CN113248203B

CN113248203B - Anti-permeability high-strength concrete and preparation method thereof

Info

Publication number: CN113248203B
Application number: CN202110565903.4A
Authority: CN
Inventors: 兰丁就; 黎锦照; 何以津
Original assignee: Foshan Nanhai Xiqiao Hengjian Concrete Co ltd
Current assignee: Foshan Nanhai Xiqiao Hengjian Concrete Co ltd
Priority date: 2021-05-24
Filing date: 2021-05-24
Publication date: 2021-12-21
Anticipated expiration: 2041-05-24
Also published as: CN113248203A

Abstract

The application relates to the field of artificial stones, and particularly discloses anti-permeability high-strength concrete and a preparation method thereof. The impervious high-strength concrete comprises cement, fly ash, fine aggregate, recycled coarse aggregate and water in a weight ratio of 1: (0.15-0.17): (1.42-1.47): (2.39-2.43): (0.30-0.35), wherein the mixing amount of the water reducing agent is 2-3% of the cement amount; the preparation method of the anti-permeability high-strength concrete comprises the following steps: and uniformly mixing the cement, the fly ash, the fine aggregate, the recycled coarse aggregate, the water reducing agent and water according to the proportion to obtain the anti-permeability high-strength concrete. The anti-permeability high-strength concrete has better anti-permeability performance and compressive performance, and can meet the requirement of pumping.

Description

Anti-permeability high-strength concrete and preparation method thereof

Technical Field

The application relates to the field of artificial stone, in particular to impervious high-strength concrete and a preparation method thereof.

Background

The concrete is artificial stone obtained by uniformly mixing, molding and hardening cement, water, sand, stones, chemical additives, admixtures and the like. With the continuous expansion of urban areas, a large number of buildings need to be built, and concrete as a building material with the most extensive modern application inevitably needs to be prepared and used in a large amount.

In order to reduce the waste of resources, at present, some people research and use waste concrete to replace stones to prepare concrete. However, researches have found that when waste concrete is used to replace stones to prepare concrete, the obtained concrete has poor impermeability and compressive property, and cannot meet the construction requirements. The analysis may cause more pores in the waste concrete, which results in poor impermeability and compressive strength of the newly prepared concrete.

For this reason, the related art has also studied how to reduce the porosity in the waste concrete, for example, by adding a water-absorbent expansive material to the waste concrete or adding an expansive agent to the fresh concrete, thereby reducing the porosity in the fresh concrete. However, although these operations can reduce the porosity of the concrete to some extent, the improvement in the impermeability or compressive strength of the concrete is still not particularly significant, and the workability of the concrete is liable to deteriorate, failing to meet the pumping requirements.

Disclosure of Invention

In order to solve the problem that the performance of newly-made concrete is poor when the newly-made concrete is prepared by adopting waste concrete, the application provides the anti-permeability high-strength concrete and the preparation method thereof.

In a first aspect, the present application provides an impervious high strength concrete, using the following technical scheme:

an impervious high-strength concrete comprises raw materials of cement, fly ash, sand, stone, water and a water reducing agent; the weight ratio of the cement, the fly ash, the fine aggregate, the regenerated coarse aggregate and the water is 1: (0.15-0.17): (1.42-1.47): (2.39-2.43): (0.30-0.35), wherein the mixing amount of the water reducing agent is 2-3% of the cement amount; the recycled coarse aggregate comprises a coarse aggregate body made of waste concrete, water-absorbing expansion filling particles filled in pores of the coarse aggregate body, a reinforcing layer coated on the outer peripheral side of the coarse aggregate body and a hydrophobic layer coated on the outer side of the reinforcing layer.

By adopting the technical scheme, the inventor firstly crushes the waste concrete to prepare the coarse aggregate body, then fills the water-absorbing expansion filling particles into the pores of the coarse aggregate body, then coats the reinforcing layer on the peripheral side of the coarse aggregate body, coats the hydrophobic layer on the peripheral side of the reinforcing layer to prepare the regenerated coarse aggregate, and can obtain the concrete which has better impermeability and compression resistance and is suitable for pumping after the obtained regenerated coarse aggregate is uniformly mixed with other concrete raw materials according to a certain proportion; in addition, this application recycles waste concrete, is favorable to reducing the production of waste material, has energy-concerving and environment-protective effect.

