Waterproof and anti-cracking two-in-one rendering coat mortar composition

Abstract

The invention provides a waterproof and anti-cracking two-in-one rendering coat mortar composition, and relates to the technical field of building coatings. The waterproof and anti-cracking two-in-one rendering coat mortar composition is prepared from the following raw material components in percentage by weight: more than or equal to 35 percent of cement, more than or equal to 2.5 percent of dispersible rubber powder, more than or equal to 50 percent of sand, more than or equal to 1 percent of a defoaming agent, 0.3 to 0.6 percent of anti-cracking fiber, 0.15 to 0.3 percent of a water reducing agent, 0.45 to 0.65 percent of a water repellent, 0.1 to 0.4 percent of cellulose and 0.3 to 0.6 percent of a thixotropic agent. Preferably, the raw material component can also comprise active kaolin. The rendering coat mortar composition disclosed by the invention has waterproof and anti-cracking properties, and a waterproof mortar working procedure in outer wall construction can be omitted.

Description

Technical Field

[0001] The invention belongs to the technical field of building coatings and relates to a waterproof and crack-resistant two-in-one plastering mortar composition. Background Art

[0002] With the implementation of the national mandatory standard for exterior wall waterproofing GB55030 on April 1, 2023, the exterior wall needs to be constructed with a waterproof layer. According to the traditional construction supporting process: base wall + waterproof mortar + bonding mortar + insulation board + anti-cracking plastering mortar + exterior wall putty + finishing layer, there are the following defects: (1) Some insulation boards need to be fixed with rivets during installation, which damages the waterproof layer and makes the waterproof function ineffective; (2) There is one more construction process, and the overall cost is significantly increased; (3) There is one more layer of waterproof mortar, the overall weight of the building increases, and the safety of the exterior wall insulation system is reduced.

[0003] Therefore, the above problems need to be solved urgently. Summary of the invention

[0004] If the waterproof function can be integrated into the anti-cracking plastering mortar product, it can not only save the construction process and corresponding materials of the waterproof mortar, greatly save costs, but also reduce the weight of the insulation system, ensure the safety of the system, and avoid damage to the waterproof layer during the installation of the insulation board. Based on this, the present invention provides a waterproof and anti-cracking two-in-one plastering mortar composition.

[0005] The technical solution of the present invention is as follows:

[0006] A waterproof and crack-resistant two-in-one plastering mortar composition, which comprises, by weight, 100% raw material components: cement ≥35%, dispersible rubber powder ≥2.5%, sand ≥50%, defoaming agent ≥1%, anti-cracking fiber 0.3-0.6%, water reducing agent 0.15-0.3%, water repellent 0.45-0.65%, cellulose 0.1-0.4%, and thixotropic agent 0.3-0.6%.

[0007] Preferably, the raw material components include: 35-42% cement, 2.5-4% dispersible rubber powder, 50-55% sand, 1-2% defoamer, 0.3-0.6% anti-cracking fiber, 0.15-0.3% water reducer, 0.45-0.65% water repellent, 0.1-0.4% cellulose, and 0.3-0.6% thixotropic agent.

[0008] Preferably, the weight percentage of the cement is not less than 38%.

[0009] Preferably, the weight percentage of the dispersible rubber powder is not less than 3%.

[0010] Preferably, the weight percentage of the defoaming agent is not less than 1.2%.

[0011] Preferably, the anti-cracking fiber is selected from polypropylene fiber.

[0012] Preferably, the water reducer is selected from polycarboxylate water reducer.

[0013] Preferably, the hydrophobic agent is selected from silane coupling agents.

[0014] Preferably, the raw material component further comprises activated kaolin, and the weight content of the activated kaolin is 1-3%.

[0015] More preferably, the activated kaolin is obtained by heating kaolin at 120-200° C. for 30 min-24 h.

