CN116120017A

CN116120017A - Preparation process of renewable lightweight concrete

Info

Publication number: CN116120017A
Application number: CN202310159518.9A
Authority: CN
Inventors: 贾向锋; 王茂才; 陈光明
Original assignee: Yangzhou Huayun New Material Technology Co ltd
Current assignee: Yangzhou Huayun New Material Technology Co ltd
Priority date: 2023-02-24
Filing date: 2023-02-24
Publication date: 2023-05-16

Abstract

The application discloses a renewable lightweight concrete preparation process, wherein the lightweight concrete comprises the following raw materials in parts by weight: 100-180 parts of water, 80-150 parts of Portland cement, 100-150 parts of recycled aggregate, 60-100 parts of expanded polystyrene powder, 2050 parts of glass powder, 60-100 parts of quartz sand, 10-40 parts of silica fume, 10-20 parts of water reducer and 10-20 parts of air entraining agent; and the whole process of mixing, blank making and autoclaved aerated curing treatment is adopted. The preparation method has the advantages of low process difficulty, easily obtained raw materials of each component, low cost and high strength, and the prepared concrete is light.

Description

Preparation process of renewable lightweight concrete

Technical Field

The application relates to the technical field of concrete preparation, in particular to a preparation process of renewable light concrete.

Background

As the urban residential housing is updated and the municipal construction engineering amount is continuously increased, a large number of old buildings are destroyed, and the urban construction waste amount is increased. The construction waste is simply used as backfill material or is transported to a garbage yard for piling up, so that not only is a great deal of resource waste caused, but also the construction waste occupies land, and serious environmental pollution is caused.

In recent years, attention has been paid to the disposal of such construction wastes, and accordingly, the recycling of such construction wastes, the pulverization of the construction wastes, and the production and preparation of recycled construction materials are now newer disposal methods for such construction wastes. Correspondingly, techniques for preparing building concrete using these recycled materials have been developed, and the concrete prepared using these recycled building materials is recycled concrete.

The recycled concrete has the technical effects of low density, heat insulation, sound insulation and the like. This is because recycled aggregate has a lower apparent density than natural aggregate, and thus recycled concrete has a lower density than ordinary concrete. The density of the recycled concrete is regularly reduced along with the increase of the mixing amount of the recycled aggregate, and the recycled concrete density of the recycled aggregate is lower than that of the common concrete, because the recycled aggregate has high porosity and low density, which is beneficial to reducing the dead weight of the structural member. And because of the large porosity, the composite material also has the advantages of silencing and heat preservation.

However, the existing recycled concrete has the problem of insufficient strength. Since the various properties of recycled aggregate are obviously inferior to those of natural aggregate used in ordinary concrete, the strength of recycled concrete is obviously lower than that of the existing ordinary concrete. This also results in limited use of recycled concrete and difficulty in wide application.

Disclosure of Invention

In order to solve at least one technical problem, the preparation process of the renewable light concrete is developed, wherein the process difficulty is low, raw materials of all components are easy to obtain, the cost is low, and meanwhile, the prepared renewable concrete is light and high in strength.

The application provides a renewable lightweight concrete preparation process, wherein the lightweight concrete comprises the following raw materials in parts by weight: 100-180 parts of water, 80-150 parts of Portland cement, 100-150 parts of recycled aggregate, 60-100 parts of expanded polystyrene powder, 2050 parts of glass powder, 60-100 parts of quartz sand, 10-40 parts of silica fume, 10-20 parts of water reducer and 10-20 parts of air entraining agent;

the preparation process comprises the following steps:

s1, uniformly mixing and stirring glass powder, silica fume and expanded polystyrene powder in a formula amount, portland cement in a formula amount of 1/3-1/2 and water in a formula amount of 1/2-2/3 to prepare slurry;

s2, uniformly mixing the recycled aggregate with the formula amount and the quartz sand, adding the rest water with the formula amount, uniformly mixing and stirring to prepare mixed aggregate;

s3, adding the mixed aggregate prepared in the step S2 into the slurry prepared in the step S1, sequentially adding the silicate cement with the residual formula amount, the water reducing agent and the air entraining agent into the slurry, and uniformly mixing and stirring to prepare a mixture;

s4, pouring the mixture prepared in the step S3 into a mould, and then standing for pre-solidifying to prepare a concrete blank;

and S5, transferring the concrete blank prepared in the step S4 into an autoclave, and performing steam pressurizing curing treatment to prepare a concrete finished product.

