Fiber-improved anti-cracking fluid-state solidified soil and preparation method thereof

Abstract

The invention provides fiber-improved anti-crack flow state solidified soil and a preparation method thereof, and belongs to the technical field of engineering materials, and the fiber-improved anti-crack flow state solidified soil comprises water and powder; the water-solid ratio of the water to the powder is 0.4-0.6; the powder material is prepared from the following raw materials in parts by mass: 84 to 85 parts of constructional engineering soil, 0.1 to 1 part of polyacrylamide modified aluminum silicate fiber and 10 to 20 parts of soil curing agent. The problems that in the prior art, traditional flow-state solidified soil is poor in toughness, so that the crack resistance and ductility are poor, and the water stability and the anti-scouring performance are low can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering materials, and more particularly to a fiber-modified anti-cracking fluidized solidified soil and a preparation method thereof. BACKGROUND

[0002] The continuous urbanization drives the expansion of construction scale, and the construction of infrastructure and urban development generates a large amount of construction waste, mainly including dredged sludge, foundation pit slurry and shield spoil, etc. The current treatment method mainly relies on on-site landfill or external transportation, which causes waste of land resources and potential pollution of the ecological environment, especially in terms of soil and water.

[0003] Such construction waste mainly comes from engineering links such as foundation pit excavation, underground continuous wall, pile foundation construction and grouting reinforcement, and has physical properties of high water content clay or silty clay, often mixed with concrete blocks and formwork and other construction waste, which makes it not suitable for direct backfilling. In the case of limited space, complex structure or high quality requirements for backfilling, such as pipe gallery, pipe trench, house core and fertilizer trench, etc., the traditional backfilling process has obvious limitations in terms of density, construction efficiency and safety.

[0004] In order to improve the recycling performance of construction waste, solidification technology has attracted widespread attention. By adding inorganic cementing materials such as cement, fly ash and slag, cementation reaction of soil body is promoted, thereby improving its stability, strength and durability. The fluidized solidified soil developed based on this technology has good fluidity, self-compacting property and pumpability, and has superior construction adaptability in foundation pit backfilling, underground cavity filling and foundation improvement, etc., and has become an important means for the resource treatment of construction waste. However, the traditional fluidized solidified soil has poor toughness, which leads to poor crack resistance and ductility, and low water stability and erosion resistance. SUMMARY

[0005] In view of the above problems, the purpose of the present application is to provide a fiber-modified anti-cracking fluidized solidified soil and a preparation method thereof, so as to solve the problem of poor toughness of the traditional fluidized solidified soil in the prior art, which leads to poor crack resistance and ductility, and low water stability and erosion resistance.

[0006] In one aspect, the present application provides a fiber-modified anti-cracking fluidized solidified soil, comprising water and powder; wherein,

[0007] The water-solid ratio of the water to the powder is 0.4-0.6;

[0008] The powder comprises the following raw materials in mass fraction:

[0009] 84-85 parts of construction engineering soil, 0.1-1 part of polyacrylamide modified aluminum silicate fiber, and 10-20 parts of soil solidifying agent.

[0010] In addition, preferably, the construction engineering soil is a mixture of construction waste fine powder and engineering slurry mixed in any proportion.

[0011] In addition, preferably, the particle size of the construction waste fine powder is 5-9.5 mm.

[0012] In addition, preferably, the engineering slurry is waste slurry generated during construction engineering construction or slurry prepared by stirring discarded soil with water.

[0013] In addition, preferably, the preparation method of the polyacrylamide modified aluminum silicate fiber comprises the following steps:

[0014] The aluminum silicate fiber is dissolved in water to obtain an aluminum silicate fiber aqueous solution; wherein the mass ratio of the aluminum silicate fiber to the water is 1:0.2-0.3;

[0015] Polyacrylamide is added to the aluminum silicate fiber aqueous solution, and the aluminum silicate fiber aqueous solution and the polyacrylamide are allowed to react at room temperature for 1-2 h to obtain polyacrylamide modified aluminum silicate fiber; wherein the mass ratio of the aluminum silicate fiber to the polyacrylamide is 40-60:1.

[0016] In addition, preferably, the molecular weight of the polyacrylamide is 5-10 million.

[0017] In addition, preferably, the soil body curing agent is compounded from cement and fly ash in a mass ratio of 1:0.5-1.

[0018] In addition, preferably, the cement is Portland cement.

