CN112537932B

CN112537932B - Pervious concrete and construction method thereof

Info

Publication number: CN112537932B
Application number: CN202011535214.0A
Authority: CN
Inventors: 章华; 涂珊; 赵荣
Original assignee: Hubei Huatianyi Construction Engineering Co ltd
Current assignee: Hubei Huatianyi Construction Engineering Co ltd
Priority date: 2020-12-22
Filing date: 2020-12-22
Publication date: 2021-09-10
Anticipated expiration: 2040-12-22
Also published as: CN112537932A

Abstract

The application relates to the technical field of concrete, and particularly discloses pervious concrete and a construction method thereof. The pervious concrete comprises the following raw materials in parts by weight: 100 portions of water, 1300 portions of gravel, 1700 portions of cementing agent, 400 portions of cementing agent, 550 portions of polyurea, 150 portions of polyurea. The construction method comprises the following steps: s1: stirring and mixing; s2: paving and compacting; s3: removing the mold; s4: maintaining; s5: coating a sealing agent; s6: rolling and coating; performing roll coating of polyurea on the material treated by the S6; after the treatment of S6, the pervious concrete is obtained. Because this application adopts polyurea in the concrete that permeates water to make the compressive strength of the concrete that permeates water that finally obtains obtain the reinforcing.

Description

Pervious concrete and construction method thereof

Technical Field

The application relates to the technical field of concrete, in particular to pervious concrete and a construction method thereof.

Background

Pervious concrete is also called porous concrete, sand-free concrete and pervious terrace. Is a porous lightweight concrete which is prepared by mixing aggregate, cement, reinforcing agent and water, and does not contain fine aggregate. 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, so that the pervious concrete has the characteristics of air permeability, water permeability and light weight.

In the related art, the pervious concrete has a framework-pore structure after the subsequent construction is completed, so that the compressive strength of the pervious concrete is reduced compared with that of normal concrete although the pervious concrete has the functions of water and air permeability.

Disclosure of Invention

In order to solve the problem that the compressive strength of the pervious concrete is low, the application provides the pervious concrete and a construction method thereof.

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

the pervious concrete comprises the following raw materials in parts by weight: 100 portions of water, 1300 portions of gravel, 1700 portions of cementing agent, 400 portions of cementing agent, 550 portions of polyurea, 150 portions of polyurea.

By adopting the technical scheme, the structure of the pervious concrete is a framework-pore structure, so that the adhesive and the broken stone are in point contact. Meanwhile, under the condition that the permeable concrete pores exist, polyurea is coated and embedded into the tiny pores in the cross connection area of the cementing agent and the broken stones, so that the total bonding area between the broken stones and the cementing agent is increased. Meanwhile, the compactness of the concrete is correspondingly increased, so that the strength of the concrete is increased, and the compressive strength of the concrete can be increased finally. Polyurea has viscosity, can also increase the cementing strength between cementing agent and the rubble, has further improved the compressive strength of pervious concrete.

Preferably, the polyurea comprises a component A, a component B and a diluent, and the mass ratio of the component A to the component B is 10:10: 1;

each substance of the component A comprises 850 parts by weight of polyether polyol 750-;

each material of the component B comprises 700 parts by weight of polyether polyol 650-350 parts and diphenylmethane diisocyanate 300-350 parts.

By adopting the technical scheme, the polyether polyol is selected as the raw material for synthesis, so that the curing speed of finally obtained polyurea can be adjusted by adjusting the molecular weight of the polyether polyol, the finally obtained permeable concrete is wider in applicable environment and range, and the universality of the permeable concrete is enhanced.

Preferably, the component A also comprises 4 parts by weight of an ultraviolet resistant agent and 4 parts by weight of an antioxidant.

Preferably, the polyurea is a modified semi-polyurea; the modified semi-polyurea comprises a component A and a component B:

the component A comprises 850 parts by weight of polyaspartic acid ester 750-;

the component B comprises diphenylmethane diisocyanate;

the mass ratio of the addition amount of the component B to the addition amount of the component A is (1-2): 1.

