Early-strength ceramic tile adhesive suitable for prefabricated building and preparation method thereof

Abstract

The invention relates to an early strength ceramic tile adhesive suitable for prefabricated buildings, and the early strength ceramic tile adhesive is prepared from the following raw materials in parts by weight: 20 to 50 parts of cement, 4 to 12 parts of mineral admixture, 50 to 95 parts of graded aggregate, 1 to 6 parts of rubber powder, 0.01 to 0.1 part of early strength agent, 0.01 to 0.05 part of thickening agent and 0.03 to 0.12 part of super absorbent resin, 0.3 to 2 parts of chopped fiber; and 20 to 65 parts of water. The particle size of particles in the graded aggregate ranges from 2.36 mm to 0.020 mm; in the graded aggregate, the content of particles with the particle size larger than 0.080 mm does not exceed 80%, the content of particles with the particle size larger than 0.170 mm is not lower than 58%, and the content of particles with the particle size larger than 0.800 mm does not exceed 38%; the super absorbent resin can absorb water which is 100-400 times of the weight of the super absorbent resin; the particle size of the super absorbent resin is 180 microns to 420 microns. The problems that in the prior art, after cement-based ceramic tile glue is used for paving ceramic tiles in an assembly type building module, the ceramic tiles are prone to hollowing, falling off, displacement and the like due to disturbance in the transportation and hoisting process are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and particularly relates to an early-strength ceramic tile adhesive suitable for prefabricated buildings and a preparation method thereof. Background Art

[0002] As a common decorative material, ceramic tiles are widely used in the decoration of indoor and outdoor walls and floors. The traditional ceramic tile paving process is usually carried out at the construction site of a building. Construction workers use ceramic tile adhesive to stick ceramic tiles piece by piece to the working surface to complete the decoration process of the ceramic tiles. Among them, cement-based ceramic tile adhesive is widely used due to its low cost, wide applicability, strong durability and air permeability. With the rapid development of prefabricated building technology in recent years, ceramic tiles can also be directly paved on prefabricated building modules in a prefabricated building factory. After the prefabricated building module with ceramic tiles is transported to the building construction site, only simple assembly is required to complete the construction of the entire building.

[0003] However, since the prefabricated building modules often need to be transported and hoisted multiple times after being prefabricated in the prefabricated building factory before assembly can be completed. After the existing cement-based ceramic tile adhesive is paved, it is very easy to delaminate or crack due to disturbances during transportation and hoisting (strong vibrations and collisions may occur during transportation and hoisting), which may lead to problems such as ceramic tile hollowing, falling off and displacement. Moreover, limited by factors such as construction period and site, after the ceramic tiles are paved in place in the prefabricated building factory, they are often quickly transported to the construction site (the storage time is generally no more than 2-3 days), and the curing time of the ceramic tile adhesive is insufficient, and the bonding strength is low. This insufficient early strength will further exacerbate problems such as ceramic tile hollowing, falling off and displacement during the transportation of prefabricated building modules, affecting the installation quality and durability of the ceramic tiles.

[0004] It is worth mentioning that in the existing production and operation processes of prefabricated building factories, in order to ensure that the tile adhesive in the prefabricated building modules has a certain early strength when leaving the factory and avoid a large number of problems such as tile cracking, peeling, or displacement after transportation of the prefabricated building modules, generally, increasing the cement content in the tile adhesive or using a combination of a large amount of early-strength agents and water-reducing agents is used to obtain an early-strength tile adhesive with sufficient early strength. However, this kind of tile adhesive has a high cost and a relatively low later strength. At the same time, this single method of increasing the early strength of the tile adhesive also has a relatively low compatibility with prefabricated buildings. Although its fast early strength development and fast hardening can reduce visible problems such as tile peeling and displacement, it also means that a large amount of concentrated hydration heat will be released during the intense hydration process of cement, which will cause severe shrinkage of the tile adhesive layer, resulting in invisible defects such as cracks and local bonding failure, affecting the later strength of the tile adhesive. The vibration and collision during the transportation of prefabricated buildings will further exacerbate these defects, causing problems such as turning micro-cracks into large cracks and tile hollowing at the large crack positions, further intensifying the tile hollowing and local bonding failure of the tile adhesive caused by the disturbance during transportation and hoisting processes, and then leading to a significant decline in the performance such as durability and sealing performance of the tile adhesive, which is not conducive to the long-term use of the tile adhesive. Summary of the Invention

[0005] (1) Technical problems to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a tile adhesive applicable to prefabricated buildings and a preparation method thereof, which solves the problems such as tile hollowing, peeling, and displacement easily caused by the disturbance during transportation and hoisting processes when using a cement-based tile adhesive to lay tiles in prefabricated building modules in the prior art.

[0007] (2) Technical solutions

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] In the first aspect, the present invention provides an early-strength tile adhesive applicable to prefabricated buildings, which is characterized in that, by weight, the raw materials of the early-strength tile adhesive include: 20 - 50 parts of cement, 4 - 12 parts of mineral admixture, 50 - 95 parts of graded aggregate, 1 - 6 parts of rubber powder, 0.01 - 0.1 part of early-strength agent, 0.01 - 0.05 part of thickener, 0.03 - 0.12 part of superabsorbent resin, 0.3 - 2 parts of chopped fiber, and 20 - 65 parts of water;

[0010] The particle size of the graded aggregate is between 2.36 mm and 0.020 mm; in the graded aggregate, the content of particles with a particle size greater than 0.080 mm does not exceed 80%, the content of particles with a particle size greater than 0.170 mm is not less than 58%, and the content of particles with a particle size greater than 0.800 mm does not exceed 38%.

[0011] The superabsorbent resin can absorb 100 - 400 times its own weight of water; the particle size of the superabsorbent resin is 180 μm - 420 μm.

[0012] The early strength agent includes at least one of nitrate early strength agent, carbonate early strength agent, organic early strength agent and sulfate early strength agent.

[0013] Optionally, by weight, the raw materials of the early strength tile adhesive include: 30 - 45 parts of cement, 6 - 10 parts of mineral admixture, 60 - 80 parts of graded aggregate, 2 - 4 parts of rubber powder, 0.02 - 0.06 parts of early strength agent, 0.01 - 0.02 parts of thickener, 0.05 - 0.1 parts of superabsorbent resin, 0.5 - 1 part of chopped fiber and 25 - 55 parts of water.

[0014] The mineral admixture is a mineral admixture made of clay minerals; in the graded aggregate, the content of particles with a particle size of 0.020 mm - 0.080 mm is 20 - 28 wt%, the content of particles with a particle size of 0.080 mm - 0.170 mm is 10 - 14 wt%, the content of particles with a particle size of 0.170 mm - 0.800 mm is 25 - 35 wt%, and the content of particles with a particle size of 0.800 mm - 2.36 mm is 30 - 38 wt%; the superabsorbent resin can absorb 250 - 350 times its own weight of water; the particle size of the superabsorbent resin is 220 μm - 380 μm; the early strength agent includes nitrate early strength agent, carbonate early strength agent and organic early strength agent; the cement is Portland cement and / or ordinary Portland cement.

[0015] Optionally, the superabsorbent resin includes at least one of sodium polyacrylate, polyacrylamide, polyvinyl alcohol grafted acrylate, cellulose grafted acrylate and acrylic acid - acrylamide copolymer.

