阅读说明：本技术 一种改性层状硅酸盐及其制备方法与应用 (Modified phyllosilicate, preparation method and application thereof ) 是由 王肇嘉 李扬 黄天勇 房桂明 陈旭峰 张增寿 于 2021-01-08 设计创作，主要内容包括：本发明涉及建筑材料和化学建材技术领域,尤其涉及一种改性层状硅酸盐及其制备方法与应用。所述改性层状硅酸盐的制备方法包括如下步骤：(1)以层状硅酸盐和碱溶液为原料,搅拌均匀后,烘干得羟基活化的层状硅酸盐；(2)将所述羟基活化的层状硅酸盐和偶联剂反应1～2h后,在120～180℃下焙烧2～3h。利用上述方法制得的改性层状硅酸盐在防腐蚀混凝土中使用时,能够增加混凝土的疏水性,混凝土抗蚀系数提升16～23％。(The invention relates to the technical field of building materials and chemical building materials, in particular to modified phyllosilicate and a preparation method and application thereof. The preparation method of the modified phyllosilicate comprises the following steps: (1) taking layered silicate and alkali solution as raw materials, uniformly stirring, and drying to obtain hydroxyl activated layered silicate; (2) and (3) reacting the hydroxyl activated layered silicate with a coupling agent for 1-2 h, and then roasting at 120-180 ℃ for 2-3 h. When the modified phyllosilicate prepared by the method is used in anti-corrosion concrete, the hydrophobicity of the concrete can be increased, and the corrosion resistance coefficient of the concrete is improved by 16-23%.)

1. The preparation method of the modified phyllosilicate is characterized by comprising the following steps:

(1) taking layered silicate and alkali solution as raw materials, uniformly stirring, and drying to obtain hydroxyl activated layered silicate;

(2) and (3) reacting the hydroxyl activated layered silicate with a coupling agent for 1-2 h, and then roasting at 120-180 ℃ for 2-3 h.

2. The preparation method according to claim 1, wherein the phyllosilicate is one or more selected from muscovite, sericite, paragonite, phlogopite, biotite, ferrobiotite, lepidolite and vermiculite; preferably, the particle size of the layered silicate is less than 300 mesh.

3. The preparation method according to claim 1, wherein the alkali solution is one or more selected from the group consisting of an aqueous sodium hydroxide solution, an aqueous ammonium bicarbonate solution, and an aqueous ammonia solution; preferably, the concentration of the alkali solution is 10-20%.

4. The production method according to any one of claims 1 to 3, wherein in the step (1), the mass ratio of the layered silicate to the alkali solution is 1: (5-10).

5. The preparation method according to claim 1, wherein the coupling agent is one or more selected from cetyl trimethyl ammonium bromide, 3-aminopropyl triethoxysilane, gamma-glycidoxypropyl trimethoxysilane, and gamma-mercaptopropyl triethoxysilane;

preferably, the coupling agent is added in the form of a coupling agent diluent;

more preferably, in the coupling agent diluent, the ratio by mass of ethanol: water: coupling agent ═ 1: 8: 1.

6. the production method according to claim 1 or 5, wherein in the step (2), the mass ratio of the hydroxyl-activated layered silicate to the coupling agent is 1: (0.5 to 1).

7. The method according to claim 1, wherein the drying is performed at 140 to 160 ℃ in the step (1).

8. A modified layered silicate obtained by the method according to any one of claims 1 to 7.

9. Use of the modified layered silicate of claim 8 for the preparation of concrete; preferably in the preparation of corrosion resistant concrete.

10. A concrete, characterized in that the raw materials comprise: the modified layered silicate of claim 8.

Technical Field

The invention relates to the technical field of building materials and chemical building materials, in particular to modified phyllosilicate and a preparation method and application thereof.

Background

With the development of concrete engineering construction, the application range of concrete is gradually expanded to the environments such as oceans, salt lakes and the like; however, high concentrations of sulfate and chloride ions in the above-described environment can corrode the concrete and thereby affect the durability of the concrete. The main cause of concrete corrosion is the penetration of ions in the water of the external environment. The chloride ions can destroy the passive film of the concrete reinforcing steel bar and accelerate the corrosion of the reinforcing steel bar. Reacting low-concentration chloride ions with a cement hydration product polysulfide type hydrated calcium sulfoaluminate (AFm) to generate a Kuzel salt; the high concentration chloride ion reacts with the AFm to generate Fridel salt, which reduces the yield of hydration products such as ettringite. The sulfate ions react with the hydration product AFm to generate secondary ettringite, the volume of which is doubled, so that expansion damage is caused. Sulfate ions can also react with hydration product calcium hydroxide to generate secondary gypsum, and the volume expansion damage is generated.

