1. A silane waterproof material for concrete protection is characterized by comprising the following specific components: 40-80 parts of alkane silane; 10-50 parts of silane oligomer; 2-12 parts of an aminosilane coupling agent; 0.1-0.3 part of defoaming agent; 0.1-1 part of antioxidant; 0.1-0.5 part of preservative.

2. The silane waterproof material for concrete protection according to claim 1, wherein the alkylsilane is one or a combination of isobutyltriethoxysilane, n-octyltriethoxysilane, isooctyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, hexadecyltriethoxysilane, perfluorohexylethyltriethoxysilane.

3. The silane waterproof material for concrete protection as claimed in claim 1, wherein the silane oligomer is prepared by esterification reaction of bifunctional organic silanol and bifunctional aliphatic alcohol under the action of an acid catalyst at 40-70 ℃ for 1-2 h, and the degree of polymerization is less than or equal to 600; wherein the difunctional organic silanol is one or a combination of diphenyl silanediol, dipropylene silanediol, dimethyl silanediol and methyl phenyl silanediol, and the difunctional alcohol is one or a combination of ethylene glycol, butanediol, hexanediol, polyether diol and polyester diol.

4. The silane waterproof material for concrete protection according to claim 1, wherein the aminosilane coupling agent is one or a combination of gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, gamma-aminoethylaminopropyltrimethoxysilane and N-phenylaminomethyl triethoxysilane.

5. The silane waterproof material for concrete protection according to claim 1, wherein the defoaming agent is one or a combination of silicone emulsion, higher alcohol fatty acid ester complex, polyoxyethylene polyoxypropylene pentaerythritol ether and polyoxypropylene glycerol ether.

6. The silane waterproof material for concrete protection according to claim 1, wherein the antioxidant is one or a combination of 2, 6-di-tert-butyl-p-cresol, pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and phosphite.

7. The silane waterproof material for concrete protection according to claim 1, wherein the preservative is one or a combination of sodium benzoate, nitrite and modified silicone emulsion preservative.

8. The method for preparing a silane water-proofing material for concrete protection according to any one of claims 1 to 7, comprising the steps of:

(1) respectively weighing the alkane silane, the silane oligomer, the aminosilane coupling agent, the defoaming agent, the antioxidant and the preservative according to the parts by weight;

(2) firstly, pouring the weighed alkane silane, silane oligomer and aminosilane coupling agent into a stirring container, and mixing and stirring in an electric stirrer; then mixing the defoaming agent, the antioxidant and the preservative, pouring the mixture into a stirring container, and continuously mixing and stirring;

(3) pouring out the mixture, and standing to obtain the silane waterproof material for concrete protection.

Background

Concrete is a porous material, has certain permeability, and has obvious performance degradation, such as sand formation, salt freezing, shedding and the like, under the action of harmful ions, such as carbon dioxide, water, chloride ions, sulfate and the like in air, and the durability and the service life of the concrete are seriously affected by the problems. Particularly, for some reinforced concrete, because the concrete has hydrophilicity, the steel bars can be gradually dull and rusted under the combined action of oxygen and moisture for a long time, and when the rust expansion stress of the steel bars is greater than the cohesive force of the concrete, the concrete can be cracked and the steel bars can be rusted, so that the instability of the concrete structure is caused, and the safety of the concrete structure is seriously threatened.

Silane waterproof material has obtained quick development in the concrete protection field as a novel hydrophobic ventilative material, and its excellent performances such as anti-soil, alkali-resisting, waterproof have gradually gained people's favor. At present, silane materials are widely applied to various concrete structures at home and abroad, and concrete structures such as Qingdao gulf bridges, Funing highways and the like are protected by the silane materials. The silane impregnation technology is successively incorporated into the specifications of anti-corrosion technical specification of road engineering concrete structures, durability design specification of railway concrete structures and the like in China, and silane materials are incorporated into the standards of mortar and concrete waterproofing agents in 2008. A large number of engineering practices show that the silane material has excellent weather resistance in the concrete protection process, and can effectively protect the concrete structure for a long time.

