A concrete anti-cracking and anti-seepage enhancer and preparation method thereof

Abstract

The invention discloses a concrete anti-cracking and anti-seepage enhancer and a preparation method thereof. The concrete anti-cracking and anti-seepage enhancer comprises cellulose ether, polymer emulsion, cement, nano-silicon dioxide, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture. The concrete anti-cracking and anti-seepage enhancer improves the cohesion and toughness of concrete by adding cellulose ether and polyacrylamide particles, reduces the formation of cracks, and the addition of steel fiber further enhances the tensile strength and anti-cracking performance of concrete; nano-silicon dioxide and polyurethane enhancer are used to fill the micro pores inside the concrete, significantly reducing the permeability, and the addition of waterproofing agent improves the waterproof performance of concrete. The polymer emulsion and alkyl sulfonate are used to improve the workability and fluidity of concrete, and the comprehensive performance of concrete is also improved by adding mineral admixtures. The invention has significant anti-cracking and anti-seepage performance.

Description

Technical Field

[0001] The invention relates to the field of building materials, and in particular to a concrete anti-cracking and anti-seepage enhancing agent and a preparation method thereof. Background Art

[0002] Concrete is one of the most commonly used materials in construction projects, with good mechanical properties and durability. However, ordinary concrete has certain permeability problems, especially when exposed to water or other liquid environments for a long time, the permeability will cause the internal structure of the concrete to be damaged, thus affecting its service life. This permeability problem is particularly prominent in projects that are in long-term contact with water, such as underground projects, bridges, and tunnels. In addition, during the construction and use of concrete, cracks caused by permeability are also a common and unavoidable problem. These cracks not only affect the beauty of the structure, but may also cause the concrete's impermeability to decrease. The presence of cracks has a great impact on the safety and durability of the concrete structure. The main manifestation is the reduction of structural strength. Cracks weaken the integrity of the concrete and reduce its bearing capacity; affect the waterproof performance. Cracks provide a channel for water and other corrosive substances to enter the interior of the concrete, which easily causes steel corrosion and further weakens the structural performance; shorten the service life. Cracks accelerate the aging and deterioration of concrete and shorten the service life of the building.

[0003] In order to improve the anti-cracking and anti-seepage performance of concrete, various reinforcing agents have appeared on the market. However, existing reinforcing agents generally have the disadvantages of insignificant reinforcing effect, complex construction and poor compatibility. In recent years, with the development of science and technology, researchers have continued to deepen their research on concrete reinforcing agents, usually by adding waterproofing agents to concrete or using waterproof coatings to improve its anti-seepage performance. However, in these research methods, waterproofing agents are easily affected by concrete mix ratios and construction processes, and their effects are difficult to guarantee. Moreover, waterproofing agents may decompose or fail during long-term use, resulting in a decrease in the anti-seepage ability of concrete. In addition, waterproof coatings are susceptible to external mechanical damage. Once the coating is damaged, the waterproof effect will be greatly reduced. Moreover, the coating construction is complicated, which increases the construction cost and time. In addition, although the existing foamed concrete technology can improve the lightweight and thermal insulation properties of concrete by introducing bubbles, due to the instability of the bubble structure, it often leads to a decrease in the strength and durability of concrete, and fails to significantly improve its anti-seepage performance.

[0004] Therefore, how to develop a concrete reinforcing agent with excellent anti-cracking and anti-seepage properties, easy to use and environmentally friendly, remains an important research direction in the field of building materials. Summary of the invention

[0005] In view of this, the present invention aims to provide a concrete anti-cracking and anti-seepage enhancer and a preparation method thereof, which can not only effectively improve the anti-cracking and anti-seepage properties of concrete, but also has the characteristics of being easy to use and environmentally friendly.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0008] 2-6 parts of cellulose ether; 5-10 parts of polymer emulsion; 30-40 parts of cement; 4-10 parts of nano silicon dioxide; 1-3 parts of polyacrylamide particles; 1-3 parts of polyurethane; 2-8 parts of steel fiber; 8-15 parts of calcium sulfoaluminate; 1-3 parts of alkyl sulfonate; 1-4 parts of waterproofing agent; 10-15 parts of mineral admixture.

[0009] As a further solution of the present invention, the concrete anti-cracking and anti-seepage enhancer includes the following raw materials in parts by weight: 4 parts of cellulose ether; 7.5 parts of polymer emulsion; 35 parts of cement; 7 parts of nano-silicon dioxide; 2 parts of polyacrylamide particles; 2 parts of polyurethane; 5 parts of steel fiber; 11.5 parts of calcium sulfoaluminate; 2 parts of alkyl sulfonate; 2.5 parts of waterproofing agent; and 12.5 parts of mineral admixture.

