Machine-made sand concrete and preparation process thereof

Abstract

The invention relates to the technical field of concrete preparation, and discloses machine-made sand concrete and a preparation process thereof.The machine-made sand concrete comprises broken stone, machine-made sand, cement and water according to a conventional ratio, the cement is slag cement, and the slag cement comprises, by weight, 20-25 parts of steel slag, 18-32 parts of blast furnace slag, 2-4 parts of water, 1-3 parts of a water reducing agent, 1-3 parts of a water reducing agent and 1-3 parts of a water reducing agent. And 6-12 parts of Portland cement clinker. The prepared machine-made sand concrete is good in anti-permeability and anti-carbonization capacity, the chemical corrosion resistance and bonding strength of the machine-made sand concrete are improved through the added barium sulfide industrial waste residues, and the machine-made sand concrete has the long service life. The invention solves the industrial technical problems in preparation of green high-performance concrete from machine-made sand and industrial waste residues, and breaks through the common key technical problems of high-efficiency production regulation and control of machine-made sand and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete preparation, and in particular relates to machine-made sand concrete and a preparation process thereof. Background Art

[0002] In view of the current situation of environmental protection upgrade and the green sustainable development strategy of building materials, the product proposes to use machine-made sand to replace river sand and a large amount of industrial waste slag to prepare green high-performance concrete to meet the needs of large-scale infrastructure construction. Machine-made sand concrete is a kind of concrete extended from the above problems. The existing machine-made sand concrete prepared by steel slag has poor impermeability and carbonization resistance and cannot meet the actual use needs. Therefore, it is necessary to invent a machine-made sand concrete and its preparation process to solve the above problems. Summary of the invention

[0003] In view of the above problems, the present invention provides a machine-made sand concrete and a preparation process thereof to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: A machine-made sand concrete comprises crushed stone, machine-made sand, cement and water in conventional proportions, wherein the cement is slag cement, and the raw materials of the slag cement comprise, by weight, 20-25 parts of steel slag, 18-32 parts of blast furnace slag, 6-12 parts of Portland cement clinker, 1-2 parts of gypsum powder, 13-14 parts of industrial silicon dioxide, 2-4 parts of industrial aluminum oxide, 0.2-0.25 parts of naphthalene sulfonate, 0.01-0.03 parts of polycarboxylic acid, 1-1.5 parts of polypropylene fiber and 6-9 parts of barium sulfide industrial waste residue.

[0005] This product solves the industry technical problems faced in the preparation of green high-performance concrete from machine-made sand and industrial waste slag, and breaks through common key technical problems such as efficient production and regulation of machine-made sand, green preparation of highly adaptable key materials, high-performance design and green preparation of machine-made sand concrete, and regulation and improvement of concrete performance under complex environments. It has achieved innovative results in the entire technology chain of green machine-made sand high-performance concrete material theory, methods, process equipment, products and technologies from green preparation of raw materials, high-performance design to full service life. It has solved the key technologies for high performance and greening of machine-made sand concrete, achieved high-quality production of machine-made sand and efficient recycling of industrial solid waste, broken through the "bottleneck" technology of concrete construction in major engineering projects, and led the sustainable innovation and development of concrete.

[0006] The present invention also provides a process for preparing machine-made sand concrete, which is used to prepare the above machine-made sand concrete. The process comprises the following steps: The above components are mixed uniformly at room temperature through a mixing device to form machine-made sand concrete, wherein the mixing device includes a mixing box, a rotating column is rotatably installed in the middle of the bottom wall of the mixing box, a transmission component for driving the rotating column is provided at the bottom of the mixing box, a circular groove is equidistantly opened around the outer side of the rotating column, a horizontal column is fixedly installed in the circular groove, a stirring blade is fixedly installed at one end of the horizontal column away from the rotating column, a sleeve is provided on the outside of the horizontal column, one end of the sleeve is rotatably installed on the inner wall of the circular groove, a curved cover is provided on the top of the rotating column, and the top of the rotating column A protective frame is fixedly installed on the top, vertical plates corresponding to the sleeve are fixedly installed equidistantly around the bottom of the arc cover, and an annular plate is fixedly installed between multiple vertical plates. An annular groove is opened on the outer side of the rotating column, and the annular plate is slidably arranged in the annular groove. A first spring is fixedly connected to the top of the annular plate, and a driving component for driving its unidirectional rotation is provided on the outside of the sleeve, a lifting component for driving the arc cover to rise is provided on the top of the rotating column, a vibration component for vibrating the sleeve is provided inside, and a discharge component is provided on one side of the mixing box.

