A device and method for preparing high-strength composite lightweight building blocks for load-bearing structures

Abstract

The present invention discloses a preparation device and method for high-strength composite lightweight building blocks for load-bearing structures, comprising a bottom cladding material distribution device, a horizontal rectangular vertical extrusion device, a horizontally movable embryo core feeding device, a side gap primary cladding material distribution device, a horizontal rectangular annular vertical compaction mold, a side gap secondary cladding material distribution device, a horizontal rectangular annular vertical secondary compaction mold, etc.; the method comprises foaming molding of core material raw materials, dehydration and initial curing of the whole embryo, embryo core cutting and molding, metering and premixing of cladding material, atomization and water addition of cladding powder material, etc.; the present invention arranges the core material cladding process into three steps, the first step is vibrating and cladding the bottom surface of the mold, the second step is vibrating and filling and compacting the side gap, and the third step is filling the cladding material again while vibrating. The step-by-step cladding process can make the cladding around the core material uniform and dense, avoid the defect of different density of the peripheral cladding material products caused by one or two pressure molding, and realize industrial production.

Description

Technical Field

[0001] The present invention relates to a building block and a preparation method thereof, and in particular to a device and method for preparing a high-strength composite building block which is made of powder concrete as a cladding material and foamed concrete as a core material and can be used for load-bearing structures. Background Art

[0002] Currently, domestically produced lightweight foam concrete blocks, regardless of whether they are autoclaved or not, cannot be directly used in load-bearing structures. Due to their surface material, they also have drawbacks such as difficulty bonding to the finishing layer and are prone to cracking and hollowing. Existing composite lightweight concrete blocks also suffer from excessive dry bulk density, low thermal insulation, poor bonding, and weak adhesion to the decorative layer, hindering their widespread adoption. Market research indicates that the domestic market currently lacks high-strength lightweight blocks with a compressive strength of 12.5 MPa suitable for direct use in load-bearing structures. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides a technical solution as follows: a device for preparing high-strength composite lightweight building blocks for load-bearing structures, comprising a cladding forming area, a demoulding, cleaning and box-closing area, and a conveyor belt running through the cladding forming area and the demoulding, cleaning and box-closing area, wherein the conveyor belt is provided with same-diameter redirecting rollers at both ends, and a plurality of detachable forming molds are provided at intervals on the upper part of the conveyor belt; in the cladding forming area, a bottom cladding material distributing device, a horizontal rectangular vertical extrusion device, a horizontally movable embryo core feeding device, a side gap primary cladding material distributing device, a horizontal rectangular annular vertical compacting mold, a side gap secondary cladding material distributing device, a horizontal rectangular annular vertical secondary compacting mold, a side gap top cladding material distributing device, and a horizontal rectangular annular vertical tertiary compacting mold are provided at intervals along the conveying direction of the conveyor belt and above the mold; in the demoulding, cleaning and box-closing area, a cladding block lateral ejecting device, an empty mold lateral cleaning device, and a release agent coating nozzle device are provided at intervals along the conveying direction of the conveyor belt and above the mold;

[0004] The present invention also discloses a method for preparing a high-strength composite lightweight building block for a load-bearing structure, comprising the following steps:

[0005] S1. Foaming of core material

[0006] The core material raw materials are pre-mixed uniformly in a mixer; high-concentration naphthalene water-reducing agent, composite air-entraining agent and mixing water are uniformly mixed, and then mixed with the former to form a slurry for standby use; the composite air-entraining agent and foaming agent are diluted with 40-45 times water, and foamed using a foaming machine to form a foam slurry; the fully foamed foam is then mixed into the slurry in the mixer, and fully stirred to form foam concrete, which is then poured into a rectangular mold to obtain a whole block embryo;

[0007] S2, whole embryo dehydration and initial culture

[0008] The prepared foam concrete blocks are placed in a static drying and primary curing room to complete dehydration and primary curing;

[0009] S3, embryo core cutting and molding

[0010] When the foam concrete block meets the strength grade, it is taken out and cut into several foam concrete blocks with a steel wire with a diameter of ≤1 mm. The length, width and height of the blocks after cutting are 10 mm smaller than the standard specifications. When the green body strength is ≥0.25Mpa, it can be used as the core material of high-strength composite lightweight blocks.