[0016] The beneficial effects of the present invention are:

[0017] (1) The present invention improves the bonding strength and impermeability of the mortar block or insulation board by increasing the content of cement and glue powder in the plastering slurry without reducing the folding-compression ratio; improves the density of the plastering slurry by a high content of defoaming agent to improve the impermeability; reduces the water absorption of the plastering slurry and improves the impermeability by using functional additives such as hydrophobic agents. Through the above technical means, the two-in-one plastering mortar composition of the present invention simultaneously meets the requirements of the national standard GB55030 on waterproof mortar, the national standard GB / T29906-2013, and the industry standard JGT483-2013 on plastering mortar.

[0018] (2) The two-in-one plastering mortar composition of the present invention has good bonding strength, flexural strength, compressive strength, flexibility, etc. by adjusting the amount of cement, glue powder, etc. with a relatively high sand content. Compared with the traditional construction supporting process, the waterproof mortar process can be omitted, and the construction period and cost can be significantly reduced. The construction period can be shortened by 2-3 days from the original 5-8 days, and the cost can be reduced by 30-50% from the original 50-60 yuan / square meter, making it more competitive in the market. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0020] In order to achieve the waterproof and crack-resistant two-in-one performance of the plastering mortar and omit the waterproof mortar layer in the exterior wall construction process, the present invention provides a waterproof and crack-resistant two-in-one plastering mortar composition, which meets the requirements of the national standard GB55030 on waterproof mortar and the national standards GB / T29906-2013 and JGT483-2013 on plastering mortar while omitting the waterproof mortar layer in the exterior wall construction process. The technical scheme of the present invention is as follows: the waterproof and crack-resistant two-in-one plastering mortar composition is 100% by weight, and the raw material components include: cement ≥35%, dispersible rubber powder ≥2.5%, sand ≥50%, defoaming agent ≥1%, anti-cracking fiber 0.3-0.6%, water reducing agent 0.15-0.3%, water repellent 0.45-0.65%, cellulose 0.1-0.4%, and thixotropic agent 0.3-0.6%.

[0021] The plastering mortar composition of the present invention has the following characteristics in the design of raw material components: (1) Under a high sand content, by increasing the amount of cement and dispersible rubber powder, the bonding strength and anti-seepage performance with the mortar block or insulation board are improved without reducing the fold-to-compression ratio; however, the amount of dispersible rubber powder should not be too much, otherwise it will lead to the introduction of too many bubbles, making it difficult to defoam, and affecting the bonding strength, folding strength, etc.; (2) By increasing the amount of defoaming agent, the density of the plastering mortar is improved to improve the anti-seepage performance; however, the amount of defoaming agent should not be too much, otherwise it will be unfavorable for defoaming; (3) The water absorption and waterproof and anti-seepage performance of the plastering mortar are reduced by functional additives such as hydrophobic agents. Therefore, the plastering mortar composition of the present invention can achieve waterproof and crack resistance two-in-one, save the waterproof mortar process in the existing exterior wall construction process, save costs, and reduce the construction period. The cost can be reduced by 30-50%, and the construction period can be shortened by 2-3 days on the basis of the original 5-8 days.

[0022] Generally, the amount of defoamer (dimethyl silicone defoamer, etc.) in the plastering mortar composition will not exceed 0.8%, otherwise the defoamer is likely to be poorly dispersed, resulting in poor defoaming performance, and is not conducive to properties such as bonding strength and compressive strength. The plastering mortar composition of the present invention is optimized in formula, and a higher amount of defoamer is added to achieve better defoaming performance, improve the density of the plastering mortar to improve the anti-seepage performance, and will not affect other properties of the plastering mortar composition.

[0023] In a preferred embodiment of the present invention, the raw material components include: 35-42% cement, 2.5-4% dispersible rubber powder, 50-55% sand, 1-2% defoamer, 0.3-0.6% anti-cracking fiber, 0.15-0.3% water reducer, 0.45-0.65% water repellent, 0.1-0.4% cellulose, and 0.3-0.6% thixotropic agent. In the present invention, the weight content of cement can be any value among 35%, 35.5%, 36%, 36.5%, 37%, 37.5%, 38%, 38.5%, 39%, 39.5%, 40%, 40.5%, 41%, 41.5%, 42% etc. or any value in between, without special restriction; the weight content of dispersible rubber powder can be any value among 2.5%, 2.7%, 2.8%, 3%, 3.1%, 3.2%, 3.3%, 3.5%, 3.7%, 3.8%, 4.0% etc. or any value in between, without special restriction; the weight content of defoamer can be any value among 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2% etc. or any value in between, without special restriction.

