CN113582601A

CN113582601A - Sponge urban pervious concrete and construction process thereof

Info

Publication number: CN113582601A
Application number: CN202110992539.XA
Authority: CN
Inventors: 李炳
Original assignee: Shenzhen Yilicheng Construction Engineering Co ltd
Current assignee: Shenzhen Yilicheng Construction Engineering Co ltd
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2021-11-02

Abstract

The application relates to the field of building materials, and particularly discloses sponge urban pervious concrete and a construction process thereof. The sponge urban pervious concrete comprises the following substances in parts by weight: 30-50 parts of aggregate, 20-30 parts of cement, 3-5 parts of reinforcing agent, 1-2 parts of water reducing agent, 2-3 parts of foaming agent and 10-20 parts of water, wherein the reinforcing agent comprises fly ash and needle-shaped wollastonite; the construction process comprises the following steps: s1, pre-foaming; s2, preparing concrete; and S3, paving. The pervious concrete can be used in the fields of roads, bridges and the like, and has excellent water absorption and storage effects and better strength; in addition, the construction process of the application enables the foam to be more stable and uniform through a pre-foaming mode, and further enables the concrete to absorb water through the pores to be better.

Description

Sponge urban pervious concrete and construction process thereof

Technical Field

The application relates to the field of building materials, in particular to sponge urban pervious concrete and a construction process thereof.

Background

Sponge cities generally refer to cities with rainfall flood management systems. The rain and flood management system mainly can absorb water, store water, seep water and purify water when raining, and release the stored water when needed, so that rainwater can freely migrate in cities. The sponge city is provided with a water-absorbing sponge body which comprises water systems such as rivers and lakes, city supporting buildings such as greenbelts, gardens, permeable pavements and the like; as the distribution of the pavement in the city is wide, the permeable pavement has important significance in the sponge city.

Permeable pavements are usually constructed using pervious concrete. Pervious concrete, also called porous concrete, is a porous lightweight concrete, and because the pervious concrete has many pores, the strength of the pervious concrete is not good, so in order to improve the strength of the pervious concrete, a reinforcing agent is usually added into the concrete to improve the strength of the pervious concrete.

In view of the above-mentioned related technologies, the inventors believe that simply adding a reinforcing agent to the pervious concrete causes the reinforcing agent to agglomerate easily, and then the reinforcing agent fills the pores of the pervious concrete, so that the concrete obtains a non-uniform reinforcing effect, resulting in the defect of poor strength of the concrete.

Disclosure of Invention

In order to improve the not good defect of concrete strength, this application provides a sponge city concrete and construction process that permeates water, adopts following technical scheme:

in a first aspect, the application provides a pervious concrete for sponge cities, which adopts the following technical scheme:

the sponge urban pervious concrete comprises the following substances in parts by weight: 30-50 parts of aggregate, 20-30 parts of cement, 3-5 parts of reinforcing agent, 1-2 parts of water reducing agent, 2-3 parts of foaming agent and 10-20 parts of water, wherein the reinforcing agent comprises fly ash and wollastonite, the mass ratio of the fly ash to the wollastonite is 1:0.5-2, and the wollastonite is needle-shaped wollastonite.

By adopting the technical scheme, the fly ash and the needle-shaped wollastonite are compounded to be used as the reinforcing agent, the needle-shaped wollastonite is in a fibrous structure, and then the concrete base material can be connected and pulled, and meanwhile, the needle-shaped wollastonite has better dispersibility, so that the fly ash is loaded on the needle-shaped wollastonite, the dispersing effect of the reinforcing agent in the concrete is improved, and the concrete obtains a more uniform and stable strength effect. Because the surface activity of the needle-shaped wollastonite is better, the needle-shaped wollastonite can be slightly crosslinked with the fly ash, so that the fly ash is stably loaded on the needle-shaped wollastonite. Meanwhile, as the fly ash has more pores, the porosity of the concrete is further improved and the water permeability effect of the concrete is enhanced while the reinforcing agent is dispersed in the concrete, so that the concrete obtains more uniform strength and water permeability effect.

