CN112390581B

CN112390581B - Environment-friendly concrete and preparation method thereof

Info

Publication number: CN112390581B
Application number: CN202011339853.XA
Authority: CN
Inventors: 卫晓勇; 王鑫; 刘杰; 高元辉
Original assignee: Beijing Urban Construction Jiuqiushi Concrete Co ltd
Current assignee: Beijing Urban Construction Jiuqiushi Concrete Co ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2022-06-28
Anticipated expiration: 2040-11-25
Also published as: CN112390581A

Abstract

The application relates to the field of concrete, and particularly discloses environment-friendly concrete and a preparation method thereof, wherein the environment-friendly concrete comprises, by weight, 280 portions of cement-containing materials 320, 500 portions of sand-containing materials 800, 900 portions of stones 700-containing materials, 400 portions of concrete waste particles 200-containing materials, 100 portions of steel slag powder 160, 200 portions of colloidal particles 120-containing materials, 5-12 portions of a water reducing agent, 12-25 portions of an early strength agent, and 300 portions of water 200-containing materials, and the steel slag powder is coated on the surfaces of the colloidal particles; the preparation method comprises the following steps: mixing dry materials: proportionally mixing cement, sand, stones, concrete waste particles, steel slag powder and colloidal particles, uniformly stirring, adding a water reducing agent and water, and stirring for 30-40 min; during the stirring period, the early strength agent is added, and the stirring is completed. The application of the environment-friendly concrete has the advantages that waste garbage is recycled, and the environment is protected.

Description

Environment-friendly concrete and preparation method thereof

Technical Field

The application relates to the technical field of concrete materials, in particular to environment-friendly concrete and a preparation method thereof.

Background

The concrete is a building material with the largest use amount at present, and is mainly prepared by mixing a cementing material, coarse and fine aggregates and water. With the increasing of the infrastructure speed of China, the demand of concrete is increasing year by year, and the demand of coarse and fine aggregates serving as main components in the concrete is also increasing year by year.

Coarse and fine aggregates in the concrete are generally extracted from natural gravels in the riverbed, and the ecological environment of the riverbed is easily damaged by excessive extraction of the gravels. Meanwhile, the garbage such as building garbage, blast furnace slag and the like generated in production and life is not easy to degrade, and the garbage is randomly stacked and buried to influence the environment.

Therefore, the concrete which uses the garbage in production and living as the concrete raw material supplement is developed, and the concrete has wide market value and application prospect.

Disclosure of Invention

The application provides an environment-friendly concrete and a preparation method thereof. Has the effects of recycling the produced domestic garbage and protecting the environment.

In a first aspect, the present application provides an environment-friendly concrete, which adopts the following technical scheme:

an environment-friendly concrete comprises, by weight, 320 parts of cement 280 plus materials, 800 parts of sand 500 plus materials, 900 parts of stone 700 plus materials, 400 parts of concrete waste particles 200 plus materials, 160 parts of steel slag powder 100 plus materials, 200 parts of colloidal particles 120 plus materials, 5-12 parts of a water reducing agent, 12-25 parts of an early strength agent, 300 parts of water 200 plus materials, and the steel slag powder is coated on the surfaces of the colloidal particles.

By adopting the technical scheme, the concrete waste particles come from construction waste generated in work such as dismantling an original building in life, the steel slag powder comes from steel slag generated in steel making in a steel mill, and the colloidal particles come from scrapped tires. The raw materials are not easy to decompose when used for producing the household garbage, the treatment difficulty is high, and the environment is negatively influenced by random stacking and landfill.

The crushed concrete waste particles can be used as the supplement of sand and stones to be added into the concrete, and the concrete waste is used as the supplement of dry aggregate in the concrete slurry, so that the demand of fresh concrete on the sand and the stones is reduced, and the excessive exploitation of gravels in a river bed is reduced, thereby protecting the ecological environment; and because the components of the concrete waste and the mixed concrete are similar, the combination of the concrete waste and the sandstone aggregate in the mixed concrete after the mixed concrete is mixed with the concrete waste is good;

the steel slag is a byproduct obtained by cooling a melt which is generated in the steel-making process and takes dicalcium silicate and tricalcium silicate as main components. The steel slag powder is powder obtained by crushing and grinding steel slag, and the steel slag powder is added, so that the steel slag contains active mineral substances such as dicalcium silicate, tricalcium silicate, iron aluminate and the like similar to cement, has hydraulic gelation property, can be used as a supplement of the cement, and plays a certain role of hydraulic hardening in concrete mortar. The addition of the steel slag powder makes waste utilization on the steel slag powder, and reduces the use amount of cement, thereby generating higher economic value.

