1. The composite additive for the grouting slurry of the marine sludge stratum is characterized by comprising the following components in parts by weight: the composition comprises the following components in percentage by mass: 11.6-12.3 parts of trimethyl ammonium chloride, 0.8-1.0 part of sodium phosphite, 66.5-67.9 parts of polyoxyethylene ether, 2.7-3.0 parts of hydroxypropyl methyl cellulose, 1.4-1.6 parts of ammonium persulfate, 6.6-7.3 parts of polyacrylamide, 2.7-3.0 parts of potassium sodium tartrate, 3.2-3.5 parts of calcium formate and 2.3-2.6 parts of sodium dodecyl benzene sulfonate.

2. The composite additive for grouting slurry of the marine sludge formation, according to claim 1, is characterized in that: the preparation process of the composite additive comprises the following steps: adding trimethyl ammonium chloride, acrylamide and polyoxyethylene ether into deionized water, dissolving at 25-35 ℃, keeping the temperature for 15-25min to obtain slurry, introducing nitrogen into the slurry to drive oxygen, then adding sodium phosphite and ammonium persulfate, heating to 55-65 ℃, reacting to obtain a polymer product, and then mixing the polymer product, calcium formate, sodium dodecyl benzene sulfonate, sodium potassium tartrate and hydroxypropyl methyl cellulose to obtain the composite additive.

3. The composite additive for grouting slurry of the marine sludge formation, according to claim 2, is characterized in that: and introducing nitrogen into the slurry to drive oxygen for more than 15 min.

4. The composite additive for grouting slurry of the marine sludge formation, according to claim 2, is characterized in that: the reaction time is 4-6 h.

5. The composite additive for grouting slurry of the marine sludge formation, according to claim 2, is characterized in that: the mixing process is carried out in a double-motion stirring barrel, and the mixing time is 25-50 min.

6. The application of the composite additive for the grouting slurry of the marine sludge formation as claimed in any one of claims 1 to 5, wherein the composite additive comprises the following components in percentage by weight: the composite additive is used for the grouting slurry of the sea sludge stratum, and the grouting slurry of the sea sludge stratum comprises the following components in percentage by mass: 62.7-63.5% of cement: 0.1-0.3% of composite additive: 36.4-37.0% of water.

7. The application of the composite additive for the grouting slurry of the marine sludge formation as claimed in any one of claims 6, wherein the composite additive comprises the following components in percentage by weight: the preparation process of the marine sludge stratum grouting slurry comprises the steps of firstly pouring cement into a stirring tank, then injecting clear water, and stirring for 12-18 min; and (4) obtaining a mixture, then adding the composite additive, and stirring for 8-14min to obtain the sea sludge stratum grouting slurry.

Background

With the development of society, a traffic transportation system which is continuously improved and the transportation service capability which is greatly improved provide higher requirements for the roadbed quality of bridge roads. For this reason, the road-bearing strata must be consolidated.

The current grouting technology is widely applied to reinforcement treatment of foundations, particularly soft soil foundations, due to the advantages of simple and convenient construction, low cost, small influence on the surrounding environment and the like. The slurry is pressed into the loose soil body to be reinforced along the drill hole under a certain grouting pressure, and the compactness and the bearing capacity of the soil body are obviously improved after the pores of the soil body are subjected to filling, consolidation and compaction. However, when a traffic network is laid in a coastal beach area, the common marine sludge in the area brings great difficulty to the treatment of road foundations by the mechanical characteristics of three-high two-low, and when the traditional grouting technology is used, the problems of great increase of cement consumption, easy dilution of slurry, poor stability, low soil consolidation strength and the like occur.

