Waterborne polyurethane capsule, impact-resistant concrete and preparation method thereof

Abstract

The invention discloses a water-based polyurethane capsule, impact-resistant concrete and a preparation method thereof. The water-based polyurethane capsule comprises the following components in parts by weight: 60-100 parts of a polyvinyl alcohol aqueous solution, 400-500 parts of starch, 5-8 parts of glycerin, 10-20 parts of glucose and 1200-1400 parts of water-based polyurethane. The impact-resistant concrete comprises 42.5% high-heat cement, aggregate, water, a finished water-based polyurethane capsule and an admixture, wherein the mass ratio of the 42.5% high-heat cement, aggregate, water, the finished water-based polyurethane capsule and the admixture is 383.84-400:1818.18:171.72:19.19-20:1. The preparation method of the water-based polyurethane capsule is simple and low in cost. The preparation method of the impact-resistant concrete can evenly disperse the polyurethane and improve the compressive strength and impact-resistant strength of the concrete.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete, and in particular relates to a waterborne polyurethane capsule, a preparation method of the waterborne polyurethane capsule, impact-resistant concrete, and a preparation method of the impact-resistant concrete. Background Art

[0002] Hydraulic channels are specially designed channels in water conservancy projects to guide, control or regulate water flow. According to their functions and water flow directions, hydraulic channels can be divided into many types. As a key material in hydraulic structures, channel concrete needs to have high compressive strength and abrasion resistance to ensure that it can withstand the pressure and impact force generated by the water flow. At the same time, it must also have good frost resistance, durability and corrosion resistance to ensure the safety and efficient operation of water conservancy projects.

[0003] Waterborne polyurethane is a material with excellent properties. By combining it with cement, the performance of cement-based materials can be significantly improved. For example, it can enhance bond strength, reduce brittleness, improve durability, improve mechanical properties and microstructure, and reduce surface permeability. By modifying traditional cement, waterborne polyurethane cement not only improves its mechanical properties and durability, but also reduces brittleness and surface permeability, giving it a wider application prospect in construction projects. Therefore, polyurethane concrete is an effective way to solve the deterioration of concrete and improve durability. However, in the preparation process of existing polyurethane concrete, polyurethane is directly added, but polyurethane is prone to agglomeration and unevenly distributed in the concrete, resulting in unstable quality of polyurethane concrete. Currently, by adding polyurethane capsules into concrete, when the hydration reaction causes the outer wall of the capsule to rupture, the waterborne polyurethane inside is released, which can solve the problem of polyurethane agglomeration.

[0004] Existing methods for preparing polyurethane capsules include interfacial polymerization, in-situ polymerization, solvent volatilization, spray drying, etc. All of the above methods require the preparation of a core material first and then coating the core material with a shell. These methods have the problems of complex processes and high preparation costs. Summary of the Invention

[0005] The first object of the present invention is to provide an aqueous polyurethane capsule to solve the problem of high preparation cost of existing polyurethane capsules.

[0006] The second object of the present invention is to provide a method for preparing the waterborne polyurethane capsule.

[0007] The third object of the present invention is to provide abrasion-resistant concrete to solve the problem of uneven dispersion of polyurethane in existing polyurethane concrete.

[0008] A fourth object of the present invention is to provide a method for preparing impact-resistant concrete.

[0009] The first technical solution adopted by the present invention is that the water-based polyurethane capsule is composed of the following components by weight: 60 to 100 parts of polyvinyl alcohol aqueous solution, 400 to 500 parts of starch, 5 to 8 parts of glycerol, 10 to 20 parts of glucose, and 1200 to 1400 parts of water-based polyurethane.

[0010] The present invention is also characterized in that:

[0011] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles, water and an additive, wherein the mass ratio of polyvinyl alcohol particles: water: additive is 5-15: 85-95: 0.1-1.5;

[0012] The degree of polymerization of the polyvinyl alcohol particles is 500~2400, and the degree of alcoholysis is 87%~89%.

[0013] The second technical solution adopted by the present invention is a method for preparing waterborne polyurethane capsules, which is specifically implemented according to the following steps:

[0014] Step 1: Weigh the following raw materials by weight: 60 to 100 parts of polyvinyl alcohol aqueous solution, 400 to 500 parts of starch, 5 to 8 parts of glycerol, 10 to 20 parts of glucose, and 1200 to 1400 parts of waterborne polyurethane;

[0015] Step 2: Evenly mix the weighed polyvinyl alcohol aqueous solution, starch, glycerol, and glucose, and apply the mixture on a stainless steel conveyor belt. Stop applying the mixture when the thickness reaches a preset thickness to obtain a wet shell material.

[0016] Step 3: remove the wet shell material from the stainless steel conveyor belt and place it into a shell mold and a partition mold to prepare a capsule shell and a sealing partition;

[0017] Step 4, the open ends of the two capsule shells are respectively adhered to the two sides of the closed partition, and after heat treatment, a spherical polyvinyl alcohol capsule shell is obtained;

[0018] Step 5: injecting water-based polyurethane into the outer shell of the spherical polyvinyl alcohol capsule through the injection port, and sealing the injection port after the injection is completed to obtain a finished water-based polyurethane capsule.

