Thermal insulation building wall light weight mortar

Abstract

The application discloses a light-weight mortar for thermal insulation building wall, and the mortar raw material comprises Portland cement, cement modifier, expanded perlite, fly ash, 4-4'-diphenyldimethyl dicarboxylate, modified composite fiber, lignin copolymer, vinyl acetate-vinyl versatate emulsion powder, butyl benzene emulsion, composite water reducing agent, methyl cellulose ether and expanding agent. The application focuses on improving the crack resistance, strengthening and toughening performance of the mortar. The added substances cooperate with each other to form a polymer film with a three-dimensional network structure in the light-weight anti-cracking finishing mortar, which improves the internal structure of the light-weight anti-cracking finishing mortar, improves the freeze-thaw resistance of the mortar, effectively reduces the compression ratio of the mortar, and makes the mortar exhibit good flexibility and crack resistance. The light-weight mortar for thermal insulation building wall has the advantages of high bonding strength, good water resistance, good flexibility, strong anti-shrinkage capacity, no shrinkage during hardening, good workability, small elastic modulus and certain thermal insulation effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building materials, in particular to a light-weight mortar for building wall with heat preservation and insulation. BACKGROUND

[0002] The main reason for the cracks in the coating finish of high-rise buildings is that the base layer under the coating is problematic. Compared with the block material pasting finish, the coating finish has strong integrity, but weak covering and extending properties, and the cracks in the base layer are easily reflected. It can be said that the building with coating finish has higher requirements for the stability and crack resistance of the base layer. The causes of the cracks in the light-weight block wall are various, and are related to the stability of the block material itself, the bonding performance between the wall material and the plastering layer, and the dry shrinkage performance of the plastering mortar. Ultimately, it lies in improving the performance of the mortar, such as improving the mechanical properties of the masonry mortar to improve the integrity of the block, enhancing the bonding performance between the wall base layer and the plastering layer to solve the phenomenon of easy hollowing and falling of the plastering layer, and enhancing the toughness of the plastering mortar to reduce the dry shrinkage cracks. The cement mortar will undergo plastic shrinkage and produce cracks before final setting, which is called plastic shrinkage crack. This is caused by the volume shrinkage of the mortar. During the process of hardening and forming strength of the mortar, the initial water and cement reaction forms crystalline, and the volume of this crystalline compound is smaller than that of the raw material, thus causing part of the volume shrinkage of the mortar. Another more important reason is the dry shrinkage caused by the evaporation of free water in the mortar. In the cement mortar, the unhydrated cement particles are suspended in water, and when the water begins to evaporate, the water between the cement particles begins to form a curved surface, generating suction. These shrinkage stresses exceed the tensile strength of the mortar matrix at some time, thus causing micro-cracks in the mortar. In engineering practice, due to the lack of effective anti-cracking measures, the inherent micro-cracks of the mortar develop into larger cracks under the action of internal and external stresses, so as to eventually form through capillary channels and cracks, which seriously affect the engineering quality. Research shows that most of the cracks are not related to the load, and the cracking factors such as plastic shrinkage, dry shrinkage and temperature change are the root causes of the cracking problem of the mortar.

[0003] Therefore, it is necessary to improve the performance of the mortar to solve the cracking problem of the mortar. SUMMARY

[0004] Therefore, it is necessary to improve the performance of the mortar to solve the cracking problem of the mortar.

[0005] The light-weight mortar for thermal insulation building wall of the present application comprises the following components in parts by weight: 50-60 parts of Portland cement, 5-10 parts of cement modifier, 20-30 parts of expanded perlite, 5-10 parts of fly ash, 1-3 parts of 4-4'-diphenyldicarboxylic acid dimethyl ester, 10-15 parts of modified composite fiber, 1-3 parts of lignin copolymer, 1-5 parts of vinyl acetate-vinyl versatate emulsion powder, 0.5-1.5 parts of butyl benzene emulsion, 1-5 parts of composite water reducing agent, 1-3 parts of methyl cellulose ether, and 1-3 parts of expanding agent.

[0006] Further, the cement modifier is prepared by the following method:

[0007] S1, mix tetrasodium pyrophosphate and deionized water, then sequentially add iron sulfate, glucose and potassium hydroxide, mix uniformly, then add polybutadiene emulsion and stir in a constant temperature water bath;

[0008] S2, continuously introduce nitrogen into step S2, then drop the mixture of styrene monomer and cumene hydroperoxide, finally add cumene hydroperoxide, and the cement modifier is prepared after the reaction is completed;

[0009] Further, the modified composite fiber is a mixture of loofah fiber, jute fiber and polyester fiber;

[0010] Further, the mass ratio of loofah fiber:jute fiber:polyester fiber is 3:2:1;

[0011] Further, the modified composite fiber is prepared by depositing catechol and N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane on the surface of the composite fiber;

[0012] Further, the lignin copolymer is prepared by grafting polymerization reaction of pre-hydrolyzed lignin, methacryloyloxyethyl trimethylammonium chloride and acrylamide with potassium persulfate initiator;

[0013] Further, the composite water reducing agent is a mixture of aminosulfonate water reducing agent and naphthalene-based high efficiency water reducing agent;

[0014] Further, the mass ratio of the aminosulfonate water reducing agent to the naphthalene-based high efficiency water reducing agent is 1:5;

[0015] Further, the expanding agent is SY-G expanding agent.

