Environment-friendly polished dust-free floor concrete as well as preparation method and application thereof

Abstract

The invention relates to the technical field of building materials and terrace construction engineering, and discloses environment-friendly polished dust-free terrace concrete as well as a preparation method and application thereof, and a composite curing agent consisting of 5-15% of lithium silicate, 20-30% of a stabilizer, 1-5% of nano silicon dioxide, 5-10% of phase-change nano capsules, 1-3% of a slow-release chelating agent EDTA (Ethylene Diamine Tetraacetic Acid) and 0.5-2% of a functional additive is introduced in the preparation process of the concrete. The curing agent reacts with a cement hydration product in a concrete hardening process to generate a compact gel structure, so that the surface strength and compactness of concrete are improved; the phase change capsule can respond to mechanical disturbance or environment temperature rise in the using process, active components are released, and self-healing and densification of a surface layer structure are further promoted. The prepared terrace concrete has excellent compressive strength, wear resistance and surface hardness, remarkably inhibits flying dust in the later polishing or using process, and is green, environment-friendly and high in construction adaptability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building materials and floor construction engineering, and particularly relates to an environment-friendly polishing dust-free floor concrete as well as a preparation method and application thereof. BACKGROUND

[0002] The concrete floor is widely used in industrial plants, warehouse logistics, underground garages and large commercial spaces, and the mechanical properties, wear resistance and surface cleanliness of the concrete floor are directly related to the service life and environmental friendliness of the floor system. In the long-term use or later maintenance process, the surface of the floor is prone to produce micro-cracks, dust falling and surface strength degradation due to wear, impact or polishing, which not only affects the appearance and safety, but also increases the cleaning and maintenance cost.

[0003] In order to improve the above problems, the industry usually uses the method of spraying inorganic curing agent (such as sodium-based or lithium-based silicate) on the surface to enhance the surface performance of the concrete floor. Such materials form a dense structure by reacting with the cement hydration products, thereby improving the surface strength and impermeability. However, the traditional curing agent treatment method still has the following technical defects:

[0004] 1. The enhancement effect is limited to the surface layer, the reaction depth is limited, and it is difficult to maintain the strengthening structure for a long time;

[0005] 2. Dusting is still easy to occur during polishing, especially under the action of high-speed machinery, the pulverization phenomenon is obvious, which affects the construction environment and the health of personnel;

[0006] 3. It is difficult to realize the secondary reaction or self-healing function, the material lacks a responsive mechanism, and it cannot actively repair micro-cracks and stress concentration areas;

[0007] 4. Most surface treatment schemes are post-strengthening, which is disconnected with the concrete body, has poor integrity, and insufficient durability;

[0008] 5. The carbon footprint and VOC emission problems of the material have not been effectively controlled, and it is difficult to meet the requirements of green building development.

[0009] Therefore, there is an urgent need for a floor concrete product that is based on the concrete body, introduces enhancement function in the preparation stage of the concrete, and has good wear resistance, low dust emission and green environmental protection characteristics in the later period, to meet the engineering requirements of modern high performance, low maintenance cost and sustainable development. SUMMARY

[0010] The present application aims to provide an environment-friendly polishing dust-free floor concrete and its preparation method and application, so as to solve the problems of dusting, fast abrasion, poor surface density, short service life and the like of the existing floor concrete in use or maintenance. The present application introduces a reactivatable surface curing agent composition in the concrete preparation stage to form a dense concrete surface layer structure with initial reinforcement and later reactivity, so as to achieve the purpose of significantly improving the abrasion resistance, dust suppression capacity and overall service life of the concrete.

[0011] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0012] An environment-friendly polishing dust-free floor concrete is composed of the following raw materials by weight:

[0013] Water 150-160 parts,

[0014] P·O42.5 cement 230-240 parts,

[0015] S95 mineral powder 120-130 parts,

[0016] Machine-made sand 790-810 parts,

[0017] Gravel 1000-1040 parts,

[0018] Water reducing agent 7-9 parts,

[0019] Curing agent 12-16 parts;

[0020] The curing agent is added in the concrete mixing process, and is poured and formed as a whole with the concrete mixture and naturally maintained, participates in the cement hydration reaction and forms a dense C-S-H gel structure on the surface of the concrete;

[0021] The curing agent is composed of 5%-15% lithium silicate, 20%-30% stabilizer, 1%-5% nano silicon dioxide, 5%-10% phase change nano-capsule, 1%-3% slow-release chelating agent EDTA and 0.5%-2% functional additive;

[0022] The total solid content of the curing agent is 10%-15%; the composition pH value of the curing agent is 10-11, and the viscosity is 15-50 mPa・s.

[0023] As a preferred, the stabilizer in the curing agent is selected from one or more of water-soluble polymer stabilizers containing carboxyl or sulfonic acid functional groups and inorganic lithium salt complexing agents.

[0024] As a preferred, the water-soluble polymer stabilizer containing carboxyl or sulfonic acid functional groups includes polycarboxylic acid polyether, sodium polyacrylate and sodium butylene sulfonate.

[0025] As a preferred, the inorganic lithium salt complexing agent includes lithium carbonate, lithium nitrate and lithium sulfate.

[0026] As preferred, the nanosilica is a fumed product with a specific surface area of 180-220 m² / g, a particle size range of 10-20 nm, and a purity of ≥ 99.8%.

