A water-based material for beautifying and protecting fair-faced concrete and its application

Abstract

This invention relates to a water-based material for the beautification and protection of fair-faced concrete and its application. The water-based material for the beautification and protection of fair-faced concrete comprises powder and emulsion. The powder includes cement, sand powder, mineral powder, dispersing and suspending agents, titanium dioxide, and fly ash; the emulsion includes a polymer emulsion, defoamer, water-reducing agent, and water. The water-based material provided by this invention significantly improves the adhesion between the beautification and protection material and the fair-faced concrete interface, with a bond strength greater than 2.5 MPa after 28 days. It exhibits good impermeability and freeze-thaw resistance, with a secondary impermeability pressure exceeding 0.6 MPa and no cracking or peeling after 150 freeze-thaw cycles. It improves the pore structure and density of the beautification material, enhancing its strength and quality, making its appearance more aesthetically pleasing and robust, and effectively preventing the erosion of moisture and harmful substances.

Description

Technical Field

[0001] This invention relates to a water-based material for the beautification and protection of fair-faced concrete and its application, belonging to the field of concrete material additive technology. Background Technology

[0002] Due to factors such as raw materials and surface micro-cracks, the appearance of fair-faced concrete is often not very good after casting. Differences in the origin, color, and gradation of raw materials, as well as construction factors, result in poor appearance quality of fair-faced concrete, with defects such as color difference and holes. After casting, the surface and interior of fair-faced concrete develop many micro-cracks due to water loss, providing channels for external deterioration factors such as rainwater, carbon dioxide, and acidic substances, leading to carbonation, freeze-thaw damage, and poor durability.

[0003] In response to the above situation, the currently widely used beautifying and protective materials for fair-faced concrete are mostly organic materials based on acrylic resin, silicone resin, and fluorocarbon polymers. These materials are flammable, odorous, and toxic, and pollute the environment during construction. After application, these materials form a non-porous, airtight coating on the concrete surface, inhibiting the diffusion of harmful moisture from the concrete. When the expansion force of moisture accumulation at the interface exceeds the adhesion force, the coating is prone to blistering and cracking. Furthermore, because the comprehensive mechanical properties of this coating do not match those of concrete (modulus, Poisson's ratio, aging performance, etc.), the coating will show signs of aging, peeling, and flaking after 1-3 years of use, damaging the concrete itself and failing to maintain its beautifying and protective effect for a long time. Therefore, developing a water-based inorganic material that is odorless, non-toxic, environmentally friendly to construction and personnel, has the same comprehensive mechanical properties as the concrete itself, can form a one-way breathable beautifying and protective layer, and has good durability is of great significance.

[0004] Patent application ZL 201910146232.0 discloses a nano-modified silicate penetrating crystallizing material and its application method. The active ingredient of this material can penetrate into the concrete and react with calcium ions to form CSH crystals, which fill the pores or capillary pores inside the concrete, thereby improving the surface density and overall durability of the concrete. However, this material has no beautification or protection effect on the concrete surface and needs to be used in conjunction with a fair-faced concrete beautification and protection material. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] In order to solve the above-mentioned problems of the prior art, the present invention provides a water-based inorganic concrete beautification and protection material and its application method, which solves the problems of current fair-faced concrete beautification and protection materials being prone to cracking, aging, peeling and falling off, and unable to maintain the beautification and protection of fair-faced concrete for a long time.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0009] A water-based material for the beautification and protection of fair-faced concrete, comprising the following components by weight:

[0010] Powder: 40-55 parts cement, 5-15 parts sand powder, 5-15 parts mineral powder, 1-3 parts dispersing and suspending agent, 3-5 parts titanium dioxide and 5-15 parts fly ash;

[0011] Emulsion: 45-55 parts of polymer emulsion, 1-5 parts of defoamer, 0.5-1.5 parts of water-reducing agent, and 30-40 parts of water.

