Building demolition garbage tailing lightweight thermal insulation building block / thermal insulation wallboard and preparation method thereof

Abstract

The invention provides a building demolition garbage tailing lightweight thermal insulation building block / thermal insulation wallboard and a preparation method thereof, and relates to the technical field of waste resource utilization. The building demolition garbage tailing lightweight thermal insulation building block / thermal insulation wallboard provided by the invention is prepared from the following raw materials: ordinary Portland cement, building demolition garbage tailing powder, water, a water reducing agent and a nano foaming agent. The building demolition garbage tailings comprise waste concrete, waste bricks, waste gypsum and the like which are complex in components and difficult to treat, active components in the building demolition garbage tailings are fully utilized, a hydration reaction can be carried out under the action of an exciting agent to generate a hydration product, and the internal binding power of the material is enhanced; and the nano foaming agent is adopted and has good stability, early coagulation of the slurry can be achieved, foam collapse is effectively avoided, and the strength of the building demolition garbage tailings is improved. According to the invention, the building material with excellent thermal insulation performance is developed by utilizing the building demolition garbage tailings, so that the consumption of natural resources is reduced, and the pollution of wastes to the environment is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of waste resource utilization, and in particular to a lightweight thermal insulation building block / thermal insulation wallboard made from building demolition waste tailings and a preparation method thereof. Background Art

[0002] With the development of the construction industry, the demand for lightweight insulation materials is growing. Traditional building insulation materials, such as polystyrene boards, have problems such as burning hazards, environmental pollution and waste of resources. Although there are some attempts to use foamed concrete to solve these problems, traditional foamed concrete uses a large amount of raw materials such as cement, sand and gravel in its production, which does not meet the expectations of development in terms of sustainability and environmental protection. Therefore, it is necessary to develop a new foamed concrete insulation material to solve the shortcomings of traditional insulation materials. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a lightweight thermal insulation block / insulation wallboard made of building demolition waste tailings and a preparation method thereof. The present invention utilizes a large amount of building demolition waste tailings to develop a block / insulation wallboard with excellent thermal insulation performance, thereby reducing the consumption of natural resources and helping to reduce the pollution caused by waste to the environment.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a lightweight thermal insulation building block / thermal insulation wallboard made of building demolition waste tailings, the preparation raw materials of which include: ordinary silicate cement, building demolition waste tailings powder, water, water reducing agent and nano foaming agent;

[0006] The mass ratio of the construction demolition waste tailings powder to ordinary Portland cement is 7:3-3:7, the mass ratio of the water to the total mass of ordinary Portland cement and the construction demolition waste tailings powder is 0.2:1, the mass of the water reducer is 0.1-0.3% of the total mass of the construction demolition waste tailings powder and ordinary Portland cement; the mass of the nano foaming agent is 4-8% of the total mass of the construction demolition waste tailings powder and ordinary Portland cement.

[0007] Preferably, the ordinary Portland cement is PO 42.5 cement.

[0008] Preferably, the construction demolition waste tailing powder is obtained by pre-treating the construction demolition waste tailing, wherein the pre-treatment includes sorting, crushing and screening, and the screening is through a sieve of 60-200 meshes.

[0009] Preferably, the building demolition waste tailings include waste concrete, waste bricks and waste gypsum.

[0010] Preferably, the nano foaming agent comprises the following components in percentage by weight: 0.1-1% sodium dodecylbenzene sulfonate, 0.1-1% nano kaolin, 0.05-1% cellulose reinforcing agent, and the balance water; the cellulose reinforcing agent comprises methyl cellulose and hydroxypropyl methyl cellulose.

[0011] The present invention provides a method for preparing lightweight thermal insulation blocks / thermal insulation wallboards made of building demolition waste tailings as described in the above technical solution, comprising the following steps:

[0012] Mechanically foaming the nano foaming agent to obtain prefabricated foam;

[0013] Mixing the building demolition waste tailings powder, ordinary Portland cement, water and a water reducing agent to obtain a mixture;

[0014] mixing the mixed material with prefabricated foam to obtain concrete foam;

[0015] The concrete foam is sequentially molded and cured to obtain the building demolition waste tailings lightweight insulation building block / insulation wallboard.