[0027] As preferred, the core material of the phase change nanocapsule is selected from one or more of hexadecane, decane or n-dodecane, the shell material is one or more of urea-formaldehyde resin, polyurea or polyurethane, the average particle size of the capsule is 100-300 nm, the coating rate is not less than 75%, and the phase change release temperature is set to be higher than the normal storage and construction environment temperature and lower than the friction temperature generated during the polishing process of the concrete floor surface, thereby having good storage stability and shear / thermal responsiveness.

[0028] As preferred, the functional aid is one or more of defoaming agent, retarder and penetration enhancer, and the total addition amount is 0.5%-2%.

[0029] An environmentally friendly preparation method of a polishing dust-free floor concrete, comprising preparation of a composite curing agent and preparation of the concrete;

[0030] The preparation of the composite curing agent comprises the following steps:

[0031] S1, main reaction base liquid preparation: mixing industrial lithium silicate and deionized water at a mass ratio of 1:1 to obtain a lithium silicate solution; then mixing the lithium silicate solution and a stabilizer at a mass ratio of 1:5, stirring for 5-10 min, and adjusting the pH value of the system to 10-11 by adding an alkaline adjusting agent, with the temperature being not higher than 30°C, to obtain the main reaction base liquid;

[0032] S2, nanofiller dispersion: slowly adding nanosilica powder into the main reaction base liquid under ultrasonic oscillation or high-speed shearing stirring, continuously stirring for more than 30 min, until the system is uniformly transparent;

[0033] S3, phase change capsule addition: slowly adding a phase change nanocapsule dispersion liquid prepared in advance using water and a surfactant into the system at 6% of the total mass of the system, and controlling the shearing intensity during stirring to prevent capsule rupture;

[0034] S4, slow-release component addition: adding 1%-3% of ethylenediaminetetraacetic acid (EDTA) as a slow-release chelating agent, slowly stirring for 5-10 min, and uniformly mixing the system;

[0035] S5, final adjustment and filtration: adding deionized water to a total solid content of 10%-15%, adjusting the viscosity of the system to 15-50 mPa·s, filtering through a 120-mesh filter, and then sealing and storing in a light-proof opaque plastic container;

[0036] S6, storage stability: the obtained composition can be stored stably at room temperature for more than 6 months, and the integrity rate of the nanocapsule is not less than 95%;

[0037] S7, preparation of concrete: water 150-160 parts, P·O42.5 cement 230-240 parts, S95 mineral powder 120-130 parts, machine-made sand 790-810 parts, gravel 1000-1040 parts, water reducing agent 7-9 parts, curing agent 12-16 parts; the concrete preparation process then includes the following stages:

[0038] (1) dry mixing stage: the cement, fine aggregate, coarse aggregate, 70% of the total water requirement and water reducing agent are added to the forced mixer according to the design proportion, and stirred for 30-60 seconds to make it preliminary uniform;

[0039] (2) liquid mixing stage: the prepared composite curing agent is diluted in the remaining 30% water in liquid form or added separately to the concrete mixture, and continues to stir for 60-120 seconds;

[0040] (3) homogenization stage: continue to stir for 60-120 seconds until the concrete mixture is uniform, without obvious agglomerates or free water, forming a concrete slurry with good workability;

[0041] (4) pouring and forming: the mixed concrete is used for floor pouring construction, and is vibrated, leveled and finished according to the specification;

[0042] (5) natural curing: curing for 7-28 days in an environment with a temperature of 20-30℃ and a relative humidity of ≥70%, to form a high-performance floor concrete material with dense structure, high strength and low dust during polishing.

[0043] As preferred, in step S1, the mass concentration of industrial lithium silicate is 20%-25%, and the pH value is in the range of 10-11; the stabilizer is a carboxylic acid type polymer complex stabilizer, and the addition ratio is 1 / 5 of the mass of lithium silicate solution, the reaction temperature is controlled to be not more than 30℃, and the stirring time is 5-10 min; the alkaline adjusting agent is 1 mol / L NaOH solution or 95% triethanolamine; preferably, the alkaline adjusting agent is 1 mol / L NaOH solution.

[0044] As preferred, in step S2, the nano filler is fumed nano silica powder with a particle size range of 10-20 nm and a specific surface area of 180-220 m² / g, and a purity of ≥99.8%; the nano silica is added to the main reaction base liquid obtained in step S1 in a slow addition manner, and dispersed for 30-45 min under the condition of ultrasonic wave or high-speed shearing stirring, to form a uniform transparent system.

[0045] As preferred, in step S3, the phase change nanocapsule is a microcapsule with hexadecane or paraffin as core material, urea-formaldehyde resin or polyurea as shell material, average particle size of 100-300 nm, coating rate of ≥75%, and phase change release temperature set to be higher than the normal storage and construction environment temperature and lower than the friction temperature generated in the polishing process of the concrete floor surface, with good storage stability and shear / thermal responsiveness. The capsule dispersion liquid is pretreated with a surfactant, the surfactant is a non-ionic polyoxyethylene ether, and the addition amount is 1%-2% of the mass of the capsule; the addition amount of the capsule is 6% of the total mass of the system; and the stirring speed is not more than 200 rpm, and the capsule is slowly added under low-speed stirring to avoid rupture.

[0046] As preferred, in step S4, the slow-release chelating agent is disodium ethylenediaminetetraacetate (EDTA-2Na) with a purity of ≥99% and in the form of white crystalline powder, and the addition amount is 1%-3% of the total mass of the system; and the functional additive is an organic silicon modified acrylic surface active liquid with a pH value of 5-7, and the addition amount is not more than 1% of the total mass of the system, and the system is uniform after stirring for 5-10 min.