[0016] The building wall lightweight mortar with heat preservation and insulation of the present application focuses on improving the crack resistance, reinforcement and toughening performance of the mortar, the cooperation between the added substances forms a polymer film with three-dimensional network structure inside the lightweight anti-cracking finishing mortar, which improves the internal structure of the lightweight anti-cracking finishing mortar, not only improves the freeze-thaw resistance of the mortar, but also effectively reduces the pressure collapse ratio of the mortar, so that the mortar shows good flexibility and crack resistance. The building wall lightweight mortar with heat preservation and insulation of the present application has high bonding strength, good water resistance, good flexibility, strong anti-shrinkage ability, no shrinkage during hardening, good workability, small elastic modulus, and certain heat preservation and insulation effect. DETAILED DESCRIPTION

[0017] In order to better understand the present application, the following examples are further illustrations of the present application, but the content of the present application is not limited to the following examples.

[0018] In the examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified.

[0019] The thermal insulation building wall lightweight mortar of the embodiment comprises the following components by weight: 50-60 parts of Portland cement, 5-10 parts of cement modifier, 20-30 parts of expanded perlite, 5-10 parts of fly ash, 1-3 parts of 4-4'-diphenyldicarboxylic acid dimethyl ester, 10-15 parts of modified composite fiber, 1-3 parts of lignin copolymer, 1-5 parts of vinyl acetate-vinyl versatate emulsion powder, 0.5-1.5 parts of butyl benzene emulsion, 1-5 parts of composite water reducing agent, 1-3 parts of methyl cellulose ether, and 1-3 parts of expanding agent. The fly ash can increase the crack resistance of the mortar, but can reduce the wear resistance. Therefore, the fly ash and the modified composite fiber are used together to significantly improve the crack resistance of the cement mortar through adsorption stability, three-dimensional network structure bridging, fiber interface enhancement, and reinforcement crack resistance. The composite fiber can effectively prevent the development of cracks and improve the wear resistance of the mortar. The composite fiber can form a three-dimensional network support system in the mortar to reduce water separation on the surface of the mortar, improve the homogeneity, effectively prevent and inhibit the segregation tendency, and reduce or even completely prevent the generation of surface cracks of the mortar. At the same time, the composite fiber has a significant reinforcing effect on the initial hardened mortar to improve the tensile strength of the mortar and further inhibit the generation of cracks. The modified composite fiber can also reduce the shrinkage deformation of the matrix, enhance the ability of the mortar to resist temperature stress, improve the early crack resistance of the mortar, and improve the durability such as impermeability and freeze-thaw resistance. The vinyl acetate-vinyl versatate emulsion powder and the butyl benzene emulsion can improve the poor interface bonding between the fiber and the cement, so that the modified composite fiber, the vinyl acetate-vinyl versatate emulsion powder, the butyl benzene emulsion, and the expanding agent are used together to adjust the microstructure of the cement slurry, reduce the stress concentration, improve the interface bonding performance of the fiber-cement slurry, and improve the flexural strength, flexural pressure ratio, durability, and other properties of the cement mortar. At the same time, the 4-4'-diphenyldicarboxylic acid dimethyl ester, the fly ash, and the modified composite fiber can further improve the toughness and tensile strength of the mortar. The lignin copolymer, the modified composite fiber, and the expanding agent can improve the mechanical properties of the mortar and have heat resistance and insulation effects. The methyl cellulose ether and the cement modifier can improve the strength of the hardened mortar, improve the spreadability of the mortar, prolong the workable time, and have water retention, thickening, tackiness, and anti-sag effects.

[0020] In the embodiment, the cement modifier is prepared by the following method:

[0021] S1, mix tetrasodium pyrophosphate and deionized water, then add iron sulfate, glucose and potassium hydroxide in turn, mix well, then add polybutadiene emulsion into constant temperature water bath and stir;

[0022] S2, continuously introduce nitrogen into step S2, then drop the mixture of styrene monomer and cumene hydroperoxide, finally add cumene hydroperoxide, and the cement modifier is prepared after the reaction is completed; the cement modifier is used to improve the tightness between hydration products in the mortar, so that the structure is more compact, and the compressive strength and flexural strength of the mortar are improved.

