Rheological stabilizer for self-leveling mortar and application thereof

Abstract

The present application relates to the technical field of building materials, and particularly relates to a rheological stabilizer for self-leveling mortar, which comprises the following raw materials: low-viscosity cellulose ether, microbial thickening agent, powder dispersant, high-molecular lubricant and filler; the rheological stabilizer for self-leveling mortar is obtained by mixing the raw materials in proportion and then uniformly mixing the raw materials by high-speed stirring equipment; and the rheological stabilizer for self-leveling mortar is mixed into cement-based self-leveling mortar or gypsum-based self-leveling mortar in a certain amount. The rheological stabilizer for self-leveling mortar is mixed into self-leveling mortar, which improves the dispersion effect of self-leveling mortar, and after stirring, no agglomeration occurs, the slurry lubricity is improved, the pumping effect is improved, the phenomena such as aggregate deposition and slurry adsorption on the pipe wall are reduced, the equipment cleaning time is reduced, and the construction efficiency is improved; the raw materials used are all conventional chemical raw materials, the quality of the raw materials is stable and controllable, the preparation method is simple, the production can be operated in a water flow mode, the control difficulty is small, and therefore the product quality of the rheological stabilizer for self-leveling mortar is stable and controllable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, and particularly relates to a rheological stabilizer for self-leveling mortar and application thereof. BACKGROUND

[0002] As an important part of a building, the quality of a ground is increasingly concerned by people. The self-leveling mortar is a new type of environment-friendly ground decoration material, which is prepared by uniformly mixing cementitious materials, fine aggregates and admixtures, and then stirring with water, and flowing by self-gravity, and is specially used for leveling ground. The self-leveling mortar has the following advantages: (1) high flatness, the self-leveling mortar can be once leveled, and does not need secondary leveling; (2) reducing cracking risk: the self-leveling mortar has good volume stability due to the micro-expansion property of the cementitious system; (3) high construction efficiency: the operation is convenient and efficient, and the self-leveling mortar can be constructed by using a pump. The self-leveling mortar is widely used for ground laying and fine leveling in industrial plants, residential buildings, supermarkets, stadiums, logistics warehouses, underground garages, office buildings, waiting rooms and hospitals. The self-leveling mortar usually takes gypsum or cement as a matrix, and the gypsum-based self-leveling mortar becomes a research and application hotspot in recent years because it is more suitable for leveling and covering layer of a ground heating system.

[0003] The self-leveling mortar belongs to high-fluidity mortar, and has high requirements for the construction process. If the control is improper, quality problems such as delamination, bleeding and surface whitening are easily caused. The common problems include: (1) water quantity sensitivity: the self-leveling mortar has high fluidity by adding superplasticizer and the like, and is sensitive to water quantity. In the construction process, if the water quantity slightly exceeds the specified water quantity of the self-leveling mortar, the self-leveling mortar is prone to delamination, bleeding and sinking, which seriously affects the effect and engineering quality after construction; (2) a large number of bubbles: a large number of bubbles are generated in the stirring process of the self-leveling mortar, and the bubbles are not easy to eliminate, which is mainly caused by the too large viscosity of the slurry; (3) poor leveling property: the self-leveling mortar loses too much fluidity in the construction process after stirring, which leads to the failure of leveling; (4) local protrusions: the ground after construction has small lumps protruding, which is mainly caused by the poor dispersibility of the self-leveling mortar powder after adding water, and the agglomeration of the stirred slurry; (5) low pumping efficiency: the main performances are that the aggregate deposition of the pumping equipment causes the blockage of the machine and pipeline, and the slurry is viscous and adsorbed to the pipeline wall, and the cleaning of the equipment is time-consuming and laborious.