[0047] As preferred, in step S5, the total solid content in the final composition is adjusted to 10-15 wt.%, and the viscosity of the system is controlled to be 15-50 mPa·s after adjustment to meet the use conditions of conventional spraying equipment; and a 120-mesh nylon screen is used for preliminary impurity removal in the filtration process, and the obtained liquid is packaged in an opaque plastic container and stored in a dark place.

[0048] As preferred, in step S6, the storage stability of the composition at 25 DEG C normal temperature environment can reach more than 6 months, the capsule integrity retention rate is not less than 95%, and the changes of the key indicators (viscosity, pH value, dispersibility) are not more than ±10%.

[0049] An application of an environmentally friendly polishing dust-free floor concrete, which is applied to industrial plants, warehouse logistics, commercial facilities, underground parking lots and other ground paving scenes with high requirements for wear resistance and dust-free environment.

[0050] The reaction principle of the application is as follows:

[0051] The action mechanism of the environmentally friendly polishing dust-free floor concrete system of the application is based on the two-stage reaction path of "primary reaction + friction activation" of the solidifying agent, and the continuous strengthening and re-densification of the surface structure of the concrete floor are realized through multi-component cooperation.

[0052] 1. Preliminary reaction mechanism of lithium silicate and cement hydration products

[0053] Lithium silicate (Li2SiO3) dissociates in aqueous solution to produce lithium ions (Li⁺) and silicate ions (SiO3²⁻). When it penetrates into the surface layer of concrete, it will react with a large amount of calcium hydroxide (Ca(OH)2) generated during the hydration of cement to form a dense calcium-silicate hydrate gel (C-S-H):

[0054] SiO3²⁻+Ca²⁺+H2O→C-S-H gel↓;

[0055] This C-S-H gel can seal capillary pores and improve the density and wear resistance of the concrete surface. At the same time, the small radius of lithium ions helps them penetrate deeply into the concrete pore structure and partially replace sodium and potassium ions, improving their resistance to alkali-aggregate reaction (ASR).

[0056] 2. Delayed release and activation of phase change nanocapsules

[0057] The phase change nanocapsule structure introduced in this invention uses a polyurethane / polyurea microcapsule shell to coat the core reactant (such as water glass solution, alkali metal salt, or reaction-promoting alkaline additive). This structure remains stable at ambient temperature, but is released when the core components are released due to local friction heating (40-70°C) or mechanical shear rupture during polishing.

[0058] Frictional heat during polishing triggers capsule rupture, releasing reactants such as water glass (Na2SiO3), which further reacts with unreacted Ca²⁺ and OH⁻ in cement to form secondary C-S-H gel layers, supplementing and strengthening the previous structure:

[0059] Na2SiO3+Ca(OH)2+H2O→C-S-H gel↓+NaOH↑;

[0060] The generated NaOH further increases the local pH, which helps to trigger the reaction of aluminum salt additives such as Al2(SO4)3) that may be present in the capsules to form calcium aluminate hydrate (C-A-H) gel, enhancing the chemical stability and density of the surface layer:

[0061] Al³⁺+Ca²⁺+H2O→C-A-H gel↓;

[0062] 3. Physical filling and interfacial strengthening of nanofillers

[0063] The added nano-silicon dioxide (SiO2) can adsorb Ca2+ and OH- as a reaction active site due to its extremely high specific surface area, and react with them to form a polymeric silica gel in an alkaline environment, thereby promoting the formation of C-S-H gel and enhancing the interfacial bonding strength. In addition, nano-SiO2 also has excellent physical filling effect, which can effectively fill the micro-pores in concrete, improve the overall structural density, and further inhibit the formation of water vapor permeation and carbonization path. In addition, there is a strong interfacial bonding force between the nano-filler and the reaction product, such as Si-O-Si, Al-O-Ca, etc. Bridge structure, further stabilizing the hardened layer.

[0064] 4. Regulation of reaction rhythm by slow-release chelating agent

[0065] The chelating agent (such as EDTA) has a reversible complexation reaction with free Ca2+, Mg2+ and other metal ions in the system, which temporarily slows down the reaction rate, avoiding the formation of clumps or agglomerates due to too fast initial reaction. At the same time, its complex release mechanism has certain responsiveness to temperature rise or shear triggering in the later period, which is helpful for "time release" or "activation response". When the local pH rises or is heated, the complex partially dissociates, releasing Ca2+ to participate in the reaction.

[0066] EDTA 4 -Ca2+ ⇌ [Ca-EDTA]2- (stable complex).

[0067] Compared with the prior art, the technical effects and advantages of the present application are:

[0068] (1) No obvious dust during polishing process, friendly to construction and use environment: by introducing a composite solidifying agent with active response mechanism into the concrete, the density and strength of the surface layer structure of the concrete are effectively improved, and the dust emission is significantly reduced during the polishing process of the floor use or maintenance, meeting the needs of green construction and high cleanliness scene;

[0069] (2) Surface hardness and wear resistance are greatly improved: the lithium silicate in the concrete and the cement hydration product generate dense C-S-H gel, combined with the physical filling effect of nano-filler and the secondary reaction mechanism of phase change capsule, the surface layer of the floor has excellent wear resistance and scratch resistance;

[0070] (3) Self-healing and strengthening ability, prolonging the service life: the phase change capsule breaks under the action of heat or shear stress in the later period, releasing the internal reactants, inducing the formation of secondary C-S-H / C-A-H gel, realizing the re-densification and self-repair of the micro-crack area, effectively delaying the damage development, and prolonging the service life of the floor;

