Anti-scouring environment-friendly sludge soil curing agent as well as use method and application thereof

Abstract

The invention discloses an anti-scouring environment-friendly sludge soil curing agent as well as a use method and application of the anti-scouring environment-friendly sludge soil curing agent. The anti-scouring environment-friendly sludge soil curing agent comprises a first component and a second component, and the ratio of the first component to the second component is 1: 1; the first component comprises ammonium dihydrogen phosphate, fly ash and anhydrous borax, and the ratio of the ammonium dihydrogen phosphate to the fly ash to the anhydrous borax is 1.0: 2.0: 0.25; the second component comprises dead burned magnesium oxide, slag powder and a composite water reducing agent, and the ratio of the dead burned magnesium oxide to the slag powder to the composite water reducing agent is 1.0: 0.25: 0.002. The curing agent provided by the invention has good physical and mechanical properties and environmental adaptability, and also has the characteristic of rapid curing. And moreover, the corrosion resistance to chloride ions and sulfate ions is achieved, heavy metal ions and radioactive ions in the surrounding environment can be consolidated, and therefore extremely high application value and practical significance are shown in reinforcement treatment of polluted offshore silt soil and coastal salinized soil.

Description

Technical Field

[0001] This application belongs to the technical field of building materials and soil solidification, and specifically relates to an anti-erosion environmental protection type silt soil solidifying agent, its usage method and its application. Background Technique

[0002] Silt soil is a kind of soil with high viscosity, weak water permeability and high compressibility. Due to its characteristics such as high water content, low strength and easy deformation, it brings many challenges to engineering construction and foundation treatment. The performance of the solidifying agent plays a crucial role in the soil solidification effect. The mainstream soil solidifying agents in the current market, such as silicate cement solidifying agents and chemical solidifying agents, all have obvious deficiencies. Among them, although silicate cement solidifying agents are low in price and widely used, their stone formation rate is low, their strength is insufficient, their setting time is long, their diffusibility is poor, and their durability is not good under the erosion of chloride ions and sulfate ions. In addition, their high-pH slurries may also have an adverse impact on the environment. Although chemical solidifying agents are superior to silicate cement solidifying agents in terms of fluidity and diffusibility, they are high in price, the strength of the stone body is low, they are easy to age, their service life is short, and their bonding performance with clay is not good especially in humid environments. More importantly, most chemical solidifying agents are toxic and may cause environmental pollution.

[0003] In view of the fact that there is no soil solidifying agent in the current market that can overcome the above problems and is specifically for silt soil reinforcement, it is particularly important to develop a new type of solidifying agent with excellent physical and mechanical properties, good durability and suitable for the special engineering environment of silt soil. Summary of the Invention

[0004] Aiming at the shortcomings or deficiencies of the above-mentioned existing technologies, the technical problem to be solved by this application is to provide an anti-erosion environmental protection type silt soil solidifying agent, its usage method and its application.

[0005] To solve the above technical problems, this application is realized through the following technical solutions:

[0006] This application proposes an anti-erosion environmental protection type silt soil solidifying agent, including: a first component and a second component, and the ratio of the first component to the second component is 1:1;

[0007] The first component includes: ammonium dihydrogen phosphate, fly ash and anhydrous borax, and the ratio of ammonium dihydrogen phosphate, fly ash and anhydrous borax is 1.0:2.0:0.25;

[0008] The second component includes: dead-burned magnesia, slag powder and a composite water reducer, and the ratio of dead-burned magnesia, slag powder and the composite water reducer is 1.0:0.25:0.002.

[0009] Further, for the above anti-erosion environmental protection type silt soil solidifying agent, the composite water reducing agent is composed of a polycarboxylate water reducing agent and a melamine water reducing agent in a ratio of 5:1 to 6:1.

[0010] The present application also provides a method for using an anti-erosion environmental protection type silt soil solidifying agent, and the above anti-erosion environmental protection type silt soil solidifying agent is used.

[0011] Further, for the above method of use, it includes the following steps:

[0012] Mix the first component in proportion, add water, and stir evenly to form the first slurry; mix the second component in proportion, add water, and stir evenly to form the second slurry.

[0013] Mix the first slurry and the second slurry evenly in a ratio of 1:1 to form a grouting liquid.

[0014] Further, for the above method of use, when using a mixing pile, the water content added to the first slurry is 25% of the mass of the first component, and the water content added to the second slurry is 25% of the mass of the second component; when using a jet grouting pile, the water content added to the first slurry is 50% of the mass of the first component, and the water content added to the second slurry is 50% of the mass of the second component; when using compaction grouting, the water content added to the first slurry is 70% of the mass of the first component, and the water content added to the second slurry is 70% of the mass of the second component.