Preferably, the particle size range of the water absorption swelling filling particles is 10-20 mu m.

By adopting the technical scheme, when the particle size range of the water-swelling filling particles is 10-20 mu m, the impermeability of the concrete is further improved. The inventor guesses that the reason is that the water absorption expansion filling particles in the particle size range have good dispersibility, are not easy to agglomerate, are easy to enter pores of the waste concrete, and are beneficial to improving the compactness of the recycled coarse aggregate, so that the compactness of the concrete is improved, and the impermeability of the concrete is improved.

Preferably, the water-absorbing swelling filling particles are made of super absorbent resin, and the super absorbent resin is one or a combination of more of polyacrylamide, sodium polyacrylate and carboxymethyl cellulose.

By adopting the technical scheme, the polyacrylamide, the sodium polyacrylate and the carboxymethyl cellulose are high-water-absorption resins, and the high-water-absorption resins are expanded after absorbing water to fill the pores in the coarse aggregate body, so that the compactness of the regenerated coarse aggregate body is improved, the compactness of concrete is improved, and the impermeability and the compressive property of the concrete are improved.

Preferably, the preparation method of the recycled coarse aggregate comprises the following steps:

step S1, filling the coarse aggregate body: adding 400-500 sand into 2000 parts by weight of coarse aggregate body

The water-absorbing expanded filler particles in parts by weight are fully mixed and vibrated, so that the water-absorbing expanded filler particles enter pores of the coarse aggregate body to obtain a compact coarse aggregate body;

step S2, wrapping the reinforcing layer: adding 440 parts by weight of water and 540 parts by weight of water into the compact coarse aggregate body

Slurry, namely coating a layer of cement slurry on the outer peripheral side of the compact coarse aggregate body to obtain a reinforced coarse aggregate body;

step S3, coating a hydrophobic layer: and adding 800-1000 parts by weight of hydrophobic coating into the reinforced coarse aggregate body to coat a layer of hydrophobic coating on the outer peripheral side of the reinforced coarse aggregate body, thus obtaining the recycled coarse aggregate.

By adopting the technical scheme, the pores of the coarse aggregate body are filled by adopting the water-absorbing expansion filling particles, so that the compactness of the coarse aggregate body is improved; a layer of cement paste is coated on the outer peripheral side of the compact coarse aggregate body, and the compression resistance of the compact coarse aggregate body is improved after the cement paste is cured; in addition, the periphery of the reinforced coarse aggregate body is coated with the hydrophobic layer, and the hydrophobic layer can reduce the problem that subsequent water enters the coarse aggregate body to cause poor workability of concrete.

Preferably, the step S1 is preceded by a step S0 of cleaning the coarse aggregate body: and (4) adding the coarse aggregate body into water, cleaning the coarse aggregate body under the auxiliary action of ultrasonic waves, and filtering and drying the coarse aggregate body after the coarse aggregate body is cleaned up to be used as a spare material in the step S1.

By adopting the technical scheme, after the step of cleaning the coarse aggregate body is added, the compressive strength of the concrete is further improved. The reason may be that the washing step may remove some loose sludge in the coarse aggregate body and fill it with water-swellable particles, thereby improving the compressive strength of the concrete.

Preferably, the preparation method of the cement paste is as follows:

firstly, 50-70 parts by weight of silane coupling agent is added into 1000 parts by weight of water and stirred uniformly to obtain

Premixing liquid; then adding 200-400 parts by weight of cement into the premixed liquid, and uniformly stirring to obtain the cement slurry.

By adopting the technical scheme, the silane coupling agent is added into the cement paste, so that the slump of the concrete is further improved, and the anti-permeability performance and the compressive strength of the concrete are not changed greatly. The reason may be that the addition of the silane coupling agent improves the bonding force between the hydrophobic layer and the reinforcing layer, so that the hydrophobic layer is not easy to fall off from the reinforcing layer, thereby further improving the workability of the concrete.

Preferably, the cement is P.O 42.5.5R cement.