[0019] In addition, preferably, the fly ash is fly ash with a SiO2 content of less than 40%.

[0020] On the other hand, the present application provides a preparation method of the fiber improved anti-cracking fluidized cured soil as described above, comprising the following steps:

[0021] The construction engineering soil and the water are mixed to form a slurry slurry;

[0022] The polyacrylamide modified aluminum silicate fiber and the soil body curing agent are added to the slurry slurry and uniformly mixed to obtain the fiber improved anti-cracking fluidized cured soil.

[0023] From the above technical solution can be known, the fiber improvement anti-cracking fluidized solidified soil and preparation method thereof provided by the application, by taking the construction engineering soil and the polyacrylamide modified aluminum silicate fiber and the soil solidifying agent as the powder, the performance of the fluidized solidified soil is enhanced by the fiber, which is mainly due to the reinforcement and bridging effect of the polyacrylamide modified aluminum silicate fiber in the microstructure; after the surface modification of the aluminum silicate fiber by the polyacrylamide, the aluminum silicate fiber has excellent properties such as easy dispersion, high strength, corrosion resistance and high temperature resistance, and can improve the compressive strength and crack resistance of the fluidized solidified soil as a reinforcing material; the polyacrylamide modified aluminum silicate fiber forms a uniform three-dimensional network structure in the soil of the construction engineering soil, which can effectively hinder the initiation and expansion of microcracks, improve the original brittle failure mode of the solidified soil, and improve the crack resistance and ductility of the soil; the polyacrylamide modified aluminum silicate fiber enhances the cohesion and stress transfer capacity of the soil through physical entanglement and interfacial friction, thereby improving the bending, compressive and shear strengths, and when subjected to load or dry-wet cycle environment, the fiber can disperse stress concentration and relieve the problem of structural instability caused by volume change, thereby significantly improving the volume stability and durability; in addition, the polyacrylamide modified aluminum silicate fiber can inhibit the expansion of pore water channels and reduce the erosion rate, thereby enhancing the water stability of the soil.

[0024] In summary, the application has the following advantages:

[0025] 1. The polyacrylamide modified aluminum silicate fiber forms a network structure in the soil, effectively limits the initiation and expansion of cracks, improves the brittle cracking problem caused by dry shrinkage, temperature difference or load, and improves the structural integrity of the soil;

[0026] 2. The polyacrylamide modified aluminum silicate fiber can bear tensile stress when the soil is stressed, delay the failure process, and change the brittle failure mode of the material to a more ductile failure mode, thereby improving the overall deformation coordination of the soil;

[0027] 3. The polyacrylamide modified aluminum silicate fiber can block the damage of water flow to the structure, improve the pore connectivity, improve the stability of the material in the groundwater or rainfall environment, and prolong the service life;

[0028] 4. The polyacrylamide modified aluminum silicate fiber has a significant effect on structural ductility enhancement, and can improve the bending and shear performance, especially showing higher crack control ability in the initial stage of load;

[0029] 5. The polyacrylamide modified aluminum silicate fiber does not affect the fluidity of the soil, and gives the material higher structural toughness and filling reliability, and is suitable for more complex geological and construction environments, such as soft soil foundation or tunnel backfilling.

[0030] To achieve the foregoing and related ends, the one or more aspects of the present application, including the features recited in the following detailed description, are drawn to. The following description and the annexed drawings set forth in detail certain illustrative aspects of the application. These aspects are indicative, however, of but a few of the various ways in which the principles of the application can be employed. Other objects, advantages, and novel features of the application will become apparent from the following detailed description when considered in conjunction with the annexed drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] Other objects and advantages of the present application will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth, by way of illustration and example, certain embodiments of this application.

[0032] Figure 1 A flow chart of a method for preparing the fiber-modified anti-cracking fluidified solidified soil according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In the following description, for purposes of explanation and to provide a complete understanding of one or more embodiments, numerous specific details are set forth. It will be apparent, however, to one skilled in the art that these embodiments can be practiced without some or all of these specific details.

[0034] In view of the foregoing, the conventional fluidified solidified soil has poor toughness, resulting in poor anti-cracking performance and ductility, and low water stability and anti-scouring performance, in the prior art, the present application provides a fiber-modified anti-cracking fluidified solidified soil and a preparation method thereof.