[0019] The present invention is also characterized in that:

[0020] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles, water and additives, and the mass ratio of polyvinyl alcohol particles: water: additives is 5-15:85-95:0.1-1.5; the polymerization degree of the polyvinyl alcohol particles is 500-2400, and the alcoholysis degree is 87%-89%.

[0021] The shell mold includes a bottom plate, a magnetic hemispherical base is provided on the bottom plate, a hemispherical cover plate is provided on the outer wall of the magnetic hemispherical base, the hemispherical cover plate is concentrically arranged with the magnetic hemispherical base, a cylindrical cutting knife is inserted at the midpoint of the hemispherical cover plate, a protrusion is provided on the outer wall of the hemispherical cover plate near the bottom plate, and the protrusion is connected to the upper surface of the bottom plate through a double ear seat;

[0022] The partition mold includes a cutting base plate and a movable plate. Load-bearing columns are provided at the four corners of the cutting base plate. Two of the load-bearing columns located on the same side are provided with sliding tracks on the opposite side walls, and the other two load-bearing columns located on the same side are provided with sliding tracks on the opposite side walls. Each sliding track is provided with a slider. The four sliders are respectively provided on the two side walls of the movable plate. A number of cutting tools arranged in a matrix are provided on the lower surface of the movable plate. A through hole A is provided at the end of each load-bearing column and sliding track away from the cutting base plate, and each slider is provided with a through hole B. A pin is inserted in each through hole A and its corresponding through hole B.

[0023] In step 4, the heat treatment temperature is 60° C. to 80° C., and the time is 10 min to 30 min.

[0024] The third technical solution adopted by the present invention is that the impact-resistant concrete is composed of 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule finished product and admixture, and the mass ratio of 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule finished product and admixture is 383.84-400:1818.18:171.72:19.19-20:1;

[0025] The finished waterborne polyurethane capsule is prepared by the above-mentioned preparation method of the waterborne polyurethane capsule.

[0026] The present invention is also characterized in that:

[0027] The aggregate is composed of sand and gravel, with a mass ratio of sand to gravel of 1:1.5;

[0028] The admixture consists of water reducer, air entraining agent and retarder, and the mass ratio of water reducer, air entraining agent and retarder is 19:1:4.75.

[0029] The fourth technical solution adopted by the present invention is a method for preparing abrasion-resistant concrete, which is specifically implemented according to the following steps:

[0030] Step 1, weighing raw materials according to the mass ratio: 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule product and admixture are 383.84~400:1818.18:171.72:19.19~20:1;

[0031] The finished waterborne polyurethane capsule is prepared by the above-mentioned preparation method of the waterborne polyurethane capsule;

[0032] Step 2: Add 42.5 high-heat cement, aggregate, water and admixture into a mixer and stir thoroughly to obtain a mixture. When the mixture temperature reaches 30°C to 35°C, add the finished water-based polyurethane capsule and continue stirring until the capsule shell of the finished water-based polyurethane capsule is completely hydrated and dissolved to obtain impact-resistant concrete.

[0033] The present invention is also characterized in that:

[0034] The mixer includes a mixing drum, a motor is provided on the top of the mixing drum, the output shaft of the motor is connected to one end of a stirring rod, the other end of the stirring rod extends into the interior of the mixing drum, the other end of the stirring rod is connected to the open end of a plurality of U-blades, a temperature sensor is provided at one end of the stirring rod, a partition is provided in the mixing drum and below the stirring rod, a temperature sensor is provided on the lower surface of the partition, a discharge port is provided on the side wall of the mixing drum and close to the partition, and a feed port is provided on the side wall of the mixing drum and away from the partition.

[0035] The beneficial effects of the present invention are:

[0036] (1) The finished waterborne polyurethane capsule prepared by the method of the present invention has good temperature sensitivity. The capsule dissolves due to the heat released by the hydration of 42.5 high-heat cement itself, which promotes the uniform distribution of waterborne polyurethane in concrete, improves the bonding force between aggregate and cement mortar, effectively hinders the development of cracks in all directions in concrete, and significantly improves the compressive strength, crack resistance and durability of concrete.

[0037] (2) The impact-resistant concrete prepared by the method of the present invention has stronger impact resistance than ordinary concrete, and it is clear that waterborne polyurethane can improve the impact-resistant ability of polyurethane concrete;

[0038] (3) The abrasion-resistant concrete prepared by the method of the present invention has a complete wall surface and a dense structure. The waterborne polyurethane can fully wrap the aggregate, the internal voids are filled with a high density, and there are no fine cracks.

[0039] (4) The finished product of the waterborne polyurethane capsule prepared by the method of the present invention has a simple preparation process and low cost, and can achieve a high compressive strength in a relatively short period of time; at the same time, when used to prepare abrasion-resistant concrete, it will continuously increase the connection strength between concretes, thereby improving the overall compressive strength of the abrasion-resistant concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the structure of the shell mold in the preparation method of the water-based polyurethane capsule of the present invention;

[0041] Figure 2 Schematic diagram of the structure of the partition in the preparation method of the waterborne polyurethane capsule of the present invention;

[0042] Figure 3 This is a schematic structural diagram of a finished aqueous polyurethane capsule prepared by the method of the present invention;

[0043] Figure 4 It is a structural schematic diagram of a mixer in the method for preparing impact-resistant concrete of the present invention.