However, most of the silane waterproof materials adopt an isobutyl or isooctyl triethoxy silane system, and the problems of poor adhesion with a matrix and high volatility exist in the concrete protection process; german Wacker chemical experiments show that in a wind speed environment of 5m/s, the volatilization loss of the isobutyl triethoxysilane after spraying can reach more than 90%, and the volatilization loss of the isooctyl triethoxysilane after spraying can also reach more than 33%. And because the influence of dust in open air environment and the air still can lead to the protective effect to lose efficacy gradually, be difficult to carry out long-term protection to the concrete. In addition, if the surface layer of the pavement concrete and the capillary holes of the shallow layer are penetrated by a trace amount of liquid water, the pavement concrete can be damaged and peeled off in the processes of icing pressure and freeze-thaw cycle, so that the waterproof layer fails and the pavement protection life is reduced. Laboratory and field use experience of more than 10 years in China shows that only micromolecule short-chain isobutyl triethoxysilane is used as a waterproof material, the hydrophobicity and freeze-thaw resistance durability are insufficient, and the phenomena of surface layer sand formation and peeling of concrete can occur.

With the development of technology, solvent type, emulsion type and paste type silane waterproof materials gradually appear, for example, patent CN103923561A discloses a concrete protective agent prepared from alkylalkoxysilane, endgroup polydimethylsiloxane, organic solvent and catalyst and a manufacturing method thereof, but the method takes the organic solvent as a disperse phase, increases the volatility of the whole product, and reduces the environmental protection property of the product. Patent CN108070258A discloses a high-permeability water-in-oil low-surface-energy alkyl siloxane oligomer emulsion prepared from oligosiloxane and amino alkyl copolymerized siloxane and a preparation method thereof, wherein the polymer of siloxane oligomer is regulated and controlled to effectively control the volatility of the system and improve the durability of the system. Patent CN107556050A discloses a silane paste impregnation liquid prepared from difunctional alkylalkoxysilane, cyclic siloxane, trifunctional alkylalkoxysilane and siloxane oligomer, but the silane paste prepared by this method has high viscosity, poor permeability, and a protective effect on the concrete surface, but has poor durability. The silane paste disclosed in patent CNl04926366A and the preparation method thereof are complex, heating is required in the production process, energy consumption is inevitably increased by industrial popularization and application, and the silane paste has poor permeability due to large viscosity. Patent CN101367670A discloses a preparation method of a silane paste protective agent, but a large amount of emulsifier is used in the preparation process, so that the protective performance is reduced. Patent CN102676058A discloses a water-dispersible oligomeric siloxane paste prepared from an alkane-based siloxane oligomer, functional amino polysiloxane, a penetrating agent, an emulsifier and deionized water, which also belongs to a paste protective product and has poor permeability for high-grade concrete.

In conclusion, the concrete protective agent mostly uses water as a solvent at present, and is added with an emulsifier to finally form silane emulsion or paste; the silane emulsion or the silane paste serving as a protective material has high viscosity, is difficult to permeate into the concrete, or only forms a protective effect on the surface of the concrete, and the durability of the silane emulsion or the silane paste is seriously reduced. Therefore, most of silane waterproof materials in the market at present are mainly solvent-based, the viscosity of a waterproof material system is reduced by adding a solvent, the construction performance and the permeability of the waterproof material system are improved, but the existence of the solvent can increase the volatility of the product and easily cause environmental pollution.

Based on the problems, the invention takes the alkane silane, the silane oligomer and the aminosilane coupling agent as main agents to prepare a novel silane waterproof material which has no solvent, low volatilization, high permeability and good durability, so as to improve the freeze-thaw resistance, the sand resistance and the durability of the concrete pavement, prolong the service life of the concrete and reduce the maintenance times and the cost in the whole life cycle.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a silane waterproof material for concrete protection and a preparation method thereof. The silane oligomer is used for replacing the traditional volatile and non-environment-friendly solvent, and the alkane silane, the aminosilane coupling agent, the defoaming agent, the antioxidant and the preservative are matched, so that the ultralow surface energy, the high interface wettability and the migration anticorrosion characteristics of the silane oligomer are realized, and the problems of high volatility, poor permeability, insufficient durability and the like of the traditional silane waterproof material are solved. In addition, the preparation process has the advantages of easily available raw materials, simple method and simple and convenient operation, and has very important significance for expanding the practical application of the silane waterproof material.

