CN116553858B

CN116553858B - Low-carbon concrete additive and preparation method and application thereof

Info

Publication number: CN116553858B
Application number: CN202310810657.3A
Authority: CN
Inventors: 张祖华; 李镓睿; 倪阳; 周正宁; 方沿
Original assignee: Hunan Ningying New Material Technology Co ltd
Current assignee: Hunan Ningying New Material Technology Co ltd
Priority date: 2023-07-04
Filing date: 2023-07-04
Publication date: 2023-09-05
Anticipated expiration: 2043-07-04
Also published as: CN116553858A

Abstract

The application provides a preparation method of a low-carbon concrete additive, which comprises a component A and a component B, wherein the component A is prepared from 24-36 parts of aluminate cement, 8-12 parts of limestone powder, 8-12 parts of mineral powder, 0.8-1.2 parts of liquid sodium silicate and 20-30 parts of water, the component B is prepared from 4-6 parts of tribromomethyl methacrylate, 16-24 parts of p-bromophenylallyl alcohol polyoxyethylene ether, 0.8-1.2 parts of ammonium persulfate, 0.8-1.2 parts of mercaptoethanol, 24-36 parts of water and 9-12 parts of hanging white block solution, and the low-carbon concrete additive prepared by the method comprises composite crystal nucleus spherical particles and a high-molecular surfactant which can be used for accelerating the formation of C-S-H and other gels under the synergistic action, so that the consumption of 50% of cement in concrete can be reduced, and the carbon emission and cost of the concrete can be reduced. The application also provides the low-carbon concrete additive prepared by the method and the low-carbon concrete.

Description

Low-carbon concrete additive and preparation method and application thereof

Technical Field

The application relates to the technical field of building materials, in particular to a low-carbon concrete additive, a preparation method and application thereof.

Background

Cement concrete is the most dominant building material at present, the consumption is the largest, and cement concrete production is the traditional energy consumption. The carbon dioxide emission in the cement concrete industry is inferior to that in the electric power and steel industry, and accounts for about 13.5% of the total carbon dioxide emission in the whole country.

In cement concrete, the most predominant source of carbon dioxide is in the production of cement. The cement production process mainly comprises links of raw material preparation, clinker calcination, cement preparation and the like, and a large amount of energy sources are consumed in the production process, and the energy sources account for about 90% of the total carbon dioxide emission of the concrete, so that the carbon dioxide emission can be reduced by reducing the cement consumption in the cement concrete.

The prior art reduces the cement consumption of concrete, generally adopts concrete additives such as synergists, reinforcing agents and the like, and often has the problems of higher cost, low economic benefit or less cement consumption.

Disclosure of Invention

The application aims to provide a low-carbon concrete additive, a preparation method thereof and low-carbon concrete so as to solve at least one technical problem. The application achieves the above object by the following technical scheme.

In a first aspect, the application provides a method for preparing a low carbon concrete additive, comprising:

uniformly mixing a component A and a component B, wherein the preparation method of the component A comprises the following steps: weighing 24-36 parts of aluminate cement, 8-12 parts of limestone powder, 8-12 parts of mineral powder, 0.8-1.2 parts of liquid sodium silicate and 20-30 parts of water according to parts by weight, adding the materials into a stirring kettle, fully stirring, standing for 36-48 hours at 80+/-5 ℃ under the environment with the humidity of 95-100%, drying at 70-90 ℃, and grinding to obtain the component A;

the preparation method of the component B comprises the following steps: weighing 4-6 parts by weight of methyl tribromomethacrylate, 16-24 parts by weight of p-bromophenyl allyl alcohol polyoxyethylene ether, 0.8-1.2 parts by weight of ammonium persulfate, 0.8-1.2 parts by weight of mercaptoethanol and 24-36 parts by weight of water, uniformly mixing to obtain a mixed solution, and uniformly dripping 9-12 parts by weight of a white suspending block solution into the mixed solution to obtain the component B.

In one embodiment, the weight ratio of the component A to the component B is 1:2-2:1.

In one embodiment, the liquid sodium silicate has a modulus of 1.2 to 1.5.

In one embodiment, the liquid sodium silicate has a solids content of 40-60%.

