aerated concrete into a balling plate, continuously rolling in the balling plate, spraying 40-70 parts by weight of styrene-acrylic emulsion to wet the surface of particles, and uniformly scattering the shell material prepared in the step (2) in a balling area to form spherical particles;

(4) standing the spherical particles prepared in the step (3) at the temperature of 42-53 ℃ for 1.2-1.6h, then carrying out pressure steaming and curing at the temperature of 95-108 ℃ and under the pressure of 6-10MPa for 12-16h, and then cooling to room temperature to prepare the reticular fiber sand.

The following is a more specific example.

Example 1

A reticulated fiber sand: the inner core is made of building waste aerated concrete, a layer of outer shell with the thickness of 0.12mm is wrapped outside the inner core, and the outer shell comprises the following raw materials in parts by weight: 125 parts of cement, 76 parts of sand, 7 parts of fiber, 18 parts of bentonite, 5 parts of a water inhibiting agent, 25 parts of potassium fluoride, 22 parts of ethylene-tetrafluoroethylene copolymer, 65 parts of sodium bicarbonate, 2.1 parts of a coupling agent, 8 parts of 2-ethyl methacrylate and 3 parts of N, N-diethylaniline; the sand is river sand with the particle size of 8-32 mu m; the fiber is basalt fiber; the water inhibiting agent is linear methyl hydrogen-containing polysiloxane; the coupling agent is a coupling agent kh-560;

the preparation method of the reticular fiber sand comprises the following steps:

(1) crushing the building waste aerated concrete into particles with the particle size of less than or equal to 4.8mm to prepare the building waste aerated concrete;

(2) stirring cement, sand, fiber, bentonite, a water inhibiting agent, potassium fluoride, an ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, a coupling agent, 2-ethyl methacrylate and N, N-diethylaniline for 10min at the microwave power of 150W, the temperature of 56 ℃ and the rotating speed of 300r/min to prepare a shell material;

(3) pre-absorbing water of the building waste aerated concrete prepared in the step (1) until the water content is 18%, putting the building waste aerated concrete into a balling plate, continuously rolling the building waste aerated concrete in the balling plate, spraying 60 parts by weight of phenylpropyl emulsion to wet the surfaces of particles, uniformly scattering the shell material prepared in the step (2) into a balling area, and forming the shell material into spherical particles;

(4) and (4) standing the spherical particles prepared in the step (3) at the temperature of 50 ℃ for 1.5h, then carrying out pressure steaming and curing at the temperature of 102 ℃ and the pressure of 9MPa for 14h, and then cooling to room temperature to prepare the reticular fiber sand.

Example 2

A reticulated fiber sand: the inner core is made of building waste aerated concrete, a layer of outer shell with the thickness of 0.09mm is wrapped outside the inner core, and the outer shell comprises the following raw materials in parts by weight: 85 parts of cement, 50 parts of sand, 6 parts of fiber, 10 parts of bentonite, 3 parts of a water inhibiting agent, 16 parts of potassium fluoride, 12 parts of ethylene-tetrafluoroethylene copolymer, 55 parts of sodium bicarbonate, 1.6 parts of a coupling agent, 7 parts of 2-ethyl methacrylate and 2 parts of N, N-diethylaniline; the sand is river sand with the particle size of 8-36 mu m; the fiber is basalt fiber; the water inhibiting agent is linear methyl hydrogen-containing polysiloxane; the coupling agent is a coupling agent kh-560;

the preparation method of the reticular fiber sand comprises the following steps:

(1) crushing the building waste aerated concrete into particles with the particle size of less than or equal to 5mm to prepare the building waste aerated concrete;

(2) stirring cement, sand, fiber, bentonite, a water inhibiting agent, potassium fluoride, an ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, a coupling agent, 2-ethyl methacrylate and N, N-diethylaniline for 11min at the microwave power of 130W, the temperature of 52 ℃ and the rotating speed of 200r/min to prepare a shell material;

(3) pre-absorbing water of the building waste aerated concrete prepared in the step (1) until the water content is 15%, putting the building waste aerated concrete into a balling plate, continuously rolling the building waste aerated concrete in the balling plate, spraying 42 parts by weight of styrene-acrylic emulsion to wet the surface of particles, uniformly scattering the shell material prepared in the step (2) in a balling area, and forming spherical particles;

(4) and (4) standing the spherical particles prepared in the step (3) at 47 ℃ for 1.5h, then performing pressure steaming and curing at 98 ℃ and under the pressure of 7MPa for 15h, and then cooling to room temperature to prepare the reticular fiber sand.

