Stone adhesive for plateau regions and preparation method thereof

Abstract

A stone adhesive for plateau areas relates to the technical field of building materials and comprises the following components in parts by weight: 250-450 parts of cement, 100-300 parts of an admixture, 450-600 parts of sand, 1-5 parts of carbon nanotubes, 3-15 parts of nano-silica, 0.2-0.6 part of a water-retaining agent, 0.01-0.05 part of an air entraining agent, 2-5 parts of a negative temperature early strength agent and 35-55 parts of redispersible latex powder. The invention also provides a preparation method of the stone adhesive for the plateau region, and the preparation method comprises the following steps: S1, respectively weighing the cement, the admixture, the carbon nano tube, the nano silicon dioxide, the water-retaining agent, the air entraining agent, the negative temperature early strength agent and the water reducing agent according to the amount, and uniformly mixing and stirring for later use; s2, quantitative sand and renewable latex powder are added into the mixed material prepared in the step S1, the mixture is mixed and stirred to be uniform, and the stone binder is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a stone adhesive for use in plateau areas and a preparation method thereof. Background Art

[0002] Stone is a building material with both architectural and decorative functions. With the progress of society and the prosperity of the construction market, stone is being used more and more widely in the construction field and has also made great progress in the decoration field.

[0003] When stone is used as indoor and outdoor wall and floor material, its installation methods include dry hanging, wet pasting, wet hanging or dry bonding. Dry hanging means fixing it to the wall through a base frame, and then hanging the slotted stone on the frame with dry hanging parts; wet pasting means directly sticking the stone slabs to the exterior wall of the building through stone adhesive; wet hanging means using cement mortar as the bonding material for the base layer, hanging the slabs first and then pouring mortar; the process flow of dry bonding is: cleaning the wall base layer and measuring the base layer → measuring and laying out → treating the base layer at the glue points → drilling holes in the wall → mixing super glue → planting rebar → pasting stone. The above four installation methods have different requirements for the thickness, specifications and base conditions of the stone. Most of the existing decorative stones are processed standard plates, which can be installed in different ways. However, for naturally formed irregular small plate thin stone, only construction can be selected. Moreover, in plateau areas, due to the environmental characteristics of low pressure, low temperature, large temperature difference between day and night, ice, snow and freezing rain, ordinary stone adhesives cannot meet the requirements. After paving, it is easy to have quality problems such as hollowing, falling off, alkali return, rust return, etc. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a stone adhesive for use in plateau areas and a preparation method thereof, which solves the problem that the stone adhesive in the prior art has insufficient performance and cannot meet the quality requirements of plateau stone construction.

[0005] A stone adhesive for plateau areas comprises, by weight, 250-450 parts of cement, 100-300 parts of admixtures, 450-600 parts of sand, 1-5 parts of carbon nanotubes, 3-15 parts of nano silicon dioxide, 0.2-0.6 parts of water retaining agent, 0.01-0.05 parts of air entraining agent, 2-5 parts of negative temperature early strength agent and 35-55 parts of redispersible latex powder.

[0006] Preferably, the cement is P.O42.5 Portland cement.

[0007] Preferably, the admixture is one or more of fly ash, slag powder or limestone powder.

[0008] Preferably, the sand is natural sand or artificial sand, with a mud content of <0.5%. Calculated by mass fraction, the particle size distribution of the natural sand or artificial sand is: 0 on a 20-mesh sieve, >65% on a 40-mesh sieve, >85% on an 80-mesh sieve, and >96% on a 150-mesh sieve.

[0009] Preferably, the carbon nanotubes have a diameter of 6 to 13 nm and a length of 2.5 to 25 μm.

[0010] Preferably, the particle size of the nano-silicon dioxide is 15±5nm and the specific surface area is 200±6m 2 / g.

[0011] Preferably, the water retaining agent is one or more of hydroxypropyl methylcellulose or hydroxyethyl methylcellulose, and has a viscosity of 100,000-200,000 mPa·s.

[0012] Preferably, the air entraining agent is one or more of rosin resins, alkyl and alkyl aromatic sulfonic acids or fatty alcohol sulfonates and saponins.

[0013] Preferably, the negative temperature early strength agent is a combination of sodium sulfate, calcium formate and lithium carbonate, and the mass ratio of sodium sulfate, calcium formate and lithium carbonate is 1:1:3.