[0035] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0036] To illustrate the fiber-modified anti-cracking fluidified solidified soil provided by the present application, Figure 1 A flow chart of a method for preparing the fiber-modified anti-cracking fluidified solidified soil according to an embodiment of the present application.

[0037] The fiber-modified anti-cracking fluidified solidified soil provided by the present application mainly comprises water and a powder; wherein,

[0038] The water-solid ratio of the water and the powder is 0.4-0.6;

[0039] The powder comprises the following raw materials in mass fraction:

[0040] 84-85 parts of construction engineering soil, 0.1-1 part of polyacrylamide modified aluminum silicate fiber, and 10-20 parts of soil solidifying agent.

[0041] By taking the construction engineering soil and the polyacrylamide modified aluminum silicate fiber and soil solidifying agent as a powder, the reinforcing effect of the fiber on the performance of the flow state solidified soil is fully utilized, which is mainly due to the reinforcing and bridging effect of the polyacrylamide modified aluminum silicate fiber in the microstructure. After the surface modification of the aluminum silicate fiber by polyacrylamide, the fiber has the advantages of easy dispersion, high strength, corrosion resistance, high temperature resistance and the like, and can improve the compressive strength and crack resistance of the flow state solidified soil as a reinforcing material. The polyacrylamide modified aluminum silicate fiber forms a uniform three-dimensional network structure in the soil of the construction engineering soil, which can effectively hinder the initiation and expansion of microcracks, improve the original brittle failure mode of the solidified soil, and improve the crack resistance and ductility of the soil. The polyacrylamide modified aluminum silicate fiber enhances the cohesion and stress transfer capacity of the soil through physical entanglement and interfacial friction, thereby improving the bending, compressive and shear strengths. When subjected to load or dry-wet cycle, the fiber can disperse stress concentration and relieve the instability problem caused by volume change, thereby significantly improving the volume stability and durability. In addition, the polyacrylamide modified aluminum silicate fiber can inhibit the expansion of pore water channels and reduce the erosion rate, thereby enhancing the water stability of the soil.

[0042] As a preferred scheme of the present application, the construction engineering soil is a mixture of construction waste fine powder and engineering slurry mixed in any proportion.

[0043] It should be noted that the definition, requirements and classification of the construction engineering soil in the present application comply with the definition, requirements and classification of the construction waste fine powder and the engineering slurry described in the local standard DB 31 / T1483-2024 "Construction Waste and Engineering Slurry Regeneration Self-compaction Filling Technical Specification".

[0044] As a preferred scheme of the present application, the particle size of the construction waste fine powder is 5mm-9.5mm.

[0045] Specifically, the construction waste fine powder is a mixture of waste brick particles, old mortar, broken ceramics, stone chips, powder, clay and other impurities produced after the construction waste is processed by crushing, sorting and screening processes. In a preferred scheme of the present application, the particle size of the construction waste fine powder is preferably but not limited to 5mm-9.5mm.

[0046] As a preferred scheme of the present application, the engineering slurry is waste slurry generated during the construction of building engineering or slurry prepared by stirring discarded soil with water.

[0047] Specifically, the engineering slurry can be waste slurry generated during the construction of any one of a bored pile foundation, an underground continuous wall, a slurry shield, a slurry pipe jacking, a horizontal directional drilling, or a slurry prepared by stirring discarded soil with water. When the slurry is prepared by stirring discarded soil with water, the ratio of discarded soil to water can be determined according to actual needs, which is not particularly limited in the present application.

[0048] As a preferred scheme of the present application, the preparation method of the polyacrylamide modified aluminum silicate fiber comprises the following steps:

[0049] The aluminum silicate fiber is dissolved in water to obtain an aluminum silicate fiber aqueous solution; wherein the mass ratio of the aluminum silicate fiber to water is 1:0.2-0.3;

[0050] Polyacrylamide is added to the aluminum silicate fiber aqueous solution, and the aluminum silicate fiber aqueous solution and the polyacrylamide are allowed to react at room temperature for 1-2 hours to obtain polyacrylamide modified aluminum silicate fiber; wherein the mass ratio of the aluminum silicate fiber to the polyacrylamide is 40-60:1.

[0051] It should be noted that the mass ratio of the aluminum silicate fiber to water is preferably but not limited to 1:0.2-0.3; and the reaction time of the aluminum silicate fiber aqueous solution and the polyacrylamide at room temperature is preferably but not limited to 1-2 hours, which can be adjusted accordingly according to actual conditions.