[0071] (4) Green low carbon, life cycle environmental benefits are obvious: the curing agent of the application adopts water-based formula, no organic solvent, no VOC release; at the same time, the durability of concrete can be improved to reduce the frequency of later maintenance and repair, significantly reduce carbon emissions and resource consumption, and has good carbon emission reduction potential;

[0072] (5) Compatible with conventional concrete production process, strong adaptability: the composite curing agent can be directly mixed uniformly in the concrete mixing stage, the construction process is not changed, and it can adapt to the existing commercial concrete production line and pumping process, and has good engineering popularization and large-scale application foundation;

[0073] (6) Wide application range, meet the demand of high-performance floor in multiple scenarios: the concrete of the application is suitable for industrial plants, logistics warehouses, electronic workshops, underground garages and green buildings, and is especially suitable for high-performance floor systems with high requirements of "wear resistance + low dust + low maintenance". DETAILED DESCRIPTION

[0074] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0075] The embodiments and comparisons of the application are shown in Table 1, which are divided into two stages according to the research content, and the final invention content of the application is determined by various tests.

[0076] The embodiments and comparisons of the application are as follows:

[0077] I. Curing agent configuration determination

[0078] Embodiment 1

[0079] The embodiment provides an environment-friendly polishing dust-free floor concrete and a preparation method thereof,

[0080] S1, curing agent configuration:

[0081] (1) Main reaction base solution configuration

[0082] Take: 250g of industrial lithium silicate and 250g of deionized water, fully stir for 5min-10min, and get lithium silicate solution;

[0083] Take: 100g of carboxylic acid type polymer stabilizer, add to the lithium silicate solution, fully stir for 5min-10min. Then add 1-3ml of 1mol / L NaOH solution to adjust the pH of the system to 10.5, control the temperature not to exceed 30℃, and form the main reaction base solution.

[0084] (2) Nanofiller dispersion

[0085] Weighing: 10 g of fumed nano-silica is placed in a high-speed shearing mixer, heated to 50°C, and kept at this temperature for 1 h. The main reaction base liquid is mixed at a speed of 3000 rpm, and ultrasonic treatment (power 300 W) is performed simultaneously. The shearing and dispersion are continued for 30 min until the solution is uniformly transparent.

[0086] (3) Phase change capsule addition

[0087] Weighing: 60 g of phase change nano-capsules, 200 g of deionized water, and 1.2 g of polyoxyethylene ether surfactant. The phase change nano-capsules are dispersed in deionized water in advance, and the polyoxyethylene ether surfactant is added and stirred to form a milky white dispersion. The dispersion is slowly added to the main system under the condition that the stirring speed does not exceed 200 rpm, and stirred for 10 min to avoid capsule rupture.

[0088] (4) Slow-release component addition

[0089] Weighing: 20 g of EDTA-2Na powder. Add it to the system and stir slowly for 5-10 min to make it completely dissolved;

[0090] Weighing: 5 g of silicone-modified acrylic acid additive. Add it to the system and stir slowly for 5-10 min to make the system uniform.

[0091] (5) Final adjustment and filtration

[0092] Weighing: 53.8 g of deionized water. Adjust the total mass of the system to 1000 g, and the total solid content to about 12%. Detect the viscosity of the system and adjust it to 30 mPa·s (suitable for spraying). The obtained liquid is filtered through a 120 mesh nylon screen to remove large particle impurities, and then packed in a light-proof opaque plastic bottle and sealed.

[0093] (6) Storage stability

[0094] The composition is stored in a 25°C environment, and no sedimentation or stratification occurs within 6 months. The integrity rate of the nano-capsules remains above 95%, and the pH value and viscosity change within ±10%.

[0095] S2, concrete preparation

[0096] (1) Weigh 158 parts of water, 234 parts of P·O42.5 cement, 126 parts of S95 mineral powder, 800 parts of machine-made sand, 1032 parts of gravel, 8.3 parts of water reducing agent, and 14.4 parts of curing agent.

[0097] (2) Dry mixing stage: Add cement, fine aggregate, coarse aggregate, part of water (about 70% of the total water requirement) and water reducer into the forced mixer according to the designed proportion and stir for 30 to 60 seconds to make it initially uniform;

[0098] (3) Liquid mixing stage: Add the prepared composite curing agent in liquid form to the remaining water for dilution or add it separately to the concrete mixture and continue stirring for 60 to 120 seconds;

[0099] (4) Homogenization stage: Continue stirring for 60 to 120 seconds until the concrete mixture is uniform, without obvious agglomerates or free water, and a concrete paste with good workability is formed;

[0100] (5) Casting and molding: Use the mixed concrete for floor casting construction, and vibrate, level, finish and maintain according to the specifications;

[0101] (6) Natural curing: Curing for 7 to 28 days in an environment with a temperature of 20 to 30°C and a relative humidity of ≥70% will form a high-performance floor concrete material with a dense structure, high strength, and low dust generation during grinding.

[0102] Example 2

[0103] This embodiment provides an environmentally friendly polished dust-free floor concrete and a preparation method thereof.

[0104] The steps of this embodiment are the same as those of Example 1, except that the dosage of the curing agent components in S1 is: 200 g of industrial lithium silicate, 200 g of deionized water, 80 g of carboxylic acid polymer stabilizer, 8 g of nano-silica, 60 g of phase change nanocapsules, 1.2 g of non-ionic polyoxyethylene ether surfactant, 10 g of EDTA-2Na, 3 g of silicone-modified acrylic acid additive, and 437.8 g of deionized water replenisher.

[0105] Example 3

[0106] This embodiment provides an environmentally friendly polished dust-free floor concrete and a preparation method thereof.

