Autoclaved aerated concrete wall masonry mortar and preparation method thereof

Abstract

The invention provides autoclaved aerated concrete wall masonry mortar and a preparation method thereof. The concrete wall masonry mortar is prepared from a cementing material, blended aggregate, fly ash and high-temperature-resistant cellulose ether, the cementing material comprises cement and an expanding agent; the blended aggregate comprises refined sand and thermal insulation fine aggregate, the thermal insulation fine aggregate comprises ceramic microbeads and vitrified microbeads, and the particle size of the thermal insulation fine aggregate is smaller than that of the refined sand; wherein in the masonry mortar, the proportion of the expanding agent is 4%-5%, the proportion of the refined sand is 70.5%-71.5%, the proportion of the ceramic microbeads is 1%-2%, the proportion of the vitrified microbeads is 1.5%-2%, the proportion of the fly ash is 1.5%-5.5%, and the proportion of the high-temperature-resistant cellulose ether is 0.012%-0.013%. The masonry mortar for the concrete wall, provided by the invention, is high in strength, small in mortar joint and good in adhesion.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to autoclaved aerated concrete wall masonry mortar and a preparation method thereof. Background Art

[0002] With the vigorous promotion of national energy conservation and emission reduction and wall material innovation, traditional clay brick masonry is being replaced by concrete hollow blocks, concrete bricks, autoclaved lime sand bricks, autoclaved fly ash bricks and autoclaved aerated concrete blocks. As one of the main substitutes for traditional clay brick masonry, autoclaved aerated concrete blocks are porous concrete products made of cement, lime, slag, sand, fly ash, gas generating agent, bubble stabilizer and regulator as the main raw materials, through grinding, metering and batching, mixing and pouring, gas expansion, static stopping, cutting, autoclaving and curing, finished product processing and other processes.

[0003] Autoclaved aerated concrete walls are constructed by laying out a number of autoclaved aerated concrete blocks with mortar. Currently, the more common problems with using traditional mortar for autoclaved aerated block construction include: excessively thick mortar joints, prominent problems with hot and cold bridges in mortar joints, late shrinkage cracking, leakage, and low masonry bonding strength. Thick mortar joints lead to high mortar consumption, and the masonry has strong water absorption, which causes the mortar to easily shrink and crack after water evaporation and full hydration, as well as low mortar bonding strength, which affects the promotion and use of autoclaved aerated concrete walls. Summary of the invention

[0004] Based on this, the object of the present invention is to provide an autoclaved aerated concrete wall masonry mortar and a preparation method thereof to solve the problems in the prior art.

[0005] In one aspect, the present invention provides an autoclaved aerated concrete wall masonry mortar, comprising: a cementitious material, an admixture aggregate, fly ash, and a high temperature resistant cellulose ether;

[0006] The cementitious material includes cement and an expansion agent;

[0007] The blended aggregate includes refined sand and thermal insulation fine aggregate, the thermal insulation fine aggregate includes ceramic microspheres and vitrified microspheres, and the particle size of the thermal insulation fine aggregate is smaller than that of the refined sand;

[0008] Among them, the proportion of expansion agent in the masonry mortar is 4%-5%, the proportion of refined sand is 70.5%-71.5%, the proportion of ceramic microspheres is 1%-2%, the proportion of vitrified microspheres is 1.5%-2%, the proportion of fly ash is 1.5%-5.5%, and the proportion of high temperature resistant cellulose ether is 0.012%-0.013%.

[0009] Preferably, the swelling agent is a UEA swelling agent.

[0010] Preferably, the particle size of the refined sand is 0.15 mm-0.3 mm.

[0011] Preferably, the particle size of the ceramic microbeads is less than 0.15 mm.

[0012] Preferably, the vitrified microspheres are inorganic vitrified microspheres, and the particle size of the vitrified microspheres is less than 0.15 mm.

[0013] Preferably, the high temperature resistant cellulose ether is hydroxypropyl methyl cellulose ether, and the gel temperature of the hydroxypropyl methyl cellulose ether is not more than 75°C.