[0007] Furthermore, the driving assembly includes a first tooth which is equidistantly arranged around the outside of the sleeve, and the outside of the sleeve is provided with a limiting assembly for limiting it so that it can only rotate in one direction. One end of the vertical plate extends into the circular groove, and a carrier plate is fixedly installed on the outside of the vertical plate at equal distances from top to bottom. The inside of the carrier plate is rotatably provided with a second tooth which cooperates with the first tooth, and a protrusion is provided on the lower part of one side of the second tooth close to the vertical plate, and the top of the protrusion is provided with an arc surface, and the protrusion is in contact with the vertical plate.

[0008] Furthermore, the limiting assembly includes ratchet teeth equidistantly arranged around the outside of the sleeve, and a pawl cooperating with the ratchet teeth is rotatably mounted on the inner wall of the circular groove via a connecting shaft.

[0009] Furthermore, the lifting assembly includes a triangular block fixedly installed in the middle of the bottom end of the arc cover, a motor is fixedly installed on the top of the rotating column, a top plate that cooperates with the triangular block is fixedly installed on the output shaft of the motor, and a battery for powering the motor is provided on the top of the rotating column.

[0010] Furthermore, the vibration assembly includes a racket rod equidistantly arranged inside the sleeve, and the inner walls on both sides of the sleeve are provided with sliding grooves that cooperate with the racket rod. Both ends of the racket rod are slidably arranged in the sliding grooves. The two ends of the racket rod are rectangularly arranged. The side of the racket rod close to the cross column is fixedly connected to the inner wall of the sliding groove through a second spring, and the side of the racket rod close to the cross column is fixedly connected to a wedge plate through a connecting plate, and an L-shaped rod that cooperates with the wedge plate is fixedly installed on the outer side of the cross column.

[0011] Furthermore, the discharge assembly includes a discharge port arranged at the lower outer side of the mixing box, a discharge plate corresponding to the discharge port is fixedly installed on the outer side of the mixing box, and a closing plate corresponding to the discharge port is slidably inserted inside the discharge plate.

[0012] Furthermore, the weights of the crushed stone, machine-made sand, cement and water are 1200kg, 510kg, 460kg and 170kg respectively.

[0013] Technical effects and advantages of the present invention: 1. The machine-made sand concrete prepared by the present invention has good impermeability and carbonation resistance. The added barium sulfide industrial waste slag improves the chemical corrosion resistance and bonding strength of the machine-made sand concrete, so that the machine-made sand concrete has a longer service life. At the same time, by adding silicon dioxide and aluminum oxide, they can be dissolved and hydrolyzed into sol during use. The sol can penetrate into the capillary pores inside the cement paste, block and cut off the capillary pores, increase the density of the cement, and thus increase the water resistance of the cement. In addition to playing the role of a water reducer, the added polycarboxylic acid reacts with the calcium ions in the gypsum to form calcium polycarboxylate, which can be enriched on the surface of the water-made sand concrete, improve the surface strength and density of the machine-made sand concrete, and thus significantly improve the carbonation resistance of the machine-made sand concrete. In addition, the polypropylene fiber greatly improves the impermeability of the machine-made sand concrete. 2. The present invention can clean up the materials dropped on the arc cover and the sleeve during the preparation process, thereby preventing the materials from condensing on the arc cover and the sleeve and causing waste, thereby better carrying out the production and preparation of concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The structure of the mixing device of the embodiment of the present invention is shown in FIG. Figure 1 ; Figure 2 The structure of the mixing device of the embodiment of the present invention is shown in FIG. Figure 2 ; Figure 3 A schematic structural diagram of a rotating column according to an embodiment of the present invention is shown; Figure 4 The cross-sectional structure diagram of the rotating column of the embodiment of the present invention is shown. Figure 1 ; Figure 5 The embodiment of the present invention is shown Figure 4 The enlarged structural diagram at A in the middle; Figure 6 The cross-sectional structure diagram of the rotating column of the embodiment of the present invention is shown. Figure 2 ; Figure 7 The embodiment of the present invention is shown Figure 6 The enlarged structural diagram at B in the middle; Figure 8 The cross-sectional structure diagram of the rotating column of the embodiment of the present invention is shown. Figure 3 ; Fig. 9 The embodiment of the present invention is shown Figure 8 Enlarged structural diagram at point C in the middle.