[0016] Preferably, the air pressure of the mechanical foaming is 0.3-3 MPa, and the density of the prefabricated foam is 35-70 g / L.

[0017] Preferably, the mixing of the mixed material and the prefabricated foam is carried out under stirring, and the stirring rate is 10 r / min.

[0018] Preferably, the mold forming includes mold installation and pre-curing, and the mold is removed after the pre-curing; the pre-curing is natural curing, and the time of the natural curing is 0.5 to 2 days.

[0019] Preferably, the curing is standard curing, and the time of the standard curing is 25 to 28 days.

[0020] The invention provides a lightweight thermal insulation building block / thermal insulation wallboard made of building demolition waste tailings. The raw materials for preparation include ordinary Portland cement, building demolition waste tailings powder, water, a water reducing agent and a nano foaming agent. The mass ratio of the building demolition waste tailings powder to the ordinary Portland cement is 7:3-3:7, the mass ratio of the water to the total mass of the ordinary Portland cement and the building demolition waste tailings powder is 0.2:1, the mass of the water reducing agent is 0.1-0.3% of the total mass of the building demolition waste tailings powder and the ordinary Portland cement, and the mass of the nano foaming agent is 4-8% of the total mass of the building demolition waste tailings powder and the ordinary Portland cement. Building demolition waste tailings include waste concrete, waste bricks, waste gypsum, etc., which are complex in composition and difficult to handle. The present invention makes full use of the active ingredients in building demolition waste tailings, such as silicate minerals. Under the action of an activator (ordinary Portland cement), a hydration reaction can occur to generate hydration products, thereby enhancing the internal bonding force of the material; and the present invention adopts a nano foaming agent, which has good stability and can achieve early setting of the slurry, effectively avoiding bubbling, and achieving the improvement of the strength of building demolition waste tailings. The present invention utilizes building demolition waste tailings to develop building materials with excellent performance, which have excellent thermal insulation performance, can effectively insulate and heat-preserve, and improve the energy efficiency of buildings; the density is low, but it has sufficient strength, can meet the requirements of the building structure, and reduces the load of the building itself; it has good fire resistance, can effectively prevent the spread of fire, and improve the safety of the building. The present invention reduces the consumption of natural resources and helps to reduce the pollution caused by waste to the environment.

[0021] The present invention provides a method for preparing lightweight thermal insulation blocks / thermal insulation wallboards made of building demolition waste tailings as described in the above technical solution, which has a simple and efficient process flow and can quickly realize large-scale production.

[0022] The results of the examples show that the lightweight thermal insulation blocks / thermal insulation wallboards made of building demolition waste tailings provided by the present invention have a 28d strength of 4.4-14.2 MPa and a density of 780-1300 kg / m 3 , the thermal conductivity is 0.17~0.38W / (m·K). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic diagram of a process for preparing lightweight thermal insulation wall panels from building demolition waste tailings according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention provides a lightweight thermal insulation building block / thermal insulation wallboard made of building demolition waste tailings, the preparation raw materials of which include: ordinary silicate cement, building demolition waste tailings powder, water, water reducing agent and nano foaming agent;

[0025] The mass ratio of the construction demolition waste tailings powder to ordinary Portland cement is 7:3-3:7, the mass ratio of the water to the total mass of ordinary Portland cement and the construction demolition waste tailings powder is 0.2:1, the mass of the water reducer is 0.1-0.3% of the total mass of the construction demolition waste tailings powder and ordinary Portland cement; the mass of the nano foaming agent is 4-8% of the total mass of the construction demolition waste tailings powder and ordinary Portland cement.