The silane waterproof material consists of the following parts: 40-80 parts of alkane silane; 10-50 parts of silane oligomer; 2-12 parts of an aminosilane coupling agent; 0.1-0.3 part of defoaming agent; 0.1-1 part of antioxidant; 0.1-0.5 part of preservative.

The branched chain and the ethoxy in the structure of the alkane silane have relatively stable characteristics, and the branched chain structure can better withstand ultraviolet rays. In addition, after the coating is coated on the base material, the product can gradually permeate into the base material; meanwhile, alkoxy in a molecular chain can be hydrolyzed and condensed to form a net-shaped film along with the accumulation of time, and a water repellent layer is formed, so that the protection effect is achieved. Preferably, the silane coupling agent is one or a combination of n-octyl triethoxysilane, isooctyl triethoxysilane, decyl triethoxysilane, dodecyl triethoxysilane, hexadecyl triethoxysilane and perfluorohexylethyl triethoxysilane. However, the shorter the molecular chain of the alkanesilane is, the more volatile the alkanesilane is and the less protective effect is, and more preferably, it is one or a combination of decyltriethoxysilane, dodecyltriethoxysilane, hexadecyltriethoxysilane and perfluorohexylethyltriethoxysilane.

Most of silane waterproof materials in the market contain solvents such as D40 and ethanol, and the volatility of the solvents increases the overall volatility of the silane waterproof materials. The silane oligomer is also partially added, but the problem of poor oligomer permeability often results in poor overall protective effect. Based on the method, the silane oligomer is prepared by esterification reaction of bifunctional organic silanol and bifunctional fatty alcohol at the reaction temperature of 40-70 ℃ for 1-2 h under the action of an acid catalyst, and the polymerization degree of the silane oligomer is less than or equal to 600; the silane oligomer can not be broken in a natural state, when the silane oligomer contacts concrete, the alkaline environment and the internal moisture of the concrete can cause the hydrolysis and chain breaking of Si-O-C bonds of the concrete, the silane oligomer with the polymerization degree less than or equal to 10 is prone to being formed, and the integral permeability and the protection effect of a system are further improved. The preferred difunctional organic silanol is one or the combination of diphenyl silanediol, dipropylene silanediol, dimethyl silanediol and methyl phenyl silanediol, the preferred difunctional alcohol is one or the combination of ethylene glycol, butanediol, hexanediol, polyether diol and polyester diol, and the more preferred is dipropylene silanediol and hexanediol. The silane oligomer is schematically represented by the following structural formula:

molecular structural formula of silane oligomer

The amino silane coupling agent can penetrate through the cementing surface, penetrate into the concrete and chemically react with air exposed in the environment and water molecules in the substrate to form a water repellent treatment layer, so that the water is inhibited from entering, and the protective service life of the concrete is prolonged. In addition, the amino group in the coupling agent also has certain migration anticorrosion property, further permeates to the bottom of the concrete matrix through the polarity of silane molecules and the gaps of the concrete, and is bonded with the metal surface of the internal framework of the concrete to form a passivation layer, so that the corrosion-resistant anticorrosion function is realized. Preferably one or a combination of gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, gamma-aminoethylaminopropyltrimethoxysilane and N-phenylaminomethyltriethoxysilane. Further, one or a combination of gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane and gamma-aminoethylaminopropyltrimethoxysilane is preferable in view of the viscosity of the system and the anticorrosive effect.

The defoaming agent can reduce bubbles generated in the stirring process, and is preferably one or a combination of emulsified silicone oil, a higher alcohol fatty acid ester compound, polyoxyethylene polyoxypropylene pentaerythritol ether and polyoxypropylene glycerol ether. In consideration of the defoaming effect and the material permeability, one or a combination of polyoxyethylene polyoxypropylene pentaerythritol ether and polyoxypropylene glycerol ether is more preferable.