[0016] Optionally, the cement is at least one of P.Ⅱ.52.5, P.Ⅱ.42.5, P.Ⅱ.52.5R, P.Ⅱ.42.5R, P.O.42.5 and P.O.52.5; the particle size of the cement does not exceed 80 μm; the specific surface area of the cement is 350 - 450 m2 / kg.

[0017] Optionally, the specific surface area of the mineral admixture is 22 - 28 m 2 / g; the mineral admixture includes at least one of kaolin powder, metakaolin powder, bentonite powder, sepiolite powder and illite powder.

[0018] Optionally, the graded aggregate includes at least one of river sand, lake sand, mountain sand, quartz sand, granite sand, basalt sand, and recycled sand.

[0019] Optionally, the rubber powder includes at least one of ethylene-vinyl acetate copolymer rubber powder, acrylate rubber powder, polyvinyl acetate rubber powder, styrene-butadiene rubber powder, polyvinyl alcohol rubber powder, polyurethane rubber powder, and starch ether rubber powder.

[0020] Optionally, the early strength agent includes at least one of calcium formate, lithium carbonate, lithium nitrate, and calcium nitrate.

[0021] Optionally, the thickener is a cellulose-based thickener; the cellulose-based thickener includes at least one of hydroxypropyl methylcellulose, methylcellulose, hydroxymethylcellulose, and hydroxyethylcellulose; the viscosity of the cellulose-based thickener is 90,000 - 110,000 Pa·s; the chopped fiber is wood fiber; the length of the wood fiber is 4 - 8 mm; the diameter of the wood fiber does not exceed 40 μm.

[0022] In a second aspect, the present invention also provides a method for preparing an early strength tile adhesive, including the following steps:

[0023] S1: Prepare the raw materials according to the parts of the raw materials of the early strength tile adhesive applicable to prefabricated buildings described in any item of the first aspect, and mix the superabsorbent resin with 10% - 20% of water to obtain a superabsorbent resin gel;

[0024] S2: Mix and stir the early strength agent, thickener, and the remaining 80% - 90% of water to obtain a wet material;

[0025] S3: Mix and stir the cement, mineral admixture, graded aggregate, rubber powder, and chopped fiber to obtain a dry material;

[0026] S4: Mix and stir the superabsorbent resin gel, dry material, and wet material to obtain an early strength tile adhesive applicable to prefabricated buildings.

[0027] (III) Beneficial effects

[0028] The beneficial effects of the present invention are as follows: Since the early-strength tile adhesive of the present invention adopts an optimized formula of cement + graded aggregate + early-strength agent + superabsorbent resin + wood fiber, the superabsorbent resin used in the formula has excellent water storage and water retention capabilities. Compared with the prior art, the superabsorbent resin can gradually release water at a relatively stable rate, enabling the early-strength tile adhesive of the present invention to maintain a relatively high internal humidity for a long time, significantly reducing the pressure on the capillary walls formed during internal hydration, resulting in less early shrinkage and less prone to cracking; the long-term maintenance of internal humidity can also stabilize its internal temperature, preventing phenomena such as bonding failure or hollowing caused by the concentration of cement hydration heat, facilitating the continuous and uniform hydration of concrete, making the cement hydration more uniform, and improving its later strength. At the same time, the formula of the present invention also uses a combination of graded aggregate + early-strength agent. The graded aggregate can improve the density, fluidity, and bonding strength of the early-strength tile adhesive of the present invention through the cooperation between particles of different particle sizes, reducing its shrinkage rate and cracking risk; at the same time, the graded aggregate can also cooperate with the early-strength agent to further improve the early strength of the early-strength tile adhesive of the present invention. The cooperation between the early-strength agent and the graded aggregate can significantly improve the early hydration rate and early strength of the early-strength tile adhesive of the present invention without using a large amount of cement and early-strength agent, enabling the tile adhesive to have a relatively high bonding strength when the prefabricated building is transported out of the factory, reducing problems such as tile shedding, displacement, or hollowing. Detailed Embodiments

[0029] In order to better explain the present invention for easy understanding, the present invention will be described in detail below through specific embodiments.

[0030] The present invention provides an early-strength tile adhesive applicable to prefabricated buildings. By weight, the raw materials of the early-strength tile adhesive include: 20 - 50 parts of cement, 4 - 12 parts of mineral admixture, 50 - 95 parts of graded aggregate, 1 - 6 parts of rubber powder, 0.01 - 0.1 part of early-strength agent, 0.01 - 0.05 part of thickener, 0.03 - 0.12 part of superabsorbent resin, 0.3 - 2 parts of chopped fiber, and 20 - 65 parts of water.

[0031] The particle size of the particles in the graded aggregate is between 2.36 mm and 0.020 mm; in the graded aggregate, the content of particles with a particle size greater than 0.080 mm does not exceed 80%, the content of particles with a particle size greater than 0.170 mm is not less than 58%, and the content of particles with a particle size greater than 0.800 mm does not exceed 38%.

[0032] The superabsorbent resin can absorb 100 - 400 times its own weight of water. The particle size of the superabsorbent resin is 180 μm - 420 μm.

[0033] The early strength agent includes at least one of nitrate early strength agents, carbonate early strength agents, organic early strength agents, and sulfate early strength agents.

[0034] Preferably, by weight, the raw materials of the early strength tile adhesive include: 30 - 45 parts of cement, 6 - 10 parts of mineral admixture, 60 - 80 parts of graded aggregate, 2 - 4 parts of rubber powder, 0.02 - 0.06 parts of early strength agent, 0.01 - 0.02 parts of thickener, 0.05 - 0.1 parts of superabsorbent resin, 0.5 - 1 part of chopped fiber, and 25 - 55 parts of water.

[0035] The mineral admixture is a mineral admixture made from clay minerals as raw materials.

[0036] In the graded aggregate, the content of particles with a particle size of 0.020 mm - 0.080 mm is 20 - 28 wt%, the content of particles with a particle size of 0.080 mm - 0.170 mm is 10 - 14 wt%, the content of particles with a particle size of 0.170 mm - 0.800 mm is 25 - 35 wt%, and the content of particles with a particle size of 0.800 mm - 2.36 mm is 30 - 38 wt%.

[0037] The superabsorbent resin can absorb 250 - 350 times its own weight of water; the particle size of the superabsorbent resin is 220 μm - 380 μm.

[0038] The early strength agent includes nitrate early strength agents, carbonate early strength agents, and organic early strength agents. The cement is at least one of portland cement and ordinary portland cement.

[0039] Among them, since the formula of the early strength tile adhesive of the present invention is added with an early strength agent, it can improve the hydration rate of accelerating cement hydration of the early strength tile adhesive of the present invention, and improve the development rate of the early strength and bonding strength of the early strength tile adhesive.

[0040] It should be noted that the early strength agent in the early strength tile adhesive of the present invention can be nitrate early strength agents, carbonate early strength agents, organic early strength agents, and sulfate early strength agents, such as calcium formate, lithium carbonate, lithium nitrate, calcium nitrate, and sodium sulfate and other early strength agents, but early strength agents containing chloride ions, such as calcium chloride and other chloride salt types of early strength agents, cannot be used. Chloride ions may cause a significant decrease in the water absorption rate and durability of the superabsorbent resin, and may cause corrosion to the steel bars in the wall. The early strength agent used in the early strength tile adhesive of the present invention can also be a CSH (calcium silicate hydrate) nucleating agent, but the cost is relatively high and it is generally not used.