At present, the infiltration amount of harmful ions can be greatly reduced by subjecting concrete to hydrophobization treatment. However, the traditional hydrophobization treatment mostly adopts a method of coating waterproof emulsion on the concrete, which not only adds one construction process, but also hardly ensures the durability of the coating waterproof.

In view of this, the invention is particularly proposed.

Disclosure of Invention

The invention aims to provide a preparation method of modified phyllosilicate and the modified phyllosilicate prepared by the method, and the concrete prepared by taking the modified phyllosilicate as a main raw material has good corrosion resistance, and is particularly suitable for severe environments such as oceans, salt lakes and the like; another object of the present invention is to provide the use of the modified layered silicate.

Specifically, the invention provides the following technical scheme:

the invention provides a preparation method of modified phyllosilicate, which comprises the following steps:

(1) taking layered silicate and alkali solution as raw materials, uniformly stirring, and drying to obtain hydroxyl activated layered silicate;

(2) and (3) reacting the hydroxyl activated layered silicate with a coupling agent for 1-2 h, and then roasting at 120-180 ℃ for 2-3 h.

The invention discovers that the layered silicate mineral is of a layered structure, and a micron-sized layered platform-shaped structure can be formed in the process of crushing powder, so that the surface roughness of the layered silicate mineral is increased; furthermore, the invention also discovers that the hydrophobic property of the layered silicate can be further increased by modifying the surface of the layered silicate with a layered platform structure.

In order to further improve the hydrophobicity of the modified phyllosilicate, the preparation method is optimized, and specifically comprises the following steps:

preferably, the phyllosilicate is one or more selected from muscovite, sericite, paragonite, phlogopite, biotite, ferrobiotite, lepidolite and vermiculite; preferably, the particle size of the layered silicate is less than 300 mesh.

Preferably, the alkali solution is one or more selected from sodium hydroxide aqueous solution, ammonium bicarbonate aqueous solution and ammonia aqueous solution; preferably, the concentration of the alkali solution is 10-20%.

In the present invention, the use of the above-mentioned layered silicate and the above-mentioned alkali solution is more advantageous for the preparation of a modified layered silicate having high hydrophobicity.

Preferably, in the step (1), the mass ratio of the layered silicate to the alkali solution is 1: (5-10).

Aiming at the reaction system of the invention, when the mass ratio of the phyllosilicate to the alkali solution is 1: (5-10), the effect is the best.

Preferably, the coupling agent is one or more selected from cetyl trimethyl ammonium bromide, 3-aminopropyl triethoxysilane, gamma-glycidoxypropyl trimethoxysilane and gamma-mercaptopropyl triethoxysilane.

Further, the coupling agent is added in the form of a coupling agent diluent.

Further, in the coupling agent diluent, the ratio by mass of ethanol: water: coupling agent ═ 1: 8: 1.

preferably, in the step (2), the mass ratio of the hydroxyl-activated layered silicate to the coupling agent is 1: (0.5 to 1).

Aiming at the reaction system of the invention, when the mass ratio of the hydroxyl activated layered silicate to the coupling agent is 1: (0.5 to 1), the effect is the best.

Preferably, in the step (1), the drying is performed at 140-160 ℃.

The invention also provides a modified phyllosilicate prepared by the method. When the modified phyllosilicate is used in marine concrete, the sulfate erosion resistance and chloride ion penetration resistance of the concrete are obviously improved, and the durability of the concrete is improved.

The invention also provides the application of the modified phyllosilicate in preparing concrete; preferably in the preparation of corrosion resistant concrete.

The invention also provides concrete which comprises the following raw materials: the modified layered silicate described above.

The concrete provided by the invention can block ions in external water, greatly reduces the corrosion of the concrete, and improves the durability of the concrete on the premise of not influencing the strength and the fluidity of the concrete.