[0012] As described above, the water-based material preferably includes one, two, or more of the following: silicate cement, aluminate or ferroaluminate cement, sulfate cement, and white cement.

[0013] More preferably, the cement comprises 40 parts silicate cement, 13 parts aluminoferrite cement and 2 parts white cement.

[0014] In the aqueous material described above, preferably, the dispersant / suspending agent is a powder, and is one or more of the sulfonate compounds in copolymers of polyepoxyalkylene chains, lignin sulfonates, and naphthalene sulfonate formaldehyde condensates.

[0015] In the water-based material described above, preferably, the sand powder has a mesh size of 100 to 120 mesh.

[0016] In the water-based material described above, preferably, the mineral powder is of grade S95.

[0017] As described above, the water-based material preferably has a fly ash with a specific surface area ≥ 500 m². 2 / kg.

[0018] In the aqueous material described above, preferably, the polymer emulsion is one, two, or more of the following: styrene-acrylic emulsion, vinyl acetate copolymer emulsion, silicone-acrylic emulsion, or acrylic emulsion.

[0019] In the water-based materials described above, preferably, the defoamer is one or more of emulsified silicone, polysiloxane, and water-based silicone defoamers;

[0020] In the water-based materials described above, preferably, the water-reducing agent is one or more of the following: modified polymer sulfonic acid, high molecular weight polymer viscosity modifier, and sulfonated melamine water-reducing agent.

[0021] As described above, preferably, the powder and emulsion are directly mixed during preparation or use. When using, the powder should be poured into a container first, and then the emulsion should be poured into the container according to the recommended ratio. Then, an electric mixer (550 rpm) should be used to stir for 1 to 2 minutes, and the mixture should be used up on the same day.

[0022] The water-based material described above is preferably used by mixing the powder and emulsion evenly at a weight ratio of 1.2:1 to 2:1, and using 100g to 120g per square meter, with 120g being the most preferred.

[0023] The application of water-based materials for beautifying and protecting fair-faced concrete, wherein the water-based materials are used in the durable protection and beautification of the surface of new or old concrete buildings, preferably, the application is that the amount of water-based materials used for coating or spraying on the surface of new or old concrete buildings is 100g to 120g, and most preferably 120g.

[0024] (III) Beneficial Effects

[0025] The beneficial effects of this invention are:

[0026] The water-based material for beautifying and protecting fair-faced concrete provided by this invention incorporates high-molecular polymer emulsion modification, which improves the material's cohesion and tensile strength. At the same time, because the water-based inorganic beautifying and protecting material is the same as the concrete matrix, it significantly improves the interfacial adhesion between the beautifying and protecting material and the concrete, with an adhesion strength greater than 2.5 MPa after 28 days.

[0027] The water-based material for beautifying and protecting fair-faced concrete of the present invention has good impermeability and freeze-thaw resistance and other durability properties: the secondary impermeability pressure can reach more than 0.6 MPa, and there is no cracking or peeling after 150 freeze-thaw cycles.

[0028] The water-based material for beautifying and protecting fair-faced concrete of the present invention incorporates defoamers and water-reducing agents, which can eliminate air bubbles generated during the mixing of the beautifying material, improve the pore structure and density of the beautifying material, enhance the strength and quality of the beautifying material, make the beautifying material more beautiful and robust, and effectively prevent the erosion of moisture and harmful substances.

[0029] The water-based material for beautifying and protecting fair-faced concrete of the present invention uses a polymer emulsion as a binder to mix and bond inorganic powders of different particle sizes together. Capillary pores are retained between the particles, and the water in the emulsion component used to adjust the viscosity will also react with the inorganic powders to a certain extent to generate a heat of hydration reaction, creating new capillary pores between the particles. When applied to fair-faced concrete, it can form a protective layer with capillary pores and one-way breathability, with a pore size of about 105-5010 nm. This allows water vapor (particle size about 0.4 nm) inside the concrete to diffuse outward, while preventing the penetration of water droplets (particle size between 0.1 and 7 mm). It has one-way breathing properties and can reproduce the original color and state of the concrete, improving the durability of the concrete.

