CN105645901B - Light thermal-insulation sheet material prepared with construction refuse regenerated fine powder and preparation method thereof - Google Patents

Abstract

The invention discloses a lightweight thermal insulation board prepared by using regenerated fine powder of construction waste. 3 to 5 parts of foaming agent, 0.2 to 0.5 parts of foam stabilizer, 50 to 100 parts of water; the recycled fine powder of construction waste is passed through an 80-mesh sieve, and the sieve residue is ≤5%. The content of SiO ₂ and Al ₂ O ₃ in the chemical composition and ≥50%; the water glass is sodium silicate water glass, the slag is the slag that meets the requirements of the S95 standard in "Granulated Blast Furnace Slag Powder Used in Cement and Concrete" (GB/T18046-2000), and the foaming agent is hydrogen peroxide, and the foam stabilizer is calcium stearate or sodium stearate. The invention also discloses a preparation method of the light-weight thermal insulation board at the same time.

Description

Lightweight thermal insulation board prepared from construction waste recycled fine powder and preparation method thereof

technical field

The invention relates to a method for preparing a novel light-weight thermal insulation board by using regenerated fine powder of construction waste, and belongs to the fields of waste resource recycling and green building materials.

Background technique

With the continuous development of urbanization and urban construction in China, the speed of infrastructure construction is accelerating, and the output of construction waste is also growing rapidly. The National Development and Reform Commission issued the "Implementation Plan for Comprehensive Utilization of Bulk Solid Waste" in December 2011, showing that my country's construction waste output was 400 million tons in 2005, and 800 million tons in 2010, and it is still in a stage of rapid growth. Construction waste will pollute the environment, waste land, and destabilize the city. Therefore, it is very important to use construction waste as a resource.

Lightweight insulation boards include foam cement, foam concrete, aerated concrete, etc. They have low density and low thermal conductivity and are important building materials. The preparation of lightweight insulation materials from construction waste is an important way to realize the resource utilization of construction waste. Cai Anlan et al. (Research on Preparation of Foamed Concrete from Construction Waste, New Building Materials, 2010, 9:30) reported that the method of preparing foamed concrete from construction waste is: ordinary Portland cement, construction waste, EPS and admixture (expansion type Water reducer, activator, etc.) are measured and added with water to premix evenly, and then the prepared foam is added in proportion (the foaming agent is Yunqing brand cement foaming agent) and stirred to make a uniform fluid slurry, which is cast into shape. The size of the specimen is 100mm×100mm×100mm, and the standard maintenance is carried out to the corresponding age for testing. Zong Peng et al. (Research on the Preparation of Foamed Concrete from Construction Waste, Building Materials Development Orientation, 2013, 12: 51) reported that the method of preparing foamed concrete from construction waste is: 1) Prepare a foaming agent and place it in a foaming machine to prepare uniform and fine 2) according to construction waste replacing cement 10%, 20%, 30%, 35% and 50% 5 different replacement ratios, prepare construction waste and cement mixture, place in mortar mixer, stir respectively. 3) Weigh 1000g of cement and construction waste mixture according to the water-cement ratio of 0.55, measure 550ml of water, put it in a mortar mixer and stir evenly to make a slurry. 4) Weigh a certain amount of foam and add it to the evenly stirred slurry, continue to stir slowly until the foam is evenly dispersed in the slurry, the stirring time is controlled within 180s, and then pour the evenly mixed slurry to 100mm×100mm×100mm Molded in a standard mold. 5) Lightly vibrate to make the slurry fill the mold. After pouring, use a trowel to smooth the surface, cover the surface with a film to prevent the surface from drying out, and turn to maintenance. Yu Xianqiang et al. (Research on Construction Waste Recycled Fine Powder Used in Thermal Insulation Mortar, Master Thesis of Beijing University of Civil Engineering and Architecture, 2014) reported that the method of using construction waste to prepare thermal insulation mortar is: mix the weighed ingredients (cement, construction waste , silicon powder, polystyrene particles, etc.) into the stirring pot, put the stirring pot on the blender and stir slowly for 30s, then pour in the weighed water, stir slowly for 30s, stop for 15s, use a scraper to stir the stirring pot during the pause Stir in the middle to prevent the dry material that cannot be stirred by the stirring blades from existing at the bottom of the pot. After the pause, stir quickly for 45 seconds, then quickly add hydrogen peroxide (3 seconds), continue stirring for 8 seconds, quickly remove the stirring pot, and pour the slurry evenly In the trial mold (40mm×40mm×160mm), the pouring height can be controlled at 3/4 of the height of the trial mold, and let it foam naturally. After the foaming is completed, move the trial mold to the standard curing room for curing for 48 hours and dismantle it. model, to be tested.