In one embodiment, the component A has a Bosch specific surface area of greater than 600m ² /kg。

In one embodiment, the molecular weight of the p-bromophenyl allyl alcohol polyoxyethylene ether is 2000-3000.

In one embodiment, the weight fraction of the hanging white block solution is 5%.

In one embodiment, the method for preparing component B further comprises: uniformly dripping 10 parts by weight of the white suspending block solution into the mixed solution within 90-120 min.

In a second aspect, the application provides a low carbon concrete additive prepared by the preparation method of the low carbon concrete additive in the first aspect.

In a third aspect, the present application provides a low carbon concrete comprising: water, cement, fly ash, mineral powder, sand, crushed stone, an admixture and the low carbon concrete additive of the second aspect, the low carbon concrete additive being used to reduce the amount of cement in the low carbon concrete.

The low-carbon concrete additive prepared by the preparation method comprises composite crystal nucleus spherical particles composed of hydrated calcium aluminate, C-A-S-H gel and N-A-S-H gel and se:Sub>A high-molecular surfactant, and the synergistic effect of the composite crystal nucleus spherical particles and the high-molecular surfactant can accelerate the formation of C-S-H gel and other gels in the concrete, so that the consumption of 50% of cement in the concrete can be reduced to the maximum extent, the material cost of the concrete is reduced, and the durability of the concrete is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows an SEM image of the concrete slurry of example 1 of the present application at a magnification of 3 ten thousand times.

Fig. 2 shows an SEM image of the concrete slurry of comparative example 1 of the present application at a magnification of 3 ten thousand times.

Fig. 3 shows a comparative graph of the concrete block of example 1 (left) according to the present application and the concrete block of comparative example 1 (right).

Fig. 4 shows an SEM image of the low carbon concrete additive component a of the present application at 1 ten thousand magnification.

Fig. 5 shows an infrared spectrum of the low carbon concrete additive component B of the present application.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present application and are not to be construed as limiting the present application.

In order to make the technical solution of the present application better understood by those skilled in the art, the following description will be made in detail and complete with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the application. All other embodiments, based on the embodiments of the application, which a person skilled in the art would obtain without making any inventive effort, are within the scope of the application.

The embodiment of the application provides a preparation method of a low-carbon concrete additive, which comprises the following steps: the preparation method of the component A comprises the following steps of: weighing 20-38 parts of aluminate cement, 8-15 parts of limestone powder, 8-15 parts of mineral powder, 0.5-2 parts of liquid sodium silicate and 20-30 parts of water according to parts by weight, adding into a stirring kettle, fully stirring, standing for 36-48h at 80+/-5 ℃ and in an environment with the humidity of 95% -100%, drying at 70-90 ℃, and grinding to obtain a component A, wherein the modulus of the liquid sodium silicate is 1.2-1.5, and the solid content of the liquid sodium silicate is 40-60%. Further, it is preferable that 24 to 36 parts of aluminate cement, 8 to 12 parts of limestone powder, 8 to 12 parts of mineral powder, 0.8 to 1.2 parts of liquid sodium silicate, and 20 to 30 parts of water.

The preparation method of the component B comprises the following steps: weighing 4-6 parts by weight of methyl tribromomethacrylate, 16-24 parts by weight of p-bromophenyl allyl alcohol polyoxyethylene ether, 0.5-2 parts by weight of ammonium persulfate, 0.5-2 parts by weight of mercaptoethanol and 24-36 parts by weight of water, uniformly mixing to obtain a mixed solution, uniformly dripping 8-15 parts by weight of a white suspending block solution into the mixed solution, and keeping stirring the mixed solution in the dripping process to obtain the component B, wherein the molecular weight of the bromophenyl allyl alcohol polyoxyethylene ether is 2000-3000. Further, it is preferable that the solution contains 0.8 to 1.2 parts of ammonium persulfate, 0.8 to 1.2 parts of mercaptoethanol, 24 to 36 parts of water and 9 to 12 parts of a weight solution.

