Multi-layer flexible mucky soil matrix regenerated composite board as well as preparation method and application thereof

Abstract

The invention relates to the field of muck resource utilization, in particular to a multi-layer flexible mucky soil-based regenerated composite board and a preparation method and application thereof.The preparation method includes the steps that S1, polyethylene film blocks and a mucky soil solidified premix containing polyethylene fibers and mucky soil particles are prepared; s2, a layer of polyethylene film block is placed in the mold, then a layer of glue is brushed on the polyethylene film block, then a layer of mucky soil solidification premixed material is laid to form a premixed material layer, a layer of glue continues to be brushed on the premixed material layer, the operation is repeated in the mold to form prefabricated multi-layer composite boards which are alternately arranged from bottom to top, and the prefabricated multi-layer composite boards are formed; the uppermost layer and the lowermost layer of the prefabricated multi-layer composite board are both polyethylene film blocks; s3, repeatedly performing needling operation on the prefabricated multi-layer composite board, and then leveling to form a multi-layer composite board with fibers entangled layer by layer; and S4, the multi-layer composite board is cured, and hot pressing is conducted after curing is completed. Compared with the prior art, the application range of the sludge is enriched.

Description

Technical Field

[0001] The invention relates to the field of slag resource utilization, and in particular to a multi-layer flexible silty soil-based recycled composite board and a preparation method and application thereof. Background Art

[0002] The large-scale development of water conservancy and water environment management, as well as urban construction projects in my country, such as reclamation projects, port projects, river and lake dredging projects, etc., has produced a large amount of high-water content silt that is in urgent need of treatment and disposal. Usually, this type of silt has a high water content, high clay content, and extremely low strength. Many of them are also rich in organic matter and pollutants. It is a special kind of soil that is difficult to use directly in engineering. The conventional disposal method is to fill it up nearby or dump it into the sea as waste. If it is not properly handled, it will occupy a large amount of land resources for a long time and cause pollution and harm to the surrounding environment. How to make resource utilization of such abandoned high-water content silt is an important issue.

[0003] The current application of silt is mainly to process it into solidified soil for resource utilization. For example, CN118005354A discloses a fluidized solidified soil based on high-water content silty clay and a preparation method thereof, wherein cement, quicklime, gypsum, slag and fly ash are fully mixed to obtain component A; polypropylene and a high molecular weight water-absorbing resin are fully mixed to obtain component B; component A, the component B and the water glass are sequentially added to the high-water content silty clay, mixed into a slurry, and a fluidized solidified soil is formed.

[0004] The above-mentioned fluidized solidified soil is prepared by combining high-water content silty clay with cement, quicklime and other components to make resource utilization of silt.

[0005] There is an urgent need to develop a new resource utilization of silt to enrich the application scope of silt. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a multi-layer flexible silt-based recycled composite board and a preparation method and application thereof, so as to solve the problem in the prior art that there is an urgent need to develop a new resource utilization of silt to enrich the application scope of silt.

[0007] To achieve the above object, the first aspect of the present invention adopts the following technical solution: a method for preparing a multi-layer flexible silt-based recycled composite board, comprising the following steps: Step S1, preparing polyethylene film blocks and a silty soil solidification premix containing polyethylene fibers and silty soil particles; Step S2, placing a layer of polyethylene film blocks in the mold, then applying a layer of glue on the polyethylene film blocks, then spreading a layer of silt soil solidified premix to form a premix layer, continuing to apply a layer of glue on the premix layer, repeating the operation in the mold to form a prefabricated multi-layer composite board having polyethylene film blocks and premix layers arranged alternately from bottom to top, wherein the uppermost layer and the lowermost layer in the prefabricated multi-layer composite board are both polyethylene film blocks; Step S3, repeatedly performing a needle punching operation on the prefabricated multi-layer composite board and then flattening it to form a multi-layer composite board with fiber interlacing and entanglement; Step S4, curing the multilayer composite board, and hot pressing after curing to complete the preparation.

[0008] Preferably, the silty soil solidification premix also includes cement, mineral powder, fly ash, sodium silicate and water, and calculated by weight, the silty soil particles, cement, mineral powder, fly ash, sodium silicate, polyethylene fiber and water correspond to 100 parts, 8-12 parts, 23-27 parts, 13-17 parts, 1.8-2.2 parts, 2.0-2.4 parts and 68-72 parts respectively.

[0009] Preferably, the silt soil particles are obtained by drying the silt soil in a vacuum oven and then crushing the silt soil into particles with a particle size of less than 1 mm.