Preferably, the reinforcing agent is a reinforcing agent subjected to modification treatment, and the modification treatment includes crosslinking treatment including the steps of: taking redispersible latex powder and water, stirring and mixing to obtain a crosslinking treatment solution, and mixing the crosslinking treatment solution and a reinforcing agent according to a mass ratio of 2-3: 1 stirring and mixing to obtain the reinforcing agent after crosslinking treatment.

By adopting the technical scheme, the reinforcing agent is modified by crosslinking treatment, so that the base materials of the reinforcing agent are stably connected, namely the fly ash is stably loaded on the surface of the acicular wollastonite, and the dispersibility of the redispersible latex powder in the concrete is better, so that the dispersion effect of the reinforcing agent coated with the redispersible latex powder in the concrete is improved, and the uniform and stable strength is further provided for the concrete. Because the reinforcing agent is coated with the redispersible latex powder, the redispersible latex powder participates in the concrete and promotes the gelation reaction, so that a staggered net structure can be formed between the reinforcing agent and the redispersible latex powder, the reinforcing agent and the redispersible latex powder are stably connected, the reinforcing agent is ensured to obtain a stable dispersion effect, and meanwhile, the connection stability of the reinforcing agent to the concrete base material is improved.

Preferably, the modification treatment further comprises a strengthening treatment, and the strengthening treatment further comprises the following steps: (1) acid washing: according to the mass ratio of 5-8: 1, taking hydrochloric acid and a reinforcing agent in a formula, stirring and mixing, heating, continuously reacting for 2-4 hours, filtering, retaining a filter cake, washing the filter cake until a washing liquid is neutral, and drying the filter cake at 35 ℃ to obtain the acid-washed reinforcing agent; (2) coating: according to the mass ratio of 2-3: 1, taking silica sol and the reinforcing agent pickled in the step (1), stirring and mixing to prepare a mixed solution, adding ammonia water into the mixed solution, continuously stirring, controlling the gelling temperature to prepare a gel solution, drying the gel solution at 40-60 ℃ in vacuum to prepare a dried product, and roasting to prepare the reinforcing agent subjected to strengthening treatment.

By adopting the technical scheme, the reinforcing agent is subjected to acid washing treatment, so that the specific surface area and the surface activity of the reinforcing agent are improved, the connection effect between the reinforcing agent and the concrete base material is improved, and the strength of the concrete is improved. The silica sol and the reinforcing agent are mixed, so that the silica sol can be uniformly coated outside the reinforcing agent, and the silica sol coats the pores of the reinforcing agent synchronously while coating the outer surface of the reinforcing agent, so that silica is loaded in the pores of the reinforcing agent after modification treatment, the silica forms a thin coating layer on the inner walls of the pores of the reinforcing agent, the possibility of pore collapse in the reinforcing agent is reduced, the stability of the pores of the reinforcing agent is maintained, and the effect of improving the porosity of concrete through the reinforcing agent is kept stable. Therefore, the strength of the reinforcing agent is improved, the reinforcing effect of the reinforcing agent on concrete is enhanced, and the strength of the concrete is improved; and the water permeability effect of the concrete is also improved.

Preferably, the gelling temperature in the step (2) is 20-50 ℃, the roasting treatment temperature is 800-1200 ℃, and the roasting treatment time is 1-3 h.

By adopting the technical scheme and adjusting the gelling temperature, on one hand, the gelling reaction between the silica sol and the reinforcing agent is relatively complete, the connection effect between the silica sol and the reinforcing agent is improved, and the strength of the reinforcing agent is stably improved through the silica sol; on the other hand, the silica sol can form an infrared-like reflection structure on the surface of the reinforcing agent, so that the structural strength is enhanced, and the strength of the reinforcing agent is further improved. Through roasting treatment, the strength of the infrared-like reflection structure is further improved, the supporting strength of silica sol to the pores of the reinforcing agent is improved, the reinforcing agent is enabled to stably provide the porosity for the concrete, namely, the water permeability of the concrete is guaranteed, and the concrete doped with the reinforcing agent obtains better strength.

Preferably, the foaming agent comprises sodium dodecyl sulfate and cocamidopropyl betaine, and the mass ratio of the sodium dodecyl sulfate to the cocamidopropyl betaine is 1: 2-5.