The rubber particles are formed by crushing waste tires, and can play a role of aggregate after the concrete slurry is added, on one hand, the tires are used for a long time to be scrapped, and after the scrapped tires are cut and crushed, cracks are generated inside the rubber particles, and gaps are provided for the inside of the concrete after the rubber particles are added into the concrete slurry; on the other hand, the colloidal particles have certain elasticity, and after the concrete slurry is added, the concrete has certain elasticity inside, so that the supersaturated stress inside the concrete can be absorbed, and the frost resistance of the concrete can be improved.

The steel slag contains the dicalcium silicate and tricalcium silicate mentioned above, free calcium oxide is also retained in the steel slag, the free calcium oxide is compact in structure after high-temperature sintering, the hydration speed is slow, and the volume expands when calcium hydroxide is generated by hydration, so that the hardened cement body generates expansion stress, the tensile strength of the cement is reduced, the stability of the cement is poor, and the colloidal particles are added, and because the colloidal particles have elasticity, the colloidal particles are extruded by the steel slag and compressed, so that the pressure generated by the volume expansion of the steel slag is absorbed, the condition of concrete burst is reduced, and the durability of the concrete is improved.

Preferably, the average grain size of the steel slag powder is 40-70 μm.

Through adopting above-mentioned technical scheme, on the one hand along with the reduction of slag powder particle diameter, slag powder is more even in the internal dispersion of concrete slurry, thereby when free calcium oxide in the slag powder takes place hydration inflation, the more even dispersion of stress that the hydration inflation produced is in each department of concrete, thereby make the inside stress dispersion of concrete more even, thereby the condition that the concrete bursts has been reduced, on the other hand, slag powder particle diameter is injectd, make the more stable surface of attaching to at the micelle of slag powder.

Preferably, the average particle size of the colloidal particles is 1-2 cm.

Through adopting above-mentioned technical scheme, the injecing of the granule of micelle for the micelle has kept the graininess of micelle when mixing in concrete slurry easily, thereby has improved the elasticity of micelle.

Preferably, the concrete waste particles comprise coarse waste and fine waste;

the weight ratio of the coarse waste to the fine waste was 0.7: 1.

Preferably, the concrete particles are prepared by the following method:

selecting raw materials: selecting the obtained construction waste, selecting metal waste and wood waste,

crushing raw materials: crushing the raw material to a particle size of less than 0.5mm to obtain a raw material prefabricated product;

Purification of the raw material preform: carbon powder accounting for 5 percent of the weight of the raw material prefabricated product is mixed in the raw material prefabricated product, and the raw material prefabricated product is subjected to aerobic high-temperature ignition.

And (3) screening the coarse waste and the fine waste, namely passing the crushed raw materials through a 2.35mm square-hole sieve, wherein the screened materials are the fine waste, and the non-passed materials are the coarse waste.

By adopting the technical scheme, after the construction waste is selected, non-concrete impurities such as scrap iron, wood, waste plastics and the like in the construction waste are removed, the construction waste is crushed, so that the crushed particles can pass through a 0.5mm square hole sieve to obtain a raw material prefabricated product, and the particle size in the raw material prefabricated product is less than 0.5 mm. And then, the raw material prefabricated product is sieved by a 2.35mm square-hole sieve, the sieved substances are fine waste materials, the unscreened substances are coarse waste materials, the fine waste materials and the coarse waste materials are respectively weighed and are respectively added according to the proportion, and after the coarse powder materials and the unscreened materials are added according to the proportion, the matching degree with stones and sand is higher, so that the workability and the water retention property of the concrete are improved.

Preferably, the raw material is soaked in water for 24h before being crushed.

Through adopting above-mentioned technical scheme, the raw materials is by the water logging back, space and crack between the raw materials are full of by water, when broken, the breaker vibrations and mutually support with the inside moisture of filling of raw materials to make original space and crack grow of raw materials, and then break into the tiny particle with the raw materials, it is broken when not soaking water to have reduced the raw materials, and introduce more cracks, and then influence the thin waste material and the thick waste material intensity condition after smashing, further improved the intensity behind the environmental protection concrete shaping.

Preferably, the early strength agent comprises nitrite, formic acid, triethanolamine and fly ash, and the weight ratio is 1: 1:0.1-0.2:10.