[0024] In a preferred embodiment of the present invention, the weight percentage of cement is not less than 38%. For example, the weight percentage of cement can be any value among 38%, 38.5%, 39%, 39.5%, 40%, 40.5%, 41%, 41.5%, 42%, etc. or any value in between, without special limitation. The grade of cement of the present invention is not particularly limited, and can be Portland cement and / or sulphoaluminate cement, such as Portland cement with strength grades of 42.5, 42.5R, 52.5, 52.5R, 62.5, 62.5R, etc., which can be directly purchased from the market.

[0025] In a preferred embodiment of the present invention, the weight percentage of the dispersible rubber powder is not less than 3%. For example, the weight percentage of the dispersible rubber powder can be any value among 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, etc. or any value in between, without special limitation. The dispersible rubber powder of the present invention can be directly purchased from the market.

[0026] In a preferred embodiment of the present invention, the weight percentage of the defoamer is not less than 1.2%. For example, the weight percentage of the defoamer can be any value among 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, etc. or any value in between, without special limitation. In the present invention, the defoamer can be a dimethyl silicone oil defoamer, or a dimethyl silicone oil defoamer loaded with white carbon black, which has the characteristics of good defoaming performance and avoiding microbubble formation, and can be directly purchased from the market.

[0027] In a preferred embodiment of the present invention, the anti-cracking fiber is selected from polypropylene fiber. The polypropylene anti-cracking fiber has good anti-cracking performance, a tensile strength of not less than 5000MPa, an elastic modulus of not less than 3850MPa, a diameter of 15-50μm, and a length of 3-60μm. It can improve the anti-cracking performance in the plastering mortar composition, and the polypropylene anti-cracking fiber can be directly purchased from the market. In the present invention, after the optimization of each raw material component, a higher flexural strength, compressive strength, flexibility, compression ratio, etc. can be achieved at a low content of polypropylene anti-cracking fiber, and a better anti-cracking performance can be achieved. If the amount of polypropylene anti-cracking fiber is too much, the porosity of the plastering mortar will increase and the performance of the plastering mortar will decrease, such as the density, impermeability, compressive strength, etc. will all decrease. The amount of polypropylene anti-cracking fiber used in the present invention is relatively low, but due to the careful adjustment and synergistic effect of each raw material component in the plastering mortar composition, it still has good mechanical strength and good anti-cracking performance.

[0028] In a preferred embodiment of the present invention, the water reducing agent is selected from polycarboxylic acid water reducing agent. Polycarboxylic acid water reducing agent has the characteristics of low dosage, good slump retention, low paste shrinkage rate, etc., and can be directly purchased from the market.

[0029] In a preferred embodiment of the present invention, the water repellent is selected from a silane coupling agent, and the addition of the water repellent can significantly improve the waterproof performance of the plastering mortar. For example, the silane coupling agent can be isobutyltrimethoxysilane, isobutyltriethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, etc.

[0030] In a preferred embodiment of the present invention, the raw material components further include activated kaolin, and the weight content of the activated kaolin is 1-3%. The activated kaolin is further added to the plastering mortar of the present invention, which can further improve the performance of the plastering mortar, especially the tensile strength and flexural strength, compared with the unactivated kaolin. In the present invention, the average particle size of kaolin can be 1-50 μm, and the weight content of the activated kaolin can be any value among 1%, 1.5%, 2%, 2.5%, 3%, etc. or any value in between, without special restrictions.

[0031] In a more preferred embodiment of the present invention, the activated kaolin is obtained by heating kaolin at 120-200° C. for 30 min-24 h. Activating kaolin by heating is a relatively simple process and does not require post-treatment.

[0032] In the present invention, the cellulose is not particularly limited, and may be carboxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, etc.; the thixotropic agent is not particularly limited, and may be starch ether, bentonite, etc.