By adopting the technical scheme, the foaming agent is prepared by compounding sodium dodecyl sulfate and cocamidopropyl betaine, and the foaming effect and the foaming efficiency of the foaming agent are improved by compounding the anionic foaming agent and the amphoteric foaming agent. Meanwhile, the dispersing effect of the foaming agent in the concrete is good, so that the concrete obtains uniform pores, and the water permeation effect and the strength of the concrete are improved. In addition, because the activity of foaming agent promotes to some extent for the in-process that foaming agent and concrete mix, foaming agent and reinforcing agent can take place the certain degree and be connected, improve the connection effect between foam and the concrete, keep the concrete mesopore stable, and the reinforcing agent can support for the pore in the concrete to a certain extent, further ensure the stability of concrete mesopore.

Preferably, the foaming agent is a stabilized foaming agent, and the stabilizing treatment comprises the following steps: (1) respectively weighing the following substances in parts by weight: 3-5 parts of nano silicon dioxide, 10-15 parts of sodium hydroxide solution, 1-2 parts of stabilizer and 4-8 parts of foaming agent; (2) and (3) stable modification: taking nano silicon dioxide and sodium hydroxide solution according to a formula, stirring and mixing, carrying out ultrasonic treatment for 15-30min to prepare dispersion liquid, adding a foaming agent into the dispersion liquid, controlling the pH =10-11, stirring at a constant temperature of 15-30 ℃, carrying out 2-4h to prepare mixed solution, adding a stabilizing agent into the mixed solution, and continuously stirring and mixing to prepare the foaming agent subjected to stabilizing treatment.

By adopting the technical scheme, sodium hydroxide and nano-silica are mixed firstly, so that oxygen ions are generated by the initiation of the silica, the nano-silica is uniformly dispersed in the sodium hydroxide through ultrasonic treatment, and then the dispersion liquid is mixed with the foaming agent, so that hydrothermal synthesis can be generated between the foaming agent and the nano-silica, the bonding effect of the foaming agent is improved, and the bonding effect between foam and a concrete base material after the foaming agent is foamed is improved; meanwhile, the nano silicon dioxide can wrap the bubbles, so that on one hand, the stability of the foam is guaranteed, the defoaming possibility is reduced, and after the concrete and the foam are mixed, the foam provides pores for the stability of the concrete and guarantees the water permeation effect of the concrete; on the other hand, the nano silicon dioxide can be subjected to a gelation reaction with the concrete base material to generate hydrated gel, so that the combination effect between the foam and the concrete base material is further improved. In addition, after the concrete is cured, the air bubbles are broken, pores are formed in the concrete, and at the moment, the nano silica coated outside the air bubbles is loaded on the inner walls of the pores to support the pores formed by the foam, so that the possibility of pore collapse is reduced, and the strength of the concrete is further enhanced.

Preferably, the stabilizer comprises one or two of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose.

By adopting the technical scheme, as the hydroxypropyl methyl cellulose has a better dispersion effect, the dispersion effect of the foam formed by the foaming agent in the concrete is improved, so that the concrete obtains more uniform pores, and the strength of the concrete is improved. Because the sodium carboxymethyl cellulose is used as the ionic cellulose ether, the hydrophilic effect is better, water is absorbed in the concrete mixing process, the water is released in the concrete curing process, the internal curing is carried out on the concrete, and the strength of the concrete is further enhanced. Through compounding of hydroxypropyl methyl cellulose and sodium carboxymethyl cellulose, thickening and bonding effects of the stabilizer are improved, viscosity of the foaming agent is improved, and then a combination effect between the foam and a concrete base material is improved, stability of foam formed by the foaming agent is enhanced, and stability of pores provided for concrete by the foam is guaranteed.

In a second aspect, the application provides a construction process of pervious concrete for sponge cities, which adopts the following technical scheme:

a construction process of sponge city pervious concrete comprises the following steps: s1, pre-foaming: taking a foaming agent and water according to the formula, stirring and mixing for 3-5min to prepare foam; s2, concrete preparation: mixing cement, aggregate and a reinforcing agent by stirring to obtain a mixture, adding a water reducing agent and water into the mixture, continuously stirring and mixing to obtain mixed slurry, and stirring and mixing the foam obtained in the step S1 with the mixed slurry to obtain concrete; s3, paving: and uniformly paving the concrete on the template, uniformly vibrating, standing and curing.