[0044] In the figure, 1. bottom plate, 2. magnetic hemispherical base, 3. hemispherical cover, 4. cylindrical cutting knife, 5. double-ear seat, 6. protrusion, 7. movable plate, 8. load-bearing column, 9. wet shell material, 10. cutting bottom plate, 11. cutting knife, 12. capsule shell, 13. closed partition, 14. injection port, 15. water-based polyurethane, 16. motor, 17. discharge port, 18. temperature sensor, 19. feed port, 20. partition, 21. stirring rod, 22. blade, 23. mixing drum, 24. latch, 25. sliding track. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] The water-based polyurethane capsule of the present invention consists of the following components in parts by weight: 60 to 100 parts of polyvinyl alcohol aqueous solution, 400 to 500 parts of starch, 5 to 8 parts of glycerol, 10 to 20 parts of glucose and 1,200 to 1,400 parts of water-based polyurethane.

[0047] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles, water, and an additive, wherein the mass ratio of polyvinyl alcohol particles: water: additive is 5-15: 85-95: 0.1-1.5; the additive is glycerol;

[0048] The degree of polymerization of the polyvinyl alcohol particles is 500~2400, and the degree of alcoholysis is 87%~89%.

[0049] The preparation method of the waterborne polyurethane capsule of the present invention is specifically implemented according to the following steps:

[0050] Step 1: Weigh the following raw materials by weight: 60 to 100 parts of polyvinyl alcohol aqueous solution, 400 to 500 parts of starch, 5 to 8 parts of glycerol, 10 to 20 parts of glucose, and 1200 to 1400 parts of waterborne polyurethane;

[0051] Step 2: Evenly mix the weighed polyvinyl alcohol aqueous solution, starch, glycerol, and glucose, and apply the mixture on a stainless steel conveyor belt. Stop applying the mixture when the thickness reaches a preset thickness to obtain a wet shell material.

[0052] Step 3: remove the wet shell material from the stainless steel conveyor belt and place it into a shell mold and a partition mold to prepare a hemispherical capsule shell and a closed partition;

[0053] like Figure 1 As shown, the shell mold includes a base plate 1, on which a magnetic hemispherical base 2 is provided. The base plate 1 is made of metal. The magnetic hemispherical base 2 can be adsorbed on the base plate 1, which is convenient for disassembly, replacement and position adjustment. A hemispherical cover plate 3 is provided on the outer wall of the magnetic hemispherical base 2. The hemispherical cover plate 3 is concentrically arranged with the magnetic hemispherical base 2. A cylindrical cutting knife 4 is inserted at the midpoint of the hemispherical cover plate 3. The blade of the cylindrical cutting knife 4 extends into the interior of the hemispherical cover plate 3 and the extension length is the same as the thickness of the wet shell material, and is used to cut the injection port on the wet shell material. A protrusion 6 is provided on the outer wall of the hemispherical cover plate 3 and close to the base plate 1. The protrusion 6 is connected to the upper surface of the base plate 1 through a double-ear seat 5;

[0054] The diameter of the magnetic hemispherical base 2 is 20 mm;

[0055] like Figure 2 As shown, the partition mold includes a cutting base plate 10 and a movable plate 7. The four corners of the cutting base plate 10 are provided with load-bearing columns 8, and two of the load-bearing columns 8 on the same side are provided with sliding tracks 25 on the opposite side walls. The other two load-bearing columns 8 on the same side are provided with sliding tracks 25 on the opposite side walls. Each sliding track 25 is provided with a slider. The four sliders are respectively provided on the two side walls of the movable plate 7. Through the cooperation of the sliders and the sliding tracks 25, the movable plate 7 can slide up and down relative to the load-bearing columns 8. The lower surface of the movable plate 7 is provided with a plurality of rectangular The cutting tools 11 are arranged in an array. The cutting tools 11 are cylindrical with an inner diameter of 25 mm. The closed partition after cutting is circular. Each load-bearing column 8 and the sliding rail 25 are provided with a through hole A at the end away from the cutting base plate 10. Each slider is provided with a through hole B. Each through hole A and its corresponding through hole B are inserted with a pin 24. After cutting, the movable plate 7 is moved up so that the through hole A is aligned with the through hole B, and then the pin 24 is inserted into the through hole A and the through hole B, thereby fixing the position of the movable plate 7. When in use, the pin 24 is removed and the movable plate 7 can be moved down for cutting.

[0056] The specific process is as follows: open the hemispherical cover plate 3, remove the wet shell material from the stainless steel transmission belt and place it on the magnetic hemispherical base 2 and ensure that the wet shell material completely covers the magnetic hemispherical base 2, close the hemispherical cover plate 3 and press the hemispherical cover plate 3, the wet shell material is cut by the cylindrical cutting knife 4 to form an injection port, and then peeled off after drying to form a hemispherical capsule shell. The wall thickness of the hemispherical capsule shell is 5mm;

[0057] The wet shell material is removed from the stainless steel conveyor belt and placed on the cutting base 10. The latch 24 is removed, and the movable plate 7 is moved downward along the sliding track 25. The wet shell material is cut with the cutting tool 11. After cutting, the movable plate 7 is moved up along the sliding track 25 so that the through hole A is aligned with the through hole B. The latch 24 is then inserted into the through hole A and the through hole B to fix the movable plate 7. After the cut wet shell material is dried, it is removed to obtain a closed partition.