[0011] S4. Measuring and pre-mixing of coating raw materials

[0012] After accurate measurement of the dry raw materials according to the designed mix ratio of C25 strength grade, they are uniformly fed into the mixing device for pre-mixing for 2 minutes. Then, siliceous medium-fine sand with natural moisture content is added in proportion and mixing is continued for 3 minutes to fully mix the sand, powder and fiber.

[0013] S5. Atomization and water addition of coating powder material

[0014] Fresh water, water reducer and air entraining agent that meet the process requirements are injected into the atomizing water adding system of the stirring device, and the stirring device in the system fully stirs them to form a homogeneous liquid for use; after the coating materials are pre-mixed in the agitator device, the stirring device continues to work, and the atomizing water adding device starts to work, using compressed air to spray the homogeneous liquid through multiple nozzles into the running stirring device, and fully and evenly mix it with the coating materials that have been turning in the stirring device until the water addition is completed according to the water-cement ratio requirements;

[0015] S6, secondary lubrication of coating material

[0016] After the addition of water is completed, the coating raw materials are stirred in the stirrer for another 2 to 3 minutes, and then the stirring is stopped and the raw materials are allowed to stand in the high-speed stirring device for 3 to 5 minutes to complete the first-level lubrication; then the high-speed stirring device is started and the first-level lubricated raw materials are stirred again for 2 to 3 minutes, and then the stirring is stopped for 3 to 5 minutes to complete the second-level lubrication;

[0017] S7, dry hard coating material is sent into the material distribution bin

[0018] After the secondary lubrication, the coating material is in a loose, wet, dry and hard state. The discharging device of the stirring device is opened to send the mixed dry and hard coating material into the material distribution bin to complete the mixing of the coating material. Repeat the above steps S1 to S4 again to continuously complete the coating material mixing work and realize the flow operation.

[0019] S8, vibration coating on the bottom surface of the mold

[0020] A single or N-piece mold is placed and fixed on a vibration platform. The vibration platform locking device fixes the mold and the vibration platform starts working. Then the bottom coating material distribution device is started. After being measured by the material distribution metering device, 7-8mm dry hard coating material is evenly injected into the mold. Then, a horizontal rectangular vertical extrusion device that is slightly smaller than the bottom edge of the forming mold is quickly pressed into the mold. Under the action of vibration force and vertical pressure, the 4-6mm coating processing of the bottom surface of the mold is completed;

[0021] S9. Place the blank and fix it with a fixture

[0022] The pre-cut foamed concrete core with a strength of not less than 0.25MPa is placed into a single-piece or group forming mold with the bottom cladding completed by a horizontally movable core feeding device. During the core placement process, four sets of elastic clamps located in the middle and lower part of the mold side will be triggered to clamp the core to the center of the mold. At this time, the top surface of the core is 3-5mm lower than the horizontal top surface of the mold, and a uniform gap of 3-5mm is formed with the surrounding side of the mold.

[0023] S10, side gap vibration filling and compaction

[0024] The vibration platform and the side gap primary coating feeding device are started synchronously. After being measured by the feeding metering device, the dry hard material is unloaded onto the top surface of the green body in the mold. With the vibration force, it quickly fills the surrounding gaps. When the dry hard material fills the vertical gap between the mold and the green body, the horizontal rectangular ring located above the vibration platform

[0025] The vertical compaction die starts a rectangular annular compaction die that matches the gap around the green body, and presses it vertically downward to perform the initial compaction on the loose material injected into the vertical gap. After the pressure is applied, the compaction die is then lifted up, and the side gap secondary coating material distribution device is filled with dry hard material under the vibration state, and then the secondary compaction is performed through the horizontal rectangular annular vertical secondary compaction die. After the rectangular annular compaction die has compacted twice, the rectangular annular compaction die is lifted up to the non-working state. At this time, the unfilled depth of the gap around the core material does not exceed 20mm, and the side gap coating between the die and the green body is basically formed.