[0033] There is no particular limitation on the preparation method of the waterproof and crack-resistant two-in-one plastering mortar composition of the present invention, and the preparation method can be carried out according to a conventional method, such as mixing the raw material components and stirring to disperse them uniformly.

[0034] The technical solution of the present invention is further described and illustrated according to various embodiments below. Unless otherwise specified, the parts described in the following embodiments are parts by weight.

[0035] Example 1

[0036] The waterproof and crack-resistant two-in-one plastering mortar composition, based on 100% weight, the raw material components are 41% P.I42.5 silicate cement, 3.5% dispersible rubber powder, 52.05% sand (particle size 0.2-2mm), 1.5% dimethyl silicone defoaming agent, 0.4% polypropylene anti-cracking fiber, 0.2% polycarboxylic acid water reducer, 0.55% isobutyl triethoxy silane, 0.3% hydroxypropyl cellulose, and 0.5% bentonite thixotropic agent.

[0037] The above raw material components are mixed and stirred to be evenly dispersed to obtain a waterproof and crack-resistant two-in-one plastering mortar composition.

[0038] Example 2

[0039] The difference between this embodiment and embodiment 1 is that the cement is adjusted from 41% to 41.5%, and the dispersible rubber powder is adjusted from 3.5% to 3%. The other steps remain unchanged.

[0040] Example 3

[0041] The difference between this embodiment and embodiment 1 is that the cement is adjusted from 41% to 40.5%, and the dispersible rubber powder is adjusted from 3.5% to 4%. The other steps remain unchanged.

[0042] Comparative Example 1

[0043] The difference between this comparative example and Example 1 is that the cement is adjusted from 41% to 42.5%, and the dispersible rubber powder is adjusted from 3.5% to 2%. The other steps remain unchanged.

[0044] Comparative Example 2

[0045] The difference between this comparative example and Example 1 is that the cement is adjusted from 41% to 40%, and the dispersible rubber powder is adjusted from 3.5% to 4.5%. The other steps remain unchanged.

[0046] Comparative Example 3

[0047] The difference between this comparative example and Example 1 is that the cement is adjusted from 41% to 40.4%, and the polypropylene anti-cracking fiber is adjusted from 0.4% to 1%. The other steps remain unchanged.

[0048] Performance Testing

[0049] The test was conducted in accordance with the provisions of national standard GB55030, national standard GB / T29906-2013 and industry standard JGT483-2013. The results are shown in Table 1 below.

[0050] Table 1

[0051]

[0052]

[0053] From the above data results, it can be seen that the amount of dispersible rubber powder in the plastering mortar of the present invention is too low or too high, which cannot meet the requirements and will affect the anti-permeability and mechanical properties of the plastering mortar. Compared with the plastering mortars of Examples 1-3, the plastering mortar of Comparative Example 3 has more obvious bubbles inside after curing, indicating that adding too much polypropylene anti-cracking fiber will make it difficult to eliminate bubbles, affecting the anti-permeability, bonding strength, flexural strength, compressive strength and other properties.

[0054] Example 4

[0055] The waterproof and crack-resistant two-in-one plastering mortar composition, based on 100% weight, the raw material components are 40.5% P.I42.5 silicate cement, 3.8% dispersible rubber powder, 52% sand (particle size 0.2-2mm), 1.8% dimethyl silicone defoamer, 0.4% polypropylene anti-cracking fiber, 0.2% polycarboxylic acid water reducer, 0.5% isobutyl triethoxy silane, 0.3% hydroxypropyl cellulose, and 0.5% bentonite thixotropic agent.

[0056] The above raw material components are mixed and stirred to be evenly dispersed to obtain a waterproof and crack-resistant two-in-one plastering mortar composition.

[0057] Example 5

[0058] The difference between this embodiment and embodiment 6 is that the dimethyl silicone oil defoamer is adjusted from 1.8% to 1.3%, and the cement is adjusted from 40.5% to 41.1%. The other steps remain unchanged.

[0059] Example 6

[0060] The difference between this embodiment and embodiment 6 is that the dimethyl silicone oil defoamer is adjusted from 1.8% to 1.0%, and the cement is adjusted from 40.5% to 41.3%. The other steps remain unchanged.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 6 is that the dimethyl silicone oil defoamer is adjusted from 1.8% to 0.8%, and the cement is adjusted from 40.5% to 41.5%. The other steps remain unchanged.

