CN112430044A

CN112430044A - Chlorine ion erosion resistant permeable recycled concrete and preparation method thereof

Info

Publication number: CN112430044A
Application number: CN202011463584.8A
Authority: CN
Inventors: 许广森; 俞裕星; 俞建松; 邹承忠
Original assignee: Shenzhen Hengxing Building Material Co ltd
Current assignee: Shenzhen Hengxing Building Material Co ltd
Priority date: 2020-12-11
Filing date: 2020-12-11
Publication date: 2021-03-02

Abstract

The application relates to the technical field of concrete, and particularly discloses permeable recycled concrete resistant to chloride ion corrosion and a preparation method thereof. The permeable recycled concrete resistant to chloride ion corrosion is prepared from the following raw materials in parts by weight: 300 parts of cement, 700 parts of 600 parts of sand, 1100 parts of crushed stone, 700 parts of recycled aggregate, 80-150 parts of fly ash, 60-100 parts of mineral powder, 70-120 parts of calcium carbonate, 50-100 parts of nano silicon dioxide, 40-80 parts of rubber powder, 30-50 parts of steel fiber, 5-7 parts of tackifier, 3-5 parts of water reducing agent and 230 parts of water 170; the preparation method comprises the following steps: and uniformly mixing the raw materials to obtain the recycled concrete. This application improves the compactedness in interface transition district and reduces the inside hole of concrete through reducing the interface effect between recycled aggregate and the grout, reduces the ability of chloride ion infiltration to improve the anti chloride ion of recycled concrete and corrode the performance.

Description

Chlorine ion erosion resistant permeable recycled concrete and preparation method thereof

Technical Field

The application relates to the technical field of concrete, in particular to permeable recycled concrete resistant to chloride ion corrosion and a preparation method thereof.

Background

With the rapid development of the building industry in China, the demand of gravels is more and more, a large amount of mountain mining and stone digging and sand washing are needed, and the ecological environment is seriously damaged. Meanwhile, the discharge amount of building wastes is increasing day by day, the resource utilization rate is low, and the waste concrete not only occupies valuable land, but also causes environmental and social problems, especially in large cities where the land and the space are in short supply. The concrete is prepared by crushing, cleaning, grading and mutually matching waste concrete according to a certain proportion, and the recycled aggregate is used as part or all of the aggregate, and is called recycled concrete.

The related technology is a Chinese patent with an authorization publication number of CN101407390B, and discloses a water-permeable cement concrete using recycled concrete as aggregate, which comprises the following raw material components in parts by weight: 400 portions of cement 250-; the inorganic cementing agent is one or more of silica fume, zeolite or metakaolin; the synthetic fiber is one or more of polypropylene fiber, polyacrylonitrile fiber or polyester fiber.

In view of the above-mentioned related technologies, the inventor believes that the interface action between the recycled concrete aggregate and the cement paste results in that the concrete in the interface transition region is not dense enough and cracks are easily generated at the interface, so that chloride ions are easily penetrated into the interface, the reinforcing steel bars in the concrete are corroded, and the strength of the building is reduced, and thus the concrete has a defect of poor resistance to chloride ion corrosion.

Disclosure of Invention

In order to improve the performance of the concrete against the corrosion of chloride ions, the application provides permeable recycled concrete against the corrosion of chloride ions and a preparation method thereof.

In a first aspect, the application provides a chlorine ion erosion resistant permeable recycled concrete, which adopts the following technical scheme:

the permeable recycled concrete resistant to chloride ion corrosion is prepared from the following raw materials in parts by weight: 300 parts of cement, 700 parts of sand 600, 1100 parts of gravel, 700 parts of recycled aggregate, 80-150 parts of fly ash, 60-100 parts of mineral powder, 70-120 parts of calcium carbonate, 50-100 parts of nano silica, 40-80 parts of rubber powder, 30-50 parts of steel fiber, 5-7 parts of tackifier, 3-5 parts of water reducing agent and 230 parts of water 170.