[0014] The present invention also provides a method for preparing a stone adhesive for use in plateau areas, comprising the following steps:

[0015] S1. Weigh cement, admixture, carbon nanotubes, nano-silicon dioxide, water-retaining agent, air-entraining agent, negative temperature early strength agent, and water-reducing agent respectively, mix and stir evenly, and set aside;

[0016] S2. Add a certain amount of sand and renewable latex powder to the mixture prepared in S1, and mix and stir evenly to obtain a stone binder.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention solves the problem of thermal expansion and contraction or wet expansion and dry shrinkage of stone binders during the curing process due to the large temperature difference between day and night, which causes irreversible damage to the bonding force, by rationally optimizing the percentage of water retaining agent, air entraining agent, negative temperature early strength agent, water reducing agent, and renewable latex powder. Secondly, it reduces the adverse effects of the reduction of environmental air pressure and humidity on stone binders. Under the influence of humidity gradient, the moisture inside the stone binder continuously migrates to the outside and evaporates, further reducing the humidity environment inside the stone binder, thereby affecting the normal hydration of cement in the stone binder, causing changes in the composition and morphology of the hydration products, and deterioration of the pore structure, which will lead to a reduction in the bonding strength of the stone binder and thus affect the bonding effect. The present invention has significantly improved the above problems.

[0019] 2. The carbon nanotubes and nano-silicon dioxide in the present invention are mainly used for nano-modification of stone binders. In the plateau area, the long-term negative temperature climate will cause cement and other cementitious materials in the newly mixed stone binder to fail to hydrate normally, or even stop hydrating, and fail to form effective bonding strength; and for the stone binder that has formed a hardened body, it will suffer from frost damage in a low-temperature freeze-thaw environment, resulting in cracking and strength reduction. After adding carbon nanotubes and nano-silicon dioxide for nano-modification, the hydration degree of cement in low humidity and low pressure environments can be improved, the early cement hydration degree can be improved, the microstructure can be compacted, and early water evaporation can be reduced, thereby ensuring the humidity environment inside the specimen, reducing the risk of early water bleeding in the system, and improving the homogeneity and workability of the system.

[0020] 3. The present invention adds redispersible latex powder. When the cement solidifies, the latex powder immediately disperses into an emulsion when it meets water and gathers in the cavity. As the drying process proceeds, the emulsion is dehydrated again, and the polymer forms a continuous film around the cavity, strengthening these weak parts. The polymer film has a hydrophobic effect and will not block the pores, so that the material has good hydrophobicity and air permeability.

[0021] 4. The selected admixtures are lower in carbon content and cheaper in price than silicate cement, and have more environmentally friendly properties and cost advantages. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and functions of the present invention clearer and easier to understand, the present invention is further described below in conjunction with specific embodiments:

[0023] Example 1

[0024] S1. Weigh 250g of P.O42.5 silicate cement, 100g of fly ash, 1g of carbon nanotubes, 3g of nano-silicon dioxide, 0.2g of hydroxypropyl methylcellulose, 0.01g of modified rosin resin, 2g of negative temperature early strength agent, mix and stir evenly for use;

[0025] S2. Add a certain amount of natural sand 450 g and dispersible latex powder 35 g to the mixture prepared in S1, and mix and stir evenly to obtain a stone binder.

[0026] Example 2

[0027] S1. Weigh 450g of P.O42.5 Portland cement, 300g of slag powder, 5g of carbon nanotubes, 15g of nano-silica, 0.6g of hydroxyethyl methylcellulose, 0.05g of dialkylbenzene sulfonate, 5g of negative temperature early strength agent, mix and stir evenly for use;

[0028] S2. Add a certain amount of natural sand 600 g and dispersible latex powder 55 g to the mixture prepared in S1, and mix and stir evenly to obtain a stone binder.

[0029] Example 3

[0030] S1. Weigh 300g of P.O42.5 silicate cement, 200g of limestone powder, 3g of carbon nanotubes, 9g of nano-silica, 0.4g of hydroxypropyl methylcellulose and 0.03g of hydroxyethyl methylcellulose, 0.03g of stearyl alcohol sulfonate, 3g of negative temperature early strength agent, mix and stir evenly for use;

[0031] S2. Add a certain amount of artificial sand 550g and dispersible latex powder 40g to the mixed material prepared in S1, and mix and stir evenly to obtain a stone binder.

[0032] Example 4

[0033] S1. Weigh 400g of P.O42.5 silicate cement, 150g of fly ash and limestone powder, 2g of carbon nanotubes, 6g of nano-silica, 0.3g of hydroxypropyl methylcellulose, 0.02g of sophora flavescens saponin, 4g of negative temperature early strength agent, mix and stir evenly for use;

[0034] S2. Add a certain amount of artificial sand 500g and dispersible latex powder 45g to the mixed material prepared in S1, and mix and stir evenly to obtain a stone binder.