By adopting the technical scheme, the modified semi-polyurea can be more fully embedded into tiny pores in the joint area of the cementing agent and the crushed stone. Because the gel time of modified half polyurea is longer itself, can reserve more sufficient engineering time for the staff, be favorable to simultaneously with the abundant inside of diffusing to the concrete that permeates water of modified half polyurea for modified half polyurea dispersed more even. The modified semi-polyurea can be more fully diffused into micro pores in the joint area of the cementing agent and the broken stone, so that the cementing force between the cementing agent and the broken stone is further increased, and the modified semi-polyurea has the property of polyurea, so that the compressive strength of the finally obtained permeable concrete can be further improved. On the other hand, the modified semi-polyurea has good adhesive force with the concrete, thereby prolonging the service life of the pervious concrete and keeping the pervious concrete with higher compressive strength for a longer time.

Preferably, the component A also comprises 40-60 parts by weight of cocamidopropyl lauryl ether, and the component B also comprises 20-40 parts by weight of bis-aminopropyl polydimethylsiloxane.

Through adopting above-mentioned technical scheme, through adding cocamidopropyl lauryl ether in modified half polyurea, can improve modified half polyurea's toughness, because the improvement that obtains of modified half polyurea own toughness, therefore the concrete that permeates water that finally obtains is when receiving the effort of external different directions, and its fragility reduces to the concrete that permeates water has reduced and has produced the possibility of crack. However, cocamidopropyl lauryl ether has poor compatibility with diphenylmethane diisocyanate and does not function, and the lubricity of diphenylmethane diisocyanate can be increased by adding bis-aminopropyl polydimethylsiloxane. The modified semi-polyurea can play a role in enhancing the toughness of the modified semi-polyurea in pervious concrete due to the increased compatibility between the cocamidopropyl lauryl ether and the diphenylmethane diisocyanate.

On the other hand, the modified semi-polyurea is added with the bis-aminopropyl polydimethylsiloxane, so that the steric effect of the polyurea can be increased, the reaction speed of-NCO can be reduced, and the action time of the modified semi-polyurea can be further prolonged.

Preferably, the cementing agent comprises 7-15% of silica fume, 4-10% of mineral powder, 7-13% of redispersible rubber powder, 20-30% of fly ash and the balance of portland cement by weight percentage.

By adopting the technical scheme, the portland cement is a common inorganic cementing material, is added with water and stirred to form slurry, can be hardened in the air or in water, and can firmly cement broken stones together. Fly ash, silica fume and mineral powder are active mineral admixtures, and reasonable grade pairing of the fly ash, the silica fume and the mineral powder in concrete reduces early hydration heat and reduces late shrinkage. The redispersible rubber powder can improve the mechanical property of the crushed stone and enhance the bonding strength between the portland cement and the crushed stone.

Preferably, the cementing agent comprises 20-35% of epoxy resin, 10-25% of silica fume and the balance of portland cement by weight percentage.

By adopting the technical scheme, cement is usually used as a cementing agent in the preparation process of the traditional concrete, so that the final concrete block is obtained. However, in the present application, since it belongs to the category of pervious concrete, there is no fine aggregate, and it belongs to the point contact that the broken stones and the broken stones are bonded together by the cementing agent. By adding the epoxy resin into the cementing agent, the fluidity of the cementing agent is enhanced compared with that of only cement and fly ash. The fluidity of the cementing agent is improved, so that the cementing agent can play a role in cementing.

By reasonably proportioning the silicate cement and the epoxy resin, the cementing agent has good fluidity to play the role of self cementing. On the other hand, the silicate cement has the function of bonding adjacent broken stones, and simultaneously can have certain strength after later maintenance is finished, and the strength advantage of the silicate cement can enhance the strength of the finally obtained pervious concrete after the silicate cement flows into the concrete.

Hardened Portland cement slurryDuring the course, Ca (OH) will be generated₂And Ca (OH)₂Whether the concrete is attached to the surface of broken stones or located in silicate cement stones, the strength of the pervious concrete is seriously reduced. The silica fume contains a large amount of SiO₂Capable of reacting with Ca (OH)₂The reaction produces C-S-H gel, effectively reducing Ca (OH)₂Influence on the strength of the pervious concrete.

The silica fume has extremely small particle size, and after being doped into cement, the early strength can be improved, and the later strength can be improved, so that the overall strength of the pervious concrete is improved.

Preferably, the cementing agent comprises 20-35% of epoxy resin, 7-15% of silica fume, 15-20% of polyvinyl acetal diethylaminoacetate and the balance of portland cement by weight percentage.