[0107] The steps of this embodiment are the same as those of Example 1, except that the dosage of each component of the curing agent in S1 is: 300 g of industrial lithium silicate, 300 g of deionized water, 120 g of carboxylic acid polymer stabilizer, 15 g of nano-silica, 60 g of phase change nanocapsules, 1.2 g of non-ionic polyoxyethylene ether surfactant, 25 g of EDTA-2Na, 7 g of silicone-modified acrylic acid additive, and 171.8 g of deionized water replenisher.

[0108] Comparative Example 1

[0109] This comparative example provides an environmentally friendly polished dust-free floor concrete and a preparation method thereof.

[0110] The comparative example is different from example 1 in that it does not contain a nano-silica component, i.e. there is no step (2) in S1.

[0111] Comparative example 2

[0112] The comparative example provides an environmentally friendly polishing dust-free terrace concrete and a preparation method thereof,

[0113] The comparative example is different from example 1 in that it does not contain a phase change capsule component, i.e. there is no step (3) in S1.

[0114] Comparative example 3

[0115] The comparative example provides an environmentally friendly polishing dust-free terrace concrete and a preparation method thereof,

[0116] The comparative example is different from example 1 in that it does not contain an EDTA-2Na component, i.e. there is no step (4) in S1.

[0117] Comparative example 4

[0118] The comparative example provides an environmentally friendly polishing dust-free terrace concrete and a preparation method thereof,

[0119] The comparative example is different from example 1 in that it uses a traditional sodium-based hardening agent for comparison. The traditional hardening agent component: sodium silicate 10%, total solid content 12%.

[0120] II. Determination of the amount of hardening agent

[0121] Example 4

[0122] The example provides an environmentally friendly polishing dust-free terrace concrete and a preparation method thereof,

[0123] The example is the same as example 1 in steps, and the difference is that the amount of hardening agent of the concrete in S2 is 7.2 parts.

[0124] Example 5

[0125] The example provides an environmentally friendly polishing dust-free terrace concrete and a preparation method thereof,

[0126] The example is the same as example 1 in steps, and the difference is that the amount of hardening agent of the concrete in S2 is 21.6 parts.

[0127] Comparative example 5

[0128] The comparative example provides an environmentally friendly polishing dust-free terrace concrete and a preparation method thereof,

[0129] The comparative example is different from example 1 in that the concrete component in step S2 does not contain a hardening agent, and therefore there is no step S1.

[0130] Table 1 Comparison of raw material usage of each example and comparative example

[0131] Item group Curing agent component (key difference) Concrete raw materials (by weight fraction, common basis: water 150-160 parts, P・O42.5 cement 230-240 parts, S95 mineral powder 120-130 parts, machine-made sand 790-810 parts, gravel 1000-1040 parts, water reducing agent 7-9 parts) Curing agent content (parts) Example 1 Lithium silicate, carboxylic acid type polymer stabilizer, nano silicon dioxide, phase change nano capsule, EDTA-2Na, silicone modified acrylic aid Add the basic raw materials according to the standard proportion 14.4 Example 2 Lithium silicate (200g), carboxylic acid type polymer stabilizer (80g), nano silicon dioxide (8g), phase change nano capsule, EDTA-2Na (10g), silicone modified acrylic aid (3g) (total component dosage of curing agent is reduced compared to Example 1) Add the basic raw materials according to the standard proportion 14.4 Example 3 Lithium silicate (300g), carboxylic acid type polymer stabilizer (120g), nano silicon dioxide (15g), phase change nano capsule, EDTA-2Na (25g), silicone modified acrylic aid (7g) (total component dosage of curing agent is increased compared to Example 1) Add the basic raw materials according to the standard proportion 14.4 Example 4 Same as Example 1 curing agent component Add the basic raw materials according to the standard proportion 7.2 (reduced by 50% compared to Example 1) Example 5 Same as Example 1 curing agent component Add the basic raw materials according to the standard proportion 21.6 (increased by 50% compared to Example 1) Comparative Example 1 No nano silicon dioxide, the rest of the curing agent components are consistent with Example 1 Add the basic raw materials according to the standard proportion 14.4 Comparative Example 2 No phase change nano capsule, the rest of the curing agent components are consistent with Example 1 Add the basic raw materials according to the standard proportion 14.4 Comparative Example 3 No EDTA-2Na, the rest of the curing agent components are consistent with Example 1 Add the basic raw materials according to the standard proportion 14.4 Comparative Example 4 Use traditional sodium-based curing agent (sodium silicate 10%, total solid content 12%), without the composite components of Example 1 Add the basic raw materials according to the standard proportion 14.4 Comparative Example 5 No curing agent Add the basic raw materials according to the standard proportion 0

[0132] The performance tests are as follows:

[0133] The 28d compressive strength, abrasion loss, surface water absorption, surface Mohs hardness, dust-free performance and life cycle assessment of each example and comparative example were carried out.