[0041] The present invention also adopts a graded aggregate formed by mixing fine aggregates with multiple particle size ranges and a large amount of fine powder with smaller particle sizes. It can improve the density, fluidity and bonding strength of the early-strength tile adhesive of the present invention through the cooperation between particles of different particle sizes, and reduce its shrinkage rate and cracking risk. At the same time, the graded aggregate can also cooperate with the early-strengthening agent. By the dense structure of the graded aggregate, the structural defects generated during the accumulation of the aggregate are reduced, the water evaporation is reduced, and an efficient reaction environment is created for the early-strengthening agent, making the early-strengthening agent more evenly dispersed. The hydration products generated rapidly under the action of the early-strengthening agent can quickly fill the gaps in the graded aggregate, further improving the development speed of the early strength of the early-strength tile adhesive of the present invention. The cooperation between the early-strengthening agent and the graded aggregate can greatly improve the early hydration rate and early strength of the early-strength tile adhesive of the present invention without using a large amount of cement and early-strengthening agent, so that when the prefabricated building is transported out of the factory, the tile adhesive has a high bonding strength, reducing the occurrence of problems such as tile shedding, displacement or hollowing.

[0042] Specifically, the particle size range of the graded aggregate of the present invention includes four ranges: extremely fine particles (0.020 mm - 0.080 mm, accounting for 20 - 28 wt%), fine particles (0.080 mm - 0.170 mm, accounting for 10 - 14 wt%), medium particles (0.170 mm - 0.800 mm, accounting for 25 - 35 wt%), and coarse particles (0.800 mm - 2.36 mm, accounting for 30 - 38 wt%).

[0043] Among them, the extremely fine particles have a filling effect, can fill the tiny pores in the cement paste, strengthen the interfacial bonding of the cement hydration products, improve the density, and enhance the bonding strength between the early-strength tile adhesive of the present invention and the tile and the base surface (after the tile is pasted, a three-layer structure of tile - tile adhesive layer - base surface is formed, and the base surface is the wall surface, bottom surface or other surfaces where the tile is to be pasted), reducing the occurrence of problems such as shrinkage and hollowing. The extremely fine particles also have the functions of water retention and lubrication, can adjust the open time of the early-strength tile adhesive of the present invention, improve the lubricity of its paste, and improve its construction effect. If the content of the extremely fine particles is too high, the water demand of the tile adhesive will increase significantly, and it will lead to a decrease in strength and shrinkage cracking.

[0044] The fine particles play a transitional role, can optimize the fluidity of the early-strength tile adhesive of the present invention, reduce the frictional resistance inside its paste, improve its scraping effect, and improve its plasticity. The fine particles can also provide local mechanical support to prevent the excessive aggregation of the extremely fine particles to form weak areas. If the content of the fine particles is too low, the grading of the aggregate may be discontinuous, which may lead to poor fluidity of the early-strength tile adhesive; if the content of the fine particles is too high, the density of the early-strength tile adhesive may be reduced.

[0045] Medium particles exist as the main skeleton structure, which can improve the compressive strength and impact resistance of the early-strength tile adhesive of the present invention. Medium particles can also cooperate with fine particles and ultra-fine particles to form a dense packing structure, reduce drying shrinkage through a stable particle gradation, control the shrinkage rate of the early-strength tile adhesive of the present invention, reduce the porosity after its curing, and avoid the hollowing and falling off of tiles. Insufficient content of medium particles will lead to loose skeleton and a decrease in the impact resistance and strength of the tile adhesive after curing.

[0046] Coarse particles play a role in macroscopic skeleton support. They can provide rigid support to resist external loads and deformations. In the support function of coarse particles, an important point is that since the particle size of coarse particles itself is much larger than the particle size of the superabsorbent resin used in the early-strength tile adhesive of the present invention, even after the superabsorbent resin absorbs water and swells, its particle size will not exceed the size of coarse particles, which will not affect the support effect of coarse particles, can reduce the influence of the volume change of the superabsorbent resin on the internal stress of the early-strength tile adhesive of the present invention, avoid the influence of the superabsorbent resin on the contact between the early-strength tile adhesive of the present invention and the tile and the base surface, and prevent the formation of local bonding weakening. In addition, since the thermal expansion coefficient of coarse particles is generally lower than that of cement itself, it can also reduce the influence of problems such as cement expansion and contraction caused by thermal effects such as hydration heat, and reduce the cracking risk caused by temperature changes, especially the risk caused by problems such as expansion and contraction generated during the cement hydration process. If the content of coarse particles is too low or the particle size is too small, sufficient support effect cannot be achieved, which may cause the superabsorbent resin to squeeze the tile or the base surface, resulting in a decrease in the local bonding ability of the early-strength tile adhesive of the present invention and excessive internal stress changes, and then leading to cracking or hollowing of the adhesive layer formed after the tile adhesive cures. If the content of coarse particles is too high or the particle size is too large, it will reduce the uniformity of the thickness of the tile adhesive layer formed after the early-strength tile adhesive cures, resulting in uneven tile pasting and prone to problems such as hollowing.

[0047] During use, the sum of the weight fractions of ultra-fine particles, fine particles, medium particles, and coarse particles is not less than 99 wt%. A part of the particles with a particle size less than 0.020 mm is allowed to exist in the graded aggregate, but its weight fraction should not exceed 1 wt%. The particles with a particle size exceeding 2.36 mm should be screened out, otherwise it is easy to cause problems such as stress concentration and defects at the cement hydration interface.

[0048] The early-strength tile adhesive of the present invention is also added with a superabsorbent resin (SAP) that cooperates with the early-strength agent and the graded aggregate. The superabsorbent resin is a general term for a class of polymer compounds. These polymer compounds have a special three-dimensional cross-linked structure, can absorb and store a large amount of water in their structure, and have good water storage and water retention capabilities.

[0049] Superabsorbent resins can control the rate at which free water in tile adhesives participates in the cement hydration reaction. After adding superabsorbent resins to early-strength tile adhesives, the water absorbed by them can stably release the stored free water when the external free water is largely consumed during cement hydration.

[0050] Specifically, when preparing the early-strength tile adhesive of the present invention, the superabsorbent resin can absorb and store a large amount of free water in the raw materials. The free water not stored by the superabsorbent resin will undergo a vigorous hydration reaction with cement under the action of the early-strength agent and graded aggregate, that is, the early-strength tile adhesive of the present invention undergoes rapid hydration in the early stage to obtain a relatively high early strength. Rapid hydration requires a large amount of free water. When the free water not stored by the superabsorbent resin is largely consumed, the continued hydration of the tile adhesive depends on the free water stored in the superabsorbent resin. At this time, the superabsorbent resin will stably and slowly release the stored free water, maintain the humidity inside the early-strength tile adhesive within a certain range, delay the rate of contact between cement particles and free water, reduce the hydration rate, extend the hydration time, enable the cement to undergo continuous slow hydration, improve the durability and bonding strength of the tile adhesive, make its long-term strength higher, durability stronger, and have a longer service life. Moreover, this slow hydration can also endow the tile adhesive with a certain self-healing ability. When disturbances during transportation cause defects such as microcracks in the tile adhesive layer, it can be compensated and repaired to a certain extent.

[0051] At the same time, after uniformly mixing the superabsorbent resin into the tile adhesive, its property of releasing water and maintaining the humidity inside the tile adhesive can also effectively reduce the pressure on the capillary walls formed during cement hydration, reduce the shrinkage during cement hydration, especially reduce the early shrinkage of the early-strength tile adhesive of the present invention, avoid cracks in the tile adhesive layer formed after use due to excessive or overly concentrated shrinkage, improve the bonding strength of the early-strength tile adhesive of the present invention, and avoid bonding failure.