Researches show that the performance of the cement slurry can be obviously improved and the stability of the cement slurry can be enhanced after the cement slurry is added with the additive. The prior admixtures are divided into an admixture for improving the flowing property of the grout, an admixture for adjusting the setting time and the hardening property, an admixture for improving the durability and an admixture for improving other properties of the grout according to main functions, but the performances of the admixture are generally single and can not meet various requirements, and the grouting grout has the characteristics of good flowing property, long pumping period, high strength, good corrosion resistance and the like in the requirement of the marine sludge soft soil stratum. Aiming at the problems of poor reinforcing effect and large cement consumption of the existing grouting slurry in the sea sludge stratum, the composite additive is actually necessary to be developed by fully combining the characteristics of the sea sludge, the use effect of the grouting technology in the sea sludge stratum is improved by using the additive and optimizing the formula of the grouting slurry, the bearing capacity of the sea soft soil is improved, and the engineering cost is reduced.

Disclosure of Invention

Aiming at the problem that the prior grouting technology has poor reinforcing effect in a marine sludge stratum with the characteristics of three heights, two heights and two heights, the invention aims to provide the composite additive for the grouting slurry of the marine sludge stratum and the application thereof.

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

the invention relates to a composite additive for grouting slurry of a marine sludge stratum, which comprises the following components in percentage by mass: 11.6-12.3 parts of trimethyl ammonium chloride, 0.8-1.0 part of sodium phosphite, 66.5-67.9 parts of polyoxyethylene ether, 2.7-3.0 parts of hydroxypropyl methyl cellulose, 1.4-1.6 parts of ammonium persulfate, 6.6-7.3 parts of polyacrylamide, 2.7-3.0 parts of potassium sodium tartrate, 3.2-3.5 parts of calcium formate and 2.3-2.6 parts of sodium dodecyl benzene sulfonate.

Specifically, the type of the trimethyl ammonium chloride is colorless transparent liquid DMC, and the molecular weight is 207.7. Specifically, the sodium phosphite is white crystal powder SP, and the molecular weight of the sodium phosphite is 216.04.

Specifically, the polyoxyethylene ether is a milky solid TPEG in type, has a molecular weight of 2200, and can enhance the corrosion resistance and slump retention of the slurry.

Specifically, the hydroxypropyl methylcellulose is white granular powdery HPMC with the molecular weight of 59.08708, and can improve the pumpability of the slurry.

Specifically, the type of the ammonium persulfate is white crystal APS, and the molecular weight is 228.2.

Specifically, the polyacrylamide type is PAA in a white solid state, and the molecular weight is 71.0779.

Specifically, the potassium sodium tartrate is colorless transparent crystal PS with molecular weight of 210.23,

specifically, the calcium formate is white crystal CaF, the molecular weight is 130.0, the time interval from the pumpable period to the initial setting of the slurry can be effectively shortened, and the hardening of the slurry is accelerated.

Specifically, the sodium dodecyl benzene sulfonate is light yellow powder K12, and has a molecular weight of 348.48.

In a preferred scheme, the preparation process of the composite admixture is as follows: adding trimethyl ammonium chloride, acrylamide and polyoxyethylene ether into deionized water, dissolving at 25-35 ℃, keeping the temperature for 15-25min to obtain slurry, introducing nitrogen into the slurry to drive oxygen, then adding sodium phosphite and ammonium persulfate, heating to 55-65 ℃, reacting to obtain a polymer product, and then mixing the polymer product, calcium formate, sodium dodecyl benzene sulfonate, sodium potassium tartrate and hydroxypropyl methyl cellulose to obtain the composite additive.

Further preferably, nitrogen is introduced into the slurry to drive oxygen for more than 15 min.

Further preferably, the reaction time is 4-6 h.

In the actual operation process, colloidal branched copolymer is obtained after reaction, and then white high molecular polymer solid products are obtained by washing and drying through acetone.

Further preferably, the mixing process is carried out in a double-motion stirring barrel, and the mixing time is 25-50 min. The rotation in the double-motion stirring barrel and the rotation of the blades inside the charging barrel are utilized to drive the mutual diffusion, convection and shearing premixing of the powder, so that the composite admixture is obtained.

In the invention, a large number of experiments are carried out on the compound admixture to compound various components, the inventor finds that the compounding of the components can generate synergistic interaction, and finally the compound admixture with multiple modification effects is obtained.