By adopting the technical scheme, cement and water form cement paste, the cement paste wraps the surfaces of the sand and the stone and fills gaps between the sand and the stone, and the cement paste plays a role in lubricating before the concrete is solidified and hardened, so that the concrete mixture has workability suitable for construction, and the hardened cement enables the concrete to have required strength. The sand and the stones are much cheaper than cement, the cost of the concrete is reduced as cheap filling materials, and in addition, the addition of the sand and the stones can improve the durability of the concrete and reduce adverse phenomena such as heating, drying shrinkage and the like of cement paste. By adopting the recycled aggregate, the production cost of the concrete can be reduced on one hand, and the recycling of the waste concrete is realized on the other hand. Nanometer silica and rubber powder are doped in a recycled concrete system, and the nanometer silica can effectively fill micro cracks between recycled aggregate and mortar, so that the number of capillary pores in the recycled concrete is reduced, the capillary pores are refined and curved, communicated pores are blocked better, and the performance of the recycled concrete against chloride ion erosion is improved. The rubber powder can reduce the pores in the recycled concrete, and the compactness is improved, so that the capability of resisting the corrosion of chloride ions is further improved. The steel fiber is distributed in the concrete and mutually wound to form a plurality of disorderly distributed fiber framework supporting systems, the system can reduce concrete bleeding, prevent added broken stones and the like from sinking, and reduce the original defects of the concrete, so that the homogeneity of the concrete is improved, the internal stress gradient of the concrete is reduced, the early cracks are prevented from being formed after the concrete is solidified, and the strength of the concrete after the concrete is solidified is improved.

Preferably, the preparation method of the recycled aggregate comprises the following steps: 1) cleaning the surface of the waste concrete to remove impurities on the surface of the waste concrete; 2) crushing and grading the cleaned waste concrete, and further ball-milling the crushed waste concrete to obtain particles with the particle size of 0.1-0.2 mm; 3) carrying out heat treatment on the particles obtained by grinding at the temperature of 400-900 ℃, wherein the heat treatment time is 1-2 h; 4) soaking the particles after heat treatment in alkali liquor, wherein the solid-liquid ratio of the particles to the alkali liquor is 1: 3-5; 5) and after soaking, drying to obtain the recycled aggregate.

By adopting the technical scheme, impurities such as soil attached to the surface of the waste concrete are cleaned, adverse effects caused by the impurities are avoided, the waste concrete is crushed and ball-milled into particles, the specific surface area of the recycled aggregate is improved, the activity of the wrapped material is released, then the particles obtained by ball milling are further subjected to heat treatment, the stable-form silicon-aluminum structure in the original waste concrete can be damaged, the waste concrete is converted into a metastable-state structure, and then the waste concrete is soaked in alkali liquor, the generation of gel substances is promoted in an alkaline environment, so that the hydration activity of the recycled aggregate is excited, the interface effect between the recycled aggregate and cement paste is reduced, the compactness of the concrete is improved, the generation of cracks after the concrete is solidified is reduced, and the anti-chlorine ion corrosion capability of the concrete is improved.

Preferably, the alkali solution in step 4) comprises at least one of a calcium hydroxide solution and a sodium hydroxide solution.

By adopting the technical scheme, the calcium hydroxide not only can provide an alkaline environment, but also can introduce a large amount of calcium ions to promote the generation of gel substances such as silicate and the like. Under the alkaline environment provided by sodium hydroxide, silicon-oxygen bonds and aluminum-oxygen bonds in the recycled aggregate are broken, the internal structure is recombined, and the condensation polymerization reaction is more easily carried out to generate a gel substance.

Preferably, in the alkali liquor in the step 4), the mass fraction of calcium hydroxide is 20-30wt%, and the mass fraction of sodium hydroxide is 15-20 wt%.

By adopting the technical scheme, the calcium hydroxide and the sodium hydroxide have an activating effect on the crushed and ground concrete, and the combined effect of the calcium hydroxide and the sodium hydroxide is better.

Preferably, the rubber powder is prepared by crushing waste tires, and the particle size is 50-100 meshes.

By adopting the technical scheme and adopting the waste tires, not only can the purpose of changing waste into valuable be achieved by recycling resources, but also the compactness of concrete can be enhanced, and the chloride ion corrosion resistance of the concrete can be improved.

