Intelligent response carrier modified hydrogel solidified soil and preparation method thereof

Abstract

The invention discloses intelligent response carrier modified hydrogel solidified soil and a preparation method thereof, and relates to the technical field of rigid matrix slope greening. Comprising the following components in parts by weight: 400 to 500 parts of soil, 1.5 to 3.3 parts of tetramethylethylenediamine, 25 to 50 parts of an ammonium persulfate solution, 2 to 4.2 parts of polyvinyl alcohol, 6 to 11 parts of acrylamide, 0.05 to 0.13 part of methylene bisacrylamide, 160 to 200 parts of water, 5 to 10 parts of solid paraffin, 15 to 30 parts of porous ceramsite, 5 to 10 parts of standard sand and 1 to 3 parts of nano silicon dioxide. According to the prepared intelligent response carrier modified hydrogel solidified soil, the modified hydrogel solidified soil has good flow retentivity, can be rapidly solidified under triggering of external response conditions, can form strength and is suitable for being used for spraying construction.

Description

Technical Field

[0001] The present invention relates to the technical field of rigid matrix slope regreening, and more specifically to the technical field of intelligent response carrier modified hydrogel solidified soil and preparation method thereof. Background Art

[0002] Slope greening can effectively protect exposed slopes and is conducive to the growth of ecological vegetation. It is currently widely used. Traditional slope greening technology usually uses cement-based ecological solidified soil, which has good economic performance and can adjust its setting time by introducing a curing agent. However, it also has some disadvantages, such as high alkalinity, which is not suitable for the growth of most plants. In the later stage, repeated alkalinity reduction is required to ensure its vegetation performance. The emergence of hydrogel system solidified soil has changed the disadvantage of high alkalinity of traditional cement-based solidified soil and has gradually received attention, but there are also problems such as fluidity retention performance and durability.

[0003] In some high slope greening projects, the construction method of spraying solidified soil is generally adopted. In the spraying stage, the solidified soil needs to have good rheological behavior, which is conducive to high-angle spraying behavior. After contacting the slope protection, the solidified soil needs to have good cohesion and quickly solidify to form a cementitious network to meet the slope protection strength requirements. The time window between the plastic stage and the solidification stage is quickly transformed, and the requirements for the ecological solidified soil mix ratio and manual operation are relatively high. Traditional ecological solidified soil often has the following defects on high slopes:

[0004] 1) It cures quickly, but its fluidity is poor, which affects the spraying operation.

[0005] 2) Or the fluidity is good, but the curing speed is slow, which affects the strength development. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problem of mismatch between fluidity maintenance and curing rate of hydrogel solidified bodies, and to provide a smart response carrier modified hydrogel solidified soil and a preparation method thereof.

[0007] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0008] The present invention provides a smart response carrier modified hydrogel solidified soil, which comprises the following components in parts by mass:

[0009] 400-500 parts of soil;

[0010] TMEDA 1.5-3.3 parts;

[0011] 25-50 parts of APS solution;

[0012] PVA 2-4.2 parts;

[0013] AAm 6 to 11 parts;

[0014] BiS 0.05-0.13 parts;

[0015] 160-200 parts of water;

[0016] 5-10 parts of solid paraffin;

[0017] 15-30 parts of porous ceramsite;

[0018] 5 to 10 parts of standard sand;

[0019] 1 to 3 parts of nano silicon dioxide.

[0020] In one embodiment, TMEDA is tetramethylethylenediamine with a molecular weight of 116.21 and a purity of 99.0%.

[0021] In one embodiment, the APS solution is a 40 wt % ammonium persulfate solution.

[0022] In one embodiment, the PVA is polyvinyl alcohol 1795 type, and the alcoholysis degree is 92% to 94%.

[0023] In one embodiment, AAm is acrylamide, and the purity is not less than 99.0%.

[0024] In one embodiment, BiS is methylenebisacrylamide with a purity of not less than 99.0%.

[0025] In one embodiment, the solid paraffin wax is sliced ​​paraffin wax with a melting point of 48-50°C.

[0026] In one embodiment, the porous ceramsite particle size is 6-10 mm, and the average micropore size is 200 microns;

[0027] Standard sand is ordinary construction sand with an average particle size of 0.3mm;

[0028] The particle size of nano-silicon dioxide is 20 to 50 nm.