[0004] At present, the state of mortar is mainly improved by adding thickening agent, and common materials include cellulose ether, starch ether, magnesium aluminum silicate, etc. The cellulose ether mainly increases the viscosity of the slurry, reduces the segregation of aggregates and surface bleeding, and the low dosage has no obvious improvement effect, the high dosage will cause the slurry to be thick and viscous, bubbles are not easy to eliminate, and the effect of improving the water consumption sensitivity is poor; the organic thixotropic agent such as starch ether has obvious effect on surface bleeding, but the slurry flowability loss is large, and the actual application is less; the inorganic thixotropic agent such as magnesium aluminum silicate needs to be fully stirred to play the effect, and the stirring effect in actual engineering construction is difficult to achieve the design target, and the influence on the slurry flowability is also large. In summary, the single material is difficult to systematically improve the common problems in the application of self-leveling mortar, such as water consumption sensitivity, slow state, thick slurry, low pumping efficiency, etc. SUMMARY

[0005] The technical problem solved by the present application is: in order to overcome the deficiencies in the prior art, a rheological stabilizer for self-leveling mortar and its application are provided, which is mainly used for cement self-leveling mortar and gypsum self-leveling mortar, and is a functional additive for improving the dispersion effect of self-leveling mortar, improving the aggregate suspension, and reducing bleeding and water consumption sensitivity.

[0006] The technical scheme adopted by the present application is: a rheological stabilizer for self-leveling mortar, which comprises the following raw materials in parts by mass:

[0007]

[0008] Further, the low-viscosity cellulose ether is one of hydroxypropyl cellulose and hydroxyethyl cellulose, and the viscosity is less than 4000 mPa·s.

[0009] Further, the microbial thickening agent is one of xanthan gum, gellan gum and Wenlon gum.

[0010] Further, the powder dispersant is one of sodium polyphosphate, sodium tripolyphosphate and sodium butyl naphthalene sulfonate.

[0011] Further, the high molecular lubricant is polyethylene oxide.

[0012] Further, the filler is one of wollastonite powder and talc powder.

[0013] The rheological stabilizer for self-leveling mortar is proportioned, mixed uniformly by a high-speed stirring equipment, and packaged to form a product.

[0014] The application of the rheological stabilizer for self-leveling mortar is as follows:

[0015] The rheological stabilizer for self-leveling mortar is applied to produce cement-based self-leveling mortar, and the mixing amount of the rheological stabilizer for self-leveling mortar is 0.06-0.10% of the total weight of the cement-based self-leveling mortar;

[0016] The rheological stabilizer for self-leveling mortar is applied to produce cement-based self-leveling mortar, and the mixing amount of the rheological stabilizer for self-leveling mortar is 0.06-0.10% of the total weight of the cement-based self-leveling mortar;

[0017] The produced self-leveling mortar has the characteristics of low water sensitivity, good anti-segregation and bleeding effect, easy dispersion and lubrication in pumping.

[0018] The rheological stabilizer of the present application is composed of low-viscosity cellulose ether, microbial thickening agent, powder dispersant, high-molecular lubricant and filler.

[0019] Firstly, the low-viscosity cellulose ether mainly thickens through hydration and molecular entanglement, and has a rapid thickening effect, but a high mixing amount of the low-viscosity cellulose ether will increase the viscosity of the slurry, and the microbial thickening agent forms a three-dimensional network structure for water molecules through the cross-linking of its molecular chain, so that the fluidity of the liquid is reduced, the structure is stable, the slurry has good thixotropy and low viscosity, but a high mixing amount of the microbial thickening agent will cause a large loss of fluidity, and the combination of the two can make the best of both worlds, so that the self-leveling mortar can form a stable flowing slurry at a lower viscosity, prevent aggregate sinking, reduce bleeding and water sensitivity;

[0020] Secondly, the powder dispersant and high-molecular lubricant are added to improve the rheological properties of the slurry, so that the self-leveling mortar is easy to disperse and fully lubricated, the phenomena such as aggregate deposition and slurry adsorption on the pipe wall during pumping construction of the self-leveling mortar are reduced, the construction efficiency is improved, the powder dispersant can also reduce the solid-liquid interface energy, improve the dispersion effect of the self-leveling mortar, shorten the mixing time, improve the fluidity, and reduce the negative impact of the microbial thickening agent on the fluidity;