Preferably, the tackifier comprises at least one of bentonite, cellulose ether and polyacrylamide.

By adopting the technical scheme, the bentonite is a layered silicate, swells to form flocculent substances after absorbing water, has good suspension property and dispersibility, is combined with a proper amount of water to form colloid, can release dotted particles in the water, and increases the viscosity of a concrete system. The cellulose ether enables polymer molecules to be intertwined, reduces the free movement space of each component particle, and improves the viscosity of a concrete system, thereby increasing the apparent concentration of the concrete. The polyacrylamide is added into the aqueous solution, so that the viscosity of the aqueous solution can be improved, the polyacrylic ester can adsorb water molecules around, and the adsorption and fixation of the polyacrylamide on the mixed water molecules promote the expansion of macromolecules, so that the viscosity of the mixed water and the viscosity of concrete are increased.

Preferably, the water reducing agent is lignosulfonate.

By adopting the technical scheme, the lignosulfonate is a natural high-molecular polymer and has strong dispersing capacity, and the surface tension and the interfacial tension of water can be reduced by adding the lignosulfonate into an aqueous solution. The lignosulfonate has hydrophobic groups and hydrophilic groups, the hydrophobic groups are directionally adsorbed on the surfaces of cement particles, and the hydrophilic groups point to an aqueous solution to form a monomolecular or polymolecular adsorption membrane, so that the cement particles are mutually repelled due to the same charges on the surfaces and are dispersed, and redundant water is released from the particles to achieve the purpose of reducing water.

Preferably, the fineness modulus of the sand is 2.5-2.8.

By adopting the technical scheme, the sand is too fine, so that the strength of the concrete after being solidified is reduced; the sand is too coarse, so that the compactness of the concrete is reduced, the concrete is easy to crack, and the performance of the concrete for resisting chloride ion corrosion is reduced.

Preferably, the particle size of the crushed stone is 5-31.5 mm.

By adopting the technical scheme, the strength of concrete can be reduced due to the fact that the particle size of the broken stone is too small; the particle size of the broken stone is too large, and the broken stone is easy to settle to the bottom of the stirring tank during concrete stirring, so that the performance of the prepared concrete is not uniform.

In a second aspect, the application provides a preparation method of permeable recycled concrete resistant to chloride ion corrosion, which adopts the following technical scheme:

a preparation method of permeable recycled concrete resistant to chloride ion corrosion specifically comprises the following steps:

s1, weighing the raw materials according to the formula, pouring cement, sand, broken stone, recycled aggregate fly ash, mineral powder, calcium carbonate, nano silicon dioxide, rubber powder and steel fiber into a stirrer, and uniformly mixing;

and S2, pouring water, the tackifier and the water reducing agent into the stirrer, and uniformly stirring to obtain the concrete.

By adopting the technical scheme, the recycled concrete can be prepared by uniformly stirring the raw materials, and the preparation method is simple.

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

1. as the nano-silica and the rubber powder are doped in the recycled concrete system, the nano-silica can effectively fill the microcracks between the recycled aggregate and the mortar, so that the number of capillary pores in the recycled concrete is reduced, the capillary pores are refined and curved, communicated pores are blocked better, and the chloride ion corrosion resistance of the recycled concrete is improved. The rubber powder can reduce the pores in the recycled concrete, and the compactness is improved, so that the capability of resisting the corrosion of chloride ions is further improved.

2. In the application, the steps of cleaning, crushing, heat treatment and soaking are preferably adopted, impurities such as soil attached to the surface of the waste concrete are cleaned, adverse effects caused by the impurities are avoided, the waste concrete is crushed and ball-milled into particles, the specific surface area of the recycled aggregate is improved, the activity of the wrapped material is released, then further carrying out heat treatment on the particles obtained by ball milling, destroying the stable-form silicon-aluminum body structure in the original waste concrete, converting the structure into a metastable-state structure, then soaking in alkali liquor, under the alkaline environment, the generation of gel substances is promoted, so that the hydration activity of the recycled aggregate is excited, the interface action between the recycled aggregate and cement paste is reduced, the compactness of the concrete is improved, the generation of cracks after the concrete is solidified is reduced, and the chloride ion corrosion resistance of the concrete is improved.