The preferred nitrite is sodium nitrite.

By adopting the technical scheme, the triethanolamine is a surfactant, is doped into cement concrete, plays a role of a catalyst in the cement hydration process, and can accelerate the hydration of C3A and the formation of ettringite. The sodium nitrite can promote the cement water bloom, thereby further accelerating the hardening of the cement.

Nitrous acid has still played the effect of rust inhibitor and antifreeze simultaneously, and nitrite can reduce the freezing point of concrete mortar to play frost-resistant effect, when adding the reinforcing bar in the concrete, sodium nitrite can also promote the reinforcing bar surface to produce the compact oxide film, thereby has protected the reinforcing bar, has reduced the condition of reinforcing bar corrosion.

Formic acid contains rich carboxylate ions, and the carboxylate ions reduce the surface tension of a concrete liquid phase, so that the fluidity of concrete slurry is improved, the water requirement of the concrete slurry is reduced, and the setting speed of concrete is accelerated. Acid ions are introduced while the formic acid is added, so that a part of free calcium oxide can be consumed, calcium formate is generated, and the early strength of the concrete is further promoted by the calcium formate, so that the early hardness and the compressive strength of the concrete are further improved.

Through the mixing ratio of the three raw materials, the nitrite neutralizes the corrosion effect of triethanolamine and formic acid on the steel bars in the concrete, the formic acid provides an acidic environment to improve the activity of the nitrite, and the three raw materials are mutually matched, so that the early strength of the concrete is effectively improved, and the corrosion degree of the steel bars in the concrete is reduced.

In a second aspect, the present application provides a method for processing an encircling concrete body, which adopts the following technical scheme:

the preparation method of the environment-friendly concrete comprises the following steps:

mixing dry materials: mixing and uniformly stirring 320 parts by weight of cement 280 plus materials, 800 parts by weight of sand 500 plus materials, 900 parts by weight of stones 700 plus materials, 400 parts by weight of concrete waste particles 200 plus materials, 300 parts by weight of steel slag powder 200 plus materials and 20-120 parts by weight of colloidal particles,

dissolving an additive: dissolving 5-12 parts of water reducing agent in 50 parts of water by weight, and uniformly stirring to obtain a water material;

mixing dry materials and water materials. Adding the water material into the dry material, then supplementing the rest water according to a set proportion, and stirring at a stirring speed of 20r/min for 30-40 min;

and adding the early strength agent when the stirring time reaches 20min, and continuing stirring.

By adopting the technical scheme, the dry materials are mixed with the additive solution after being stirred, then are stirred with the residual water amount, and the early strength agent is added after being stirred to midway, so that the operation is to enable the early strength agent to be more uniformly mixed in the concrete and properly delay the effective time of the early strength agent, thereby facilitating the transportation and grouting of the fresh concrete.

Preferably, the steel slag powder and the colloidal particles are pretreated before the dry materials are mixed, and the specific steps comprise that the colloidal particles are soaked in a solvent for 30-40min, then the colloidal particles are added into the steel slag powder, and the steel slag powder is adhered to the surfaces of the colloidal particles through stirring.

Preferably, the solvent can be one or more of n-amyl alcohol, isoamyl alcohol, ethyl acetate and glycerol.

Through adopting above-mentioned technical scheme, the micelle swells under the effect of solvent, thereby the surface softens, the molecular gap grow on micelle surface, thereby can carry out good adhesion to the slag powder, through combining the back with the slag powder with the micelle, when the slag powder takes place free calcium oxide and turns into calcium hydroxide and takes place the volume inflation in the later stage of concrete setting, the micelle can carry out timely absorption to the stress that produces when the slag powder volume inflation, thereby reduced because the condition that local area takes place to burst in the muddy earth.

Since the organic solvent can affect the mechanical properties of the colloidal particles when the colloidal particles are swelled, the time for soaking the colloidal particles in the solvent needs to be controlled when the colloidal particles are swelled, so that the swelling depth of the colloidal particles is controlled, the surface of the colloidal particles is swelled, and the mechanical properties of the colloidal particles are maintained inside the colloidal particles. Thereby improving the stability of the colloidal particles added into the concrete.