[0052] As a preferred scheme of the present application, the molecular weight of the polyacrylamide is 500-10 million.

[0053] It should be noted that the molecular weight of the polyacrylamide in the present application is preferably but not limited to 500-10 million.

[0054] As a preferred scheme of the present application, the soil solidifying agent is compounded from cement and fly ash at a mass ratio of 1:0.5-1. Preferably, the soil solidifying agent is compounded from cement and fly ash at a mass ratio of 1:1.

[0055] Specifically, the definition, requirements and classification of the soil solidifying agent in the present application comply with the definition, requirements and classification of the soft soil solidifying agent described in the local standard DB 31 / T 1483-2024 “Technical Specification for Self-compacting Filling of Construction Waste and Engineering Slurry”.

[0056] As a preferred scheme of the present application, the cement is Portland cement.

[0057] It should be noted that the cement is preferably but not limited to P.O 42.5 ordinary Portland cement.

[0058] As a preferred scheme of the present application, the fly ash is fly ash with a SiO2 content of less than 40%.

[0059] Specifically, the water requirement ratio of the fly ash is preferably less than 115%, the loss on ignition of the fly ash is preferably less than 15%, and the water content of the fly ash is preferably less than 3%.

[0060] The water requirement ratio of fly ash refers to the ratio of the water requirement of the cement paste (or mortar) mixed with fly ash to the water requirement of the reference cement paste (or mortar) under the same fluidity condition, which is used to evaluate the influence of fly ash on the water requirement of concrete.

[0061] The loss on ignition of fly ash refers to the percentage of the mass loss of unburned carbon and other organic matters (such as water and volatile matter) after oxidation in the high-temperature calcination process to the original mass.

[0062] The water content of fly ash refers to its inherent water content.

[0063] As shown in Figure 1 The preparation method of the fiber-modified anti-cracking fluidized solidified soil provided by the present application comprises the following steps:

[0064] Step S1, mixing construction engineering soil and water to form a mud slurry;

[0065] Step S2, adding polyacrylamide modified aluminum silicate fiber and soil solidifying agent into the mud slurry and mixing uniformly to obtain fiber-modified anti-cracking fluidized solidified soil.

[0066] Specifically, in the process of mixing construction engineering soil and water to form a mud slurry, after mixing the construction engineering soil and water, the mud slurry is obtained by stirring at a stirring rate of 50-100 r / min at room temperature for 1-5 minutes.

[0067] Preferably, the stirring rate is 60 r / min, and the stirring time is 3 minutes. After mixing the construction engineering soil and water, the mixture can be stirred by a stirring device, such as any model of a concrete mixer.

[0068] In order to better illustrate the effects of the fiber-modified anti-cracking fluidized solidified soil and the preparation method thereof provided by the present application, the following specific examples are carried out:

[0069] The sources of the components of the powder in each of the following examples are as follows:

[0070] The construction engineering soil is selected from the original soil at the construction site in Shanghai, and has a water content of 23 wt.%, a plastic limit of 18%, and a maximum dry density of 1.72 g / cm 3 .

[0071] The soil solidifying agent is compounded by cement and fly ash in a mass ratio of 1:1. The cement is 425 Portland cement, purchased from Hubei Guiyi New Building Material Co., Ltd.; and the fly ash is purchased from Zhejiang Huashi New Material Technology Co., Ltd.

[0072] The polyacrylamide modified aluminum silicate fiber is prepared by the inventors of the present application in the laboratory according to the following steps:

[0073] Dissolve the aluminum silicate fiber in water to obtain an aluminum silicate fiber aqueous solution; wherein the mass ratio of aluminum silicate fiber to water is 1:0.3;

[0074] Add polyacrylamide to the aluminum silicate fiber aqueous solution, and allow the aluminum silicate fiber aqueous solution and the polyacrylamide to react at room temperature for 2 hours to obtain polyacrylamide-modified aluminum silicate fiber; wherein the mass ratio of aluminum silicate fiber to polyacrylamide is 50:1.

[0075] The polyacrylamide has a molecular weight of 5-10 million, is an anionic APAM, and is purchased from Henan Saikeli Environmental Protection Technology Co., Ltd.; the aluminum silicate fiber is purchased from Lingshou County Taizhen Mineral Product Processing Factory.

[0076] Example 1

[0077] Prepare the following powder:

[0078] 85 kg of construction engineering soil, 0.1 kg of polyacrylamide-modified aluminum silicate fiber, and 15 kg of soil solidifying agent.

