Construction method for improving whole-body compactness of cement-based self-leveling material

Abstract

The invention belongs to the technical field of building grounds, and particularly relates to a construction method for improving the whole-body compactness of a cement-based self-leveling material, which comprises the following steps: doping 0.1-0.3 wt% of viscosity reduction aid into a cement-based self-leveling premix, then mixing the cement-based self-leveling premix with water, and uniformly stirring to obtain a cement-based self-leveling slurry material; the viscosity reduction auxiliary agent is prepared from silicate, phosphate and potassium ferrocyanide according to the mass ratio of 1: (0.5 to 2): (0.01 to 0.05); (2) treating for a period of time under the conditions of negative pressure and stirring; and (3) pumping to a construction working surface needing to be poured through a pipeline. According to the present invention, the micro-bubbles in the cement-based self-leveling slurry material can be efficiently eliminated, the whole body compactness of the cement-based self-leveling material can be improved, the self-leveling surface hardness and the appearance flatness can be substantially improved, the problems of repeated floor polishing, repairing, leveling and the like caused by the poor micro-bubble effect can be avoided, the construction efficiency can be improved, the cost can be saved, and the facing effect can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of building floors, and in particular relates to a construction method for improving the overall compactness of a cement-based self-leveling material. Background Art

[0002] The demand for flooring industry in the fields of construction, transportation and infrastructure construction continues to grow, not only limited to residential buildings, but also expanded to commercial buildings, public works, airport pavements and other fields. With the rapid development of these fields, the market size of the flooring industry is also expanding.

[0003] The market demand for cement-based floor is increasing year by year due to its advantages such as high flatness, labor saving, high construction efficiency, safety and high efficiency, and high cost performance. However, there are still some shortcomings in the application of cement-based materials. Cement-based self-leveling materials use a high amount of water during the mixing process. During the high-speed mixing process, more gas will be introduced, resulting in a large number of bubbles in the cement-based self-leveling slurry material. Most of these bubbles will disappear through the defoaming treatment of the defoaming roller during the thin layer paving of the cement-based self-leveling slurry, but some will still remain in the slurry and stay in the hardened cement-based floor material or on the surface of the hardened body. This will result in poor surface effect and many pinholes on the floor after the decorative coating is paved, which greatly affects customer recognition. This has caused great obstacles to the promotion of cement-based self-leveling materials and is a key issue that needs to be urgently solved in the promotion of floor materials. Summary of the invention

[0004] In order to solve the problems of high air content and many pinholes on the surface of the hardened body of the existing cement-based self-leveling material slurry, the present invention provides a construction method for improving the overall density of the cement-based self-leveling material. Through the optimization design of the viscosity-reducing component and the combination of a vacuum negative pressure rotating device, the whole process from component viscosity reduction to process defoaming solves the problems of high air content and many pinholes on the surface of the hardened body of the cement-based self-leveling material, forming a cement-based self-leveling with high flatness, high hardness and no bubbles, and combined with color / transparent finishing materials, a floor system with high decorative effect is formed.

[0005] Specifically, the present invention provides the following technical solutions:

[0006] A construction method for improving the overall density of a cement-based self-leveling material comprises the following steps:

[0007] (1) adding a viscosity reducing agent to a cement-based self-leveling premix, then mixing the premix with water and stirring evenly to obtain a cement-based self-leveling slurry material;

[0008] The viscosity reducing agent is a mixture of silicate, phosphate and potassium ferrocyanide in a mass ratio of 1:0.5-2:0.01-0.05; the amount of the viscosity reducing agent added is 0.1-0.3wt% based on the mass of the cement-based self-leveling premix;

[0009] (2) adding the cement-based self-leveling slurry material into a vacuum rotating device and treating it under negative pressure and stirring conditions for a period of time;

[0010] (3) After the pressure is balanced, the cement-based self-leveling slurry material is pumped through a pipeline to the construction surface to be poured, and then spread and leveled using a trowel, and finally the surface is defoamed using a defoaming roller.

[0011] Preferably, in step (1), the silicate is sodium silicate, potassium silicate or a mixture of the two;

[0012] The phosphate is sodium phosphate, aluminum phosphate or a mixture of the two.

