阅读说明：本技术 一种混凝土表面硬化剂及其制备方法 (Concrete surface hardening agent and preparation method thereof ) 是由 姚国友 马晔 李春德 金鑫 于 2021-09-15 设计创作，主要内容包括：本发明公开了一种混凝土表面硬化剂及其制备方法,所述混凝土表面硬化剂包括如下组分：改性硅酸锂溶液60-70份、液体表面张力改性剂0.2-0.5份、离子稳定剂0.2-0.5份和水30-40份,其中所述改性硅酸锂溶液包括40-60份硅酸钾溶液,8-12份甲基硅酸钠和8-12份氟硅酸镁。本发明的混凝土表面硬化剂,能够提高混凝土表面密实度和表面强度,能够在混凝土裂缝内部生成壳状结构,达到提高混凝土硬度的效果；本发明的混凝土表面硬化剂具有较强的渗透性能,并且能够在3天内提高表面强度5Mpa以上。(The invention discloses a concrete surface hardening agent and a preparation method thereof, wherein the concrete surface hardening agent comprises the following components: 60-70 parts of modified lithium silicate solution, 0.2-0.5 part of liquid surface tension modifier, 0.2-0.5 part of ion stabilizer and 30-40 parts of water, wherein the modified lithium silicate solution comprises 40-60 parts of potassium silicate solution, 8-12 parts of sodium methyl silicate and 8-12 parts of magnesium fluosilicate. The concrete surface hardening agent can improve the surface compactness and the surface strength of concrete, can generate a shell-shaped structure in a concrete crack and achieves the effect of improving the hardness of the concrete; the concrete surface hardening agent has strong permeability and can improve the surface strength by more than 5Mpa within 3 days.)

1. The concrete surface hardening agent comprises the following components in parts by weight: 60-70 parts of modified lithium silicate solution, 0.2-0.5 part of liquid surface tension modifier, 0.2-0.5 part of ion stabilizer and 30-40 parts of water, wherein the modified lithium silicate solution comprises 40-60 parts of potassium silicate solution, 8-12 parts of sodium methyl silicate and 8-12 parts of magnesium fluosilicate.

2. A concrete surface hardening agent according to claim 1, wherein: the weight ratio of the sodium methyl silicate to the magnesium fluosilicate is 1: 1.

3. A concrete surface hardening agent according to claim 1, wherein: the liquid surface tension modifier is one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, dodecyl trimethyl ammonium chloride (bromide) and dodecyl dimethyl benzyl ammonium chloride.

4. A concrete surface hardening agent according to claim 1, wherein: the ionic stabilizer is one or more of citric acid, tricarballylic acid, butanetetracarboxylic acid, itaconic acid and oligomeric maleic acid.

5. A preparation method of a concrete surface hardening agent comprises the following steps:

s1, weighing 30-40 parts of deionized water, 0.2-0.5 part of liquid surface tension modifier and 0.2-0.5 part of ion stabilizer;

s2, adding the liquid surface tension modifier and the ionic stabilizer into deionized water, and stirring at a low speed;

s3, adding 60-70 parts of modified lithium silicate solution into the liquid of S2, and stirring for 5-30 min.

6. The method for preparing a concrete surface hardening agent according to claim 5, wherein the temperature during the stirring is room temperature in S2.

7. The method for preparing a concrete surface hardening agent according to claim 5, wherein the method for preparing the modified lithium silicate solution in S1 comprises the following steps:

s11, weighing 40-60 parts of potassium silicate solution, 8-12 parts of sodium methyl silicate and 8-12 parts of magnesium fluosilicate;

s12, adding sodium methyl silicate and magnesium fluosilicate into a potassium silicate solution;

s13, heating and stirring until the solution is completely mixed, and standing for later use.

8. The method of claim 7, wherein the sodium methyl silicate and the magnesium silicofluoride are added to the potassium silicate solution at room temperature in S12.

9. The method for preparing a concrete surface hardener as claimed in claim 7, wherein the heating temperature is 40-70 ℃ and the stirring time is 5-30min in S13.

Technical Field

The invention relates to a concrete surface hardening agent, and belongs to the technical field of building material additives.