[0079] Step S1, mix the construction engineering soil and water at room temperature, use a concrete mixer, and stir at a stirring rate of 60 r / min for 3 min to form a mud slurry;

[0080] Step S2, add the polyacrylamide-modified aluminum silicate fiber and the soil solidifying agent to the mud slurry and mix uniformly to obtain fiber-improved anti-cracking fluidized solidified soil.

[0081] The water-solid ratio of water to powder is 0.5.

[0082] Example 2

[0083] Prepare the following powder:

[0084] 84.8 kg of construction engineering soil, 0.2 kg of polyacrylamide-modified aluminum silicate fiber, and 15 kg of soil solidifying agent.

[0085] Step S1, mix the construction engineering soil and water at room temperature, use a concrete mixer, and stir at a stirring rate of 60 r / min for 3 min to form a mud slurry;

[0086] Step S2, add the polyacrylamide-modified aluminum silicate fiber and the soil solidifying agent to the mud slurry and mix uniformly to obtain fiber-improved anti-cracking fluidized solidified soil.

[0087] The water-solid ratio of water to powder is 0.5.

[0088] Example 3

[0089] Prepare the following powder:

[0090] 84.6 kg construction engineering soil, 0.4 kg polyacrylamide modified aluminum silicate fiber, 15 kg soil solidifying agent.

[0091] Step S1, mix the construction engineering soil with water at room temperature, use the concrete mixer, stir at a stirring rate of 60 r / min, stir for 3 min, then form the mud slurry;

[0092] Step S2, add the polyacrylamide modified aluminum silicate fiber and the soil solidifying agent into the mud slurry and mix uniformly to obtain the fiber improved anti-cracking fluidized solidified soil.

[0093] Among them, the water-solid ratio of water and powder is 0.5.

[0094] Example 4

[0095] Prepare the following powder:

[0096] 84.4 kg construction engineering soil, 0.6 kg polyacrylamide modified aluminum silicate fiber, 15 kg soil solidifying agent.

[0097] Step S1, mix the construction engineering soil with water at room temperature, use the concrete mixer, stir at a stirring rate of 60 r / min, stir for 3 min, then form the mud slurry;

[0098] Step S2, add the polyacrylamide modified aluminum silicate fiber and the soil solidifying agent into the mud slurry and mix uniformly to obtain the fiber improved anti-cracking fluidized solidified soil.

[0099] Among them, the water-solid ratio of water and powder is 0.5.

[0100] Example 5

[0101] Prepare the following powder:

[0102] 84.2 kg construction engineering soil, 1 kg polyacrylamide modified aluminum silicate fiber, 15 kg soil solidifying agent.

[0103] Step S1, mix the construction engineering soil with water at room temperature, use the concrete mixer, stir at a stirring rate of 60 r / min, stir for 3 min, then form the mud slurry;

[0104] Step S2, add the polyacrylamide modified aluminum silicate fiber and the soil solidifying agent into the mud slurry and mix uniformly to obtain the fiber improved anti-cracking fluidized solidified soil.

[0105] Among them, the water-solid ratio of water and powder is 0.5.

[0106] Example 6

[0107] Prepare the following powder:

[0108] 84 kg of construction engineering soil, 1 kg of polyacrylamide modified aluminum silicate fiber, and 15 kg of soil solidifying agent.

[0109] Step S1, mix the construction engineering soil with water at room temperature, use the concrete mixer, stir at a stirring rate of 60 r / min, after stirring for 3 min, form the mud slurry;

[0110] Step S2, add the polyacrylamide modified aluminum silicate fiber and the soil solidifying agent into the mud slurry and mix uniformly to obtain the fiber improved anti-cracking fluidized solidified soil.

[0111] Wherein, the water-solid ratio of water and powder is 0.5.

[0112] In order to further verify the performance of the fiber improved anti-cracking fluidized solidified soil obtained in Examples 1-6, the fiber improved anti-cracking fluidized solidified soil obtained in Examples 1-6 was tested for the following performance:

[0113] 1. Rheological property test

[0114] The fluidity of the fiber improved anti-cracking fluidized solidified soil was tested according to the determination method in GB / T 2419-2005 "Cement mortar fluidity determination method", and the specific steps were as follows:

[0115] The same mass of fiber improved anti-cracking fluidized solidified soil was taken from the fiber improved anti-cracking fluidized solidified soil obtained in Examples 1-6, respectively.