The invention also provides an application of the composite additive for the marine sludge stratum grouting slurry, wherein the composite additive is used for the marine sludge stratum grouting slurry, and the marine sludge stratum grouting slurry comprises the following components in percentage by mass: 62.7-63.5% of cement: 0.1-0.3% of composite additive: 36.4-37.0% of water.

In the invention, the type of the cement is PC32.5 ordinary portland cement, the source of the cement adopts the principle of near to reduce the transportation cost of cement raw materials, the water is industrial clear water, and the water has no impurities.

Preferably, the preparation process of the marine sludge stratum grouting slurry comprises the steps of firstly pouring cement into a stirring tank, then injecting clear water, and stirring for 12-18 min; and (4) obtaining a mixture, then adding the composite additive, and stirring for 8-14min to obtain the sea sludge stratum grouting slurry.

Advantageous effects

The invention provides a composite additive, which is doped into the sea sludge stratum grouting slurry, so that the cement consumption can be reduced, the stability, pumpability, corrosion resistance and strength characteristics of the slurry can be obviously enhanced, and the bearing capacity of the sea sludge stratum is obviously improved. In the process of applying the composite additive to the grouting slurry of the marine sludge formation, cement, clear water and the additive are sequentially added for stirring twice, so that the components of the material prepared from the grouting slurry of the marine sludge formation are mixed more uniformly. In the invention, only 0.1-0.3% of composite additive is needed to be added into the grouting slurry of the marine sludge stratum, on one hand, the dispersibility of cement particles in the grouting slurry is improved, the cement argillization speed and degree are increased, on the other hand, the water-cement ratio of the slurry is reduced, the fluidity of the slurry is improved, the marine corrosion resistance of the grouting stone body is enhanced, and the bearing capacity of a soft soil foundation is improved by adjusting the hydration reaction of the slurry to absorb and extrude part of water in a marine sludge layer.

Detailed Description

In order to facilitate a better understanding of the invention, the following examples are given which are included within the scope of the invention and are not intended to limit the scope of the invention.

Example 1:

the invention provides a marine sludge stratum grouting slurry, a formula of a composite additive in the grouting slurry and a preparation method thereof, wherein the formula comprises the following steps:

1. the feed comprises the following raw materials in parts by weight: 11.6 parts of trimethyl ammonium chloride, 1.0 part of sodium phosphite, 67.9 parts of polyoxyethylene ether, 3.0 parts of hydroxypropyl methyl cellulose, 1.4 parts of ammonium persulfate, 6.6 parts of polyacrylamide, 2.7 parts of potassium sodium tartrate, 3.5 parts of calcium formate and 2.3 parts of sodium dodecyl benzene sulfonate;

2. firstly, trimethyl ammonium chloride, acrylamide and polyoxyethylene ether are taken, deionized water is added to be dissolved at the temperature of 30 ℃, water bath is carried out for 20 minutes at constant temperature, then nitrogen is introduced to remove oxygen for 15 minutes, and then sodium phosphite and ammonium persulfate are added to be heated to 60 ℃ for continuous reaction for 5 hours, so as to obtain the colloidal nodular branch copolymer. Washing and drying the mixture by acetone to obtain a white high molecular polymer solid product;

3. then adding calcium formate, sodium dodecyl benzene sulfonate, potassium sodium tartrate, hydroxypropyl methylcellulose and the obtained polymer product into a double-motion stirring barrel, and driving the powder to mutually diffuse, convect and shear and premix for 30min by using the rotation of a charging barrel and the rotation of blades inside the charging barrel to obtain a composite additive;

4. and finally, weighing 0.3% of the composite additive, 63.5% of C35 ordinary portland cement and 36.2% of industrial water according to the mass, pouring the mixture into a cement stirrer together, and fully stirring for 12-14 min to prepare the grouting slurry suitable for the marine sludge stratum.