[0026] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0027] The raw materials for preparing the lightweight thermal insulation blocks / thermal insulation wallboards made of building demolition waste tailings provided by the present invention include ordinary Portland cement. In the present invention, the ordinary Portland cement is preferably PO 42.5 cement. The present invention adopts ordinary Portland cement, which will not have rapid hardening and early strength, and has a slower hydration speed than sulphoaluminate cement, and will not have cracks.

[0028] The raw materials for preparing lightweight insulation blocks / insulation wallboards of construction demolition waste tailings provided by the present invention include construction demolition waste tailings powder. In the present invention, the construction demolition waste tailings powder is preferably obtained by pre-treating construction demolition waste tailings (CDW); the construction demolition waste tailings preferably include waste concrete, waste bricks and waste gypsum. The composition of construction waste is complex, and the particle size and shape of the waste are different. Pre-treatment is required to obtain raw materials suitable for preparing lightweight insulation building materials. In the present invention, the pre-treatment preferably includes sorting, crushing and screening; the sorting specifically removes unusable materials such as metals, wood, etc.; the crushing preferably uses a hammer crusher, and the screening is preferably through a 60-200 mesh sieve. The present invention controls the particle size of the construction demolition waste tailings powder, which helps the silicate and calcium oxide components therein to fully react with cement. In the present invention, the mass ratio of the construction demolition waste tailings powder to ordinary Portland cement is 7:3-3:7, preferably 7:3, 3:2 or 3:7.

[0029] The raw materials for preparing the lightweight thermal insulation building blocks / thermal insulation wallboards made of building demolition waste tailings provided by the invention include water, and the ratio of the mass of the water to the total mass of ordinary silicate cement and building demolition waste tailings powder is 0.2:1.

[0030] The gangue lightweight insulation block / insulation wallboard provided by the present invention comprises a water reducer, the mass of which is 0.1-0.3%, preferably 0.2-0.3%, of the total mass of building demolition waste tailing powder and ordinary Portland cement. In the present invention, the water reducer is preferably a polycarboxylate water reducer.

[0031] The raw materials for preparing lightweight thermal insulation blocks / wallboards made of building demolition waste tailings provided by the invention include a nano foaming agent, which includes the following components in percentage by mass: 0.1-1% sodium dodecylbenzene sulfonate, 0.1-1% nano kaolin, 0.05-1% cellulose reinforcing agent, and the balance water.

[0032] In the present invention, the mass content of sodium dodecylbenzene sulfonate in the nano foaming agent is preferably 0.1-0.2%. In the present invention, the mass percentage of nano kaolin in the nano foaming agent is preferably 0.1-0.2%, and the particle size of the nano kaolin is preferably 40-100 nm, more preferably 50-80 nm. In the present invention, the mass percentage of the cellulose reinforcing agent in the nano foaming agent is preferably 0.05-0.5%, more preferably 0.06-0.1%. In the present invention, the cellulose reinforcing agent preferably includes methyl cellulose and hydroxypropyl methyl cellulose, and the relative molecular weights of the methyl cellulose and hydroxypropyl methyl cellulose are independently preferably 50000-300000, more preferably 100000-200000; the mass ratio of the methyl cellulose to the hydroxypropyl methyl cellulose is preferably 1:3.

[0033] The present invention has no special requirements for the preparation method of the nano foaming agent, and the components can be mixed evenly. In the embodiment of the present invention, the sodium dodecylbenzene sulfonate, nano kaolin and cellulose reinforcing agent are also called foaming powder, and the nano foaming agent is also called foaming liquid.

[0034] In the present invention, the mass of the nano foaming agent is 4-8%, preferably 6-8%, of the total mass of the building demolition waste tailings powder and ordinary Portland cement. The present invention uses sodium dodecylbenzene sulfonate as a surfactant, nano kaolin as a foam stabilizer, and a cellulose reinforcing agent composed of methyl cellulose and hydroxypropyl methyl cellulose, so that the nano foaming agent has good stability, can achieve early setting of the slurry, effectively avoid foaming, and achieve the improvement of the strength of the building demolition waste tailings.