[0116] For the fiber improved anti-cracking fluidized solidified soil obtained in each example, the following operations were performed:

[0117] The fiber improved anti-cracking fluidized solidified soil was divided into two layers and placed in the flow test mold, and the surface of the fiber improved anti-cracking fluidized solidified soil was scraped flat after tamping, and the circular mold was gently lifted upwards, and the maximum expansion diameter of the mixture was measured with a caliper.

[0118] 2. Compression and bending resistance performance test

[0119] The same mass of fiber improved anti-cracking fluidized solidified soil was taken from the fiber improved anti-cracking fluidized solidified soil obtained in Examples 1-6, respectively, and the compression and bending resistance performance test was performed according to "Cement mortar strength detection method (ISO method)" (GB / T 17671-2020), the CDT 1305-2 type microcomputer control electronic pressure testing machine was used for bending and compression strength test, and the bending and compression loading speed was set to (50±10) N / s and (2400±200) N / s, respectively. The compression test time was set to 3 days, 7 days and 28 days, respectively; the bending test time was set to 28 days.

[0120] 3. Water stability test

[0121] The same mass of fiber-reinforced anti-cracking fluidified solidified soil obtained from Examples 1-6 was taken to evaluate the mechanical performance stability index of the fiber-reinforced anti-cracking fluidified solidified soil in a saturated water environment according to the water stability coefficient K. The calculation formula is based on the ratio of the compressive strength of the saturated water specimen to that of the normal curing specimen, and the specific expression is: K = K1 / K2. In the formula, K1 is the compressive strength (MPa) of the specimen immersed in water until the curing age, and K2 is the compressive strength (MPa) of the specimen normally cured to the age.

[0122] The performance test results of the fiber-reinforced anti-cracking fluidified solidified soil obtained in Examples 1-6 are shown in Table 1 below.

[0123]

[0124] Table 1

[0125] As can be seen from Table 1, the fiber-reinforced anti-cracking fluidified solidified soil of Examples 1-6 exhibits significant fluidity, water stability, and compressive and flexural strength regularity under different mixing conditions.

[0126] From Examples 1 to 6, under the condition of different mixing amounts of polyacrylamide modified aluminum silicate fiber, the fluidity of the fiber-reinforced anti-cracking fluidified solidified soil basically remains between 325-328 mm with small fluctuations, indicating that the appropriate mixing of polyacrylamide modified aluminum silicate fiber has limited effect on the fluidity of the material, and can maintain good construction fluidity and pumpability, meeting the requirements of engineering applications. The water stability index shows a consistent upward trend with the increase of the mixing amount of polyacrylamide modified aluminum silicate fiber, increasing from 0.652 in Example 1 to 0.941 in Example 6, with a growth rate of 44.3%, indicating that the polyacrylamide modified aluminum silicate fiber forms a space reinforced network in the solidified soil body, significantly improving its water erosion resistance and structural retention capacity, and effectively reducing the strength degradation risk under the action of water environment.

[0127] In terms of compressive and flexural performance, the 3-day and 7-day compressive strengths remain in the stable interval of 0.66-0.68 MPa and 1.86-1.96 MPa, respectively, indicating that the polyacrylamide modified aluminum silicate fiber has little effect on the formation of early cementing strength and does not interfere with the main cementation process. The 28-day compressive strength increases from 3.78 MPa to 3.97 MPa, showing that the polyacrylamide modified aluminum silicate fiber has a certain promoting effect on long-term structural stability. The flexural strength is particularly outstanding, with the 28-day flexural strength increasing significantly from 0.095 MPa to 0.257 MPa, with an increase of 170.5%, indicating that the polyacrylamide modified aluminum silicate fiber plays a key role in improving the brittle failure mode of the solidified soil and enhancing its tensile and bending resistance, and its bridging effect and crack propagation inhibition capacity are fully embodied in the solidified material.

[0128] It should be noted that the above specific embodiments are only effectual description of the fiber modified anti-cracking fluidized solidified soil and the preparation method thereof provided by the present application in actual experiment process, and do not limit the technical solutions provided by the present application.