[0026] S11, Spinning Top Surface Covering

[0027] After the mold and the sides of the green body are compacted, the platform vibration is stopped, and the side gap top surface coating distribution device and the horizontal rectangular ring-shaped vertical secondary compaction mold supporting the pressure device are started. The device is a vertical telescopic eccentric structure, and the rotating scraper is slightly inclined at about 1° to the horizontal plane. After the scraper descends and contacts the material, it starts to rotate and continuously pressurize, scraping off the excess slurry on the top surface of the mold while achieving continuous spinning and polishing, forming a dense and smooth surface as the top surface coating of the green body;

[0028] S12, demoulding, grouping and palletizing

[0029] After the top surface coating is completed, the disassembly point of the mold is released, and the formed coating blocks are pushed away from the vibration platform through the coating block horizontal ejection device. The blocks are then grabbed by the palletizer and placed on the horizontal maintenance vehicle for palletizing, assembly and loading.

[0030] S13, autoclave curing

[0031] After the negative pressure forming of the composite insulation blocks is completed, the mold is opened directly on the vibration table, and the blocks are pushed out of the vibration table by a push-pull device. They are stacked by a suction cup stacker and sent to the steam curing kettle after stacking. The steam curing kettle is closed and vacuumed to 0-0.06MPa for 0.5h. Then, steam at a working pressure of 1.3MPa is injected, and the temperature is slowly raised to 193±5℃. The pressure is stabilized at 1.2MPa for 7.5h. Then, the steam curing system is closed and the pressure is slowly reduced for 20min to reduce the pressure in the steam curing kettle to normal pressure. At this time, the overall compressive strength of the blocks is ≥10MPa, which meets the factory conditions. The cured composite blocks can be stacked, packed, and loaded for transportation.

[0032] The advantages of the present invention over the prior art are: the present invention adopts an atomization and water addition process to solve the problems of uneven dryness and wetness of the coating powder material and agglomeration into larger particles caused by direct water addition, ensuring that the material is as loose and agglomerated as possible; the two-stage lubrication process of the coating material is adopted, which can promote the material to completely reach a homogeneous, moist and loose state; the present invention sets the core material coating process into three steps, the first step is to vibrate the coating on the bottom surface of the mold, the second step is to vibrate and fill the side gap to compact, and the third step is to fill the coating material again while vibrating. The step-by-step coating process can make the coating around the core material uniform and dense, avoid the defect of different density of the peripheral coating material products caused by one or two pressure forming, and realize industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a schematic diagram of a device and method for preparing a high-strength composite lightweight building block for a load-bearing structure.

[0034] Figure 2 The present invention is a schematic flow chart of a device and method for preparing a high-strength composite lightweight building block for a load-bearing structure. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0036] Example:

[0037] Combined with attachment Figure 1 A device for preparing high-strength composite lightweight blocks for load-bearing structures comprises a cladding forming area 1, a demoulding, cleaning and box-closing area 2, and a conveyor belt 3 running through the cladding forming area 1 and the demoulding, cleaning and box-closing area 2. The conveyor belt 3 has same-diameter redirecting rollers 4 at both ends. Several detachable forming molds 5 are arranged at intervals on the upper part of the conveyor belt 3. Elastic clamps extending into the molds 5 are arranged on the side walls around the molds 5. Bottom cladding material distributing devices 6 and horizontal rectangular blocks are arranged at intervals along the conveying direction of the conveyor belt 3 and above the molds 5 in the cladding forming area 1. The structure comprises a vertical extrusion device 7, a horizontally movable embryo core feeding device 8, a side gap primary coating distribution device 9, a horizontal rectangular annular vertical compaction mold 10, a side gap secondary coating distribution device 11, a horizontal rectangular annular vertical secondary compaction mold 12, a side gap top surface coating distribution device 13, and a horizontal rectangular annular vertical tertiary compaction mold 14. In the demoulding, cleaning, and box-closing area 2, a coating block horizontal ejection device 15, an empty mold horizontal cleaning device 16, and a release agent coating nozzle device 17 are arranged at intervals along the conveying direction of the conveyor belt 3 and above the mold 5.