[0134] Among them, the 28d compressive strength, abrasion loss, surface water absorption and other tests refer to the standard GB / T50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete"; the surface Mohs hardness test adopts Mohs hardness scratch method, that is, a group of standard hardness pens (hardness grade 1-10, corresponding to talc to diamond) are used to scratch the surface of the material in turn, and the hardness grade corresponding to the pen that can leave obvious scratches is observed, that is, the Mohs hardness of the measured material; the dust-free performance is the dust concentration raised by the concrete during surface grinding, which is detected by a PM2.5 / 10 detector; the carbon emissions generated during the preparation process of each example and comparative example are analyzed by using software SimaPro and based on Ecoinvent database. The test data is shown in Table 2;

[0135] Table 2 Performance test table of each example and comparative example

[0136] Item group Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 28d compressive strength (MPa) 55.1 50.9 52.1 44.6 48.2 44.0 45.1 41.5 44.2 37.0 45 cycles abrasion loss (kg·m 2 )]]> 0.8 0.9 0.9 1.2 1.1 2.1 2.2 1.9 1.9 3.2 Water absorption rate (%) 1.1 1.3 1.2 1.6 1.5 1.8 2.3 2.5 2.7 4.3 Surface Mohs hardness 7 6 6 5 7 5 6 6 4 4 Dust concentration during polishing (μg / m³) 85 100 96 160 140 205 211 199 190 390 Carbon emissions (kg / ton) 346 345 348 339 340 339 341 349 383 337

[0137] The data analysis is as follows:

[0138] After the incorporation of the composite curing agent in the examples, the 28d compressive strength of the concrete is significantly improved, among which the strengths of examples 1 and 3 reach 55.1 MPa and 52.1 MPa respectively, which are obviously better than that of blank comparative example 5 (37.0 MPa) without curing agent, and the improvement rates are 49% and 41% respectively. In the comparative example group, the strengths of comparative examples 1 without adding nano-silica, comparative example 2 without adding capsules, comparative example 3 without adding EDTA and comparative example 4 using sodium-based curing agent are all between 41.5-45.1 MPa, which are obviously lower than those of the examples, indicating that the components of the present application have a significant enhancement effect on the mechanical properties under the combined action.

[0139] The abrasion loss results show that the abrasion value of example 1 is 0.8 kg / m², which is much lower than that of comparative example 5 (3.2 kg / m²) and comparative example 1 (2.1 kg / m²), indicating that the composite curing agent of the present application can significantly improve the surface wear resistance of the floor concrete. Especially the synergistic effect of nano-filler and phase change capsules effectively strengthens the surface structure and improves the mechanical damage resistance.

[0140] The water absorption of the concrete after incorporating the solidifying agent in the examples is less than 1.6%, wherein the water absorption of example 1 is the lowest (1.1%), and the water absorption of comparative example 5 is as high as 4.3%, and the water absorption of the comparative example group is generally greater than 2%. It can be seen that the composite solidifying agent of the application effectively seals the capillary pores through the mechanisms of nano-filling, gelation reaction and structure densification, thereby improving the impermeability and durability of the concrete.

[0141] The surface Mohs hardness of example 1 and example 5 reaches grade 7, which is better than other groups, indicating that the solidifying agent of the application has a significant effect on improving the surface densification and scratch resistance. The comparative example group is generally not more than grade 6, the sodium-based solidifying agent comparative sample (comparative example 4) and the blank group (comparative example 5) are only grade 4, and the difference is obvious.

[0142] The dust concentration during polishing of the example is controlled between 85 and 140 μg / m³, which is significantly lower than that of comparative example 5 (390 μg / m³) and the traditional sodium-based comparative sample (comparative example 4, 190 μg / m³), fully indicating that the solidifying agent used in the application effectively suppresses the dust dispersion in the polishing process by enhancing the integrity and densification of the surface layer structure. The secondary reaction enhancement mechanism of the phase change capsule is particularly crucial for delaying damage and dust prevention.

[0143] The software simulation results show that the carbon emission of the solidifying agent of the application is controlled between 340 and 348 kg / ton, which is basically equivalent to that of the ordinary concrete comparative example 5 (337 kg / ton) without incorporating the solidifying agent, and is significantly better than that of the traditional sodium-based solidifying agent comparative example 4 (383 kg / ton). It indicates that although the composite reinforcing component is added in the application, the overall carbon footprint is well controlled due to the high activity of the system, the low dosage, and the reasonable water-based formulation, which meets the development direction of green building materials.

[0144] According to the analysis of the results of example 4 (reduced dosage) and example 5 (increased dosage), the dosage of the solidifying agent has a regulating effect on the performance. The strength, wear resistance and dust prevention performance of example 4 are slightly lower than those of example 1, while example 5 performs similarly to or even slightly better than example 1, indicating that appropriately increasing the dosage is effective in performance enhancement, but economic efficiency and carbon emission control need to be considered.

[0145] The test results show that the composite environmental protection solidifying agent designed in the application can significantly improve the mechanical properties, wear resistance, dust prevention ability and surface densification of the concrete floor, and has low carbon emission, which is better than the traditional sodium-based solidifying agent or the blank system. The key components (lithium silicate, nano-silicon dioxide, phase change capsule, EDTA, etc.) have a synergistic effect on the performance, which verifies the scientificity and practicability of the formulation of the application, and has good industrial promotion and application prospect.

[0146] 1、Traditional concrete floor is easy to produce a large amount of dust in the later maintenance grinding or long-term use due to the loose surface structure, which not only pollutes the environment, but also may cause respiratory diseases and other health problems. The invention introduces a composite solidifying agent in the preparation stage of concrete to solve the problem of dust from the root, and the lithium silicate in the solidifying agent reacts with the cement hydration product to generate dense C-S-H gel, which directly fills the surface capillary pores of concrete, reduces the surface porosity; nano-silicon dioxide further physically fills the micropores to form a double dense structure of "gel + nanoparticles", reducing the particle shedding during grinding; the active components are released by the phase change nano-capsule when the temperature rises during grinding and friction, and the secondary gel is generated to supplement the surface structure, avoiding dust due to local damage. Actual test shows that the dust concentration of the concrete of the invention during grinding is only 85-160 μg / m³ (Examples 1-5), which is far lower than that of traditional concrete (390 μg / m³) and traditional sodium-based solidifying agent treated concrete (190 μg / m³), and can meet the needs of high cleanliness scenes such as industrial plants and electronic workshops.