By adopting the technical scheme, the recycled aggregate, glass powder and quartz sand are adopted as the aggregate through the specific concrete proportion, and the artificial aggregate and the building recycled material are added with the expanded polystyrene powder and the silica fume, so that the prepared concrete is light in weight and high in strength; the method adopts the autoclaved process, and the micro silicon powder and the air entraining agent are matched for use, so that the curing is completed during the autoclaved process, the process is simple, the complex curing process is avoided, the prepared concrete is stable in quality, light in weight and good in heat insulation and sound insulation effects.

Optionally, in the step S1, the grain size of the silica fume is controlled to be 200-500 μm.

Optionally, in the step S1, the particle size of the glass powder is controlled to be 4-10 mm.

Optionally, in the step S2, the particle size of the recycled aggregate is controlled to be 20-40 mm.

Optionally, in the step S2, the particle size of the quartz sand is controlled to be 2-6 mm.

Optionally, in the step S3, the water reducer is a naphthalene water reducer.

Optionally, in the step S3, the air entraining agent is aluminum powder.

Optionally, in the step S4, the standing pre-coagulation is performed at normal temperature, and the time of the standing pre-coagulation is controlled to be 120-180 min.

Optionally, in the step S5, the steam pressurizing maintenance treatment is to boost the pressure in the autoclave to 1.5-1.55 MPa, then keep the temperature and pressure for 350-400 min, and finally naturally release the pressure.

Further optionally, in the step S5, the temperature in the autoclave is raised to 45-55 ℃ before the pressure is raised, and the autoclave is kept at a constant temperature for 20-30 min.

In summary, the present invention includes at least one of the following beneficial technical effects:

1. the method adopts a large amount of artificial aggregate and building reclaimed materials as aggregate, does not add any natural aggregate, and effectively avoids environmental pollution.

2. According to the method, after mixing, the autoclaved aerated process is adopted to prepare concrete, light glass powder and quartz sand are used as fine aggregate, and expanded polystyrene powder is added at the same time, so that the prepared concrete is light in texture.

3. The silica fume is added, the silicate cement and the air entraining agent are matched, the autoclaved air entraining process is adopted to prepare concrete, the grading of each aggregate is good, and the prepared concrete has good strength.

4. The raw materials of the method are easy to obtain, the cost is low, the preparation process is simple, the process of the method can be realized by using stirring equipment and an autoclave, the equipment cost is low, the overall cost is low, the application prospect is good, and certain economic and social benefits are achieved.

Detailed Description

The present application is described in further detail below with reference to examples.

The application designs a preparation process of renewable lightweight concrete.

The renewable lightweight concrete disclosed by the application adopts the following raw material formula in parts by weight: comprises 100 to 180 parts of water, 80 to 150 parts of silicate cement, 100 to 150 parts of recycled aggregate, 60 to 100 parts of expanded polystyrene powder, 2050 parts of glass powder, 60 to 100 parts of quartz sand, 10 to 40 parts of silica fume, 10 to 20 parts of water reducer and 10 to 20 parts of air entraining agent.

The preparation process specifically comprises the following steps:

Prior to this application, the art of recycled concrete was prepared with very few autoclaved air-entraining processes. Autoclaved aerated concrete has a light texture, but the concrete contains abundant pores, so the strength is not high. Meanwhile, the strength of the recycled concrete is generally lower than that of the recycled concrete adopting natural aggregate due to the adoption of a large amount of recycled aggregate, and the recycled concrete is generally not prepared by adopting an autoclaved air-entraining process in order to ensure the strength of the concrete based on the factor. Even if the autoclaved aerated process is adopted to prepare the recycled concrete, the recycled concrete is also generally used for filling non-bearing buildings, and the strength of the recycled concrete is difficult to meet the requirement of bearing the building.

The applicant has devised the present application through the study of the grading of the recycled aggregate of the concrete and the study of the improvement of the performance of the aerated concrete. The regenerated light concrete with high strength is prepared by adopting a specific proportion and an autoclaved air-entraining process.

The following is a preparation example of the present application.

