Foam concrete and preparation method thereof

Abstract

This application relates to the technical field of building materials, specifically disclosing a foamed concrete and its preparation method. The foamed concrete comprises the following raw materials in parts by weight: 35-45 parts water, 65-85 parts cement, 30-40 parts fly ash, 1-2 parts foaming agent, 0.9-1.2 parts water reducer, 5-10 parts styrene-butadiene rubber latex, and 5-15 parts reinforcing filler. The reinforcing filler comprises graphene, ethanol, and dimethylvinylethoxysilane. In this application, ethanol is used as the solvent, and dimethylvinylethoxysilane is used to modify the graphene, allowing it to be evenly dispersed in the system. After dehydration, the styrene-butadiene rubber latex forms a network structure that interconnects the cement matrix. Dimethylvinylethoxysilane promotes the formation of the network structure, and the hardness of the graphene is utilized to improve the compressive strength of the resulting foamed concrete.

Description

Technical Field

[0001] The present application relates to the technical field of building materials, and in particular to a foamed concrete and a preparation method thereof. Background Art

[0002] Foamed concrete is a new lightweight thermal insulation material with a large number of closed pores. The foaming agent is mechanically expanded through a foaming machine's foaming system, uniformly mixed with cement slurry, and then pumped through the machine's pumping system for cast-in-place construction or mold forming. After natural curing, the resulting material is a lightweight, thermally insulating material with a large number of closed pores. However, after hardening, commonly used foamed concrete is prone to surface cracking, and its absorption and shrinkage rates increase, which affects the concrete's compressive strength. Summary of the Invention

[0003] In order to improve the compressive strength of the prepared concrete, the present application provides a foamed concrete and a preparation method thereof.

[0004] In the first aspect, the present application provides a foamed concrete, which adopts the following technical solution:

[0005] A foamed concrete comprises raw materials of the following components in parts by weight: 35-45 parts of water, 65-85 parts of cement, 30-40 parts of fly ash, 1-2 parts of a foaming agent, 0.9-1.2 parts of a water reducer, 5-10 parts of styrene-butadiene rubber emulsion, and 5-15 parts of a reinforcing filler; the raw materials of the reinforcing filler comprise graphene, ethanol, and dimethylvinylethoxysilane.

[0006] By adopting the above technical solution, foaming is carried out using a foaming agent to produce foamed concrete; ethanol is used as a solvent, and dimethylvinylethoxysilane is used to modify graphene so that the graphene can be evenly dispersed in the system; the styrene-butadiene rubber emulsion will form a network structure after losing water, connecting the cement base materials with each other, and dimethylvinylethoxysilane can promote the formation of the network structure. The hardness of graphene is then utilized to improve the compressive strength of the foamed concrete.

[0007] In a specific embodiment, the preparation method of the reinforcing filler comprises the following steps:

[0008] Dimethylvinylethoxysilane, ethanol and water are stirred and mixed uniformly to obtain a spraying liquid; graphene is stirred, and during the stirring process, the spraying liquid is sprayed on the graphene, and dried to obtain a reinforcing filler.

[0009] By adopting the above technical solution, dimethylvinylethoxysilane is first dissolved in ethanol, then sprayed on the surface of graphene, dried, and the dimethylvinylethoxysilane coats the graphene to complete the modification of the graphene and obtain a reinforcing filler.

[0010] In a specific embodiment, the weight ratio of the dimethylvinylethoxysilane to the graphene is 1:(60-70).

[0011] By adopting the above technical solution, the present application further defines the ratio of dimethylvinylethoxysilane to graphene, so that dimethylvinylethoxysilane can better coat the graphene, thereby improving the modification effect on the graphene.

[0012] In a specific embodiment, the foaming agent includes a mixture of sodium α-olefin sulfonate, silicone polyether emulsion, and hydroxypropyl methylcellulose.

[0013] By adopting the above technical solution, sodium α-olefin sulfonate has a higher foaming effect, the silicone resin polyether emulsion can make the formed bubbles lasting and stable, and the hydroxypropyl methylcellulose makes the bubbles evenly dispersed in the system, thereby improving the performance of the prepared concrete.

[0014] In a specific embodiment, the weight ratio of the sodium α-olefin sulfonate, the silicone resin polyether emulsion, and the hydroxypropyl methylcellulose is 1:(0.4-0.6):(0.8-1.2).

[0015] By adopting the above technical solution, the present application further defines the ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose in the foaming agent, thereby further improving the foaming effect of concrete.

[0016] In a specific embodiment, the raw materials of the concrete further include 5 to 15 parts by weight of ceramsite.

[0017] By adopting the above technical solution, the density of ceramsite is small and the hardness is high, so adding ceramsite to the raw materials can further improve the compressive strength of concrete.

[0018] In a specific embodiment, the water reducer includes a polycarboxylate water reducer.

[0019] In a second aspect, the present application provides a method for preparing foamed concrete, which adopts the following technical solution:

[0020] A method for preparing foamed concrete comprises the following steps:

[0021] Adding water, fly ash, water reducing agent, styrene-butadiene rubber emulsion, reinforcing filler and ceramsite to cement, stirring and mixing uniformly to obtain a mixture;

[0022] Sodium α-olefin sulfonate, silicone resin polyether emulsion and hydroxypropyl methylcellulose are first stirred and mixed uniformly to obtain a foaming agent; the foaming agent is added to the mixture, stirred and mixed uniformly to obtain a finished material, and then the finished material is poured into a mold and allowed to stand for foaming to obtain foam concrete.

[0023] By adopting the above technical solution and utilizing the above method, concrete with higher compressive strength can be produced.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. In this application, ethanol is used as a solvent, and dimethylvinylethoxysilane is used to modify graphene, so that the graphene can be evenly dispersed in the system; after losing water, the styrene-butadiene rubber emulsion forms a network structure, connecting the cement substrates to each other. Dimethylvinylethoxysilane can promote the formation of the network structure, and the hardness of the graphene is then utilized to improve the compressive strength of the foamed concrete;

[0026] 2. The foaming agent in this application, sodium α-olefin sulfonate, has a high foaming effect, the silicone resin polyether emulsion can make the formed bubbles lasting and stable, and the hydroxypropyl methylcellulose allows the bubbles to be evenly dispersed in the system, thereby improving the performance of the resulting concrete;

[0027] 3. The method of the present application comprises the following steps: firstly mixing cement, water, fly ash, water reducing agent, styrene-butadiene rubber emulsion, reinforcing filler and ceramsite to obtain a mixture; then mixing sodium α-olefin sulfonate, silicone resin polyether emulsion and hydroxypropyl methylcellulose to obtain a foaming agent; and finally adding the foaming agent to the mixture, mixing and foaming the mixture to obtain foamed concrete with good compressive properties. DETAILED DESCRIPTION

[0028] The present application is further described in detail below with reference to the embodiments.

[0029] All raw materials in the examples are commercially available. Silicone resin polyether emulsion was provided by Hubei Kewode Chemical Co., Ltd., EINECS No.: 205-355-7; polycarboxylate superplasticizer was provided by Shanghai Puzhen Biotechnology Co., Ltd.

[0030] Preparation Example

[0031] Preparation Example 1

[0032] Preparation Example 1 provides a method for preparing a reinforcing filler, comprising the following steps:

[0033] Dimethylvinylethoxysilane, ethanol and water are stirred and mixed uniformly to obtain a spray liquid; graphene is added into a high-speed mixer, and the spray liquid is sprayed on the graphene during the stirring process. After spraying, the mixture is stirred for 0.5 hours, and then dried at 50°C for 2 hours to obtain a reinforcing filler; the weight ratio of dimethylvinylethoxysilane, ethanol and water in the spray liquid is 5:18:2; the weight ratio of dimethylvinylethoxysilane to graphene is 1:55.

[0034] Preparation Example 2

[0035] The difference between Preparation Example 2 and Preparation Example 1 is that the weight ratio of dimethylvinylethoxysilane to graphene is 1:60; the remaining steps are consistent with Preparation Example 1.

[0036] Preparation Example 3

[0037] The difference between Preparation Example 3 and Preparation Example 1 is that the weight ratio of dimethylvinylethoxysilane to graphene is 1:65; the remaining steps are consistent with Preparation Example 1.

[0038] Preparation Example 4

[0039] The difference between Preparation Example 4 and Preparation Example 1 is that the weight ratio of dimethylvinylethoxysilane to graphene is 1:70; the remaining steps are consistent with Preparation Example 1.

[0040] Preparation Example 5

[0041] The difference between Preparation Example 5 and Preparation Example 1 is that the weight ratio of dimethylvinylethoxysilane to graphene is 1:75; the remaining steps are consistent with Preparation Example 1.

[0042] Example

[0043] Example 1

[0044] Example 1 provides a method for preparing foamed concrete, comprising the following steps:

[0045] 65 kg of cement, 35 kg of water, 30 kg of fly ash, 0.9 kg of a water reducer, 5 kg of styrene-butadiene rubber emulsion, and 5 kg of the reinforcing filler in Preparation Example 1 were added to a cement mixer and stirred to obtain a mixture; wherein the water reducer was a polycarboxylate water reducer;

[0046] Sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose are stirred and mixed uniformly to obtain a foaming agent; wherein the weight ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose is 1:0.3:0.6;

[0047] Add 1 kg of foaming agent to the mixture, stir and mix evenly to obtain a finished material, then pour the finished material into a mold, let it stand and foam to obtain foam concrete.

[0048] Examples 2-5

[0049] As shown in Table 1, the main difference between Examples 2-5 and Example 1 is the different selection of reinforcing fillers.

[0050] Table 1 Selection of reinforcing fillers in Examples 2-5

[0051] sample Selection of reinforcing fillers Example 1 Preparation Example 1 Example 2 Preparation Example 2 Example 3 Preparation Example 3 Example 4 Preparation Example 4 Example 5 Preparation Example 5

[0052] Example 6

[0053] The difference between Example 6 and Example 3 is that the weight ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose in the foaming agent is 1:0.4:0.8; the remaining steps are consistent with Example 3.

[0054] Example 7

[0055] The difference between Example 7 and Example 3 is that the weight ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose in the foaming agent is 1:0.5:1.0; the remaining steps are consistent with Example 3.

[0056] Example 8

[0057] The difference between Example 8 and Example 3 is that the weight ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose in the foaming agent is 1:0.6:1.2; the remaining steps are consistent with Example 3.

[0058] Example 9

[0059] The difference between Example 9 and Example 3 is that the weight ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose in the foaming agent is 1:0.7:1.4; the remaining steps are consistent with Example 3.

[0060] Example 10

[0061] Example 10 provides a method for preparing foamed concrete, comprising the following steps:

[0062] 75 kg of cement, 40 kg of water, 35 kg of fly ash, 1.05 kg of a water reducer, 8 kg of styrene-butadiene rubber emulsion, and 10 kg of the reinforcing filler in Preparation Example 3 were added to a cement mixer and stirred and mixed uniformly to obtain a mixture; wherein the water reducer was a polycarboxylate water reducer; sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose were stirred and mixed uniformly to obtain a foaming agent; wherein the weight ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose was 1:0.5:1.0;

[0063] 1.5 kg of foaming agent was added to the mixture, stirred and mixed evenly to obtain a finished material, and then the finished material was poured into a mold and allowed to stand for foaming to obtain foamed concrete.

[0064] Example 11

[0065] Example 11 provides a method for preparing foamed concrete, comprising the following steps:

[0066] 85 kg of cement, 45 kg of water, 40 kg of fly ash, 1.2 kg of a water reducer, 10 kg of styrene-butadiene rubber emulsion, and 15 kg of the reinforcing filler in Preparation Example 3 were added to a cement mixer and stirred and mixed uniformly to obtain a mixture; wherein the water reducer was a polycarboxylate water reducer; sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose were stirred and mixed uniformly to obtain a foaming agent; wherein the weight ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose was 1:0.5:1.0;

[0067] 2 kg of foaming agent is added to the mixture, stirred and mixed evenly to obtain a finished material, and then the finished material is poured into a mold, left to stand for foaming, and foamed concrete is obtained.

[0068] Example 12

[0069] The difference between Example 12 and Example 10 is that 75 kg of cement, 40 kg of water, 35 kg of fly ash, 1.05 kg of water reducer, 8 kg of styrene-butadiene rubber emulsion, 10 kg of the reinforcing filler in Preparation Example 3, and 10 kg of ceramsite are added to a cement mixer, and the mixture is stirred and mixed evenly to obtain a mixture; the remaining steps are consistent with Example 10.

[0070] Comparative Example

[0071] Comparative Example 1

[0072] The difference between Comparative Example 1 and Example 1 is that 65 kg of cement, 35 kg of water, 30 kg of fly ash, 0.9 kg of water reducer, and 10 kg of styrene-butadiene rubber emulsion are added to a cement mixer, and stirred and mixed uniformly to obtain a mixture; the remaining steps are consistent with Example 1.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Example 1 is that 65 kg of cement, 35 kg of water, 30 kg of fly ash, 0.9 kg of water reducer, and 10 kg of the reinforcing filler in Preparation Example 1 are added to a cement mixer, stirred and mixed evenly to obtain a mixture; the remaining steps are consistent with Example 1.

[0075] Comparative Example 3

[0076] The difference between Comparative Example 3 and Example 1 is that 65 kg of cement, 35 kg of water, 30 kg of fly ash, 0.9 kg of water reducer, 5 kg of styrene-butadiene rubber emulsion, and 5 kg of graphene are added to a cement mixer, and the mixture is stirred and mixed evenly to obtain a mixture; the remaining steps are consistent with Example 1.

[0077] Performance test compressive strength: According to JG / T266-2011 "Standard Specification for Foam Concrete", the 28d compressive strength of foam concrete is tested.

[0078] Table 2 Performance test results of foam concrete

[0079] sample Compressive strength (MPa) Example 1 2.83 Example 2 3.52 Example 3 3.68 Example 4 3.60 Example 5 2.76 Example 6 4.23 Example 7 4.35 Example 8 4.35 Example 9 3.49 Example 10 4.43 Example 11 4.41 Example 12 4.76 Comparative Example 1 2.15 Comparative Example 2 2.26 Comparative Example 3 2.40

[0080] Combining Example 1 and Comparative Examples 1-3, the compressive strength of the foamed concrete in Example 1 is the highest. It can be seen that when preparing concrete, graphene modified with dimethylvinylethoxysilane and styrene-butadiene rubber emulsion are added at the same time. After losing water, the styrene-butadiene rubber emulsion forms a network structure, which connects the cement substrates to each other. The modified graphene can be evenly dispersed in the system and can promote the formation of the network structure. The hardness of the graphene itself is then utilized to improve the compressive strength of the foamed concrete.

[0081] In combination with Examples 1-5, the compressive strength of the foamed concrete in Examples 2-4 is relatively high. It can be seen that when graphene is modified using dimethylvinylethoxysilane, the ratio of dimethylvinylethoxysilane to graphene is preferably 1: (60-70), and dimethylvinylethoxysilane has a good coating effect on graphene, thereby improving the dispersion performance of graphene, thereby improving the compressive strength of the foamed concrete.

[0082] Combining Example 3 and Examples 6-9, the compressive strength of the foamed concrete in Example 6-8 is relatively high. It can be seen that when preparing concrete, the ratio of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose in the foaming agent is preferably 1: (0.4-0.6): (0.8-1.2), which makes the foaming effect of the concrete better, thereby further improving the performance of the foamed concrete.

[0083] Combining Example 7, Example 10 and Example 11, the compressive strength of the foamed concrete in Example 7, Example 10 and Example 11 is not much different, so when preparing concrete, increasing the amount of raw materials used has little effect on the compressive strength of the foamed concrete.

[0084] Combining Example 10 and Example 12, the compressive strength of the foamed concrete in Example 12 is higher. It can be seen that when preparing concrete, ceramsite is added to the raw materials. The density of ceramsite is small and the hardness is high, which can further improve the compressive strength of the foamed concrete.

[0085] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A foamed concrete, characterized in that: The raw materials of the concrete include the following components in parts by weight: 35-45 parts of water, 65-85 parts of cement, 30-40 parts of fly ash, 1-2 parts of foaming agent, 0.9-1.2 parts of water reducer, 5-10 parts of styrene-butadiene rubber emulsion, and 5-15 parts of reinforcing filler; the raw materials of the reinforcing filler include: graphene, ethanol, and dimethylvinylethoxysilane; the foaming agent includes a mixture of sodium α-olefin sulfonate, silicone resin polyether emulsion, and hydroxypropyl methylcellulose; the weight ratio of the sodium α-olefin sulfonate, the silicone resin polyether emulsion, and the hydroxypropyl methylcellulose is 1: (0.4-0.6): (0.8-1.2); the preparation method of the reinforcing filler includes the following steps: Dimethylvinylethoxysilane, ethanol, and water are stirred and mixed uniformly to obtain a spraying liquid; graphene is stirred, and during the stirring process, the spraying liquid is sprayed on the graphene, and dried to obtain a reinforcing filler; the weight ratio of the dimethylvinylethoxysilane to the graphene is 1: (60-70).

2. The foamed concrete according to claim 1, wherein: The raw materials of the concrete also include 5 to 15 parts by weight of ceramsite.

3. The foamed concrete according to claim 1, wherein: The water reducer includes a polycarboxylate water reducer.

4. A method for preparing foamed concrete according to claim 2, characterized in that: The following steps are involved: Adding water, fly ash, water reducing agent, styrene-butadiene rubber emulsion, reinforcing filler and ceramsite to cement, stirring and mixing uniformly to obtain a mixture; Sodium α-olefin sulfonate, silicone resin polyether emulsion and hydroxypropyl methylcellulose are stirred and mixed uniformly to obtain a foaming agent; Add the foaming agent to the mixture, stir and mix evenly to obtain the finished material, then pour the finished material into a mold, let it stand and foam to obtain foam concrete.