[0014] Another aspect of the present invention provides a method for preparing the above-mentioned autoclaved aerated concrete wall masonry mortar, comprising:

[0015] Inspect and store cementitious materials, admixed aggregates, fly ash, and high-temperature resistant cellulose ether, wherein the cementitious materials include cement and expansion agent, the admixed aggregates include refined sand and thermal insulation fine aggregates, the thermal insulation fine aggregates include ceramic micro beads and vitrified micro beads, and the particle size of the thermal insulation fine aggregates is smaller than that of the refined sand;

[0016] Weigh various raw materials inspected and put into storage according to the preset ratio;

[0017] A certain amount of water is added to the mortar mixer, and the above raw materials are added after the mortar mixer is turned on for stirring and mixing;

[0018] The mortar after mixing is tested, qualified products are put into storage for use, and unqualified products are separated and processed.

[0019] Preferably, the water-cement ratio of water and raw materials put into the mortar mixer is 0.14:1-0.2:1.

[0020] Preferably, in the mortar mixer, the mixing time of water and raw materials is not less than 180s.

[0021] The beneficial effects of the present invention are as follows: the autoclaved aerated concrete wall masonry mortar provided by the present application; using refined sand, ceramic microspheres and vitrified microspheres as aggregates; making the mortar have a certain strength and good slurry spreading fluidity and ductility, having good auxiliary thermal insulation performance, and greatly reducing the dry density and wet apparent density of the mortar; adding an expansion agent into the mortar for compatibility, and adding the expansion agent into the mortar in a certain proportion, so that it produces a micro-expansion effect in the later curing process to offset the shape shrinkage change of the cement binder, thereby achieving the effect of stabilizing the volume of the mortar in the later stage; targeting the water absorption characteristics of the autoclaved aerated block brick Point, when designing the mortar for autoclaved aerated concrete wall masonry, adding high temperature resistant cellulose ether to the mortar is the technical key of this application. The high temperature resistant cellulose ether is hydroxypropyl methylcellulose ether. Adding a certain proportion of high-efficiency instant high temperature resistant modified cellulose ether can make the mortar quickly disperse into the paste in a short mixing time, making the mortar a colloidal viscous state, satisfying its water retention and viscosity increase function under high temperature, and continuously providing sufficient water retention effect for the mortar, so that it can be fully hydrated and solidified; solve the problems of conventional masonry mortar with too thick mortar joints, prominent cold and hot bridge problems in mortar joints, late shrinkage cracking, leakage, and low masonry bonding strength. .

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of a method for preparing a wafer handling arm provided by the present invention.

[0024] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] The invention provides an autoclaved aerated concrete wall masonry mortar, which is used for masonry of autoclaved aerated concrete product blocks. The autoclaved aerated concrete wall thin-layer masonry mortar is developed by reasonably designing the material mix ratio, adding fine aggregate, thermal insulation fine aggregate, expansion agent and high-temperature resistant cellulose ether, and the mortar can solve the problems of uniformity of strength and thermal insulation performance of the special masonry mortar, compatibility, generation of cold and hot bridges due to excessive thickness of traditional mortar joints, false powdering due to water loss of mortar in the early stage, and hardening and shrinkage of mortar in the later stage.

[0029] Specifically, the autoclaved aerated concrete wall masonry mortar includes: cementitious materials, admixture aggregates, fly ash, and high-temperature resistant cellulose ether; the cementitious materials include cement and expansion agents; the admixture aggregates include refined sand and thermal insulation fine aggregates, the thermal insulation fine aggregates include ceramic microspheres and vitrified microspheres, and the particle size of the thermal insulation fine aggregates is smaller than that of the refined sand.

[0030] Refined sand, ceramic microspheres and vitrified microspheres are used as aggregates, and the vitrified microspheres can be inorganic vitrified microspheres; they can ensure the aggregate blending ratio in the mortar, make the mortar have a certain strength, and have good slurry spreading fluidity and ductility, and can greatly reduce the mortar joints of the masonry body, so that the mortar has good auxiliary thermal insulation performance, and can greatly reduce the dry density and wet apparent density of the mortar, making the construction light and fast, and reducing the labor intensity of the construction workers. Since the particle size of the thermal insulation fine aggregate is smaller than that of the refined sand, the spreading fluidity of the mortar and the characteristics of the thin-layer masonry mortar joints are further consolidated and strengthened;

[0031] Furthermore, the basic cementitious material of the autoclaved aerated concrete wall masonry mortar of the present application is cement, and the cement can be M32.5 cement (composite Portland cement); the shrinkage and cracking of cement-based materials during later drying is their biggest material performance defect. The mortar is very prone to shrinkage and cracking after water evaporation and full hydration. In response to this, an expansion agent is added to the mortar for compatibility. The expansion agent can be a high-efficiency UEA expansion agent with good compatibility. It is added to the mortar in a certain proportion to produce a micro-expansion effect during the later curing process to offset the shrinkage changes in the shape of the cement binder, thereby achieving a volume stability effect of the mortar in the later stage.

