阅读说明：本技术 一种用于填充混凝土结构微孔的纳米复合材料及其制备方法和应用 (Nano composite material for filling concrete structure micropores and preparation method and application thereof ) 是由 祝静 张志乾 魏宏亮 于 2020-05-09 设计创作，主要内容包括：本发明涉及一种用于填充混凝土结构微孔的纳米复合材料及其制备方法和应用,属于混凝土结构性能改进技术领域。本发明制备的纳米水溶液以其超低粘度的高渗透性和高纳米活性,可快速迁移、渗透到混凝土内部,提高混凝土表层到内部的致密性,从而提高混凝土结构的抗渗透性、抗开裂性、表面强度、硬度及综合耐久性,改善混凝土耐酸碱性、耐冻融性、抗滑性能和抗离子侵蚀性等。本发明制备的纳米水溶液,实现可对处于不同服役环境下具有小于0.1mm孔隙的混凝土结构进行修复和养护。(The invention relates to a nano composite material for filling concrete structure micropores and a preparation method and application thereof, belonging to the technical field of concrete structure performance improvement. The nano water solution prepared by the invention can be rapidly transferred and permeated into concrete by virtue of the ultra-low viscosity, high permeability and high nano activity of the nano water solution, and the compactness from the surface layer of the concrete to the inside is improved, so that the permeability resistance, the cracking resistance, the surface strength, the hardness and the comprehensive durability of a concrete structure are improved, and the acid and alkali resistance, the freeze-thaw resistance, the skid resistance, the ion erosion resistance and the like of the concrete are improved. The nano water solution prepared by the invention can repair and maintain concrete structures with pores smaller than 0.1mm in different service environments.)

1. A nanocomposite for filling micropores of a concrete structure, comprising: the raw materials of the nano composite material comprise sodium silicate nano solution, surfactant, curing agent, coagulant, MDT organic ester and water; the total mass of the raw materials of the nano composite material is 100%, and the mass percentage of the components is as follows:

the surfactant is at least one of sodium dodecyl benzene sulfonate, sodium lauryl sulfate and sodium stearate;

the curing agent is at least one of sodium fluosilicate, aluminum tripolyphosphate and potassium fluosilicate;

the coagulant is one or a mixture of two of ethyl acetate and triethanolamine.

2. A nanocomposite for filling the pores of a concrete structure according to claim 1, characterized in that: the grain diameter of the sodium silicate in the sodium silicate nanometer solution is less than 800 nm.

3. A nanocomposite for filling the pores of a concrete structure according to claim 1, characterized in that: the viscosity of the sodium silicate nano solution is less than 100 centipoises.

4. A nanocomposite for filling the pores of a concrete structure according to claim 1, characterized in that: the Baume degree of the sodium silicate nano solution is 35-48 degrees at 20 ℃.

5. A nanocomposite for filling the pores of a concrete structure according to claim 1, characterized in that: the modulus of the sodium silicate nano solution is 3.2-3.8.

6. A method for preparing the nanocomposite for filling the pores of the concrete structure according to claim 1, wherein: the method comprises the following steps:

(1) mixing sodium silicate, a surfactant and deionized water, and stirring to obtain a mixture;

(2) and (2) adding a curing agent, a coagulant and MDT organic ester into the mixture obtained in the step (1), stirring, and filtering to remove impurities to obtain the nano composite material.

7. The method for preparing a nanocomposite for filling micropores of a concrete structure according to claim 6, wherein: in the step (1), the stirring time is 10-15 min.

8. The method for preparing a nanocomposite for filling micropores of a concrete structure according to claim 6, wherein: in the step (2), the stirring time is 20-30 min.

9. Use of the nanocomposite material according to claim 1 for filling the pores of a concrete structure, characterized by the steps of:

(1) firstly, cleaning the surface of a concrete structure to be repaired;

(2) the nano composite material is constructed on the surface of the concrete structure by adopting coating, roller, spraying equipment or spraying equipment, and when the nano water solution completely permeates into the concrete structure, one-time construction is completed, wherein the construction is carried out for 2-3 times, and the construction interval is 20-30min each time.

10. Use of a nanocomposite material according to claim 9 for filling pores of a concrete structure, characterized in that: the concrete structure is a dam, a port, a bridge, a tunnel, a sewage pool or an underground garage.

Technical Field

The invention relates to a nano composite material for filling concrete structure micropores, a preparation method and application thereof, belonging to the technical field of concrete structure performance improvement, wherein the micropores refer to the pore diameter of less than 0.1 mm.

Background

Concrete structures have become the most widely used building structure form in the world, and a large number of building constructions require that the concrete structures must ensure the durability within the service period so as to avoid energy consumption and environmental problems caused by repeated construction. Therefore, the safety and durability of the concrete structure within the designed service life are ensured, and the service life of the structure is prolonged, which becomes a problem of important attention in academic and engineering circles.