[0035] The present invention provides a method for preparing lightweight thermal insulation blocks / thermal insulation wallboards made of building demolition waste tailings as described in the above technical solution, comprising the following steps:

[0036] Mechanically foaming the nano foaming agent to obtain prefabricated foam;

[0037] Mixing the building demolition waste tailings powder, ordinary Portland cement, water and a water reducing agent to obtain a mixture;

[0038] mixing the mixed material with prefabricated foam to obtain concrete foam;

[0039] The concrete foam is molded and cured in sequence to obtain the building demolition waste tailings lightweight thermal insulation building block / thermal insulation wallboard.

[0040] The present invention performs mechanical foaming (i.e., physical foaming) on ​​the nano foaming agent to obtain prefabricated foam. In the present invention, the mechanical foaming is preferably performed by a foaming machine; the air pressure of the mechanical foaming is preferably 0.3-3 MPa, and the density of the prefabricated foam is preferably 35-70 g / L.

[0041] The present invention mixes the building demolition waste tailing powder, cement, water and a water reducing agent to obtain a mixture. In the present invention, the specific operation of mixing the building demolition waste tailing powder, cement, water and a water reducing agent is preferably: adding water to a mixer, then adding a water reducing agent for a first stirring and mixing, and then adding cement and building demolition waste tailing powder for a second stirring and mixing. In the present invention, the rotation speed of the first stirring and mixing is preferably 20r / min, and the stirring time is preferably 2min; the rotation speed of the second stirring and mixing is preferably 50r / min, and the clockwise and counterclockwise stirring are respectively 2 to 5min. After the cement, building demolition waste tailing powder, water and a water reducing agent are mixed, a uniform slurry is obtained, namely the mixture.

[0042] In the present invention, the fluidity of the mixture is preferably 240 to 250 mm.

[0043] After obtaining the mixture and the prefabricated foam, the present invention mixes the mixture and the prefabricated foam to obtain concrete foam. In the present invention, the mixing of the mixture and the prefabricated foam is preferably carried out under stirring, and the stirring rate is preferably 10r / min; the specific operation of mixing the mixture and the prefabricated foam is preferably: reducing the speed of the mixer containing the mixture to 10r / min, injecting the prefabricated foam into the mixture, stirring clockwise and counterclockwise for 1 to 2 minutes respectively, so that a uniform foam structure is formed in the concrete, that is, the concrete foam is obtained.

[0044] After obtaining the concrete foam, the present invention sequentially performs mold forming and curing on the concrete foam to obtain the lightweight thermal insulation blocks / insulation wall panels of the building demolition waste tailings. In the present invention, the mold forming preferably includes mold loading (i.e. pouring the concrete foam into a pre-prepared mold) and pre-curing, and compaction can also be performed after the mold loading, and the mold is removed after the pre-curing; the pre-curing is preferably natural curing, and the natural curing time is preferably 0.5 to 2 days. The present invention uses the mold forming to form concrete into a material of a certain size and shape, i.e., a block or thermal insulation wall panel. In the present invention, the curing and curing is preferably standard curing (i.e., standard curing), and the standard curing time is preferably 25 to 28 days. The present invention uses the curing and curing to ensure that the material obtains sufficient strength and stability during the hardening process. In the present invention, when preparing building blocks, the natural curing time is preferably 12 hours. After natural curing, wire cutting is performed to the required size, and then standard curing is performed. The standard curing time is more preferably 27.5 days. When preparing thermal insulation wall panels, the natural curing time is more preferably 1 day, and the standard curing time is more preferably 27 days.

[0045] The process flow of preparing lightweight thermal insulation blocks / insulation wall panels using building demolition waste tailings is simple and efficient, and can quickly achieve large-scale production. The lightweight thermal insulation blocks / insulation wall panels prepared using foamed concrete have low density, excellent thermal insulation performance and good compressive strength. Compared with traditional thermal insulation materials, they are lighter, more environmentally friendly and more energy-efficient. In addition, the foam structure of foamed concrete makes the lightweight thermal insulation blocks / insulation wall panels have better thermal insulation performance, which can effectively reduce the energy consumption of buildings and improve the energy utilization rate of buildings.