[0010] As a further embodiment of the present invention, the cellulose ether is hydroxypropyl methylcellulose (HPMC) with a viscosity ranging from 5000 to 200000 mPa·s (2% solution, 20° C.); a degree of substitution (DS) of 1.2 to 2.0; a hydroxypropyl content of 4% to 12%; a methoxy content of 19% to 30%; a moisture content of ≤5%; and a pH value of 6 to 8 (1% aqueous solution).

[0011] As a further scheme of the present invention, the cellulose ether is prepared by mixing natural cellulose with a sodium hydroxide solution, performing an alkalization treatment, and mixing the alkalized cellulose with propylene oxide and methyl chloride for an etherification reaction, wherein the etherification reaction temperature is controlled at 50-80° C., and the etherification reaction replaces the hydroxyl groups on the cellulose molecules with methoxyl groups and hydroxypropyl groups to form hydroxypropyl methylcellulose; after the reaction is completed, the reaction mixture is neutralized with acetic acid, and washed and neutralized with water to obtain the cellulose ether, wherein the washed cellulose ether is dried to a water content of ≤5%.

[0012] As a further embodiment of the present invention, the polymer emulsion comprises the following raw materials in parts by weight:

[0013] 20-50 parts of base monomer; 10-30 parts of comonomer; 0.5-2 parts of initiator; 0.5-3 parts of emulsifier; 1-5 parts of stabilizer; 0.1-1 parts of preservative; 0.1-1 parts of defoamer; appropriate amount of PH regulator.

[0014] As a further solution of the present invention, the base monomer is composed of styrene, acrylic acid and methacrylic acid, wherein styrene is 10-30 parts; acrylic acid is 5-10 parts; and methacrylic acid is 5-10 parts.

[0015] As a further embodiment of the present invention, the comonomer is butyl acrylate or methyl methacrylate; the initiator is potassium persulfate (KPS); the emulsifier is sodium dodecyl sulfate; the stabilizer is polyvinyl alcohol (PVA); and the pH adjuster is sodium hydroxide or sodium acetate.

[0016] As a further embodiment of the present invention, the polyacrylamide particles include the following raw materials in parts by weight:

[0017] 80-99 parts of acrylamide, 1-20 parts of methacrylamide, 0.05-0.5 parts of ammonium persulfate (APS), 0.1-1 parts of methylene bisacrylamide, and 0.1-1 parts of hydroxyethyl cellulose (HEC).

[0018] As a further scheme of the present invention, when preparing the polyacrylamide particles, acrylamide and methacrylamide weighed in parts by weight are dissolved in deionized water, ammonium persulfate is added under stirring, the temperature is controlled at 40-60° C., acrylamide and methacrylamide monomers are polymerized, methylene bisacrylamide and hydroxyethyl cellulose are added to form a network structure of the polymer, and the polymer solution is dried to obtain polyacrylamide particles.

[0019] As a further solution of the present invention, the steel fiber has a length of 20-50 mm, a diameter of 0.2-1 mm, and a strength of >1000 MPa.

[0020] As a further embodiment of the present invention, the alkyl sulfonate is dodecylbenzene sulfonate, and the waterproofing agent is methyltriethoxysilane.

[0021] As a further solution of the present invention, the mineral admixture is composed of fly ash, slag powder and silica fume, and the fineness is such that the residue passing through a 45-micron sieve generally does not exceed 10%, and the water content does not exceed 1%.

[0022] In a second aspect, the present invention also provides a method for preparing a concrete anti-cracking and anti-seepage enhancer, the steps of which are as follows:

[0023] 1) weighing cellulose ether, polymer emulsion, cement, nano-silica, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture according to weight parts for use;

[0024] 2) adding cellulose ether and polyacrylamide particles into a mixer for premixing, and slowly adding polymer emulsion, stirring at a speed of 200-250 r / min, stirring for 10-15 minutes, and controlling the temperature at 25° C., then adding cement, and continuing stirring for 20-30 minutes to obtain a premix;

[0025] 3) Slowly adding nano-silicon dioxide and polyurethane to the premix and continuing stirring for 10-15 minutes, and gradually adding steel fiber, stirring at a speed of 150-200 r / min, stirring for 20-30 minutes, during which calcium sulphoaluminate is added to obtain a reinforced mixture;

[0026] 4) Slowly add alkyl sulfonate waterproofing agent to the enhanced mixture, continue stirring at 200-250r / min for 5-10 minutes, finally add mineral admixture, continue stirring for 20-30 minutes until the mineral admixture is completely mixed, and obtain the final mixture based on concrete anti-cracking and anti-seepage enhancer, put it into a sealed container, and store it in a dry and cool place for use.