By adopting the technical scheme, the polyvinyl acetal diethylaminoacetate is added into the cementing agent, flows to all positions of the concrete broken stone aggregate under the condition of excellent fluidity of the cementing agent, is condensed in the pervious concrete and is interwoven with the silicate cement hydration product; in the presence of epoxy resin, polyvinyl acetal diethylaminoacetate forms a continuous polymer film in the hydration process of portland cement, and the area of contact points between the epoxy resin and the portland cement and broken stones is increased. And the polymer film and the silicate cement hydration product are embedded and filled with each other, so that the compactness of the cementing agent is improved. Meanwhile, due to the existence of polyvinyl acetal diethylaminoacetate, the viscosity of the cementing agent is increased, so that the bonding effect of the crushed stone and the cementing agent at the annual interface is increased.

When the polyurea contains the permeable concrete added with the cocamidopropyl lauryl ether, the permeable concrete is hydrated, and then the polyurea is coated on the permeable concrete after subsequent curing, and the permeable concrete is added with the polyvinyl acetal diethylaminoacetate and the epoxy resin, and the cocamidopropyl lauryl ether, the polyvinyl acetal diethylaminoacetate and the epoxy resin interact with each other, so that a layer of compact polymer film can be formed on the surface of the gravel in the permeable concrete on the premise of ensuring the water permeability of the permeable concrete, and the polymer film has the corrosion resistance; the crushed stone can be separated from the outside, so that the corrosion resistance of the finally formed pervious concrete is enhanced.

In a second aspect, the present application provides a construction method of pervious concrete, which adopts the following technical scheme:

the construction method of the pervious concrete comprises the following steps:

s1: stirring and mixing; mixing and stirring the crushed stone and the cementing agent according to a proportion amount to form a first mixture, adding a proportion amount of water into the first mixture, and continuously stirring and mixing for 2-8min to form a second mixture;

s2: paving and compacting; paving the second mixture in a mold, and tamping the material in the mold;

s3: removing the mold; s2, removing the mold after the material treated by the method lasts for 6-8 days, and then sprinkling water to the material after the mold is removed; s4: maintaining; continuously maintaining the material treated by the S3 for 24-30 days;

s5: coating a sealing agent; coating a sealing agent on the surface of the material treated by the S4;

s6: rolling and coating; performing roll coating of polyurea on the material treated by the S6; after the treatment of S6, the pervious concrete is obtained.

Preferably, after the S4 curing step, the material is heated to the surface temperature of 60-70 ℃ and then the surface of the material is coated with the modified semi-polyurea in a rolling way.

By adopting the technical scheme, when the pervious concrete is constructed and finally is subjected to roll coating, the concrete to be roll coated is heated to 60-70 ℃, and then the modified semi-polyurea is roll coated on the surface of the concrete, so that on one hand, the flow speed of the modified semi-polyurea can be accelerated, and simultaneously, the interaction of the cocamidopropyl lauryl ether, the polyvinyl acetal diethylaminoacetate and the epoxy resin in the polyurea can be promoted, and thus, a compact polymer film can be formed on the surface of the crushed stone in the pervious concrete more quickly. On the other hand, due to the concrete temperature rising operation, the compatibility between the cocamidopropyl lauryl ether and the diphenylmethane diisocyanate can be further improved, and finally the compressive strength of the polyurea to the pervious concrete can be improved.

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

1. because this application adopts polyurea in the concrete that permeates water to make the compressive strength of the concrete that permeates water that finally obtains obtain the reinforcing.

2. Polyether polyol is preferably adopted as a synthetic raw material in the application, so that the curing speed of finally obtained polyurea can be adjusted by adjusting the molecular weight of the polyether polyol, the finally obtained permeable concrete is applicable to a wider environment and range, and the universality of the permeable concrete is enhanced.

3. This application has adopted the half polyurea of modification to further improved pervious concrete and all can keep higher compressive strength in longer time.

4. According to the method, the pervious concrete to be roll-coated is heated to 60-70 ℃ before the polyurea is roll-coated, so that the compressive strength of the polyurea to the pervious concrete is further improved.

Drawings

FIG. 1 is a process flow diagram of the construction process of pervious concrete of the present invention.

Detailed Description

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

The raw material components of the invention are shown in the table 1:

TABLE 1

Example 1:

referring to fig. 1, a construction process of pervious concrete includes the following steps:

s1: stirring and mixing. 15kg of crushed stone and 4.75kg of cementing agent are conveyed to a concrete mixer by weight for mixing and stirring, and the stirring is continued for 1.5min to form a first mixture. Then 1.2kg of water was added to the first mixture and added in three equal portions, each with 10s intervals, and after the last addition of water was completed, the mixture was stirred continuously for 5min to form a second mixture. Wherein the cementing agent is Portland cement, and the crushed stone is crushed stone with the grain diameter of 4.75-9.5 mm.