[0147] 2、The traditional concrete floor is easy to appear sanding and wear after long-term use due to the insufficient surface strength, which affects the service life. The invention significantly improves the surface mechanical properties through the synergistic effect of multiple components: the C-S-H gel generated by lithium silicate and cement hydration is the core carrier of concrete strength, which can improve the surface compressive strength; the gas phase nano-silicon dioxide (specific surface area 180-220 m² / g) can promote gel generation by adsorbing Ca²⁺ in cement due to its high activity, and its nanoscale can enhance the interfacial bonding force between gel and aggregate; the active components released by the phase change capsule can generate C-S-H / C-A-H gel in the wear or grinding area, dynamically supplementing the wear-resistant layer. Performance test shows that the 28d compressive strength of the concrete of the invention is 50.9-55.1 MPa (Examples 1-3), the 45-cycle abrasion loss is only 0.8-0.9 kg / m², and the surface Mohs hardness is 6-7 grade, which is far superior to the blank control group (compressive strength 37.0 MPa, abrasion 3.2 kg / m², hardness 4 grade), and can withstand long-term rolling and high-frequency friction of heavy machinery.

[0148] 3. Traditional curing agents can only achieve "one-time reinforcement" and cannot cope with structural damage caused by later wear and tear. The present application innovatively introduces a "responsive self-healing mechanism": the phase change temperature of the phase change nano-capsule is designed to be "higher than the storage / construction temperature and lower than the polishing friction temperature" (such as 40-70℃), which remains stable during normal use and only breaks down when polishing or local overheating occurs; the components released by the capsule, such as water glass, and the unreacted cement components generate C-S-H gel again, filling in micro-cracks or worn areas; the slow-release chelating agent EDTA can delay the initial reaction rate, leaving some unreacted active components to ensure sufficient reactants for later self-healing. This dual mechanism of "initial reinforcement + later self-healing" enables the floor to dynamically repair damage during long-term use. Comparative tests show that the wear amount of Comparative Example 2 without phase change capsules is 2.2 kg / m², which is significantly higher than that of Example 1 containing capsules (0.8 kg / m²), proving the role of the self-healing mechanism in improving wear resistance.

[0149] 4. While improving performance, the present application also considers the environmental friendliness of the material throughout its life cycle: the curing agent uses a water-based formulation without the addition of organic solvents, avoiding VOC emissions; the preparation process does not require high temperature and high pressure, with low energy consumption; high wear resistance and self-healing ability reduce the frequency of floor renovation, reducing the consumption of materials (such as cement, sand) and construction energy consumption for later repair; compared with traditional sodium-based curing agents (carbon emissions of 383 kg / ton), the carbon emissions of the curing agent of the present application are only 340-348 kg / ton, close to that of blank concrete (337 kg / ton), and due to the extended service life, the carbon emissions throughout the life cycle can be further reduced. In addition, the curing agent can be stored stably at room temperature for more than 6 months (nano-capsule integrity rate ≥95%), reducing material waste during storage and meeting the green building concept of low carbon and high efficiency.

[0150] 5. Traditional surface curing agents need to be sprayed after concrete pouring, increasing construction procedures and costs, and are easily affected by construction environment (such as temperature, humidity). The curing agent of the present application can be directly incorporated into the existing concrete production process: the curing agent is added in liquid form during the concrete mixing stage, without the need to change the existing "dry mixing-liquid mixing-homogenization" production process of commercial concrete; the viscosity of the curing agent is controlled at 15-50 mPa・s, which can be uniformly mixed with the concrete mixture without affecting the construction operations such as pouring and vibrating; only 7-28 days of curing is required in a natural environment with a temperature of 20-30℃ and a humidity of ≥70%, without the need for special curing equipment, which is suitable for most construction site scenarios. This "mix and use" feature can directly interface with existing concrete mixing stations and construction systems, reducing promotion costs and being suitable for large-scale applications.

[0151] 6. The concrete of the present application can cover a variety of high-demand scenarios due to its comprehensive advantages of "wear resistance, dust-free, environmental protection, and strong adaptability":

[0152] Industrial plants: They can withstand the impact of heavy equipment and wear from material handling, and their low dust emission characteristics meet the cleanliness standards of workshops.

[0153] Warehousing and logistics: Withstands high-frequency reciprocating friction from forklifts, the wear-resistant layer is not easily damaged, and reduces the impact of ground maintenance on logistics efficiency;

[0154] Underground parking lot: High compressive strength can bear the weight of vehicles, and low water absorption rate (1.1% to 1.6%) can reduce sanding caused by groundwater infiltration;

[0155] Commercial facilities: The surface has a Mohs hardness of 6-7 and strong scratch resistance, which can maintain long-term beauty and reduce the frequency of renovation.

[0156] Compared with traditional floor materials, the present invention does not require adjustment of the core formula for different scenarios. It can adapt to the needs by only fine-tuning the dosage of the curing agent, and has the flexibility of multiple uses of one material.