[0015] In the figure: 1, mixing box; 2, rotating column; 3, transmission assembly; 4, horizontal column; 5, stirring blade; 6, sleeve; 7, arc cover; 8, vertical plate; 9, ring plate; 10, first spring; 11, first tooth; 12, carrier plate; 13, second tooth; 14, bump; 15, ratchet; 16, pawl; 17, triangular block; 18, motor; 19, top plate; 20, clapper rod; 21, second spring; 22, wedge plate; 23, L-shaped rod; 24, discharge plate; 25, closing plate; 26, protective frame. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0017] The invention provides a machine-made sand concrete, comprising crushed stone, machine-made sand, cement and water in conventional proportions, wherein the cement is slag cement, and the raw materials of the slag cement comprise, by weight, 20-25 parts of steel slag, 18-32 parts of blast furnace slag, 6-12 parts of Portland cement clinker, 1-2 parts of gypsum powder, 13-14 parts of industrial silicon dioxide, 2-4 parts of industrial aluminum oxide, 0.2-0.25 parts of naphthalene sulfonate, 0.01-0.03 parts of polycarboxylic acid, 1-1.5 parts of polypropylene fiber and 6-9 parts of barium sulfide industrial waste residue.

[0018] The prepared machine-made sand concrete has good impermeability and carbonation resistance. The added barium sulfide industrial waste slag improves the chemical corrosion resistance and bonding strength of the machine-made sand concrete, so that the machine-made sand concrete has a long service life. At the same time, by adding silicon dioxide and aluminum oxide, they can be dissolved and hydrolyzed into sol during use. The sol can penetrate into the capillary pores inside the cement paste, block and cut off the capillary pores, increase the density of the cement, and thus improve the water resistance of the cement. In addition to playing the role of a water reducer, the added polycarboxylic acid reacts with the calcium ions in the gypsum to form calcium polycarboxylate, so that it can be enriched on the surface of the water-based machine-made sand concrete, improve the surface strength and density of the machine-made sand concrete, and thus significantly improve the carbonation resistance of the machine-made sand concrete. In addition, the polypropylene fiber greatly improves the impermeability of the machine-made sand concrete.