Preparation example 1

The preparation process of the renewable lightweight concrete comprises the following steps:

s1, preparing slurry: mixing and stirring glass powder, silica fume and expanded polystyrene powder in the formula amount, portland cement in the formula amount of 1/3 and water in the formula amount of 1/2 uniformly to prepare slurry;

s2, preparing mixed aggregate: uniformly mixing the recycled aggregate with the quartz sand in the formula amount, adding the rest water in the formula amount, uniformly mixing and stirring to prepare mixed aggregate;

s3, mixing: adding the mixed aggregate prepared in the step S2 into the slurry prepared in the step S1, and then sequentially adding the silicate cement with the residual formula amount, the water reducer with the formula amount and the air entraining agent into the slurry, and uniformly mixing and stirring to prepare a mixture;

s4, blank making: pouring the mixture prepared in the step S3 into a mould, standing at normal temperature, pre-solidifying for 45min, and removing the mould to prepare a concrete blank;

s5, preparing a concrete finished product: and (3) transferring the concrete blank prepared in the step (S4) into an autoclave, performing steam pressurizing curing treatment, and finally preparing a concrete finished product by adopting common autoclaved aerated curing technological parameters.

The recycled aggregate of the preparation example adopts concrete block fragments. The common autoclaved aerated curing process parameters of the preparation example are as follows: the pressure in the autoclave is increased to 1.1-1.2 MPa, then the autoclave is kept warm and pressure is maintained for about 5 hours, and finally the pressure is naturally released.

Preparation example 2

The difference between this preparation and preparation 1 is:

in the step S1 of the preparation example, the micro silicon powder is micron-sized powder with the grain diameter controlled between 200 and 500 mu m.

Preparation example 3

The difference between this preparation and preparation 2 is:

in step S1 of the present preparation example, the glass frit is waste architectural glass, and is crushed to a particle size of 4 to 10mm.

Preparation example 4

The difference between this preparation and preparation 3 is:

in the step S2 of the preparation example, the recycled aggregate adopts waste building stones and is crushed into stones with the particle size of 20-40 mm; the quartz sand adopts powder with the particle size controlled between 2 and 6mm.

Preparation example 5

The difference between this preparation and preparation 4 is:

in the step S3 of the preparation example, the water reducer is a naphthalene water reducer with a kaleidoscope brand.

Preparation example 6

The difference between this preparation and preparation 5 is:

in the step S4 of the present preparation example, the standing pre-coagulation is performed at normal temperature, and the time of the standing pre-coagulation is controlled to be 2 hours.

Preparation example 7

The difference between this preparation and preparation 5 is:

in the step S4 of the present preparation example, the standing pre-coagulation is performed at normal temperature, and the time of the standing pre-coagulation is controlled to be 3 hours.

Preparation example 8

The difference between this preparation and preparation 5 is:

in the step S4 of the present preparation example, the standing pre-coagulation is performed at normal temperature, and the time of the standing pre-coagulation is controlled to be 2.5 hours.

Preparation example 9

The difference between this preparation and preparation 6 is:

in the step S5 of the preparation example, the steam pressurizing maintenance treatment is to firstly boost the pressure in the autoclave to 1.5-1.55 MPa, then keep the temperature and pressure for 350min and finally naturally release the pressure.

Preparation example 10

The difference between this preparation and preparation 6 is:

in the step S5 of the preparation example, the steam pressurizing maintenance treatment is to firstly boost the pressure in the autoclave to 1.5-1.55 MPa, then keep the temperature and pressure for 400min and finally naturally release the pressure.

PREPARATION EXAMPLE 11

The difference between this preparation and preparation 9 is:

in the step S5 of the preparation example, the temperature in the autoclave is raised to 45-55 ℃ before the pressure is increased, and the autoclave is kept at a constant temperature for 20min.

Preparation example 12

The difference between this preparation and preparation 9 is:

in the step S5 of the preparation example, the temperature in the autoclave is raised to 45-55 ℃ before the pressure is increased, and the autoclave is kept at a constant temperature for 30min.

Preparation example 13

The difference between this preparation and preparation 5 is:

the preparation method does not add air entraining agent, does not adopt autoclaved air entraining maintenance, and adopts ordinary normal maintenance instead.

PREPARATION EXAMPLE 14

The difference between this preparation and preparation 12 is:

in step S1 of this preparation example, portland cement in an amount of 1/2 of the formulation and water in an amount of 2/3 of the formulation were added.

The following are examples 1-12 of the present application, and the specific proportions and preparation modes are shown in tables 1 and 2.

Table 1 examples 1 to 12 main raw material ratio table

Table 2 examples 1 to 12 ingredients ratios and preparation modes are shown in table

And (3) detection and verification:

the third example of the Chinese patent with publication No. CN113955989A is given as a comparative example.

The concretes of examples 1 to 14 of the present application were prepared to 1m ³ The weight and compressive strength were then measured, and the results are shown in Table 3.

