1. The pervious concrete prepared from the recycled materials is characterized by being prepared from a concrete mixture, wherein the concrete mixture comprises the following components in parts by weight:

cement: 312 and 338 parts;

water: 105-126 parts;

fly ash: 45-68 parts of a stabilizer;

coarse aggregate: 748-830 parts;

recycled aggregate: 166-213 parts;

water reducing agent: 2-7 parts;

cocamidopropyl betaine: 1.2-1.6 parts;

triterpene saponins: 0.38-0.60 parts;

triisopropanolamine: 0.32 to 0.56 portion.

2. The pervious concrete prepared from recycled materials of claim 1, characterized in that: the concrete mixture comprises the following components in parts by weight:

cement: 321-326 parts;

water: 113-120 parts;

fly ash: 52-58 parts;

coarse aggregate: 775 and 815 parts;

recycled aggregate: 186 parts to 195 parts;

water reducing agent: 4-6 parts;

cocamidopropyl betaine: 1.3-1.5 parts;

triterpene saponins: 0.45-0.52 part;

triisopropanolamine: 0.42 to 0.48 portion.

3. The pervious concrete prepared from recycled materials of claim 1, characterized in that: the concrete mixture also comprises 0.2 to 0.5 weight part of sodium abietate.

4. The pervious concrete prepared from recycled materials of claim 1, characterized in that: the concrete mixture also comprises 0.15 to 0.22 weight portion of calcium thiosulfate.

5. The pervious concrete prepared from recycled materials of claim 1, characterized in that: the coarse aggregate is macadam with the average grain diameter of 10-15 mm.

6. A method for preparing pervious concrete prepared from recycled materials, which is based on the pervious concrete prepared from recycled materials in any one of claims 1-2 and 5, and is characterized by comprising the following steps:

step 1): stirring and mixing cement and fly ash to obtain a cementing material;

step 2): stirring and mixing water, cocamidopropyl betaine, triterpenoid saponin and triisopropanolamine to obtain a liquid material;

step 3): stirring and mixing the liquid material and the cementing material together to obtain slurry;

step 4): and stirring and mixing the slurry, the coarse aggregate and the recycled aggregate to obtain a finished product.

7. The method for preparing pervious concrete from recycled materials according to claim 6, wherein the recycled materials are selected from the group consisting of: in the step 2), 0.2-0.5 part by weight of sodium abietate is also added.

8. The method for preparing pervious concrete from recycled materials according to claim 6, wherein the recycled materials are selected from the group consisting of: in the step 2), 0.15-0.22 part by weight of calcium thiosulfate is also added.

Background

The pervious concrete is also called porous concrete, and is porous light concrete mixed by aggregate, cement, reinforcing agent and water. The pervious concrete is a cellular structure with uniformly distributed pores formed by coating a thin layer of cement slurry on the surface of coarse aggregate and bonding the thin layer of cement slurry, and has the characteristics of air permeability, water permeability and light weight.

The recycled material refers to any raw material which can be industrially recycled and reused through a certain processing process.

Along with the development of the urbanization process of China, the discharge amount of construction waste is increased year by year, and the proportion of renewable components is also continuously improved. In order to protect land and resources, the production and utilization of the construction waste recycled aggregate have important significance for saving resources, protecting the environment and realizing the sustainable development of the construction industry. The aggregate accounts for a relatively heavy proportion in the concrete, and the recycled aggregate is used to greatly contribute to environmental protection, so that a lot of projects begin to use the recycled aggregate at the present stage.

As the recycled aggregate is derived from the waste gas concrete, a certain amount of cement mortar exists on the surface, and the surface is rough and has edges and corners, so that the bulk density and the apparent density of the recycled aggregate are lower than those of the common concrete. And the porous structure of the pervious concrete further reduces the compressive strength of the concrete. This results in that pervious concrete doped with recycled aggregate cannot be used under the condition of requiring strength, and thus needs to be improved.

Disclosure of Invention

In order to improve the compressive strength of pervious concrete, the application provides pervious concrete prepared from reclaimed materials and a preparation method thereof.

In a first aspect, the application provides a pervious concrete prepared from recycled materials, which adopts the following technical scheme:

the pervious concrete prepared from the recycled materials is prepared from a concrete mixture, wherein the concrete mixture comprises the following components in parts by weight:

cement: 312 and 338 parts;

water: 105-126 parts;

fly ash: 45-68 parts of a stabilizer;

coarse aggregate: 748-830 parts;

recycled aggregate: 166-213 parts;

water reducing agent: 2-7 parts;

cocamidopropyl betaine: 1.2-1.6 parts;

triterpene saponins: 0.38-0.60 parts;

triisopropanolamine: 0.32 to 0.56 portion.