[0157] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly polished dust-free floor concrete, characterized in that: It is composed of the following raw materials in parts by weight: 150-160 parts water, PO42.5 cement 230-240 parts, 120-130 parts of S95 mineral powder, 790-810 parts of machine-made sand, 1000-1040 parts of crushed stone, 7-9 parts of water reducing agent, 12-16 parts of curing agent; The curing agent is added during the concrete mixing process, cast and formed with the concrete mixture as a whole and naturally cured, participating in the cement hydration reaction and forming a dense CSH gel structure on the concrete surface; The curing agent is composed of 5% to 15% lithium silicate, 20% to 30% stabilizer, 1% to 5% nano silicon dioxide, 5% to 10% phase change nano capsule, 1% to 3% slow-release chelating agent EDTA and 0.5% to 2% functional additives; The total solid content of the curing agent is 10% to 15%; the pH value of the curing agent composition is 10 to 11, and the viscosity is 15 to 50 mPa·s.

2. The environmentally friendly polished dust-free floor concrete according to claim 1, characterized in that: The stabilizer in the curing agent is selected from one or more of a water-soluble polymer stabilizer containing a carboxyl or sulfonic acid functional group and an inorganic lithium salt complexing agent.

3. The environmentally friendly polished dust-free floor concrete according to claim 2, characterized in that: Water-soluble polymer stabilizers containing carboxyl or sulfonic acid functional groups include polycarboxylic acid polyether, sodium polyacrylate, and sodium polybutene sulfonate.

4. The environmentally friendly polished dust-free floor concrete according to claim 3, characterized in that: Inorganic lithium salt complexing agents include lithium carbonate, lithium nitrate, and lithium sulfate.

5. The environmentally friendly polished dust-free floor concrete according to claim 1, characterized in that: Nano-silicon dioxide is a product produced by the gas phase method, with a specific surface area of ​​180-220m² / g, a particle size range of 10-20nm, and a purity of ≥99.8%.

6. The environmentally friendly polished dust-free floor concrete according to claim 1, characterized in that: The core material of the phase change nanocapsule is selected from one or more of hexadecane, decane or n-dodecane, the shell material is one or more of urea-formaldehyde resin, polyurea or polyurethane, the average particle size of the capsule is 100-300nm, the coverage rate is not less than 75%, and the phase change release temperature is set to be higher than the normal storage and construction environment temperature and lower than the friction heating temperature generated during the grinding process of the concrete floor surface.

7. The environmentally friendly polished dust-free floor concrete according to claim 1, characterized in that: The functional additives are one or more of defoaming agents, retarders and penetration enhancers, with a total amount of 0.5% to 2%.

8. A method for preparing the environmentally friendly polished dust-free floor concrete according to any one of claims 1 to 7, characterized in that: Including the preparation of composite curing agent and the preparation of concrete; The preparation of the composite curing agent comprises the following steps: S1. Preparation of the main reaction base liquid: industrial lithium silicate and deionized water are mixed in a mass ratio of 1:1 to obtain a lithium silicate solution; the lithium silicate solution is then mixed with a stabilizer in a mass ratio of 1:5, stirred for 5 to 10 minutes, and an alkaline regulator is added to control the pH value of the system to 10 to 11 and the temperature not to exceed 30° C. to obtain the main reaction base liquid; S2. Nanofiller dispersion: Slowly add nanosilica powder to the main reaction base liquid under ultrasonic oscillation or high-speed shear stirring conditions, and continue stirring for more than 30 minutes until the system becomes uniform and transparent; S3. Adding phase change capsules: slowly add the phase change nanocapsule dispersion prepared in advance using water and surfactant into the system at 6% of the total mass of the system. Control the shear strength during stirring to prevent the capsules from breaking. S4. Adding the slow-release component: Add 1% to 3% by mass of ethylenediaminetetraacetic acid (EDTA) as a slow-release chelating agent and stir slowly for 5 to 10 minutes until the system is uniform; S5. Final preparation and filtration: Add deionized water to a total solid content of 10% to 15%, adjust the system viscosity to 15 to 50 mPa·s, filter through 120 mesh, and seal in a light-proof opaque plastic container for storage; S6. Storage stability: The obtained composition can be stably stored at room temperature for more than 6 months, and the integrity rate of the nanocapsules is not less than 95%; The preparation of concrete includes the following steps: (1) Dry mixing stage: Add cement, fine aggregate, coarse aggregate, 70% of the total water requirement and water reducer into the forced mixer according to the designed proportion and stir for 30 to 60 seconds to make it initially uniform; (2) Liquid mixing stage: Add the prepared composite curing agent in liquid form to the remaining 30% of water for dilution or add it separately to the concrete mixture and continue stirring for 60 to 120 seconds; (3) Homogenization stage: Continue stirring for 60 to 120 seconds until the concrete mixture is uniform, with no obvious agglomerates or free water, and a concrete paste with good workability is formed; (4) Casting and forming: Use the mixed concrete for floor casting construction, and vibrate, level and finish according to the specifications; (5) Natural curing: Curing for 7 to 28 days in an environment with a temperature of 20 to 30°C and a relative humidity of ≥70%.

9. The method for preparing an environmentally friendly polished dust-free floor concrete according to claim 8, characterized in that: In step S1, the mass concentration of lithium silicate is 20% to 25%, the pH value range is 10 to 11; the alkaline regulator is 1 mol / L NaOH solution or 95% triethanolamine; In step S3, the surfactant is a nonionic polyoxyethylene ether, and the added mass is 1% to 2% of the capsule mass; the stirring speed does not exceed 200 rpm.

10. An application of the environmentally friendly polished dust-free floor concrete according to any one of claims 1 to 7, characterized in that: The environmentally friendly polished dust-free floor concrete is used in ground paving scenarios such as industrial plants, warehousing and logistics, commercial facilities, and underground parking lots that require wear resistance and a dust-free environment.