Although some research has been done on the preparation of lightweight thermal insulation materials from construction waste, there are still many problems to be solved, such as the low activity of pozzolanic ash in construction waste, which cannot react with _Ca (OH) in cement to form calcium silicate hydrate and alumina hydrate Calcium and other cementitious materials, at the same time, the construction waste is ground very thinly, which cannot play the role of aggregate reinforcement, but will only destroy the overall structure of the cement and reduce the strength of the cement. In addition, in the existing studies, the amount of construction waste used is very low, which cannot obviously achieve the purpose of comprehensive utilization of construction waste.

In addition, the current lightweight insulation materials use cement as the cementitious material, and the production process of cement consumes a lot of energy and produces greenhouse gas CO ₂ , which is inconsistent with the current green development advocated.

Contents of the invention

The technical problem to be solved by the present invention is to provide a light-weight thermal insulation board prepared from recycled fine powder of construction waste and a corresponding preparation method.

In order to solve the above technical problems, the present invention provides a light-weight insulation board prepared from recycled fine powder of construction waste, which consists of the following components by weight:

100 parts of recycled fine powder from construction waste;

Water glass 5-15 parts (preferably 10-15 parts)

20-50 parts of slag (preferably 40-50 parts)

Foaming agent 3-5 parts (preferably 4-5 parts)

Foam stabilizer 0.2-0.5 parts (preferably 0.4-0.5 parts)

50-100 parts of water (preferably 70-100 parts);

The regenerated fine powder of construction waste is passed through an 80-mesh sieve, the sieve residue is ≤5%, and the sum of SiO ₂ and Al ₂ O ₃ contents in the chemical composition is ≥50%; the above-mentioned % are mass %;

Remarks: The regenerated fine powder of construction waste is made from waste sintered red bricks, tiles, concrete, stones, glass, etc. after crushing and processing. The above SiO ₂ and Al ₂ O ₃ contents can be tested by X-ray fluorescence spectrometer get;

The water glass is sodium silicate water glass with a modulus of 1.0 to 1.5 and a Baume degree of 40 to 50°Bé;

The slag is slag that meets the requirements of the S95 standard in "Granulated Blast Furnace Slag Powder Used in Cement and Concrete" (GB/T18046-2000);

_The foaming agent is H2O2 with a mass concentration of 38% _hydrogen peroxide;

Described foam stabilizer is calcium stearate or sodium stearate.

The present invention also simultaneously provides a preparation method for the above-mentioned light-weight insulation board (the formula is as described above), comprising the following steps:

(1) Add recycled fine powder of construction waste, slag, and foam stabilizer (all solid raw materials) into the mixing tank, and mix for 5-10 minutes at a speed of 100-200 rpm;

(2) Add water glass and water to the resultant of step (1), mix at 500-1000 rpm for 2-5 minutes, then add foaming agent, and continue mixing at 500-1000 rpm for 2-5 minutes;

(3) Inject the slurry prepared in step (2) into the forming mold, let it stand for 22-26 hours (for example, 24 hours) and demould, then autoclave for 1-2 hours, autoclave pressure 0.5-1.0MPa, temperature 150- 200°C;

(4) Cut the cured modules (that is, cut to a suitable size) to obtain light-weight insulation boards.

The invention uses regenerated fine powder of construction waste as raw material and water glass as alkali activator to prepare light-weight insulation boards. The invention has the following advantages:

1. Using recycled fine powder of construction waste as raw material to prepare lightweight thermal insulation panels can realize the recycling of waste resources, reduce the production cost of lightweight thermal insulation panels, and improve product market competitiveness;

2. The SiO ₂ and Al ₂ O ₃ components in the recycled fine powder of construction waste can be dissolved in the strong alkali water glass, and the AlO ₄ and SiO ₄ tetrahedral structural units can be precipitated, and these structural units can react with the silicate in the water glass Polymerization to generate a three-dimensional geopolymer cementitious material, thereby replacing cement and endowing the board with high strength.

3. The formula design is reasonable, and slag is introduced as an admixture to accelerate the alkali excitation speed, make the slurry coagulation speed and hydrogen peroxide foaming speed uniform, improve the foaming effect of the material, and endow the board with low apparent density and thermal conductivity.

In sum, the present invention is raw material with construction refuse fine powder, is hard accelerator with slag, under the excitation of water glass alkali, synthetic geopolymer cementitious material (that is, with slag, construction waste, water glass after the reaction geopolymer as gelling material), combined with H ₂ O ₂ foaming process, to develop lightweight insulation boards, by solving the problem of compounding construction waste fine powder and slag, greatly increasing the utilization rate of construction waste and improving the strength of the board, And through the optimization of foaming technology, the foam body has high closed porosity, small diameter, round foam body, and uniform and dense foam wall, so that the thermal insulation board has a low thermal conductivity.