[0019] The present invention also provides a process for preparing machine-made sand concrete, which is used to prepare the machine-made sand concrete. The process comprises the following steps: mixing the above components at room temperature through a mixing device to form machine-made sand concrete; Figures 1 to 9 As shown, the mixing device includes a mixing box 1, a rotating column 2 is rotatably installed in the middle of the bottom wall of the mixing box 1, a transmission component 3 for driving the rotating column 2 is provided at the bottom of the mixing box 1, and the transmission component 3 is a transmission component used for rotating with a main shaft on a flat-mouth concrete mixer in the prior art, and circular grooves are equidistantly arranged around the outer side of the rotating column 2, a horizontal column 4 is fixedly installed in the circular groove, and a stirring blade 5 is fixedly installed at one end of the horizontal column 4 away from the rotating column 2, a sleeve 6 is sleeved on the outer side of the horizontal column 4, and one end of the sleeve 6 is rotatably installed on the inner wall of the circular groove, and a curved cover 7 is provided on the top of the rotating column 2. A protective frame 26 is fixedly installed on the top of the column 2, and vertical plates 8 corresponding to the sleeve 6 are fixedly installed equidistantly around the bottom of the arc cover 7, and a ring plate 9 is fixedly installed between multiple vertical plates 8. An annular groove is opened on the outer side of the rotating column 2, and the ring plate 9 is slidably set in the annular groove. The top of the ring plate 9 is fixedly connected with a first spring 10, and the outside of the sleeve 6 is provided with a driving component for driving its unidirectional rotation. The top of the rotating column 2 is provided with a lifting component for driving the arc cover 7 to rise, and the inside of the sleeve 6 is provided with a vibration component for vibrating it, and a discharge component is provided on one side of the mixing box 1.

[0020] During use, the transmission component 3 drives the rotating column 2, the horizontal column 4, and the stirring blade 5 to rotate, and then the above-mentioned materials are put into the mixing box 1 for mixing. When the materials are put in, due to the use of a forklift to feed the materials, some of the materials will inevitably fall on the arc cover 7 and the sleeve 6. At this time, the arc cover 7 is driven to rise by the lifting component, and the arc cover 7 rises with the vertical plate 8 and the ring plate 9, so that the first spring 10 is compressed to deform it and generate a force. Then the lifting component cancels the lifting of the arc cover 7, and the first spring 10 releases the force to drive the ring plate 9, the vertical plate 8, and the arc cover 7 to fall rapidly. The ring plate 9 collides with the bottom wall of the annular groove to produce The arc cover 7 and the vertical plate 8 are vibrated to shake off the materials on the arc cover 7. During the rising process of the arc cover 7 and the vertical plate 8, the driving component drives the sleeve 6 to rotate unidirectionally, and the vibration component is cooperated to vibrate the sleeve 6. With the rotation and vibration of the sleeve 6, the materials accumulated on the top are separated from its surface. During the whole process, as the mixing proceeds, the arc cover 7 continuously vibrates up and down, and the sleeve 6 also continuously rotates and vibrates unidirectionally, thereby realizing the cleaning of the accumulated materials on the arc cover 7 and the sleeve 6 to avoid the condensation of these materials on the arc cover 7 and the sleeve 6 and causing waste. After the mixing is completed, the mixed concrete is discharged through the discharge component.

[0021] like Figures 4 to 5As shown, the driving assembly includes a first tooth 11 equidistantly arranged around the outside of the sleeve 6, and the outside of the sleeve 6 is provided with a limiting assembly for limiting it so that it can only rotate in one direction. One end of the vertical plate 8 extends into the circular groove, and a carrier plate 12 is fixedly installed on the outside of the vertical plate 8 at equal intervals from top to bottom. The inner side of the carrier plate 12 is rotatably installed with a second tooth 13 that cooperates with the first tooth 11, and a protrusion 14 is provided on the lower part of the side of the second tooth 13 close to the vertical plate 8. The top of the protrusion 14 is provided with an arc surface, and the protrusion 14 is in contact with the vertical plate 8.

[0022] The vertical plate 8 rises, carrying the carrier plate 12, the rotating shaft, the second teeth 13, and the protrusion 14 with it. After the second teeth 13 collide with the first teeth 11, due to the existence of the protrusion 14, the second teeth 13 at this time cannot rotate and remain in a horizontal state. As the second teeth 13 rise, they cooperate with the first teeth 11 to drive the sleeve 6 to rotate forward. When the vertical plate 8 descends, the second teeth 13 collide with the first teeth 11 and rotate upward, so that the second teeth 13 avoid the first teeth 11 to ensure the descent of the vertical plate 8. After the second teeth 13 are separated from the first teeth 11, under the action of gravity, the second teeth 13 are reset to a horizontal state, so that when the vertical plate 8 descends, the sleeve 6 will not rotate. The existence of the limiting component makes the sleeve 6 unable to reverse.