[0023] In this embodiment, the modified composite fiber is a mixture of loofah fiber, jute fiber and polyester fiber; the mass ratio of loofah fiber: jute fiber: polyester fiber is 3:2:1; the modified composite fiber is prepared by depositing catechol and N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane on the surface of the composite fiber; the abundant pore structure of loofah fiber and jute fiber can improve the interfacial bonding strength between cement mortar and loofah fiber, and the modified loofah fiber, jute fiber and polyester fiber are distributed in the mortar in three-dimensional random distribution to form a three-dimensional crosslinked network structure, thereby improving the bonding performance and thermal stability of the mortar.

[0024] In this embodiment, the lignin copolymer is prepared by grafting polymerization reaction of pre-hydrolyzed lignin, methacryloyloxyethyl trimethyl ammonium chloride and acrylamide with potassium persulfate initiator; the lignin copolymer prepared in this way can improve the strength of the mortar, and at the same time, the mortar has high toughness.

[0025] In this embodiment, the composite water reducing agent is a mixture of aminosulfonate water reducing agent and naphthalene-based high efficiency water reducing agent; the mass ratio of the aminosulfonate water reducing agent to the naphthalene-based high efficiency water reducing agent is 1:5; the expanding agent is SY-G expanding agent.

[0026] Example one

[0027] The thermal insulation building wall light mortar of this embodiment comprises the following components by weight parts: Portland cement 50 parts, cement modifier 5 parts, expanded perlite 20 parts, fly ash 5 parts, 4-4'-dimethyl biphenyl dicarboxylate 1 part, modified composite fiber 10 parts, lignin copolymer 1 part, vinyl acetate-vinyl versatate emulsion powder 1 part, butyl benzene emulsion 0.5 part, composite water reducing agent 1 part, methyl cellulose ether 1 part, and expanding agent 1 part.

[0028] Example two

[0029] The thermal insulation building wall lightweight mortar of the embodiment comprises the following components in parts by weight: 60 parts of Portland cement, 10 parts of cement modifier, 30 parts of expanded perlite, 10 parts of fly ash, 3 parts of 4-4'-diphenyldicarboxylic acid dimethyl ester, 15 parts of modified composite fiber, 3 parts of lignin copolymer, 5 parts of vinyl acetate-vinyl versatate emulsion powder, 1.5 parts of butyl benzene emulsion, 5 parts of composite water reducing agent, 3 parts of methyl cellulose ether, and 3 parts of expanding agent.

[0030] Embodiment three

[0031] The thermal insulation building wall lightweight mortar of the embodiment comprises the following components in parts by weight: 50 parts of Portland cement, 10 parts of cement modifier, 20 parts of expanded perlite, 10 parts of fly ash, 1 part of 4-4'-diphenyldicarboxylic acid dimethyl ester, 15 parts of modified composite fiber, 1 part of lignin copolymer, 5 parts of vinyl acetate-vinyl versatate emulsion powder, 0.5 parts of butyl benzene emulsion, 5 parts of composite water reducing agent, 1 part of methyl cellulose ether, and 3 parts of expanding agent.

[0032] Embodiment four

[0033] The thermal insulation building wall lightweight mortar of the embodiment comprises the following components in parts by weight: 60 parts of Portland cement, 5 parts of cement modifier, 30 parts of expanded perlite, 5 parts of fly ash, 3 parts of 4-4'-diphenyldicarboxylic acid dimethyl ester, 10 parts of modified composite fiber, 3 parts of lignin copolymer, 1 part of vinyl acetate-vinyl versatate emulsion powder, 1.5 parts of butyl benzene emulsion, 1 part of composite water reducing agent, 3 parts of methyl cellulose ether, and 1 part of expanding agent.

[0034] Embodiment five

[0035] The thermal insulation building wall lightweight mortar of the embodiment comprises the following components in parts by weight: 52 parts of Portland cement, 8 parts of cement modifier, 23 parts of expanded perlite, 8 parts of fly ash, 2 parts of 4-4'-diphenyldicarboxylic acid dimethyl ester, 11 parts of modified composite fiber, 2.5 parts of lignin copolymer, 2 parts of vinyl acetate-vinyl versatate emulsion powder, 1.3 parts of butyl benzene emulsion, 2 parts of composite water reducing agent, 2 parts of methyl cellulose ether, and 2.2 parts of expanding agent.