[0032] Furthermore, due to the particularity of the water absorption characteristics of autoclaved aerated bricks, the moisture moistened in advance cannot penetrate into the interior of the bricks well. In addition, many autoclaved aerated bricks have a high temperature and a short cooling time when they are used on the construction site from the factory. Therefore, a double technical test is posed to the special mortar for masonry. On the one hand, it must meet the technical requirements of efficient and continuous water retention performance of this special masonry, and on the other hand, it must face the problems of mortar loss of adhesion, premature curing, false setting, etc. due to the high temperature of the masonry. In this regard, when designing the mortar for autoclaved aerated concrete wall masonry, adding high-temperature resistant cellulose ether to the mortar is the technical key of this application. The high-temperature resistant cellulose ether is hydroxypropyl methylcellulose ether. The addition of a certain proportion of high-efficiency, instant, high-temperature resistant modified cellulose ether can make the mortar quickly disperse into the paste in a short mixing time, making the mortar a colloidal viscous state. Due to its high gelation temperature, even if the brick cooling time is not sufficient, the addition of high-temperature resistant cellulose ether can also meet its water retention and viscosity-increasing effects under high temperature, and can continuously provide sufficient water retention effect for the mortar, so that it can be fully hydrated and solidified.

[0033] Example 1

[0034] The first embodiment of the present invention provides a method for preparing autoclaved aerated concrete wall masonry mortar, such as Figure 1 As shown, the preparation method comprises the following steps:

[0035] S10, inspect and store the cementitious materials, admixture aggregates, fly ash, and high temperature resistant cellulose ether;

[0036] Wherein, the cementitious material includes cement and an expansion agent, the admixture aggregate includes refined sand and thermal insulation fine aggregate, the thermal insulation fine aggregate includes ceramic microspheres and vitrified microspheres, and the particle size of the thermal insulation fine aggregate is smaller than that of the refined sand.

[0037] S20, weighing various raw materials inspected and put into storage according to a preset ratio;

[0038] S30, adding a certain amount of water into the mortar mixer, turning on the mortar mixer and adding the above raw materials to mix them;

[0039] S40, the mortar after mixing is tested, qualified products are put into storage for use, and unqualified products are separated and processed.

[0040] Optional, the mortar indicators refer to the implementation technical standards: Q / JXZK 004-2020 "Special thin-layer masonry mortar for autoclaved aerated concrete wall", GB / T 25181-2010 "Premixed mortar"; thermal conductivity refers to GB / T 10294 "Determination of steady-state thermal resistance and related properties of insulation materials - Guarded hot plate method", the technical indicators of the project product special thin-layer autoclaved aerated concrete wall masonry mortar are shown in Table 1;

[0041] Table 1

[0042] project Performance index requirements Appearance The product is uniform and free of lumps 28d compressive strength / Mpa ≥5 Water retention rate / % ≥99 14d tensile bond strength / Mpa ≥0.3 Shrinkage / % ≤0.2 <![CDATA[Apparent density, kg / m 3 > ≤1800 2h consistency loss rate, % ≤30 Thermal conductivity, W / mk ≤1

[0043] Specifically, in this embodiment, the expansion agent is UEA expansion agent, the particle size of refined sand is 0.15mm, the particle size of ceramic microspheres is 0.1mm, the vitrified microspheres are inorganic vitrified microspheres, the particle size of vitrified microspheres is 0.1mm, and the high temperature resistant cellulose ether is hydroxypropyl methylcellulose ether, and the gel temperature of hydroxypropyl methylcellulose ether is 70°C. The proportion of expansion agent in masonry mortar is 4%, the proportion of refined sand is 70.5%, the proportion of ceramic microspheres is 2%, the proportion of vitrified microspheres is 2%, the proportion of fly ash is 1.5%, the proportion of high temperature resistant cellulose ether is 0.013%, and the rest is M32.5 cement. The water-cement ratio of water and raw materials put into the mortar mixer is 0.2:1, and the mixing time of water and raw materials is 180s.