[0027] Compared with the prior art, the concrete anti-cracking and anti-seepage enhancer and the preparation method thereof of the present invention have the following beneficial effects:

[0028] 1. Enhanced crack resistance: The addition of cellulose ether and polyacrylamide particles improves the adhesion and toughness of concrete, reduces the formation of cracks, and the addition of steel fibers further enhances the tensile strength and crack resistance of concrete.

[0029] 2. Improved anti-seepage performance: Nano-silica and polyurethane reinforcing agents are used to fill the tiny pores inside the concrete, which significantly reduces the permeability. The addition of waterproofing agents further improves the waterproof performance of the concrete and prevents moisture from entering.

[0030] 3. Optimized construction performance: The use of polymer emulsion and alkyl sulfonate improves the workability and fluidity of concrete, making construction more convenient and quicker. The presence of calcium sulfoaluminate accelerates the early strength development of concrete and shortens the curing time. The addition of mineral admixtures further improves the comprehensive performance of concrete, including durability, freeze-thaw resistance and corrosion resistance.

[0031] In summary, the concrete anti-cracking and anti-seepage enhancer obtained by the preparation method of the present invention has significant anti-cracking and anti-seepage properties, while optimizing the construction performance and early strength development, and is suitable for concrete projects in various complex environments, providing reliable guarantee for project quality and durability.

[0032] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with specific embodiments. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0034] Example 1

[0035] The present embodiment provides a concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0036] 2 parts of cellulose ether; 5 parts of polymer emulsion; 30 parts of cement; 4 parts of nano-silicon dioxide; 1 part of polyacrylamide particles; 1 part of polyurethane; 2 parts of steel fiber; 8 parts of calcium sulfoaluminate; 1 part of alkyl sulfonate; 1 part of waterproofing agent; 10 parts of mineral admixture.

[0037] In this embodiment, the cellulose ether is hydroxypropyl methylcellulose (HPMC) with a viscosity range of 5000-200000 mPa·s (2% solution, 20° C.); a degree of substitution (DS) of 1.5; a hydroxypropyl content of 8%; a methoxy content of 20%; a moisture content of ≤5%; and a pH value of 7 (1% aqueous solution).

[0038] The cellulose ether is prepared by mixing natural cellulose with a sodium hydroxide solution, performing an alkalization treatment, and mixing the alkalized cellulose with propylene oxide and methyl chloride for an etherification reaction, wherein the etherification reaction temperature is controlled at 60°C, and the etherification reaction replaces the hydroxyl groups on the cellulose molecules with methoxyl groups and hydroxypropyl groups to form hydroxypropyl methylcellulose; after the reaction is completed, the reaction mixture is neutralized with acetic acid, and the cellulose ether is obtained after washing and neutralization with water, wherein the washed cellulose ether is dried to a water content of ≤5%.

[0039] In this embodiment, by combining cellulose ether with polymer emulsion, the polymer emulsion can be thickened, its dispersibility and stability in concrete can be improved, and cellulose ether can effectively retain water, extend the working time of concrete, and improve the bonding performance of polymer emulsion; at the same time, the added cellulose ether can also be combined with polyacrylamide particles, and the viscosity and water retention of concrete can be significantly improved through the joint action of cellulose ether and polyacrylamide particles. The combination of the two can improve the fluidity and self-compacting performance of concrete and make the concrete more uniform. In addition, the added cellulose ether can also be combined with polyurethane and steel fiber. After the cellulose ether is combined with polyurethane, the waterproof performance of concrete can be improved and water penetration can be reduced. The cellulose ether can also improve the interfacial bonding between steel fiber and concrete matrix and enhance the crack resistance of concrete. Through the synergistic effect of the above cellulose ether and the above components, the comprehensive performance of the concrete anti-cracking and anti-seepage enhancer can be significantly improved to meet the needs of engineering applications.

[0040] In this embodiment, the polymer emulsion includes the following raw materials in parts by weight: 20 parts of base monomer; 10 parts of comonomer; 0.5 parts of initiator; 0.5 parts of emulsifier; 1 part of stabilizer; 0.1 parts of preservative; 0.1 parts of defoamer; and an appropriate amount of pH regulator. The base monomer is composed of styrene, acrylic acid and methacrylic acid, wherein styrene is 10 parts; acrylic acid is 5 parts; methacrylic acid is 5 parts; the comonomer is butyl acrylate or methyl methacrylate; the initiator is potassium persulfate (KPS); the emulsifier is sodium dodecyl sulfate; the stabilizer is polyvinyl alcohol (PVA); and the pH regulator is sodium hydroxide or sodium acetate.