[0030] The water-based material for beautification provided by this invention can penetrate into the concrete through capillaries, maintaining the performance of the permeable protective material. Detailed Implementation

[0031] Concrete contains mainly gel pores, capillaries, macropores, and numerous microcracks or defects. Gel pores typically have a diameter <10 nm, capillaries typically have a diameter between 100 and 1000 nm, and macropores have a diameter >1000 nm. It is generally believed that the strength and permeability of concrete are affected by medium-sized capillaries (10–50 nm) and large capillaries (50–10000 nm).

[0032] The water-based material for beautification and protection provided by this invention has the same main material as the concrete matrix, but the molding process is different. The inorganic powder and water in the emulsion provided by this invention undergo a hydration heat reaction with the water used to adjust the viscosity. At the same time, the emulsion acts as a binder, which can fill the pores and large pores, and bond the inorganic powder with different particle sizes and the concrete matrix generated by the reaction together. Therefore, the material of this invention has many medium and large capillary pores. Traditional film-forming materials form a dense, non-porous protective layer on the concrete surface, preventing external water droplets from penetrating and preventing internal water vapor from diffusing to the outside. When the diffusion force of water vapor at the interface exceeds the interfacial adhesion force, aging phenomena such as bulging and cracking easily occur. However, the water-based material for aesthetic protection provided by this invention can form a protective layer with capillary pores and one-way breathability. The pore size of the protective layer is about 10-50 nm, which does not hinder the diffusion of internal water vapor (particle size about 0.4 nm) to the outside, while preventing the penetration of water droplets (particle size between 0.1 and 7 mm). It has one-way breathability and can reproduce the original color and state of the concrete, improving the durability of the concrete. In other words, the water-based material for aesthetic protection provided by this invention has one-way breathability, meaning that internal water vapor can diffuse to the outside through this material, while external water droplets cannot pass through.

[0033] The material of this invention is modified with a polymer emulsion, which improves the material's cohesiveness and tensile strength, while also improving the stability of the colloid, adhesion, and anti-aging properties. Preferably, it is one or more of styrene-acrylic emulsions, vinyl acetate copolymer emulsions, silicone-acrylic emulsions, or acrylic emulsions. However, research has found that styrene-acrylic emulsions generally have poor weather resistance and are mostly used for interior walls; silicone-acrylic emulsions are weather-resistant, water-resistant, and stain-resistant, but are relatively expensive; acrylic emulsions in this invention offer good weather resistance and are moderately priced, making them more suitable for exterior walls; vinyl acetate copolymer emulsions in this invention exhibit good film-forming properties, high tensile strength, and low elongation at break. Therefore, acrylic emulsions or vinyl acetate copolymers are preferred as the main components. The material of this invention incorporates defoamers and water-reducing agents, which can eliminate air bubbles generated during the mixing of beautifying materials, improve the pore structure and density of the beautifying materials, enhance the strength and quality of the beautifying materials, make the appearance of the beautifying materials more beautiful and robust, and effectively prevent the erosion of moisture and harmful substances. Preferably, the defoamer is one or more of emulsified organosilicon, polysiloxane, and water-based organosilicon, and the water-reducing agent is one or more of modified polymer sulfonic acid, high molecular polymer viscosity modifier, and sulfonated melamine.

[0034] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below through specific embodiments.