Example 2:

the invention provides a marine sludge stratum grouting slurry, a formula of a composite additive in the grouting slurry and a preparation method thereof, wherein the formula comprises the following steps:

1. the feed comprises the following raw materials in parts by weight: 12.3 parts of trimethyl ammonium chloride, 0.8 part of sodium phosphite, 66.5 parts of polyoxyethylene ether, 2.7 parts of hydroxypropyl methyl cellulose, 1.6 parts of ammonium persulfate, 7.3 parts of polyacrylamide, 3.0 parts of potassium sodium tartrate, 3.2 parts of calcium formate and 2.6 parts of sodium dodecyl benzene sulfonate;

2. firstly, trimethyl ammonium chloride, acrylamide and polyoxyethylene ether are taken, deionized water is added to be dissolved at the temperature of 30 ℃, water bath is carried out for 20 minutes at constant temperature, then nitrogen is introduced to remove oxygen for 15 minutes, and then sodium phosphite and ammonium persulfate are added to be heated to 60 ℃ for continuous reaction for 5 hours, so as to obtain the colloidal nodular branch copolymer. Washing and drying the mixture by acetone to obtain a white high molecular polymer solid product;

3. then adding calcium formate, sodium dodecyl benzene sulfonate, potassium sodium tartrate, hydroxypropyl methylcellulose and the obtained polymer product into a double-motion stirring barrel, and driving the powder to mutually diffuse, convect and shear and premix for 30min by using the rotation of a charging barrel and the rotation of blades inside the charging barrel to obtain a composite additive;

4. and finally, weighing 0.3% of the composite additive, 63.5% of C35 ordinary portland cement and 36.2% of industrial water according to the mass, pouring the mixture into a cement stirrer together, and fully stirring for 12-14 min to prepare the grouting slurry suitable for the marine sludge stratum.

Comparative example 1

The preparation method of the composite admixture is the same as that of example 1, except that polyoxyethylene ether, polyacrylamide, sodium dodecylbenzenesulfonate, hydroxypropylmethylcellulose and calcium formate are absent from raw materials for preparing the composite admixture.

Comparative example 2

The same procedure as in example 2 was conducted except that polyoxyethylene ether was absent from the raw materials for preparing the composite admixture.

Comparative example 3

The same procedure as in example 2 was followed, except that the raw materials for preparing the composite admixture lacked polyacrylamide.

Comparative example 4

The preparation method was the same as that of example 2 except that sodium dodecylbenzenesulfonate was absent from the raw materials for preparing the composite admixture.

Comparative example 5

The preparation method is the same as that of example 2, except that hydroxypropylmethylcellulose is absent in the raw materials for preparing the composite admixture.

Comparative example 6

The same procedure as in example 2 was followed, except that calcium formate was absent from the raw materials used to prepare the composite admixture.

The grouting slurry prepared in the comparative examples 1-6 and examples 1-2 was subjected to pumpability, initial setting time, water-separation rate and corrosion resistance measurement based on an indoor test, and stone bodies formed after the slurry was solidified were processed to prepare test samples, and the 1d, 7d and 28d compressive strength and flexural strength tests were carried out using an MTS-322 hydraulic pressure testing machine.

Table 1 slurry test results

TABLE 2 calculus body test results

As can be seen from tables 1 and 2: the invention has the synergistic strengthening effect in the preparation of the composite additive by adding polyoxyethylene ether, polyacrylamide, sodium dodecyl benzene sulfonate, hydroxypropyl methylcellulose and calcium formate, so that the performance of the grouting slurry is obviously improved, and the grouting slurry is mainly shown in the following aspects:

(1) the pumpability period of the slurry is prolonged, the slurry keeps good fluidity in the pumpability period, and the time interval from the pumpability period to the initial setting time of the slurry is short;

(2) the corrosion resistance of the slurry is obviously improved;

(3) the water precipitation rate of the slurry is reduced to some extent, which directly shows that the stability of the slurry is better, and the slurry is continuously excessively lost in a soft soil layer of the marine sludge in the grouting process, so that the strength of the solidified stone body is higher;

(4) the grout stone body has the performance of fast early strength increase and high later strength, and can improve the grout grouting reinforcement and water plugging treatment effects, so that the bearing capacity of the foundation is further enhanced.