[0052] In addition, since the early-strength tile adhesive of the present invention has a relatively fast development rate of early strength under the action of the early-strength agent and graded aggregate, it will generate a relatively high hydration heat. The superabsorbent resin storing a large amount of water can also disperse the heat release and adjust the temperature gradient in the early-strength tile adhesive by releasing water and regulating water evaporation, reduce the influence of the early hydration heat of the early-strength tile adhesive, and avoid problems such as bonding failure or cracks caused by excessive or overly concentrated hydration heat of the early-strength tile adhesive.

[0053] It should be noted that the addition amount and water absorption rate of the superabsorbent resin need to be strictly controlled. If the addition amount of the superabsorbent resin is too high and the water absorption rate is too large, it will absorb a large amount of free water, causing the early-strength tile adhesive to develop slowly during the early hydration process and unable to undergo a hydration reaction with a large amount of free water quickly, resulting in poor strength development and inability to complete bonding. When the addition amount of the superabsorbent resin is too low and the water absorption rate is too small, the superabsorbent resin does not have good water storage and retention ability, which will lead to a decline in the later performance of the early-strength tile adhesive; it may also cause the hydration heat of the early-strength tile adhesive to be too high or too concentrated, resulting in a large shrinkage, causing cracks in the bonding layer of the early-strength tile adhesive, and a decrease in the flatness and bonding strength of the bonding layer. In the early-strength tile adhesive of the present invention, the water absorption rate of the superabsorbent resin is controlled to be able to absorb 100-400 times its own weight of water, and the addition amount is 0.03-0.12 parts, preferably the water absorption rate is able to absorb 250-350 times its own weight of water, and the addition amount is 0.05-0.1 parts. Within this range, the water storage and retention ability of the superabsorbent resin can be effectively controlled, the effect of the superabsorbent resin can be ensured to be stable, and a certain tolerance can be provided for the preparation process of the tile adhesive of the present invention to avoid the situation of excessive superabsorbent resin.

[0054] The particle size range of the superabsorbent resin also needs to be controlled. If the particle size is too small, the water loss rate of the superabsorbent resin will be too fast, unable to effectively control the strength development rate of the early-strength tile adhesive, and the control effect on the hydration heat of the early-strength tile adhesive is also relatively low. If the particle size is too large, it may cause large pores to be generated after the superabsorbent resin loses water, resulting in problems such as a decrease in the bonding strength and a reduction in the density of the early-strength tile adhesive. In the early-strength tile adhesive of the present invention, the particle size of the superabsorbent resin is controlled to be 180μm-420μm, preferably 220μm-380μm. Controlling the particle size of the superabsorbent resin within this range can not only obtain a more appropriate water loss rate of the superabsorbent resin, effectively control the hydration heat and shrinkage during the hydration process, but also form a stable microporous structure using the space formed after the superabsorbent resin loses water and shrinks, improving the seismic resistance and sound insulation ability of the tile adhesive, and further avoiding the influence of the disturbance during the transportation and hoisting of the prefabricated building on the early-strength tile adhesive of the present invention, reducing delamination and cracking.

[0055] Mineral admixtures are also added to the early-strength tile adhesive of the present invention. Through the filling effect and pozzolanic effect, they can improve the durability and strength of the early-strength tile adhesive, reduce the occurrence of cracks, and together with the superabsorbent resin, improve the maintenance time of the working performance of the early-strength tile adhesive of the present invention. In addition, the mineral admixture made of clay minerals also has good plasticity and viscosity. It can not only improve the durability and strength of the early-strength tile adhesive of the present invention, but also, on this basis, increase the plasticity, thixotropy, adhesion and cohesion of the early-strength tile adhesive of the present invention, and improve its construction performance, especially the construction performance during the spreading and tile laying processes, making its fluidity increase when a shear force is applied (during stirring), and it can maintain a relatively stable state when in a static state, and enabling the tiles to be stably adhered to the base surface through the early-strength tile adhesive of the present invention. The addition of the mineral admixture made of clay minerals can also reduce the impact of the addition of the superabsorbent resin on the construction performance of the early-strength tile adhesive of the present invention, and avoid situations such as tile slippage. At the same time, the mineral admixture made of clay minerals also has good water retention and swelling effects. Its water retention can cooperate with the superabsorbent resin to synergistically regulate moisture and further reduce drying shrinkage; its swelling effect can also fill the cracks generated by possible shrinkage, and improve the density and bonding strength of the early-strength tile adhesive of the present invention. In addition, as a natural material, the mineral admixture made of clay minerals is also environmentally friendly when in use.

[0056] Preferably, the superabsorbent resin includes at least one of sodium polyacrylate, polyacrylamide, polyvinyl alcohol grafted acrylate, cellulose grafted acrylate, and acrylate-acrylamide copolymer. The synthesis of these materials is relatively mature, the control of the water absorption rate of the superabsorbent resin is relatively accurate, and it is not easy to have synthesis errors. Moreover, since a too high water absorption rate is not required, the cost of these materials is relatively low. In actual use, the superabsorbent resin used in the early-strength tile adhesive of the present invention is not limited to the above types, and other types of superabsorbent resins can also be used, as long as the requirements for particle size and water absorption rate are met, the related processes are mature, and it can be stably supplied for use.

[0057] More preferably, the superabsorbent resin includes sodium polyacrylate, polyvinyl alcohol grafted acrylate, and acrylate-acrylamide copolymer.

[0058] Preferably, the cement includes at least one of P.Ⅱ.52.5, P.Ⅱ.42.5, P.Ⅱ.52.5R, P.Ⅱ.42.5R, P.O.42.5, and P.O.52.5. The particle size of the cement does not exceed 80μm; the specific surface area of the cement is 350 - 450 m2 / kg.

[0059] It should be noted that the selection of the above cement grade is made by the early-strength tile adhesive of the present invention considering factors such as early strength and open time during normal operation. It does not mean that the early-strength tile adhesive of the present invention cannot use other grades or types of cement. For example, when higher early strength and later durability are required, cements with higher strength such as P.Ⅱ.62.5 and P.Ⅱ.62.5R, which have higher early strength, can be selected. However, this will result in a shorter open time of the early-strength tile adhesive, and it needs to be used as soon as possible after being stirred to obtain the early-strength tile adhesive.

[0060] Preferably, the specific surface area of the mineral admixture is 22 - 28 m 2 / g. It is necessary to control the specific surface area of the mineral admixture to ensure its pozzolanic activity and water retention capacity, and improve the later strength and fluidity of the early-strength tile adhesive of the present invention.

[0061] Preferably, the mineral admixture includes fly ash, silica fume, ultra-fine slag, and mineral admixtures made mainly from clay minerals.

[0062] More preferably, the mineral admixture is a mineral admixture made from clay minerals, preferably at least one of kaolin powder, metakaolin powder, bentonite powder, sepiolite powder, and illite powder. Among them, kaolin powder, bentonite powder, sepiolite powder, and illite powder are all made by crushing and processing natural clay minerals. Metakaolin powder is made by high-temperature calcination processing of kaolin powder. Considering cost and scope of application, the mineral admixture is preferably at least one of kaolin powder, metakaolin powder, and bentonite powder. If the prefabricated building module needs to be used in a relatively complex chemical environment, preferably, the mineral admixture is compounded with at least one of kaolin powder, metakaolin powder, and bentonite powder and at least one of sepiolite powder and illite powder. Sepiolite powder and illite powder have a strong adsorption capacity for ions.