By adopting the technical scheme, the P.O 42.5.5R cement has the characteristics of high early strength and low hydration heat, and can reduce the temperature rise caused by cement hydration.

Preferably, the fly ash is II-grade fly ash.

By adopting the technical scheme, the grade II fly ash has moderate fineness, better strength and lower price compared with the grade I fly ash, and has the characteristic of being more economic.

Preferably, the particle size range of the fine aggregate is 0.3-0.5mm, and the continuous gradation of the recycled coarse aggregate is 5-25 mm.

By adopting the technical scheme, the fine aggregate can better enter the pores among the recycled coarse aggregates, and the compactness of the concrete is favorably improved, so that the impermeability and the compressive property of the concrete are improved.

In a second aspect, the present application provides a method for preparing an impervious high-strength concrete, which adopts the following technical scheme:

a preparation method of anti-permeability high-strength concrete comprises the following steps: and uniformly mixing the cement, the fly ash, the fine aggregate, the recycled coarse aggregate, the water reducing agent and water according to the proportion to obtain the anti-permeability high-strength concrete.

By adopting the technical scheme, the method for preparing the concrete has the advantages of simple process and convenience in operation.

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

1. the method comprises the steps of firstly crushing waste concrete to prepare a coarse aggregate body, then filling water-absorbing expansion filling particles into pores of the coarse aggregate body, then coating a reinforcing layer on the outer peripheral side of the coarse aggregate body, and then coating a hydrophobic layer on the outer peripheral side of the reinforcing layer to prepare regenerated coarse aggregate; in addition, this application recycles waste concrete, is favorable to reducing the production of waste material, has energy-concerving and environment-protective effect.

2. The water absorption swelling filling particles with the particle size range of 10-20 mu m are preferably adopted in the application, and the anti-permeability performance of the concrete is further improved.

3. The silane coupling agent is added into the cement paste, so that the slump of the concrete is further improved, and the anti-permeability performance and the compressive strength of the concrete are not changed greatly. The reason may be that the addition of the silane coupling agent improves the bonding force between the hydrophobic layer and the reinforcing layer, so that the hydrophobic layer is not easy to fall off from the reinforcing layer, thereby further improving the workability of the concrete.

Drawings

Fig. 1 is a schematic view of the structure of recycled coarse aggregate in the present application.

In the figure, 1, a coarse aggregate body; 11. water-absorbing swelling filler particles; 12. a reinforcing layer; 13. a hydrophobic layer.

Detailed Description

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

The raw materials adopted by the application are all commercially available, wherein part of the raw materials are derived from the following sources:

the cement is P.O 42.5.5R available from Huarun Cement (seal open) Co., Ltd;

the fly ash is grade II fly ash purchased from Nanhaixin trade company Limited in Foshan city;

the fine aggregate is sand with the particle size range of 0.3-0.5mm purchased from Zhanjiang;

the water reducing agent is purchased from Huaxuan New Material Co., Ltd, in Foshan City, and has the model of FST-6;

the hydrophobic coating is GN-704 hydrophobic coating purchased from Guangzhou Yiner materials science and technology Limited;

the hydrophilic coating is a water-borne acrylic coating available from coma chemical ltd, guangzhou.

Preparation example

Preparation example 1

A kind of regenerated coarse aggregate, refer to fig. 1, including the coarse aggregate body 1 made of waste concrete, the water absorption that is packed in the pore space of the coarse aggregate body swells the filling particle 11, coat on the enhancement layer 12 of the peripheral side of the coarse aggregate body 11 and coat on the hydrophobic layer 13 outside the enhancement layer 12; the preparation method of the recycled coarse aggregate comprises the following steps:

step S1, filling the coarse aggregate body:

adding 400kg of water-absorbing expansion filling particles into 2000kg of coarse aggregate body, fully mixing uniformly and vibrating to ensure that the water-absorbing expansion filling particles enter pores of the coarse aggregate body to obtain a compact coarse aggregate body;

wherein, the water-absorbing swelling filling particles in the preparation example adopt polyacrylamide with the particle size range of 1-10 mu m.

Step S2, wrapping the reinforcing layer:

s2.1, adding 200kg of cement into 1000kg of water, and uniformly stirring to obtain cement paste;

and S2.2, adding 440kg of cement slurry into the compact coarse aggregate body to coat a layer of cement slurry on the outer peripheral side of the compact coarse aggregate body to obtain the reinforced coarse aggregate body.