[0035] Example 5

[0036] S1. Weigh 350g of P.O42.5 silicate cement, 250g of fly ash and slag powder, 4g of carbon nanotubes, 12g of nano-silica, 0.5g of hydroxyethyl methyl cellulose, 0.04g of modified rosin resin and dialkylbenzene sulfonate, 3.5g of negative temperature early strength agent, mix and stir evenly for use;

[0037] S2. Add a certain amount of natural sand 570 g and dispersible latex powder 50 g to the mixture prepared in S1, and mix and stir evenly to obtain a stone binder.

[0038] Comparative Example 1

[0039] Compared with Example 1, no carbon nanotubes were added, and the remaining steps were the same.

[0040] Comparative Example 2

[0041] Compared with Example 1, no nano silicon dioxide was added, and the remaining steps were the same.

[0042] Comparative Example 3

[0043] Compared with Example 1, no carbon nanotubes and nano-silicon dioxide are added, and the remaining steps are the same.

[0044] The stone binders prepared in Examples 1-5 and Comparative Examples 1-3 were mixed and stirred uniformly in a mass ratio of stone binder: water = 4:1 to form a stone binder slurry, and its performance was tested according to the provisions of JC / T 547-2017. The test results are shown in the following table:

[0045]

[0046] It can be seen from the above table that the stone adhesives prepared in Examples 1-5 have good tensile bonding strength and tensile bonding strength after water seepage, and by comparing Comparative Examples 1-3 with Example 1, the addition of carbon nanotubes and nano-silicon dioxide has a significant effect on the tensile bonding strength and tensile bonding strength after water seepage of the stone adhesive.

[0047] According to Comparative Examples 1-2, it can be seen that carbon nanotubes not only enhance the tensile strength, but also improve the crack resistance and toughness of cement, which is particularly important for improving the bonding strength. In the absence of carbon nanotubes, the tensile bonding strength of the stone adhesive and the tensile bonding strength after water seepage will be significantly reduced; while nano-silicon dioxide plays an important role in improving the density and strength of cement, but compared with carbon nanotubes, its effect on the tensile bonding strength and the tensile bonding strength after water seepage is more indirect. Therefore, in the absence of nano-silicon dioxide, although the tensile bonding strength will be reduced, the main impact is still the tensile bonding strength after water seepage.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A stone adhesive for use in plateau areas, characterized in that: Calculated in parts by weight, it includes 250-450 parts of cement, 100-300 parts of admixtures, 450-600 parts of sand, 1-5 parts of carbon nanotubes, 3-15 parts of nano-silicon dioxide, 0.2-0.6 parts of water retaining agent, 0.01-0.05 parts of air entraining agent, 2-5 parts of negative temperature early strength agent and 35-55 parts of redispersible latex powder.

2. The stone adhesive for plateau areas according to claim 1, characterized in that: The cement is P.O42.5 silicate cement.

3. The stone adhesive for plateau areas according to claim 1, characterized in that: The admixture is one or more of fly ash, slag powder or limestone powder.

4. The stone adhesive for plateau areas according to claim 1, characterized in that: The sand is natural sand or artificial sand, with a mud content of less than 0.5%. Calculated by mass fraction, the particle size distribution of the natural sand or artificial sand is: 0 on a 20-mesh sieve, >65% on a 40-mesh sieve, >85% on an 80-mesh sieve, and >96% on a 150-mesh sieve.

5. The stone adhesive for plateau areas according to claim 1, characterized in that: The carbon nanotubes have a diameter of 6 to 13 nm and a length of 2.5 to 25 μm.

6. The stone adhesive for plateau areas according to claim 1, characterized in that: The particle size of the nano-silicon dioxide is 15±5nm and the specific surface area is 200±6m 2 / g.

7. The stone adhesive for plateau areas according to claim 1, characterized in that: The water retaining agent is one or more of hydroxypropyl methylcellulose and hydroxyethyl methylcellulose, and has a viscosity of 100000-200000 mPa·s.

8. The stone adhesive for plateau areas according to claim 1, characterized in that: The air entraining agent is one or more of rosin resin, alkyl aromatic hydrocarbon sulfonic acid, fatty alcohol sulfonate or saponin.

9. The stone adhesive for plateau areas according to claim 1, characterized in that: The negative temperature early strength agent is composed of sodium sulfate, calcium formate and lithium carbonate, and the mass ratio of sodium sulfate, calcium formate and lithium carbonate is 1:1:

3.

10. A method for preparing a stone adhesive for use in plateau areas according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Weigh cement, admixture, carbon nanotubes, nano-silicon dioxide, water-retaining agent, air-entraining agent, negative temperature early strength agent, and water-reducing agent respectively, mix and stir evenly, and set aside; S2. Add a certain amount of sand and renewable latex powder to the mixture prepared in S1, and mix and stir evenly to obtain a stone binder.

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