S2: and paving and compacting. Pouring the second mixture into a mold, and then spreading the second mixture in the mold by a worker, followed by compacting the second mixture in the mold, controlling a coefficient of looseness within a range of 1.10 to 1.15, vibration-molding using a flat plate vibrator, and then covering an upper surface of the second mixture with a plastic film.

S3: and (6) removing the mold. The mould was removed after 6 days of application of the treated material at S2, and the covered plastic film was torn off and sprayed towards the material, which was then covered with plastic film.

S4: and (5) maintaining. Maintaining the material treated by the S3 for 24 days; the materials are sprayed with water every day, and the materials are covered with a plastic film immediately after being sprayed with water. And after the maintenance is finished, polishing and cleaning the surface laitance of the material.

S5: and coating a sealant. Coating a sealing agent on the surface of the material treated by the S4; the sealant is polyurethane sealing primer, and the dosage of the sealant is 0.2kg/m²。

S6: and (6) rolling and coating. After the sealant is cured, the material treated by S5 is coated with the B component of polyurea, then the diluent is mixed with the A component of polyurea, and then the A component mixed with the diluent is coated on the B component. Wherein each substance of the component A comprises 800 parts of polyether polyol, 150 parts of cross-linking agent, 4 parts of defoaming agent and 45 parts of plasticizer in parts by weight; each of the materials of the B component includes 675 parts by weight of polyether polyol and 325 parts by weight of diphenylmethane diisocyanate. Wherein the polyether polyol is polyoxypropylene glycol, and the molecular weight is 3000; the cross-linking agent is cyclohexane dimethanol, the defoaming agent is polydimethylsiloxane, the plasticizer is dioctyl terephthalate, and the diluent is ethyl acetate. The total roll-coating amount of polyurea was 2.25kg, and the mass ratio of the addition of the A component, the B component and the diluent was 10:10: 1.

After the treatment of S6, the pervious concrete is obtained.

Example 2:

the difference from example 1 is that in step S3, the mold was removed after the material treated in S2 lasted for 8 days.

S4: and (5) maintaining. Maintaining the material treated by the S3 for 30 days; the materials are sprayed with water every day, and the materials are covered with a plastic film immediately after being sprayed with water. And after the maintenance is finished, polishing and cleaning the surface laitance of the material.

Each substance of the a component of the polyurea in step S6 includes, in parts by weight, 800 parts of polyether polyol, 150 parts of a crosslinking agent, 4 parts of a defoaming agent, 45 parts of a plasticizer, 4 parts of an ultraviolet ray resistant agent, and 4 parts of an antioxidant.

Wherein, the polyether glycol is polyoxypropylene glycol, the cross-linking agent is cyclohexanedimethanol, the defoaming agent is polydimethylsiloxane, the plasticizer is dioctyl terephthalate, the ultraviolet resistant agent is UV-531 ultraviolet absorbent sold by Tatian litchi City Baoda Zinc titanium industry Co., Ltd, and the antioxidant is antioxidant 1076 sold by Tatian litchi City Baoda Zinc titanium industry Co., Ltd.

Example 3:

a construction process of pervious concrete comprises the following steps:

S3: and (6) removing the mold. The mold was removed after 7 days of the material treated in S2, and the covered plastic film was torn off and sprinkled towards the material, which was then covered with plastic film.

S4: and (5) maintaining. Continuously maintaining the material treated by the S3 for 27 days; the materials are sprayed with water every day, and the materials are covered with a plastic film immediately after being sprayed with water. And after the maintenance is finished, polishing and cleaning the surface laitance of the material.

S5: and coating a sealant. Coating a sealing agent on the surface of the material treated by the S4; the sealing agent is polyurethane sealing primer. And the amount of the sealing agent is 0.2kg/m²。

S6: and (6) rolling and coating. After the sealant is cured, the material treated by S5 is coated with the B component of polyurea, then the diluent is mixed with the A component of polyurea, and then the A component mixed with the diluent is coated on the B component.