[0046] To further illustrate the present invention, the lightweight thermal insulation blocks / thermal insulation wallboards made of building demolition waste tailings and the preparation method thereof provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of protection of the present invention.

[0047] The preparation process of the nano foaming agent used in the following examples is as follows:

[0048] Sodium dodecylbenzene sulfonate is dissolved in water and stirred with a glass rod until it is dissolved to prepare a sodium dodecylbenzene sulfonate solution with a concentration of 0.1wt% (solution 1); nano kaolin (particle size 50-80nm) is dispersed in solution 1 and stirred with a glass rod until it is evenly dispersed, wherein the mass ratio of the nano kaolin to the sodium dodecylbenzene sulfonate is 1:1 (solution 2); methyl cellulose (relative molecular weight 200000) and hydroxypropyl methyl cellulose (relative molecular weight 200000) (the mass ratio of methyl cellulose to hydroxypropyl methyl cellulose is 1:3) are added to solution 2, wherein the amount of methyl cellulose and hydroxypropyl methyl cellulose is 90wt% of the nano kaolin, and stirred with a glass rod until it is evenly dispersed, and the stirring speed is 20r / min to obtain a nano foaming agent.

[0049] Example 1

[0050] A lightweight thermal insulation building block / thermal insulation wallboard made of building demolition waste tailings is prepared from the following materials: 560kg of PO 42.5 cement, 240kg of building demolition waste tailings powder, 160kg of water, 2kg of polycarboxylic acid water reducer, and 64kg of nano foaming agent, wherein the building demolition waste tailings powder is obtained by sorting, crushing, and passing through a 100-mesh sieve.

[0051] The preparation steps are as follows (process as Figure 1 shown):

[0052] (1) Weigh the required amount of water and add it into a blender.

[0053] (2) Weigh the required amount of polycarboxylate water reducer and pour it into a blender at a speed of 20 r / min for 2 min.

[0054] (3) Weigh the required cement and building demolition waste tailings powder, pour them into a mixer, and stir at 50 r / min in clockwise and counterclockwise directions for 2 to 5 minutes respectively until the slurry is uniform.

[0055] (4) The speed of the mixer was reduced to 10 r / min, and the nano foaming agent (foaming gas pressure was 0.6 MPa, and the foaming density was 60 g / L) was foamed by a foaming machine and injected into the mixer, and stirred clockwise and counterclockwise for 1 to 2 min respectively.

[0056] (5) For lightweight thermal insulation wall panels, simply inject the mixed slurry into the required mold, naturally cure for 1 day, remove the mold, and then continue standard curing for 27 days; for lightweight thermal insulation blocks, simply inject the mixed slurry into the required mold, naturally cure for 12 hours, remove the mold, and then perform wire cutting to the required size. After cutting, continue standard curing for 27.5 days.

[0057] The strength of lightweight thermal insulation blocks / wallboards made of building demolition waste tailings at 28 days (natural curing + standard curing) is 4.7-5.1MPa, and the density is 780-800kg / m 3 , the thermal conductivity is 0.17~0.20W / (m·K).

[0058] Example 2

[0059] A lightweight thermal insulation building block / thermal insulation wallboard made of building demolition waste tailings is prepared from the following materials: 320kg of PO 42.5 cement, 480kg of building demolition waste tailings powder, 160kg of water, 2kg of polycarboxylic acid water reducer, and 64kg of nano foaming agent, wherein the building demolition waste tailings powder is obtained by sorting, crushing, and passing through a 100-mesh sieve.

[0060] The preparation steps are the same as those in Example 1.