[0041] The polymer emulsion is prepared by mixing the base monomer and the comonomer with an emulsifier to form a pre-emulsion, initiating a polymerization reaction under the action of an initiator, gradually adding the pre-emulsion, adding a stabilizer, a preservative, a defoamer, etc., adjusting the pH value, and obtaining a finished emulsion. In the prepared polymer emulsion, the base monomer and the comonomer form a polymer skeleton through a copolymerization reaction, the initiator decomposes to generate free radicals, initiates the polymerization reaction of the monomer, controls the rate of the polymerization process and the molecular weight of the polymer, the emulsifier forms micelles in the aqueous phase, encapsulates the monomer, stabilizes the emulsion system, prevents the aggregation and sedimentation of the monomer and polymer particles during the polymerization process, increases the viscosity of the emulsion and the electrostatic repulsion between the particles through the stabilizer, and the preservative prolongs the storage life of the emulsion to prevent microbial contamination; the defoamer inhibits or eliminates foam during the production process to improve production efficiency.

[0042] In this embodiment, the polyacrylamide particles include the following raw materials in parts by weight: 80 parts of acrylamide, 1 part of methacrylamide, 0.05 parts of ammonium persulfate, 0.1 parts of methylene bisacrylamide, and 0.1 parts of hydroxyethyl cellulose. When preparing the polyacrylamide particles, acrylamide and methacrylamide weighed in parts by weight are dissolved in deionized water, ammonium persulfate is added under stirring, the temperature is controlled at 50° C., acrylamide and methacrylamide monomers are polymerized, methylene bisacrylamide and hydroxyethyl cellulose are added, the polymer forms a network structure, and the polymer solution is dried to obtain polyacrylamide particles.

[0043] In this embodiment, the steel fiber has a length of 25 mm, a diameter of 0.35 mm, and a strength of >1000 MPa; the alkyl sulfonate is dodecylbenzene sulfonate, and the waterproofing agent is methyl triethoxysilane. The mineral admixture is composed of fly ash, slag powder and silica fume, and the fineness is generally no more than 10% of the residue passing through a 45-micron sieve, and the water content is no more than 1%.

[0044] The preparation method of the concrete anti-cracking and anti-seepage enhancer in this embodiment comprises the following steps:

[0045] 1) weighing cellulose ether, polymer emulsion, cement, nano-silica, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture according to weight parts for use;

[0046] 2) adding cellulose ether and polyacrylamide particles into a mixer for premixing, and slowly adding polymer emulsion, stirring at a speed of 200 r / min, stirring for 15 minutes, and controlling the temperature at 25° C., then adding cement, and continuing stirring for 30 minutes to obtain a premix;

[0047] 3) Slowly adding nano-silicon dioxide and polyurethane to the premix and continuing stirring for 15 minutes, and gradually adding steel fiber, stirring at a speed of 200 r / min, stirring for 20 minutes, during which calcium sulphoaluminate was added to obtain a reinforced mixture;

[0048] 4) Slowly add alkyl sulfonate waterproofing agent to the enhanced mixture, continue stirring at 250r / min for 5 minutes, finally add mineral admixture, continue stirring for 20 minutes until the mineral admixture is completely mixed, and obtain the final mixture based on concrete anti-cracking and anti-seepage enhancer. Put it into a sealed container and store it in a dry and cool place for use.

[0049] Example 2

[0050] Different from Example 1, this embodiment provides a concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0051] 3 parts of cellulose ether; 6 parts of polymer emulsion; 32 parts of cement; 6 parts of nano-silicon dioxide; 1.5 parts of polyacrylamide particles; 1.5 parts of polyurethane; 3 parts of steel fiber; 9 parts of calcium sulfoaluminate; 1.5 parts of alkyl sulfonate; 2 parts of waterproofing agent; 12 parts of mineral admixture.

[0052] In this embodiment, the polymer emulsion includes the following raw materials in parts by weight: 35 parts of base monomer; 20 parts of comonomer; 1.5 parts of initiator; 2 parts of emulsifier; 3 parts of stabilizer; 0.5 parts of preservative; 0.5 parts of defoaming agent; and an appropriate amount of pH regulator; wherein the base monomer is composed of styrene, acrylic acid and methacrylic acid, wherein styrene is 20 parts; acrylic acid is 7 parts; and methacrylic acid is 8 parts.

[0053] The polyacrylamide particles include the following raw materials in parts by weight: 85 parts of acrylamide, 4 parts of methacrylamide, 0.2 parts of ammonium persulfate (APS), 0.3 parts of methylenebisacrylamide, and 0.5 parts of hydroxyethylcellulose (HEC). When preparing the polyacrylamide particles, acrylamide and methacrylamide weighed in parts by weight are dissolved in deionized water, ammonium persulfate is added under stirring, the temperature is controlled at 40° C., acrylamide and methacrylamide monomers are polymerized, methylenebisacrylamide and hydroxyethylcellulose are added, the polymer forms a network structure, and the polymer solution is dried to obtain polyacrylamide particles.