[0063] Preferably, the graded aggregate includes at least one of river sand, lake sand, mountain sand, quartz sand, granite sand, basalt sand, and recycled sand. It is preferably quartz sand, granite sand, and basalt sand. Among them, quartz sand, granite sand, and basalt sand are all manufactured sand, and their particle size ranges are easy to control and the impurities are less.

[0064] Preferably, the rubber powder includes at least one of ethylene-vinyl acetate copolymer rubber powder, acrylate rubber powder, polyvinyl acetate rubber powder, styrene-butadiene rubber powder, polyvinyl alcohol rubber powder, polyurethane rubber powder, and starch ether rubber powder. The rubber powder is selected according to the design requirements.

[0065] Preferably, the chopped fibers include polypropylene fibers, polyethylene fibers, polyvinyl alcohol fibers, and wood fibers.

[0066] More preferably, the chopped fibers are wood fibers. The length of the wood fibers is 4-8 mm, and the diameter does not exceed 40 μm. The good flexibility and dispersibility of the wood fibers can form a three-dimensional network structure inside the tile adhesive, further enhancing the crack resistance and anti-slip property of the early-strength tile adhesive of the present invention, and reducing the phenomenon of hollowing. The wood fibers also have a certain water absorption and water storage capacity, which can further enhance the durability and construction performance of the early-strength tile adhesive of the present invention. Among them, the length of the wood fibers cannot be too long, and the diameter cannot be too high, otherwise it will affect the working properties such as the fluidity and plasticity of the early-strength tile adhesive of the present invention. When the length is too short, its performance is insufficient, which will lead to a decrease in the crack resistance and anti-slip property of the early-strength tile adhesive of the present invention.

[0067] Preferably, the early-strength agent is at least one of calcium formate, sodium formate, lithium nitrate, calcium nitrate, calcium sulfate, and sodium sulfate. Among them, organic early-strength agents, carbonate early-strength agents, and nitrate early-strength agents are preferably selected. Although sulfate early-strength agents can meet the early-strength effect, they may have a certain impact on the water absorption rate and durability of the superabsorbent resin, and the dosage needs to be strictly controlled during use.

[0068] More preferably, the thickener is a cellulose-based thickener. The cellulose-based thickener includes at least one of hydroxypropyl methylcellulose, methylcellulose, hydroxymethylcellulose, and hydroxyethylcellulose; the viscosity of the cellulose-based thickener is 90,000-110,000 Pa·s, preferably 100,000 Pa·s. By adding a thickener, the viscosity of the early-strength tile adhesive of the present invention is increased, and its adhesion is improved. In addition, the cellulose-based thickener can further crosslink with the rubber powder and wood fibers to improve the crack resistance effect of the early-strength tile adhesive of the present invention.

[0069] The present invention also provides a preparation method of an early-strength tile adhesive, which is characterized by including the following steps:

[0070] S1: Prepare the corresponding raw materials according to the parts of the raw materials of the early-strength tile adhesive applicable to prefabricated buildings of the present invention, and mix the superabsorbent resin with 10%-20% of the water in the raw materials to obtain a superabsorbent resin gel;

[0071] S2: Mix and stir the early-strength agent, thickener with the remaining 80%-90% of the water in the raw materials to obtain a wet material;

[0072] S3: Mix and stir cement, mineral admixture, graded aggregate, rubber powder, and wood fibers to obtain a dry material;

[0073] S4: Mix and stir the superabsorbent resin gel, dry material, and wet material to obtain an early-strength tile adhesive.

[0074] Among them, in step S1, the superabsorbent resin is premixed with a certain amount of water to allow the superabsorbent resin to absorb water in advance and convert from a solid state to a gel state. It is necessary to avoid directly mixing the dry superabsorbent resin with dry and wet materials to prevent the superabsorbent resin from competing with cement for free water and avoid a decrease in the early hydration rate of the early-strength tile adhesive. After the superabsorbent resin has completely absorbed the water mixed with it or the superabsorbent resin no longer absorbs water, a superabsorbent resin gel is obtained. If there is water that the superabsorbent resin has not absorbed completely, it is added to step S4 together with the superabsorbent resin gel.

[0075] In step S2, premixing the early-strength agent, thickener and water in advance helps the rapid mixing of the early-strength agent and thickener with the dry materials in the subsequent process.

[0076] In step S3, cement, mineral admixture, graded aggregate, rubber powder and wood fiber are mixed and stirred to obtain dry materials, which can reduce the time required for these to be completely mixed with the wet materials and reduce the loss of the open time of the early-strength tile adhesive.

[0077] In step S4, the stirring speed should not be too high to prevent a large number of ruptures of the superabsorbent resin gel, resulting in a decrease in its water absorption effect and failure to achieve the effect of storing and retaining water.

[0078] Specifically, in step S2, when mixing and stirring the early-strength agent, thickener and water, the stirring speed is 300 - 500 rpm and the stirring time is 1 - 3 min (min: minute).

[0079] In step S3, when mixing and stirring cement, mineral admixture, graded aggregate, rubber powder and wood fiber, the stirring speed is 300 - 500 rpm (rpm: revolutions per minute) and the stirring time is 1 - 2 min.

[0080] In step S4, when mixing and stirring the superabsorbent resin gel, dry materials and wet materials, the stirring speed is 150 - 250 rpm and the stirring time is 2 - 4 min.

[0081] To better understand the above technical solution, the exemplary embodiments of the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to convey the scope of the present invention completely to those skilled in the art.

[0082] First, it should be noted that due to errors in aspects such as production processes, chemical composition characteristics, particle size distribution, weight control standards, and test conditions of the actually produced and sold superabsorbent resins, even for products of the same batch, the water absorption rate of the superabsorbent resin (the water absorption rate is the number of times the superabsorbent resin can absorb water of its own weight) will have certain fluctuations. For example, if the selected superabsorbent resin can absorb 300 times its own weight of water, that is, when the water absorption rate is 300, the actual water absorption rate range of the superabsorbent resin may fluctuate between 285 - 315, that is, there will be certain positive and negative errors, generally ±5% - ±10%. Redundancy control needs to be noted during use. At the same time, similar to the water absorption rate, the particle size of the superabsorbent resin itself will also have a certain gradient distribution. Of course, if precise control is required, the superabsorbent resin with accurate parameters such as particle size and water absorption rate can also be selected by means of secondary classification and sieving during use, but at this time, material costs and time costs will increase significantly, and it is only applicable to the experimental environment. To ensure the accuracy of the description of the present invention, the particle size of the superabsorbent resin mentioned in the embodiments of the present invention appears in the form of a particle size range, and the water absorption rate appears in the form of the average value of the fluctuation range (that is, before use, multiple random superabsorbent resin samples are taken, and after they are saturated with water respectively, the average value of the water absorption rates of multiple samples is calculated).

[0083] Example 1

[0084] This example provides an early - strength tile adhesive applicable to prefabricated buildings. By weight, its raw materials include: 40 parts of cement, 8 parts of metakaolin powder, 70 parts of quartz sand, 3 parts of ethylene - vinyl acetate copolymer powder, 0.04 parts of calcium formate, 0.01 parts of hydroxypropyl methylcellulose, 0.05 parts of sodium polyacrylate, 0.8 parts of wood fiber, and 30 parts of water.