Step S3, coating a hydrophobic layer:

and adding 800kg of hydrophobic coating into the reinforced coarse aggregate body to coat a layer of hydrophobic coating on the outer peripheral side of the reinforced coarse aggregate body, thus obtaining the recycled coarse aggregate.

Preparation example 2

A recycled coarse aggregate which is different from the recycled coarse aggregate prepared in the preparation example 1:

in the step S1, the dosage of the water-absorbing swelling filler particles is 500kg, and the water-absorbing swelling filler particles adopt carboxymethyl cellulose with the particle size range of 1-10 mu m;

in the step S2.1, the consumption of the cement is 400 kg;

the dosage of the cement paste in the step S2.2 is 540 kg;

the amount of the hydrophobic dope used in the step S3 was 1000 kg.

Preparation example 3

the particle size range of the water-absorbing swelling filler particles in the step S1 is 10-20 mu m.

Preparation example 4

A recycled coarse aggregate which is different from the preparation example 3 in that:

the particle size range of the water-absorbing swelling filler particles in the step S1 is 20-40 mu m.

Preparation example 5

step S2, wrapping the reinforcing layer:

s2.1, adding 50kg of silane coupling agent KH550 into 1000kg of water, and uniformly stirring to obtain a ready-mixed solution;

s2.2, adding 200kg of cement into the premixed liquid, and uniformly stirring to obtain cement paste;

and S2.3, adding 440kg of cement slurry into the compact coarse aggregate body to coat a layer of cement slurry on the outer peripheral side of the compact coarse aggregate body to obtain the reinforced coarse aggregate body.

Preparation example 6

A recycled coarse aggregate which is different from the recycled coarse aggregate prepared in the preparation example 5 in that: step S0 is preceded by step S1;

step S0, cleaning the coarse aggregate body:

and (4) adding the coarse aggregate body into water, cleaning the coarse aggregate body under the auxiliary action of ultrasonic waves, and filtering and drying the coarse aggregate body after the coarse aggregate body is cleaned up to be used as a spare material in the step S1.

Examples

The compositions and proportions of the high strength concrete with impermeability in examples 1 to 3 are shown in Table 1 below.

TABLE 1 composition and ratio (units/kg) of impervious high strength concrete in examples 1-3

Raw materials	Example 1	Example 2	Example 3
				Cement	448	448	448
Fly ash	72	65	76
				Fine aggregate	636	657	650
Recycled coarse aggregate	1089	1080	1071
				Water (W)	157	150	134
Water reducing agent	8.96	10.26	13.44

Example 1

An anti-permeability high-strength concrete is prepared by uniformly mixing cement, fly ash, fine aggregate, recycled coarse aggregate, water reducing agent FST-6 and water according to the proportion of example 1 in Table 1; in the present example, the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 1, and the continuous gradation of the recycled coarse aggregate was 5 to 25 mm.

Example 2

An anti-permeability high-strength concrete is prepared by uniformly mixing cement, fly ash, fine aggregate, recycled coarse aggregate, water reducing agent FST-6 and water according to the proportion of example 2 in Table 1; in the present example, the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 1, and the continuous gradation of the recycled coarse aggregate was 5 to 25 mm.

Example 3

An anti-permeability high-strength concrete is prepared by uniformly mixing cement, fly ash, fine aggregate, recycled coarse aggregate, water reducing agent FST-6 and water according to the proportion of example 3 in Table 1; in the present example, the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 1, and the continuous gradation of the recycled coarse aggregate was 5 to 25 mm.

Example 4

An impervious high strength concrete, which is different from example 1 in that: the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 2.

Example 5

An impervious high strength concrete, which is different from example 1 in that: the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 3.

Example 6

An impervious high strength concrete, which is different from example 1 in that: the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 4.

Example 7

An impervious high strength concrete, which is different from example 1 in that: the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 5.

Example 8

An impervious high strength concrete, which is different from example 1 in that: the recycled coarse aggregate was the recycled coarse aggregate prepared in preparation example 6.