[0054] In this embodiment, the steel fiber has a length of 25 mm and a diameter of 0.5 mm.

[0055] The preparation method of the concrete anti-cracking and anti-seepage enhancer in this embodiment comprises the following steps:

[0056] 1) weighing cellulose ether, polymer emulsion, cement, nano-silica, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture according to weight parts for use;

[0057] 2) adding cellulose ether and polyacrylamide particles into a mixer for premixing, and slowly adding polymer emulsion, stirring at a speed of 220 r / min, stirring for 12 minutes, and controlling the temperature at 25° C., then adding cement, and continuing stirring for 25 minutes to obtain a premix;

[0058] 3) Slowly adding nano-silicon dioxide and polyurethane to the premix and continuing stirring for 13 minutes, and gradually adding steel fiber, stirring at a speed of 180 r / min, stirring for 25 minutes, during which calcium sulphoaluminate was added to obtain a reinforced mixture;

[0059] 4) Slowly add alkyl sulfonate waterproofing agent to the reinforced mixture, continue stirring at 220r / min for 7 minutes, finally add mineral admixture, continue stirring for 25 minutes until the mineral admixture is completely mixed, and obtain the final mixture based on concrete anti-cracking and anti-seepage enhancer. Put it into a sealed container and store it in a dry and cool place for use.

[0060] Example 3

[0061] Different from Example 1, this embodiment provides a concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0062] 4 parts of cellulose ether; 7.5 parts of polymer emulsion; 35 parts of cement; 7 parts of nano-silicon dioxide; 2 parts of polyacrylamide particles; 2 parts of polyurethane; 5 parts of steel fiber; 11.5 parts of calcium sulfoaluminate; 2 parts of alkyl sulfonate; 2.5 parts of waterproofing agent; 12.5 parts of mineral admixture.

[0063] The preparation method of the concrete anti-cracking and anti-seepage enhancer in this embodiment comprises the following steps:

[0064] 1) weighing cellulose ether, polymer emulsion, cement, nano-silica, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture according to weight parts for use;

[0065] 2) adding cellulose ether and polyacrylamide particles into a mixer for premixing, and slowly adding polymer emulsion, stirring at a speed of 250 r / min, stirring for 10 minutes, and controlling the temperature at 25° C., then adding cement, and continuing stirring for 20 minutes to obtain a premix;

[0066] 3) Slowly adding nano-silicon dioxide and polyurethane to the premix and continuing stirring for 10 minutes, and gradually adding steel fiber, stirring at a speed of 200 r / min, stirring for 30 minutes, during which calcium sulphoaluminate was added to obtain a reinforced mixture;

[0067] 4) Slowly add alkyl sulfonate waterproofing agent to the enhanced mixture, continue stirring at 250r / min for 5 minutes, finally add mineral admixture, continue stirring for 30 minutes until the mineral admixture is completely mixed, and obtain the final mixture based on concrete anti-cracking and anti-seepage enhancer. Put it into a sealed container and store it in a dry and cool place for use.

[0068] Example 4

[0069] Different from Example 1, this embodiment provides a concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0070] 4 parts of cellulose ether; 8 parts of polymer emulsion; 38 parts of cement; 8 parts of nano silicon dioxide; 2 parts of polyacrylamide particles; 2 parts of polyurethane; 6 parts of steel fiber; 12 parts of calcium sulfoaluminate; 2 parts of alkyl sulfonate; 3 parts of waterproofing agent; 13 parts of mineral admixture.

[0071] In this embodiment, the polymer emulsion includes the following raw materials in parts by weight: 40 parts of base monomer; 25 parts of comonomer; 1.5 parts of initiator; 2.5 parts of emulsifier; 4 parts of stabilizer; 0.8 parts of preservative; 0.8 parts of defoaming agent; and an appropriate amount of pH regulator; wherein the base monomer is composed of styrene, acrylic acid and methacrylic acid, wherein styrene is 20 parts; acrylic acid is 10 parts; and methacrylic acid is 10 parts.

[0072] The polyacrylamide particles include the following raw materials in parts by weight: 95 parts of acrylamide, 18 parts of methacrylamide, 0.4 parts of ammonium persulfate (APS), 0.8 parts of methylenebisacrylamide, and 0.8 parts of hydroxyethylcellulose (HEC). When preparing the polyacrylamide particles, acrylamide and methacrylamide weighed in parts by weight are dissolved in deionized water, ammonium persulfate is added under stirring, the temperature is controlled at 60° C., acrylamide and methacrylamide monomers are polymerized, methylenebisacrylamide and hydroxyethylcellulose are added, the polymer forms a network structure, and the polymer solution is dried to obtain polyacrylamide particles.