3. In the application, the waste tires are preferably adopted to prepare the rubber powder, so that the aim of changing waste into valuable by recycling resources can be achieved, the compactness of concrete can be enhanced, and the chloride ion corrosion resistance of the concrete can be improved.

Detailed Description

The present application will be described in further detail with reference to examples, in which the cement used in the present application is portland cement having a strength of 42.5, and the rubber powder is prepared by pulverizing waste tires.

Preparation example

Preparation example 1

The preparation method of the recycled aggregate comprises the following steps:

1) cleaning the surface of the waste concrete to remove impurities on the surface of the waste concrete;

2) crushing and grading the cleaned waste concrete, and further ball-milling the crushed waste concrete to obtain particles with the particle size of 0.1-0.2 mm;

3) carrying out heat treatment on the ground particles at 650 ℃, wherein the heat treatment time is 1 h;

4) soaking the particles after heat treatment in a calcium hydroxide solution with the mass fraction of 20wt%, wherein the solid-to-liquid ratio of the particles to alkali liquor is 1: 4;

5) and after soaking, drying to obtain the recycled aggregate.

Preparation example 2

The preparation method of the recycled aggregate comprises the following steps:

4) soaking the particles after heat treatment in a sodium hydroxide solution with the mass fraction of 20wt%, wherein the solid-to-liquid ratio of the particles to the alkali liquor is 1: 4;

5) and after soaking, drying to obtain the recycled aggregate.

Preparation example 3

The preparation method of the recycled aggregate comprises the following steps:

4) soaking the particles after heat treatment in a mixed solution of calcium hydroxide and sodium hydroxide, wherein the mass fraction of the calcium hydroxide is 20wt%, the mass fraction of the sodium hydroxide is 20wt%, and the solid-to-liquid ratio of the particles to the alkali liquor is 1: 4;

5) and after soaking, drying to obtain the recycled aggregate.

Preparation example 4

The method for preparing recycled aggregate is different from the preparation example 3 in that the heat treatment temperature in the step 3) is 400 ℃.

Preparation example 5

The method for preparing recycled aggregate is different from the preparation example 3 in that the heat treatment temperature in the step 3) is 900 ℃.

Examples

Example 1

Table 1 shows the raw materials and the quality of the permeable recycled concrete resistant to chloride ion corrosion in example 1

Raw materials	Mass (kg)	Raw materials	Mass (kg)
				Cement	200	Nano silicon dioxide	85
Sand	700	Rubber powder	40
				Crushing stone	1000	Steel fiber	40
Recycled aggregate	750	Bentonite clay	5
				Fly ash	80	Lignosulfonic acid sodium salt	3
S95 powdered ore	60	Water (W)	170
				Calcium carbonate	70

Wherein the fineness modulus of the sand is 2.5; the crushed stones are classified into 5-10mm accounting for 30%, 10-15mm accounting for 25%, 15-20mm accounting for 20%, 20-25mm accounting for 20% and 25-31.5mm accounting for 5%; the particle size of the rubber powder is 50 meshes; recycled aggregate was prepared for preparative example 1.

Example 2

A permeable recycled concrete resistant to chloride ion attack, which is different from example 1 in that recycled aggregate was prepared for preparation example 2.

A method for preparing permeable recycled concrete with resistance to chloride ion corrosion, which is the same as that in example 1.

Example 3

A permeable recycled concrete resistant to chloride ion attack, which is different from example 1 in that recycled aggregate was prepared for preparation example 3.

Example 4

Table 2 shows the raw materials and the quality of the permeable recycled concrete resistant to chloride ion corrosion in example 4

Raw materials	Mass (kg)	Raw materials	Mass (kg)
				Cement	250	Nano silicon dioxide	55
Sand	600	Rubber powder	80
				Crushing stone	1050	Steel fiber	30
Recycled aggregate	800	Cellulose ethers	5
				Fly ash	120	Lignosulfonic acid sodium salt	4
S95 powdered ore	80	Water (W)	200
				Calcium carbonate	90

Wherein the fineness modulus of the sand is 2.8; the crushed stones are classified into 5-10mm accounting for 30%, 10-15mm accounting for 25%, 15-20mm accounting for 20%, 20-25mm accounting for 20% and 25-31.5mm accounting for 5%; the particle size of the rubber powder is 50 meshes; recycled aggregate was prepared for preparation example 3.