[0010] Preferably, the modulus of the sodium silicate is 1.5.

[0011] Preferably, the length of the polyethylene fiber is 6-8 mm.

[0012] Preferably, the polyethylene film block has a thickness of 0.2 mm, and the premix layer has a thickness of 1 mm.

[0013] Preferably, the step S3 specifically comprises: The prefabricated multi-layer composite board is cross-needled repeatedly by using a needle with hooks and needles in a combination of forward needling and needling at a 45° angle, and the needles are inserted and pulled out once at an average interval of 1 mm. After the needle punching is completed, the prefabricated multi-layer composite board is leveled to form a multi-layer composite board with fiber interlacing and entanglement.

[0014] Preferably, the step S4 specifically comprises: The multi-layer composite board is placed in a standard curing room with a temperature of 20°C and a humidity of 95% for curing, and is air-dried after curing; Then, the multilayer composite board was placed in a hot press at a temperature of 150° C. and hot pressed at a pressure of 100 kPa for 3 minutes.

[0015] The second aspect of the present invention adopts the following technical solution: a multi-layer flexible silt-based recycled composite board is prepared by the preparation method of the multi-layer flexible silt-based recycled composite board described in the first aspect of the present invention.

[0016] The third aspect of the present invention adopts the following technical solution: an application of applying the multi-layer flexible silt-based recycled composite board described in the second aspect of the present invention to the field of architectural decoration.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts soft polyethylene film blocks and hard silt soil solidification premix to be alternately stacked to form a multi-layer structure of alternating soft and hard, so as to improve the flexibility of the silt soil solidification premix containing silt soil particles; glue is used at the same time to improve the interface strength of organic and inorganic layers; and acupuncture is performed to make the polyethylene fibers in the silt soil solidification premix penetrate the entire multi-layer composite board, and then hot pressing is performed to melt and connect the polyethylene fibers and the polyethylene film, and the multi-layer composite board is sealed inside and on the surface to form a flexible silt soil-based recycled composite board with a three-dimensional fiber network and a multi-layer structure, which improves the tensile strength and bending performance of the silt soil solidification premix, has an extremely low water absorption rate, can be used in the field of building decoration, and improves the resource utilization rate of silt. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below through specific embodiments: Example 1 Step S1, the silty soil is placed in a vacuum oven at 110°C for 24 hours to dry, and then crushed into particles with a particle size of less than 1 mm. 100 parts of silty soil particles are weighed, and 10 parts of cement, 25 parts of mineral powder, 15 parts of fly ash, 2 parts of sodium silicate with a modulus of 1.5, 2.2 parts of polyethylene fiber (polyethylene fiber length is 6-8 mm) and 70 parts of water are added, and the mixture is placed in a mortar mixer and mixed evenly to form a silty soil solidification premix.

[0019] Step S2, cut a 0.2mm thick polyethylene film into 5 strips with a length and width of 200mm and 50mm respectively, first place a polyethylene film (named as layer B) in a mold with a length, width and thickness of 200mm, 50mm and 5mm respectively, then apply a layer of PVC glue on the polyethylene film, and then pour a 1mm thick silt soil solidification premix (named as layer A) on the glue, and then apply a layer of PVC glue on it after leveling, and then lay a polyethylene film, and then apply a layer of PVC glue on it, and then pour a 1mm thick silt soil solidification premix, and repeat this process until the top layer is a polyethylene film for sealing, thereby forming a prefabricated multi-layer composite panel with a total of 9 layers and a thickness of 5mm, and the prefabricated multi-layer composite panel is arranged from bottom to top in a BABABABAB manner.

[0020] Step S3, repeatedly needle-punching the prefabricated multi-layer composite board with a barbed needle, and each time, the prefabricated multi-layer composite board is first needle-punched in a normal direction from the top to the bottom, and then needle-punched at an angle of 45° to the right, and then needle-punched at an angle of 45° to the left, and the cross-puncturing is repeatedly performed in the above manner, and the needle-punching is performed once on the prefabricated multi-layer composite board at an average interval of 1 mm, so that the polyethylene fibers in the silty soil solidification premix are brought into the entire prefabricated multi-layer composite board by the barbs on the needle, and then leveled to form a multi-layer composite board with fiber interlayer entanglement.