[0129] As can be seen from the above specific embodiments, the fiber modified anti-cracking fluidized solidified soil and the preparation method thereof provided by the present application, by taking the construction engineering soil, the polyacrylamide modified aluminum silicate fiber and the soil solidifying agent as the powder, fully utilizing the reinforcing effect of the fiber on the performance of the fluidized solidified soil, which is mainly due to the reinforcement and bridging effect of the polyacrylamide modified aluminum silicate fiber in the microstructure; the polyacrylamide modified aluminum silicate fiber has excellent properties such as easy dispersion, high strength, corrosion resistance and high temperature resistance after surface modification by polyacrylamide, and can improve the compressive strength and crack resistance of the fluidized solidified soil as a reinforcing material; the polyacrylamide modified aluminum silicate fiber forms a uniform three-dimensional network structure in the soil of the construction engineering soil, which can effectively hinder the initiation and expansion of microcracks, improve the original brittle failure mode of the solidified soil, and improve the crack resistance and ductility of the soil; the polyacrylamide modified aluminum silicate fiber enhances the cohesion and stress transfer capacity of the soil through physical entanglement and interfacial friction, thereby improving the bending, compressive and shear strengths, and when subjected to load or dry-wet cycle and other environmental effects, the fiber can disperse stress concentration and relieve the structural instability problem caused by volume change, thereby significantly improving the volume stability and durability; in addition, the polyacrylamide modified aluminum silicate fiber can inhibit the expansion of pore water channels and reduce the erosion rate, thereby enhancing the water stability of the soil.

[0130] The fiber modified anti-cracking fluidized solidified soil and the preparation method thereof according to the present application are described above with reference to the accompanying drawings in an exemplary manner. However, those skilled in the art should understand that various improvements can be made to the above fiber modified anti-cracking fluidized solidified soil and the preparation method thereof according to the present application without departing from the content of the present application. Therefore, the protection scope of the present application should be determined by the content of the claims

[0131] of the appended claims.

Claims

1. A fiber-modified, crack-resistant, fluidified soil, characterized in that, It comprises water and powder; wherein, The water-solid ratio of the water to the powder is 0.4-0.6; The powder comprises raw materials in the following mass fractions: 84-85 parts of construction engineering soil, 0.1-1 part of polyacrylamide modified aluminum silicate fiber, and 10-20 parts of soil solidifying agent.

2. The fiber-reinforced, crack-resistant, fluidified soil according to claim 1, wherein, The construction engineering soil is a mixture of construction waste fine powder and engineering slurry in any proportion.

3. The fiber-reinforced, modified, crack-resistant, soil-cement composition of claim 2, wherein, The particle size of the construction waste fine powder is 5-9.5 mm.

4. The fiber-reinforced, crack-resistant, fluidified soil of claim 2, wherein, The engineering slurry is waste slurry generated during construction or slurry prepared by stirring discarded soil with water.

5. The fiber-reinforced, crack-resistant, fluidified soil of claim 1, wherein, The preparation method of the polyacrylamide modified aluminum silicate fiber comprises the following steps: Dissolve aluminum silicate fiber in water to obtain an aluminum silicate fiber aqueous solution; wherein the mass ratio of the aluminum silicate fiber to the water is 1:0.2-0.3; Add polyacrylamide to the aluminum silicate fiber aqueous solution, and allow the aluminum silicate fiber aqueous solution and the polyacrylamide to react at room temperature for 1-2 hours to obtain polyacrylamide modified aluminum silicate fiber; wherein the mass ratio of the aluminum silicate fiber to the polyacrylamide is 40-60:

1.

6. The fiber-reinforced, modified, crack-resistant, soil-cement composition of claim 5, wherein, The molecular weight of the polyacrylamide is 5-10 million.

7. The fiber-reinforced, crack-resistant, fluidified soil of claim 1, wherein, The soil solidifying agent is compounded from cement and fly ash in a mass ratio of 1:0.5-1.

8. The fiber-reinforced, modified, crack-resistant, soil-cement composition of claim 7, wherein, The cement is Portland cement.

9. The fiber-reinforced, modified, crack-resistant, soil-cement composition of claim 7, wherein, The fly ash is fly ash with a SiO2 content of less than 40%.

10. A method of producing a fiber-modified, crack-resistant, fluidified soil according to any one of claims 1 to 9, characterized in that, It comprises the following steps: Mix the construction engineering soil and the water to form a slurry; Mix the polyacrylamide modified aluminum silicate fiber and the soil solidifying agent into the slurry to obtain fiber-improved anti-cracking fluidized solidified soil.

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