[0038] A vibration platform 18 is provided on the inner side of the top of the transmission belt, just below the bottom coating distribution device 6, the side gap primary coating distribution device 9, the side gap secondary coating distribution device 11, and the side gap top coating distribution device 13;

[0039] A pressure platform 19 is provided on the inner side of the top of the transmission belt, directly below the horizontal rectangular vertical extrusion device 7, the horizontal rectangular annular vertical secondary compaction die 12, and the horizontal rectangular annular vertical tertiary compaction die 14;

[0040] A non-pressure-bearing platform 20 is provided on the inner side of the top of the transmission belt, directly below the horizontally movable embryo core feeding device 8 and the cladding block transverse ejecting device 15 .

[0041] Several pressure rollers 21 are arranged at intervals on the inner side of the top of the transmission belt, and a same-speed empty mold rotary supporting and conveying device 22 is arranged at the bottom of the top of the transmission belt and below the mold 5.

[0042] Combined with attachment Figure 2 This embodiment also discloses a method for preparing a high-strength composite lightweight building block for a load-bearing structure, comprising the following steps:

[0043] S1. Foaming of core material

[0044] The core material raw materials including ordinary Portland cement, ground water slag powder, ground lime powder, and sieved granite saw mud are premixed in a mixer; high-concentration naphthalene water reducer and composite air-entraining agent are evenly mixed with mixing water, and then stirred with the former to form a slurry for standby use; the composite air-entraining agent and foaming agent are diluted with 40 to 45 times of water, and foamed using a foaming machine to form a foam slurry, and then the fully foamed foam is mixed into the slurry in the mixer, and fully stirred to form foam concrete, which is then poured into a rectangular mold 5 to obtain a whole block embryo;

[0045] S2, whole embryo dehydration and initial culture

[0046] The prepared foam concrete block is placed in a static drying and primary curing room to complete dehydration and primary curing; the temperature in the drying and primary curing room is maintained at 65-85°C, and the dehydration and primary curing are carried out for 4-6 hours, and the water-cement ratio of the whole block is controlled at 0.13-0.18. At this time, the strength of the whole block can reach 0.12-0.16Mpa;

[0047] S3, embryo core cutting and molding

[0048] When the foam concrete block meets the strength grade, it is taken out and cut into several foam concrete blocks with a steel wire with a diameter of ≤1 mm. The length, width and height of the blocks after cutting are 10 mm smaller than the standard specifications. When the green body strength is ≥0.25Mpa, it can be used as the core material of high-strength composite lightweight blocks.

[0049] S4. Measuring and pre-mixing of coating raw materials

[0050] The dry raw materials including cement, slag powder, ground fly ash, granite sawdust powder and reinforcing fiber are precisely measured according to the designed mix ratio of C25 strength grade and uniformly fed into the mixing device for premixing for 2 minutes. Then, siliceous medium-fine sand with natural moisture content is added in proportion and mixing is continued for 3 minutes to fully mix the sand, powder and fiber.

[0051] S5. Atomization and water addition of coating powder material

[0052] Fresh water, water reducer and air entraining agent that meet the process requirements are injected into the atomizing water adding system of the stirring device, and the stirring device in the system fully stirs them to form a homogeneous liquid for use; after the coating materials are pre-mixed in the agitator device, the stirring device continues to work, and the atomizing water adding device starts to work, using compressed air to spray the homogeneous liquid through multiple nozzles into the running stirring device, and fully and evenly mix it with the coating materials that have been turning in the stirring device until the water addition is completed according to the water-cement ratio requirements;

[0053] S6, secondary lubrication of coating material

[0054] After the addition of water is completed, the coating raw materials are stirred in the stirrer for another 2 to 3 minutes, and then the stirring is stopped and the raw materials are allowed to stand in the high-speed stirring device for 3 to 5 minutes to complete the first-level lubrication; then the high-speed stirring device is started and the first-level lubricated raw materials are stirred again for 2 to 3 minutes, and then the stirring is stopped for 3 to 5 minutes to complete the second-level lubrication;

[0055] S7, dry hard coating material is sent into the material distribution bin

[0056] After the secondary lubrication, the coating material is in a loose, wet, dry and hard state. The discharging device of the stirring device is opened to send the mixed dry and hard coating material into the material distribution bin to complete the mixing of the coating material. Repeat the above steps S1 to S4 again to continuously complete the coating material mixing work and realize the flow operation.

