CN109627039B - Autoclaved aerated concrete block and preparation method and application thereof - Google Patents

Abstract

The invention relates to an autoclaved aerated concrete block and a preparation method and application thereof, wherein the autoclaved aerated concrete block is prepared by mixing a solid dry material, a foaming agent and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20 to 40 percent of dry building mud/building mud cake, 23 to 46 percent of yellow sand, 15 to 25 percent of quicklime, 10 to 20 percent of cement and 0.5 to 1.5 percent of desulfurized gypsum; the foaming agent accounts for 0.07-0.10% of the total mass of the solid dry material; the water accounts for 65-75% of the total mass of the solid dry materials. According to the autoclaved aerated concrete block and the preparation method thereof, the solid dry material, the foaming agent and the water in a specific ratio are compounded, so that the product performance can integrally reach the national standard, the autoclaved aerated concrete block can be widely applied as a novel energy-saving wall material, and the production period is short.

Description

Autoclaved aerated concrete block and preparation method and application thereof

Technical Field

The invention relates to the field of building materials, in particular to an autoclaved aerated concrete block and a preparation method and application thereof.

Background

Along with the rapid development of urban municipal construction, a large amount of building slurry is generated while beautifying the environment, and because the slurry has high water content and large volume, if the slurry is directly treated in a landfill mode, the slurry not only occupies a large-volume landfill, but also has the environmental risk of secondary pollution.

At present, a plurality of construction slurry curing treatment centers in the market adopt a dehydration and consolidation integrated treatment technology, so that the reduction of construction slurry is effectively realized, but mud cakes generated after dehydration and consolidation are generally used as solid wastes and directly entrusted to a slag team for external transportation and landfill treatment. The treatment mode not only causes the waste of resources, but also destroys the ecological environment. The construction slurry/dewatered mud cake is recycled, and the method has very important significance for reducing land occupation.

The autoclaved aerated concrete block is a novel building wall material which is light and has closed micropores and is prepared by taking fly ash, cement, lime, gypsum and the like as main raw materials, adding a proper amount of gas former, pouring, standing still, cutting, forming and high-temperature steam curing. The autoclaved aerated concrete block has the advantages of light volume weight, heat preservation, heat insulation, water resistance, sound absorption, good earthquake resistance, convenient site construction and the like, is mainly suitable for filling walls, non-bearing partition walls, composite heat preservation layers of peripheral retaining walls of energy-saving buildings, self-heat preservation outer walls, roofing heat preservation layers and the like of frames and high-rise buildings, and is a novel energy-saving wall material widely applied at home and abroad.

Although the Chinese invention patent with the application number of 201310363431.X discloses a non-autoclaved aerated concrete block made of building slurry and a manufacturing method thereof, the strength and dry density performance indexes of the concrete block obtained in the patent document can not reach the national standard. In addition, the method disclosed in the patent document adopts stacking maintenance for 28 days, and the production period is long. Therefore, how to prepare the autoclaved aerated concrete block with the performance meeting the national standard by adopting the building slurry/building mud cake and develop a production process with short production period is a subject to be solved urgently.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides an autoclaved aerated concrete block with strength and dry density performance indexes reaching the national standard and a preparation method thereof.

The technical scheme for solving the technical problems is as follows:

the autoclaved aerated concrete block is prepared by mixing a solid dry material, a foaming agent and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20 to 40 percent of dry building mud/building mud cake, 23 to 46 percent of yellow sand, 15 to 25 percent of quicklime, 10 to 20 percent of cement and 0.5 to 1.5 percent of desulfurized gypsum; the foaming agent accounts for 0.07-0.10% of the total mass of the solid dry material; the water accounts for 65-75% of the total mass of the solid dry materials.

In one embodiment, the solid dry material is composed of the following raw materials in percentage by mass: 20% of dry building mud/building mud cake, 46% of yellow sand, 15% of quicklime, 18% of cement and 1% of desulfurized gypsum; the foaming agent accounts for 0.070-0.077% of the total mass of the solid dry material; the water accounts for 70% of the total mass of the solid dry material.

In one embodiment, the foaming agent is aluminum paste.

In one embodiment, the dry construction mud/construction mud cake has a silica content of no less than 45%.

In one embodiment, the building mud is mud generated in the processes of drilling pile foundation construction, underground continuous wall construction, slurry shield construction and trenchless construction; the building mud cake is a material obtained by dewatering and consolidating the building mud.