[0029] The second aspect of the present invention provides a method for preparing a smart response carrier modified hydrogel solidified soil, which is used to prepare the above-mentioned smart response carrier modified hydrogel solidified soil, comprising the following steps:

[0030] S1. Preparation of mixed solution A:

[0031] PVA powder was mixed with water according to parts by mass to obtain a PVA aqueous solution; then, AAm, BIS and TMEDA were added to the PVA aqueous solution to obtain a mixed solution A.

[0032] S2. Preparation of intelligent response carrier:

[0033] S21. Loading APS into porous ceramsite:

[0034] According to the mass fraction, the porous ceramsite is immersed in the APS solution and vacuum treated for 12 hours. The negative pressure condition of the vacuum treatment is less than 20KPa, so that the porous ceramsite is fully loaded with the APS solution to obtain A-porous ceramsite;

[0035] S22, Encapsulation A-Porous ceramsite:

[0036] The solid paraffin is heated to a temperature T in a water-proof manner, sand particles and nano-silicon dioxide are added thereto, and the mixture is stirred evenly to obtain a packaging material. Subsequently, the A-porous ceramsite is rolled and shaped in the packaging material so that the surface of the porous ceramsite is evenly coated with the packaging material, and the mixture is cooled to room temperature to obtain a smart response carrier.

[0037] S3. Preparation of solidified soil:

[0038] The soil, the mixed solution A and the smart response carrier are stirred evenly to obtain the smart response carrier modified hydrogel solidified soil.

[0039] In one embodiment, the temperature T is 55-60°C.

[0040] The inventive principle of the present invention is as follows: the hydrogel component A is loaded into the porous ceramsite by vacuum treatment, and the porous ceramsite is encapsulated with an organic phase change material to prevent outflow. The organic phase change material is mixed with sand and silica, which will be destroyed under the action of force and heat to achieve a shell-breaking effect. The response carrier and the remaining hydrogel component B are added to the soil and stirred evenly, and then sprayed onto the slope matrix. When part of the response carrier is broken by external force, the encapsulated hydrogel component A is released. The two components contact and initiate rapid polymerization of the hydrogel, which will release a large amount of heat, continue to promote the release of the remaining response carrier, and accelerate curing.

[0041] The beneficial effects of the present invention are as follows:

[0042] 1. Compared with the prior art, the raw materials of the smart response carrier of the present invention are widely available, can exist stably in the natural environment, and have a strong ability to load hydrogel components, and can be widely used in the loading of various water-soluble solutions.

[0043] 2. The response carrier prepared by the preparation method of the present invention can trigger a response according to changes in the external environment to actively release the hydrogel crosslinker component, thereby transforming the hydrogel that originally polymerizes quickly and has weak controllability into an ecological soil curing agent with strong controllability and wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 Schematic diagram of the response carrier prepared in the present invention.

[0046] Figure 2 This is a diagram of a response carrier sample prepared according to the present invention.

[0047] Figure 3 This is the force crushing diagram of the response carrier prepared by the present invention. DETAILED DESCRIPTION

[0048] In order to make the technical problems, technical solutions and technical effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Example 1

[0051] A smart response carrier modified hydrogel solidified soil, comprising the following components in parts by mass:

[0052] Soil 500 parts;

[0053] TMEDA 0.5 parts;

[0054] 25 parts of APS solution;

[0055] PVA 2 parts;

[0056] AAm 6 parts;

[0057] BiS 0.05 parts;

[0058] 200 parts water;

[0059] 5 parts of solid paraffin;

[0060] 30 parts of porous ceramsite;

[0061] 5 parts of standard sand;

[0062] 1 part of nano silicon dioxide;

[0063] Specifically: TMEDA is tetramethylethylenediamine, with a molecular weight of 116.21 and a purity of 99.0%;

[0064] The APS solution is a 40 wt% ammonium persulfate solution;

[0065] PVA is polyvinyl alcohol 1795 type, with alcoholysis degree of 92%;

[0066] AAm is acrylamide with a purity of 99.0%.

[0067] BiS is methylenebisacrylamide with a purity of 99.0%.

[0068] The solid paraffin is sliced ​​paraffin with a melting point of 50°C.

[0069] The porous ceramsite particle size is 6 mm, and the average micropore size is 200 microns;

[0070] Standard sand is ordinary construction sand with an average particle size of 0.3mm;

[0071] The particle size of nano-silica is 30nm.