Example 5

Table 3 shows the raw materials and the qualities of the permeable recycled concrete resistant to chloride ion corrosion in example 5

Raw materials	Mass (kg)	Raw materials	Mass (kg)
				Cement	300	Nano silicon dioxide	50
Sand	650	Rubber powder	60
				Crushing stone	1100	Steel fiber	50
Recycled aggregate	700	Bentonite clay	2
				Fly ash	100	Cellulose ethers	3
S95 powdered ore	100	Lignosulfonic acid sodium salt	3
				Calcium carbonate	110	Water (W)	210

Wherein the fineness modulus of the sand is 2.5; the crushed stones are classified into 5-10mm accounting for 30%, 10-15mm accounting for 25%, 15-20mm accounting for 20%, 20-25mm accounting for 20% and 25-31.5mm accounting for 5%; the particle size of the rubber powder is 80 meshes; recycled aggregate was prepared for preparation example 3.

Example 6

Table 4 shows the raw materials and the qualities of the water-permeable recycled concrete resistant to chloride ion corrosion in example 6

Raw materials	Mass (kg)	Raw materials	Mass (kg)
				Cement	280	Rubber powder	70
Sand	690	Steel fiber	50
				Crushing stone	1075	Bentonite clay	1
Recycled aggregate	770	Cellulose ethers	2
				Fly ash	130	Polyacrylamide	3
S95 powdered ore	90	Lignosulfonic acid sodium salt	3
				Calcium carbonate	95	Water (W)	210
Nano silicon dioxide	100

Wherein the fineness modulus of the sand is 2.8; the crushed stones are classified into 5-10mm accounting for 30%, 10-15mm accounting for 25%, 15-20mm accounting for 20%, 20-25mm accounting for 20% and 25-31.5mm accounting for 5%; the particle size of the rubber powder is 80 meshes; recycled aggregate was prepared for preparation example 3.

Example 7

Table 4 shows the raw materials and the qualities of the water-permeable recycled concrete resistant to chloride ion corrosion in example 7

Raw materials	Mass (kg)	Raw materials	Mass (kg)
				Cement	250	Rubber powder	60
Sand	655	Steel fiber	40
				Crushing stone	1055	Bentonite clay	3
Recycled aggregate	750	Cellulose ethers	2
				Fly ash	115	Polyacrylamide	2
S95 powdered ore	80	Lignosulfonic acid sodium salt	4
				Calcium carbonate	95	Water (W)	200
Nano silicon dioxide	75

Example 8

A permeable recycled concrete resistant to corrosion by chloride ions, which is different from example 7 in that recycled aggregate was prepared for preparation example 4.

Example 9

A water-permeable recycled concrete resistant to corrosion by chloride ions, which is different from example 7 in that recycled aggregate was prepared for preparation example 5.

Example 10

The permeable recycled concrete resistant to chloride ion corrosion is different from the permeable recycled concrete of example 7 in that the mass of the nano silica is 50kg, and the other steps are the same as those of example 7.

Example 11

The permeable recycled concrete resistant to chloride ion corrosion is different from the permeable recycled concrete of example 7 in that the mass of the nano silica is 100kg, and the other steps are the same as those of example 7.

Example 12

A chlorine ion erosion resistant water-permeable recycled concrete is different from example 7 in that the mass of the rubber powder is 40kg, and the other steps are the same as example 7.

Example 13

A chlorine ion erosion resistant water-permeable recycled concrete is different from example 7 in that the mass of the rubber powder is 80kg, and the other steps are the same as example 7.

Comparative example

Comparative example 1

The permeable recycled concrete with resistance to chloride ion corrosion is different from the permeable recycled concrete in example 7 in that nano-silica is not included in the raw materials, and the permeable recycled concrete is the same as the permeable recycled concrete in example 7.