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

Quality of

771kg

765kg

762kg

763kg

761kg

747kg

751kg

Strength of

4.4Mpa

4.6Mpa

4.7Mpa

5.2Mpa

5.3Mpa

5.6Mpa

6.4Mpa

Example 8

Example 9

Example 10

Example 11

Example 12

Example 13

Example 14

Quality of

753kg

758kg

745kg

743kg

786kg

823kg

839kg

Strength of

7.1Mpa

7.2Mpa

7.5Mpa

7.6Mpa

2.7Mpa

4.3Mpa

3.9Mpa

Whereas the concrete of the comparative example was prepared to 1m ³ The weight and compressive strength were then examined, the mass thereof was 783kg, and the strength was 4.2MPa.

As can be seen from the data in table 3 and the test of the comparative examples, the quality and strength of the concrete in examples 1 to 11 are better than those of the comparative examples, and it can be seen that the autoclaved aerated curing is adopted in the concrete preparation method, and the grading of the concrete is better after the proper formulation is adopted; meanwhile, after the micro silicon powder is added, special crosslinking is generated inside, so that the texture is light, and meanwhile, the strength is effectively improved.

It can also be seen from the data of Table 3 that the quality and strength of the concretes of examples 12-14 of the present application are significantly poorer than those of examples 1-11; and the quality and strength of the concrete of example 12 of the present application is the worst relative to other examples. From this, it can be seen that the strength of concrete prepared by the method is obviously insufficient without adopting an autoclaved air-entraining process; meanwhile, even if the process is adopted, the strength of the concrete is insufficient without adopting the specific proportion.

It can also be seen from the data in table 3 that the quality and strength properties of the concretes of examples 7 to 11 of the present application are significantly better than those of examples 1 to 6, and that the strength properties of the concretes of examples 1 to 4 of the present application are in a tendency to be improved. Therefore, the special autoclaved aerated curing process is adopted, so that the strength of the concrete can be effectively improved, and after the special aggregate particle size is adopted, the grading is obviously improved, and the strength of the concrete can also be effectively improved.

It can also be seen from the data of table 3 that the quality and strength properties of the concretes of examples 10 and 11 of the present application are significantly optimal. From the above, the optimized raw material proportion is adopted, namely 145-165 parts of water, 135-145 parts of silicate cement, 145-150 parts of recycled aggregate, 70-75 parts of expanded polystyrene powder, 4045 parts of glass powder, 70-75 parts of quartz sand, 32-36 parts of silica fume, 16-18 parts of water reducer and 16-18 parts of air entraining agent; and the prepared concrete has the best strength by adopting the specific aggregate particle size and the specific autoclaved aerated curing process.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims

1. The preparation process of the renewable light concrete is characterized in that the light concrete comprises the following raw materials in parts by weight: 100-180 parts of water, 80-150 parts of Portland cement, 100-150 parts of recycled aggregate, 60-100 parts of expanded polystyrene powder, 2050 parts of glass powder, 60-100 parts of quartz sand, 10-40 parts of silica fume, 10-20 parts of water reducer and 10-20 parts of air entraining agent;

the preparation process comprises the following steps:

2. The process for preparing renewable lightweight concrete according to claim 1, wherein in the step S1, the grain size of the silica fume is controlled to be 200-500 μm.

3. The process for preparing renewable lightweight concrete according to claim 1, wherein in the step S1, the particle size of the glass powder is controlled to be 4-10 mm.

4. The process for preparing renewable lightweight concrete according to claim 1, wherein in the step S2, the particle size of the recycled aggregate is controlled to be 20-40 mm.

5. The process for preparing renewable lightweight concrete according to claim 1, wherein in the step S2, the particle size of the quartz sand is controlled to be 2-6 mm.

6. The process for preparing renewable lightweight concrete according to claim 1, wherein in step S3, the water reducer is naphthalene water reducer.

7. The process for preparing renewable lightweight concrete according to claim 1, wherein in step S3, the air entraining agent is aluminum powder.

8. The process for preparing renewable lightweight concrete according to claim 1, wherein in the step S4, the standing pre-setting is performed at normal temperature, and the time of the standing pre-setting is controlled to be 120-180 min.

9. The process for preparing renewable lightweight concrete according to claim 1, wherein in the step S5, the steam pressurizing curing treatment is performed by first pressurizing the inside of the autoclave to 1.5-1.55 mpa, then preserving heat and pressure for 350-400 min, and finally naturally releasing pressure.

10. The process for preparing renewable lightweight concrete according to claim 9, wherein in step S5, the temperature in the autoclave is raised to 45-55 ℃ before the pressure is raised, and the autoclave is kept at rest for 20-30 min.