[0013] Preferably, in step (1), before mixing with water, part of the aggregate in the cement-based self-leveling premix is ​​replaced with fine aggregate; the mass of the replaced fine aggregate is 5 to 10 wt% of the total mass of the aggregate;

[0014] The fine aggregate has a mesh size of 70-140 meshes, a saturated surface dry water absorption rate of 0.1-0.5%, and a spherical particle shape; and measured by a Mohs hardness meter, the surface hardness of the fine aggregate is ≥ level 7.

[0015] Preferably, in step (1), the fluidity of the obtained cement-based self-leveling slurry material is ≥145 mm.

[0016] Preferably, in step (1), the stirring speed is below 900 r / min.

[0017] Preferably, in step (2), the absolute pressure of the negative pressure is 1-5 kPa;

[0018] The stirring speed is 200-600r / min;

[0019] The period of time is 10-30s.

[0020] The beneficial effects achieved by the present invention are:

[0021] (1) The present invention provides a construction method for improving the overall compactness of a cement-based self-leveling material, wherein a viscosity reducing agent consisting of silicate, phosphate and potassium ferrocyanide is added to a cement-based self-leveling premix, wherein potassium ferrocyanide has an effect of resisting agglomeration / agglomeration of powder materials and promoting efficient dispersion of materials; after adding water, the silicate and phosphate fully react with the gelling components in the cement-based material, thereby reducing the surface tension of the cement-based material, so that during the stirring process, the slurry is subjected to shear force, the molecules are more likely to slide and arrange in a more orderly manner, and the bubbles in the slurry are more likely to be discharged;

[0022] At the same time, the mass ratio of silicate, phosphate and potassium ferrocyanide also has a significant effect on the overall compactness. The present invention limits the mass ratio of the three to 1:0.5-2:0.01-0.05, thereby ensuring that the self-leveling surface obtained by construction has excellent overall compactness.

[0023] In addition, the study found that if the amount of viscosity reducing agent added is less than 0.1%, the viscosity reducing effect is poor, which affects the effect of eliminating bubbles. If the amount of viscosity reducing agent added is higher than 0.3%, the stability of the cement-based self-leveling slurry material will be poor, which may easily cause segregation or exudation of the slurry.

[0024] (2) The present invention provides a construction method for improving the overall density of cement-based self-leveling materials. Fine aggregate is added to the cement-based self-leveling premix. The saturated surface dry water absorption rate of the fine aggregate is 0.1-0.5%, and the water requirement is low. Under the same water consumption, there will be more surplus water, which helps to reduce the viscosity of the slurry. At the same time, the fine aggregate is spherical particles, which increases the rolling performance between the slurry and is more conducive to eliminating the dissipation of bubbles in the slurry, thereby achieving the effect of improving the density of the slurry.

[0025] (3) The present invention provides a construction method for improving the overall density of cement-based self-leveling materials. A slurry material obtained by mixing a cement-based self-leveling premix with water is added to a vacuum rotating device. High-speed rotation and vacuum negative pressure are used to destroy the bubbles inside the slurry during movement until they disappear. Finally, a high-flatness, high-hardness, bubble-free cement-based self-leveling material is formed on the final pouring construction surface. Combined with color / transparent finishing materials, a floor system with high decorative effect can be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the base surface obtained after the construction of Examples 1-3, which correspond to Example 1, Example 2 and Example 3 from left to right respectively.

[0027] Figure 2 Schematic diagram of the base surface obtained after the construction of comparative examples 1-3, which correspond to comparative example 1, comparative example 2 and comparative example 3 from left to right respectively. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in the field or the product manual shall be followed.

[0029] In the following examples, the mass ratios of the components of the cement-based self-leveling premix used are:

[0030] PO 42.5 cement: fly ash: silica fume: limestone powder: expansive agent: water reducing agent: latex powder: 40-70 mesh quartz sand = 50:20:15:15:2:6:5:100.

[0031] Among them, the expansion agent is a calcium sulfoaluminate-calcium oxide composite expansion agent, the water reducer is a polycarboxylic acid high-efficiency water reducer, and the latex powder is a water-soluble redispersible powder, which is mainly a copolymer of ethylene / vinyl acetate.