A preparation method of any one of the autoclaved aerated concrete blocks comprises the following steps:

drying the building slurry/building mud cake, calculating the water content of the building slurry/building mud cake, and deducting the water content in the building slurry/building mud cake when weighing water;

weighing the raw materials according to the composition of any one of the autoclaved aerated concrete blocks;

adding water into the building mud/building mud cake, stirring and uniformly mixing; then adding the yellow sand and the desulfurized gypsum, and stirring and mixing uniformly; adding cement, and stirring and mixing uniformly; adding quicklime, adding a foaming agent under the stirring condition, uniformly stirring and mixing, and controlling the pouring temperature to be 40-50 ℃ to obtain a mixed material;

injecting the mixed material into a mold for gas generation and standing for pre-curing to obtain a blank body;

and (4) moving the blank into a still kettle for steam pressure maintenance to obtain the product.

In one embodiment, the step of weighing the yellow sand further comprises the step of grinding the yellow sand to a screen residue of not more than 10% on a 0.075mm mesh screen.

In one embodiment, the gas generation and standing pre-culture comprises the following steps: fixing a bottom plate of the mold by using bolts, coating an oil layer on the inner film, pouring the mixed material, covering the surface of the mold by using a film, allowing the gas to flow for 30-50min, and standing and maintaining for 3-4 h.

In one embodiment, the autoclave curing process parameters are as follows: the temperature is 180 ℃ to 190 ℃, the vacuum pumping is carried out for 0.5h until the pressure reaches-0.06 MPa, the pressure is increased for 2.5h until the pressure reaches 1.0-1.5MPa, the pressure is maintained for 8h, and the pressure is reduced for 1.5h until the normal pressure is reached.

The autoclaved aerated concrete block is applied to the manufacturing of a wall body.

The invention has the beneficial effects that:

(1) the autoclaved aerated concrete block can integrally achieve the performance of the product meeting the A3.5B06 grade requirement in the national standard GB11968-2006 autoclaved aerated concrete block by compounding the solid dry material, the foaming agent and the water according to a specific ratio, and can be widely applied as a novel energy-saving wall material.

(2) The autoclaved aerated concrete block utilizes the building slurry/building mud cakes as one of the raw materials, not only can reduce the production cost, but also can realize the resource utilization of solid wastes, and has considerable social benefit and economic benefit.

(3) The preparation method of the autoclaved aerated concrete block has the advantages of simple process and short production period, and can realize industrial production.

Detailed Description

The principles and features of this invention are described below in conjunction with examples which are set forth to illustrate, but are not to be construed to limit the scope of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The building slurry used in the invention is slurry generated in the processes of drilling pile foundation construction, underground continuous wall construction, slurry shield construction and trenchless construction; the building mud cake is a material obtained by dewatering and consolidating building mud.

Example 1

The embodiment provides an autoclaved aerated concrete block prepared from building slurry/building mud cakes, which is prepared by mixing a solid dry material, aluminum paste (foaming agent) and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20 percent of dry building mud/building mud cakes (the content of silicon dioxide is 50 percent), 46 percent of yellow sand, 15 percent of quicklime, 18 percent of cement and 1 percent of desulfurized gypsum. The aluminum powder paste accounts for 0.077 percent of the total mass of the solid dry materials. The water accounts for 70 percent of the total mass of the solid dry materials, namely the water-material ratio is 0.70. The water temperature was controlled at 40 ℃.

The preparation method of the autoclaved aerated concrete block comprises the following steps:

1) preparation of raw materials:

grinding the yellow sand until the residue of the yellow sand passing through a 0.075mm hole sieve is not more than 10%.

And drying the building mud/building mud cake, calculating the water content of the building mud/building mud cake, and deducting the water contained in the building mud/building mud cake when weighing water to obtain the dry building mud/building mud cake.

Weighing the following components in percentage by mass in the solid dry raw material: 20% of building slurry/mud cakes, 46% of yellow sand, 15% of quicklime, 18% of cement and 1% of desulfurized gypsum. The aluminum powder paste accounts for 0.077 percent of the total mass of the solid dry raw materials. The weighed mass of water is 70 percent of the total mass of the dry mixed materials, and the water temperature is controlled at 40 ℃.

2) Preparing a mixture:

firstly, adding water into the dry building mud/building mud cake, and uniformly stirring and mixing. Then adding the yellow sand and the desulfurized gypsum, and stirring and mixing uniformly. Then adding the cement, and stirring and mixing uniformly. And finally adding quicklime, continuously stirring for 2min, immediately adding the aluminum powder paste, stirring for 40s, ensuring that the mixture is uniformly mixed, and controlling the pouring temperature of the mixture to be 40-50 ℃ to obtain a mixed material.