Preferably, the preparation of the early strength agent: adding nitrite and formic acid into 3wt% acetic acid solution in proportion, uniformly stirring, adding fly ash, uniformly stirring, wherein the ratio of sodium nitrite to acetic acid solution is 1: 3.

by adopting the technical scheme, the sodium nitrite and the formic acid are put into the acetic acid solution to be dissolved, and then the fly ash is used for absorbing the generated solvent, so that the effective components of the early strength agent are adsorbed in the fly ash, the fly ash plays a slow release role in the early strength agent, and the effective time of the early strength agent is delayed.

In summary, the present application has the following beneficial effects:

1. the environment-friendly concrete disclosed by the application is used for reprocessing waste garbage in production and living, such as construction waste, waste tires and steel slag, and is used in production of concrete, the prepared concrete has better performance, the waste is effectively treated, and the effects of energy conservation and environment protection are achieved.

2. By using the early strength agent, the drying speed and the solidification strength of the concrete at the early stage are improved, and the reinforcement in the concrete can be protected against rust, so that the stability of the concrete at the early stage and in long-term use is improved.

3. The method improves the comprehensive performance of the concrete by pretreating various raw materials, reasonably recycles the produced household garbage and reduces the influence on the environment.

Detailed Description

The application discloses a preparation method of environment-friendly concrete, and raw materials used by the preparation method can be purchased and obtained from markets.

The present application will be described in further detail with reference to examples.

Examples

Example 1

The environment-friendly concrete comprises the following components in parts by weight:

280 parts of cement, 500 parts of sand, 700 parts of pebbles, 82 parts of fine waste, 118 parts of coarse waste, 100 parts of steel slag powder, 120 parts of colloidal particles, 5 parts of a water reducing agent, 12 parts of an early strength agent (sodium nitrite, formic acid, triethanolamine and fly ash) and 200 parts of water.

A preparation method of environment-friendly concrete,

preparation of concrete particles:

selecting raw materials: selecting the obtained construction waste, and selecting metal waste and wood waste;

purification of the raw material preform: carbon powder accounting for 5 percent of the weight of the raw material prefabricated product is doped into the raw material prefabricated product, and aerobic high-temperature ignition is carried out for 30 min;

Screening of coarse waste and fine waste: and (3) passing the crushed raw materials through a 2.35mm square-hole sieve, wherein the sieved substances are fine waste materials, and the non-passed substances are coarse waste materials.

Preparing colloidal particles:

crushing waste tires to prepare colloidal particles with the average particle size of 1 cm;

preparing steel slag powder:

the steel slag was pulverized into powder having an average particle size of 40 μm.

Pretreating colloidal particles and steel slag powder: and soaking the colloidal particles in the solvent for 30-40min, then taking out the colloidal particles, adding the colloidal particles into the steel slag powder, and stirring to ensure that the steel slag powder is adhered to the surfaces of the colloidal particles.

Preparation of the early strength agent: adding sodium nitrite and formic acid into a 3wt% acetic acid solution in proportion, uniformly stirring, adding fly ash, uniformly stirring, wherein the weight ratio of the sodium nitrite to the formic acid to the triethanolamine to the fly ash to the acetic acid solution is 1: 1:0.1:10:3. (in this example, sodium nitrite is selected as nitrite)

Mixing dry materials: mixing 280 parts by weight of cement, 500 parts by weight of sand, 700 parts by weight of stones, 82 parts by weight of fine waste, 118 parts by weight of coarse waste, 200 parts by weight of steel slag powder and 20 parts by weight of colloidal particles, uniformly stirring,

dissolving the additive: dissolving 5 parts of water reducing agent in 50 parts of water by weight, and uniformly stirring to obtain a water material;

mixing dry materials and water materials. Adding the water material into the dry material, then supplementing the rest water according to a set proportion, and stirring at a stirring speed of 20r/min for 30 min;

When the stirring time reaches 20min, 12 parts of the early strength agent is added, and the stirring is continued.

Example 2

The environment-friendly concrete comprises, by weight, 320 parts of cement, 800 parts of sand, 900 parts of stones, 164 parts of fine waste, 236 parts of coarse waste, 160 parts of steel slag powder, 200 parts of colloidal particles, 12 parts of a water reducing agent, 25 parts of an early strength agent (sodium nitrite, formic acid, triethanolamine and fly ash) and 300 parts of water.

Preparation of concrete particles:

selecting raw materials: selecting the obtained construction waste, and removing metal waste and wood waste in the construction waste;

Preparing colloidal particles:

crushing waste tires to prepare colloidal particles with the average particle size of 2 cm;

preparing steel slag powder:

the steel slag was pulverized into powder having an average particle size of 70 μm.