[0023] like Figure 5 As shown, the limiting assembly includes ratchet teeth 15 which are equidistantly arranged around the outside of the sleeve 6, and a ratchet pawl 16 which cooperates with the ratchet teeth 15 is rotatably mounted on the inner wall of the circular groove via a connecting shaft.

[0024] The ratchet 15 and the pawl 16 cooperate to limit the position of the sleeve 6 so that it cannot be reversed but can only rotate forward.

[0025] like Figure 6 As shown, the lifting assembly includes a triangular block 17 fixedly mounted in the middle of the bottom end of the arc cover 7, a motor 18 is fixedly mounted on the top of the rotating column 2, and a top plate 19 that cooperates with the triangular block 17 is fixedly mounted on the output shaft of the motor 18. A battery for powering the motor 18 is provided on the top of the rotating column 2, which is not shown in the figure.

[0026] Start the motor 18 so that its output shaft rotates with the top plate 19, and the top plate 19 contacts the inclined surface of the triangular block 17 to push the triangular block 17 up with the arc cover 7. When the top plate 19 rotates to separate from the triangular block 17, the drive to the arc cover 7 is canceled.

[0027] like Figure 7 and Fig. 9As shown, the vibration assembly includes a racket rod 20 equidistantly arranged in a surrounding manner inside the sleeve 6, and the inner walls on both sides of the sleeve 6 are provided with sliding grooves that cooperate with the racket rod 20. Both ends of the racket rod 20 are slidably arranged in the sliding grooves. The two ends of the racket rod 20 are arranged in a rectangular shape. The side of the racket rod 20 close to the cross column 4 is fixedly connected to the inner wall of the sliding groove through a second spring 21, and the side of the racket rod 20 close to the cross column 4 is fixedly connected to a wedge plate 22 through a connecting plate, and the outer side of the cross column 4 is fixedly installed with an L-shaped rod 23 that cooperates with the wedge plate 22.

[0028] When the sleeve 6 rotates, it moves with the racket bar 20, the connecting plate and the wedge plate 22. When the wedge plate 22 contacts the L-shaped rod 23, the L-shaped rod 23 squeezes the wedge plate 22 along the inclined surface of the wedge plate 22, causing the connecting plate and the racket bar 20 to move toward the direction close to the cross column 4, and at the same time compresses the second spring 21 to deform it and generate a force. When the wedge plate 22 separates from the L-shaped rod 23, the second spring 21 resets and causes the racket bar 20 to quickly reset and hit the inner wall of the sleeve 6 to cause it to vibrate. As the wedge plate 22 continuously contacts and separates from the L-shaped rod 23, the sleeve 6 can be continuously vibrated.

[0029] like Figure 1 As shown, the discharge assembly includes a discharge port arranged at the lower outer side of the mixing box 1, a discharge plate 24 corresponding to the discharge port is fixedly installed on the outer side of the mixing box 1, and a closing plate 25 corresponding to the discharge port is slidably inserted inside the discharge plate 24.

[0030] Pull the closing plate 25 upward to cancel the closing of the discharge port, and the concrete can be discharged.

[0031] The weights of crushed stone, machine-made sand, cement and water are 1200kg, 510kg, 460kg and 170kg respectively.