3) Gas generation and standing pre-curing:

and pouring the stirred mixture into a sealed special mold which is approximately cubic, wherein the side length of the upper surface is 420mm, the side length of the lower surface is 440mm, and the height is 650 mm. The bottom plate of the mold is fixed by bolts, and the inner mold is coated with oil once, so that the demolding is facilitated. The surface of the mould is covered by a film to prevent water evaporation and heat loss. The gas forming process is controlled within 30-50min, and the height of the mixture is increased by nearly one time when the gas forming is finished. Standing and maintaining for 3-4 hours to obtain a blank with certain strength, and demolding and cutting.

4) Steam pressure curing:

transferring the green body into a still kettle for steam pressure curing, wherein a steam curing system is adopted: the temperature is 180-190 ℃, the mixture is vacuumized for 0.5h until the pressure reaches-0.06 MPa, the pressure is increased for 2.5h until the pressure is 1.0-1.5MPa, the pressure is maintained for 8h (1.0-1.5MPa), the pressure is reduced for 1.5h until the pressure is normal, and then the mixture is taken out of the kettle, thus obtaining the autoclaved aerated concrete block.

Example 2

The embodiment provides an autoclaved aerated concrete block prepared from building slurry/building mud cakes, which is prepared by mixing a solid dry material, aluminum paste (foaming agent) and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20 percent of dry building mud/building mud cakes (the content of silicon dioxide is 50 percent), 46 percent of yellow sand, 15 percent of quicklime, 18 percent of cement and 1 percent of desulfurized gypsum. The aluminum powder paste accounts for 0.070% of the total mass of the solid dry materials. The water accounts for 70 percent of the total mass of the solid dry materials, namely the water-material ratio is 0.70. The water temperature was controlled at 40 ℃.

The preparation method of the autoclaved aerated concrete block comprises the following steps:

1) preparation of raw materials:

grinding the yellow sand until the residue of the yellow sand passing through a 0.075mm hole sieve is not more than 10%.

And drying the building mud/building mud cake (the content of silicon dioxide is 50%), calculating the water content of the building mud/building mud cake, and deducting the water contained in the building mud/building mud cake when weighing water to obtain the dry building mud/building mud cake.

Weighing the following components in percentage by mass in the solid dry raw material: 20% of building slurry/mud cakes, 46% of yellow sand, 15% of quicklime, 18% of cement and 1% of desulfurized gypsum. The aluminum powder paste accounts for 0.070% of the total mass of the solid dry raw materials. The weighed mass of water is 70 percent of the total mass of the dry mixed materials, and the water temperature is controlled at 40 ℃.

2) Preparing a mixture:

firstly, adding water into the dry building mud/building mud cake, and uniformly stirring and mixing. Then adding the yellow sand and the desulfurized gypsum, and stirring and mixing uniformly. Then adding the cement, and stirring and mixing uniformly. And finally adding quicklime, continuously stirring for 2min, immediately adding the aluminum powder paste, stirring for 40s, ensuring that the mixture is uniformly mixed, and controlling the pouring temperature of the mixture to be 40-50 ℃ to obtain a mixed material.

3) Gas generation and standing pre-curing:

and pouring the stirred mixture into a sealed special mold which is approximately cubic, wherein the side length of the upper surface is 420mm, the side length of the lower surface is 440mm, and the height is 650 mm. The bottom plate of the mold is fixed by bolts, and the inner mold is coated with oil once, so that the demolding is facilitated. The surface of the mould is covered by a film to prevent water evaporation and heat loss. The gas forming process is controlled within 30min-50min, and the height of the mixture is increased by nearly one time when the gas forming is finished. Standing and maintaining for 3-4 hours to obtain a blank with certain strength, and demolding and cutting.

4) Steam pressure curing:

transferring the green body into a still kettle for steam pressure curing, wherein a steam curing system is adopted: and (3) vacuumizing for 0.5h at the temperature of 180-190 ℃ until the pressure reaches-0.06 MPa, boosting the pressure for 2.5h until the pressure reaches 1.0-1.5MPa, maintaining the pressure for 8h, reducing the pressure for 1.5h until the pressure reaches normal pressure, and taking the concrete block out of the kettle to obtain the autoclaved aerated concrete block.