[0058] Step 4: Take two hemispherical capsule shells and a closed partition, adhere the open ends of the two capsule shells to both sides of the closed partition with acrylic adhesive, and obtain spherical polyvinyl alcohol capsule shells after heat treatment;

[0059] The heat treatment temperature is 60°C to 80°C, and the time is 10min to 30min;

[0060] Step 5: inject water-based polyurethane into the shell of the spherical polyvinyl alcohol capsule through the injection port. After the injection is completed, apply hot melt adhesive or inject PVA solution to the injection port to seal it. After curing, the result is as shown in FIG. Figure 3 The finished water-based polyurethane capsule shown is spherical and has the following structure: it includes a closed partition 13, with hemispherical capsule shells 12 bonded to both sides of the closed partition 13, an injection port 14 is provided at the center of each hemispherical capsule shell 12, and each hemispherical capsule shell 12 is filled with water-based polyurethane 15.

[0061] The shell of the spherical polyvinyl alcohol capsule of the present invention is produced by an esterification cross-linking reaction between starch and polyvinyl alcohol, thereby reducing the hydroxyl groups between molecules, weakening the hydrogen bonding effect, and lowering the crystallinity. At the same time, a glycerol small molecule plasticizer is added to lower the melting point.

[0062] The impact-resistant concrete of the present invention is composed of 42.5°C high-heat cement, aggregate, water, a finished water-based polyurethane capsule product and an admixture, wherein the mass ratio of the 42.5°C high-heat cement, aggregate, water, the finished water-based polyurethane capsule product and the admixture is 383.84-400:1818.18:171.72:19.19-20:1;

[0063] The finished waterborne polyurethane capsule is prepared by the above-mentioned preparation method of the waterborne polyurethane capsule;

[0064] Among them, the aggregate is composed of sand and crushed stone, and the mass ratio of sand to crushed stone is 1:1.5;

[0065] The admixture consists of water reducer, air entraining agent and retarder, and the mass ratio of water reducer, air entraining agent and retarder is 19:1:4.75.

[0066] The method for preparing the impact-resistant concrete of the present invention is specifically implemented according to the following steps:

[0067] Step 1, weighing raw materials according to the mass ratio: 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule product and admixture are 383.84~400:1818.18:171.72:19.19~20:1;

[0068] The finished waterborne polyurethane capsule is prepared by the above-mentioned preparation method of the waterborne polyurethane capsule;

[0069] Step 2: Add 42.5 high-heat cement, aggregate, water, and admixtures into a mixer and stir thoroughly to obtain a mixture. When the mixture temperature reaches 30° C. to 35° C., add the finished waterborne polyurethane capsule and continue stirring until the capsule shell of the finished waterborne polyurethane capsule is completely hydrated and dissolved, thereby obtaining impact-resistant concrete.

[0070] The stirring process after adding the finished waterborne polyurethane capsule is as follows: first stir at a low speed for 1 minute, then adjust the frequency of the motor 16 and stir at a high speed for 2 minutes;

[0071] Among them, such as Figure 4 As shown, the mixer includes a mixing drum 23, a motor 16 is provided on the top of the mixing drum 23, an output shaft of the motor 16 is connected to one end of a stirring rod 21, the other end of the stirring rod 21 extends into the mixing drum 23, and the other end of the stirring rod 21 is connected to the open ends of multiple U-shaped blades 22, a partition 20 is provided in the mixing drum 23 and below the stirring rod 21, a temperature sensor 18 is provided on the lower surface of the partition 20, a discharge port 17 is provided on the side wall of the mixing drum 23 and near the partition 20, a feed port 19 is provided on the side wall of the mixing drum 23 and away from the partition 20, and a valve is provided on the discharge port 17;

[0072] The specific process of adding the cement, aggregate, water and admixture into the mixer is as follows: adding the heated cement, aggregate, water and admixture into the mixing drum 23, starting the motor 16, and the stirring rod 21 drives the blade 22 to rotate for stirring.

[0073] The use of the U-shaped blade 22 can support low-speed or progressive stirring and can reduce shear force during the stirring process.

[0074] After pouring, the abrasion-resistant concrete of the present invention needs to be vibrated immediately to prevent the concrete from setting initially.

[0075] The vibration process is:

[0076] The anti-abrasion concrete is poured in layers, and the thickness of each layer is 15cm~20cm. After each layer is poured, it needs to be vibrated with an inserted vibrator. The vibrator is vertically inserted into each layer of anti-abrasion concrete until it reaches the anti-abrasion concrete of the lower layer. At the same time, when inserting the vibrator, it is necessary to move from the edge to the center. When vibrating, the spacing between the insertion points of the vibrator is controlled at 30cm~50cm, and the vibration time for each point is 10s~20s, based on the surface being slurry and no bubbles emerging, to avoid over-vibration or missed vibration. The vibration frequency is 30Hz~50Hz.

[0077] When vibrating, avoid staying in the same position for a long time. You can move the vibrator slightly after each insertion to ensure uniform vibration and sufficient removal of bubbles and gaps. Slowly pull out the vibrator during vibration to avoid creating voids.