[0061] The lightweight insulation blocks / insulation wall panels made of construction demolition waste tailings have a 28d strength of 4.4-5.2MPa and a density of 960-1000kg / m 3 , the thermal conductivity is 0.26~0.27W / (m·K).

[0062] Example 3

[0063] A lightweight thermal insulation building block / thermal insulation wallboard made of building demolition waste tailings is prepared from the following materials: 240kg of PO 42.5 cement, 560kg of building demolition waste tailings powder, 160kg of water, 2kg of polycarboxylic acid water reducer, and 64kg of nano foaming agent, wherein the building demolition waste tailings powder is obtained by sorting, crushing, and passing through a 100-mesh sieve.

[0064] The preparation steps are the same as those in Example 1.

[0065] The lightweight insulation blocks / insulation wall panels made of construction demolition waste tailings have a 28d strength of 13.5-14.2MPa and a density of 1220-1300kg / m 3 , the thermal conductivity is 0.35~0.38W / (m·K).

[0066] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A lightweight thermal insulation block / thermal insulation wallboard made of building demolition waste tailings, characterized in that: The raw materials for preparation include: ordinary silicate cement, building demolition waste tailing powder, water, water reducing agent and nano foaming agent; The mass ratio of the construction demolition waste tailings powder to ordinary Portland cement is 7:3-3:7, the mass ratio of the water to the total mass of ordinary Portland cement and the construction demolition waste tailings powder is 0.2:1, the mass of the water reducer is 0.1-0.3% of the total mass of the construction demolition waste tailings powder and ordinary Portland cement; the mass of the nano foaming agent is 4-8% of the total mass of the construction demolition waste tailings powder and ordinary Portland cement.

2. The lightweight thermal insulation block / thermal insulation wallboard made of building demolition waste tailings according to claim 1 is characterized in that: The ordinary Portland cement is PO 42.5 cement.

3. The lightweight building block / insulation wallboard made of building demolition waste tailings according to claim 1 is characterized in that: The building demolition waste tailing powder is obtained by pre-treating the building demolition waste tailing, wherein the pre-treatment includes sorting, crushing and screening, and the screening is through a sieve of 60-200 meshes.

4. The lightweight thermal insulation block / thermal insulation wallboard made of building demolition waste tailings according to claim 3 is characterized in that: The building demolition waste tailings include waste concrete, waste bricks and waste gypsum.

5. The lightweight thermal insulation building block / thermal insulation wallboard made of building demolition waste tailings according to claim 1, characterized in that: The nano foaming agent comprises the following components in percentage by weight: 0.1-1% sodium dodecylbenzene sulfonate, 0.1-1% nano kaolin, 0.05-1% cellulose reinforcing agent, and the balance water; the cellulose reinforcing agent comprises methyl cellulose and hydroxypropyl methyl cellulose.

6. The method for preparing the lightweight thermal insulation building blocks / thermal insulation wallboards made of building demolition waste tailings according to any one of claims 1 to 5, characterized in that: The following steps are involved: Mechanically foaming the nano foaming agent to obtain prefabricated foam; Mixing the building demolition waste tailings powder, ordinary Portland cement, water and a water reducing agent to obtain a mixture; mixing the mixed material with prefabricated foam to obtain concrete foam; The concrete foam is sequentially molded and cured to obtain the building demolition waste tailings lightweight insulation building block / insulation wallboard.

7. The preparation method according to claim 6, characterized in that: The air pressure of the mechanical foaming is 0.3-3 MPa, and the density of the prefabricated foam is 35-70 g / L.

8. The preparation method according to claim 6, characterized in that: The mixing of the mixed material and the prefabricated foam is carried out under stirring, and the stirring rate is 10 r / min.

9. The preparation method according to claim 6, characterized in that: The mold forming includes mold installation and pre-curing, and the mold is removed after the pre-curing; the pre-curing is natural curing, and the time of the natural curing is 0.5 to 2 days.

10. The preparation method according to claim 6, characterized in that: The curing process is standard curing, and the time of the standard curing is 25 to 28 days.

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