[0044] Example 2

[0045] The difference between this embodiment and embodiment 1 is that:

[0046] The particle size of refined sand is 0.2 mm, the particle size of ceramic microbeads is 0.12 mm, the gel temperature of hydroxypropyl methylcellulose ether is 60°C, the proportion of expansion agent in masonry mortar is 4.5%, the proportion of refined sand is 71%, the proportion of ceramic microbeads is 1.2%, the proportion of vitrified microbeads is 1.8%, the proportion of fly ash is 2.5%, the proportion of high temperature resistant cellulose ether is 0.0125%, and the rest is M32.5 cement. The water-cement ratio of water and raw materials put into the mortar mixer is 0.15:1, and the mixing time of water and raw materials is 190s.

[0047] Example 3

[0048] The difference between this embodiment and embodiment 1 is that:

[0049] The particle size of refined sand is 0.3mm, the particle size of ceramic microbeads is 0.15mm, the particle size of vitrified microbeads is 0.15mm, the gel temperature of hydroxypropyl methylcellulose ether is 70°C, the proportion of expansion agent in masonry mortar is 4.5%, the proportion of refined sand is 71.5%, the proportion of ceramic microbeads is 1%, the proportion of vitrified microbeads is 1.5%, the proportion of fly ash is 4.5%, the proportion of high temperature resistant cellulose ether is 0.012%, and the rest is M32.5 cement. The water-cement ratio of water and raw materials put into the mortar mixer is 0.14:1.

[0050] Example 4

[0051] The difference between this embodiment and embodiment 1 is that:

[0052] The particle size of refined sand is 0.25mm, the particle size of ceramic microspheres is 0.15mm, the particle size of vitrified microspheres is 0.1mm, and the gel temperature of hydroxypropyl methylcellulose ether is 75℃. Hydroxypropyl methylcellulose ether is in gel state below 75℃ and does not stick above 75℃. 75℃ can basically meet the temperature requirements for construction in high temperature weather in summer. The proportion of expansion agent in masonry mortar is 5%, the proportion of refined sand is 71%, the proportion of ceramic microspheres is 1.5%, the proportion of vitrified microspheres is 1.8%, the proportion of fly ash is 4.5%, the proportion of high temperature resistant cellulose ether is 0.012%, and the rest is M32.5 cement. The water-cement ratio of water and raw materials put into the mortar mixer is 0.18:1, and the mixing time of water and raw materials is 200s.

[0053] Example 5

[0054] The difference between this embodiment and embodiment 1 is that:

[0055] The proportion of expansion agent in masonry mortar is 4.5%, the proportion of refined sand is 71%, the proportion of ceramic microspheres is 1.5%, the proportion of vitrified microspheres is 2%, the proportion of fly ash is 5.5%, and the mixing time of water and raw materials is 205s.

[0056] Comparative Example 1

[0057] The difference between this reference example and Example 1 is that:

[0058] The particle size of refined sand is 0.35mm, the particle size of ceramic microspheres is 0.2mm, the particle size of vitrified microspheres is 0.2mm, the proportion of expansion agent in masonry mortar is 5%, the proportion of refined sand is 72%, the proportion of ceramic microspheres is 2.5%, the proportion of vitrified microspheres is 2.5%, the proportion of fly ash is 6%, the proportion of high temperature resistant cellulose ether is 0.014%, and the rest is M32.5 cement

[0059] Comparative Example 2

[0060] The difference between this reference example and Example 1 is that:

[0061] The particle size of refined sand is 0.1mm, the particle size of ceramic microbeads is 0.2mm, the particle size of vitrified microbeads is 0.2mm, the proportion of expansion agent in masonry mortar is 5%, the proportion of refined sand is 72%, the proportion of ceramic microbeads is 2.5%, the proportion of vitrified microbeads is 2.5%, the proportion of fly ash is 6%, the proportion of high temperature resistant cellulose ether is 0.014%, and the rest is M32.5 cement.

[0062] Comparative Example 1

[0063] This comparative example adopts existing ordinary cement masonry mortar for masonry.

[0064] Comparative Example 2

[0065] This comparative example adopts existing common lime masonry mortar for masonry.

[0066] Comparative Example 3

[0067] This comparative example adopts existing ordinary lime cement masonry mortar for masonry.

[0068] The test results are shown in Table 2.

[0069] Table 2

[0070]

[0071]

[0072] Table 3

[0073]

[0074] It can be seen from Tables 2 and 3 that the autoclaved aerated concrete wall masonry mortar Q / JXZK 004-2020 "Special thin layer masonry mortar for autoclaved aerated concrete wall" prepared in this application is thinner and has comprehensive performance in terms of water retention, bonding strength, volume stability and low shrinkage, auxiliary thermal insulation and energy saving.