[0078] The curing process of the abrasion-resistant concrete of the present invention is as follows:

[0079] After the initial setting of the impact-resistant concrete (2h~4h after pouring), it is cured using steam curing at a curing temperature of 40℃~60℃ to avoid decomposition of polyurethane or performance degradation caused by high temperature. The heating rate should not exceed 10℃ / h to avoid cracking caused by sudden temperature changes. The relative humidity should be maintained at 90%~100% to ensure sufficient hydration of the cement. The curing time is 12h~24h. After the curing is completed, the cooling rate should not exceed 10℃ / h to avoid excessive temperature differences.

[0080] Example 1

[0081] The preparation method of the waterborne polyurethane capsule of the present invention is specifically implemented according to the following steps:

[0082] Step 1: weigh the following raw materials by weight: 60 parts of polyvinyl alcohol aqueous solution, 400 parts of starch, 5 parts of glycerol, 10 parts of glucose, and 1200 parts of water-based polyurethane;

[0083] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles with a degree of polymerization of 500-2400 and a degree of alcoholysis of 88%, water, and glycerol. The mass ratio of polyvinyl alcohol particles: water: glycerol is 5:85:0.1.

[0084] Step 2: Evenly mix the weighed polyvinyl alcohol aqueous solution, starch, glycerol, and glucose, and apply the mixture on a stainless steel conveyor belt until the thickness reaches 5 mm, thereby obtaining a wet shell material.

[0085] Step 3: open the hemispherical cover plate 3, remove the wet shell material from the stainless steel transmission belt and place it on the magnetic hemispherical base 2, ensuring that the wet shell material completely covers the magnetic hemispherical base 2. After closing the hemispherical cover plate 3, press the hemispherical cover plate 3, and the wet shell material is cut into an injection port by the cylindrical cutting knife 4. After drying, peel it off to form a hemispherical capsule shell.

[0086] Remove the wet shell material from the stainless steel conveyor belt and place it on the cutting base 10. Remove the hook from the U-shaped connector, press the movable plate 7 down along the load-bearing column 8, and use the cutting tool 11 to cut the wet shell material. After cutting, move the movable plate 7 up along the load-bearing column 8 and hang the hook on the U-shaped connector. After the cut wet shell material is dried, take it out to obtain a closed partition with a diameter of 25 mm.

[0087] Step 4: Take two hemispherical capsule shells and a closed partition, adhere the open ends of the two capsule shells to both sides of the closed partition with acrylic adhesive, and obtain spherical polyvinyl alcohol capsule shells after heat treatment;

[0088] The heat treatment temperature is 60°C and the time is 30 min.

[0089] Step 5: inject water-based polyurethane into the shell of the spherical polyvinyl alcohol capsule through the injection port. The filling amount of water-based polyurethane is 95% of the volume of the polyvinyl alcohol capsule shell. After the injection, apply hot melt adhesive or inject PVA solution to the injection port for sealing. After curing for 30 minutes, the finished water-based polyurethane capsule is obtained.

[0090] The method for preparing the impact-resistant concrete of the present invention is specifically implemented according to the following steps:

[0091] Step 1, weighing raw materials according to the mass ratio: cement, aggregate, water, water-based polyurethane capsule finished product and admixture is 383.84:1818.18:171.72:19.19:1;

[0092] Step 2: Add 42.5 high-heat cement, aggregate, water, and admixtures into a mixer and stir thoroughly to obtain a mixture. When the mixture temperature reaches 30° C., add the finished waterborne polyurethane capsule and continue stirring until the capsule shell of the finished waterborne polyurethane capsule is completely hydrated and dissolved, thereby obtaining abrasion-resistant concrete.

[0093] The stirring process after adding the finished waterborne polyurethane capsule is as follows: first stirring at a low speed for 1 minute, then adjusting the frequency of the motor 16 and stirring at a high speed for 2 minutes.

[0094] Example 2

[0095] The preparation method of the waterborne polyurethane capsule of the present invention differs from that of Example 1 in that:

[0096] The following raw materials were weighed in parts by weight: 80 parts of polyvinyl alcohol aqueous solution, 450 parts of starch, 6.5 parts of glycerol, 15 parts of glucose, and 1300 parts of water-based polyurethane.

[0097] The preparation method of the abrasion-resistant concrete of the present invention is the same as that of Example 1.

[0098] Example 3

[0099] The preparation method of the waterborne polyurethane capsule of the present invention differs from that of Example 1 in that:

[0100] The following raw materials were weighed in parts by weight: 100 parts of polyvinyl alcohol aqueous solution, 500 parts of starch, 8 parts of glycerol, 20 parts of glucose, and 1400 parts of water-based polyurethane;

[0101] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles with a degree of polymerization of 500-2400 and a degree of alcoholysis of 89%, water, and glycerol. The mass ratio of polyvinyl alcohol particles: water: glycerol is 5:85:0.1.

[0102] The preparation method of the abrasion-resistant concrete of the present invention is the same as that of Example 1.