Background

One of the current common concrete structure's problem is that concrete surface strength is not enough, because cement is storing the proportioning problem of the in-process admixture of transportation environment humidity, impurity in the cement is more or at the concrete mixing leads to the quality of concrete relatively poor, and the concrete of pouring the completion is maintained under abominable environment, leads to the base face to appear the phenomenon that the ash rises, intensity can't satisfy the designing requirement. For some buildings exposed in the corrosion environment containing harmful substances such as acid, alkali, salt and the like all year round, the harmful substances can enter the concrete structure from the fine cracks on the surface of the concrete and generate chemical reaction, so that the alkalinity of the concrete structure is reduced, the protection capability of the steel bars is reduced, and the strength and the service life of the concrete structure are seriously influenced.

Related materials among the prior art are shallow in infiltration depth, generally about 1 ~ 3mm, and the reinforcing effect is not obvious, generally below 3 ~ 5Mpa, is applicable to the project that requires less to the intensity improvement, and is higher or require to improve the great concrete effect of resilience value and can reduce to some improvement intensity to present material can't make the concrete improve intensity rapidly in the short time, can't satisfy the acceptance requirement.

Therefore, a method for reinforcing the surface of concrete or building mortar is urgently needed to solve the above problems.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a concrete surface hardening agent having a good penetration effect and a high rebound value.

In order to achieve the above purpose, one of the technical schemes adopted by the invention is as follows: the concrete surface hardening agent comprises the following components in parts by weight: 60-70 parts of modified lithium silicate solution, 0.2-0.5 part of liquid surface tension modifier, 0.2-0.5 part of ion stabilizer and 30-40 parts of water, wherein the modified lithium silicate solution comprises 40-60 parts of potassium silicate solution, 8-12 parts of sodium methyl silicate and 8-12 parts of magnesium fluosilicate.

Further, the weight ratio of the sodium methyl silicate to the magnesium fluosilicate is 1: 1.

Further, the liquid surface tension modifier is one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, dodecyl trimethyl ammonium chloride (bromide) and dodecyl dimethyl benzyl ammonium chloride.

Further, the ionic stabilizer is one or more of citric acid, tricarballylic acid, butanetetracarboxylic acid, itaconic acid and oligomeric maleic acid.

The invention also provides a preparation method of the concrete surface hardening agent, which comprises the following steps:

s1, weighing 30-40 parts of deionized water, 0.2-0.5 part of liquid surface tension modifier and 0.2-0.5 part of ion stabilizer;

s2, adding the liquid surface tension modifier and the ionic stabilizer into deionized water, and stirring at a low speed;

s3, adding 60-70 parts of modified lithium silicate solution into the liquid of S2, and stirring for 10-30 min.

Further, in S2, the temperature was room temperature during stirring.

Further, the preparation method of the modified lithium silicate solution in S1 comprises the following steps:

s11, weighing 40-60 parts of potassium silicate solution (modulus is 2.2, solid content is 35%), 8-12 parts of sodium methyl silicate and 8-12 parts of magnesium fluosilicate;

s12, adding sodium methyl silicate and magnesium fluosilicate into a potassium silicate solution;

s13, heating and stirring until the solution is completely mixed, and standing for later use.

Further, in S12, sodium methyl silicate and magnesium fluorosilicate were added to the potassium silicate solution at room temperature.

Further, in S13, the heating temperature is 40-70 ℃, and the stirring time is 5-30 min.

The invention has the beneficial effects that:

1) the concrete surface hardening agent can improve the surface compactness and the surface strength of concrete, can generate a shell-shaped structure in a concrete crack, and achieves the effect of improving the hardness of the concrete.

2) The concrete surface hardening agent has stronger permeability, and can improve the surface strength by more than 5Mpa within 3 days, and the lower the original strength of a concrete member is, the larger the amplitude of the concrete surface reinforcing agent can be improved.

Detailed Description

The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention, and to clearly and unequivocally define the scope of the present invention.

Examples

The invention relates to a concrete surface hardening agent, which comprises the following components: the modified lithium silicate solution comprises, by weight, 60-70 parts of modified lithium silicate solution, 0.2-0.5 part of liquid surface tension modifier, 0.2-0.5 part of ion stabilizer and 30-40 parts of water, wherein the modified lithium silicate solution comprises 40-60 parts of potassium silicate solution (modulus is 2.2, solid content is 35%), 8-12 parts of sodium methyl silicate and 8-12 parts of magnesium fluosilicate.

In this example, the weight ratio of the sodium methyl silicate to the magnesium fluorosilicate was 1: 1.

In this embodiment, the liquid surface tension modifier is one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, ammonium dodecyl trimethyl chloride (bromide) and ammonium dodecyl dimethyl benzyl chloride.