[0032] Example 1

[0033] A construction method for improving the overall density of cement-based self-leveling materials, the steps are as follows:

[0034] (1) adding 0.1wt% of a viscosity reducing agent to the cement-based self-leveling premix, wherein the mass ratio of the components of the viscosity reducing agent is: 1 part of silicate: 0.5 part of phosphate: 0.01 part of potassium ferrocyanide; the silicate is sodium silicate, and the phosphate is sodium phosphate;

[0035] Meanwhile, part of the quartz sand in the cement-based self-leveling premix is ​​replaced with fine quartz sand; the mass of the replaced fine quartz sand is 5wt% of the total mass of the quartz sand. The mesh number of the fine quartz sand is 70-140 meshes, the saturated surface dry water absorption rate is 0.1%, the morphology is spherical particles, and the surface hardness of the aggregate is 7 when measured by a Mohs hardness tester.

[0036] Mix the mixing water and cement-based self-leveling premix in a mass ratio of 0.4:1, and stir them thoroughly at a speed of 700r / min for 2 minutes to form a uniform self-leveling slurry material;

[0037] (2) The self-leveling slurry material is transported to the vacuum negative pressure rotating device through a conveying pipeline. After closing, the speed is adjusted to 200 r / min, the absolute pressure is 3 kPa, and the vacuum negative pressure and high-speed rotation treatment are carried out for 15 seconds;

[0038] (3) After the pressure is balanced, the self-leveling slurry material is pumped through a pipeline to the ground / floor to be poured; it is spread flat with a trowel and the surface is defoamed with a defoaming roller.

[0039] The self-leveling slurry material has a fluidity of 145 mm and a fluidity of 140 mm in half an hour.

[0040] The cleaning method of the vacuum negative pressure rotating device is: add 15% of the mixing water of the barrel capacity, open about 200r / min, and clean for 10s; discharge the cleaned water through the pipeline; then add 10% of the mixing water of the barrel capacity, open about 200r / min, and clean for 10s, and discharge it cleanly.

[0041] Example 2

[0042] A construction method for improving the overall density of cement-based self-leveling materials, the steps are as follows:

[0043] (1) adding 0.2 wt% of a viscosity reducing agent to the cement-based self-leveling premix, wherein the mass ratio of the components of the viscosity reducing agent is: 1 part of silicate: 1 part of phosphate: 0.05 part of potassium ferrocyanide; the silicate is potassium silicate, and the phosphate is aluminum phosphate;

[0044] Meanwhile, part of the quartz sand in the cement-based self-leveling premix is ​​replaced with fine quartz sand; the mass of the replaced fine quartz sand is 10wt% of the total mass of the quartz sand. The mesh number of the fine quartz sand is 70-140 meshes, the saturated surface dry water absorption rate is 0.3%, the morphology is spherical particles, and the surface hardness of the aggregate is 8 levels when measured by a Mohs hardness tester.

[0045] Mix the mixing water and cement-based self-leveling premix in a mass ratio of 0.35:1, and stir thoroughly for 2 minutes at a speed of 700r / min to form a uniform self-leveling slurry material;

[0046] (2) The self-leveling slurry material is transported to a vacuum negative pressure rotating device through a conveying pipeline, with a rotation speed of 600 r / min, an absolute pressure of 5 kPa, and a vacuum negative pressure and high-speed rotation treatment for 15 seconds;

[0047] (3) After the pressure is balanced, the self-leveling slurry material is pumped through a pipeline to the ground / floor to be poured; it is spread flat with a trowel and the surface is defoamed with a defoaming roller.

[0048] The self-leveling slurry material has an initial fluidity of 148 mm and a fluidity of 145 mm after half an hour.

[0049] The cleaning method of the vacuum negative pressure rotating device is: add 30% of the mixing water of the barrel capacity, open about 400r / min, and clean for 15s; discharge the cleaned water through the pipeline; then add 15% of the mixing water of the barrel capacity, open about 400r / min, and clean for 15s, and discharge it cleanly.