[0021] Finally, the low-viscosity cellulose ether, microbial thickening agent, powder dispersant and high-molecular lubricant have poor fluidity and are not easy to disperse uniformly during production, and the addition of the filler can improve the fluidity, help the uniform mixing during production, and obviously improve the storage stability of the product, so that the caking during long-term storage can be avoided.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] (1) The raw materials used in the present application are all conventional chemical raw materials, the quality of the raw materials is stable and controllable, the preparation method is simple, the production can be carried out in a water flow mode, and the control difficulty is small, so the quality of the rheological stabilizer for self-leveling mortar formed is stable and controllable.

[0024] (2) The rheological stabilizer for self-leveling mortar prepared by the present application improves the water sensitivity of self-leveling mortar and reduces the loss of flow rate over time through the synergistic effect of the components. Based on the standard water content, the water content is increased by 3-5% of the powder ratio, the aggregate does not sink to the bottom, there is no bleeding on the surface, and the density difference between the upper and lower layers is less than 20 kg / m 3 , the difference between the initial flow rate and the 30min flow rate of the prepared self-leveling mortar is less than 5mm.

[0025] (3) The rheological stabilizer produced by the present application is incorporated into self-leveling to improve the dispersion effect of self-leveling mortar, there is no agglomeration after stirring, the lubricity of the slurry is improved, the pumping effect is improved, the phenomena such as aggregate deposition and slurry adsorption on the pipe wall are reduced, the equipment cleaning time is shortened, and the construction efficiency is improved. DETAILED DESCRIPTION

[0026] The embodiments of the present application are described in detail below, the embodiments are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following embodiments.

[0027] Example 1

[0028] The following mass parts of raw materials: hydroxypropyl cellulose 15.0 parts, warm glue 13.0 parts, sodium polyphosphate 17.0 parts, polyethylene oxide 25.0 parts, and wollastonite powder 30.0 parts are proportioned and mixed uniformly in a high-speed stirring equipment to obtain a rheological stabilizer for self-leveling mortar.

[0029] Example 2

[0030] The following mass parts of raw materials: hydroxypropyl cellulose 20.0 parts, warm glue 10.0 parts, sodium polyphosphate 24.0 parts, polyethylene oxide 20.0 parts, and wollastonite powder 26.0 parts are proportioned and mixed uniformly in a high-speed stirring equipment to obtain a rheological stabilizer for self-leveling mortar.

[0031] Example 3

[0032] The following mass parts of raw materials: hydroxypropyl cellulose 17.0 parts, warm glue 12.0 parts, sodium polyphosphate 20.0 parts, polyethylene oxide 22.0 parts, and wollastonite powder 29.0 parts are proportioned and mixed uniformly in a high-speed stirring equipment to obtain a rheological stabilizer for self-leveling mortar.

[0033] Example 4

[0034] The difference from Example 3 is that: hydroxyethyl cellulose 17.0 parts, gellan gum 12.0 parts, and sodium tripolyphosphate 20.0 parts.

[0035] Example 5

[0036] The difference from Example 3 is that hydroxyethyl cellulose 17.0 parts, xanthan gum 12.0 parts, sodium butylnaphthalene sulfonate 20.0 parts.

[0037] Comparative Example 1

[0038] The difference from Example 1 is that hydroxypropyl cellulose 10.0 parts, Warm gum 18.0 parts,

[0039] Comparative Example 2

[0040] The difference from Example 1 is that hydroxypropyl cellulose 25.0 parts, Warm gum 3.0 parts.

[0041] Comparative Example 3

[0042] The difference from Example 2 is that sodium polyphosphate 12.0 parts, polyethylene oxide 30.0 parts.

[0043] Comparative Example 4

[0044] The difference from Example 2 is that sodium polyphosphate 30.0 parts, polyethylene oxide 12.0 parts.