[0075] In summary, the autoclaved aerated concrete wall masonry mortar provided by the present application uses refined sand, ceramic microspheres, and vitrified microspheres as aggregates; the mortar has a certain strength and good slurry spreading fluidity and ductility, and has good auxiliary thermal insulation performance, and can greatly reduce the dry density and wet apparent density of the mortar; an expansion agent is added to the mortar for compatibility, and the expansion agent is added to the mortar in a certain proportion, so that it produces a micro-expansion effect in the later curing process to offset the shape shrinkage change of the cement binder, thereby achieving a stable volume effect of the mortar in the later stage; in view of the water absorption characteristics of the autoclaved aerated block brick body, When designing autoclaved aerated concrete wall masonry mortar, adding high-temperature resistant cellulose ether into the mortar is the technical key of the present application. The high-temperature resistant cellulose ether is hydroxypropyl methylcellulose ether. The addition of a certain proportion of high-efficiency, instant, high-temperature resistant modified cellulose ether can make the mortar quickly disperse into the paste in a short mixing time, making the mortar into a colloidal viscous state, satisfying its water retention and viscosity-increasing effects under high temperatures, and continuously providing sufficient water retention effect for the mortar, so that it can be fully hydrated and solidified; solve the problems of conventional masonry mortar with too thick mortar joints, prominent problems of hot and cold bridges in mortar joints, late shrinkage cracking, leakage, and low masonry bonding strength.

[0076] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0077] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. An autoclaved aerated concrete wall masonry mortar, characterized in that: include: Cementitious materials, admixture aggregates, fly ash, high temperature resistant cellulose ether; The cementitious material includes cement and an expansion agent; The blended aggregate includes refined sand and thermal insulation fine aggregate, the thermal insulation fine aggregate includes ceramic microspheres and vitrified microspheres, and the particle size of the thermal insulation fine aggregate is smaller than that of the refined sand; Among them, the proportion of expansion agent in the masonry mortar is 4%-5%, the proportion of refined sand is 70.5%-71.5%, the proportion of ceramic microspheres is 1%-2%, the proportion of vitrified microspheres is 1.5%-2%, the proportion of fly ash is 1.5%-5.5%, and the proportion of high temperature resistant cellulose ether is 0.012%-0.013%.

2. The autoclaved aerated concrete wall masonry mortar according to claim 1, characterized in that: The expansion agent is a UEA expansion agent.

3. The autoclaved aerated concrete wall masonry mortar according to claim 1, characterized in that: The particle size of the refined sand is 0.15mm-0.3mm.

4. The autoclaved aerated concrete wall masonry mortar according to claim 1, characterized in that: The particle size of the ceramic microbeads is less than 0.15 mm.

5. The autoclaved aerated concrete wall masonry mortar according to claim 1, characterized in that: The vitrified microspheres are inorganic vitrified microspheres, and the particle size of the vitrified microspheres is less than 0.15 mm.

6. The autoclaved aerated concrete wall masonry mortar according to claim 1, characterized in that: The high temperature resistant cellulose ether is hydroxypropyl methyl cellulose ether, and the gel temperature of the hydroxypropyl methyl cellulose ether is not more than 75°C.

7. A method for preparing the autoclaved aerated concrete wall masonry mortar according to any one of claims 1 to 6, characterized in that: include: Inspect and store cementitious materials, admixed aggregates, fly ash, and high-temperature resistant cellulose ether, wherein the cementitious materials include cement and expansion agent, the admixed aggregates include refined sand and thermal insulation fine aggregates, the thermal insulation fine aggregates include ceramic micro beads and vitrified micro beads, and the particle size of the thermal insulation fine aggregates is smaller than that of the refined sand; Weigh various raw materials inspected and put into storage according to the preset ratio; A certain amount of water is added to the mortar mixer, and the above raw materials are added after the mortar mixer is turned on for stirring and mixing; The mortar after mixing is tested, qualified products are put into storage for use, and unqualified products are separated and processed.

8. The preparation method according to claim 7, characterized in that: The water-cement ratio of water and raw materials put into the mortar mixer is 0.14:1-0.2:

1.

9. The preparation method according to claim 7, characterized in that: In the mortar mixer, the mixing time of water and raw materials shall not be less than 180s.

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