Comparative example 2

The permeable recycled concrete with resistance to chloride ion corrosion is different from the permeable recycled concrete in example 7 in that rubber powder is not included in the raw materials, and the permeable recycled concrete is the same as the permeable recycled concrete in example 7.

Comparative example 3

The permeable recycled concrete with resistance to chloride ion corrosion is different from the permeable recycled concrete in the embodiment 7 in that the raw materials do not comprise nano silicon dioxide and rubber powder, and the other parts are the same as the embodiment 7.

Comparative example 4

The permeable recycled concrete with resistance to chloride ion corrosion is different from the permeable recycled concrete in example 7 in that the preparation method of the recycled aggregate comprises the following steps: 1) cleaning the surface of the waste concrete to remove impurities on the surface of the waste concrete; 2) crushing and grading the cleaned waste concrete, and further ball-milling the crushed waste concrete to obtain particles with the particle size of 0.1-0.2mm, namely the recycled aggregate; otherwise, the same procedure as in example 7 was repeated.

Comparative example 5

The permeable recycled concrete with resistance to chloride ion corrosion is different from the permeable recycled concrete in example 7 in that the preparation method of the recycled aggregate comprises the following steps: 1) cleaning the surface of the waste concrete to remove impurities on the surface of the waste concrete; 2) crushing and grading the cleaned waste concrete, and further ball-milling the crushed waste concrete to obtain particles with the particle size of 0.1-0.2 mm; 3) carrying out heat treatment on the ground particles at 650 ℃ for 1h to obtain recycled aggregate; otherwise, the same procedure as in example 7 was repeated.

Comparative example 6

The permeable recycled concrete with resistance to chloride ion corrosion is different from the permeable recycled concrete in example 7 in that the preparation method of the recycled aggregate comprises the following steps: 1) cleaning the surface of the waste concrete to remove impurities on the surface of the waste concrete; 2) crushing and grading the cleaned waste concrete, and further ball-milling the crushed waste concrete to obtain particles with the particle size of 0.1-0.2 mm; 3) soaking the particles in a mixed solution of calcium hydroxide and sodium hydroxide, wherein the mass fraction of the calcium hydroxide is 20wt%, the mass fraction of the sodium hydroxide is 20wt%, and the solid-to-liquid ratio of the particles to the alkali liquor is 1: 4, obtaining recycled aggregate; otherwise, the same procedure as in example 7 was repeated.

Performance test

Slump test: 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. And then pulling up the barrel, wherein the concrete generates a collapse phenomenon due to self weight, the height of the highest point of the collapsed concrete is subtracted from the barrel height (300mm), and the difference value is the slump.

Compressive strength: preparing a concrete test piece according to GB/T50081-2012 standard of a method for testing mechanical properties of common concrete, wherein the size of the concrete test piece is 100mm multiplied by 100mm, and testing the compressive strength after curing for a certain time;

and (3) testing the chloride ion penetration resistance: the test is carried out according to GB/T50082-2009 test method standard for long-term performance and durability of common concrete, and the chlorine ion permeation resistance of the concrete is reflected by the electric flux passing through the concrete.

TABLE 5 results of Performance test

It can be seen from the combination of examples 1-3 and table 5 that when the recycled aggregate prepared in preparation example 3 is applied to concrete, the compressive strength and the resistance to chloride ion corrosion of the prepared recycled concrete are the best, which indicates that the crushed and ground concrete can be activated by using calcium hydroxide and sodium hydroxide, and the combined effect of the calcium hydroxide and the sodium hydroxide is better.

It can be seen from examples 7 to 9 in combination with Table 5 that the activity of the recycled aggregate gradually increased with the increase in the heat treatment temperature, and that calcium hydroxide gradually decomposed and the activity of the recycled aggregate started to decrease as the temperature continued to increase, and that the addition of the recycled aggregate to the concrete reduced the generation of the gel-like substance, resulting in the deterioration of the properties of the recycled concrete.