Through adopting above-mentioned technical scheme, adopt the mode of prefoaming for the foaming agent evenly contacts with water, improves the homogeneity and the stability of the foam that makes, mixes foam and other substrates of concrete again, makes the foam steady provide the porosity for the concrete, ensures that the concrete obtains the effect and the homogeneous intensity of permeating water of preferred.

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

1. as the coal ash and the wollastonite are compounded to be used as the reinforcing agent, the coal ash can be loaded on the wollastonite, and the wollastonite has a better dispersion effect, so that the dispersion effect of the reinforcing agent in concrete is improved, the reinforcing agent is uniformly connected with base materials in the concrete, and the concrete obtains more uniform strength; meanwhile, the fly ash has better porosity, so that the porosity of the concrete is improved, and the water permeability effect of the concrete is further improved, so that the concrete obtains better water permeability effect and uniform strength effect.

2. In the application, the reinforcing agent is preferably modified, so that the connection between wollastonite and fly ash is more stable, the dispersion effect of the reinforcing agent in concrete is further improved, the reinforcing agent can be uniformly distributed in the concrete, and the concrete base material is connected, so that the strength of the concrete is improved; meanwhile, the silica sol is coated outside the reinforcing agent, so that the bonding effect between the reinforcing agent and the concrete base material is improved, the reinforcing agent stably reinforces the concrete, the inner wall of the pore of the reinforcing agent is coated and reinforced, the strength of the reinforcing agent is improved, and the strength of the concrete is further improved, so that the concrete obtains a relatively uniform strength effect.

3. The process of the application is characterized in that the foaming agent is fully contacted with water in a pre-foaming mode to generate uniform and stable foam, and the foam is compounded with other base materials of concrete to stably provide pores for the concrete, so that the concrete obtains a better water permeation effect and a more uniform strength effect.

Detailed Description

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

In the embodiment of the present application, the selected apparatuses are as follows, but not limited thereto:

the instrument comprises the following steps: JS500 type blender of Zheng Zhou Xing navigation mechanical equipments, TYMFS-0.75kw type high-speed disperser of Tao Yu (Shanghai) mechanical science and technology, and ZYG-1 type oven of Yu industrial electric furnace factory in Xinghua city.

Medicine preparation: polypropylene fiber of Shandongtong wood Co, Inc. with the product number of 444, and dodecanol of Shanghai Dongtong soil chemical industry import and export Co, Inc. with the product number of 027.

Preparation example

Preparation example of reinforcing agent

Preparation examples 1 to 3

Taking needle-shaped wollastonite and fly ash, stirring and mixing to prepare the reinforcing agent 1-3. The masses of the acicular wollastonite and the fly ash are shown in Table 1.

TABLE 1 Components of enhancers in preparation examples 1-3

Preparation examples 4 to 6

The difference from preparation example 2 is that: the reinforcing agent is a reinforcing agent subjected to modification treatment, the modification treatment comprises strengthening treatment, and the strengthening treatment comprises the following steps: 1kg of reinforcing agent 1 is firstly placed in 6kg of hydrochloric acid with the mass fraction of 10 percent; stirring and mixing, heating to 80 ℃, continuously reacting for 3 hours, stopping heating, filtering, retaining a filter cake, carrying out deionized washing until a washing liquid is neutral, transferring the filter cake to a drying oven, and drying at 35 ℃ to obtain the acid-washed reinforcing agent 1. Taking the acid-washed reinforcing agent and silica sol, wherein the specific mass is shown in Table 5, stirring and mixing the acid-washed reinforcing agent and the silica sol to prepare a mixed solution, adding ammonia water into the mixed solution, stirring to a gel state, controlling the gel temperature to be 20 ℃ to prepare a gel solution, and placing the gel solution in a vacuum drying oven at 50 ℃ to prepare a dried product; and placing the dried product in a resistance furnace, roasting at 800 ℃, grinding and sieving for 800 meshes to obtain the reinforcing agent 4-6 subjected to strengthening treatment, wherein the rest preparation conditions and preparation environment are the same as those of the preparation example 2.