Comparative example

Comparative example 1

A concrete, differing from example 1 in that:

the regenerated coarse aggregate is replaced by an equivalent coarse aggregate body made of waste concrete, and the continuous gradation of the coarse aggregate body is 5-25 mm.

Comparative example 2

A concrete, differing from example 1 in that:

in the recycled coarse aggregate, the outer peripheral side of the coarse aggregate body is directly coated with the hydrophobic layer.

Comparative example 3

A concrete, differing from example 1 in that:

in the recycled coarse aggregate, the hydrophobic layer is replaced by a hydrophilic layer made of hydrophilic coating.

Detection method/test method

And (3) anti-permeability grade: the concrete was tested for impermeability grade according to the 6.2 step-by-step pressurization method in GB/T50082-2009 standard for test methods for long-term performance and durability of ordinary concrete, and recorded in table 2 below.

28d compressive strength: the test is carried out according to the 6 th section compressive strength test in GB/T50081-2002 Standard method for testing mechanical properties of ordinary concrete.

Slump: pouring concrete into a horn-shaped slump bucket with an upper opening of 100mm, a lower opening of 200mm and a height of 300mm for three times, uniformly impacting 25 times along the wall of the bucket from outside to inside by using a tamping hammer after each filling, tamping and leveling. Then pulling up the barrel, wherein the concrete generates a collapse phenomenon due to self weight, and the height of the highest point of the collapsed concrete is subtracted by the height of the barrel to obtain the collapse degree; wherein the slump of the concrete suitable for pumping is 160-200 mm.

TABLE 2 Performance data for the concretes of examples 1-8 and comparative examples 1-3

Item	Example 1	Example 2	Example 3	Example 4
					Grade of impermeability	P8	P8	P8	P8
28d compressive strength/MPa	60.3	61.2	60.9	60.6
					Slump/mm	178	180	180	176
Item	Example 5	Example 6	Example 7	Example 8
					Grade of impermeability	P10	P8	P10	P10
28d compressive strength/MPa	60.8	61.1	61.3	63.5
					Slump/mm	181	179	198	200
Item	Comparative example 1	Comparative example 2	Comparative example 3
					Grade of impermeability	P4	P8	P8
28d compressive strength/MPa	30.6	33.6	50.9
					Slump/mm	170	173	108

Combining example 1 and comparative examples 1-3 with table 2, it can be seen that when other conditions are unchanged and waste concrete is directly used to replace recycled coarse aggregate, the concrete has better workability and is suitable for pumping, but the impermeability and compressive strength of the concrete are poorer; when other conditions are unchanged and the recycled coarse aggregate without the reinforcing layer is adopted, the concrete has better workability and impermeability, but the compressive strength of the concrete is poorer; when other conditions are unchanged and the recycled coarse aggregate without the hydrophobic layer is adopted, the impermeability and compressive strength of the concrete are better, but the workability of the concrete is poorer, and the concrete is not suitable for pumping.

It can be seen by combining example 1 and examples 5 to 6 and combining table 2 that example 5 to 6 are different from example 1 in the particle size of the water-absorbing expansive filler particles, wherein when the water-absorbing expansive filler particles with the particle size range of 10 to 20 μm are used, the impermeability of the concrete is further improved, because the water-absorbing expansive filler particles within the particle size range have good dispersibility and are not easy to agglomerate, and easily enter the pores of the waste concrete, which is beneficial to improving the compactness of the recycled coarse aggregate, thereby improving the compactness of the concrete and improving the impermeability of the concrete.

It can be seen by combining examples 5 and 7 and table 2 that example 5 differs from example 7 in that a silane coupling agent is added to the reinforcing layer of the recycled coarse aggregate in example 7, and by combining the data in table 1, the slump of the concrete in example 7 is further improved, and the impermeability and compressive strength of the concrete are not greatly changed, which indicates that the workability of the concrete is further improved and the concrete is easier to pump on the premise that the concrete maintains good impermeability and compressive strength; the reason for this may be that the addition of the silane coupling agent improves the bonding force between the hydrophobic layer and the reinforcing layer, so that the hydrophobic layer is not easily peeled off from the reinforcing layer, thereby further improving the workability of the concrete.