[0035] Example 1

[0036] This embodiment provides a protective material for fair-faced concrete, comprising powder and polymer emulsion. The powder composition (by weight) is: 40 parts silicate cement, 13 parts aluminoferrite cement, 2 parts white cement, 13 parts S95 grade blast furnace slag powder, 10 parts sand powder (particle size 100-120 mesh), 4 parts titanium dioxide, and 15 parts fly ash (specific surface area ≥500 m²). 2 / kg), 3 parts sodium lignosulfonate dispersant. The composition of the polymer emulsion is (by weight): 50 parts vinyl acetate copolymer emulsion (non-volatile component (45±1)%, viscosity 800~1000mPa·s), 3.5 parts polysiloxane defoamer B-296 (milky white liquid or transparent liquid, pH 6.5~7.8), 1.5 parts modified polymer sulfonic acid water reducing agent (model FDN-Ⅰ), and water added to 100 parts.

[0037] Instructions for use: Mix the powder and polymer emulsion at a weight ratio of 1.8:1 until smooth and free of lumps. Specifically, first pour the powder into a container, then pour the emulsion into the container according to the recommended ratio. Then, use an electric mixer to mix at 550 rpm for 2 minutes. Apply the mixture using a roller brush. The material dosage is 120g per square meter.

[0038] After the powder and emulsion are mixed, an electric mixer is used to disperse the emulsion in cement mortar in the form of microparticles. With the formation of cement hydration products, an organic-inorganic interpenetrating matrix structure is formed. When the emulsion content reaches a certain proportion, a continuous network structure with a pore size of approximately 10–50 nm is formed. This gives the material unidirectional breathability without affecting the outward diffusion of water vapor from inside the concrete. Simultaneously, the mixture of powder and emulsion can penetrate into microcracks or pores of 1–2 mm on the concrete surface, forming an interwoven structure. Therefore, the material of this invention has better bonding strength, toughness, and impact resistance than cement-based materials. It should be noted that the powder and emulsion provided by this invention need to be packaged separately and mixed before use, as they react after mixing. The mixture must be used within 24 hours after mixing; otherwise, it will solidify and become unusable.

[0039] Example 2

[0040] This embodiment provides a beautification and protective material for fair-faced concrete, comprising powder and polymer emulsion. The composition of the powder (by weight) is as follows:

[0041] 40 parts silicate cement, 15 parts ferroaluminate cement, 13 parts S95 grade blast furnace slag powder, 10 parts sand powder (particle size 100-120 mesh), 4 parts titanium dioxide, 15 parts fly ash (specific surface area ≥500 m²) 2 / kg), 3 parts lignin sulfonate dispersant.

[0042] The composition of the polymer emulsion is as follows (by weight): 53 parts acrylic emulsion (solid content (57±1)%, viscosity 300~750mPa·s), 3.5 parts water-based silicone defoamer B-313 (milky white liquid, pH 6.5~7.8), 1.5 parts sulfonated melamine water-reducing agent (model SM), and water added to 100 parts.

[0043] Instructions for use: Mix the powder and polymer emulsion at a weight ratio of 1.25:1 until smooth and free of lumps. Specifically, first pour the powder into a container, then pour the emulsion into the container according to the recommended ratio. Then, use an electric mixer to mix at 550 rpm for 2 minutes. Apply the mixture using a roller brush. The material dosage is 120g per square meter.

[0044] Example 3

[0045] This embodiment provides a beautification and protective material for fair-faced concrete, comprising powder and polymer emulsion. The composition of the powder is (by weight):

[0046] 40 parts silicate cement, 15 parts ferroaluminate cement, 13 parts S95 grade blast furnace slag powder, 10 parts sand powder (particle size 100-120 mesh), 4 parts titanium dioxide, 15 parts fly ash (specific surface area ≥500 m²)2 / kg), 3 parts lignin sulfonate dispersant.

[0047] The composition of the polymer emulsion is as follows (by weight): 51 parts styrene-acrylic emulsion (solid content (56±1)%, viscosity 900~1200mPa·s), 3.5 parts polysiloxane defoamer B-313 (milky white liquid, pH 6.5~7.8), 1.5 parts sulfonated melamine water-reducing agent (model SM), and water added to 100 parts.