[0072] The preparation method of the intelligent response carrier modified hydrogel solidified soil comprises the following steps:

[0073] S1. Preparation of mixed solution A:

[0074] PVA powder and water are mixed according to parts by mass to obtain a PVA aqueous solution; then, AAm, BIS and TMEDA are added to the PVA aqueous solution to obtain a mixed solution A;

[0075] S2. Preparation of intelligent response carrier:

[0076] (1) Loading APS into porous ceramsite:

[0077] According to the mass fraction, the porous ceramsite is immersed in the APS solution and vacuum treated for 12 hours. The negative pressure condition of the vacuum treatment is less than 20KPa, so that the porous ceramsite is fully loaded with the APS solution to obtain A-porous ceramsite;

[0078] (2) Encapsulation A-porous ceramsite:

[0079] The solid paraffin is heated to a temperature of 55°C in a water bath, sand particles and nano-silicon dioxide are added thereto, and the mixture is stirred evenly to obtain a packaging material, and then the A-porous ceramsite is rolled and shaped in the packaging material so that the surface of the porous ceramsite is evenly coated with the packaging material, and the mixture is cooled to room temperature to obtain a smart response carrier;

[0080] S3. Preparation of solidified soil:

[0081] The soil, the mixed solution A and the smart response carrier are stirred evenly to obtain the smart response carrier modified hydrogel solidified soil.

[0082] Example 2

[0083] A smart response carrier modified hydrogel solidified soil, comprising the following components in parts by mass:

[0084] Soil 500 parts;

[0085] TMEDA 1 part;

[0086] 25 parts of APS solution;

[0087] PVA 4.2 parts;

[0088] AAm 11 copies;

[0089] BiS 0.13 parts;

[0090] 200 parts water;

[0091] 10 parts of solid paraffin;

[0092] 30 parts of porous ceramsite;

[0093] 5 parts of standard sand; and

[0094] 1 part of nano silicon dioxide.

[0095] Specifically, TMEDA is tetramethylethylenediamine, with a molecular weight of 116.21 and a purity of 99.0%;

[0096] The APS solution is a 40 wt% ammonium persulfate solution;

[0097] PVA is polyvinyl alcohol 1795 type, with alcoholysis degree of 92%;

[0098] AAm is acrylamide with a purity of 99.0%.

[0099] BiS is methylenebisacrylamide with a purity of 99.0%.

[0100] The solid paraffin is sliced ​​paraffin with a melting point of 50°C.

[0101] The porous ceramsite particle size is 6 mm, and the average micropore size is 200 microns;

[0102] Standard sand is ordinary construction sand with an average particle size of 0.3mm;

[0103] The particle size of nano-silica is 30nm.

[0104] The preparation method of the intelligent response carrier modified hydrogel solidified soil comprises the following steps:

[0105] S1. Preparation of mixed solution A:

[0106] PVA powder and water are mixed according to parts by mass to obtain a PVA aqueous solution; then, AAm, BIS and TMEDA are added to the PVA aqueous solution to obtain a mixed solution A;

[0107] S2. Preparation of intelligent response carrier:

[0108] S21. Loading APS into porous ceramsite:

[0109] According to the mass fraction, the porous ceramsite is immersed in the APS solution and vacuum treated for 12 hours. The negative pressure condition of the vacuum treatment is less than 20KPa, so that the porous ceramsite is fully loaded with the APS solution to obtain A-porous ceramsite;

[0110] S22, Encapsulation A-Porous ceramsite:

[0111] The solid paraffin is heated to a temperature of 55°C in a water-proof manner, sand particles and nano-silicon dioxide are added thereto, and the mixture is stirred evenly to obtain a packaging material. Subsequently, the A-porous ceramsite is rolled and shaped in the packaging material so that the surface of the porous ceramsite is evenly coated with the packaging material, and the mixture is cooled to room temperature to obtain a smart response carrier.

[0112] S3. Preparation of solidified soil:

[0113] The soil, the mixed solution A and the smart response carrier are stirred evenly to obtain the smart response carrier modified hydrogel solidified soil.

[0114] Comparative Example 1

[0115] The difference between Comparative Example 1 and Example 1 is that all the raw materials are uniformly mixed together.

[0116] The strength and fluidity tests were performed on Examples 1-2 and Comparative Example 1.