The antioxidant can prolong the service life of the silane waterproof material and prevent the material from being oxidized to a certain extent, preferably one or a combination of 2, 6-di-tert-butyl-p-cresol, tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester (antioxidant 1010) and phosphite ester, and further preferably a composite antioxidant consisting of phenol hindered phenol antioxidant 1010 and phosphite ester, wherein the ratio of the phenol hindered phenol antioxidant 1010 to the phosphite ester is 1: 1.

The preservative can improve the corrosion resistance of the siloxane-based material to a certain extent, and simultaneously reduces the corrosion to the reinforcing steel bar structure in the concrete, and is preferably one or a combination of sodium benzoate, nitrite and a modified organic silicon emulsion preservative. However, sodium benzoate is not preferable in concrete preservation, and is preferably one or a combination of nitrite and a modified silicone emulsion preservative.

The preparation method comprises the following steps:

(1) respectively weighing the alkane silane, the silane oligomer, the aminosilane coupling agent, the defoaming agent, the antioxidant and the preservative according to the parts by weight;

(2) firstly, pouring the weighed alkane silane, silane oligomer and aminosilane coupling agent into a stirring container, and mixing and stirring in an electric stirrer; then mixing the defoaming agent, the antioxidant and the preservative, pouring the mixture into a stirring container, and continuously mixing and stirring;

(3) pouring out the mixture, and standing to obtain the silane waterproof material for concrete protection.

The beneficial results of the invention are:

(1) the volatilization rate is low: the material volatility is less than or equal to 5 percent, and the content of the silane compound is more than or equal to 99 percent;

(2) strong permeability: the penetration depth of the concrete below C40 is more than or equal to 6mm, and the penetration depth of the concrete between C40 and C50 is more than or equal to 4 mm;

(3) the protective performance is good: the water absorption of the concrete is less than or equal to 5 percent, the chloride absorption reduction effect is more than or equal to 90 percent, and the salt freezing resistance improvement frequency is more than or equal to 25 times;

(4) the silane waterproof material has the advantages of long protection life, common raw materials for preparation, low cost, simple and convenient method and smaller construction difficulty coefficient.

Detailed Description

The present invention will be further described with reference to the following examples.

The starting materials used in the examples are commercially available, and the experimental procedures are conventional unless otherwise specified.

Example 1

Decyl triethoxysilane, silane oligomer, gamma-aminopropyl trimethoxysilane, a polyoxypropylene glyceryl ether antifoaming agent, an antioxidant (phenol hindered phenol antioxidant 1010 and phosphite are compounded in a mass ratio of 1: 1), and a nitrite preservative in a mass ratio of 60: 32: 8: 0.1: 0.1: 0.2 was weighed. Firstly, decyl triethoxysilane, silane oligomer and gamma-aminopropyl triethoxysilane are poured into a stirring container, mixed and stirred in an electric stirrer, and then the mixture of the defoaming agent, the antioxidant and the preservative is poured into the container and continuously stirred, so that the silane waterproof material is obtained.

The specific silane waterproof material has the following properties:

example 2

Dodecyl triethoxysilane, silane oligomer, gamma-aminopropyl triethoxysilane, polyoxyethylene polyoxypropylene pentaerythritol ether defoamer, an antioxidant (phenol hindered phenol antioxidant 1010 and phosphite are compounded according to the mass ratio of 1: 1), and a nitrite preservative according to the mass ratio of 60: 30: 10: 0.1: 0.1: 0.2 was weighed. Firstly, the dodecyl triethoxysilane, the silane oligomer and the gamma-aminopropyl triethoxysilane are poured into a stirring container, mixed and stirred in an electric stirrer, and then the mixture of the defoaming agent, the antioxidant and the preservative is poured into the stirring container and continuously stirred, so that the silane waterproof material is obtained.