The component A comprises 800 parts of polyaspartic acid ester, 4 parts of defoaming agent, 4 parts of flatting agent and 6 parts of accelerating agent by weight; the component B comprises diphenylmethane diisocyanate, and the mass ratio of the addition amount of the component B to the addition amount of the component A is 1.5: 1. Wherein the defoaming agent is polydimethylsiloxane, the leveling agent is sold by Shandongxinlonghui chemical import and export limited, and the accelerator is sold by Shangxing Yanglin new material limited, Shangxi 1305 accelerator. The total roll-on amount of the modified hemi-polyurea was 2.25 kg.

After the treatment of S6, the pervious concrete is obtained.

Example 4:

the differences from example 1 are as follows:

The surface of the material was then blown to a surface temperature of 65 ℃ using a blower, and 1.1kg of the modified semi-polyurea was then coated on the surface of the material. The modified semi-polyurea comprises a component A and a component B, wherein each substance of the component A comprises 800 parts of polyaspartic acid ester, 4 parts of defoaming agent, 4 parts of flatting agent and 6 parts of accelerating agent in parts by weight; the component B comprises diphenylmethane diisocyanate, and the mass ratio of the addition amount of the component B to the addition amount of the component A is 1.5: 1. When in coating, the component B is uniformly coated, and then the component A is coated on the component B. Wherein the defoaming agent is polydimethylsiloxane, the leveling agent is sold by Shandongxinlonghui chemical import and export limited, and the accelerator is sold by Shangxing Yanglin new material limited, Shangxi 1305 accelerator.

S5: and coating a sealant. Coating a sealing agent on the surface of the material treated by the S4; the sealing agent is polyurethane sealing primer.

S6: and (6) rolling and coating. After the sealant is cured, the component B of the modified semi-polyurea is brushed on the material, the component A of the polyurea is brushed on the component B after the component B is brushed uniformly, and the component A is brushed uniformly on the component B. The proportions of the modified semi-polyurea used in this step are the same as those of the modified semi-polyurea used in step S4. And the total amount of modified hemi-polyurea used in this step was 1.1 kg.

After the treatment of S6, the pervious concrete is obtained.

Example 5:

the difference from the example 4 is that in the curing step of S4, each substance of the component a includes, by weight, 800 parts of polyaspartic acid ester, 4 parts of antifoaming agent, 4 parts of leveling agent, 6 parts of accelerator, and 50 parts of cocamidopropyl lauryl ether; the component B comprises 30 parts of diphenylmethane diisocyanate and bis-aminopropyl polydimethylsiloxane, and the mass ratio of the addition amount of the component B to the addition amount of the component A is 1.5: 1.

Examples 6 to 9:

the difference from example 1 is that the raw material of the pervious concrete in the S1 mixing and polyurea in the S6 roll coating are shown in table 2 by mass. Unit: kg of

TABLE 2

	Example 6	Example 7	Example 8	Example 9
					Water (W)	1.0	1.4	1.1	1.3
Crushing stone	13	17	14	16
					Cementing agent	4.0	5.5	4.5	5.0
Polyurea	1.5	3.0	2.0	2.5

Examples 10 to 13:

the difference from example 5 is that the proportions of the substances of the modified semipolyurea are as shown in Table 3. Unit: portions are

TABLE 3

Examples 14 to 15:

the difference from example 4 is that the ratio of the amount of component B added to the amount of component A added in the modified semi-polyurea is shown in Table 4.

TABLE 4

Examples	Example 14	Example 15
			Mass ratio of	1:1	2:1

Example 16:

the difference from the example 1 is that the cementing agent in the stirring and mixing of the step S1 comprises 11% by weight of silica fume, 7% by weight of mineral powder, 10% by weight of redispersible rubber powder, 25% by weight of fly ash and 47% by weight of portland cement.

Examples 17 to 20:

the difference from the example 16 is that each chemical composition of the cementing agent in the stirring and mixing of the step S1 is shown in the following table 5 in weight percentage: is based on

TABLE 5

	Example 17	Example 18	Example 19	Example 20
					Silica fume	7	15	9	13
Mineral powder	4	10	6	8
					Redispersible rubber powder	7	13	8	12
Fly ash	20	30	23	28
					Portland cement	62	32	54	39

Example 21:

the difference from the example 1 is that the cementing agent in the stirring and mixing of the step S1 comprises 27.5 percent by weight of epoxy resin, 18 percent by weight of silica fume and the balance of portland cement.