Cement: 321-326 parts;

water: 113-120 parts;

fly ash: 52-58 parts;

coarse aggregate: 775 and 815 parts;

recycled aggregate: 186 parts to 195 parts;

water reducing agent: 4-6 parts;

cocamidopropyl betaine: 1.3-1.5 parts;

triterpene saponins: 0.45-0.52 part;

triisopropanolamine: 0.42 to 0.48 portion.

By adopting the technical scheme, the coarse aggregate and the recycled aggregate form a framework, the cementing layer formed by cement, water, cocamidopropyl betaine, triterpenoid saponin and triisopropanolamine wraps the surface of the framework, the cementing layer is tightly connected with the framework, and the pores between the cementing layer and the framework are communicated, so that the water permeability is achieved.

Under the common coordination of the cocamidopropyl betaine, the triterpenoid saponin and the triisopropanolamine, various raw materials are closely associated, so that the water-permeable brick has water permeability and good compressive strength.

Specifically, the triterpene saponin consists of monosaccharide group, glycoside group and aglycone, wherein monosaccharide in the monosaccharide group has a plurality of hydroxyl groups, and carboxyl groups are also included in the cocamidopropyl betaine and can form hydrogen bonds with water molecules, so that the triterpene saponin has strong hydrophilicity. The inventor guesses that triisopropanolamine has certain influence on cocamidopropyl betaine and triterpenoid saponin, further enhances the combination degree of carboxyl and water molecules in the triterpenoid saponin and the cocamidopropyl betaine, reduces the tension on a gas-liquid interface, and can introduce a large amount of uniformly distributed, stable and closed micro bubbles in the process of stirring concrete, thereby increasing the fluidity and volume of slurry, increasing the compaction degree of the concrete and improving the compressive strength of the concrete.

In addition, triisopropanolamine has strong polarity and good dispersion effect due to the spatial and three-dimensional molecular structure, so that the triterpenoid saponin and the cocamidopropyl betaine can be more tightly and uniformly combined with water molecules, and a good particle dispersion effect can be achieved in cement, so that cement particles are not easy to agglomerate and are more tightly combined with coarse aggregates.

In conclusion, the concrete prepared from the concrete mixture has good compressive strength while having water permeability.

Preferably, the concrete mixture also comprises 0.2 to 0.5 weight part of sodium abietate.

Through adopting above-mentioned technical scheme, under the common cooperation of sodium abietate and cocamidopropyl betaine, triterpenoid saponin, further reduced the tension of gas-liquid interface, introduce more tiny bubble, also make the bubble of introducing distribute in the slurry more evenly simultaneously, further improve the compressive strength of concrete.

Preferably, the concrete mixture also comprises 0.15 to 0.22 weight part of calcium thiosulfate.

By adopting the technical scheme, under the matching of the calcium thiosulfate and the triisopropanolamine, the calcium thiosulfate can possibly change certain properties of the triisopropanolamine, so that the polarity of the triisopropanolamine is further enhanced, the influence of the triisopropanolamine on the cocamidopropyl betaine and the triterpenoid saponin is improved, and the compressive strength of the concrete is further improved.

Preferably, the coarse aggregate is crushed stone with the average particle size of 10-15 mm.

Through adopting above-mentioned technical scheme, adopt the rubble of this size within range, can improve the pore size of concrete for total porosity improves, and the coefficient of permeability increases, thereby improves the effect of permeating water.

In a second aspect, the application provides a preparation method of pervious concrete prepared from recycled materials, which adopts the following technical scheme:

a preparation method of pervious concrete prepared from reclaimed materials comprises the following steps:

step 1): stirring and mixing cement and fly ash to obtain a cementing material;

step 2): stirring and mixing water, cocamidopropyl betaine, triterpenoid saponin and triisopropanolamine to obtain a liquid material;

step 3): stirring and mixing the liquid material and the cementing material together to obtain slurry;

step 4): and stirring and mixing the slurry, the coarse aggregate and the recycled aggregate to obtain a finished product.

By adopting the technical scheme, water is stirred and mixed with the cocamidopropyl betaine, the triterpenoid saponin and the triisopropanolamine, the cocamidopropyl betaine and the triterpenoid saponin can be better connected with water molecules, then the obtained liquid material is stirred and mixed with the gelling material, most of water and cement form slurry in the stirring process, then the slurry can uniformly wrap coarse aggregate and regenerated aggregate, the bonding strength between the cement and other raw materials is improved, and the water permeability and the compressive strength of concrete are better improved.

Preferably, in the step 2), 0.2 to 0.5 part by weight of sodium abietate is also added.