[0073] In this embodiment, the steel fiber has a length of 40 mm and a diameter of 0.8 mm.

[0074] The preparation method of the concrete anti-cracking and anti-seepage enhancer in this embodiment comprises the following steps:

[0075] 1) weighing cellulose ether, polymer emulsion, cement, nano-silica, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture according to weight parts for use;

[0076] 2) adding cellulose ether and polyacrylamide particles into a mixer for premixing, and slowly adding polymer emulsion, stirring at a speed of 240 r / min, stirring for 14 minutes, and controlling the temperature at 25° C., then adding cement, and continuing stirring for 25 minutes to obtain a premix;

[0077] 3) Slowly adding nano-silicon dioxide and polyurethane to the premix and continuing stirring for 13 minutes, and gradually adding steel fiber, stirring at a speed of 180 r / min, stirring for 25 minutes, during which calcium sulphoaluminate was added to obtain a reinforced mixture;

[0078] 4) Slowly add alkyl sulfonate waterproofing agent to the enhanced mixture, continue stirring at 230r / min for 10 minutes, finally add mineral admixture, continue stirring for 30 minutes until the mineral admixture is completely mixed, and obtain the final mixture based on concrete anti-cracking and anti-seepage enhancer. Put it into a sealed container and store it in a dry and cool place for use.

[0079] Example 5

[0080] Different from Example 1, this embodiment provides a concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0081] 6 parts of cellulose ether; 10 parts of polymer emulsion; 40 parts of cement; 10 parts of nano silicon dioxide; 3 parts of polyacrylamide particles; 3 parts of polyurethane; 8 parts of steel fiber; 15 parts of calcium sulfoaluminate; 3 parts of alkyl sulfonate; 4 parts of waterproofing agent; 15 parts of mineral admixture.

[0082] In this embodiment, the polymer emulsion includes the following raw materials in parts by weight: 50 parts of base monomer; 30 parts of comonomer; 2 parts of initiator; 3 parts of emulsifier; 5 parts of stabilizer; 1 part of preservative; 1 part of defoaming agent; and an appropriate amount of pH regulator; wherein the base monomer is composed of styrene, acrylic acid and methacrylic acid, wherein styrene is 30 parts; acrylic acid is 10 parts; and methacrylic acid is 10 parts.

[0083] The polyacrylamide particles include the following raw materials in parts by weight: 99 parts of acrylamide, 20 parts of methacrylamide, 0.5 parts of ammonium persulfate (APS), 1 part of methylenebisacrylamide, and 1 part of hydroxyethyl cellulose (HEC). When preparing the polyacrylamide particles, acrylamide and methacrylamide weighed in parts by weight are dissolved in deionized water, ammonium persulfate is added under stirring, the temperature is controlled at 60° C., acrylamide and methacrylamide monomers are polymerized, methylenebisacrylamide and hydroxyethyl cellulose are added, the polymer forms a network structure, and the polymer solution is dried to obtain polyacrylamide particles.

[0084] In this embodiment, the steel fiber has a length of 50 mm and a diameter of 1 mm.

[0085] The preparation method of the concrete anti-cracking and anti-seepage enhancer in this embodiment comprises the following steps:

[0086] 1) weighing cellulose ether, polymer emulsion, cement, nano-silica, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture according to weight parts for use;

[0087] 2) adding cellulose ether and polyacrylamide particles into a mixer for premixing, and slowly adding polymer emulsion, stirring at a speed of 250 r / min, stirring for 10 minutes, and controlling the temperature at 25° C., then adding cement, and continuing stirring for 30 minutes to obtain a premix;

[0088] 3) Slowly adding nano-silicon dioxide and polyurethane to the premix and continuing stirring for 15 minutes, and gradually adding steel fiber, stirring at a speed of 200 r / min, stirring for 20 minutes, during which calcium sulphoaluminate was added to obtain a reinforced mixture;

[0089] 4) Slowly add alkyl sulfonate waterproofing agent to the enhanced mixture, continue stirring at 250r / min for 10 minutes, finally add mineral admixture, continue stirring for 30 minutes until the mineral admixture is completely mixed, and obtain the final mixture based on concrete anti-cracking and anti-seepage enhancer. Put it into a sealed container and store it in a dry and cool place for use.

[0090] Comparative Example 1

[0091] A concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0092] 5 parts of polymer emulsion; 30 parts of cement; 4 parts of nano silicon dioxide; 1 part of polyacrylamide particles; 1 part of polyurethane; 2 parts of steel fiber; 8 parts of calcium sulfoaluminate; 1 part of alkyl sulfonate; 1 part of waterproofing agent; 10 parts of mineral admixture. Among them, the concrete anti-cracking and anti-seepage enhancer does not contain cellulose ether.