[0032] Working principle of the mixing equipment: When in use, the transmission component 3 drives the rotating column 2, the horizontal column 4, and the stirring blade 5 to rotate, and then the above materials are put into the mixing box 1 for mixing. When the materials are put in, some of the materials will inevitably fall on the arc cover 7 and the sleeve 6. The motor 18 is started to make its output shaft drive the top plate 19 to rotate. The top plate 19 contacts the inclined surface of the triangular block 17 and drives the triangular block 17 to drive the arc cover 7 up. The arc cover 7 drives the vertical plate 8 and the ring plate 9 to move up, so that the first spring 10 is compressed to deform and generate a force. The vertical plate 8 moves up and drives the carrier plate 12, the rotating shaft, the second tooth 13, and the protrusion 14 to move up. After the second tooth 13 contacts the first tooth 11, due to the presence of the protrusion 14, the second tooth 13 cannot rotate at this time and remains in a horizontal state. As the second tooth 13 rises, it cooperates with the first tooth 11 to drive the sleeve 6 to rotate forward. When the sleeve 6 rotates, it moves with the racket 20, the connecting plate and the wedge plate 22. When the wedge plate 22 contacts the L-shaped rod 23, the L-shaped rod 23 squeezes the wedge plate 22 along the inclined surface of the wedge plate 22, and moves with the connecting plate and the racket 20 in the direction close to the cross column 4, and at the same time compresses the second spring 21 to deform it and generate a force. When the wedge plate 22 separates from the L-shaped rod 23, the second spring 21 is restored. The first spring 10 releases its force to rapidly return the top plate 19 to its original position and slaps the inner wall of the sleeve 6 to make it vibrate. When the top plate 19 rotates to separate from the triangular block 17, the first spring 10 releases its force to rapidly descend the annular plate 9, the vertical plate 8 and the arc cover 7. The annular plate 9 collides with the bottom wall of the annular groove to generate vibration, so that the material on the arc cover 7 is shaken off. The arc cover 7 descends and brings the vertical plate 8 down with it. When the vertical plate 8 descends, the second tooth 13 contacts the first tooth 11 and rotates upward, so that the second tooth 13 avoids the first tooth 11 to ensure the descent of the vertical plate 8. After the second tooth 13 is separated from the first tooth 11, the second tooth 13 is restored under the action of gravity. The position is in a horizontal state, so that when the vertical plate 8 descends, the sleeve 6 will not rotate, and then the subsequent motor 18 continues to operate, so that the arc cover 7 can continuously vibrate and the sleeve 6 can continuously rotate, so that the wedge plate 22 is continuously separated from the L-shaped rod 23, and the sleeve 6 can be continuously vibrated. During the whole process, as the mixing proceeds, the arc cover 7 continuously vibrates up and down, and the sleeve 6 also continuously rotates and vibrates in one direction, thereby realizing the cleaning of the accumulated materials on the arc cover 7 and the sleeve 6, avoiding the condensation of these materials on the arc cover 7 and the sleeve 6 and causing waste. After the mixing is completed, the mixed concrete is discharged through the discharge assembly.

[0033] For example, the present invention also provides a device for preparing machine-made sand concrete, comprising the above-mentioned mixing device.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

Claims

1. A machine-made sand concrete, comprising crushed stone, machine-made sand, cement and water, characterized in that: The cement is slag cement. The raw materials of the slag cement include, by weight: 20-25 parts of steel slag, 18-32 parts of blast furnace slag, 6-12 parts of Portland cement clinker, 1-2 parts of gypsum powder, 13-14 parts of industrial silicon dioxide, 2-4 parts of industrial aluminum oxide, 0.2-0.25 parts of naphthalene sulfonate, 0.01-0.03 parts of polycarboxylic acid, 1-1.5 parts of polypropylene fiber, and 6-9 parts of barium sulfide industrial waste slag.