The component A is se:Sub>A composite crystal nucleus of hydrated calcium carbonate, C-A-S-H gel and N-A-S-H gel, the two gels coat the hydrated calcium carbonate in layers, and multi-layer coated spherical particles containing the hydrated calcium carbonate can be obtained during ball milling. The particles play a role of efficient crystal nucleus in the concrete, and accelerate the formation process of gel such as C-S-H, C-A-S-H in the concrete.

The following is a reaction equation for the synthesis of component B:

in the synthesis process of the component B, two monomers are subjected to polyaddition by a free radical polymerization reaction initiated by oxidation reduction to form a high molecular compound. The compound has larger heads, including p-bromophenyl and tribromomethyl, and generates larger steric hindrance, so that the compound is not easy to be directly absorbed into pores by charges of the compound to fail when the compound interacts with cement particles.

The low-carbon concrete additive prepared by the preparation method of the low-carbon concrete additive provided by the embodiment of the application comprises composite crystal nucleus spherical particles composed of hydrated calcium carbonate, C-A-S-H gel and N-A-S-H gel and se:Sub>A high-molecular surfactant, and the synergistic effect of the composite crystal nucleus spherical particles and the high-molecular surfactant can accelerate the formation of C-S-H gel and the like in concrete, so that the consumption of 50% of cement in the concrete is reduced at the highest energy efficiency, the material cost of the concrete is reduced, and the durability of the concrete is improved.

It will be appreciated that certain weight errors are allowed when the components a and B are prepared from the materials in the respective weight ratios, and that the performance indexes of the low carbon concrete additive prepared by the preparation method and the concrete using the low carbon concrete additive are not affected. In the milling step for preparing component A, milling may be carried out by a ball mill to obtain a uniform powdery component A having a Bosch specific surface area of more than 600m ² /kg。

The application provides a low-carbon concrete additive, which is prepared by a preparation method of the low-carbon concrete additive.

The application provides a low-carbon concrete, comprising: the low-carbon concrete additive is used for reducing the consumption of cement in low-carbon concrete, reducing the consumption of 50% of cement in the concrete with highest energy efficiency, and greatly reducing the material cost and carbon dioxide emission of the concrete.

In the concrete using the additive, the low-carbon concrete additive accounts for about 0.5-1.5% of the mass of the concrete, the cement consumption in the concrete can be reduced by 30-50%, the proportion of other components can be increased by equal amount to supplement the missing cement volume, and the water-cement ratio can be adjusted by referring to the concrete without the low-carbon concrete additive.

The technical scheme of the application is further described by the following specific embodiments. The chemical reagents used in the examples were all analytically pure, and the concrete raw materials used were all from the company longsand, tianshui concrete, inc. The parts indicated in the examples are parts by weight.

Example 1

Preparation of low-carbon concrete:

uniformly mixing 1.7 parts of component A and 1.7 parts of component B, adding concrete within 30min, and uniformly stirring, wherein the concrete comprises 153 parts of water, 90 parts of cement, 130 parts of fly ash, 120 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of additive;

preparation of low-carbon concrete additive:

the preparation method of the component A comprises the following steps: weighing 30 parts of aluminate cement, 10 parts of limestone powder, 10 parts of mineral powder, 1 part of liquid sodium silicate and 25 parts of water, adding into a stirring kettle, fully stirring, standing for 48 hours at 80 ℃ in a humidity 95% environment, drying at 80 ℃, and grinding to obtain a component A, wherein the modulus of the liquid sodium silicate is 1.3, and the solid content of the liquid sodium silicate is 50%.

The preparation method of the component B comprises the following steps: 5 parts of tribromomethyl methacrylate, 20 parts of p-bromophenyl allyl alcohol polyoxyethylene ether, 1 part of ammonium persulfate, 1 part of mercaptoethanol and 30 parts of water are weighed and uniformly mixed to obtain a mixed solution, 10 parts of a weight percent 5% weight part of a white suspending block solution is uniformly dripped into the mixed solution within 100min, and the mixed solution is kept stirring in the dripping process to obtain the component B.

Example 2

This example differs from example 1 only in that the concrete comprises 153 parts water, 120 parts cement, 110 parts fly ash, 110 parts mineral powder, 895 parts sand, 1025 parts crushed stone and 7.5 parts admixture.