[0103] Example 4

[0104] The preparation method of the waterborne polyurethane capsule of the present invention is specifically implemented according to the following steps:

[0105] Step 1: weigh the following raw materials by weight: 80 parts of polyvinyl alcohol aqueous solution, 400 parts of starch, 6 parts of glycerol, 15 parts of glucose, and 1300 parts of water-based polyurethane;

[0106] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles with a degree of polymerization of 500-2400 and a degree of alcoholysis of 87%, water, and glycerol. The mass ratio of polyvinyl alcohol particles: water: glycerol is 15:95:1.5.

[0107] Step 2: Evenly mix the weighed polyvinyl alcohol aqueous solution, starch, glycerol, and glucose, and apply the mixture on a stainless steel conveyor belt until the thickness reaches 5 mm, thereby obtaining a wet shell material.

[0108] Step 3: open the hemispherical cover plate 3, remove the wet shell material from the stainless steel transmission belt and place it on the magnetic hemispherical base 2, ensuring that the wet shell material completely covers the magnetic hemispherical base 2. After closing the hemispherical cover plate 3, press the hemispherical cover plate 3, and the wet shell material is cut into an injection port by the cylindrical cutting knife 4. After drying, peel it off to form a hemispherical capsule shell.

[0109] Remove the wet shell material from the stainless steel conveyor belt and place it on the cutting base 10. Remove the hook from the U-shaped connector, press the movable plate 7 down along the load-bearing column 8, and use the cutting tool 11 to cut the wet shell material. After cutting, move the movable plate 7 up along the load-bearing column 8 and hang the hook on the U-shaped connector. After the cut wet shell material is dried, take it out to obtain a closed partition with a diameter of 25 mm.

[0110] Step 4: Take two hemispherical capsule shells and a closed partition, adhere the open ends of the two capsule shells to both sides of the closed partition with acrylic adhesive, and obtain spherical polyvinyl alcohol capsule shells after heat treatment;

[0111] The heat treatment temperature is 70°C and the time is 20 min.

[0112] Step 5: inject water-based polyurethane into the shell of the spherical polyvinyl alcohol capsule through the injection port. The filling amount of water-based polyurethane is 100% of the volume of the polyvinyl alcohol capsule shell. After the injection, apply hot melt adhesive or inject PVA solution to the injection port for sealing. After curing for 30 minutes, the finished water-based polyurethane capsule is obtained.

[0113] The method for preparing the impact-resistant concrete of the present invention is specifically implemented according to the following steps:

[0114] Step 1, weighing raw materials according to the mass ratio: 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule finished product and admixture are 383.84:1818.18:171.72:19.46:1;

[0115] Step 2: Add 42.5 high-heat cement, aggregate, water, and admixtures into a mixer and stir thoroughly to obtain a mixture. When the mixture temperature reaches 35° C., add the finished waterborne polyurethane capsule and continue stirring until the capsule shell of the finished waterborne polyurethane capsule is completely hydrated and dissolved, thereby obtaining abrasion-resistant concrete.

[0116] The stirring process after adding the finished waterborne polyurethane capsule is as follows: first stirring at a low speed for 1 minute, then adjusting the frequency of the motor 16 and stirring at a high speed for 2 minutes.

[0117] Example 5

[0118] The preparation method of the waterborne polyurethane capsule of the present invention is specifically implemented according to the following steps:

[0119] Step 1: weigh the following raw materials by weight: 100 parts of polyvinyl alcohol aqueous solution, 450 parts of starch, 5 parts of glycerol, 20 parts of glucose, and 1400 parts of water-based polyurethane;

[0120] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles with a degree of polymerization of 500-2400 and a degree of alcoholysis of 88%, water, and glycerol. The mass ratio of polyvinyl alcohol particles: water: glycerol is 10:90:1.

[0121] Step 2: Evenly mix the weighed polyvinyl alcohol aqueous solution, starch, glycerol, and glucose, and apply the mixture on a stainless steel conveyor belt until the thickness reaches 5 mm, thereby obtaining a wet shell material.

[0122] Step 3: open the hemispherical cover plate 3, remove the wet shell material from the stainless steel transmission belt and place it on the magnetic hemispherical base 2, ensuring that the wet shell material completely covers the magnetic hemispherical base 2. After closing the hemispherical cover plate 3, press the hemispherical cover plate 3, and the wet shell material is cut into an injection port by the cylindrical cutting knife 4. After drying, peel it off to form a hemispherical capsule shell.

[0123] Remove the wet shell material from the stainless steel conveyor belt and place it on the cutting base 10. Remove the hook from the U-shaped connector, press the movable plate 7 down along the load-bearing column 8, and use the cutting tool 11 to cut the wet shell material. After cutting, move the movable plate 7 up along the load-bearing column 8 and hang the hook on the U-shaped connector. After the cut wet shell material is dried, take it out to obtain a closed partition with a diameter of 25 mm.

[0124] Step 4: Take two hemispherical capsule shells and a closed partition, adhere the open ends of the two capsule shells to both sides of the closed partition with acrylic adhesive, and obtain spherical polyvinyl alcohol capsule shells after heat treatment;

[0125] The heat treatment temperature is 80°C and the time is 10 min.