[0057] S8, vibrating the bottom surface of mold 5

[0058] A single or N-piece mold 5 is placed and fixed on a vibration platform 18. The mold 5 is fixed by the locking device of the vibration platform 18. The vibration platform 18 starts working, and then the bottom coating material distribution device 6 is started. After being measured by the distribution metering device, 7 to 8 mm of dry hard coating material is evenly injected into the mold 5. Then, the horizontal rectangular vertical extrusion device 7, which is slightly smaller than the bottom edge of the forming mold 5, is quickly pressed into the mold 5. Under the action of vibration force and vertical pressure, the 4 to 6 mm coating processing of the bottom surface of the mold 5 is completed;

[0059] S9. Place the blank and fix it with a fixture

[0060] A pre-cut foamed concrete core with a strength of not less than 0.25 MPa is placed into a single or group forming mold 5 with a finished bottom cladding by a horizontally movable core feeding device 8. During the core placement process, four sets of elastic clamps located in the middle and lower part of the side of the mold 5 are activated to clamp the core to the center of the mold 5. At this time, the top surface of the core is 3 to 5 mm lower than the horizontal top surface of the mold 5, and a uniform gap of 3 to 5 mm is formed with the surrounding side surfaces of the mold 5.

[0061] S10, side gap vibration filling and compaction

[0062] The vibration platform 18 and the side gap primary coating material distribution device 9 are started synchronously. After being measured by the material distribution device, the dry hard material is discharged to the top surface of the green body in the mold 5. With the vibration force, it quickly fills the surrounding gaps. When the dry hard material fills the vertical gap between the mold 5 and the green body, the horizontal rectangular ring located above the vibration platform 18

[0063] The vertical compaction die 5 starts the rectangular annular compaction die 5 that is adapted to the gap around the green body, and presses it vertically downward to perform the initial compaction on the loose material injected into the vertical gap. After the pressure is applied, the compaction die 5 is then lifted up, and the side gap secondary coating material distribution device 11 is filled with dry hard material under the vibration state, and then the horizontal rectangular annular vertical secondary compaction die 12 is used for secondary compaction. After the rectangular annular compaction die 5 has compacted twice, the rectangular annular compaction die 5 is lifted up to the non-working state. At this time, the unfilled depth of the gap around the core material does not exceed 20 mm, and the side gap coating between the die 5 and the green body is basically formed.

[0064] S11, Spinning Top Surface Covering

[0065] After the mold 5 is compacted with the sides of the green body, the platform vibration is stopped, and the side gap top surface coating distribution device 13 and the horizontal rectangular ring-shaped vertical secondary compaction mold 12 supporting the pressure device are started. The device is a vertical telescopic eccentric structure, and the rotating scraper is slightly inclined at about 1° to the horizontal plane. After the scraper descends and contacts the material, it starts to rotate and continuously pressurize, scraping off the excess slurry on the top surface of the mold 5 while achieving continuous spinning and polishing, forming a dense and smooth surface as the green body top surface coating;

[0066] S12, demoulding, grouping and palletizing

[0067] After the top surface coating is completed, the disassembly point of the mold 5 is released, and the formed coating blocks are pushed away from the vibration platform 18 through the coating block horizontal ejection device 15, and then grabbed by the stacking machine and placed on the horizontal maintenance vehicle for stacking, assembly and loading;

[0068] S13, autoclave curing

[0069] After the negative pressure forming of the composite insulation building blocks is completed, the mold 5 is opened directly on the vibration table, and the building blocks are pushed out of the vibration table by the push-pull device. The building blocks are stacked by the suction cup stacker. After stacking, they are sent to the steam curing kettle, the steam curing kettle is closed, and the vacuum is 0-0.06MPa for 0.5h. Then, steam at a working pressure of 1.3MPa is injected, and the temperature is slowly raised to 193±5℃. The pressure is stabilized at 1.2MPa for 7.5h, and then the steam curing system is closed and the pressure is slowly reduced for 20min to reduce the pressure in the steam curing kettle to normal pressure. At this time, the overall compressive strength of the building blocks is ≥10MPa, which meets the factory conditions. The cured composite building blocks can be stacked, packaged, and loaded for transportation.