Examples 22 to 25:

the difference from example 21 is that the binder in the stirring and mixing of step S1 is shown in table 6 in weight percent. Unit: is based on

TABLE 6

	Example 22	Example 23	Example 24	Example 25
					Epoxy resin	20	35	24	31
Silica fume	10	25	14	22
					Portland cement	70	40	62	47

Example 26:

the difference from the example 1 is that the cementing agent in the stirring and mixing of the step S1 comprises 27.5 percent by weight of epoxy resin, 11 percent by weight of silica fume, 17.5 percent by weight of polyvinyl acetal diethylamino acetate and the balance of portland cement.

Examples 27 to 30:

the difference from example 26 is that the binder in the stirring and mixing of step S1 is shown in Table 7 in weight percent. Unit: is based on

TABLE 7

Example 31:

the difference from the example 2 is that the cementing agent in the stirring and mixing of the step S1 comprises 27.5 percent by weight of epoxy resin, 18 percent by weight of silica fume, 17 percent by weight of polyvinyl acetal diethylaminoacetate and the balance of portland cement.

Example 32:

the difference from the example 3 is that the cementing agent in the stirring and mixing of the step S1 comprises 27.5 percent by weight of epoxy resin, 18 percent by weight of silica fume, 17 percent by weight of polyvinyl acetal diethylaminoacetate and the balance of portland cement.

Example 33:

the difference from the example 4 is that the cementing agent in the stirring and mixing of the step S1 comprises 27.5 percent by weight of epoxy resin, 18 percent by weight of silica fume, 17 percent by weight of polyvinyl acetal diethylaminoacetate and the balance of portland cement.

Example 34:

the difference from the example 5 is that the cementing agent in the stirring and mixing of the step S1 comprises 27.5 percent by weight of epoxy resin, 18 percent by weight of silica fume, 17 percent by weight of polyvinyl acetal diethylaminoacetate and the balance of portland cement.

Examples 35 to 37

The difference from example 4 is that in the curing of step S4, the surface of the material was blown to the surface temperature using a blower as shown in Table 8.

Unit: c

TABLE 8

Examples	Example 35	Example 36	Example 37
				Temperature of	60	70	63

Example 38

The difference from example 1 is that the polyether polyol in step S6 roll coating is a polyoxypropylene diol and has a molecular weight of 2000.

Example 39

The difference from example 1 is that the polyether polyol in step S6 roll coating is a polyoxypropylene diol and has a molecular weight of 5000.

Comparative example 1:

the difference from example 1 is that there is no step S6 roll coating.

Comparative example 2:

the difference from example 5 is that the bis-aminopropyl polydimethylsiloxane was absent from the B component.

Comparative example 3:

the difference from example 5 is that cocamidopropyl lauryl ether is absent from component a.

Comparative example 4:

the difference from example 5 is that the cement is free of epoxy.

Comparative example 5:

the difference from example 4 is that in the S4 curing step, the modified semi-polyurea was directly rolled onto the surface of the batch without heating the batch.

Comparative example 6:

the difference from example 1 is that the polyether polyol in step S6 roll coating is a polyoxypropylene diol and has a molecular weight of 1000.

Comparative example 7:

the difference from example 1 is that the polyether polyol in step S6 roll coating is a polyoxypropylene diol and has a molecular weight of 6000.

And (3) performance detection:

firstly, the concrete blocks obtained by the construction methods described in examples 1 to 39 and comparative examples 1 to 7 are subjected to bending strength, compression strength and water permeability coefficient test according to GB/T50080-2002 'test method for common concrete mixture performance' and CJJ/T135-2009 'technical Specification for permeable cement concrete pavement' on the manufactured standard test blocks, and the measured data are recorded in Table 9.

Secondly, corrosion resistance detection step one: preparing composite salt solution and composite salt solutionThe liquid is composed of MgSO 5 mass percent₄5% NaCl and 10% Na₂SO₄The volume ratio of the three solutions is 1:1: 1.

Step two: the concrete blocks obtained by the construction methods described in examples 1 to 39 and comparative examples 1 to 7 were prepared into standard test blocks according to GB/T50080-2002 "test method for general concrete mixture properties", the standard test blocks were then placed in the composite salt solution prepared in step one, respectively, to perform a dry-wet cycle durability test, the standard test blocks were sequentially soaked in the composite salt solution for 12 hours, then dried in an oven at 85 ℃ for 8 hours, repeated 50 times, and the final weight of the standard test blocks after the standard test blocks were saturated with water was measured, and the weight loss rate of the standard test blocks was calculated in a calculation manner of (final weight-basis weight)/basis weight, and is shown in table 9.