[0085] Among them, the cement grade is P.Ⅱ52.5. In the quartz sand, the content of particles with a particle size of 0.020 mm - 0.080 mm is 25 wt%, the content of particles with a particle size of 0.080 mm - 0.170 mm is 12 wt%, the content of particles with a particle size of 0.170 mm - 0.800 mm is 30 wt%, and the content of particles with a particle size of 0.800 mm - 2.36 mm is 33 wt%.

[0086] Sodium polyacrylate can absorb 300 times its own weight of water; the particle size of the superabsorbent resin is 220 μm - 380 μm.

[0087] This example also provides a preparation method of an early - strength tile adhesive applicable to prefabricated buildings, including the following steps:

[0088] S1: Prepare the raw materials, and mix sodium polyacrylate with 6 parts of water to obtain sodium polyacrylate gel.

[0089] S2: Mix calcium formate, hydroxypropyl methylcellulose with the remaining 24 parts of water and stir to obtain a wet material. Among them, the stirring speed is 400 rpm and the stirring time is 2 min.

[0090] S3: Mix cement, metakaolin powder, quartz sand, ethylene-vinyl acetate copolymer powder and wood fiber and stir to obtain a dry material. Among them, the stirring speed is 400 rpm and the stirring time is 1 min.

[0091] S4: Mix sodium polyacrylate gel, the dry material and the wet material and stir to obtain the early-strength tile adhesive of the present invention. Among them, the stirring speed is 200 rpm and the stirring time is 3 min.

[0092] After testing, the 1d (d: day) tensile bond strength of the obtained early-strength tile adhesive is 0.609 MPa, the 3d tensile bond strength is 1.215 MPa, the 3d drying shrinkage rate is 0.014%, and the tile hollowing rate after vibration simulation is 1.5%.

[0093] Among them, the test standard for the tensile bond strength of the tile adhesive is carried out according to JC / T 547-2017 "Ceramic Tile Adhesives", and the test standard for the drying shrinkage rate is carried out according to GB / T 29417-2012 "Test Methods for Drying Shrinkage and Cracking Properties of Mortar and Concrete".

[0094] Vibration simulation is carried out using an electric vibration table or a special vibration testing machine. The simulation time is 4 - 6 hours, including the following road condition simulation stages:

[0095] The first stage, highway (low-frequency vibration, using a random vibration table), accounts for 60% of the test time, and the test conditions are: PSD (Power Spectral Density) 0.01 - 0.03 g2 / Hz. (g is the unit of gravitational acceleration; Hz is the unit of frequency)

[0096] The second stage, ordinary road (medium-frequency vibration, using a random vibration table), accounts for 30% of the test time, and the test conditions are: PSD 0.03 - 0.06 g2 / Hz.

[0097] The third stage, bumpy road and hoisting (high-frequency impact, using a sine vibration table), accounts for 10% of the test time, and the test conditions are: 2.5 g@10 Hz.

[0098] After vibration simulation, the hollowing rate test is carried out. The hollowing rate test mainly taps the four corners and the center of the tile with a hollowing hammer, and judges the hollowing position by listening to the sound. If there are two hollows among the four corners and the center, it is considered that the tile is hollow, and then the proportion of the area of the hollow tiles in the total area of the tiles is calculated to obtain the hollowing rate.

[0099] Example 2

[0100] This embodiment provides an early-strength tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, by weight, its raw materials include: 45 parts of cement, 10 parts of metakaolin, 80 parts of quartz sand, 2 parts of ethylene-vinyl acetate copolymer powder, 0.05 part of calcium formate, 0.02 part of hydroxypropyl methylcellulose, 0.07 part of sodium polyacrylate, 1 part of wood fiber, and 35 parts of water.

[0101] In the quartz sand, the content of particles with a particle size of 0.020 mm - 0.080 mm is 27 wt%, the content of particles with a particle size of 0.080 mm - 0.170 mm is 11 wt%, the content of particles with a particle size of 0.170 mm - 0.800 mm is 27 wt%, and the content of particles with a particle size of 0.800 mm - 2.36 mm is 35 wt%.

[0102] After testing, the 1d tensile bond strength of the obtained early-strength tile adhesive is 0.692 MPa, the 3d tensile bond strength is 1.191 MPa, the 3d dry shrinkage rate is 0.014%, and the tile hollowing rate after vibration simulation is 1.4%. The testing method refers to Embodiment 1.

[0103] Embodiment 3

[0104] This embodiment provides an early-strength tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, by weight, its raw materials include: 30 parts of cement, 6 parts of metakaolin, 65 parts of quartz sand, 2 parts of ethylene-vinyl acetate copolymer powder, 0.05 part of calcium formate, 0.02 part of hydroxypropyl methylcellulose, 0.1 part of sodium polyacrylate, 1 part of wood fiber, and 35 parts of water.

[0105] In the quartz sand, the content of particles with a particle size of 0.020 mm - 0.080 mm is 21 wt%, the content of particles with a particle size of 0.080 mm - 0.170 mm is 10 wt%, the content of particles with a particle size of 0.170 mm - 0.800 mm is 32 wt%, and the content of particles with a particle size of 0.800 mm - 2.36 mm is 37 wt%.

[0106] After testing, the 1d tensile bond strength of the obtained early-strength tile adhesive is 0.557 MPa, the 3d tensile bond strength is 1.059 MPa, the 3d dry shrinkage rate is 0.015%, and the tile hollowing rate after vibration simulation is 1.5%. The testing method refers to Embodiment 1.

[0107] Embodiment 4

[0108] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 2 is that in this embodiment, by weight, there are 45 parts of cement, 10 parts of metakaolin powder, 70 parts of quartz sand, 2 parts of ethylene-vinyl acetate copolymer powder, 2 parts of polyurethane powder, 0.01 part of lithium nitrate, 0.04 part of calcium formate, 0.02 part of hydroxypropyl methylcellulose, 0.07 part of sodium polyacrylate, 1 part of wood fiber, and 40 parts of water.

[0109] After testing, the 1d tensile bond strength of the obtained early-strength ceramic tile adhesive is 0.736 MPa, the 3d tensile bond strength is 1.341 MPa, the 3d drying shrinkage rate is 0.014%, and the tile hollowing rate after vibration simulation is 1.2%. The testing method refers to Embodiment 1.

[0110] Embodiment 5

[0111] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, by weight, its raw materials include: 40 parts of cement, 8 parts of kaolin powder, 70 parts of quartz sand, 4 parts of ethylene-vinyl acetate copolymer powder, 2 parts of polyurethane powder, 0.08 part of calcium formate, 0.04 part of hydroxypropyl methylcellulose, 0.04 part of sodium polyacrylate, 0.05 part of acrylic acid-acrylamide copolymer, 1.5 parts of wood fiber, and 55 parts of water.

[0112] After testing, the 1d tensile bond strength of the obtained early-strength ceramic tile adhesive is 0.887 MPa, the 3d tensile bond strength is 1.396 MPa, the 3d drying shrinkage rate is 0.015%, and the tile hollowing rate after vibration simulation is 1.4%. The testing method refers to Embodiment 1.

[0113] Embodiment 6

[0114] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, sodium polyacrylate can absorb 250 times its own weight of water.

[0115] After testing, the 1d tensile bond strength of the obtained early-strength ceramic tile adhesive is 0.624 MPa, the 3d tensile bond strength is 1.307 MPa, the 3d drying shrinkage rate is 0.015%, and the tile hollowing rate after vibration simulation is 1.6%. The testing method refers to Embodiment 1.

[0116] Embodiment 7

[0117] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, sodium polyacrylate can absorb 350 times its own weight of water.