TABLE 2 quality of reinforcing agent and silica sol in preparation examples 4 to 6

Preparation example 7

The difference from preparation 6 is that: the gel temperature is controlled to be 30 ℃, the roasting temperature is controlled to be 1000 ℃, the roasting treatment is carried out for 2 hours, the reinforcing agent 7 is prepared, and the other preparation conditions and the preparation environment are the same as those of the preparation example 6.

Preparation example 8

The difference from preparation 6 is that: the gel temperature is controlled to be 40 ℃, the roasting temperature is controlled to be 1200 ℃, the roasting treatment is carried out for 3 hours, the reinforcing agent 8 is prepared, and the other preparation conditions and the preparation environment are the same as those of the preparation example 6.

Preparation example 9

The difference from preparation example 7 is that: the reinforcing agent is a reinforcing agent subjected to modification treatment, the modification treatment comprises cross-linking treatment, and the cross-linking treatment comprises the following steps: respectively taking 1kg of redispersible latex powder and 2kg of water, and stirring and mixing to prepare a crosslinking treatment solution; then, 2kg of the crosslinking treatment solution and 1kg of the reinforcing agent 6 were mixed under stirring to prepare a crosslinked modified reinforcing agent 9, and the other preparation conditions and the preparation environment were the same as those in preparation example 7.

Preparation example 10

The difference from preparation 9 is that: 2.5kg of the crosslinking treatment liquid and 1kg of the reinforcing agent 6 were mixed under stirring to prepare a crosslinked modified reinforcing agent 10, and the other preparation conditions and the preparation environment were the same as those in preparation example 7.

Preparation example 11

The difference from preparation 9 is that: 3kg of the crosslinking treatment solution and 1kg of the reinforcing agent 1 were mixed under stirring to obtain a crosslinked modified reinforcing agent 11, and the other preparation conditions and preparation environments were the same as those in preparation example 7.

Preparation example of blowing agent

Preparation examples 12 to 14

Respectively weighing sodium dodecyl sulfate and cocamidopropyl betaine, wherein the specific mass is shown in table 2; mixing sodium dodecyl sulfate and cocamidopropyl betaine under stirring to obtain foaming agent 1-3.

TABLE 3 blowing agent Components in preparation examples 12 to 14

Examples of preparation of stabilizers

Preparation examples 15 to 17

Respectively weighing hydroxypropyl methylcellulose and sodium carboxymethylcellulose, wherein the specific mass is shown in table 3; mixing hydroxypropyl methylcellulose and sodium carboxymethylcellulose under stirring to obtain stabilizer 1-3

TABLE 4 stabiliser Components from preparation examples 15 to 17

Examples

Examples 1 to 4

Aggregate, cement, a reinforcing agent 1, a water reducing agent, a foaming agent 1 and water are respectively weighed, and the specific mass is shown in table 4.

Firstly, putting a foaming agent and 20% of water by mass into a high-speed stirrer, stirring and mixing, and continuously stirring for 5min to prepare foam; placing aggregate, cement and a reinforcing agent into a planetary mixer, stirring and mixing, adding 80% by mass of water and all water reducing agents into the mixer, continuously stirring to prepare uniformly mixed slurry, adding foam into the slurry until the slurry is uniformly mixed to prepare concrete 1-4, laying the concrete on a template, uniformly vibrating, curing for 28 days, standing and curing.

Table 5 concrete compositions of examples 1-4

Examples 5 to 14

The difference from example 3 is that: concrete 5 to 14 was prepared using reinforcing agents 2 to 11 in place of reinforcing agent 1 in example 3, and the other preparation conditions and preparation environments were the same as in example 3.

Examples 15 to 16

The difference from example 13 is that: concrete 15 to 16 was prepared by using the foaming agents 2 to 3 in place of the foaming agent 1 in example 12, and the other preparation conditions and preparation environments were the same as those in example 12.