By adopting the technical scheme, the sodium abietate is added in the step 2), and can be more closely matched with the cocamidopropyl betaine and the triterpenoid saponin, so that the water permeability and the compressive strength of the concrete are further improved.

Preferably, in the step 2), 0.15 to 0.22 part by weight of calcium thiosulfate is also added.

By adopting the technical scheme, the calcium thiosulfate is added in the step 2), and can be directly contacted and matched with triisopropanolamine, so that the polarity of the triisopropanolamine is further enhanced, and the water permeability and the compressive strength of concrete are further improved.

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

1. the coarse aggregate and the recycled aggregate form a skeleton, a cementing layer formed by cement, water, cocamidopropyl betaine, triterpenoid saponin and triisopropanolamine wraps the surface of the skeleton, the cementing layer is tightly connected with the skeleton, and pores between the cementing layer and the skeleton are communicated, so that the cement has water permeability.

2. Under the common cooperation of the cocamidopropyl betaine, the triterpenoid saponin and the triisopropanolamine, various raw materials are closely associated, so that the water-permeable brick has water permeability and good compressive strength.

Detailed Description

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

The information on the source of the raw materials used in the following examples and comparative examples is detailed in Table 1.

TABLE 1

Raw materials	Model number	Source information
			Recycled aggregate	/	Zhengzhou Weida refractory Co., Ltd
Cement	CA50-G6	Henan Hao building materials resistant Co., Ltd
			Fly ash	cw2-5	Lingshou county Chuangwei mineral product processing factory
Cocoamidopropyl betaine	DR foaming agent	Jinan dao melting chemical Co Ltd
			Naphthalene series high efficiency water reducing agent	DNF-C	Beijing Haiyan Xingye Concrete Admixture Sales Co.,Ltd.
Sodium gluconate water reducing agent	/	Suzhou Bogri chemical technology Co., Ltd
			Polycarboxylic acid water reducing agent	/	Jinan Hui Jingchuan commercial Co Ltd
Triterpene saponins	LA-8Q	Shandong Li-ang New Material science and technology Co Ltd
			Triisopropanolamine	55991	Grease Limited of Yangtze river, Nanjing
Rosin acid sodium salt	HZ003	Shandong Huangcata New Material Co Ltd
			Calcium thiosulfate	/	Jining Bai chemical industry Co Ltd

Examples

Examples 1 to 5

The pervious concrete prepared from the recycled materials is prepared from concrete mixture, and the preparation method of the pervious concrete prepared from the recycled materials comprises the following steps:

step 1): stirring cement and fly ash for 5 minutes at the rotating speed of 48r/min to obtain a gelled material;

step 2): stirring water, cocamidopropyl betaine, triterpenoid saponin and triisopropanolamine for 3 minutes at the rotation speed of 38r/min to obtain a liquid material;

step 3): stirring the liquid material and the cementing material for 6 minutes at the rotating speed of 55r/min, and mixing together to obtain slurry;

step 4): and stirring the slurry, the coarse aggregate and the recycled aggregate for 5 minutes under the condition of the rotating speed of 58r/min to obtain a finished product.

The water reducing agent is one of a polycarboxylic acid water reducing agent, a sodium gluconate water reducing agent and a naphthalene high-efficiency water reducing agent; the coarse aggregate is one of broken gravel or broken stone.

Wherein, the specific selection and dosage of each raw material are as shown in Table 2.

TABLE 2

Examples 6 to 8

The pervious concrete prepared from the reclaimed materials is different from the pervious concrete prepared in the example 5 in that sodium abietate is also added in the step 2), and the adding amount of the sodium abietate is shown in a table 3.

TABLE 3

Item	Example 6	Example 7	Example 8
				Input amount (kg)	0.2	0.4	0.5

Examples 9 to 11

The pervious concrete prepared from the reclaimed materials is different from the pervious concrete prepared in the example 5 in that calcium thiosulfate is also added in the step 2), and the adding amount of the calcium thiosulfate refers to a table 4.

TABLE 4

Item	Example 9	Example 10	Example 11
				Input amount (kg)	0.15	0.22	0.18

Example 12

A pervious concrete prepared from recycled materials is different from the pervious concrete prepared in example 5 in that macadam with the average particle size of 20mm is adopted as the coarse aggregate.

Example 13

The difference between the pervious concrete prepared from the reclaimed materials and the pervious concrete prepared from the embodiment 8 is that 0.18kg of calcium thiosulfate is also added in the step 2).

Comparative example

Comparative example 1

A pervious concrete prepared from recycled materials is different from example 5 in that cocamidopropyl betaine is replaced by equal amount of crushed stone with an average particle size of 13 mm.