[0070] In specific implementation, the new high-strength composite lightweight building block shown in the present invention consists of two parts: a covering layer and a core material, wherein the covering layer is made of powder concrete with a dry bulk density of ≤2200 / m 3 ; The core material is foamed concrete, dry density ≤750kg / m 3The specifications of the composite building blocks are the same as the standard specifications of the foamed concrete building blocks. The core material cutting size is 10mm smaller in length, width and height than the standard specifications. The average thickness of the core material outer covering is about 5mm; the compressive strength grade of the covering material is ≥20MPa, the compressive strength of the core material is ≥7.5MPa, and the overall compressive strength of the building block is ≥12.5MPa. The dry bulk density of the composite lightweight building block of this embodiment is ≤900kg / m 3 , which meets the dry density requirements of lightweight blocks; since the composite block adopts the integrated production technology of core material and external pressure-bearing covering, the core material and the surface layer are firmly bonded, and there is no possibility of peeling off, and it is an integrated steam-cured kettle curing, and there is no powder and weak particles on the masonry surface. Although the surface of the block is smoother than that of a single aerated concrete block, the bonding strength with the masonry mortar and the plastering mortar is still much better than that of the foamed concrete, and it can form an overall load-bearing structure after masonry to achieve the load-bearing purpose; since the block covering is extremely thin, only about 5mm, and its core material is pure foamed concrete, it is entirely possible to use masonry mortar with fine sand configuration, and control the horizontal mortar joint of the block to about 8mm. Under the process conditions of controlling the mortar joint, the equal-thickness masonry built by the high-strength composite block and the traditional aerated concrete masonry have basically the same effect in terms of masonry dry density, thermal insulation, sound insulation, etc.

[0071] 1. Process characteristics of the present invention

[0072] 1. Atomization and water addition of coating powder material

[0073] In order to prepare dry and hard coating powder materials with ultra-low moisture content, the present invention takes the lead in adopting an atomization and water-adding process. Fresh water, water-reducing agent, air-entraining agent, etc. that meet the process requirements are injected into the atomization and water-adding system of the stirring device in proportion, and the stirring device in the system fully stirs them to form a homogeneous liquid for standby use; after the coating raw materials are pre-mixed in the stirrer device, the stirring device continues to work, and the atomization and water-adding device starts to work, using compressed air to spray the homogeneous liquid through multiple nozzles into the running stirring device, and fully and evenly mix it with the FRC raw materials that have been turning in the stirring device, solving the problem of uneven dryness and wetness of the coating powder materials and agglomeration into larger particles caused by direct water addition, and ensuring that the material is as loose and non-agglomerated as possible;

[0074] 2. Two-stage lubrication process

[0075] In order to ensure the density and molding effect of the coating around the core material, the present invention has created a two-stage lubrication process for the coating material. That is, after the atomization and water addition are completed, the FRC raw material is stirred in the stirrer for another 2 to 3 minutes to further mix the dry and wet materials, and then the stirring is stopped and the raw material is allowed to stand in the high-speed stirring device for 3 to 5 minutes. During the static stacking process, the material is allowed to penetrate and infiltrate further than the wet material, promoting the uniformity of dry and wet materials, completing the first-stage lubrication; then the high-speed stirring device is started again, and the raw material that has been lubricated in the first stage is stirred again for 2 to 3 minutes to further homogenize the dry and wet materials, and then the stirring is stopped and the material is allowed to stand for 3 to 5 minutes to promote the material to completely reach a homogenous, moist and loose state, completing the second stage lubrication;