[0050] Example 3

[0051] A construction method for improving the overall density of cement-based self-leveling materials, the steps are as follows

[0052] (1) 0.3 wt% of a viscosity reducing agent is added to the cement-based self-leveling premix, wherein the mass ratio of the viscosity reducing agent components is: 1 part of silicate: 2 parts of phosphate: 0.05 parts of potassium ferrocyanide; the silicate is a composite component of sodium silicate and potassium silicate in a mass ratio of 2:1, and the phosphate is a composite component of sodium phosphate and aluminum phosphate in a mass ratio of 2:1;

[0053] Meanwhile, part of the quartz sand in the cement-based self-leveling premix is ​​replaced with fine corundum, and the mass of the replaced fine corundum is 10wt% of the total mass of the quartz sand. The mesh number of the fine corundum is 70-140 meshes, the saturated surface dry water absorption rate is 0.2%, the morphology is spherical particles, and the surface hardness of the aggregate is measured by a Mohs hardness tester. 9.

[0054] Mix the mixing water and cement-based self-leveling premix in a mass ratio of 0.45:1, and stir thoroughly for 2 minutes at a speed of 700r / min to form a uniform self-leveling slurry material;

[0055] (2) The self-leveling slurry material is transported to a vacuum negative pressure rotating device through a conveying pipeline, with a rotation speed of 600 r / min, an absolute pressure of 1 kPa, and a vacuum negative pressure and high-speed rotation treatment for 30 seconds;

[0056] (3) After the pressure is balanced, the self-leveling slurry material is pumped through a pipeline to the ground / floor to be poured; it is spread flat with a trowel and the surface is defoamed with a defoaming roller.

[0057] The self-leveling slurry material has a fluidity of 150 mm and a fluidity of 140 mm in half an hour.

[0058] The cleaning method of the vacuum negative pressure rotating device is: add 30% of the mixing water of the barrel capacity, open about 300r / min, and clean for 15s; discharge the cleaned water through the pipeline; then add 15% of the mixing water of the barrel capacity, open about 400r / min, and clean for 15s, and discharge it cleanly.

[0059] Comparative Example 1

[0060] A construction method of a cement-based self-leveling material, the steps are as follows:

[0061] (1) 0.3 wt% of a viscosity reducing agent is added to the cement-based self-leveling premix, wherein the mass ratio of the viscosity reducing agent components is: 1 part of silicate: 1 part of phosphate: 0.05 part of potassium ferrocyanide; the silicate is a composite component of sodium silicate and potassium silicate in a mass ratio of 1:1, and the phosphate is a composite component of sodium phosphate and aluminum phosphate in a mass ratio of 1:1;

[0062] Meanwhile, part of the quartz sand in the cement-based self-leveling premix is ​​replaced with fine quartz sand; the mass of the replaced fine quartz sand is 10wt% of the total mass of the quartz sand. The fine quartz sand has a mesh size of 70-140 meshes, a saturated surface dry water absorption rate of 0.5%, a spherical particle shape, and a Mohs hardness tester is used to measure that the aggregate surface hardness is level 8.

[0063] Mix the mixing water and cement-based self-leveling premix in a mass ratio of 0.4:1, and stir them thoroughly at a speed of 700r / min for 2 minutes to form a uniform self-leveling slurry material;

[0064] (2) The self-leveling slurry material is pumped to the ground / floor to be poured through a pipeline; it is spread flat with a trowel and the surface is defoamed with a defoaming roller.

[0065] The self-leveling slurry material has a fluidity of 150 mm and a fluidity of 140 mm in half an hour.

[0066] Comparative Example 2

[0067] A construction method of a cement-based self-leveling material, the steps are as follows:

[0068] (1) Mix mixing water and cement-based self-leveling premix in a mass ratio of 0.35:1, and stir them thoroughly at a speed of 700 r / min for 2 min to form a uniform self-leveling slurry material;

[0069] (2) The self-leveling slurry material is transported to a vacuum negative pressure rotating device through a conveying pipeline, with a rotation speed of 400 r / min, an absolute pressure of 5 kPa, and a vacuum negative pressure and high-speed rotation treatment for 10 s;

[0070] (3) After the pressure is released, the self-leveling slurry material is pumped through a pipeline to the ground / floor to be poured; it is spread flat with a leveling tool, and the surface is defoamed with a defoaming roller.