The dry apparent density of the novel lightweight thermal insulation board prepared by the present invention is tested according to the provisions of GB/T 11970-1997, the compressive strength is tested according to the provisions of GB/T11971-1997, and the thermal conductivity is tested according to the provisions of GB 10294 conduct.

detailed description

The following parts refer to parts by weight.

Embodiment 1, a kind of method that prepares novel light-weight heat-insulation board with construction waste regenerated fine powder:

The formula is: 100 parts of construction waste regenerated fine powder (through 80 mesh sieve, sieve residue ≤ 5%, the sum of SiO ₂ and Al ₂ O ₃ content in the chemical composition is 50%); sodium silicate water glass (modulus 1.5, Baume degree 50°Bé) 5 parts, slag (S95 grade) 20 parts, industrial hydrogen peroxide (concentration 38%) 3 parts, calcium stearate 0.2 part, water 50 parts.

Industrial hydrogen peroxide is used as a foaming agent, and calcium stearate is used as a foam stabilizer.

The production process is to carry out the following steps in sequence:

(1) Add solid raw materials such as construction waste regenerated fine powder, slag, and foam stabilizer to the mixing tank according to the amount, mix for 5 minutes, and rotate at 200 rpm;

(2) Add water glass and water to the resultant of step (1), add foaming agent after mixing at 500 rpm for 5 minutes, and continue mixing at 500 rpm for 5 minutes;

(3) Inject the slurry prepared in step (2) into the forming mold, let it stand for 24 hours, and demould it, then autoclave for 1 hour, the autoclave pressure is 1.0 MPa, and the temperature is 200°C;

(4) Cut the cured module to a suitable size plate (50cm×50cm×5cm).

Sheet properties: dry apparent density 800kg/m ³ , compressive strength 2MPa, thermal conductivity 0.15W/(m·K).

Embodiment 2, a kind of method that prepares novel light-weight heat-insulation board with the regenerated fine powder of construction waste:

The formula is: 100 parts of construction waste regenerated fine powder (through 80 mesh sieve, sieve residue ≤ 5%, the sum of SiO ₂ and Al ₂ O ₃ content in the chemical composition is 60%); sodium silicate water glass (modulus 1.2, Baume degree 50 ° Bé) 10 parts, slag (S95 grade) 40 parts, industrial hydrogen peroxide (concentration 38%) 5 parts, sodium stearate 0.5 part, water 70 parts.

Industrial hydrogen peroxide is used as a foaming agent, and sodium stearate is used as a foam stabilizer.

Production process is equal to embodiment 1.

Sheet properties: dry apparent density 700kg/m ³ , compressive strength 5MPa, thermal conductivity 0.11W/(m·K).

Embodiment 3, a kind of method that prepares novel light-weight heat-insulation board material with regenerated fine powder of construction waste:

The formula is: 100 parts of construction waste regenerated fine powder (through 80 mesh sieve, sieve residue ≤ 5%, the sum of SiO ₂ and Al ₂ O ₃ content in chemical composition is 65%); sodium silicate water glass (modulus 1.0, Baume degree 40°Bé) 15 parts, slag (S95 grade) 50 parts, industrial hydrogen peroxide (concentration 38%) 4 parts, sodium stearate 0.4 part, water 80 parts.

Industrial hydrogen peroxide is used as a foaming agent, and sodium stearate is used as a foam stabilizer.

Production process is equal to embodiment 1.

Sheet properties: dry apparent density 600kg/m ³ , compressive strength 6MPa, thermal conductivity 0.08W/(m·K).

Embodiment 4, a kind of method that prepares novel light-weight heat-insulation board with the regenerated fine powder of construction waste:

The formula is: 100 parts of construction waste regenerated fine powder (through 80 mesh sieve, sieve residue ≤ 5%, the sum of SiO ₂ and Al ₂ O ₃ content in the chemical composition is 70%); sodium silicate water glass (modulus 1.0, Baume degree 40°Bé) 15 parts, slag (S95 grade) 50 parts, industrial hydrogen peroxide (concentration 38%) 5 parts, calcium stearate 0.5 part, water 100 parts.

Industrial hydrogen peroxide is used as a foaming agent, and calcium stearate is used as a foam stabilizer.

Production process is equal to embodiment 1.

Sheet properties: dry apparent density 550kg/m ³ , compressive strength 6MPa, thermal conductivity 0.07W/(m·K).

Embodiment 5, a kind of method that prepares novel light-weight heat-insulation board with the regenerated fine powder of construction waste:

The formula is: 100 parts of recycled fine powder of construction waste (through 80 mesh sieve, sieve residue ≤ 5%, the sum of SiO ₂ and Al ₂ O ₃ content in chemical composition is 60%); sodium silicate water glass (modulus 1.0, Baume degree 40°Bé) 12 parts, slag (S95 grade) 35 parts, industrial hydrogen peroxide (concentration 38%) 3.5 parts, calcium stearate 0.25 part, water 100 parts.