Example 3

This example differs from example 1 only in that 2.27 parts of component a and 1.13 parts of component B are uniformly mixed, and concrete is added in 30 minutes and uniformly stirred, wherein the concrete comprises 157 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an additive.

Example 4

This example differs from example 1 only in that 1.13 parts of component a and 2.27 parts of component B are uniformly mixed, and concrete is added in 30 minutes and uniformly stirred, wherein the concrete comprises 156 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an additive.

Example 5

This example differs from example 1 only in that in the preparation method of component B, 4 parts of methyl tribromomethacrylate is weighed, and the concrete comprises 155 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an additive.

Example 6

This example differs from example 1 only in that in the preparation method of component a, 0.8 part of liquid sodium silicate is weighed, and the concrete comprises 160 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an additive.

Comparative example 1

The comparative example differs from example 1 only in that no low carbon concrete additive was added, the concrete comprising 170 parts water, 180 parts cement, 110 parts fly ash, 110 parts mineral powder, 895 parts sand, 1025 parts crushed stone and 7.5 parts admixture.

Comparative example 2

The comparative example differs from example 1 only in that only 3.4 parts of component a was added, and no component B was added, and concrete comprising 147 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an additive was added within 30 minutes and stirred uniformly.

Comparative example 3

The comparative example differs from example 1 only in that only 3.4 parts of component B was added, component a was not added, and concrete comprising 153 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an additive was added within 30 minutes and stirred uniformly.

Comparative example 4

This comparative example differs from example 1 only in that in the preparation method of component B, 2 parts of methyl tribromomethacrylate is weighed, and the concrete comprises 165 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an admixture.

Comparative example 5

The comparative example differs from example 1 only in that in the preparation method of component a, no liquid sodium silicate was added, and the concrete comprised 165 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of admixture.

Comparative example 6

The comparative example differs from example 1 only in that in the preparation method of component a, limestone powder was not added, and the concrete included 153 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone, and 7.5 parts of an admixture.

Comparative example 7

This comparative example differs from example 1 only in that in the preparation method of component B, methyl tribromomethacrylate is replaced with methyl methacrylate, and the concrete comprises 153 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an admixture.

Comparative example 8

The comparative example differs from example 1 only in that no low carbon concrete additive was added, the concrete comprising 147 parts of water, 120 parts of cement, 110 parts of fly ash, 110 parts of mineral powder, 895 parts of sand, 1025 parts of crushed stone and 7.5 parts of an additive.

Measuring the compressive strength of each group of concrete at each age according to GB/T50081-2019 Standard of test method for physical and mechanical properties of concrete; the durability of the concrete is measured according to GB/T50082-2016 Standard for test methods for Long-term Performance and durability of common concrete, wherein a step-by-step pressurizing method is adopted in the impermeability test. The cement reduction ratio was calculated from each group relative to comparative example 1, comparative example 1 being the ratio of conventional C30 grade concrete. The test results are shown in the following table:

list one

According to the national standard, the 28d compressive strength of C30 concrete is not lower than 30MPa, and in addition, 15% strength is rich (namely, the C30 concrete is generally not lower than 34.5 MPa). As can be seen from the above examples and comparative examples, the concrete provided with the low carbon concrete additive applied according to the present application can generally save significantly higher proportion of cement and obtain better mechanical properties and durability of the concrete, and the more excessive strength also indicates that there is still room for further reduction of the amount of cement used; meanwhile, the low-carbon concrete also has higher durability.

The carbon emission of the cement accounts for more than 90% of the total carbon emission of the concrete, so that the reduction of the cement consumption is the reduction of the carbon emission of the concrete, and the reduction of the cement consumption by 50% is the reduction of the carbon emission of the concrete by nearly half. Referring to fig. 1 and 2 together, the concrete of example 1 is a cement slurry with high compactness, while the concrete of comparative example 1 is a cement slurry with relatively crushed pores and low compactness. Example 1 only 50% of the cement of comparative example 1 was used, and the concrete of example 1 exhibited significantly higher strength and better durability. Therefore, the method for manufacturing the low-carbon concrete provided by the application is effective. With continued reference to fig. 3, in example 1, the amount of cement is reduced, and the amount of other light-colored materials such as mineral powder is increased, so that the left low-carbon concrete block has lighter overall color and is more attractive than the right concrete block of comparative example 1.