Examples 17 to 19

The difference from example 15 is that: the foaming agent is a foaming agent subjected to stabilizing treatment, and the stabilizing treatment comprises the following steps:

respectively weighing nano silicon dioxide, a sodium hydroxide solution with the mass fraction of 10%, a stabilizer 1 and a foaming agent 2, wherein the specific mass is shown in Table 6;

stirring and mixing nano silicon dioxide and a sodium hydroxide solution, placing the mixture in an ultrasonic machine, carrying out ultrasonic treatment for 15min to prepare a dispersion solution, stirring and mixing the dispersion solution and a foaming agent, stirring the mixture at a constant temperature of 20 ℃ for 3h to prepare a mixed solution, controlling the pH =10.5 of the mixed solution, adding a stabilizer 1 into the mixed solution, continuing stirring and mixing the mixture for 3h to prepare a foaming agent 4-6 subjected to stabilization treatment, and preparing concrete 17-19, wherein the rest preparation conditions and preparation environment are the same as those in example 15.

TABLE 6 examples 17-19 stabilize blowing agent compositions

Examples 20 to 21

The difference from example 18 is that: concrete 20 to 21 was prepared using the stabilizers 2 to 3 in place of the stabilizer 1 in example 18, and the other preparation conditions and preparation environment were the same as in example 18.

Performance test

Preparing the anti-crack concrete sample according to the Standard Specification of the test method for the mechanical properties of GB/T50081-2002 common concrete.

(1) And (3) detecting the compression resistance: placing the sample under a press, uniformly and continuously applying a load to the sample, controlling the loading speed to be 0.08MPa/s until the sample is damaged, and recording the strength of the load;

(2) and (3) detecting the breaking strength: detecting a concrete sample by adopting an anti-bending machine, placing the sample on the anti-bending machine, taking the sample at a position 50mm away from two end faces as a support point of the sample, taking three point positions of the sample as loading points, uniformly and continuously applying load to the sample, controlling the loading speed to be 0.08MPa/s until the sample is damaged, and recording the load strength;

(3) and (3) detecting the water permeability: according to CJJ/T135-one 2009 permeable cement concrete pavement technical specification, a specified water head method is adopted to measure the water permeability coefficient, a formed sample with the thickness of 150mm multiplied by 150mm is coated with two layers of PE films, the sample block is placed into a water permeability instrument, rubber cement is used for sealing the joint, water is poured to the top of the instrument, the water permeability time is recorded by a stopwatch, T/s is measured, and the water permeability coefficient can be calculated.

Table 7 examples 1-21 performance testing

Comparative example

Comparative example 1

The difference from example 20 is that: concrete 22 was prepared using polypropylene fibers in place of the reinforcing agent 12, and the other preparation conditions and preparation environments were the same as in example 20.

Comparative example 2

The difference from example 20 is that: only the reinforcing agent was crosslinked to prepare a modified reinforcing agent 15, and concrete 23 was prepared in place of the reinforcing agent 12 under the same preparation conditions and preparation environment as in example 20.

Comparative example 3

The difference from example 20 is that: concrete 24 was prepared using dodecanol in place of the foaming agent 2, and the remaining preparation conditions and preparation environment were the same as in example 20.

Comparative example 4

The difference from example 20 is that: concrete 25 was prepared without adding a stabilizer, and the other preparation conditions and preparation environments were the same as in example 20.

Performance test

TABLE 8 comparative examples 1-4 Performance test

Comparing the performance tests in table 7 and table 8, it can be found that:

(1) a comparison of examples 1-3, 4, 5-6 and comparative example 1 shows that: the compressive strength and the water permeability coefficient of the concrete prepared in the examples 1 to 3 and the examples 5 to 6 are improved, which shows that the fly ash and the needle-shaped wollastonite are compounded to be used as the reinforcing agent, and the fly ash can be loaded on the needle-shaped wollastonite, so that the dispersing effect of the needle-shaped wollastonite in the concrete is better, the dispersing effect of the reinforcing agent in the concrete is improved, and the reinforcing agent is used for uniformly connecting the concrete base material. Meanwhile, the fly ash has more pores, so that the pores are increased for the concrete, the water permeability effect of the concrete is further improved, the strength of the concrete is improved, and the water permeability effect of the concrete is also improved.

As can be seen from tables 7 and 8, the concrete obtained in example 3 and example 5 has better compressive strength and water permeability, which indicates that the concrete in example 3 has a suitable ratio of each component and the concrete in example 5 has a suitable ratio of the reinforcing agent component.