[0118] After testing, the 1-day tensile bond strength of the obtained early-strength tile adhesive is 0.603 MPa, the 3-day tensile bond strength is 1.139 MPa, the 3-day drying shrinkage rate is 0.013%, and the tile hollowing rate after vibration simulation is 1.4%. The testing method refers to Example 1.

[0119] Example 8

[0120] This example provides an early-strength tile adhesive applicable to prefabricated buildings. The difference from Example 1 is that in this example, the particle size of sodium polyacrylate is 300 - 420 μm.

[0121] After testing, the 1-day tensile bond strength of the obtained early-strength tile adhesive is 0.611 MPa, the 3-day tensile bond strength is 1.203 MPa, the 3-day drying shrinkage rate is 0.013%, and the tile hollowing rate after vibration simulation is 1.4%. The testing method refers to Example 1.

[0122] Example 9

[0123] This example provides an early-strength tile adhesive applicable to prefabricated buildings. The difference from Example 1 is that in this example, the particle size of sodium polyacrylate is 180 - 300 μm.

[0124] After testing, the 1-day tensile bond strength of the obtained early-strength tile adhesive is 0.627 MPa, the 3-day tensile bond strength is 1.243 MPa, the 3-day drying shrinkage rate is 0.015%, and the tile hollowing rate after vibration simulation is 1.6%. The testing method refers to Example 1.

[0125] Example 10

[0126] This example provides an early-strength tile adhesive applicable to prefabricated buildings. The difference from Example 1 is that in this example, by weight, its raw materials include: 40 parts of cement, 8 parts of ultra-fine slag, 50 parts of quartz sand, 20 parts of granite sand, 2 parts of ethylene-vinyl acetate copolymer powder, 2 parts of polyurethane powder, 0.03 parts of calcium formate, 0.03 parts of lithium nitrate, 0.02 parts of methyl cellulose, 0.05 parts of sodium polyacrylate, 0.05 parts of polyacrylamide, 0.5 parts of polypropylene fiber, 0.5 parts of wood fiber, and 55 parts of water.

[0127] After testing, the 1-day tensile bond strength of the obtained early-strength tile adhesive is 0.924 MPa, the 3-day tensile bond strength is 1.386 MPa, the 3-day drying shrinkage rate is 0.015%, and the tile hollowing rate after vibration simulation is 1.3%. The testing method refers to Example 1.

[0128] Example 11

[0129] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, the grade of the cement is P.Ⅱ.52.5R.

[0130] After testing, the 1d tensile bond strength of the obtained early-strength ceramic tile adhesive is 1.424 MPa, the 3d tensile bond strength is 2.337 MPa, the 3d drying shrinkage rate is 0.016%, and the tile hollowing rate after vibration simulation is 0.9%. The testing method refers to Embodiment 1.

[0131] Embodiment 12

[0132] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 3 is that in this embodiment, by weight, its raw materials include: 25 parts of cement, 8 parts of kaolin, 55 parts of quartz sand, 2 parts of ethylene-vinyl acetate copolymer powder, 1 part of polyurethane powder, 0.06 part of lithium nitrate, 0.03 part of calcium nitrate, 0.04 part of methyl cellulose, 0.05 part of sodium polyacrylate, 0.05 part of polyacrylamide, 0.5 part of polypropylene fiber, 0.5 part of wood fiber, and 35 parts of water.

[0133] After testing, the 1d tensile bond strength of the obtained early-strength ceramic tile adhesive is 0.812 MPa, the 3d tensile bond strength is 1.197 MPa, the 3d drying shrinkage rate is 0.014%, and the tile hollowing rate after vibration simulation is 1.3%. The testing method refers to Embodiment 1.

[0134] Comparative Example 1

[0135] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, sodium polyacrylate is not used.

[0136] After testing, the 1d tensile bond strength of the obtained ceramic tile adhesive is 0.685 MPa, the 3d tensile bond strength is 1.259 MPa, the 3d drying shrinkage rate is 0.048%, and the tile hollowing rate after vibration simulation is 23%. The testing method refers to Embodiment 1.

[0137] Comparative Example 2

[0138] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, the number of parts of sodium polyacrylate is 0.2 part.

[0139] After the ceramic tile adhesive is stirred, it cannot be formed and cannot be used.

[0140] Comparative Example 3

[0141] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, the particle size of the superabsorbent resin is 480 - 580 μm.

[0142] After testing, the 1-day tensile bond strength of the obtained early-strength ceramic tile adhesive is 0.615 MPa, the 3-day tensile bond strength is 1.105 MPa, the 3-day drying shrinkage rate is 0.012%, and the tile hollowing rate after vibration simulation is 15%. The testing method refers to Embodiment 1.

[0143] Comparative Example 4

[0144] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, the particle size of the superabsorbent resin is 50 - 150 μm.

[0145] After testing, the 1-day tensile bond strength of the obtained early-strength ceramic tile adhesive is 0.726 MPa, the 3-day tensile bond strength is 1.473 MPa, the 3-day drying shrinkage rate is 0.031%, and the tile hollowing rate after vibration simulation is 14%. The testing method refers to Embodiment 1.

[0146] Comparative Example 5

[0147] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, sodium polyacrylate can absorb 50 times its own weight of water.

[0148] After testing, the 1-day tensile bond strength of the obtained early-strength ceramic tile adhesive is 0.642 MPa, the 3-day tensile bond strength is 1.315 MPa, the 3-day drying shrinkage rate is 0.037%, and the tile hollowing rate after vibration simulation is 18%. The testing method refers to Embodiment 1.

[0149] Comparative Example 6

[0150] This embodiment provides an early-strength ceramic tile adhesive applicable to prefabricated buildings. The difference from Embodiment 1 is that in this embodiment, ordinary aggregates are used to replace graded aggregates. Among the ordinary aggregates, the mass fraction of particles with a particle size of 0.100 mm - 0.400 mm is 92 wt%, and the mass fraction of particles with a particle size of 0.010 - 0.015 is 8 wt%.

[0151] After testing, the 1-day tensile bond strength of the obtained ceramic tile adhesive is 0.563 MPa, the 3-day tensile bond strength is 0.786 MPa, the 3-day drying shrinkage rate is 0.035%, and the tile hollowing rate after vibration simulation is 25%. The testing method refers to Embodiment 1.

[0152] According to the data of Example 1 and Comparative Example 1, it can be found that the addition of superabsorbent resin can significantly improve the seismic resistance of tile adhesive and reduce the phenomenon of tile hollowing. In Comparative Example 1, although a hardening accelerator was used and a relatively high curing speed and early bonding strength could be obtained under the action of the hardening accelerator, since no superabsorbent resin was used, the early hydration heat was relatively high and the shrinkage was relatively large, resulting in possible bonding failure and a high tile hollowing rate.

[0153] According to the data of Example 1, Example 7 and Comparative Example 2, it can be found that in Example 7, due to the increase in the water absorption rate of the superabsorbent resin, the contact between cement and free water in the early stage decreased, and its early bonding strength decreased slightly. However, its shrinkage control was better, the possible cracks were fewer, and the hollowing rate decreased. In the comparative example, due to the excessive addition of superabsorbent resin, the superabsorbent resin competed with cement for free water, resulting in the unusability of the tile adhesive.