[0126] Step 5: inject water-based polyurethane into the shell of the spherical polyvinyl alcohol capsule through the injection port. The filling amount of water-based polyurethane is 100% of the volume of the polyvinyl alcohol capsule shell. After the injection, apply hot melt adhesive or inject PVA solution to the injection port for sealing. After curing for 30 minutes, the finished water-based polyurethane capsule is obtained.

[0127] The method for preparing the impact-resistant concrete of the present invention is specifically implemented according to the following steps:

[0128] Step 1, weighing raw materials according to the mass ratio: 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule finished product and admixture are 383.84:1818.18:171.72:19.73:1;

[0129] Step 2: Add 42.5 high-heat cement, aggregate, water, and admixtures into a mixer and stir thoroughly to obtain a mixture. When the mixture temperature reaches 35° C., add the finished waterborne polyurethane capsule and continue stirring until the capsule shell of the finished waterborne polyurethane capsule is completely hydrated and dissolved, thereby obtaining abrasion-resistant concrete.

[0130] The stirring process after adding the finished waterborne polyurethane capsule is as follows: first stirring at a low speed for 1 minute, then adjusting the frequency of the motor 16 and stirring at a high speed for 2 minutes.

[0131] Example 6

[0132] The preparation method of the waterborne polyurethane capsule of the present invention is specifically implemented according to the following steps:

[0133] Step 1: weigh the following raw materials by weight: 100 parts of polyvinyl alcohol aqueous solution, 500 parts of starch, 8 parts of glycerol, 20 parts of glucose, and 1400 parts of water-based polyurethane;

[0134] The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles with a degree of polymerization of 500-2400 and a degree of alcoholysis of 89%, water, and glycerol, with the mass ratio of polyvinyl alcohol particles: water: glycerol being 15:95:1.5;

[0135] Step 2: Evenly mix the weighed polyvinyl alcohol aqueous solution, starch, glycerol, and glucose, and apply the mixture on a stainless steel conveyor belt until the thickness reaches 5 mm, thereby obtaining a wet shell material.

[0136] Step 3: open the hemispherical cover plate 3, remove the wet shell material from the stainless steel transmission belt and place it on the magnetic hemispherical base 2, ensuring that the wet shell material completely covers the magnetic hemispherical base 2. After closing the hemispherical cover plate 3, press the hemispherical cover plate 3, and the wet shell material is cut into an injection port by the cylindrical cutting knife 4. After drying, peel it off to form a hemispherical capsule shell.

[0137] Remove the wet shell material from the stainless steel conveyor belt and place it on the cutting base 10. Remove the hook from the U-shaped connector, press the movable plate 7 down along the load-bearing column 8, and use the cutting tool 11 to cut the wet shell material. After cutting, move the movable plate 7 up along the load-bearing column 8 and hang the hook on the U-shaped connector. After the cut wet shell material is dried, take it out to obtain a closed partition with a diameter of 25 mm.

[0138] Step 4: Take two hemispherical capsule shells and a closed partition, adhere the open ends of the two capsule shells to both sides of the closed partition with acrylic adhesive, and obtain spherical polyvinyl alcohol capsule shells after heat treatment;

[0139] The heat treatment temperature is 60°C and the time is 20 min.

[0140] Step 5: inject water-based polyurethane into the shell of the spherical polyvinyl alcohol capsule through the injection port. The filling amount of water-based polyurethane is 100% of the volume of the polyvinyl alcohol capsule shell. After the injection, apply hot melt adhesive or inject PVA solution to the injection port for sealing. After curing for 30 minutes, the finished water-based polyurethane capsule is obtained.

[0141] The method for preparing the impact-resistant concrete of the present invention is specifically implemented according to the following steps:

[0142] Step 1, weighing the raw materials according to the mass ratio: 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule finished product and admixture are 400:1818.18:171.72:20:1;

[0143] Step 2: Add 42.5 high-heat cement, aggregate, water, and admixtures into a mixer and stir thoroughly to obtain a mixture. When the mixture temperature reaches 30° C., add the finished waterborne polyurethane capsule and continue stirring until the capsule shell of the finished waterborne polyurethane capsule is completely hydrated and dissolved, thereby obtaining abrasion-resistant concrete.

[0144] The stirring process after adding the finished waterborne polyurethane capsule is as follows: first stirring at a low speed for 1 minute, then adjusting the frequency of the motor 16 and stirring at a high speed for 2 minutes.

[0145] Comparative Example

[0146] The difference between the preparation method of concrete and Example 1 is that no water-based polyurethane capsule product is added, and the rest is exactly the same as Example 1.

[0147] The abrasion-resistant concrete obtained in Example 1, Example 2, and Example 3 and the concrete obtained in the comparative example were made into test specimens, respectively. The preparation time conditions and methods were exactly the same. The test specimens were used to measure the compressive strength and abrasion resistance. The specific test data are shown in Table 1.

[0148] Table 1

[0149]

[0150] It can be seen from Table 1 that the compressive strength and the anti-abrasion strength of the impact-resistant concrete prepared by the method of the present invention far exceed those of the comparative example. Therefore, the compressive strength and the anti-abrasion strength of the impact-resistant concrete prepared by the method of the present invention are both high.