In this embodiment, the ionic stabilizer is one or more of citric acid, tricarballylic acid, butanetetracarboxylic acid, itaconic acid, and oligomeric maleic acid.

The preparation method of the concrete surface hardening agent in the embodiment comprises the following steps:

s1, weighing 30-40 parts of deionized water, 0.2-0.5 part of liquid surface tension modifier and 0.2-0.5 part of ion stabilizer;

s2, adding the liquid surface tension modifier and the ionic stabilizer into deionized water, and stirring at low speed at room temperature;

s3, adding 60-70 parts of modified lithium silicate solution into the liquid of S2, and stirring for 10-30 min.

The preparation method of the modified lithium silicate solution in S1 comprises the following steps:

s11, weighing 40-60 parts of potassium silicate solution, 8-12 parts of sodium methyl silicate and 8-12 parts of magnesium fluosilicate;

s12, adding sodium methyl silicate and magnesium fluosilicate into a potassium silicate solution at room temperature;

s13, heating to 40-70 ℃, stirring for 5-30min until the solution is completely mixed, and standing for later use.

Wherein the magnesium fluosilicate is directly purchased, and the manufacturer is Jinanle Heng chemical industry Co.

Compared with the common lithium silicate solution, the modified lithium silicate solution in the embodiment has excellent osmotic crystallization performance and adsorption performance, the surface tension modifier of the liquid can effectively reduce the surface tension of the material, the penetration depth of the modified lithium silicate solution can be improved, the silanol group of the sodium methyl silicate in the modified lithium silicate solution can react with the silanol group of the lithium silicate to be dehydrated and crosslinked, so that the bonding performance of the lithium silicate solution and the inner wall of a concrete crack is improved, the modified lithium silicate solution can be cured on the inner wall of the crack, irregular concrete pores and cracks are repaired to be of a regular structure with a shell structure, when the external pressure is applied to the external environment, the structure can effectively transmit the external force to other parts of the structure, the concentration force is effectively counteracted, and the resilience strength of the surface of the concrete is improved. Because the modified lithium silicate solution can not generate reversible reaction when meeting water again after being cured, the structure can exist in concrete permanently, failure caused by secondary meeting water of the structure can be avoided, and the cured modified lithium silicate solution has a micro-expansion function, can effectively reduce the width of concrete cracks and improves the compactness of the concrete.

The ion stabilizer in the embodiment has a plurality of carboxyl structures, and after the structure permeates into the concrete, the structure can improve the solubility of unhydrated calcium hydroxide crystals in the concrete, and convert the unhydrated calcium hydroxide crystals in the concrete into calcium ions, and because the ionic bond acting force between silicate ions and the carboxyl groups is stronger than the ionic force between the calcium ions and the carboxyl groups, complex ions formed by the carboxyl groups and the calcium ions can be combined with the silicate ions after meeting silicate ions in a solution, and simultaneously ionized calcium ions can be combined with the carboxyl groups in the solution again for repeated circulating reaction, so that the purpose of compacting the concrete structure is realized.

Example 1

S1, preparation of modified lithium silicate solution: weighing 12 parts of methyl sodium silicate and 12 parts of magnesium fluosilicate at room temperature, adding 60 parts of potassium silicate solution, heating to 40-50 ℃, stirring for 5-30min until the solution is completely mixed, and standing for later use.

S2, weighing 40 parts of deionized water, 0.2 part of liquid surface tension modifier and 0.2 part of ion stabilizer;

s3, adding the liquid surface tension modifier and the ionic stabilizer into deionized water, and stirring at low speed at room temperature;

s4, adding 60 parts of the modified lithium silicate solution prepared in the S1 into the liquid of the S3, and stirring for 10min to prepare the concrete surface hardening agent.

Example 2

S1, preparation of modified lithium silicate solution: weighing 10 parts of sodium methyl silicate and 10 parts of magnesium fluosilicate at room temperature, adding 50 parts of potassium silicate solution, heating to 50-60 ℃, stirring for 5-30min until the solution is completely mixed, and standing for later use.

S2, weighing 30 parts of deionized water, 0.2 part of liquid surface tension modifier and 0.2 part of ion stabilizer;

s3, adding the liquid surface tension modifier and the ionic stabilizer into deionized water, and stirring at low speed at room temperature;

s4, adding 70 parts of the modified lithium silicate solution prepared in the S1 into the liquid of the S3, and stirring for 10min to prepare the concrete surface hardening agent.