(2) A comparison of examples 7 to 9 with examples 10 to 11 shows that: the compressive strength and the water permeability coefficient of the concrete prepared in the examples 7 to 9 and 10 to 11 are improved, which shows that the reinforcing agent is reinforced, the reinforcing agent is coated with silica sol, and after the roasting treatment, the reinforcing agent is coated with hydrophilic silica, so that the hardness and the strength of the reinforcing agent are improved, and the reinforcing agent stably enhances the strength of the concrete. Secondly, the stability of the pores of the reinforcing agent is guaranteed, and the water permeability effect of the concrete is stably improved. Finally, the dispersing effect of the reinforcing agent in the concrete is improved, so that the concrete obtains more uniform and stable strength. As can be seen from Table 7, the concrete produced in example 9 and example 10 is excellent in compressive strength and water permeability, and it is demonstrated that the composition ratio of the total raw materials for the strengthening treatment in example 9 is suitable, and the gelling temperature and the baking treatment temperature in example 10 are suitable.

(3) A comparison of examples 12 to 14 with comparative example 2 shows that: the concrete prepared in the embodiments 12 to 14 has improved compressive strength and water permeability coefficient, which shows that the reinforcing agent is cross-linked, and the redispersible latex powder has better dispersibility in water, so that the redispersible latex powder can be uniformly coated outside the reinforcing agent, thereby improving the bonding effect between the reinforcing agent and the base material, and stably improving the strength of the concrete. As is apparent from tables 7 and 8, the concrete obtained in example 13 is the most excellent in compressive strength and water permeability, and the ratio between the crosslinking treatment liquid and the reinforcing agent is appropriate at this time.

(4) A comparison of examples 15 to 16 with comparative example 3 shows that: the compressive strength and the water permeability coefficient of the concrete prepared in the embodiments 15 to 16 are improved, which shows that the foaming effect of the foaming agent is improved by compounding the anionic surfactant and the amphoteric surfactant serving as the foaming agent, and the obtained foam is relatively stable, and the foam is mixed with the concrete to stably provide pores for the concrete, so that the concrete obtains relatively uniform and stable pores, and the strength and the water permeability of the concrete are improved. As can be seen from tables 7 and 8, the concrete obtained in example 15 is excellent in compressive strength and water permeability, and the component ratio of the foaming agent in example 15 is appropriate.

(5) A comparison with examples 17 to 19 shows that: the compressive strength and the water permeability coefficient of the concrete prepared in the embodiments 17 to 19 are improved, which shows that the foaming agent is stabilized, and the nano-silica is added into the foaming agent, so that the nano-silica generates active oxygen ions under the initiation of sodium hydroxide, and further the nano-silica and the foaming agent can be crosslinked, and when the foaming agent generates foam, the nano-silica is stably coated outside the foam, so that the stability of the foam is improved, and the concrete obtains stable porosity. Meanwhile, after the concrete is cured, the nano silicon dioxide is stably loaded on the inner wall of the pore of the concrete, so that the strength of the pore of the concrete is guaranteed, namely, the strength of the concrete is improved, and the concrete not only obtains a better water permeating effect, but also obtains more uniform strength.

As can be seen from Table 7, the concrete obtained in example 18 is the most excellent in compressive strength and water permeability, and the proportions of the respective components in the stabilization modification in example 18 are appropriate.

(6) A comparison of examples 20 to 21 with comparative example 4 shows that: the compressive strength and water permeability coefficient of the concrete prepared in examples 20-21 are improved, which indicates that the cellulose ether is used as a stabilizer, the cellulose ether absorbs and stores water during the concrete mixing process, and slowly releases water during the concrete curing process, so that the concrete is internally cured, and the strength of the concrete is further improved. By compounding the ionic cellulose ether and the nonionic cellulose ether, the viscosity of the foaming agent is improved, the stability of foam formed by the foaming agent is improved, the foam is stable, pores are provided for concrete, and the water permeation effect of the concrete is guaranteed. In addition, the dispersion effect in the foam and the concrete is improved, so that the concrete obtains more uniform porosity, namely the concrete obtains more uniform strength.