Example 3

A reticulated fiber sand: the inner core is made of building waste aerated concrete, a layer of outer shell with the thickness of 0.14mm is wrapped outside the inner core, and the outer shell comprises the following raw materials in parts by weight: 150 parts of cement, 96 parts of sand, 7 parts of fiber, 20 parts of bentonite, 5 parts of a water inhibiting agent, 26 parts of potassium fluoride, 28 parts of ethylene-tetrafluoroethylene copolymer, 65 parts of sodium bicarbonate, 2.7 parts of a coupling agent, 10 parts of 2-ethyl methacrylate and 4 parts of N, N-diethylaniline; the sand is river sand with the particle size of 10-29 mu m; the fiber is basalt fiber; the water inhibiting agent is linear methyl hydrogen-containing polysiloxane; the coupling agent is a coupling agent kh-560;

the preparation method of the reticular fiber sand comprises the following steps:

(1) crushing the building waste aerated concrete into particles with the particle size of less than or equal to 3.8mm to prepare the building waste aerated concrete;

(2) stirring cement, sand, fiber, bentonite, a water inhibiting agent, potassium fluoride, an ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, a coupling agent, 2-ethyl methacrylate and N, N-diethylaniline for 10min at the microwave power of 155W, the temperature of 58 ℃ and the rotating speed of 200r/min to prepare a shell material;

(3) pre-absorbing water of the building waste aerated concrete prepared in the step (1) until the water content is 15%, putting the building waste aerated concrete into a balling plate, continuously rolling the building waste aerated concrete in the balling plate, spraying 64 parts by weight of styrene-acrylic emulsion to wet the surfaces of particles, uniformly scattering the shell material prepared in the step (2) in a balling area, and forming spherical particles;

(4) and (4) standing the spherical particles prepared in the step (3) at 52 ℃ for 1.3h, then carrying out pressure steaming and curing at 106 ℃ and 9MPa for 15h, and then cooling to room temperature to prepare the reticular fiber sand.

Comparative example 1

The process for making reticulated fiber sand of example 1 was substantially the same except that the starting materials were absent potassium fluoride, ethylene tetrafluoroethylene copolymer, sodium bicarbonate, coupling agent kh-560, ethyl-2-methacrylate, and N, N-diethylaniline.

Comparative example 2

The process for making the reticulated fiber sand of example 1 was essentially the same except that potassium fluoride was absent from the starting material.

Comparative example 3

The process for making the reticulated grit of example 1 was essentially the same except that the ethylene tetrafluoroethylene copolymer was absent from the starting material.

Comparative example 4

The process for making the reticulated grit of example 1 was substantially the same except that the raw material was absent of sodium bicarbonate.

Comparative example 5

The process for making the reticulated grit of example 1 was substantially the same except that the coupling agent kh-560 was absent from the raw material.

Comparative example 6

The process for making the reticulated grit of example 1 was essentially the same except that the starting material was absent of ethyl 2-methacrylate.

Comparative example 7

The process for making the reticulated grit of example 1 was essentially the same except that the N, N-diethylaniline was absent from the feed.