[0015] The present application also provides an application of an anti-erosion environmental protection type silt soil solidifying agent, and the above anti-erosion environmental protection type silt soil solidifying agent is applied.

[0016] Further, for the above application, the solidifying agent is added to the silt soil to be reinforced.

[0017] Further, for the above application, the addition amount of the grouting liquid formed by the solidifying agent is 40 kg / m 3 ~55 kg / m 3 of silt soil.

[0018] Further, for the above application, the pressure of injecting the grouting liquid formed by the solidifying agent into the silt soil is 1.0 MPa to 2.0 MPa; and / or, the injection speed of the grouting liquid formed by the solidifying agent into the silt soil is 15 L / min to 25 L / min.

[0019] Compared with the prior art, the present application has the following technical effects:

[0020] The curing agent proposed in this application has good physical and mechanical properties and environmental adaptability, and also has the characteristic of rapid curing. Moreover, it has the ability to resist the erosion of chloride ions and sulfate ions, and can solidify heavy metal ions and radioactive ions in the surrounding environment, thus showing extremely high application value and practical significance in the reinforcement treatment of polluted offshore silt and coastal saline soil.

[0021] The application method proposed in this application makes the curing agent applicable to various silt reinforcement constructions such as jet grouting piles, mixing piles, and compaction grouting, ensuring the feasibility of construction operations and achieving the optimal effect of silt reinforcement. Specific Embodiments

[0022] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0023] In one embodiment of this application, an anti-scouring and environmentally friendly silt curing agent includes: a first component and a second component, and the ratio of the first component to the second component is 1:1;

[0024] The first component includes: ammonium dihydrogen phosphate, fly ash, and anhydrous borax, and the ratio of ammonium dihydrogen phosphate, fly ash, and anhydrous borax is 1.0:2.0:0.25;

[0025] The second component includes: dead-burned magnesia, slag powder, and a composite water reducer, and the ratio of dead-burned magnesia, slag powder, and the composite water reducer is 1.0:0.25:0.002.

[0026] Specifically, the first component is an acidic component, and the second component is an alkaline component.

[0027] Among them, the fly ash in the first component can play the role of a filler and the morphological effect of spherical particles, improving the fluidity of the slurry; borax dissolves to be weakly alkaline, and adding it to the first component can promote the dissolution of ammonium dihydrogen phosphate. If borax is added to the second component, borax will react with MgO after dissolution, resulting in an increase in the viscosity of the slurry formed by the second component.

[0028] The slag powder in the second component can improve the mechanical properties and water resistance while ensuring the working performance of the slurry; the composite water reducer is composed of a polycarboxylate water reducer and a melamine water reducer mixed in a ratio of 5:1, making the fluidity of the first slurry and the second slurry mentioned below similar.

[0029] The ammonium dihydrogen phosphate in the first component is soluble in water, while the solubility of magnesium oxide and slag powder in the second component is very poor. Therefore, the water demand of the first component is lower than that of the second component. To ensure that the two components have similar fluidity under the same water-binder ratio, a composite water reducer of 0.002 of the total mass of dead-burned magnesium oxide and slag powder needs to be added to the second component; after adding the polycarboxylate water reducer, the water demand of the second component can be significantly reduced and the fluidity of the slurry can be improved. However, if the polycarboxylate water reducer is used alone, the stability of the second component will be poor, and the formed slurry will quickly bleed and segregate in a short time. Therefore, a melamine water reducer is added and used together with the polycarboxylate water reducer. The dispersion effect of the melamine water reducer can ensure the stability of the second component, and there will be no bleeding and segregation within 30 minutes after the mixing is completed.

[0030] The present application also provides a method for using an anti-erosion environmental protection type silt soil solidifying agent, including the following steps:

[0031] Mix the first component in proportion and add water, and stir evenly to form the first slurry; mix the second component in proportion and add water, and stir evenly to form the second slurry;

[0032] Mix the first slurry and the second slurry evenly in a ratio of 1:1 to form a grouting slurry.

[0033] Subsequently, use special construction equipment to mix the grouting slurry with the soil to be reinforced.

[0034] Specifically, when used for mixing piles, the water content of the first slurry is 25% of the mass of the first component, and the water content of the second slurry is 25% of the mass of the second component; when used for jet grouting piles, the water content of the first slurry is 50% of the mass of the first component, and the water content of the second slurry is 50% of the mass of the second component; when used for compaction grouting, the water content of the first slurry is 70% of the mass of the first component, and the water content of the second slurry is 70% of the mass of the second component; the performance parameters of the solidifying agent in the above three cases are shown in Table 1.