Comparative example 2

A pervious concrete prepared from recycled materials is different from the pervious concrete prepared in example 5 in that triterpenoid saponin is replaced by equal amount of broken stones with the average particle size of 13 mm.

Comparative example 3

The pervious concrete prepared from the reclaimed materials is different from the pervious concrete prepared in example 5 in that triisopropanolamine is replaced by equal amount of broken stones with the average particle size of 13 mm.

Performance test

1. And (3) detecting the compressive strength: the concrete obtained in examples 1 to 13 and comparative examples 1 to 3 was tested according to GB/T50081-2019 "test method Standard for physical and mechanical Properties of concrete", and the obtained concrete was prepared into cubic test pieces of 150mm x 150 mm.

2. And (3) detecting porosity: the concrete obtained in examples 1 to 13 and comparative examples 1 to 3 was tested according to the test method of the concrete association of japan, and the obtained concrete was prepared into a cylindrical test piece having a diameter of 100mm by 200mm, and the mass of the test piece was changed after the test piece was immersed in water for 24 hours and then air-dried naturally for 24 hours to reach saturation surface dryness, and the porosity was calculated by a formula.

3. And (3) detecting the water permeability coefficient: the concrete obtained in examples 1 to 13 and comparative examples 1 to 3 was tested according to the water head method of the test method of the concrete association of japan, and the water permeability coefficient was calculated by making the obtained concrete into a cylindrical test piece having a diameter of 100mm x 200mm and dropping 30 seconds of water at a uniform speed under a water head of 200 mm.

The specific assay data for experiments 1-3 are detailed in tables 5-8.

TABLE 5

Categories of	Compressive strength (MPa)	Porosity (%)	Coefficient of water permeability (mm/s)
				Example 1	45.6	16.8	3.3
Example 2	44.3	16.2	3.1
				Example 3	46.1	17.0	3.6
Example 4	46.4	17.3	3.7
				Example 5	46.8	17.8	4.0
Comparative example 1	32.6	14.3	2.4
				Comparative example 2	33.1	14.6	2.7
Comparative example 3	32.9	14.7	2.8

As shown by comparing the test data of examples 1-5 with those of comparative examples 1-3 in Table 5, the concrete mixtures of examples 1-5 have better compressive strength and water permeability than those of comparative examples 1-3. The inventor guesses that the water permeability and the pressure resistance of the prepared concrete are improved under the coordination of the cocamidopropyl betaine, the triterpenoid saponin and the triisopropanolamine.

TABLE 6

Categories of	Compressive strength (MPa)	Porosity (%)	Coefficient of water permeability (mm/s)
				Example 5	46.8	17.8	4.0
Example 6	47.7	18.1	4.2
				Example 7	47.9	17.9	4.3
Example 8	48.5	18.0	4.3

As shown by comparing the test data of example 5 and examples 6 to 8 in Table 6, the compressive strength of the concrete obtained in examples 6 to 8 was better than that of example 5, and the water permeability of examples 6 to 8 was similar to that of example 5. The inventor guesses that the joint matching of the sodium abietate, the cocamidopropyl betaine and the triterpenoid saponin can reduce the tension of a gas-liquid interface, so that a large amount of tiny and uniform bubbles are introduced, and the compressive strength of the concrete is further improved.

TABLE 7

Categories of	Compressive strength (MPa)	Porosity (%)	Coefficient of water permeability (mm/s)
				Example 5	46.8	17.8	4.0
Example 9	47.5	18.0	4.3
				Example 10	47.8	18.3	4.4
Example 11	48.2	18.8	5.0

As shown by comparing the test data of example 5 and examples 9 to 11 in Table 7, examples 9 to 11 are superior to example 5 in both the compressive strength and the water permeability. The inventor guesses that under the matching of the calcium thiosulfate and the triisopropanolamine, the calcium thiosulfate can possibly change certain properties of the triisopropanolamine, so that the influence of the triisopropanolamine on the cocamidopropyl betaine and the triterpenoid saponin is improved, and the water permeation effect and the compressive strength are further improved.

TABLE 8

Categories of	Compressive strength (MPa)	Porosity (%)	Coefficient of water permeability (mm/s)
				Example 5	46.8	17.8	4.0
Example 12	45.6	18.0	4.1
				Example 13	49.8	19.1	5.4

From a comparison of the test data in Table 8 between example 5 and example 12, the compressive strength of the concrete prepared from the concrete mix of example 5 is better than that of example 12, indicating that the concrete prepared from the coarse aggregate having an average particle size of 10-15mm has better compressive strength while having a good void size.

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.