It is generally believed that the durability of a concrete structure is closely related to its permeability, with the denser the concrete, the less permeable and the better the durability. The traditional repairing material such as the waterproof coiled material can only protect the concrete surface, has a certain repairing effect, and the surface layer material is easy to fall off or age along with the lapse of time, so that the effect is poor. Therefore, a great deal of work is carried out on the problems of repairing and blocking concrete pores and improving the compactness of concrete. An effective method for improving the compactness of concrete by adding waterproof additives and the like in the preparation process of concrete, for example, in the technology disclosed in patent CN104628354A, a repairing material with strong permeability and high-efficiency bonding performance is developed by utilizing the stacking advantages of nano materials and polymers, and the repairing material is added in the preparation process of concrete and has the effect of improving the compactness and the mechanical property of the concrete. However, the preparation process of the material is complicated, the components contain 10-15% of polymer, the cost is high, the material needs to be mixed in cement mortar for use, and a large amount of existing concrete buildings cannot be repaired. In the prior art, patents CN101619203A, CN101671154A, CN102226073A and CN105503262A disclose a kind of water-based permeable crystalline waterproof material technology with permeability respectively, which can permeate into capillary pores or other fine pores within a certain depth range of a concrete surface layer by spraying or coating on the concrete surface, and rapidly react with internal free calcium ions to generate C-S-H crystals, thereby improving the compactness and durability of concrete. However, the material technology cannot effectively control the amount of generated C-S-H crystals and the position of filling the pores in the concrete in the application process, so that the problem of unstable concrete repairing effect exists. In order to solve the problem, patent CN106904928A discloses a reaction-rate-controllable water-based permeable crystallization type waterproof material technology, which realizes the control of the number and position of C-S-H crystals by controlling the reaction rate of the material and the internal free calcium ions, so as to achieve a stable concrete repairing effect. However, the penetration depth of the material technology in concrete is only 14-16mm, so that the material technology only has effective repairing effect on the concrete surface layer, and is difficult to repair the internal structure damage of the concrete.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a nano aqueous solution which has strong permeability in concrete, can repair and maintain concrete structures with pores smaller than 0.1mm in different service environments, and has the effect of remarkably improving the durability of the concrete structures.

The purpose of the invention is realized by the following technical scheme.

A nanocomposite for filling micropores of a concrete structure, the raw material of the nanocomposite comprising a sodium silicate nano solution (sodium silicate having a particle size of less than 800nm), a surfactant, a curing agent, a coagulant, MDT organic ester and water; the total mass of the raw materials of the nano composite material is 100%, and the mass percentage of the components is as follows:

the sodium silicate nano solution has the effects of reacting with free calcium ions in the concrete to generate C-S-H crystals and filling cracks and pores in the concrete to achieve the gel waterproof effect, the viscosity of the sodium silicate nano solution is less than 100 centipoises, the baume degree at 20 ℃ is 35-48 degrees, and the modulus is 3.2-3.8;

the surfactant has the functions of preventing sodium silicate from agglomerating and improving the permeability of the nano water solution in the concrete, and is at least one of sodium dodecyl benzene sulfonate, sodium lauryl sulfate and sodium stearate;

the curing agent has the function of promoting the reaction of sodium silicate and free calcium ions in the concrete, and is at least one of sodium fluosilicate, aluminum tripolyphosphate and potassium fluosilicate;

the coagulant is used for promoting the unhydrated cement material in the non-concrete to further carry out hydration reaction, increasing the calcium ion concentration in pores in the concrete and promoting the reaction of sodium silicate and calcium ions, and is one or a mixture of ethyl acetate and triethanolamine;

the MDT organic ester has the characteristics of self-hardening, no toxicity and no pollution, and has the function of further permeating silicate in the concrete to react to generate silicic acid, and the silicic acid is interconnected to form a net-shaped framework structure, so that the internal strength and the compactness of the concrete are improved.

A method for preparing a nanocomposite for filling micropores of a concrete structure, the method comprising the steps of:

(1) mixing sodium silicate, surfactant and deionized water, and stirring for 10-15min to obtain a mixture;

(2) and (2) adding a curing agent, a coagulant and MDT organic ester into the mixture obtained in the step (1), stirring for 20-30min, and filtering to remove impurities to obtain the nano composite material.

Use of a nanocomposite for filling the pores of a concrete structure, the steps comprising:

(1) firstly, cleaning the surface of a concrete structure to be repaired, removing impurities such as oil stains, dust and the like on the surface, and keeping the surface of the concrete structure dry;

(2) the construction is carried out by adopting a brush, a roller, spraying equipment or spraying equipment, the nano composite material is constructed on the surface of the concrete structure, the permeation condition of the nano aqueous solution is observed, when the nano aqueous solution completely permeates into the concrete structure, the construction is completed once, usually 2-3 times, and the construction interval is 20-30min each time.

The nano composite material is suitable for wide building structure forms of concrete structures, and is particularly suitable for early maintenance, deterioration repair, waterproof protection and the like of the concrete structures of municipal engineering concrete buildings such as dams, ports, bridges, tunnels, sewage pools, underground garages and the like.

Compared with the prior art, the invention has the following beneficial effects:

(1) the nano water solution prepared by the invention can be rapidly transferred and permeated into concrete by virtue of the ultra-low viscosity, high permeability and high nano activity of the nano water solution, and the compactness from the surface layer of the concrete to the inside is improved, so that the permeability resistance, the cracking resistance, the surface strength, the hardness and the comprehensive durability of a concrete structure are improved, and the acid and alkali resistance, the freeze-thaw resistance, the skid resistance, the ion erosion resistance and the like of the concrete are improved.

(2) The nano water solution prepared by the invention can repair and maintain concrete structures with pores smaller than 0.1mm in different service environments.

(3) The nano solution prepared by the invention has the advantages of simple preparation method, low cost, no pollution, convenient construction and no need of special maintenance after construction.

(4) The nano composite material can obviously prolong the service life of a concrete structure and greatly reduce the maintenance cost of the concrete structure in the field of buildings in China.

Detailed Description

For a further understanding of the invention, preferred embodiments of the invention are described below in conjunction with the specific embodiments, but these descriptions are intended to further illustrate the features and advantages of the invention and not to limit the claims of the invention.