[0071] The cement-based self-leveling premix does not contain the viscosity reducing agent described in the present invention;

[0072] The cement-based self-leveling premix is ​​not mixed with the fine aggregate described in the present invention;

[0073] The self-leveling slurry material has a fluidity of 150 mm and a fluidity of 140 mm in half an hour.

[0074] The cleaning method of the vacuum negative pressure rotating device is: add 30% of the mixing water of the barrel capacity, open about 300r / min, and clean for 15s; discharge the cleaned water through the pipeline; then add 15% of the mixing water of the barrel capacity, open about 400r / min, and clean for 15s, and discharge it cleanly.

[0075] Comparative Example 3

[0076] A construction method of a cement-based self-leveling material, the steps are as follows:

[0077] (1) Mix mixing water and cement-based self-leveling premix in a mass ratio of 0.45:1, and stir them thoroughly at a speed of 700 r / min for 2 minutes to form a uniform self-leveling slurry material;

[0078] (2) The self-leveling slurry material is pumped to the ground / floor to be poured through a pipeline; it is spread flat with a trowel and the surface is defoamed with a defoaming roller.

[0079] The cement-based self-leveling premix does not contain the viscosity reducing agent described in the present invention;

[0080] The cement-based self-leveling premix is ​​not mixed with the fine aggregate described in the present invention;

[0081] The self-leveling slurry material has a fluidity of 140 mm and a fluidity of 130 mm in half an hour.

[0082] Figure 1 This is a schematic diagram of the base surface obtained after the construction of Example 1-3, Figure 2 It is a schematic diagram of the base surface obtained after the construction of comparative examples 1 to 3. It can be seen from the comparison that the construction method for improving the overall density of cement-based self-leveling materials provided by the present invention can significantly improve the overall density of cement-based self-leveling materials and significantly improve the surface effect.

[0083] Although the present invention has been described in detail above by general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A construction method for improving the overall density of cement-based self-leveling materials, characterized in that: The following steps are involved: (1) adding a viscosity reducing agent to a cement-based self-leveling premix, then mixing the premix with water and stirring evenly to obtain a cement-based self-leveling slurry material; The viscosity reducing agent is a mixture of silicate, phosphate and potassium ferrocyanide in a mass ratio of 1:0.5-2:0.01-0.05; the amount of the viscosity reducing agent added is 0.1-0.3wt% based on the mass of the cement-based self-leveling premix; (2) adding the cement-based self-leveling slurry material into a vacuum rotating device and treating it under negative pressure and stirring conditions for a period of time; (3) After the pressure is balanced, the cement-based self-leveling slurry material is pumped through a pipeline to the construction surface to be poured, and then spread and leveled using a trowel, and finally the surface is defoamed using a defoaming roller.

2. A construction method for improving the overall density of cement-based self-leveling materials according to claim 1, characterized in that: In step (1), the silicate is sodium silicate, potassium silicate or a mixture of the two; The phosphate is sodium phosphate, aluminum phosphate or a mixture of the two.

3. A construction method for improving the overall compactness of cement-based self-leveling materials according to claim 1 or 2, characterized in that: In step (1), before mixing with water, part of the aggregate in the cement-based self-leveling premix is ​​replaced with fine aggregate; the mass of the replaced fine aggregate is 5 to 10 wt% of the total mass of the aggregate; The fine aggregate has a mesh size of 70-140 meshes, a saturated surface dry water absorption rate of 0.1-0.5%, and a spherical particle shape; and measured by a Mohs hardness meter, the surface hardness of the fine aggregate is ≥ level 7.

4. A construction method for improving the overall compactness of cement-based self-leveling materials according to claim 1 or 2, characterized in that: In step (1), the fluidity of the obtained cement-based self-leveling slurry material is ≥145 mm.

5. A construction method for improving the overall compactness of cement-based self-leveling materials according to claim 1 or 2, characterized in that: In step (1), the stirring speed is below 900 r / min.

6. A construction method for improving the overall compactness of cement-based self-leveling materials according to claim 1 or 2, characterized in that: In step (2), the absolute pressure of the negative pressure is 1-5 kPa; The stirring speed is 200-600r / min; The period of time is 10-30s.

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