As can be seen from tables 7 and 8, the concrete obtained in example 20 has the best compressive strength and water permeability, which indicates that the ratio of the components in the stabilizer is suitable.

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 sponge urban pervious concrete is characterized by comprising the following substances in parts by weight: 30-50 parts of aggregate, 20-30 parts of cement, 3-5 parts of reinforcing agent, 1-2 parts of water reducing agent, 2-3 parts of foaming agent and 10-20 parts of water, wherein the reinforcing agent comprises fly ash and wollastonite, the mass ratio of the fly ash to the wollastonite is 1:0.5-2, and the wollastonite is needle-shaped wollastonite.

2. The sponge urban pervious concrete according to claim 1, wherein the reinforcing agent is a modified reinforcing agent, the modification treatment comprises a cross-linking treatment, and the cross-linking treatment comprises the following steps: taking redispersible latex powder and water, stirring and mixing to obtain a crosslinking treatment solution, and mixing the crosslinking treatment solution and a reinforcing agent according to a mass ratio of 2-3: 1 stirring and mixing to obtain the reinforcing agent after crosslinking treatment.

3. The sponge urban pervious concrete of claim 2, wherein the modification treatment further comprises a strengthening treatment, the strengthening treatment further comprising the steps of:

(1) acid washing: according to the mass ratio of 5-8: 1, taking hydrochloric acid and a reinforcing agent, stirring and mixing, heating, continuously reacting for 2-4 hours, filtering, retaining a filter cake, washing the filter cake until a washing liquid is neutral, and drying the filter cake at 35 ℃ to prepare the acid-washed reinforcing agent;

(2) coating: according to the mass ratio of 2-3: 1, taking silica sol and the reinforcing agent pickled in the step (1), stirring and mixing to prepare a mixed solution, adding ammonia water into the mixed solution, continuously stirring, controlling the gelling temperature to prepare a gel solution, drying the gel solution at 40-60 ℃ in vacuum to prepare a dried product, and roasting to prepare the reinforcing agent subjected to strengthening treatment.

4. The sponge urban pervious concrete according to claim 3, characterized in that: the gelling temperature in the step (2) is 20-50 ℃, the roasting treatment temperature is 800-1200 ℃, and the roasting treatment time is 1-3 h.

5. The sponge urban pervious concrete according to claim 1, characterized in that: the foaming agent comprises sodium dodecyl sulfate and cocamidopropyl betaine, and the mass ratio of the sodium dodecyl sulfate to the cocamidopropyl betaine is 1: 2-5.

6. The sponge urban pervious concrete according to claim 5, characterized in that: the foaming agent is a foaming agent subjected to stabilizing treatment, and the stabilizing treatment comprises the following steps:

(1) respectively weighing the following substances in parts by weight: 3-5 parts of nano silicon dioxide, 10-15 parts of sodium hydroxide solution, 1-2 parts of stabilizer and 4-8 parts of foaming agent;

(2) and (3) stable modification: taking nano silicon dioxide and sodium hydroxide solution according to a formula, stirring and mixing, carrying out ultrasonic treatment for 15-30min to prepare dispersion liquid, adding a foaming agent into the dispersion liquid, controlling the pH =10-11, stirring at a constant temperature of 15-30 ℃, carrying out 2-4h to prepare mixed solution, adding a stabilizing agent into the mixed solution, and continuously stirring and mixing to prepare the foaming agent subjected to stabilizing treatment.

7. The sponge urban pervious concrete according to claim 6, wherein: the stabilizer comprises one or two of hydroxypropyl methylcellulose and sodium carboxymethyl cellulose.

8. The construction process of the sponge city pervious concrete as claimed in any one of claims 1 to 7, characterized by comprising the following steps:

s1, pre-foaming: taking a foaming agent and water according to the formula, stirring and mixing for 3-5min to prepare foam;

s2, concrete preparation: mixing cement, aggregate and a reinforcing agent by stirring to obtain a mixture, adding a water reducing agent and water into the mixture, continuously stirring and mixing to obtain mixed slurry, and stirring and mixing the foam obtained in the step S1 with the mixed slurry to obtain concrete;

s3, paving: and uniformly paving the concrete on the template, uniformly vibrating, standing and curing.