[0021] Step S4, placing the multi-layer composite board in a standard curing room (the standard curing room has a constant temperature of 20°C and a humidity of 95%), curing for 28 days and then drying; then placing the multi-layer composite board in a 150°C hot press, hot pressing with a pressure of 100 kPa for 3 minutes, melting and connecting the polyethylene fiber and the polyethylene film, and achieving surface sealing, and finally forming a multi-layer flexible silt-based recycled composite board.

[0022] The obtained flexible silt-based recycled composite board was tested with reference to GB / T 1040.1-2018, and the tensile strength was found to be 8.86 MPa; the water absorption was found to be 0.02% with reference to GB / T 50081-2019; the curvature was found to be 360° using the following self-test method.

[0023] Among them, the self-detection method is specifically: one end of the flexible silt soil-based regenerated composite board is vertically fixed on a horizontal plane. At this time, the flexible silt soil-based regenerated composite board has a fixed end and a movable end, and then the movable end is bent around the fixed end. When the limit bending is reached, the angle between the plane where the movable end is located and the plane where the fixed end is located is the curvature.

[0024] Example 2 The only difference from Example 1 is: In step S1, 12 parts of cement, 27 parts of mineral powder, 17 parts of fly ash, 2.2 parts of sodium silicate, 2.4 parts of polyethylene fiber and 72 parts of water are added.

[0025] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 8.98 MPa, a water absorption rate of 0.02%, and a curvature of 360°.

[0026] Example 3 The only difference from Example 1 is: In step S1, 8 parts of cement, 23 parts of mineral powder, 13 parts of fly ash, 1.8 parts of sodium silicate, 2.0 parts of polyethylene fiber and 68 parts of water were added.

[0027] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 8.78 MPa, a water absorption rate of 0.02%, and a curvature of 360°.

[0028] Example 4 The only difference from Example 1 is: In step S2, only the total number of layers is changed, and the total number of layers is 7, so the thickness of layer A is adjusted to 1.4 mm.

[0029] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 6.23 MPa, a water absorption rate of 0.02%, and a curvature of 170°.

[0030] Example 5 The only difference from Example 1 is: In step S2, only the total number of layers is changed, and the total number of layers is 5, so the thickness of layer A is adjusted to 2.2 mm.

[0031] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 4.17 MPa, a water absorption rate of 0.02%, and a curvature of 85°.

[0032] Example 6 The only difference from Example 1 is: In step S2, only the total number of layers is changed, and the total number of layers is 3, so the thickness of layer A is adjusted to 4.6 mm.

[0033] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 2.87 MPa, a water absorption rate of 0.02%, and a curvature of 46°.

[0034] Comparative Example 1 Place the muddy soil in a vacuum oven at 110°C for 24 hours, and then crush it into particles with a particle size of less than 1mm. Weigh 100kg of muddy soil particles, add 10kg of cement, 25kg of mineral powder, 15kg of fly ash, 2kg of sodium silicate with a modulus of 1.5, 2.2kg of polyethylene fiber (fiber length is 6-8mm) and 70kg of water, put it in a mortar mixer and mix it evenly, then pour it into a mold with a length, width and thickness of 200mm, 50mm and 5mm, and the pouring thickness in the mold is 5mm. After curing at room temperature for 24 hours, demould it, and put it in a standard curing room (constant temperature of 20°C and humidity of 95%) for 28 days to form it.

[0035] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 1.42 MPa, a water absorption rate of 14.8%, and a curvature of 32°.

[0036] Comparative Example 2 Place the muddy soil in a vacuum oven at 110°C for 24 hours, and then crush it into particles with a particle size of less than 1mm. Weigh 100kg of muddy soil particles, add 10kg of cement, 25kg of mineral powder, 15kg of fly ash, 2kg of sodium silicate with a modulus of 1.5, 2.2kg of polyethylene fiber (fiber length is 6-8mm) and 70kg of water, put them in a mortar mixer and mix them evenly, then pour them into a mold with a length, width and thickness of 200mm, 50mm and 5mm, and the pouring thickness in the mold is 5mm.

[0037] After pouring into the mold, the prefabricated multi-layer composite board is repeatedly needled using the needle method in Example 1 (a needle with hooks is used to repeatedly needle-punch the prefabricated multi-layer composite board, and each time it is first needle-punched from the top of the prefabricated multi-layer composite board to the bottom thereof, and then it is needle-punched at an angle of 45° to the right, and then it is needle-punched at an angle of 45° to the left, and the cross-puncture is repeated in the above manner, and the insertion and pulling are performed once at an average interval of 1 mm on the prefabricated multi-layer composite board), and then leveled, cured at room temperature for 24 hours, demolded, and placed in a standard curing room (constant temperature 20°C and humidity 95%) for 28 days to form.