[0117] In terms of strength test, the two groups of solidified soils prepared in Example 1 and Example 2 after curing for 60 minutes were subjected to slope simulation spraying, with an initial spraying velocity of 30m / s, a contact substrate material of concrete, a slope of 60°, and normal temperature and humidity maintenance. The slopes 3d and 7d after spraying were cut and sampled, and unconfined compression tests were performed. The performance of the samples was tested with reference to GB / T 50123-2019 "Technical Specifications for Solidified Soil" and ASTM D1633 "Unconfined Compressive Strength Test Methods". The comparative example could not be sprayed, and was directly formed in the mold and cured to the corresponding age test. In terms of fluidity. The expansion degree is used to reflect the fluidity of the fluidized solidified soil. The determination method is: a cylinder with openings on both the top and bottom, a diameter and a height of 8cm, is used to pour the fluidized solidified soil, and after tamping, it is smoothed, and then the cylinder is lifted. The fluidized solidified soil produces a collapse phenomenon, and the minimum diameter and maximum diameter of the collapsed body are measured. The arithmetic average of the two is the expansion degree.

[0118] The test results are shown in Table 1.

[0119] Table 1 Test results of Example 1, Example 2 and Comparative Example 1

[0120]

[0121] By comparing the test results of Example 1 and Example 2 with the comparative example 1, it can be seen that the intelligent response carrier modified hydrogel solidified soil of the present invention effectively improves the fluidity and flow retention performance of the solidified soil, and the solidification strength does not decrease after spraying, and is even improved compared with the comparative example.

Claims

1. A smart response carrier modified hydrogel solidified soil, characterized in that: In parts by mass, it includes the following components: 400-500 parts of soil; TMEDA 1.5-3.3 parts; 25-50 parts of APS solution; PVA 2-4.2 parts; AAm 6 to 11 parts; BiS 0.05-0.13 parts; 160-200 parts of water; 5-10 parts of solid paraffin; 15-30 parts of porous ceramsite; 5 to 10 parts of standard sand; and 1 to 3 parts of nano silicon dioxide.

2. The intelligent response carrier modified hydrogel solidified soil according to claim 1, characterized in that: The TMEDA is tetramethylethylenediamine, with a molecular weight of 116.21 and a purity of 99.0%.

3. The intelligent response carrier modified hydrogel solidified soil according to claim 1, characterized in that: The APS solution is a 40 wt % ammonium persulfate solution.

4. The intelligent response carrier modified hydrogel solidified soil according to claim 1, characterized in that: The PVA is polyvinyl alcohol 1795 type, and the alcoholysis degree is 92% to 94%.

5. The intelligent response carrier modified hydrogel solidified soil according to claim 1, characterized in that: The AAm is acrylamide, and the purity is not less than 99.0%.

6. The intelligent response carrier modified hydrogel solidified soil according to claim 1, characterized in that: The BiS is methylenebisacrylamide, and the purity is not less than 99.0%.

7. The intelligent response carrier modified hydrogel solidified soil according to claim 1, characterized in that: The solid paraffin is sliced ​​paraffin with a melting point of 48-50°C.

8. The intelligent response carrier modified hydrogel solidified soil according to claim 1, characterized in that: The porous ceramsite particle size is 6-10 mm, and the average micropore size is 200 microns; The standard sand is ordinary building sand with an average particle size of 0.3 mm; The particle size of the nano silicon dioxide is 20 to 50 nm.

9. A method for preparing a smart response carrier modified hydrogel solidified soil, for preparing a smart response carrier modified hydrogel solidified soil according to any one of claims 1 to 8, comprising the following steps: S1. Preparation of mixed solution A: PVA powder and water are mixed according to parts by mass to obtain a PVA aqueous solution; then, AAm, BIS and TMEDA are added to the PVA aqueous solution to obtain a mixed solution A; S2. Preparation of intelligent response carrier: S21. Loading APS into porous ceramsite: According to the mass fraction, the porous ceramsite is immersed in the APS solution and vacuum treated for 12 hours. The negative pressure condition of the vacuum treatment is less than 20KPa, so that the porous ceramsite is fully loaded with the APS solution to obtain A-porous ceramsite; S22, Encapsulation A-Porous ceramsite: The solid paraffin is heated to a temperature T in a water-proof manner, sand particles and nano-silicon dioxide are added thereto, and the mixture is stirred evenly to obtain a packaging material. Subsequently, the A-porous ceramsite is rolled and shaped in the packaging material so that the surface of the porous ceramsite is evenly coated with the packaging material, and the mixture is cooled to room temperature to obtain a smart response carrier. S3. Preparation of solidified soil: The soil, the mixed solution A and the smart response carrier are stirred evenly to obtain the smart response carrier modified hydrogel solidified soil.

10. The method for preparing a smart response carrier modified hydrogel solidified soil according to claim 9, characterized in that: In step S22, the temperature T is 55-60°C.

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