[0093] Comparative Example 2

[0094] A concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0095] 2 parts of cellulose ether; 30 parts of cement; 4 parts of nano silicon dioxide; 1 part of polyacrylamide particles; 1 part of polyurethane; 2 parts of steel fiber; 8 parts of calcium sulfoaluminate; 1 part of alkyl sulfonate; 1 part of waterproofing agent; 10 parts of mineral admixture. Among them, the concrete anti-cracking and anti-seepage enhancer does not contain polymer emulsion.

[0096] Comparative Example 3

[0097] A concrete anti-cracking and anti-seepage enhancer, comprising the following raw materials in parts by weight:

[0098] 30 parts of cement; 4 parts of nano silicon dioxide; 1 part of polyacrylamide particles; 1 part of polyurethane; 2 parts of steel fiber; 8 parts of calcium sulfoaluminate; 1 part of alkyl sulfonate; 1 part of waterproofing agent; 10 parts of mineral admixture. Among them, the concrete anti-cracking and anti-seepage enhancer does not contain cellulose ether and polymer emulsion.

[0099] The preparation processes of Comparative Examples 1-3 are the same as those of Example 1.

[0100] Effect verification:

[0101] The concrete anti-cracking and anti-seepage enhancing agents prepared in Examples 1-5 and the concrete anti-cracking and anti-seepage enhancing agents prepared in Comparative Examples 1-3 were subjected to the following tests:

[0102] (1) Splitting tensile strength test

[0103] Test item: splitting tensile strength.

[0104] Test method: The concrete specimens prepared in Examples 1-5 and Comparative Examples 1-3 were selected, which were cylinders with a diameter of 150 mm and a height of 300 mm. The curing conditions were a temperature of 20±2° C., a humidity of more than 95%, and a curing period of 28 days. The standard was ASTM C496 / C496M. During the test, the specimens were prepared and marked. After curing for 28 days, a splitting tensile test was performed on a testing machine, and the load at which the specimens broke was recorded. The test result data is shown in Table 1.

[0105] (2) Compressive strength test

[0106] Test item: compressive strength.

[0107] Test method: Select standard specimens prepared in Examples 1-5 and Comparative Examples 1-3, 150mm×150mm×150mm cubes; curing conditions are temperature 20±2°C, humidity above 95%, and curing for 28 days; based on the standard ASTM C39 / C39M; during the test, prepare and cure the specimens, perform a compressive strength test after the curing period, record the failure load of each specimen, and the test result data is shown in Table 1.

[0108] (3) Penetration test

[0109] Test item: Permeability.

[0110] Test method: Select the standard specimens prepared in Examples 1-5 and Comparative Examples 1-3, which are cylinders with a diameter of 100 mm and a height of 100 mm; the curing conditions are a temperature of 20±2°C, a humidity of more than 95%, and a curing period of 28 days; the standard is ASTM C1202; during the test, prepare and cure the specimens, use the flux method to determine the permeability of the concrete, and record the amount of charge passing through the specimens. The test result data is shown in Table 1.

[0111] (4) Shrinkage deformation test

[0112] Test item: Concrete shrinkage performance.

[0113] Test method: Select the standard specimens prepared in Examples 1-5 and Comparative Examples 1-3, 100mm×100mm×500mm prisms, and continue to cure in a dry environment (20±2°C, relative humidity 50±5%) after 28 days of standard curing. Regularly measure the length change and calculate the shrinkage deformation. The test results are shown in Table 1.

[0114] Table 1 Concrete anti-cracking and anti-seepage enhancer test results

[0115]

[0116]

[0117] Through the above-mentioned multiple tests, the concrete anti-cracking and anti-seepage enhancers prepared in Examples 1-5 showed excellent performance in terms of anti-seepage performance, tensile strength performance, compressive strength performance and shrinkage deformation effect, especially in Example 2 and Example 5, whose various performance indicators were at a high level, showing good application prospects and practical use value.

[0118] The concrete anti-cracking and anti-seepage enhancer of the present invention not only has significant anti-cracking and anti-seepage properties, but also optimizes construction performance and early strength development. It is suitable for concrete projects in various complex environments and provides reliable guarantee for project quality and durability.