[0048] Instructions for use: Mix the powder and polymer emulsion at a weight ratio of 1.5:1 until smooth and free of lumps. Specifically, first pour the powder into a container, then pour the emulsion into the container according to the recommended ratio. Then, use an electric mixer to mix at 550 rpm for 2 minutes. Apply the mixture using a roller brush. The material dosage is 120g per square meter.

[0049] Comparative Example 1

[0050] Based on Example 1, the amount of titanium dioxide added was changed to 2 parts, the amount of white cement added was changed to 4 parts, and other parameters remained unchanged.

[0051] Comparative Example 2

[0052] Based on Example 1, the amount of titanium dioxide added was changed to 0 parts, the amount of white cement added was changed to 6 parts, and other parameters remained unchanged.

[0053] Comparative Example 3

[0054] Traditional acrylic resin coatings are used to beautify and protect fair-faced concrete, with a material usage of 120g per square meter.

[0055] Comparative Example 4

[0056] Based on Comparative Example 1, the material usage was changed to 220g per square meter.

[0057] Comparative Examples 5-7

[0058] Based on Examples 1 to 3, the material usage was changed to 220g per square meter.

[0059] The product obtained according to the above proportions shall be constructed according to the specified material usage. Its main performance indicators shall be tested in accordance with GBT50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete" and GBT 50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete". The specific results are shown in Tables 3 and 4 below.

[0060] Table 3 Performance indicators of each embodiment and comparative example

[0061]

[0062] Table 4 Performance Indicators of Each Comparative Example

[0063]

[0064] As can be seen from the performance indicators tested in Examples 1-3, the beautification and protection effect of the vinyl acetate copolymer emulsion is the best. A comparison with the performance indicators tested in Comparative Examples 1-2 shows that only the product with 4 parts titanium dioxide and 2 parts white cement has an appearance color closest to the original color of fair-faced concrete and achieves the best performance indicators and anti-aging properties. Less than 2 parts titanium dioxide or more than 4 parts white cement cannot maintain the original color of fair-faced concrete. The performance indicators tested in Examples 1 and 3 show that the performance of the material of this invention is superior to that of traditional materials, exhibiting excellent adhesion, anti-aging properties, and one-way breathability. A comparison with the performance indicators tested in Comparative Examples 5-7 shows that the optimal dosage of the beautification and protection material is 120g per square meter.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art can make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A water-based material for the beautification and protection of fair-faced concrete, characterized in that, It comprises the following components by weight: powder: 40-55 parts cement, 5-15 parts sand powder, 5-15 parts mineral powder, 1-3 parts dispersing and suspending agent, 3-5 parts titanium dioxide, and 5-15 parts fly ash; wherein the cement is 40 parts silicate cement, 13 parts aluminoferrite cement, and 2 parts white cement; and the dispersing and suspending agent is lignin sulfonate. Emulsion: 45-55 parts of polymer emulsion, 1-5 parts of defoamer, 0.5-1.5 parts of water-reducing agent, and 30-40 parts of water; The polymer emulsion is one or more of styrene-acrylic emulsion, vinyl acetate copolymer emulsion, silicone-acrylic emulsion, or acrylic emulsion; The defoamer is one or more of polysiloxane and water-based silicone defoamers; The water-reducing agent is a sulfonated melamine-based water-reducing agent; When using, mix the powder and emulsion evenly at a weight ratio of 1.2:1 to 2:1, and use 100g to 120g per square meter.

2. The water-based material as described in claim 1, characterized in that, The sand powder has a mesh size of 100-120; the mineral powder is grade S95; and the fly ash has a specific surface area ≥500 m². 2 / kg.

3. The application of the water-based material for beautifying and protecting fair-faced concrete as described in claim 1 or 2 in the durable protection and beautification of new or old concrete building surfaces, characterized in that, The application refers to the application of the water-based material to the surface of new or old concrete buildings by coating or spraying it at a dosage of 100g to 120g per square meter.

Images