[0045] In order to better compare the anti-layering effect of the examples of the present application and commonly used thickeners, commonly used cellulose ethers, starch ethers, magnesium aluminum silicate, etc. are used for comparison, and performance tests are carried out.

[0046] Table 1 Performance table of cement-based self-leveling mortar prepared by the examples, comparative examples and comparative samples

[0047]

[0048] Note:

[0049] ①The dosage of rheological stabilizer and thickener is the best dosage confirmed by test, and the dosage of the examples is controlled within the range specified in the patent.

[0050] ②The uniform dispersion time is the time for uniform stirring without agglomeration in the slow stirring of the self-leveling mortar mixer.

[0051] ③In order to achieve obvious comparison effect, the surface bleeding and the test water amount of the difference between the upper and lower layers of wet bulk density after 60 min are increased by 3-5% of the water amount based on the standard water amount.

[0052] Table 2 Performance table of gypsum-based self-leveling mortar prepared by the examples, comparative examples and comparative samples

[0053]

[0054] Note:

[0055] ①The dosage of rheological stabilizer and thickener is the best dosage confirmed by test, and the dosage of the examples is controlled within the range specified in the patent.

[0056] ②Dispersing uniform time to self-leveling mortar mixer slow stirring uniform without agglomeration time.

[0057] ③To achieve a clear contrast effect, surface bleeding, 60 min wet density difference between the upper and lower layers of the test water, the standard water consumption, increase the proportion of 3-5% of the water consumption of the powder.

[0058] From the data of example 1-5, the rheological stabilizer for self-leveling mortar prepared by the present application can improve the dispersion effect of self-leveling mortar, improve the aggregate suspension, and reduce the bleeding and water consumption sensitivity. Increasing the water consumption of 3-5% of the powder, the aggregate does not sink to the bottom, the surface does not bleed, the density difference between the upper and lower layers is less than 20 kg / m 3 , the initial flowability of the prepared self-leveling mortar and the flowability difference over time is less than 5 mm. Compared with the comparative sample, the cellulose ether proportion is reduced, the microbial thickening agent proportion is increased, the flowability loss over time is significantly increased, the cellulose ether proportion is increased, the microbial thickening agent proportion is reduced, the water consumption sensitivity is increased, the surface bleeding is produced, the powder dispersant proportion is reduced, the stirring uniformity is reduced, and the polyethylene oxide slurry viscosity is increased. Compared with the commonly used thickening agents such as cellulose ether, starch ether and magnesium aluminum silicate, the rheological stabilizer for self-leveling mortar prepared by the present application has obvious advantages in many indicators.

Claims

1. A rheology stabilizer for self-leveling mortar, characterized in that, The raw materials include the following parts by weight: Low viscosity cellulose ethers 15.0-20.0 Microbial thickener 10.0-13.0 Powder dispersant 17.0-24.0 Polymer lubricant 20.0-25.0 Packing material 25.0-35.0; The low-viscosity cellulose ether is one of hydroxypropyl cellulose and hydroxyethyl cellulose, with a viscosity of less than 4000 mPa·s; The microbial thickener is one of xanthan gum, gellan gum, and styrene gum; The powder dispersant is one of sodium polyphosphate, sodium tripolyphosphate, and sodium butylnaphthalene sulfonate; The aforementioned polymeric lubricant is polyethylene oxide; The filler is one of wollastonite powder and talc powder.

2. The application of the rheology stabilizer for self-leveling mortar as described in claim 1, characterized in that: When rheology stabilizers for self-leveling mortar are used in the production of cement-based self-leveling mortar, the dosage of the rheology stabilizer is 0.06-0.10% of the total weight of the cement-based self-leveling mortar. When rheology stabilizers for self-leveling mortar are used in the production of gypsum-based self-leveling mortar, the dosage of the rheology stabilizer is 0.04-0.08% of the total weight of the gypsum-based self-leveling mortar.

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