[0035] Table 1 Performance Indexes of the Solidifying Agent

[0036]

[0037] The present application also provides two comparative examples for effect comparison, specifically as follows:

[0038] Comparative Example 1

[0039] Mix magnesium phosphate cement with 6% of borax based on the mass of magnesium phosphate cement and 0.1% of polycarboxylate water reducer based on the mass of magnesium phosphate cement, and then add 70% of water based on the total mass of magnesium phosphate cement, borax and polycarboxylate water reducer, and the measured performance is as shown in Table 2 below.

[0040] Table 2 Performance Indexes of Curing Agent in Comparative Example 1

[0041]

[0042] As can be seen from the data in Table 2, the compressive strength and flexural strength of Comparative Example 1 are significantly lower than the corresponding indexes of the high-performance curing agent of this application. Its resistance to chloride salt erosion and sulfate erosion is poor, and its water resistance cannot meet the usage requirements in underwater or humid environments.

[0043] Comparative Example 2

[0044] Add 70% of the mass of magnesium phosphate cement in the magnesium phosphate cement, and stir quickly. The measured performance is as shown in Table 3 below:

[0045] Table 3 Performance Indexes of Curing Agent in Comparative Example 2

[0046]

[0047] As can be seen from the data in Table 3, in addition to the strength of Comparative Example 2 being significantly lower than the corresponding indexes of the high-performance curing agent of this application, its resistance to saline-alkali erosion is poor and its water resistance cannot meet the usage requirements in underwater or humid environments. Moreover, its fluidity and setting time also cannot meet the construction operation requirements.

[0048] This application also proposes an application of an erosion-resistant and environment-friendly silt curing agent. There is a vast low-lying area in a coastal area, which is mainly composed of silty soil. Due to the low soil bearing capacity and easy liquefaction, it has brought great challenges to the local construction and development. In order to meet the needs of infrastructure construction in this area, after detailed on-site surveys and soil physical and mechanical property tests, it is decided to use this curing agent to reinforce this silt area. The reinforcement construction method is compaction grouting, and the following steps are specifically adopted:

[0049] 1) Prepare the first slurry: After mixing the first component evenly in proportion, add 70% of its mass of water, and use a high-speed mixer to stir for 2 minutes until a uniform first slurry is formed; prepare the second slurry: After mixing the second component evenly in proportion, add 70% of its mass of water, and use a high-speed mixer to stir for 2 minutes to form a uniform second slurry.

[0050] 2) Obtain the grouting liquid: Quickly mix the prepared first slurry and second slurry evenly in a ratio of 1:1 to form the grouting liquid. During this process, it should be ensured that the first slurry and the second slurry are fully mixed to avoid stratification or precipitation.

[0051] 3) Inject the grouting liquid: Use a grouting pump to inject the above grouting liquid into the silt body to be reinforced. In this example, the arrangement of the grouting holes follows the principle of interlacing and uniform distribution, and the dosage of the grouting liquid is 50 kg / m 3Soft soil, grouting pressure is 1.5 MPa, and grouting speed is 20 L / min.

[0052] 4) Curing and solidification: After the soft soil reinforcement is completed, the reinforced soil mass is cured for 3 days. During the curing process, the soil mass should be kept moist to avoid poor reinforcement effect caused by too fast drying.

[0053] 5) Detection and evaluation: After curing, the various properties of the reinforced soil mass are detected and evaluated. The specific detection results are shown in Tables 4 to 7 below.

[0054] Table 4 Physical and mechanical properties of the soil mass before and after reinforcement, such as strength and deformation

[0055]

[0056] Table 5 Anti-erosion performance of the soil mass before and after reinforcement

[0057]

[0058] Table 6 Acid-base property of the soil mass before and after reinforcement

[0059]

[0060] Table 7 Contents of free heavy metal ions and radioactive ions in the soil mass before and after reinforcement

[0061]

[0062] In summary, the advantages of this application are as follows:

[0063] 1) Convenient and easy to use: The two-component formulation effectively overcomes the drawback of the short setting time of the existing curing agent, greatly facilitating the on-site construction operation and laying a solid foundation for large-scale application.

[0064] 2) Quick solidification: The optimized component design enables the curing agent to solidify rapidly during use, effectively shortening the construction period and improving the construction efficiency. For projects that need to be put into use quickly, it has extremely high economic and social benefits.