From examples 1 and 2, it can be analyzed that: after the low-carbon concrete technology is adopted, the cement consumption is reduced by 33 percent and the technical effect is similar to that of reducing by 50 percent, but the strength and the durability of the concrete with the multipurpose cement are still slightly better than those of the concrete with the less multipurpose cement. Because the cement is too small, the data of the comparative examples are too different and lose comparability, and the same cement dosage as that of the example 2 is adopted in the comparative examples.

As can be seen from examples 3 and 4, the strength and durability of the concrete are reduced when the addition ratio of the component A and the component B deviates from 1:1, but the reduction is still acceptable when the ratio of the component A and the component B falls within the range of 1:2 to 2:1.

As is evident from comparative examples 2 and 3, the components A and B must act synergistically, and the absence of either component will also result in a low carbon concrete having a strength which does not meet the corresponding specifications.

From examples 5, 6 and comparative examples 4, 5, it can be seen that sodium silicate and methyl tribromomethacrylate play an important role in both component A and component B, respectively, and that a reduction or no addition beyond the viable range results in a complete failure to achieve the intended technical effect. In combination with comparative example 6, it is clear that three components, namely methyl tribromomethacrylate, sodium silicate and limestone, are all components necessary for the system, and the three components exist cooperatively, which is not essential. Comparative examples 5 and 6 also demonstrate that the lack of sodium silicate lacks N-A-S-H gel and the lack of limestone lacks hydrated calcium carbonate nuclei, which must act simultaneously to actually serve the function of the composite nuclei.

Comparative example 7 provides a solution using methyl acrylate instead of methyl tribromomethacrylate, and as can be seen from the implementation data, the effect of using methyl acrylate is significantly worse than that of using methyl tribromomethacrylate, probably because methyl acrylate has been adsorbed by cement particles or mud powder in the concrete before the cement paste hardens due to the absence of umbrella-shaped tail, resulting in a decrease in various properties of the concrete.

Comparative example 8 provides a comparative example in which no additives were added, and it can be seen that the concrete exhibited poorer properties than the other comparative examples.

Referring to fig. 4, component a retains a more spherical, granular structure with more surface pores and a portion of the spherical inner wrap exposed. Wherein the component which obviously presents prismatic particles is hydrated calcium carbonate, and the outer layer part of the sphere coating is C-A-S-H gel or N-A-S-H gel. Meanwhile, due to the high dispersibility of the crystal nuclei, the gel forming process of the concrete C-S-H and the like is more uniform, so that the compactness of the concrete is higher, the hardening strength of the cement is increased, and the same strength can be achieved by using less cement.

In addition, the spherical particles of component A are significantly different from the common single C-S-H crystal nuclei or calcium carbonate crystal nuclei, which are only suitable for the crystallization induction of similar components, for example, C-S-H gel crystal nuclei generally induce only the formation of C-S-H gel, calcium carbonate crystal nuclei generally induce only the formation of calcium hydroxide, hydrated calcium sulfoaluminate, and crystals tend to grow from their surfaces. The composite crystal nucleus formed by the low-carbon concrete additive prepared by the preparation method provided by the application has hydrated calcium carbonate, C-A-S-H gel, N-A-S-H gel and other components, and the mutual wrapping relation among the components can lead the components to simultaneously induce the generation of various minerals such as C-S-H gel, C-A-S-H gel, ettringite, hydrated tetracalcium iron aluminate and the like in the cement hydration process.

Because the component A only provides hydration time of 48 hours, the spherical particles are not completely packed, and gaps in the spherical particles can be penetrated by gel induced by the particles, so that the mutual overlapping of cement particles is accelerated and enhanced. The incompletely compact package leads to the exposure of the internal hydrated calcium carbonate crystal nucleus, and plays a role of a composite crystal nucleus together with the C-S-H gel, so that the efficiency is obviously improved compared with that of a single crystal nucleus due to the reason.