Example 3

S1, preparation of modified lithium silicate solution: weighing 9 parts of sodium methylsilicate and 9 parts of magnesium fluosilicate at room temperature, adding 45 parts of potassium silicate solution, heating to 60-70 ℃, stirring for 5-30min until the solutions are completely mixed, and standing for later use.

S2, weighing 40 parts of deionized water, 0.5 part of liquid surface tension modifier and 0.5 part of ion stabilizer;

s3, adding the liquid surface tension modifier and the ionic stabilizer into deionized water, and stirring at low speed at room temperature;

s4, adding 60 parts of the modified lithium silicate solution prepared in the S1 into the liquid of the S3, and stirring for 20min to obtain the concrete surface hardening agent.

Example 4

S1, preparation of modified lithium silicate solution: weighing 10 parts of sodium methyl silicate and 10 parts of magnesium fluosilicate at room temperature, adding 50 parts of potassium silicate solution, heating to 60-70 ℃, stirring for 5-30min until the solution is completely mixed, and standing for later use.

S2, weighing 30 parts of deionized water, 0.5 part of liquid surface tension modifier and 0.5 part of ion stabilizer;

s3, adding the liquid surface tension modifier and the ionic stabilizer into deionized water, and stirring at low speed at room temperature;

s4, adding 70 parts of the modified lithium silicate solution prepared in the S1 into the liquid of the S3, and stirring for 30min to prepare the concrete surface hardening agent.

Example 5

Performance test 1: testing the influence of the concrete surface hardening agent on the compressive strength and the flexural strength of the reference concrete:

the test method comprises the following steps:

and S1, pouring 6 blocks of 150-150 concrete test blocks in the same proportion and environment, and curing for 28d under standard conditions.

And S2, taking out the product from the curing box and drying the product after curing.

S3, randomly selecting 3 concrete test blocks, and uniformly coating the concrete surface hardening agent on the surface of the test blocks for 4-5 times.

And S4, curing the blank test block and the test block coated with the concrete surface hardening agent in the air for 36 d.

S5, testing the compressive and flexural strength after the maintenance is finished, and obtaining the following results:

the concrete surface hardening agent influences the results of the standard concrete compressive strength and flexural strength (Table I)

Example 6

Performance test 2: the concrete surface hardener has influence on the impermeability of the reference concrete:

s1, pouring 6 concrete impermeability test blocks with the upper opening diameter of 175mm, the lower opening diameter of 185mm and the height of 150mm in the same proportion and environment, and curing for 28d under standard conditions.

And S2, taking out the product from the curing box and drying the product after curing.

S3, randomly selecting 3 concrete anti-permeability test blocks, and uniformly coating the concrete surface hardening agent on the surface of the concrete anti-permeability test blocks for 4-5 times.

And S4, curing the blank test block and the test block coated with the concrete surface hardening agent in the air for 36 d.

S5, after maintenance, installing the sample on a impermeability instrument to perform impermeability test, and testing the permeability height, wherein the results are as follows:

effect of concrete surface hardening agent on the resistance to Water osmotic pressure of the reference concrete results (Table two)

Example 7

The concrete surface hardener prepared in example 1 was compared to the following three formulations (table three):

table three:

the modified lithium silicate solution is not added in the comparison groups I and III, and is replaced by a lithium silicate solution with the common modulus of 2-8, wherein a lithium silicate solution manufacturer is a Baoding City Runfeng practice Co. And (3) comparing the rebound strength improvement values of 3d after being coated on the same concrete wall surface, wherein the total number of the measuring points is 16, and the unit is megapascal. As shown in table four:

table four:

the above table shows that the modified lithium silicate solution has the greatest influence on the effect of improving the strength rebound value of the concrete, the modified lithium silicate solution is the main component of the reinforcing agent, so that the lack of important reactants can have great influence on the result, the ion stabilizer has the main function of improving the permeability of the material, and the reduction of the permeability of the material directly causes the reduction of the height of the material penetrating into the concrete, thereby influencing the effect of the material.

The concrete hardener prepared in example 1 was subjected to a performance test with reference to JC/T2158-:

table five:

as can be seen from the above table, the hardness and 24h surface water absorption of the concrete base surface constructed by the product far exceed the standard requirements of JC/T2158-.

The above embodiments are merely illustrative of the technical concept and features of the present invention, and the present invention is not limited thereto, and any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of the present invention.