Disclosure of Invention
The invention aims to provide construction waste foam concrete and a preparation method and application thereof, so as to solve the problems in the prior art, realize recycling of construction waste and enable the construction waste concrete to meet the application requirements of an assembly type building.
In order to achieve the purpose, the invention provides the following scheme:
one of the purposes of the invention is to provide the construction waste foam concrete, which comprises the raw materials of construction waste aggregate, a cementing material and an external charging material;
the construction waste aggregate comprises concrete and broken brick slag;
the cementing material comprises PO42.5 portland cement, calcium aluminate cement, lime and gypsum;
the external charging material comprises sodium sulfate, water glass, mineral powder, glass fiber, sodium hydroxide, a foam stabilizer and aluminum powder.
The foam stabilizer is ethylene oxide fatty alcohol ether.
Further, the construction waste foam concrete comprises the following raw material components in percentage by mass:
60% of construction waste aggregate, 15% of PO42.5 portland cement, 3% of calcium aluminate cement, 6% of lime, 6% of gypsum, 2% of sodium sulfate, 1% of water glass, 5% of mineral powder, 1% of glass fiber, 0.9% of sodium hydroxide, 0.05% of foam stabilizer and 0.05% of aluminum powder; the water-material ratio of the construction waste concrete is 0.35.
Further, the construction waste aggregate is construction waste fine aggregate with the particle size of less than or equal to 0.63mm, and the particle size grades are as follows: less than or equal to 0.16mm, more than 0.16mm to 0.315mm and more than 0.315mm to 0.63 mm.
Further, the particle size grade mass ratio of the construction waste aggregate is as follows: less than or equal to 0.16 mm: > 0.16mm-0.315 mm: 0.315mm-0.63mm ═ 0.14: 0.36: 0.5.
further, the sodium sulfate is technical grade sodium sulfate with a purity of 99.9%.
Further, the water glass modulus is 1.2.
The invention also aims to provide a preparation method of the construction waste foam concrete, which comprises the following steps:
a. weighing raw materials according to the raw material ratio;
b. mixing other raw material components except sodium hydroxide and water glass to obtain a mixture;
c. dissolving water glass and sodium hydroxide in all the mixed water, and stirring until the solid water glass and the solid sodium hydroxide are completely melted to obtain a mixed solution; the temperature of the water is normal temperature (25 ℃);
d. mixing the mixture obtained in the step b and the mixed solution obtained in the step c, and stirring to obtain slurry;
e. and d, pouring the slurry obtained in the step d into a mold (paving a proper amount of lubricating oil in the mold before pouring the slurry), and maintaining for 7-28 days under the conditions that the temperature is 60 ℃ and the humidity is 95% to obtain the building garbage concrete block.
Further, the mixing time in the step b is 2-3 min; and d, stirring for 3-4min in the step d.
In the step d, selecting an NJ-160 type double-speed small cement mortar stirrer, wherein the stirring speed is as follows: rotation is 130-150 r/min, and revolution is 55-70 r/min.
Step e, equivalently filling the concrete mixture into a mould twice, wherein the middle interval is 10s, the concrete higher than the test block is formed without using a vibrating table or a manual inserting or vibrating rod method, and the size of the used mould is 60 multiplied by 60 mm;
the invention also aims to provide application of the construction waste foam concrete in the field of fabricated buildings.
The invention discloses the following technical effects:
1. the construction waste is added into the concrete material in a large mixing amount, so that the utilization rate of the construction waste in the field of construction is greatly improved.
2. The gypsum and the lime are added in the invention, so that the stacking density of the building waste foam concrete is improved, and the activity of the building waste fine powder is excited.
3. The invention adopts a mechanical foaming mode, aluminum powder is directly added into dry materials to be stirred, and then normal temperature water is slowly added, so that the gas forming reaction is slowed down, and the block cutting and cracking caused by later foaming are avoided.
4. The invention solves the problems of low strength and poor early strength of the construction waste foam concrete by adding the glass fiber and the slag.
5. The construction waste foam concrete applied to the fabricated building, which is prepared by the invention, has the characteristics of small heat conductivity coefficient, high strength and quick solidification, and the fabricated member with excellent comprehensive performance is prepared while the construction waste is efficiently utilized.
The invention takes the concrete with the maximum proportion of the construction waste and the crushed brick slag as the aggregate to manufacture the assembly type construction member, is beneficial to reducing the burden of the construction waste disposal problem, realizes the advanced utilization of the construction waste, and integrates the idea of environmental protection and energy saving into the assembly type construction concept, thereby promoting the further development of the assembly type construction.
Detailed Description
Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.
It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
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. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.
It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.
As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including but not limited to.
The sodium sulfate used in the embodiment of the invention is industrial grade sodium sulfate with the purity of 99.9 percent; the water glass modulus was 1.2.
The particle size grade of the building rubbish aggregate in the embodiment of the invention is as follows: not more than 0.16mm, more than 0.16mm to 0.315mm, more than 0.315mm to 0.63mm, the mass ratio corresponding to different particle diameters is not more than 0.16 mm: > 0.16mm-0.315 mm: 0.315mm-0.63mm ═ 0.14: 0.36: 0.5.
example 1
The building waste foam concrete applied to the fabricated building comprises the following raw material components in percentage by mass:
60% of construction waste aggregate (crushed concrete), 15% of PO42.5 Portland cement, 3% of calcium aluminate cement, 1% of water glass, 5% of mineral powder, 6% of lime, 6% of desulfurized gypsum, 2% of sodium sulfate, 1% of glass fiber, 0.9% of sodium hydroxide, 0.05% of aluminum powder and 0.05% of ethylene oxide fatty alcohol ether; the water-material ratio in the raw material is 0.35.