[0076] 3. Step-by-step coating process

[0077] To achieve industrial production, the present invention's core cladding process consists of three steps. The first step involves vibrating the bottom surface of the mold 5. The removable mold 5 is secured to a vibrating platform 18. While vibrating, a 7-8 mm thick layer of dry, hard cladding material is evenly injected into the mold 5 via a distribution device. A vertical pressure device above the vibrating platform 18 rapidly presses a horizontal rectangular extrusion device into the mold 5. The combined effects of vibration and vertical pressure complete the 4-6 mm cladding of the bottom surface of the mold 5. The second step involves vibrating and compacting the side gaps. The pre-prepared, cut, and shaped foamed concrete core is placed into the mold 5. Four sets of elastic clamps located in the lower middle section of the mold 5's sides activate, pressing the core to the center of the mold 5, creating a uniform 4-5 mm gap with the inner surface of the mold 5. The coating material is injected while vibrating until the gap is filled. The vertical rectangular annular compacting mold 5 located above the vibration platform 18 is aligned with the gap position and pressed downward to compact the loose material filled for the first time. After the compacting device is lifted, it continues to vibrate and fill the loose material in the gap around the core material and the mold 5 again. It is pressed into the rectangular annular compacting mold 5 again to complete the secondary compaction. At this time, the unfilled depth of the gap around the core material does not exceed 20mm; the third step is to fill the coating material again while vibrating, slightly higher than the top surface of the mold 5, stop the platform vibration, and start the compaction rotary scraper of the pressure device. The device is a vertical telescopic eccentric structure, and the rotating scraper is slightly inclined at about 1° to the horizontal plane. After the scraper descends to contact with the material, it starts to rotate and continuously pressurizes to scrape off the excess slurry on the top surface of the mold 5 while realizing continuous spinning to form a dense and smooth finish as the top surface coating of the blank. The step-by-step cladding process can make the cladding around the core material uniform and dense, avoiding the defect of uneven density of the surrounding cladding material caused by one or two pressure forming.

[0078] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A device for preparing high-strength composite lightweight building blocks for load-bearing structures, characterized in that: It includes a cladding forming area, a demoulding, cleaning and box closing area, and a conveyor belt running through the cladding forming area and the demoulding, cleaning and box closing area. The conveyor belt is provided with same-diameter redirecting rollers at both ends. A plurality of detachable forming molds are spaced apart on the upper part of the conveyor belt. In the cladding forming area, a bottom cladding material distribution device, a horizontal rectangular vertical extrusion device, a horizontally movable embryo core feeding device, a side gap primary cladding material distribution device, a horizontal rectangular annular vertical compaction mold, a side gap secondary cladding material distribution device, a horizontal rectangular annular vertical secondary compaction mold, a side gap top cladding material distribution device, and a horizontal rectangular annular vertical tertiary compaction mold are spaced apart along the conveying direction of the conveyor belt and located above the mold. In the demoulding, cleaning and box closing area, a cladding block lateral ejection device, an empty mold lateral cleaning device, and a release agent coating nozzle device are spaced apart along the conveying direction of the conveyor belt and located above the mold. A vibration platform is provided on the inner side of the top of the conveyor belt, directly below the bottom coating distribution device, the side gap primary coating distribution device, the side gap secondary coating distribution device, and the side gap top coating distribution device; A pressure platform is provided on the inner side of the top of the conveyor belt, directly below the horizontal rectangular vertical extrusion device, the horizontal rectangular annular vertical secondary compaction die, and the horizontal rectangular annular vertical tertiary compaction die; A non-pressure-bearing platform is provided on the inner side of the top of the conveyor belt, directly below the horizontally movable embryo core feeding device and the cladding block transverse ejecting device.

2. The device for preparing high-strength composite lightweight building blocks for load-bearing structures according to claim 1, characterized in that: A plurality of pressure rollers are arranged at intervals on the inner side of the top of the conveyor belt, and a same-speed empty mold rotary supporting and conveying device is arranged at the bottom of the top of the conveyor belt and at a position below the mold.

3. The device for preparing high-strength composite lightweight building blocks for load-bearing structures according to claim 1, characterized in that: Elastic clamps extending into the mold are respectively arranged on the side walls around the mold.