Example 3

The embodiment provides an autoclaved aerated concrete block prepared from building slurry/building mud cakes, which is prepared by mixing a solid dry material, aluminum paste (foaming agent) and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 30 percent of dry building mud/building mud cakes (the content of silicon dioxide is 50 percent), 34.5 percent of yellow sand, 20 percent of quicklime, 15 percent of cement and 0.5 percent of desulfurized gypsum. The aluminum powder paste accounts for 0.080 percent of the total mass of the solid dry materials. The water accounts for 72 percent of the total mass of the solid dry materials, namely the water-material ratio is 0.72. The water temperature was controlled at 40 ℃.

The preparation method of the autoclaved aerated concrete block of the embodiment is the same as that of the embodiment 1.

Example 4

The embodiment provides an autoclaved aerated concrete block prepared from building slurry/building mud cakes, which is prepared by mixing a solid dry material, aluminum paste (foaming agent) and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 40% of dry building mud/building mud cakes (the content of silicon dioxide is 50%), 23.5% of yellow sand, 25% of quicklime, 10% of cement and 1.5% of desulfurized gypsum. The aluminum powder paste accounts for 0.10 percent of the total mass of the solid dry materials. The water accounts for 75 percent of the total mass of the solid dry materials, namely the water-material ratio is 0.75. The water temperature was controlled at 40 ℃.

The preparation method of the autoclaved aerated concrete block of the embodiment is the same as that of the embodiment 1.

Comparative example 1

The invention provides an autoclaved aerated concrete block prepared by utilizing building slurry/building mud cakes, which is prepared by mixing a solid dry material, aluminum powder paste (foaming agent) and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20 percent of dry building mud/building mud cakes (the content of silicon dioxide is 50 percent), 44 percent of yellow sand, 23 percent of quicklime, 13 percent of cement and 0 percent of desulfurized gypsum. The aluminum powder paste accounts for 0.11 percent of the total mass of the solid dry materials. The water accounts for 60 percent of the total mass of the solid dry materials, namely the water-material ratio is 0.60. The water temperature was controlled at 40 ℃.

The preparation method of the autoclaved aerated concrete block of the comparative example is the same as that of the example 1.

Comparative example 2

The invention provides an autoclaved aerated concrete block prepared by utilizing building slurry/building mud cakes, which is prepared by mixing a solid dry material, aluminum powder paste (foaming agent) and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20% of dry building mud/building mud cake, 44% of yellow sand, 23% of quicklime, 13% of cement and 0% of desulfurized gypsum. The aluminum powder paste accounts for 0.12 percent of the total mass of the solid dry materials. The water accounts for 59 percent of the total mass of the solid dry materials, namely the water-material ratio is 0.59. The water temperature was controlled at 40 ℃.

The preparation method of the autoclaved aerated concrete block of the comparative example is the same as that of the example 1.

Comparative example 3

The invention provides an autoclaved aerated concrete block prepared by utilizing building slurry/building mud cakes, which is prepared by mixing a solid dry material, aluminum powder paste (foaming agent) and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20% of dry building mud/building mud cake, 41.6% of yellow sand, 15% of quicklime, 21.7% of cement and 1.7% of desulfurized gypsum. The aluminum powder paste accounts for 0.083 percent of the total mass of the solid dry materials. The water accounts for 70 percent of the total mass of the solid dry materials, namely the water-material ratio is 0.70. The water temperature was controlled at 40 ℃.

The preparation method of the autoclaved aerated concrete block of the comparative example is the same as that of the example 1.

The autoclaved aerated concrete block formulations of examples 1 to 4 and comparative examples 1 to 3 are shown in table 1 below. The autoclaved aerated concrete blocks prepared from the building slurry/mud cakes of examples 1 to 4 and comparative examples 1 to 3 were subjected to tests of compressive strength, dry bulk density and the like, and the test results are statistically shown in table 2 below.

Table 1 formulation tables for examples 1 to 4 and comparative examples 1 to 3

Table 2 statistical table of performance test results of autoclaved aerated concrete blocks

From the above table 2, it can be seen that, compared with comparative examples 1 to 3, through reasonable formulation design, the product performance indexes of examples 1 to 4 meet the requirement of A3.5B06 grade in GB11968-2006 autoclaved aerated concrete block, and can be widely applied as a novel energy-saving wall material.

Compared with the comparative examples 1 and 2, the examples 1 and 2 have good fluidity by adopting the solid dry materials, the foaming agent and the proper water-material ratio in specific proportions, are helpful for controlling the pouring and gas generation processes, and therefore, the preparation of qualified products is realized.