Preparation of the early strength agent: adding sodium nitrite and formic acid into 3wt% acetic acid solution in proportion, uniformly stirring, adding fly ash, and uniformly stirring, wherein the weight ratio of the sodium nitrite to the formic acid to the triethanolamine to the fly ash to the acetic acid solution is 1:1:0.2:10:3 (in the embodiment, sodium nitrite is selected as nitrite).

Mixing dry materials: mixing and uniformly stirring 320 parts of cement, 800 parts of sand, 900 parts of stones, 164 parts of fine waste, 236 parts of coarse waste, 300 parts of steel slag powder and 120 parts of colloidal particles,

dissolving the additive: dissolving 12 parts of water reducing agent in 50 parts of water by weight, and uniformly stirring to obtain a water material;

mixing dry materials and water materials. Adding the water material into the dry material, then supplementing the rest water according to a set proportion, and stirring at a stirring speed of 20r/min for 40 min;

and when the stirring time reaches 20min, adding 25 parts of the early strength agent, and continuing stirring.

Example 3

The difference from example 1 is that the average grain size of the steel slag powder was 70 μm.

Example 4

The difference of example 1 is that the weight ratio of sodium nitrite, formic acid, triethanolamine, fly ash and acetic acid solution in the early strength agent is 1:1:0.2:10:3 (in this example, sodium nitrite is used as nitrite).

Comparative example

Comparative example 1

The difference from example 1 is that no steel slag powder and no colloidal particles were added.

Comparative example 2

The difference from example 1 is that no colloidal particles were added.

Comparative example 3

The difference from example 1 is that the screening of the coarse and fine wastes is not performed during the processing of the concrete waste particles.

Comparative example 3

The difference from example 1 is that the purification of the raw material preform is not performed during the processing of the concrete waste particles.

Comparative example 4

The difference from example 1 is that the concrete waste particles were not soaked for 24h before breaking.

Comparative example 5

The difference from example 1 is that no pretreatment of the steel slag powder and the billet was performed.

Comparative example 6

The difference from example 1 is that no early strength agent was added.

Comparative example 7

The difference from example 1 is that formic acid was not added to the early strength agent.

Comparative example 8

The difference from example 1 is that formic acid and sodium nitrite are not added to the early strength agent.

Comparative example 9

The difference from example 1 is that no fly ash is added to the early strength agent.

Performance test

By measuring the concrete strengths of examples 1 to 4, comparative examples 1 to 7, at 7 days, 28 days, and 50 days, and observing the cracking of the surface of the concrete test piece after 50 days, the following data were obtained;

TABLE 1 Performance test of examples 1-4 and comparative examples 1-7

	Compressive strength (3 d)	Compressive strength (7 d)	Compressive strength (28 d)	Compressive strength (50 d)	Cracking event (50 d)
						Example 1	44.3	48.2	52.7	55.3	Is not cracked
Example 2	46.1	49.7	51.9	54.6	Is not cracked
						Example 3	43.9	46.7	50.4	53.7	Is not cracked
Example 4	45.3	48.1	53.1	55.4	Is not cracked
						Comparative example 1	40.1	44.3	47.9	51.1	Is not cracked
Comparative example 2	45.6	48.3	51.4	53.1	Cracking of
						Comparative example 3	41.6	46.6	50.1	52.7	Cracking of
Comparative example 4	42.2	47.7	49.3	51.6	Is not cracked
						Comparative example 5	45.1	48.9	51.4	54.4	Cracking of
Comparative example 6	33.7	40.3	44.1	46.2	Cracking of
						Comparative example 7	41.2	45.3	48.2	51.4	Is not cracked
Comparative example 8	38.2	42.3	45.7	49.2	Is not cracked
						Comparative example 9	46.2	49.3	52.9	55.1	Cracking of

It can be seen from the combination of examples 1,2 and 3 and comparative examples 1 and 2 and the combination of table 1 that the addition of the steel slag powder helps to improve the compressive strength of the concrete sample, and the steel slag powder improves the early strength of the concrete more as the particle diameter of the steel slag powder is reduced, which may be caused by the hydration of some gelled substances in the steel slag powder in the concrete, thereby improving the internal structural strength of the concrete, while the reduction of the modulus of the steel slag powder increases the surface area of the steel slag powder, and makes the distribution of the steel slag powder in the concrete more uniform, thereby improving the compressive strength of the concrete.

And the setting of micelle has increased the inside elasticity of muddy earth to can adapt to slag powder volume expansion, thereby reduced the condition of concrete sample surface fracture.