Industrial hydrogen peroxide is used as a foaming agent, and calcium stearate is used as a foam stabilizer.

Production process is equal to embodiment 1.

Sheet properties: dry apparent density 550kg/m ³ , compressive strength 2MPa, thermal conductivity 0.10W/(m·K).

Comparative example 1,

In embodiment 4, "regenerated fine powder of construction waste (over 80 mesh sieves, sieve residue ≤ ₅ %, SiO ₂ , Al ₂ O content sum 70% in the chemical composition)" is changed to "regenerated fine powder of construction waste ( Pass through a 80-mesh sieve, the sieve residue ≤ 5%, the sum of SiO ₂ and Al ₂ O ₃ contents in the chemical composition is 40%), and the rest are the same as in Example 4.

Sheet properties: dry apparent density 580kg/m ³ , compressive strength 3MPa, thermal conductivity 0.09W/(m·K).

Comparative example 2,

In embodiment 4, "regenerated fine powder of construction waste (over 80 mesh sieves, sieve residue ≤ ₅ %, SiO ₂ , Al ₂ O content sum 70% in the chemical composition)" is changed to "regenerated fine powder of construction waste ( Pass through 80 mesh sieve, sieve residue≤8%, the sum of SiO ₂ and Al ₂ O ₃ contents in the chemical composition is 20%), and the rest are the same as in Example 4.

Sheet properties: dry apparent density 600kg/m ³ , compressive strength 1MPa, thermal conductivity 0.12W/(m·K).

Comparative example 3,

"Sodium silicate water glass (modulus 1.0, Baume degree 40 ° of Be) 15 parts" in embodiment 4 is changed to "sodium silicate water glass (modulus 0.8, Baume degree of 40 ° of Be) 15 parts", The rest are identical to Example 4.

Sheet properties: dry apparent density 650kg/m ³ , compressive strength 2MPa, thermal conductivity 0.12W/(m·K).

Comparative example 4,

In embodiment 4, "sodium silicate water glass (modulus 1.0, Baume degree 40 ° of Be) 15 parts" is changed to "sodium silicate water glass (modulus 1.8, Baume degree of 40 ° of Be) 15 parts", The rest are identical to Example 4.

Sheet properties: dry apparent density 900kg/m ³ , compressive strength 2MPa, thermal conductivity 0.09W/(m·K).

Comparative example 5,

In embodiment 4, "50 parts of slag (S95 grade)" is changed to "15 parts of slag (S95 grade)", and the rest are identical to embodiment 4.

Sheet properties: dry apparent density 650kg/m ³ , compressive strength 0.8MPa, thermal conductivity 0.21W/(m·K).

Comparative example 6,

In the production process of Example 4, the "subsequent autoclaved curing for 1 hour, autoclaved pressure of 1.0 MPa, and temperature of 200 ° C;" was changed to "subsequent autoclaved curing of 1.5 h, autoclaved pressure of 0.3 MPa, and temperature of 140 ° C", and the rest were implemented in the same manner Example 4.

Sheet properties: dry apparent density 580kg/m ³ , compressive strength 2MPa, thermal conductivity 0.08W/(m·K).

Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (2)

1. The light-weight insulation board prepared from the recycled fine powder of construction waste is characterized in that it is composed of the following components by weight: The regenerated fine powder of construction waste is passed through an 80-mesh sieve, the sieve residue is ≤5%, and the sum of SiO ₂ and Al ₂ O ₃ contents in the chemical composition is 70%; the above-mentioned % are mass %; Described water glass is sodium silicate water glass, modulus 1.0, Baume degree 40 ° of Bé; The slag is slag that meets the requirements of the S95 standard in "Granulated Blast Furnace Slag Powder Used in Cement and Concrete" (GB/T18046-2000); _The foaming agent is H2O2 with a mass concentration of 38% _hydrogen peroxide; Described foam stabilizer is calcium stearate. 2. The preparation method of light-weight insulation board as claimed in claim 1, is characterized in that comprising the steps: (1) Add recycled fine powder of construction waste, slag, and foam stabilizer into the mixing tank, and mix for 5-10 minutes at a speed of 100-200 rpm; (2) Add water glass and water to the resultant of step (1), mix at 500-1000 rpm for 2-5 minutes, then add foaming agent, and continue mixing at 500-1000 rpm for 2-5 minutes; (3) Inject the slurry prepared in step (2) into the forming mold, let it stand for 22-26 hours, then demould, and then autoclave for 1-2 hours, the autoclave pressure is 0.5-1.0 MPa, and the temperature is 150-200 °C; (4) Cut the cured modules to obtain lightweight insulation boards.