As can be seen from the combination of examples 7 to 8 and table 2, example 7 is different from example 8 in that the compressive strength of the concrete prepared in example 8 is further improved by firstly cleaning the coarse aggregate body for preparing the recycled coarse aggregate and then filling and coating the coarse aggregate body, and from the data in table 1, it is seen that the compressive strength of the concrete is further improved by adding the step of cleaning the coarse aggregate body. The reason may be that the washing step may remove some loose sludge in the coarse aggregate body and fill it with water-swellable particles, thereby improving the compressive strength of the concrete.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. The impervious high-strength concrete is characterized by comprising raw materials of cement, fly ash, sand, stone, water and a water reducing agent; the weight ratio of the cement, the fly ash, the fine aggregate, the regenerated coarse aggregate and the water is 1: (0.15-0.17): (1.42-1.47): (2.39-2.43): (0.30-0.35), wherein the mixing amount of the water reducing agent is 2-3% of the cement amount; the recycled coarse aggregate comprises a coarse aggregate body (1) made of waste concrete, water-absorbing expansion filling particles (11) filled in pores of the coarse aggregate body (1), a reinforcing layer (12) coated on the outer peripheral side of the coarse aggregate body (1) and a hydrophobic layer (13) coated on the outer side of the reinforcing layer (12); the reinforcing layer (12) is a cement paste layer.

2. The impervious high strength concrete according to claim 1, wherein the water-swellable filler particles (11) have a particle size in the range of 10 to 20 μm.

3. The impervious high-strength concrete as claimed in claim 1, wherein the water-swelling filler particles (11) are super absorbent resin, and the super absorbent resin is one or more of polyacrylamide, sodium polyacrylate and carboxymethyl cellulose.

4. The impervious high-strength concrete according to claim 1, wherein the preparation method of the recycled coarse aggregate comprises the following steps:

step S1, filling the coarse aggregate body (1): adding 400-500 parts by weight of water-absorbing expanded filler particles (11) into 2000 parts by weight of the coarse aggregate body (1), fully mixing uniformly and vibrating to ensure that the water-absorbing expanded filler particles (11) enter pores of the coarse aggregate body (1) to obtain a compact coarse aggregate body;

step S2, coating the reinforcing layer (12): adding 440-540 parts by weight of cement slurry into the compact coarse aggregate body to coat a layer of cement slurry on the outer peripheral side of the compact coarse aggregate body to obtain a reinforced coarse aggregate body;

step S3, coating the hydrophobic layer (13): and adding 800-1000 parts by weight of hydrophobic coating into the reinforced coarse aggregate body to coat a layer of hydrophobic coating on the outer peripheral side of the reinforced coarse aggregate body, thus obtaining the recycled coarse aggregate.

5. The impervious high-strength concrete according to claim 4, wherein the step S1 is further preceded by the step S0 of cleaning a coarse aggregate body: adding the coarse aggregate body (1) into water, cleaning the coarse aggregate body (1) under the auxiliary action of ultrasonic waves, and filtering and drying the coarse aggregate body (1) after cleaning the coarse aggregate body (1) to be used as a standby material in the step S1.

6. The impervious high-strength concrete according to claim 4, wherein the cement paste is prepared by the following steps:

firstly, adding 50-70 parts by weight of silane coupling agent into 1000 parts by weight of water, and uniformly stirring to obtain a ready-mixed solution; then adding 200-400 parts by weight of cement into the premixed liquid, and uniformly stirring to obtain the cement slurry.

7. The impervious high-strength concrete according to any one of claims 1 to 6, wherein the cement is P.O42.5R cement.

8. The impervious high strength concrete according to any one of claims 1 to 6, wherein said fly ash is class II fly ash.

9. The impervious high strength concrete according to any one of claims 1 to 6, wherein the fine aggregate has a particle size ranging from 0.3 to 0.5mm and the recycled coarse aggregate has a continuous gradation ranging from 5 to 25 mm.

10. The method for preparing anti-permeability high-strength concrete according to any one of claims 1 to 9, wherein the anti-permeability high-strength concrete is obtained by uniformly mixing cement, fly ash, fine aggregate, recycled coarse aggregate, water reducing agent and water according to a ratio.