Referring to fig. 5, fig. 5 is an infrared spectrum of component B, which shows that the monomer residues are retained in the polymer and thus can serve the intended purpose. The excess sodium silicate provides additional alkalinity and provides hydrolysis conditions for the methyl tribromomethacrylate residue when component A, B is mixed, allowing it to partially hydrolyze to release carboxyl groups. At this time, the dispersing ability of the component B is enhanced, and the superfine component A is fully dispersed to fully release the specific surface area and exert the effect. The tribromomethyl has a larger radius, and is not easy to enter into gaps of the polymer molecules when the polymer molecules are adsorbed on the surfaces of the component A particles or the surfaces of the cement particles through electrostatic action, so that the polymer molecules are adsorbed and fail. The detailed analysis of the infrared active groups is shown in the following table, and the high molecular infrared spectrum is more complex and does not exclude other explanation possibilities.

Watch II

In the alkaline environment provided by saturated calcium hydroxide of concrete, tribromomethyl can react with hydroxyl ions slowly in nucleophilic substitution, and a small amount of bromine substituent can be changed into hydroxyl substituent. In the process, the hydrophilic surface activity of the gel is gradually enhanced, and the increase of hydroxyl groups can strengthen the hydrogen bonding action of the gel and C-S-H gel generated in the hydration process, so that the gel growth has directionality, and particles adsorbed by the component B molecules are directionally bonded.

The low-carbon concrete additive, the preparation method thereof and the low-carbon concrete can effectively reduce the consumption of cement in the concrete, the reduction range can be up to 50%, and each performance of the concrete is the same as or better than that of the conventional concrete. The reduction of the amount of cement in the concrete can reduce the cost of materials required for manufacturing the concrete by 10 to 15 percent. The low-carbon concrete provided by the application has excellent durability, the carbonization resistance and sulfate erosion resistance of the low-carbon concrete are improved in multiple than those of conventional concrete, the service life of the concrete is expected to be 1.5-2 times that of conventional concrete, and the low-carbon concrete has a great application value in projects with high durability requirements. And the cement consumption is reduced, and the consumption of other light-colored materials such as mineral powder is improved, so that the overall color of the concrete is lighter and more attractive.

Furthermore, the descriptions of the terms "some embodiments," "other embodiments," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In the present application, the schematic representations of the above terms are not necessarily for the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples of the present application and features of various embodiments or examples may be combined and combined by those skilled in the art without contradiction.

The above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and they should be included in the protection scope of the present application.

Claims

1. The preparation method of the low-carbon concrete additive is characterized by comprising the following steps of:

uniformly mixing a component A and a component B, wherein the preparation method of the component A comprises the following steps: weighing 24-36 parts of aluminate cement, 8-12 parts of limestone powder, 8-12 parts of mineral powder, 0.8-1.2 parts of liquid sodium silicate and 20-30 parts of water according to parts by weight, adding the materials into a stirring kettle, fully stirring, standing for 36-48h at 80+/-5 ℃ under the environment with the humidity of 95-100%, drying at 70-90 ℃, and grinding to obtain the component A;

2. The method of claim 1, wherein the weight ratio of component a to component B is 1:2-2:1.

3. The method of claim 1, wherein the liquid sodium silicate has a modulus of 1.2 to 1.5.

4. A method of preparation according to claim 3, wherein the liquid sodium silicate has a solids content of 40-60%.

5. The process according to claim 1, wherein the component A has a Bosch specific surface area of more than 600m ² /kg。

6. The method according to claim 1, wherein the molecular weight of the p-bromophenyl allyl alcohol polyoxyethylene ether is 2000 to 3000.

7. The preparation method according to claim 1, wherein the mass fraction of the hanging white block solution is 5%.

8. The method of claim 1, wherein the method of preparing component B further comprises: uniformly dripping 10 parts by weight of the white suspending block solution into the mixed solution within 90-120 min.

9. A low carbon concrete additive, characterized in that it is prepared by the method of preparing a low carbon concrete additive according to any one of claims 1 to 8.

10. A low carbon concrete comprising: water, cement, fly ash, mineral powder, sand, crushed stone, an admixture and the low carbon concrete additive of claim 9 for reducing the amount of cement in the low carbon concrete.