TABLE 9

And (3) data analysis:

as is apparent from table 9, in example 1, compared with comparative example 1, the compressive strength of the pervious concrete prepared by the technical scheme described in example 1 of the present application is significantly improved by adding polyurea during the construction process.

From the data on the compressive strength of examples 1 and 3, it can be concluded that the compressive strength of the pervious concrete can be improved by using the modified semi-polyurea.

From the data of the compressive strength of examples 3 and 4, it can be concluded that the compressive strength and the flexural strength of the pervious concrete can be improved by applying the modified semi-polyurea on the surface of the pervious concrete before applying the sealer.

From the data of examples 4 and 5, it can be concluded that the flexibility between the crushed stone and the cementing agent in the pervious concrete can be improved by adding cocamidopropyl lauryl ether and bis-aminopropylpolydimethylsiloxane to the modified semi-polyurea. When the pervious concrete is stressed, the flexibility between the broken stone and the cementing agent is improved, certain dislocation deformation can be generated between the broken stone and the cementing agent, and the broken stone and the cementing agent are not easy to break, so that the compressive strength and the bending strength of the pervious concrete are also improved to different degrees.

From the data of example 21 and example 1, it can be concluded that the water permeability of the pervious concrete can be improved compared to using only portland cement by replacing the cement with a cement containing an epoxy resin. Meanwhile, due to the existence of the epoxy resin, the flowability of the cementing agent can be enhanced, and the possibility that the cementing agent flows to tiny pores is higher, so that the compressive strength and the bending strength of the cementing agent are improved to different degrees.

As can be seen from the data of example 21 and example 26, the addition of polyvinyl acetal diethylaminoacetate to the cementitious agent can enhance the compactness of the cementitious agent and increase the viscosity of the cementitious agent, thereby increasing the strength of the action between the cementitious agent and the crushed stone, and finally increasing the compressive strength and the flexural strength of the pervious concrete obtained in example 26 to some extent.

The compressive strength of the pervious concrete test pieces prepared in example 32 was reduced because the mechanical properties of the pervious concrete test pieces were degraded because the modified semi-polyurea was not coated on the pervious concrete test pieces before the sealant was coated during the construction.

As can be seen from the comparison of example 34 with example 5, the compressive strength of example 32 is significantly improved because the binder used in example 32 contains polyvinyl acetal diethylaminoacetate. Under the condition that the polyvinyl acetal diethylaminoacetate exists in the cocamidopropyl lauryl ether, the polyvinyl acetal diethylaminoacetate and the epoxy resin interact with each other, a layer of compact polymer film can be formed on the surface of the gravel in the pervious concrete on the premise of ensuring the water permeability of the pervious concrete, and the connection strength between the gravel and the cementing agent is enhanced under the condition that the polymer film exists, so that the compression strength and the bending strength of the gravel are obviously improved.

Meanwhile, due to the polymer film, the corrosion resistance of the finally obtained permeable concrete test block is obviously improved. Since the epoxy resin was not present in the cement in example 5, the water permeability was relatively poor.

In example 34, as compared with example 33, since example 31 did not contain cocamidopropyl lauryl ether and a polymer film could not be formed, the solution described in example 31 could only improve the compressive strength of the pervious concrete sample to a certain extent, and could not significantly improve the flexural strength of the concrete sample and the corrosion resistance thereof.

Since each performance index was the most suitable for example 34, the pervious concrete obtained by the construction method described in example 32 was the most suitable in terms of flexural strength, compressive strength, water permeability and corrosion resistance.

From the data of example 5 and comparative example 2, it can be concluded that the modified hemi-polyurea has a drastic reduction in compressive and flexural strength due to the absence of bis-aminopropylpolydimethylsiloxane, which is due to the poor compatibility of cocamidopropyl lauryl ether with diphenylmethane diisocyanate, so that the modified hemi-polyurea does not improve the mechanical properties of pervious concrete.

The disadvantage of poor compatibility of cocamidopropyl lauryl ether and diphenylmethane diisocyanate is that cocamidopropyl lauryl ether, polyvinyl acetal diethylaminoacetate and epoxy resin cannot interact with each other, and finally a polymer film cannot be formed, so that the corrosion resistance of the pervious concrete is also poor.