Combining with the example 7, the examples 10 to 11 and the table 5, it can be seen that, with the increase of the nano silica, the nano silica can effectively fill the micro cracks between the recycled aggregate and the mortar, so that the number of the capillary pores in the recycled concrete is reduced, and the capillary pores are refined and curved, thereby better blocking the connected pores and improving the performance of the recycled concrete against the corrosion of chloride ions. When the nano silicon dioxide is increased continuously, the nano silicon dioxide is agglomerated and cannot be uniformly dispersed, so that the performance of the nano silicon dioxide on the recycled concrete is not obviously improved.

In combination with example 7, examples 12 to 13 and table 5, it can be seen that the increase of the rubber powder reduces the voids in the recycled concrete, increases the compactness, and further improves the resistance to chloride ion attack. The rubber powder is too much, and the interface action between the rubber powder and the inorganic cement paste is enhanced because the rubber powder belongs to a high polymer material, so that cracks are easy to appear in an interface transition area, the compressive strength of the recycled concrete is reduced, and the performance of resisting the corrosion of chloride ions is reduced.

In combination with example 7, comparative examples 1 to 3, and table 5, it can be seen that the synergistic effect between the nano silica and the rubber powder is more significant for improving the mechanical properties and the resistance to chloride ion corrosion of the recycled concrete.

In combination with example 7, comparative examples 4 to 6 and table 5, it can be seen that the recycled concrete can improve the activity of the recycled aggregate after heat treatment and soaking in alkali liquor, and the recycled aggregate is added into the concrete, so that the recycled aggregate reacts with cement slurry, the interface effect is reduced, the compactness of the interface transition region is improved, and the mechanical property and the chlorine ion corrosion resistance of the recycled concrete are improved.

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 utility model provides a recycled concrete permeates water of anti chlorine ion erosion which characterized in that: the feed is prepared from the following raw materials in parts by weight: 300 parts of cement, 700 parts of sand 600, 1100 parts of gravel, 700 parts of recycled aggregate, 80-150 parts of fly ash, 60-100 parts of mineral powder, 70-120 parts of calcium carbonate, 50-100 parts of nano silica, 40-80 parts of rubber powder, 30-50 parts of steel fiber, 5-7 parts of tackifier, 3-5 parts of water reducing agent and 230 parts of water 170.

2. The permeable recycled concrete resistant to chloride ion attack of claim 1, wherein: the preparation method of the recycled aggregate comprises the following steps: 1) cleaning the surface of the waste concrete to remove impurities on the surface of the waste concrete; 2) crushing and grading the cleaned waste concrete, and further ball-milling the crushed waste concrete to obtain particles with the particle size of 0.1-0.2 mm; 3) carrying out heat treatment on the particles obtained by grinding at the temperature of 400-900 ℃, wherein the heat treatment time is 1-2 h; 4) soaking the particles after heat treatment in alkali liquor, wherein the solid-liquid ratio of the particles to the alkali liquor is 1: 3-5; 5) and after soaking, drying to obtain the recycled aggregate.

3. The permeable recycled concrete resistant to chloride ion attack of claim 2, wherein: the alkali liquor in the step 4) at least comprises one of calcium hydroxide solution and sodium hydroxide solution.

4. The permeable recycled concrete resistant to chloride ion attack of claim 3, wherein: in the alkali liquor in the step 4), the mass fraction of the calcium hydroxide is 20-30wt%, and the mass fraction of the sodium hydroxide is 15-20 wt%.

5. The permeable recycled concrete resistant to chloride ion attack of claim 1, wherein: the rubber powder is prepared by crushing waste tires, and the particle size is 50-100 meshes.

6. The permeable recycled concrete resistant to chloride ion attack of claim 1, wherein: the tackifier at least comprises one of bentonite, cellulose ether and polyacrylamide.

7. The permeable recycled concrete resistant to chloride ion attack of claim 1, wherein: the water reducing agent is lignosulfonate.

8. The permeable recycled concrete resistant to chloride ion attack of claim 1, wherein: the fineness modulus of the sand is 2.5-2.8.

9. The permeable recycled concrete resistant to chloride ion attack of claim 1, wherein: the particle size of the crushed stone is 5-31.5 mm.

10. A method of producing water-permeable recycled concrete resistant to chloride ion attack according to any one of claims 1 to 9, characterized in that: the method specifically comprises the following steps: