Lightweight thermal insulation concrete and preparation method thereof

Abstract

The invention discloses light heat insulation concrete which comprises the following components in parts by weight: 5-10 parts of cement, 5-8 parts of porous ceramic, 1-2 parts of diatomite, 5-8 parts of polyurethane particles, 2 parts of glass fibers, 1-2 parts of rubber emulsion, 3 parts of water and 1-2 parts of an additive. The invention also provides a method for preparing the lightweight thermal insulation concrete. The light heat insulation concrete provided by the invention has the advantages of low density, light dead weight, good heat insulation, good mechanical strength and good flame-retardant and fireproof performance, and can effectively reduce the building load, reduce the burden of a foundation structure, reduce the use amount of building materials and reduce the building cost.

Description

Technical Field

[0001] The invention belongs to the field of building materials, and particularly relates to lightweight heat-insulating concrete and a preparation method thereof. Background Art

[0002] Concrete is a composite material made of gel material, aggregate and water in appropriate proportions and hardened after a certain period of time. It is the most widely used artificial civil construction material in the world. Usually, concrete refers to cement (which can be mixed with fly ash, granulated blast furnace slag powder, silica fume) as a gelling material, sand and stone as aggregates, and water (which may contain admixtures) in a certain proportion, and the cement concrete obtained by mixing is also called ordinary concrete.

[0003] With the development of the construction industry, lightweight concrete has gradually become a trend. In some construction occasions, such as insulation layers and filling layers, ordinary concrete cannot be used due to its heavy weight and poor insulation effect. Lightweight concrete not only reduces the load on buildings and extends their service life, but also facilitates the recycling of building materials. In addition, the thermal insulation performance of concrete is particularly important for reducing the urban "heat island effect". The concrete currently used cannot fully combine lightweight and thermal insulation, and there is huge room for improvement.

[0004] Chinese patent application CN114349429A discloses a lightweight concrete, which includes the following raw materials in parts by weight: 350-420 parts of cement, 450-600 parts of multi-layer lightweight aggregate, 200-300 parts of fine aggregate, 300-500 parts of coarse aggregate, 18-23 parts of admixture, and 160-175 parts of water. The multi-layer lightweight aggregate is a composite material with aramid fiber as the core material, a polydopamine layer as the second outer layer, and an amino silicone oil modified silica particle layer as the outermost layer. The concrete has excellent compressive strength, flexural strength and low water absorption, but does not have good thermal insulation performance. In order to improve the thermal insulation performance of concrete, foam concrete is generally used in this field, but the compressive strength of foam concrete is poor. Summary of the invention

[0005] One object of the present invention is to provide a concrete with small deadweight and good thermal insulation performance in view of the above technical problems to be solved.

[0006] Another object of the present invention is to provide a method for preparing the above concrete.

[0007] In order to achieve the above invention objectives, the present invention provides a lightweight insulating concrete, which includes the following components by weight: 5-10 parts of cement, 5-8 parts of porous ceramics, 1-2 parts of diatomaceous earth, 5-8 parts of polyurethane particles, 2 parts of glass fiber, 1-2 parts of rubber latex, 3 parts of water, and 1-2 parts of admixture.

[0008] As a preferred embodiment, according to the lightweight insulating concrete of the present invention, the porous ceramic is granular, with a diameter of 10-30 mm, more preferably 20 mm.

[0009] As a preferred embodiment, according to the lightweight insulating concrete of the present invention, the diameter of the polyurethane particles is 5-15 mm, more preferably 10 mm.

[0010] As a preferred embodiment, according to the lightweight insulating concrete of the present invention, the length of the glass fiber is 0.3-0.8 mm, more preferably 0.6 mm.

[0011] As a preferred embodiment, according to the lightweight insulating concrete of the present invention, the rubber latex is styrene-butadiene latex, and more preferably consists of styrene and butadiene in a weight ratio of 30:70.

[0012] As a preferred embodiment, according to the lightweight insulating concrete of the present invention, the admixture contains 25% of water reducing agent and 3% of air entraining agent by weight.

[0013] In a second aspect of the present invention, a method for preparing the lightweight insulating concrete is provided, the method comprising the following steps:

[0014] S1. dispersing the glass fiber in the rubber latex to obtain a glass fiber dispersion;

[0015] S2. Stir the cement and porous ceramic, add the glass fiber dispersion and half of the water and half of the admixture;

[0016] S3. After stirring evenly, add diatomaceous earth and polyurethane particles to the above mixture, then add the remaining water and admixtures, continue to stir evenly, and obtain the lightweight insulating concrete.

[0017] The lightweight heat-insulating concrete of the present invention is added with glass fiber, which is first dispersed in rubber emulsion, so that it can be dispersed more evenly in the subsequent concrete preparation process. The mechanical strength of the porous ceramic and cement bonding interface is low, and the interface bonding strength of the two can be improved by adding glass fiber. In addition, the addition of glass fiber also helps to achieve a good heat-insulating effect.

[0018] Compared with the existing ordinary lightweight insulating concrete, the lightweight insulating concrete of the present invention adds glass fiber, porous ceramics, diatomaceous earth and polyurethane particles to cement in appropriate proportions. The raw material components work synergistically to make the prepared concrete have multiple advantages of low density, high strength and good thermal insulation, solve the shortcomings of heavy concrete and poor thermal insulation effect, can effectively reduce the load on buildings, reduce the burden on infrastructure, reduce the use of building materials, reduce construction costs, and has excellent thermal insulation capacity, can effectively reduce heat transfer, reduce the urban "heat island effect", meet the requirements of sustainable development, and enrich the use of concrete in special construction occasions. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with specific examples. It should be understood that the following examples are only used to illustrate the present invention, rather than to limit the scope of the present invention.

[0020] Unless otherwise specified, the raw material components used in the present invention are all raw material components available in the art through commercial sales channels.

[0021] Among the components of the following examples:

[0022] The cement is ordinary Portland cement.

[0023] The porous ceramic is granular alumina ceramic with a porosity of about 62.5%, an average pore size of 1 to 2 mm, and a diameter of 20 mm. The manufacturer is Lujiang County Jingshi Special Building Materials Co., Ltd.

[0024] The diameter of the polyurethane particles is 10 mm, and the manufacturer is Wen'an County Yingtong Environmental Protection Technology Co., Ltd.

[0025] The length of the glass fiber is 0.6mm, and the manufacturer is Shandong Tonghui Glass Fiber Co., Ltd.

[0026] The rubber latex is styrene butadiene latex (the weight ratio of styrene to butadiene is 30:70, and the solid content is 40%), and the manufacturer is Shandong Maofa Chemical Co., Ltd.

[0027] The admixture contains 25% polycarboxylic acid water-reducing agent, 3% fatty alcohol air-entraining agent, 20% collapse-preventing mother liquor, 0.5% defoaming agent, 2% dextrin, 3% sodium gluconate, and 46.5% water (by weight). The manufacturer is Guangdong Liuhe New Building Materials Co., Ltd.

[0028] Example 1

[0029] A lightweight heat-insulating concrete has the following raw material components: 10kg of cement, 5kg of porous ceramics, 2kg of diatomaceous earth, 5kg of polyurethane particles, 2kg of glass fiber, 1kg of rubber latex, 3kg of water, and 2kg of admixture.

[0030] Follow these steps to prepare lightweight insulating concrete:

[0031] 1. Dispersing glass fiber in rubber latex to obtain glass fiber dispersion;

[0032] 2. Mix the cement and porous ceramics evenly, add the above glass fiber dispersion, half of the water and half of the additives;

[0033] 3. After stirring evenly, add diatomaceous earth and polyurethane particles to the above mixture, then add the remaining water and admixtures, continue to stir evenly to obtain lightweight insulating concrete.

[0034] Example 2

[0035] A lightweight heat-insulating concrete has the following raw material components: 10kg of cement, 8kg of porous ceramics, 1kg of diatomaceous earth, 8kg of polyurethane particles, 2kg of glass fiber, 2kg of rubber latex, 3kg of water, and 2kg of admixture.

[0036] The preparation method of the lightweight insulating concrete is the same as that of Example 1.

[0037] Example 3

[0038] A light heat-insulating concrete has the following raw material components: 5kg of cement, 8kg of porous ceramics, 2kg of diatomaceous earth, 5kg of polyurethane particles, 2kg of glass fiber, 2kg of rubber latex, 3kg of water and 1kg of admixture.

[0039] The preparation method of the lightweight insulating concrete is the same as that of Example 1.

[0040] Comparative Example 1

[0041] A kind of concrete has the following raw material formula: 10kg of ordinary Portland cement, 6kg of fly ash, 13kg of sand, 18kg of stone, 1kg of admixture and 3kg of water.

[0042] Admixture formula: 20% naphthalene water reducer, 1% fatty alcohol air entraining agent, 25% collapse-preventing mother liquor, 0.5% defoaming agent, 3% white sugar, 2% sodium citrate, 48.5% water (by weight).

[0043] The preparation method is as follows: cement, fly ash, sand, stone and water are mixed evenly, then admixture is added, and mixing is continued to be evenly obtained to obtain concrete.

[0044] Comparative Example 2

[0045] A lightweight heat-insulating concrete, which differs from the formula of Example 1 in that it does not contain porous ceramics. The preparation method is the same as that of Example 1.

[0046] Comparative Example 3

[0047] A lightweight heat-insulating concrete, which differs from the formula of Example 1 in that it does not contain diatomaceous earth. The preparation method is the same as that of Example 1.

[0048] Comparative Example 4

[0049] A lightweight heat-insulating concrete, which differs from the formula of Example 1 in that it does not contain polyurethane particles. The preparation method is the same as that of Example 1.

[0050] Comparative Example 5

[0051] A lightweight heat-insulating concrete, which differs from the formula of Example 1 in that it does not contain glass fiber and rubber latex. The preparation method is the same as that of Example 1.

[0052] Concrete performance testing

[0053] The density, thermal conductivity, thermal insulation, compressive strength, flexural strength, flame retardancy and other properties of the concrete samples prepared in the above Examples 1-3 and Comparative Examples 1-5 were tested, and the test methods / standards used are as follows:

[0054] (1) Density: volume method.

[0055] (2) Water absorption: weighing method.

[0056] (3) Thermal conductivity: GB / T 37796-2019 Test method for thermal conductivity of insulating refractory materials.

[0057] (4) Thermal insulation rate: GB / T 37796-2019 Test method for thermal conductivity of insulating refractory materials.

[0058] (5) Compressive strength: GB / T50081-2019 "Standard for test methods for physical and mechanical properties of concrete".

[0059] (6) Flexural strength: GB / T50081-2019 "Standard for test methods for physical and mechanical properties of concrete".

[0060] (7) Flame retardant properties: GB / T8624-2012 "Classification of Combustion Performance of Building Materials and Products".

[0061] After testing, the performance results of the concrete samples of Examples 1-3 and Comparative Examples 1-5 are as follows:

[0062]

[0063] From the above results, it can be seen that the density of the lightweight insulating concrete of Examples 1-3 is 0.8-1.2 g / cm 3, thermal conductivity is 0.02-0.06W / (mK), thermal insulation rate is ≥92%, compressive strength can reach 15-20MPa, flexural strength can reach 5.0-6.0MPa, flame retardant performance can reach A2 level, and has excellent fireproof performance. Compared with the concrete of comparative examples 1-5, the lightweight insulating concrete of examples 1-3 has better performance and comprehensive performance.

Claims

1. A lightweight insulating concrete, characterized in that The composition includes the following components by weight: 5-10 parts of cement, 5-8 parts of porous ceramics, 1-2 parts of diatomaceous earth, 5-8 parts of polyurethane particles, 2 parts of glass fiber, 1-2 parts of rubber latex, 3 parts of water and 1-2 parts of admixture.

2. The lightweight insulating concrete according to claim 1, characterized in that: The porous ceramic is in granular form and has a diameter of 10-30 mm.

3. The lightweight insulating concrete according to claim 1, characterized in that: The polyurethane particles have a diameter of 5-15 mm.

4. The lightweight insulating concrete according to claim 1, characterized in that: The length of the glass fiber is 0.3-0.8 mm.

5. The lightweight insulating concrete according to claim 1, characterized in that: The rubber latex is styrene-butadiene latex.

6. The lightweight insulating concrete according to claim 1, characterized in that: The admixture contains 25% of a water reducing agent and 3% of an air entraining agent by weight.

7. A method for preparing the lightweight insulating concrete according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: S1. dispersing the glass fiber in the rubber latex to obtain a glass fiber dispersion; S2. Stir the cement and porous ceramic, add the glass fiber dispersion and half of the water and half of the admixture; S3. After stirring evenly, add diatomaceous earth and polyurethane particles to the above mixture, then add the remaining water and admixtures, continue to stir evenly, and obtain the lightweight insulating concrete.

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