[0036] Embodiment six

[0037] The thermal insulation building wall lightweight mortar of the embodiment comprises the following components in parts by weight: 55 parts of Portland cement, 7 parts of cement modifier, 25 parts of expanded perlite, 7 parts of fly ash, 2 parts of 4-4'-diphenyldicarboxylic acid dimethyl ester, 12 parts of modified composite fiber, 2 parts of lignin copolymer, 3 parts of vinyl acetate-vinyl versatate emulsion powder, 1 part of butyl benzene emulsion, 3 parts of composite water reducing agent, 2 parts of methyl cellulose ether, and 2 parts of expanding agent.

[0038] In the above embodiment, the cement modifier is prepared by the following method:

[0039] S1, tetrasodium pyrophosphate and deionized water are mixed, then iron sulfate, glucose and potassium hydroxide are added in sequence, mixed uniformly, then polybutadiene emulsion is added, and stirred in a constant temperature water bath;

[0040] S2, nitrogen is continuously introduced into step S2, then a mixture of styrene monomer and hydrogen peroxide is added dropwise, and finally hydrogen peroxide is added, and the cement modifier is prepared after the reaction is completed.

[0041] In the above embodiment, the modified composite fiber is a mixture of loofah fiber, jute fiber and polyester fiber; the mass ratio of loofah fiber: jute fiber: polyester fiber is 3:2:1; the modified composite fiber is prepared by the following method: catechol and N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane are deposited on the surface of the composite fiber; the lignin copolymer is prepared by grafting polymerization reaction of pre-hydrolyzed lignin, methacryloyloxyethyl trimethyl ammonium chloride and acrylamide with potassium persulfate initiator; the composite water reducing agent is a mixture of aminosulfonate water reducing agent and naphthalene-based high efficiency water reducing agent; the mass ratio of the aminosulfonate water reducing agent to the naphthalene-based high efficiency water reducing agent is 1:5; the expanding agent is SY-G expanding agent.

[0042] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A thermal insulation building wall lightweight mortar, characterized in that: The mortar raw material comprises the following components by weight parts: silicate cement 50-60 parts, cement modifier 5-10 parts, expanded perlite 20-30 parts, fly ash 5-10 parts, 4-4'-diphenyldicarboxylic acid dimethyl ester 1-3 parts, modified composite fiber 10-15 parts, lignin copolymer 1-3 parts, vinyl acetate-tert-vinyl acetate emulsion powder 1-5 parts, butyl benzene emulsion 0.5-1.5 parts, composite water reducing agent 1-5 parts, methyl cellulose ether 1-3 parts, and expanding agent 1-3 parts. S1, tetrasodium pyrophosphate and deionized water are mixed, then iron sulfate, glucose and potassium hydroxide are sequentially added, uniformly mixed, and then polybutadiene emulsion is added and stirred in a constant temperature water bath; S2, nitrogen is continuously introduced into step S1, then a mixture of styrene monomer and hydrogen peroxide cumene is added dropwise, and finally hydrogen peroxide cumene is added, and the cement modifier is prepared after the reaction is completed; The lignin copolymer is prepared by grafting polymerization reaction of pre-hydrolyzed lignin, methyl acryloyl ethyl trimethyl ammonium chloride and acrylamide with potassium persulfate initiator.

2. The heat insulated building wall lightweight mortar according to claim 1, characterized in that: The modified composite fiber is a mixture of loofah fiber, jute fiber and polyester fiber.

3. The heat insulated building wall lightweight mortar according to claim 2, characterized in that: The mass ratio of loofah fiber, jute fiber and polyester fiber is 3:2:

1.

4. The heat insulated building wall lightweight mortar according to claim 3, characterized in that: The modified composite fiber is prepared by depositing catechol and N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane on the surface of the composite fiber.

5. The heat insulated building wall lightweight mortar according to claim 1, characterized in that: The composite water reducing agent is a mixture of aminosulfonate water reducing agent and naphthalene-based high efficiency water reducing agent.

6. The heat insulated building wall lightweight mortar according to claim 5, characterized in that: The mass ratio of the aminosulfonate water reducing agent to the naphthalene-based high efficiency water reducing agent is 1:

5.

7. The heat insulated building wall lightweight mortar according to claim 1, characterized in that: The expanding agent is SY-G expanding agent.

8. The heat insulated building wall lightweight mortar according to claim 1, characterized in that: The mortar raw material comprises the following components by weight parts: silicate cement 50-60 parts, cement modifier 5-10 parts, expanded perlite 20-30 parts, fly ash 5-10 parts, 4-4'-diphenyldicarboxylic acid dimethyl ester 1-3 parts, modified composite fiber 10-15 parts, lignin copolymer 1-3 parts, vinyl acetate-tert-vinyl acetate emulsion powder 1-5 parts, butyl benzene emulsion 0.5-1.5 parts, composite water reducing agent 1-5 parts, methyl cellulose ether 1-3 parts, and expanding agent 1-3 parts.