Compared with the comparative example 3, the doping amount of materials such as yellow sand and the like in the examples 1 and 2 is high, and the doping amount of the foaming agent is low, so that the autoclaved aerated concrete block product with proper dry density can be obtained integrally.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (5)

1. The autoclaved aerated concrete block is characterized by being prepared by mixing a solid dry material, a foaming agent and water, wherein the solid dry material comprises the following raw materials in percentage by mass: 20 to 40 percent of dry building mud/building mud cake, 23.5 to 46 percent of yellow sand, 15 to 25 percent of quicklime, 10 to 18 percent of cement and 0.5 to 1.5 percent of desulfurized gypsum; the building mud is produced in the processes of drilling pile foundation construction, underground continuous wall construction, slurry shield construction and trenchless construction, the building mud cake is a material obtained by dewatering and consolidating the building mud, the content of silicon dioxide in the dry building mud/building mud cake is 50 percent, and the foaming agent accounts for 0.07 to 0.10 percent of the total mass of the solid dry material; the water accounts for 70-75% of the total mass of the solid dry materials;

the preparation method of the autoclaved aerated concrete block comprises the following steps:

drying the building mud/building mud cake, calculating the water content of the building mud/building mud cake, and deducting the water contained in the building mud/building mud cake when weighing water;

grinding the yellow sand until the residue is not more than 10% after passing through a 0.075mm hole sieve;

weighing the raw materials;

adding water into the dry building mud/building mud cake, stirring and uniformly mixing; then adding the yellow sand and the desulfurized gypsum, and stirring and mixing uniformly; adding cement, and stirring and mixing uniformly; adding quicklime, adding a foaming agent under the stirring condition, uniformly stirring and mixing, and controlling the pouring temperature to be 40-50 ℃ to obtain a mixed material;

injecting the mixed material into a mold for gas generation and standing for pre-curing, coating the inner mold of the mold once with oil, covering the surface of the mold with a film for gas generation for 30-50min, and standing for curing for 3-4 h to obtain a blank;

and (3) moving the blank into an autoclave for autoclave curing, wherein the autoclave curing process parameters are as follows: the temperature is 180-190 ℃, the vacuum pumping is carried out for 0.5h until the pressure reaches-0.06 MPa, the pressure is increased for 2.5h until the pressure reaches 1.0-1.5MPa, the pressure is maintained for 8h, and the pressure is reduced for 1.5h until the pressure reaches normal pressure, thus obtaining the product.

2. The autoclaved aerated concrete block according to claim 1, wherein the solid dry material comprises the following raw materials in percentage by mass: 20% of dry building mud/building mud cake, 46% of yellow sand, 15% of quicklime, 18% of cement and 1% of desulfurized gypsum; the foaming agent accounts for 0.070-0.077% of the total mass of the solid dry material; the water accounts for 70% of the total mass of the solid dry material.

3. The autoclaved aerated concrete block according to claim 1 or 2, wherein the foaming agent is aluminum paste.

4. A method for preparing an autoclaved aerated concrete block as set forth in any one of claims 1 to 3, characterized by comprising the steps of:

drying the building mud/building mud cake, calculating the water content of the building mud/building mud cake, and deducting the water contained in the building mud/building mud cake when weighing water;

grinding the yellow sand until the residue is not more than 10% after passing through a 0.075mm hole sieve;

weighing raw materials according to the composition of the autoclaved aerated concrete block as set forth in any one of claims 1 to 3;

adding water into the building mud/building mud cake, stirring and uniformly mixing; then adding the yellow sand and the desulfurized gypsum, and stirring and mixing uniformly; adding cement, and stirring and mixing uniformly; adding quicklime, adding a foaming agent under the stirring condition, uniformly stirring and mixing, and controlling the pouring temperature to be 40-50 ℃ to obtain a mixed material;

injecting the mixed material into a mold for gas generation and standing for pre-curing, coating the inner mold of the mold once with oil, covering the surface of the mold with a film for gas generation for 30-50min, and standing for curing for 3-4 h to obtain a blank;

and (3) moving the blank into an autoclave for autoclave curing, wherein the autoclave curing process parameters are as follows: the temperature is 180-190 ℃, the vacuum pumping is carried out for 0.5h until the pressure reaches-0.06 MPa, the pressure is increased for 2.5h until the pressure reaches 1.0-1.5MPa, the pressure is maintained for 8h, and the pressure is reduced for 1.5h until the pressure reaches normal pressure, thus obtaining the product.

5. The method for preparing the autoclaved aerated concrete block according to claim 4, wherein in the steps of gas generation and standing precuring, a bottom plate of the mold is fixed by bolts.