By combining the examples 1 and 4 and the comparative examples 6, 7 and 8, the early strength agent can effectively improve the early compressive strength of concrete, and the effective time of the early strength agent is advanced and the early strength is improved rapidly along with the increase of the dosage of triethanolamine. The addition of sodium nitrite and formic acid introduces other early strength agent types, and the formic acid helps to improve the activity of the sodium nitrite, thereby improving the early solidification speed of the concrete.

It can be seen from the combination of example 1 and comparative example 9 that the fly ash plays a role in adsorbing and slowly releasing in the early strength agent, and the nitrite, formic acid and triethanolamine are adsorbed in pores of the fly ash and slowly released in the concrete, so that the effective time of the early strength agent is controlled, and the early solidification efficiency of the concrete is controlled. The concrete of comparative example 9 was cracked due to the excessively fast setting speed, so that the uncured portion inside the concrete did not have time to flow and creep to uniform the stress inside the concrete, thereby causing uneven distribution of stress inside the concrete, which in turn caused cracking and affected the strength of the concrete.

By combining the example 1 and the comparative examples 3 and 4, it can be seen that the quality of the concrete waste is improved and the strength of the concrete after the concrete fertilizer particles are used as aggregate is improved by the pretreatment of the concrete waste particles, including the burning purification and the soaking treatment of the prefabricated product.

The specific embodiments are only for explaining the present application and are not limiting to the present application, and those skilled in the art can make modifications to the embodiments without inventive contribution as required after reading the present specification, but all the embodiments are protected by patent law within the scope of the claims of the present application.

Claims

1. The environment-friendly concrete is characterized by comprising, by weight, 320 parts of 280-sand-doped cement, 800 parts of 500-sand-doped sand, 900 parts of stone 700-doped sand, 400 parts of concrete waste particles, 160 parts of steel slag powder, 200 parts of colloidal particles, 5-12 parts of a water reducing agent, 12-25 parts of an early strength agent and 300 parts of water 200-doped sand-doped steel slag powder, wherein the steel slag powder is coated on the surfaces of the colloidal particles;

the average grain size of the steel slag powder is 40-70 mu m;

the average grain diameter of the colloidal particles is 1-2 cm;

the method for coating the steel slag powder on the surface of the colloidal particles comprises the following steps: soaking the colloidal particles in a solvent for 30-40min, then adding the colloidal particles into the steel slag powder, and stirring to make the steel slag powder attached to the surfaces of the colloidal particles;

the concrete waste particles comprise coarse waste and fine waste;

the weight ratio of the coarse waste to the fine waste is 0.7: 1;

the concrete particles are prepared by the following method:

Crushing raw materials: crushing the raw material until the particle size is less than 0.5mm to obtain a raw material prefabricated product;

purification of the raw material preform: carbon powder accounting for 5 percent of the weight of the raw material prefabricated product is doped into the raw material prefabricated product, and aerobic high-temperature firing is carried out;

screening coarse waste and fine waste, namely passing the crushed raw materials through a 2.35mm square-hole sieve, wherein the screened substances are fine waste, and the non-passed substances are coarse waste;

the early strength agent comprises sodium nitrite, formic acid, triethanolamine and fly ash, and the weight ratio is 1: 1:0.1-0.2:10.

2. The environment-friendly concrete according to claim 1, wherein: the raw materials need to be soaked in water for 24h before being crushed.

3. A method for preparing environment-friendly concrete according to claim 1 or 2, wherein the method comprises the following steps: the method comprises the following steps:

mixing dry materials: according to the weight portion, 320 portions of cement 280 plus materials, 800 portions of sand 500 plus materials, 900 portions of stones 700 plus materials, 400 portions of concrete waste particles 200 plus materials, 300 portions of steel slag powder 200 plus materials and 20-120 portions of colloidal particles are mixed and stirred evenly,

mixing dry materials and water materials: adding the water material into the dry material, then supplementing the residual water according to a set proportion, and stirring at the stirring speed of 20r/min for 30-40 min;

Adding the early strength agent when the stirring time reaches 20min, and continuing stirring;

preparation of the early strength agent: adding sodium nitrite and formic acid into a 3wt% acetic acid solution according to a certain proportion, uniformly stirring, then adding triethanolamine, uniformly stirring again, adding fly ash, and uniformly stirring, wherein the weight ratio of sodium nitrite to acetic acid solution is 1: 3.