[0119] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A concrete anti-cracking and anti-seepage enhancer, characterized in that: The invention comprises the following raw materials in parts by weight: 2-6 parts of cellulose ether; 5-10 parts of polymer emulsion; 30-40 parts of cement; 4-10 parts of nano-silicon dioxide; 1-3 parts of polyacrylamide particles; 1-3 parts of polyurethane; 2-8 parts of steel fiber; 8-15 parts of calcium sulfoaluminate; 1-3 parts of alkyl sulfonate; 1-4 parts of waterproofing agent; 10-15 parts of mineral admixture; Wherein, the cellulose ether is hydroxypropyl methylcellulose, and the polymer emulsion comprises the following raw materials in parts by weight: 20-50 parts of base monomer; 10-30 parts of comonomer; 0.5-2 parts of initiator; 0.5-3 parts of emulsifier; 1-5 parts of stabilizer; 0.1-1 parts of preservative; 0.1-1 parts of defoamer; appropriate amount of pH adjuster; The matrix monomer is composed of styrene, acrylic acid and methacrylic acid, wherein styrene is 10-30 parts; acrylic acid is 5-10 parts; methacrylic acid is 5-10 parts; The comonomer is butyl acrylate or methyl methacrylate; the initiator is potassium persulfate; the emulsifier is sodium dodecyl sulfate; the stabilizer is polyvinyl alcohol; the pH adjuster is sodium hydroxide or sodium acetate; Wherein, the polyacrylamide particles include the following raw materials in parts by weight: 80-99 parts of acrylamide, 1-20 parts of methacrylamide, 0.05-0.5 parts of ammonium persulfate, 0.1-1 parts of methylene bisacrylamide and 0.1-1 parts of hydroxyethyl cellulose; when preparing the polyacrylamide particles, acrylamide and methacrylamide weighed in parts by weight are dissolved in deionized water, ammonium persulfate is added under stirring, the temperature is controlled at 40-60° C., acrylamide and methacrylamide monomers are polymerized, methylene bisacrylamide and hydroxyethyl cellulose are added, the polymer forms a network structure, and the polymer solution is dried to obtain polyacrylamide particles.

2. The concrete anti-cracking and anti-seepage enhancer according to claim 1, characterized in that: The concrete anti-cracking and anti-seepage enhancer comprises the following raw materials in parts by weight: 4 parts of cellulose ether; 7.5 parts of polymer emulsion; 35 parts of cement; 7 parts of nano silicon dioxide; 2 parts of polyacrylamide particles; 2 parts of polyurethane; 5 parts of steel fiber; 11.5 parts of calcium sulfoaluminate; 2 parts of alkyl sulfonate; 2.5 parts of waterproofing agent; and 12.5 parts of mineral admixture.

3. The concrete anti-cracking and anti-seepage enhancer according to claim 2, characterized in that: The viscosity of the hydroxypropyl methylcellulose is in the range of 5000-200000 mPa·s; the degree of substitution is 1.2-2.0; the hydroxypropyl content is 4%-12%; the methoxy content is 19%-30%; the moisture content is ≤5%; and the pH value is 6-8.

4. The concrete anti-cracking and anti-seepage enhancer according to claim 3, characterized in that: The cellulose ether is prepared by mixing natural cellulose with a sodium hydroxide solution, performing an alkalization treatment, and mixing the alkalized cellulose with propylene oxide and methyl chloride for an etherification reaction, wherein the etherification reaction temperature is controlled at 50-80° C., and the etherification reaction replaces the hydroxyl groups on the cellulose molecules with methoxyl groups and hydroxypropyl groups to form hydroxypropyl methylcellulose; after the reaction is completed, the reaction mixture is neutralized with acetic acid, and washed with water for neutralization to obtain the cellulose ether, wherein the washed cellulose ether is dried to a water content of ≤5%.

5. A method for preparing the concrete anti-cracking and anti-seepage enhancer according to any one of claims 1 to 4, characterized in that: Here are the steps: 1) weighing cellulose ether, polymer emulsion, cement, nano-silica, polyacrylamide particles, polyurethane, steel fiber, calcium sulfoaluminate, alkyl sulfonate, waterproofing agent and mineral admixture according to weight parts for use; 2) adding cellulose ether and polyacrylamide particles into a mixer for premixing, and slowly adding polymer emulsion, stirring at a speed of 200-250 r / min, stirring for 10-15 minutes, and controlling the temperature at 25° C., then adding cement, and continuing stirring for 20-30 minutes to obtain a premix; 3) Slowly adding nano-silicon dioxide and polyurethane to the premix and continuing stirring for 10-15 minutes, and gradually adding steel fiber at a stirring speed of 150-200 r / min for 20-30 minutes, during which calcium sulphoaluminate is added to obtain a reinforced mixture; 4) Slowly add alkyl sulfonate waterproofing agent to the enhanced mixture, continue stirring at 200-250r / min for 5-10 minutes, finally add mineral admixture, continue stirring for 20-30 minutes until the mineral admixture is completely mixed, and obtain the final mixture based on concrete anti-cracking and anti-seepage enhancer, put it into a sealed container, and store it in a dry and cool place for use.

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