The invention has the beneficial effects that:

(1) when the modified phyllosilicate provided by the invention is used in anti-corrosion concrete, the hydrophobicity of the concrete can be increased, and the corrosion resistance coefficient of the concrete is improved by 16-23%.

(2) The modified phyllosilicate provided by the invention improves the durability aiming at the severe service environment (such as ocean, salt lake and the like) of the concrete under the condition of not influencing the workability and the strength of the concrete.

(3) The modified phyllosilicate provided by the invention adopts organic hydrophobic modification and a micron-level stage structure, can improve the durability of concrete, and provides powerful technical support for ocean engineering.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Example 1

The embodiment provides a modified phyllosilicate (BYC-58), and the preparation method of the modified phyllosilicate (BYC-58) comprises the following steps:

(1) putting 5kg of muscovite (1000 meshes) and 50kg of ammonium bicarbonate aqueous solution (the concentration is 10%) into a reaction kettle, uniformly stirring, and drying at 150 ℃ to obtain hydroxyl activated muscovite;

(2) 9.5kg of hydroxyl-activated muscovite and 5kg of gamma-mercaptopropyltriethoxysilane ethanol aqueous solution (the concentration is 10%) are added into a reaction kettle to react for 1 hour, and the mixture is roasted for 2 hours at the temperature of 120 ℃ to obtain the modified layered silicate (BYC-58).

Example 2

This example provides a modified phyllosilicate (JYN-55), and the preparation method of the modified phyllosilicate (JYN-55) includes the following steps:

(1) 5kg of phlogopite (1000 meshes) and 25kg of ammonia water solution (the concentration is 20%) are put into a reaction kettle, and after uniform stirring, the mixture is dried at 150 ℃ to obtain hydroxyl activated phlogopite;

(2) 9.5kg of the hydroxyl-activated phlogopite and 5kg of a 3-aminopropyltriethoxysilane ethanol aqueous solution (the concentration is 10%) are added into a reaction kettle to react for 1 hour, and the mixture is roasted for 3 hours at 120 ℃ to obtain modified layered silicate (JYN-55).

Example 3

This example provides a modified layered silicate (ZSH-57), which was prepared by a method comprising the steps of:

(1) 5kg of vermiculite (1000 meshes) and 50kg of sodium hydroxide aqueous solution (the concentration is 10%) are put into a reaction kettle, and after being uniformly stirred, the hydroxyl-activated vermiculite is obtained by drying at 150 ℃;

(2) 9.5kg of hydroxyl-activated vermiculite and 5kg of gamma-glycidoxypropyltrimethoxysilane ethanol aqueous solution (the concentration is 10%) are added into a reaction kettle, reacted for 1 hour and roasted at 150 ℃ for 3 hours to obtain the modified layered silicate (ZSH-57).

Test example 1 Corrosion-resistant concrete Performance test

In this test example, concrete was prepared from the modified phyllosilicates of examples 1 to 3 as a main raw material, and the concrete was denoted as concrete 1, concrete 2, and concrete 3, and the three types of concrete were subjected to performance tests, specifically as follows:

the raw materials of the concrete are as follows:

P.I 42.5 cement, river sand fineness modulus of 2.8, limestone aggregate (two-stage grading of 5-10 mm and 10-20 mm), polycarboxylate superplasticizer, modified phyllosilicate BYC-58, JYN-55 and ZSH-57 of examples 1-3.

The raw material formulation of the concrete is shown in table 1.

TABLE 1 raw material mixing ratio (kg/m) of concrete³)

Cement	Sand	Small stone	Big stone	Water (W)	Water reducing agent	Modified layered silicate
							420	745	447	670	168	2.8	15

Concrete 1 (the raw material comprises the modified phyllosilicate BYC-58 in the example 1), concrete 2 (the raw material comprises the modified phyllosilicate JYN-55 in the example 2) and concrete 3 (the raw material comprises the modified phyllosilicate ZSH-57 in the example 3) are respectively prepared according to the raw material formula, and the sulfate attack resistance coefficient of the concrete after 120 times of dry and wet cycles is tested according to GB50082-2016, and the results are shown in Table 2;

TABLE 2 application effect of air entraining agent in various concretes under different air pressures

As shown in Table 2, the concrete containing the modified phyllosilicates of examples 1 to 3 has improved corrosion resistance (16 to 23% higher) without affecting the fluidity and strength.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.