2. A process for preparing machine-made sand concrete, characterized in that: Used to prepare the machine-made sand concrete as claimed in claim 1, characterized in that it comprises the following steps: The above components are mixed uniformly at room temperature by a mixing device to form machine-made sand concrete, wherein the mixing device comprises a mixing box (1), a rotating column (2) is rotatably mounted in the middle of the bottom wall of the mixing box (1), a transmission assembly (3) for driving the rotating column (2) is provided at the bottom of the mixing box (1), circular grooves are equidistantly arranged around the outer side of the rotating column (2), a transverse column (4) is fixedly mounted in the circular groove, a stirring blade (5) is fixedly mounted at one end of the transverse column (4) away from the rotating column (2), a sleeve (6) is sleeved on the outside of the transverse column (4), one end of the sleeve (6) is rotatably mounted on the inner wall of the circular groove, a curved cover (7) is provided on the top of the rotating column (2), and the rotating column (2) A protective frame (26) is fixedly installed on the top of the arc cover (7), vertical plates (8) corresponding to the sleeve (6) are fixedly installed at equal intervals around the bottom of the arc cover (7), and a ring plate (9) is fixedly installed between the plurality of vertical plates (8). An annular groove is provided on the outer side of the rotating column (2), and the ring plate (9) is slidably arranged in the annular groove. A first spring (10) is fixedly connected to the top of the ring plate (9), a driving component for driving the sleeve (6) to rotate in one direction is provided on the outside of the sleeve (6), a lifting component for driving the arc cover (7) to rise is provided on the top of the rotating column (2), a vibration component for vibrating the sleeve (6) is provided inside the sleeve (6), and a discharge component is provided on one side of the mixing box (1).

3. The process for preparing machine-made sand concrete according to claim 2, characterized in that: The driving assembly comprises a first tooth (11) equidistantly arranged around the outer side of the sleeve (6); a limiting assembly for limiting the sleeve (6) so that it can only rotate in one direction is provided on the outer side of the sleeve (6); one end of the vertical plate (8) extends into the circular groove; a carrier plate (12) is fixedly installed equidistantly from top to bottom on the outer side of the vertical plate (8); a second tooth (13) cooperating with the first tooth (11) is rotatably installed on the inner side of the carrier plate (12) via a rotating shaft; a protrusion (14) is provided on the lower part of a side of the second tooth (13) close to the vertical plate (8); a top of the protrusion (14) is provided with an arc surface, and the protrusion (14) contacts the vertical plate (8).

4. The process for preparing machine-made sand concrete according to claim 3, characterized in that: The limiting assembly comprises ratchet teeth (15) which are equidistantly arranged around the outside of the sleeve (6), and a ratchet pawl (16) which cooperates with the ratchet teeth (15) is rotatably mounted on the inner wall of the circular groove via a connecting shaft.

5. The process for preparing machine-made sand concrete according to claim 4, characterized in that: The lifting assembly comprises a triangular block (17) fixedly mounted in the middle of the bottom end of the arc cover (7); a motor (18) is fixedly mounted on the top of the rotating column (2); a top plate (19) matched with the triangular block (17) is fixedly mounted on the output shaft of the motor (18); and a storage battery for supplying power to the motor (18) is provided on the top of the rotating column (2).

6. The process for preparing machine-made sand concrete according to claim 5, characterized in that: The vibration assembly comprises a racket bar (20) equidistantly arranged in a surrounding manner inside a sleeve (6), the inner walls on both sides of the sleeve (6) are provided with sliding grooves that cooperate with the racket bar (20), both ends of the racket bar (20) are slidably arranged in the sliding grooves, the two ends of the racket bar (20) are arranged in a rectangular shape, the side of the racket bar (20) close to the cross column (4) is fixedly connected to the inner wall of the sliding groove through a second spring (21), the side of the racket bar (20) close to the cross column (4) is fixedly connected to a wedge plate (22) through a connecting plate, and the outer side of the cross column (4) is fixedly installed with an L-shaped rod (23) that cooperates with the wedge plate (22).

7. The process for preparing machine-made sand concrete according to claim 6, characterized in that: The discharge assembly comprises a discharge port arranged at the lower part of the outer side of the mixing box (1); a discharge plate (24) corresponding to the discharge port is fixedly mounted on the outer side of the mixing box (1); a closing plate (25) corresponding to the discharge port is slidably inserted inside the discharge plate (24).

8. The process for preparing machine-made sand concrete according to claim 7, characterized in that: The weights of the crushed stone, machine-made sand, cement and water are 1200kg, 510kg, 460kg and 170kg respectively.

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