The preparation method comprises the following steps:
a. weighing raw materials according to the proportion;
b. mixing and stirring the building waste aggregate, the cementing material and the additional material (without sodium hydroxide and water glass), and dry-mixing for 3min to prepare a mixture;
c. dissolving water glass and sodium hydroxide into all stirring water, wherein the temperature of the water is normal temperature (25 ℃), and uniformly stirring;
d. pouring the solution obtained in the step c into the mixture obtained in the step b, and stirring for 3min to obtain slurry; the process is carried out in an NJ-160 type double-speed small cement mortar stirrer, and the stirring speed is as follows: rotation is 150r/min, revolution is 55 r/min;
e. d, paving a proper amount of lubricating oil in the mould, and pouring the slurry prepared in the step d into the mould;
f. and curing for 7 days by a curing box under the conditions that the temperature is 60 ℃ and the humidity is 95 percent to obtain the construction waste foam concrete applied to the fabricated building.
The initial setting time of the test article is 6 hours, the performance of the test article is detected, and the result shows that: the compressive strength is 2.3MPa, and the dry density is 757g/m3The porosity was 59.9%, and the thermal conductivity was 0.172W/(m.K).
Example 2
The building waste foam concrete applied to the fabricated building comprises the following raw material components in percentage by mass:
60% of construction waste aggregate (broken brick slag), 15% of PO42.5 Portland cement, 3% of calcium aluminate cement, 1% of water glass, 5% of mineral powder, 6% of lime, 6% of desulfurized gypsum, 2% of sodium sulfate, 1% of glass fiber, 0.9% of sodium hydroxide, 0.05% of aluminum powder and 0.05% of ethylene oxide fatty alcohol ether; the water-material ratio in the raw material is 0.35.
The preparation method comprises the following steps:
a. weighing raw materials according to the proportion;
b. mixing and stirring the building waste aggregate, the cementing material and the additional material (without sodium hydroxide and water glass), and dry-mixing for 2min to prepare a mixture;
c. dissolving water glass and sodium hydroxide into all stirring water, wherein the temperature of the water is normal temperature (25 ℃), and uniformly stirring;
d. pouring the solution obtained in the step c into the mixture obtained in the step b, and stirring for 4min to obtain slurry; the process is carried out in an NJ-160 type double-speed small cement mortar stirrer, and the stirring speed is as follows: rotation is 140r/min, and revolution is 60 r/min;
e. d, paving a proper amount of lubricating oil in the mould, and pouring the slurry prepared in the step d into the mould;
f. and curing for 7 days in a curing box under the conditions that the temperature is 60 ℃ and the humidity is 95 percent to obtain the construction waste foam concrete applied to the fabricated building.
The initial setting time of the test article is 6 hours, the performance of the test article is detected, and the result shows that: the compressive strength is 2.8MPa, and the dry density is 814Kg/m3Porosity of 59.2%, heat conductivityThe coefficient was 0.187W/(m.K).
Example 3
The building waste foam concrete applied to the fabricated building comprises the following raw material components in percentage by mass:
60% of construction waste aggregate (broken brick slag: broken concrete ═ 1: 1), 15% of PO42.5 portland cement, 3% of calcium aluminate cement, 1% of water glass, 5% of mineral powder, 6% of lime, 6% of desulfurized gypsum, 2% of sodium sulfate, 1% of glass fiber, 0.9% of sodium hydroxide, 0.05% of aluminum powder and 0.05% of ethylene oxide fatty alcohol ether; the water-material ratio in the raw material is 0.35.
The preparation method comprises the following steps:
a. weighing raw materials according to the proportion;
b. mixing and stirring the building waste aggregate, the cementing material and the additional material (without sodium hydroxide and water glass), and dry-mixing for 3min to prepare a mixture;
c. dissolving water glass and sodium hydroxide into all stirring water, wherein the temperature of the water is normal temperature (25 ℃), and uniformly stirring;
d. pouring the solution obtained in the step c into the mixture obtained in the step b, and stirring for 3min to obtain slurry; the process is carried out in an NJ-160 type double-speed small cement mortar stirrer, and the stirring speed is as follows: rotation is 130r/min, and revolution is 70 r/min;
e. d, paving a proper amount of lubricating oil in the mould, and pouring the slurry prepared in the step d into the mould;
f. and curing for 7 days by a curing box under the conditions that the temperature is 60 ℃ and the humidity is 95 percent to obtain the construction waste foam concrete applied to the fabricated building.
The dry setting time of the sample is 5 hours, the performance of the sample is detected, and the result shows that: the compressive strength is 3.1MPa, and the dry density is 885Kg/m3The porosity was 58.3%, and the thermal conductivity was 0.191W/(m.K).
The above three groups of examples were designed by adjusting the proportion of recycled aggregate in the aggregate. The comparison shows that the heat preservation performance of the samples prepared by the groups is not obvious, but the differences of the compressive strength and the solidification time are large, wherein the sample prepared by the example 3 has the maximum strength, the fastest solidification and excellent heat preservation performance.
The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.