[0038] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 1.58 MPa, a water absorption rate of 14.6%, and a curvature of 35°.

[0039] Comparative Example 3 The only difference from Example 1 is: In step S2, placing a polyethylene film and applying PVC glue in the mold are eliminated.

[0040] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 1.86 MPa, a water absorption rate of 12.3%, and a curvature of 38°.

[0041] Comparative Example 4 The only difference from Example 1 is: In step S4, after curing for 28 days, the product is air-dried and directly molded without hot pressing.

[0042] The test results show that: The obtained flexible silt soil-based recycled composite board has a tensile strength of 2.46 MPa, a water absorption rate of 8.65%, and a curvature of 76°.

[0043] The flexible silty soil-based recycled composite boards obtained in Examples 1 to 6 improve the tensile strength and bending properties of the silty soil after solidification, and have extremely low water absorption, and can be used in the field of building decoration.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a multi-layer flexible silt-based recycled composite board, characterized in that: The following steps are involved: Step S1, preparing polyethylene film blocks and a silty soil solidification premix containing polyethylene fibers and silty soil particles; Step S2, placing a layer of polyethylene film blocks in the mold, then applying a layer of glue on the polyethylene film blocks, then spreading a layer of silt soil solidified premix to form a premix layer, continuing to apply a layer of glue on the premix layer, repeating the operation in the mold to form a prefabricated multi-layer composite board having polyethylene film blocks and premix layers arranged alternately from bottom to top, wherein the uppermost layer and the lowermost layer in the prefabricated multi-layer composite board are both polyethylene film blocks; Step S3, repeatedly performing a needle punching operation on the prefabricated multi-layer composite board and then flattening it to form a multi-layer composite board with fiber interlacing and entanglement; Step S4, curing the multilayer composite board, and hot pressing after curing to complete the preparation.

2. The method for preparing a multi-layer flexible silt-based recycled composite board according to claim 1, characterized in that: The silty soil solidification premix also includes cement, mineral powder, fly ash, sodium silicate and water, and calculated by weight, the silty soil particles, cement, mineral powder, fly ash, sodium silicate, polyethylene fiber and water correspond to 100 parts, 8-12 parts, 23-27 parts, 13-17 parts, 1.8-2.2 parts, 2.0-2.4 parts and 68-72 parts respectively.

3. The method for preparing a multi-layer flexible silt-based recycled composite board according to claim 1 or 2, characterized in that: The silt soil particles are obtained by drying the silt soil in a vacuum oven and then crushing it into particles with a particle size less than 1 mm.

4. The method for preparing a multi-layer flexible muddy soil-based recycled composite board according to claim 2, characterized in that: The modulus of the sodium silicate is 1.

5.

5. The method for preparing a multi-layer flexible silt-based recycled composite board according to claim 1 or 2, characterized in that: The length of the polyethylene fiber is 6-8 mm.

6. The method for preparing a multi-layer flexible silt-based recycled composite board according to claim 1, characterized in that: The polyethylene film block has a thickness of 0.2 mm, and the premixed material layer has a thickness of 1 mm.

7. The method for preparing a multi-layer flexible muddy soil-based recycled composite board according to claim 1, characterized in that: The step S3 specifically comprises: The prefabricated multi-layer composite board is cross-needled repeatedly by using a needle with hooks and needles in a combination of forward needling and needling at a 45° angle, and the needles are inserted and pulled out once at an average interval of 1 mm. After the needle punching is completed, the prefabricated multi-layer composite board is leveled to form a multi-layer composite board with fiber interlacing and entanglement.

8. The method for preparing a multi-layer flexible silt-based recycled composite board according to claim 1, characterized in that: The step S4 specifically comprises: The multi-layer composite board is placed in a standard curing room with a temperature of 20°C and a humidity of 95% for curing, and is air-dried after curing; Then, the multilayer composite board was placed in a hot press at a temperature of 150° C. and hot pressed at a pressure of 100 kPa for 3 minutes.

9. A multi-layer flexible silt-based recycled composite board, characterized in that: The composite board is prepared by the method for preparing a multi-layer flexible muddy soil-based recycled composite board according to any one of claims 1 to 8.

10. An application, characterized in that: The multi-layer flexible silt-based recycled composite board described in claim 9 is applied in the field of architectural decoration.