Claims

1. A method for preparing waterborne polyurethane capsules, characterized in that: Please follow the steps below to implement: Step 1: Weigh the following raw materials by weight: 60 to 100 parts of polyvinyl alcohol aqueous solution, 400 to 500 parts of starch, 5 to 8 parts of glycerol, 10 to 20 parts of glucose, and 1200 to 1400 parts of waterborne polyurethane; Step 2: Evenly mix the weighed polyvinyl alcohol aqueous solution, starch, glycerol, and glucose, and apply the mixture on a stainless steel conveyor belt. Stop applying the mixture when the thickness reaches a preset thickness to obtain a wet shell material. Step 3: remove the wet shell material from the stainless steel conveyor belt and place it into a shell mold and a partition mold to prepare a capsule shell and a sealing partition; The shell mold comprises a bottom plate (1), a magnetic hemispherical base (2) is provided on the bottom plate (1), a hemispherical cover plate (3) is provided on the outer wall of the magnetic hemispherical base (2), the hemispherical cover plate (3) is concentrically arranged with the magnetic hemispherical base (2), a cylindrical cutting knife (4) is inserted at the midpoint of the hemispherical cover plate (3), a protrusion (6) is provided on the outer wall of the hemispherical cover plate (3) and close to the bottom plate (1), and the protrusion (6) is connected to the upper surface of the bottom plate (1) through a double-ear seat (5); The partition mold includes a cutting base plate (10) and a movable plate (7), and the four corners of the cutting base plate (10) are provided with load-bearing columns (8), wherein two load-bearing columns (8) located on the same side are provided with sliding rails (25) on the opposite side walls, and the other two load-bearing columns (8) located on the same side are provided with sliding rails (25) on the opposite side walls, and each of the sliding rails (25) is provided with a slider, and the four sliders are respectively provided on the two side walls of the movable plate (7), and a plurality of cutting tools (11) arranged in a matrix are provided on the lower surface of the movable plate (7), and each of the load-bearing columns (8) and the sliding rail (25) is provided with a through hole A at one end away from the cutting base plate (10), and each of the sliders is provided with a through hole B, and each through hole A and its corresponding through hole B are provided with a latch (24); Step 4, the open ends of the two capsule shells are respectively adhered to the two sides of the closed partition, and after heat treatment, a spherical polyvinyl alcohol capsule shell is obtained; Step 5: injecting water-based polyurethane into the outer shell of the spherical polyvinyl alcohol capsule through the injection port, and sealing the injection port after the injection is completed to obtain a finished water-based polyurethane capsule.

2. The method for preparing the waterborne polyurethane capsule according to claim 1, wherein: The polyvinyl alcohol aqueous solution is prepared by mixing polyvinyl alcohol particles, water, and additives, wherein the mass ratio of polyvinyl alcohol particles: water: additives is 5-15: 85-95: 0.1-1.5; the degree of polymerization of the polyvinyl alcohol particles is 500-2400, and the degree of alcoholysis is 87%-89%.

3. The method for preparing the waterborne polyurethane capsule according to claim 1, wherein: In step 4, the heat treatment temperature is 60° C. to 80° C., and the time is 10 min to 30 min.

4. Abrasion-resistant concrete, characterized in that: The method comprises 42.5 high-heat cement, aggregate, water, a finished water-based polyurethane capsule product and an admixture, wherein the mass ratio of the 42.5 high-heat cement, aggregate, water, the finished water-based polyurethane capsule product and the admixture is 383.84-400:1818.18:171.72:19.19-20:1; The finished waterborne polyurethane capsule is prepared by the preparation method according to any one of claims 1 to 3.

5. The abrasion-resistant concrete according to claim 4, characterized in that: The aggregate is composed of sand and gravel, and the mass ratio of the sand to the gravel is 1:1.5; The admixture consists of a water reducer, an air entraining agent, and a retarder, and the mass ratio of the water reducer, the air entraining agent, and the retarder is 19:1:4.

75.

6. A method for preparing abrasion-resistant concrete, characterized in that: Please follow the steps below to implement: Step 1, weighing raw materials according to the mass ratio: 42.5 high-heat cement, aggregate, water, water-based polyurethane capsule product and admixture are 383.84~400:1818.18:171.72:19.19~20:1; The finished waterborne polyurethane capsule is prepared by the preparation method according to any one of claims 1 to 3; Step 2: Add 42.5 high-heat cement, aggregate, water and admixtures respectively during stirring, stir thoroughly to obtain a mixture, add the finished water-based polyurethane capsule when the mixture temperature reaches 30°C to 35°C, and continue stirring until the capsule shell of the finished water-based polyurethane capsule is completely hydrated and dissolved to obtain impact-resistant concrete.

7. The method for preparing abrasion-resistant concrete according to claim 6, wherein: The mixer comprises a mixing drum (23), wherein a motor (16) is provided on the top of the mixing drum (23), an output shaft of the motor (16) is connected to one end of a mixing rod (21), the other end of the mixing rod (21) extends into the mixing drum (23), the other end of the mixing rod (21) is connected to the open ends of a plurality of U-shaped blades (22), a partition (20) is provided in the mixing drum (23) and below the mixing rod (21), a temperature sensor (18) is provided on the lower surface of the partition (20), a discharge port (17) is provided on the side wall of the mixing drum (23) and close to the partition (20), and a feed port (19) is provided on the side wall of the mixing drum (23) and away from the partition (20).

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