From the data of example 5 and comparative example 4, it can be concluded that the lack of epoxy resin causes the poor fluidity of the cementing agent, so that the cementing agent cannot exert the maximum effect, and finally the mechanical property of the pervious concrete is reduced.

Meanwhile, the poor flowability of the cementing agent reduces the formation amount of the final compact polymer film, thereby reducing the corrosion resistance of the pervious concrete.

From the data of example 4 and comparative example 5, it can be concluded that heating the surface of the pervious concrete before applying the sealer increases the flow rate of the modified semi-polyurea, thereby allowing the surface of the crushed stone inside the pervious concrete to form a dense polymer film more quickly.

Meanwhile, due to the operation of raising the temperature of the surface of the concrete, the compatibility between the cocamidopropyl lauryl ether and the diphenylmethane diisocyanate can be further improved, and the compressive strength of the polyurea to the pervious concrete can be finally improved.

From the experimental data of example 1, example 38, example 39, comparative example 6 and comparative example 7, it can be seen that the curing speed of polyurea can be controlled by selecting different molecular weights, and when the molecular weight of polyoxypropylene glycol is 3000, the curing speed is the slowest, and sufficient time can be provided for the polyurea to enter into the pervious concrete, so that the compressive strength and the flexural strength of the polyurea are correspondingly improved. However, in examples 38 and 39, the curing speed is too fast, so that polyurea does not sufficiently enter the pervious concrete, and the compressive strength and the flexural strength of the pervious concrete cannot be maximized. The data of comparative examples 6 and 7 show that when the molecular weight of the polyoxypropylene diol is less than 2000 and greater than 5000, a good curing rate is not obtained, and thus the compressive strength and the flexural strength of the resulting pervious concrete are reduced.

From the data of the water permeability coefficients of comparative examples 6 and 7, it can be concluded that, when the molecular weight of polyoxypropylene glycol is lower than 2000 and higher than 5000, it has not reached the interior of concrete due to its too fast curing speed, but stays on the surface of the pervious concrete, thus affecting the water permeability of the pervious concrete.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The pervious concrete is characterized in that: the raw materials comprise the following components in parts by weight: 100 portions of water, 1300 portions of gravel, 1700 portions of cementing agent, 400 portions of cementing agent, 550 portions of polyurea and 300 portions of polyurea;

the polyurea is modified semi-polyurea; the modified semi-polyurea comprises a component A and a component B:

the component A comprises 850 parts by weight of polyaspartic acid ester 750-

4-9 parts of an accelerant;

the component B comprises diphenylmethane diisocyanate;

the mass ratio of the addition amount of the component B to the addition amount of the component A is (1-2) to 1;

the component A also comprises 40-60 parts by weight of cocamidopropyl lauryl ether, and the component B also comprises 20-40 parts by weight of bis-aminopropyl polydimethylsiloxane.

2. The pervious concrete of claim 1, wherein: the cementing agent comprises 7-15% of silica fume, 4-10% of mineral powder, 7-13% of redispersible rubber powder, 20-30% of fly ash and the balance of portland cement by weight percentage.

3. The pervious concrete of claim 1, wherein: the cementing agent comprises 20-35% of epoxy resin, 10-25% of silica fume and the balance of portland cement by weight percentage.

4. The pervious concrete of claim 1, wherein: the cementing agent is packaged by weight percentage

Comprises 20-35% of epoxy resin, 7-15% of silica fume, 15-20% of polyvinyl acetal diethylaminoacetate and the balance of portland cement.

5. The method for constructing a pervious concrete according to any one of claims 1 to 4, characterized in that: the method comprises the following steps:

s1: stirring and mixing; mixing and stirring the broken stone and the cementing agent according to the proportion to form a first mixture, and adding the first mixture into the first mixture

Adding water into the mixture, and continuously stirring and mixing for 2-8min to form a second mixture;

s3: removing the mold; the material treated by S2 is removed after lasting for 6-8 days, and then is directed to the material after the removal of the mould

Sprinkling water;

s4: maintaining; continuously maintaining the material treated by the S3 for 24-30 days;

s6: rolling and coating; performing roll coating of polyurea on the material treated by the S5; after S6 treatment, the pervious concrete is obtained

And (4) soil.

6. The construction method of pervious concrete according to claim 5, characterized in that: after the S4 curing step, the material is heated to the surface temperature of 60-70 ℃, and then the surface of the material is coated with the modified semi-polyurea in a rolling way.