[0063] Comparative Example 5

[0064] The difference between this comparative example and Example 6 is that the dimethyl silicone oil defoamer is adjusted from 1.8% to 2.3%, and the cement is adjusted from 40.5% to 40%. The other steps remain unchanged.

[0065] The performance results are shown in Table 2 below.

[0066] Table 2

[0067]

[0068]

[0069] It can be seen from the data in Table 2 above that the content of the defoaming agent in the plastering mortar of the present invention is not suitable if it is too high or too low, especially affecting the anti-seepage performance, which may be related to the excessively high bubble content after the mortar is cured due to insufficient defoaming performance.

[0070] Example 7

[0071] The waterproof and crack-resistant two-in-one plastering mortar composition, based on 100% weight, the raw material components are 41.1% P.I42.5 silicate cement, 3.2% dispersible rubber powder, 52.45% sand (particle size 0.2-2mm), 1.3% dimethyl silicone defoaming agent, 0.5% polypropylene anti-cracking fiber, 0.25% polycarboxylic acid water reducer, 0.5% isooctyltriethoxysilane, 0.3% hydroxypropyl cellulose, and 0.4% bentonite thixotropic agent.

[0072] Example 8

[0073] The difference between this embodiment and embodiment 7 is that the sand content is adjusted from 52.45% to 51.45%, and 1% of common kaolin (average particle size 20 μm) is added to the raw material component. The other steps remain unchanged.

[0074] Example 9

[0075] The difference between this embodiment and embodiment 7 is that the sand content is adjusted from 52.45% to 51.45%, and 1% of active kaolin (average particle size 20 μm) is added to the raw material component. The other steps remain unchanged.

[0076] The activated kaolin is obtained by heating kaolin at 160°C for 4 hours.

[0077] Example 10

[0078] The difference between this embodiment and embodiment 9 is that the sand is adjusted from 51.45% to 50.45%, and the activated kaolin is adjusted from 1% to 2%. The other steps remain unchanged.

[0079] The performance results are shown in Table 3 below.

[0080] Table 3

[0081]

[0082]

[0083] It can be seen from the data in Table 3 that further adding activated kaolin to the plastering mortar of the present invention can improve the flexural strength and compressive strength, and also has a role in improving flexibility.

[0084] As described above, the basic principles, main features and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited by the above embodiments, which are only preferred embodiments of the present invention and cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the scope of the present invention and the content of the specification should still be within the scope of the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents.

Claims

1. A waterproof and crack-resistant two-in-one plastering mortar composition, characterized in that: Based on 100% by weight, the raw material components include: cement ≥35%, dispersible rubber powder ≥2.5%, sand ≥50%, defoaming agent ≥1%, anti-cracking fiber 0.3-0.6%, water reducing agent 0.15-0.3%, water repellent 0.45-0.65%, cellulose 0.1-0.4%, and thixotropic agent 0.3-0.6%.

2. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The raw material components include: 35-42% cement, 2.5-4% dispersible rubber powder, 50-55% sand, 1-2% defoamer, 0.3-0.6% anti-cracking fiber, 0.15-0.3% water reducing agent, 0.45-0.65% water repellent, 0.1-0.4% cellulose and 0.3-0.6% thixotropic agent.

3. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The weight percentage of the cement is not less than 38%.

4. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The weight percentage of the dispersible rubber powder is not less than 3%.

5. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The weight percentage of the defoaming agent is not less than 1.2%.

6. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The anti-cracking fiber is selected from polypropylene fiber.

7. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The water reducer is selected from polycarboxylate water reducer.

8. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The water repellent agent is selected from silane coupling agents.

9. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 1, characterized in that: The raw material components further comprise activated kaolin, and the weight content of the activated kaolin is 1-3%.

10. The waterproof and crack-resistant two-in-one plastering mortar composition according to claim 9, characterized in that: The activated kaolin is obtained by heating kaolin at 120-200° C. for 30 min-24 h.

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