The specific silane waterproof material has the following properties:

example 3

Hexadecyl triethoxysilane, silane oligomer, gamma-aminopropyl trimethoxysilane, polyoxyethylene polyoxypropylene pentaerythritol ether defoamer, an antioxidant (phenol hindered phenol antioxidant 1010 and phosphite ester are compounded according to the mass ratio of 1: 1), and a modified organosilicon emulsion preservative according to the mass ratio of 70: 20: 10: 0.1: 0.1: 0.2 was weighed. Firstly, the dodecyl triethoxysilane, the silane oligomer and the gamma-aminopropyl trimethoxysilane are poured into a stirring container, mixed and stirred in an electric stirrer, and then the mixture of the antifoaming agent, the antioxidant and the preservative is poured into the stirring container and continuously stirred, so that the silane waterproof material is obtained.

The specific silane waterproof material has the following properties:

example 4

Decyl triethoxysilane, dodecyl triethoxysilane, silane oligomer, gamma-aminopropyl trimethoxysilane, polyoxyethylene glyceryl ether defoamer, antioxidant (phenol hindered phenol antioxidant 1010 and phosphite are compounded in a mass ratio of 1: 1), and nitrite preservative in a mass ratio of 40: 20: 30: 10: 0.1: 0.1: 0.2 was weighed. Firstly, decyl triethoxysilane, dodecyl triethoxysilane, silane oligomer and gamma-aminopropyl triethoxysilane are poured into a stirring container, mixed and stirred in an electric stirrer, and then the mixture of the defoaming agent, the antioxidant and the preservative is poured into the stirring container and continuously stirred, so that the silane waterproof material is obtained.

The specific silane waterproof material has the following properties:

example 5

Dodecyl triethoxysilane, a D40 solvent, gamma-aminopropyl trimethoxysilane, a polyoxyethylene polyoxypropylene pentaerythritol ether defoamer, an antioxidant (phenol hindered phenol antioxidant 1010 and phosphite are compounded according to the mass ratio of 1: 1), and a nitrite preservative according to the mass ratio of 60: 30: 10: 0.1: 0.1: 0.2 was weighed. Firstly, dodecyl triethoxysilane, a D40 solvent and gamma-aminopropyl trimethoxysilane are poured into a stirring container, mixed and stirred in an electric stirrer, and then a mixture of a defoaming agent, an antioxidant and a preservative is poured into the container and continuously stirred, so that the silane waterproof material is obtained.

The specific silane waterproof material has the following properties:

example 6

Silane oligomer, gamma-aminopropyltrimethoxysilane, a high-carbon alcohol fatty acid ester compound defoaming agent, an antioxidant (phenol hindered phenolic antioxidant 1010 and phosphite ester are compounded according to the mass ratio of 1: 1), and a modified organic silicon emulsion preservative according to the mass ratio of 60: 40: 0.1: 0.1: 0.2 was weighed. Firstly, pouring silane oligomer and gamma-aminopropyltrimethoxysilane into a stirring container, mixing and stirring in an electric stirrer, and then pouring the mixture of the defoaming agent, the antioxidant and the preservative into the container and continuously stirring to obtain the silane waterproof material.

The specific silane waterproof material has the following properties:

example 7

Silane oligomer, high-alcohol fatty acid ester compound defoaming agent, antioxidant (phenol hindered phenol antioxidant 1010 and phosphite ester are compounded according to the mass ratio of 1: 1), and modified organic silicon emulsion preservative according to the mass ratio of 100: 0.1: 0.1: 0.2 was weighed. And pouring the silane oligomer, the defoaming agent, the antioxidant and the preservative into the mixture, mixing and stirring to obtain the silane waterproof material.

The specific silane waterproof material has the following properties:

comparing example 2 with example 5, it can be seen that the replacement of silane oligomer by ordinary D40 solvent in example 5 can significantly increase the volatility of the system, and the protective effect (penetration depth, water absorption, salt freezing resistance increase times, chloride absorption reduction effect) of the material is significantly reduced.

Comparing example 3 with example 6, it can be seen that the introduction of the chain alkyl silane in example 3 increases the permeability of the material and enhances the protective effect of the concrete, compared to silane oligomer and aminosilane coupling agent systems, wherein the salt freeze resistance increase times and the chloride absorption reduction effect are both significantly improved.

Comparing example 6 with example 7, it can be seen that silane oligomer alone as a waterproof material can maintain a certain penetration depth of the material by means of the breakage of Si-O-C bond, and has a better protection effect.