[0154] According to the data of Examples 1-3 and Comparative Example 6, it can be found that in Examples 1-3, the combination of graded aggregate and hardening accelerator can improve the early strength of the early-strength tile adhesive of the present invention and ensure uniform stress distribution in the tile adhesive layer, significantly reducing tile hollowing. In Comparative Example 6, since only two fine aggregates with relatively small particle sizes were combined with the hardening accelerator, although a certain early bonding strength could be obtained under the action of the hardening accelerator, it was impossible to break through the strength development speed of a single material in combination with the hardening accelerator, and a higher early-strength could not be obtained. Moreover, due to the lack of aggregate gradation, the stress was uneven, and the hollowing rate was relatively large after vibration.

[0155] According to the data of Example 1, Example 7 and Comparative Example 2, it can be found that in Example 7, due to the increase in the water absorption rate of the superabsorbent resin, the contact between cement and free water in the early stage decreased, and its early bonding strength decreased slightly. However, its shrinkage control was better, the possible cracks were fewer, and the hollowing rate decreased. In the comparative example, due to the excessive addition of superabsorbent resin, the superabsorbent resin competed with cement for free water, resulting in the unusability of the tile adhesive.

[0156] According to the data of Example 1, Example 8 and Comparative Example 3, it can be found that in Example 8, due to the relatively large particle size of the superabsorbent resin, its water loss rate was slower and the development of bonding strength at 3d was slower. In Comparative Example 3, due to the too large particle size of the superabsorbent resin, the bonding strength at 3d decreased further. Moreover, its too large particle size may also cause local bonding weakening at the contact parts between the early-strength tile adhesive and the tile and the base surface, resulting in further decrease in its bonding strength, poor bonding, and a relatively high hollowing rate after vibration.

[0157] From the data of Example 1, Example 9 and Comparative Example 4, it can be found that in Example 9, due to the use of superabsorbent resin with a smaller particle size, the control effect on the early bonding strength is relatively poor compared to Example 1, the bonding strength develops faster, and both the shrinkage rate and the hollowing rate increase. In Comparative Example 4, due to the too small particle size of the superabsorbent resin, the water loss rate is too fast. Although a relatively high early bonding strength can be achieved, the shrinkage rate and the hollowing rate cannot be controlled.

[0158] From the data of Example 1, Example 6 and Comparative Example 5, it can be found that in Example 6, due to the decrease in the water absorption rate of the superabsorbent resin, the free water in contact with the cement in the early stage of hydration increases, and its early bonding strength increases slightly, but the control ability of the cement shrinkage decreases slightly, and the hollowing rate increases. In Comparative Example 5, due to the too low water absorption rate, although the early bonding strength is high, the shrinkage cannot be controlled, and more cracks will occur, and the hollowing rate is significantly higher after vibration.

[0159] In summary, the early-strength tile adhesive of the present invention can solve the problems existing in the prior art, such as tile hollowing, falling off and displacement, which are likely to occur due to the disturbance during transportation and hoisting after using cement-based tile adhesive to lay tiles in prefabricated building modules.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An early-strength tile adhesive suitable for prefabricated buildings, characterized in that: The raw materials of the early-strength tile adhesive include, by weight: 20-50 parts of cement, 4-12 parts of mineral admixtures, 50-95 parts of graded aggregates, 1-6 parts of glue powder, 0.01-0.1 parts of early-strength agent, 0.01-0.05 parts of thickener, 0.03-0.12 parts of highly absorbent resin, 0.3-2 parts of chopped fibers and 20-65 parts of water; The particle size of the particles in the graded aggregate is between 2.36 mm and 0.020 mm; in the graded aggregate, the content of particles with a particle size greater than 0.080 mm does not exceed 80%, the content of particles with a particle size greater than 0.170 mm is not less than 58%, and the content of particles with a particle size greater than 0.800 mm does not exceed 38%; The super absorbent resin can absorb 100-400 times its own weight of water; the particle size of the super absorbent resin is 180 μm-420 μm; The early strength agent includes at least one of a nitrate early strength agent, a carbonate early strength agent, an organic early strength agent and a sulfate early strength agent.

2. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 1, characterized in that: The raw materials of the early-strength tile adhesive include, by weight: 30-45 parts of cement, 6-10 parts of mineral admixture, 60-80 parts of graded aggregate, 2-4 parts of glue powder, 0.02-0.06 parts of early-strength agent, 0.01-0.02 parts of thickener, 0.05-0.1 parts of highly absorbent resin, 0.5-1 parts of chopped fibers and 25-55 parts of water; The mineral admixture is a mineral admixture made of clay minerals; in the graded aggregate, the content of particles with a particle size of 0.020mm-0.080mm is 20-28wt%, the content of particles with a particle size of 0.080mm-0.170mm is 10-14wt%, the content of particles with a particle size of 0.170mm-0.800mm is 25-35wt%, and the content of particles with a particle size of 0.800mm-2.36mm is 30-38wt%; the super absorbent resin can absorb 250-350 times its own weight of water; the particle size of the super absorbent resin is 220μm-380μm; the early strength agent includes a nitrate early strength agent, a carbonate early strength agent and an organic early strength agent; the cement is silicate cement and / or ordinary silicate cement.

3. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 2, characterized in that: The highly water-absorbent resin includes at least one of sodium polyacrylate, polyacrylamide, polyvinyl alcohol grafted acrylate, cellulose grafted acrylate and acrylic acid-acrylamide copolymer.

4. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 2, characterized in that: The cement is at least one of P.Ⅱ.52.5, P.Ⅱ.42.5, P.Ⅱ.52.5R, P.Ⅱ.42.5R, PO42.5 and PO52.5; the particle size of the cement does not exceed 80μm; the specific surface area of ​​the cement is 350-450m2 / kg.

5. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 2, characterized in that: The specific surface area of ​​the mineral admixture is 22-28m 2 / g; the mineral admixture includes at least one of kaolin powder, metakaolin powder, bentonite powder, sepiolite powder and illite powder.

6. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 2, characterized in that: The graded aggregate includes at least one of river sand, lake sand, mountain sand, quartz sand, granite sand, basalt sand and regenerated sand.

7. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 2, characterized in that: The rubber powder includes at least one of ethylene-vinyl acetate copolymer rubber powder, acrylic rubber powder, polyvinyl acetate rubber powder, styrene-butadiene rubber powder, polyvinyl alcohol rubber powder, polyurethane rubber powder and starch ether rubber powder.

8. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 2, characterized in that: The early strength agent includes at least one of calcium formate, lithium carbonate, lithium nitrate and calcium nitrate.

9. The early-strength tile adhesive suitable for prefabricated buildings as claimed in claim 2, characterized in that: The thickener is a cellulose thickener; the cellulose thickener includes at least one of hydroxypropyl methylcellulose, methyl cellulose, hydroxymethyl cellulose, and hydroxyethyl cellulose; the viscosity of the cellulose thickener is 90,000-110,000 Pa·s; the chopped fibers are wood fibers; the length of the wood fibers is 4-8 mm; and the diameter of the wood fibers does not exceed 40 μm.

10. A method for preparing an early-strength tile adhesive suitable for prefabricated buildings, characterized in that: The steps include: S1: preparing raw materials according to the number of parts of the raw materials of the early-strength tile adhesive suitable for prefabricated buildings according to any one of claims 1 to 9, and mixing a highly absorbent resin with 10%-20% of water to obtain a highly absorbent resin gel; S2: Mix and stir the early strength agent, thickener and the remaining 80%-90% water to obtain a wet material; S3: Mixing and stirring cement, mineral admixture, graded aggregate, rubber powder and chopped fibers to obtain dry material; S4: Mix and stir the highly absorbent resin gel, dry material and wet material to obtain an early-strength tile adhesive suitable for prefabricated buildings.