[0065] 3) High strength and good erosion resistance: Through the raw material ratio of this application, the physical and mechanical properties of the curing agent are significantly enhanced, the deformation amount is greatly reduced, effectively solving the problems of insufficient bearing capacity and easy deformation of the silt foundation, enabling it to adapt to various complex environmental conditions such as offshore soft soil and coastal saline soil.

[0066] 4) Excellent water resistance and anti-erosion performance: This application not only has good water resistance, but also its anti-erosion performance is significantly improved. The soil mass after application can remain stable during long-term use, so it is particularly suitable for the reinforcement treatment of submarine soft soil and coastal saline soil.

[0067] 5) Green energy conservation: The curing agent components proposed in this application all meet environmental protection standards. Among them, ammonium dihydrogen phosphate, fly ash, anhydrous borax, dead-burned magnesia, and slag powder are by-products of industrial production, reflecting the concept of green and energy conservation.

[0068] 6) Environmentally friendly: Using this application will not only have no negative impact on the surrounding environment, but also effectively solidify heavy metal ions such as Hg, Cd, Pb, Cr, etc., and radioactive ions such as Pu, Np, Am, Cs, Sr, etc. in the surrounding environment, showing environmental friendliness.

[0069] 7) Moderate price: The cost of this application is slightly higher than that of silicate cement curing agents, but much lower than that of other types of chemical curing agents, providing users with a more cost-effective choice and meeting the needs of different users.

[0070] 8) Wide applicability: This application is not only applicable to the reinforcement treatment of soft mud, but also applicable to the reinforcement treatment of other types of soft soil foundations. In addition, its construction methods are flexible and diverse, applicable to various soft mud reinforcement construction methods such as jet grouting piles, mixing piles, and compaction grouting, showing high engineering applicability.

[0071] The above embodiments are only used to illustrate the technical solutions of this application rather than to limit them. The present application has been described in detail with reference to the preferred embodiments. Those of ordinary skill in the art should understand that the technical solutions of this application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of this application, and all should be covered within the scope of the claims of this application.

Claims

1. An anti-erosion environmental protection silt solidifying agent, characterized in that, Comprising: A first component and a second component, the ratio of the first component to the second component being 1:1; The first component comprises: ammonium dihydrogen phosphate, fly ash and anhydrous borax, and the ratio of ammonium dihydrogen phosphate, fly ash and anhydrous borax is 1.0:2.0:0.25; The second component comprises: dead-burned magnesia, slag powder and a composite water reducer, and the ratio of dead-burned magnesia, slag powder and the composite water reducer is 1.0:0.25:0.

002.

2. The anti-erosion environmental protection silt solidifying agent according to claim 1, characterized in that, The composite water reducer is composed of a polycarboxylate water reducer and a melamine water reducer in a ratio of 5:1 to 6:

1.

3. A method for using an anti-erosion environmental protection silt solidifying agent, characterized in that, Use the anti-erosion environmental protection silt soil solidifying agent according to claim 1 or 2.

4. The usage method according to claim 3, characterized in that Including the following steps: Mix the first component in proportion and add water, and stir evenly to form a first slurry; mix the second component in proportion and add water, and stir evenly to form a second slurry; Mix the first slurry and the second slurry evenly in a ratio of 1:1 to form a grouting liquid.

5. The usage method according to claim 4, characterized in that, When using a mixing pile, the water content of the first slurry is 25% of the mass of the first component, and the water content of the second slurry is 25% of the mass of the second component; or, when using a jet grouting pile, the water content of the first slurry is 50% of the mass of the first component, and the water content of the second slurry is 50% of the mass of the second component; or, when using compaction grouting, the water content of the first slurry is 70% of the mass of the first component, and the water content of the second slurry is 70% of the mass of the second component.

6. Application of an anti-scouring environmental protection type silt solidifying agent, characterized in that Apply the anti-erosion environmental protection silt soil solidifying agent according to any one of claims 1 to 5.

7. The application according to claim 6, characterized in that, Inject the grouting liquid formed by the solidifying agent into the silt soil to be reinforced.

8. The application according to claim 7, wherein The addition amount of the grouting liquid formed by the curing agent is 40 kg / m 3 ~55 kg / m 3 Soft clay.

9. The application according to claim 7, wherein The pressure for injecting the grouting liquid formed by the solidifying agent into the silt soil is 1.0 MPa to 2.0 MPa; and / or, the injection speed of the grouting liquid formed by the solidifying agent into the silt soil is 15 L / min to 25 L / min.

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