The reticular fiber sands prepared according to the preparation processes described in examples 1-3 and comparative examples 1-7 were examined for bulk density, swelling ratio, and gel time, and the results are shown in the following table:

the method for testing the swelling ratio Sw of the reticular fiber sand comprises the following steps: 1g of reticular fiber sand is put into a 400-mesh gauze and immersed into the aqueous solution, after the material fully absorbs water and expands, the residual water on the surface is filtered by filter paper, and the change condition of the water absorption quality is recorded. The swelling ratio Sw (unit: (g/g)) is calculated from the following formula:

wherein M is_oAnd M_nThe mass of the dry and post-imbibition reticulated fibre sand, respectively.

Wherein the reticular fiber sand reacts with ten times of water, and the gel time test method comprises the following steps: accurately weighing 10g of reticular fiber sand in a beaker, adding 100ml of water, and recording the time t when the water is added₁And stirred rapidly and uniformly (about 10 seconds) and then left to stand to obtain a white emulsion, and then the change of the viscosity is continuously detected by a glass rod. When the glass rod is separated from the liquid level and the drawing phenomenon appears, the sample is already gelatinized, and t is recorded₂The gel time t is t ═ t₂-t₁。

Experimental groups	Swelling ratio (g/g)	Gel time(s)
			Example 1	92.1	34.4
Example 2	84.6	37.8
			Example 3	89.3	32.7
Comparative example 1	18.2	/
			Comparative example 2	81.4	/
Comparative example 3	79.7	/
			Comparative example 4	82.1	/
Comparative example 5	83.9	/
			Comparative example 6	80.6	/
Comparative example 7	82.8	/

From the above table, it can be seen that: (1) as can be seen from the data of examples 1-3, the swelling ratio of the reticular fiber sand is extremely high, and reaches above 84.6g/g, the gelation time is extremely short, and is below 37.8 s; the reticular fiber sand can be gelled quickly to form white emulsion, so that the gelling time is shortened, and the application effect is good.

(2) From the data of example 1 and comparative examples 1-7, it can be seen that potassium fluoride, ethylene tetrafluoroethylene copolymer, sodium bicarbonate, coupling agent kh-560, ethyl-2-methacrylate, N-diethylaniline, act synergistically in preparing the reticulated fiber sand, synergistically increasing the swell ratio because: the potassium fluoride can promote the foaming effect of the ethylene-tetrafluoroethylene copolymer and the sodium bicarbonate in the application of the reticular fiber sand in the technical field of plugging, and extremely many bubbles are introduced into the reticular fiber sand, and the tiny closed independent bubbles can stably exist and be uniformly distributed in the reticular fiber sand, so that the swelling ratio of the reticular fiber sand is improved. The sodium bicarbonate has the function of quick setting, can shorten the curing time of the reticular fiber sand, enables the reticular fiber sand to be coagulated in a short time, improves the swelling ratio of the reticular fiber sand, and shortens the gelation time. The ethylene-tetrafluoroethylene copolymer, the potassium fluoride and the sodium bicarbonate can form a net-shaped structure which is distributed disorderly in the net-shaped fiber sand, so that the solid-phase reaction is accelerated, the swelling ratio of the net-shaped fiber sand is improved, and the gelling time is shortened. In addition, under the coupling and promoting effects of the coupling agent kh-560 and the N, N-diethylaniline, the expanded ethylene-tetrafluoroethylene copolymer is effectively bonded by the 2-ethyl methacrylate in a crosslinking way, so that the ethylene-tetrafluoroethylene copolymer, the potassium fluoride and the sodium bicarbonate are promoted to form an elastic consolidation body, the water absorption is further promoted, and the swelling ratio of the reticular fiber sand is improved. According to the invention, potassium fluoride, ethylene-tetrafluoroethylene copolymer, sodium bicarbonate, coupling agent kh-560, 2-ethyl methacrylate and N, N-diethylaniline are added into the reticular fiber sand, and are cooperated with each other, so that the swelling ratio is synergistically improved.

The above description should not be taken as limiting the invention to the embodiments, but rather, as will be apparent to those skilled in the art to which the invention pertains, numerous simplifications or substitutions may be made without departing from the spirit of the invention, which shall be deemed to fall within the scope of the invention as defined by the claims appended hereto.