4. A method for preparing high-strength composite lightweight building blocks for load-bearing structures, characterized in that: The following steps are involved: S1. Foaming of core material The core material raw materials are pre-mixed uniformly in a mixer; high-concentration naphthalene water-reducing agent, composite air-entraining agent and mixing water are uniformly mixed, and then mixed with the former to form a slurry for standby use; the composite air-entraining agent and foaming agent are diluted with 40-45 times water, and foamed using a foaming machine to form a foam slurry; the fully foamed foam is then mixed into the slurry in the mixer, fully stirred to form foam concrete, and poured into a rectangular mold to obtain a whole block embryo; S2, whole embryo dehydration and initial culture The prepared foam concrete blocks are placed in a static drying and primary curing room to complete dehydration and primary curing; S3, embryo core cutting and molding When the foam concrete block meets the strength grade, it is taken out and cut into several foam concrete blocks with a steel wire with a diameter of ≤1 mm. The length, width and height of the blocks after cutting are 10 mm smaller than the standard specifications. When the green body strength is ≥0.25Mpa, it can be used as the core material of high-strength composite lightweight blocks. S4. Measuring and pre-mixing of coating raw materials After accurate measurement of the dry raw materials according to the designed mix ratio of C25 strength grade, they are uniformly fed into the mixing device for pre-mixing for 2 minutes. Then, siliceous medium-fine sand with natural moisture content is added in proportion and mixing is continued for 3 minutes to fully mix the sand, powder and fiber. S5. Atomization and water addition of coating powder material Fresh water, water reducer and air entraining agent that meet the process requirements are injected into the atomizing water adding system of the stirring device, and the stirring device in the system fully stirs them to form a homogeneous liquid for use; after the coating materials are pre-mixed in the agitator device, the stirring device continues to work, and the atomizing water adding device starts to work, using compressed air to spray the homogeneous liquid through multiple nozzles into the running stirring device, and fully and evenly mix it with the coating materials that have been turning in the stirring device until the water addition is completed according to the water-cement ratio requirements; S6, secondary lubrication of coating material After the addition of water is completed, the coating raw materials are stirred in the stirrer for another 2 to 3 minutes, then the stirring is stopped and the raw materials are allowed to stand in the high-speed stirring device for 3 to 5 minutes to complete the first-level lubrication; then the high-speed stirring device is started and the first-level lubricated raw materials are stirred again for 2 to 3 minutes, and then the stirring is stopped for 3 to 5 minutes to complete the second-level lubrication; S7, dry hard coating material is sent into the material distribution bin After the secondary lubrication, the coating material is in a loose, wet, dry and hard state. The discharging device of the stirring device is opened to send the mixed dry and hard coating material into the distribution bin to complete the mixing of the coating material. Repeat the above steps S1 to S4 again to continuously complete the coating material mixing work and realize the flow operation. S8, vibration coating on the bottom surface of the mold A single or N-piece mold is placed and fixed on a vibration platform. The vibration platform locking device fixes the mold and the vibration platform starts working. Then the bottom coating feeding device is started. After being measured by the feeding metering device, 7-8mm dry hard coating material is evenly injected into the mold. Then, a horizontal rectangular vertical extrusion device that is slightly smaller than the bottom edge of the forming mold is quickly pressed into the mold. Under the action of vibration force and vertical pressure, the 4-6mm coating processing of the bottom surface of the mold is completed; S9. Place the blank and fix it with a fixture The pre-cut foamed concrete core with a strength of not less than 0.25MPa is placed into a single-piece or grouped forming mold with the bottom cladding completed by a horizontally movable core feeding device. During the core placement process, four sets of elastic clamps located in the middle and lower part of the mold side will be triggered to press the core to the center of the mold. At this time, the top surface of the core is 3-5mm lower than the horizontal top surface of the mold, and a uniform gap of 3-5mm is formed with the surrounding side of the mold. S10, side gap vibration filling and compaction The vibration platform and the side gap primary coating feeding device are started synchronously. After being measured by the feeding metering device, the dry hard material is unloaded onto the top surface of the green body in the mold. With the vibration force, it quickly fills the surrounding gaps. When the dry hard material fills the vertical gap between the mold and the green body, the horizontal rectangular ring located above the vibration platform The vertical compaction die starts a rectangular annular compaction die that matches the gap around the green body, and presses it vertically downward to perform the initial compaction on the loose material injected into the vertical gap. After the pressure is applied, the compaction die is then lifted up, and the side gap secondary coating material distribution device is filled with dry hard material under the vibration state, and then the secondary compaction is performed through the horizontal rectangular annular vertical secondary compaction die. After the rectangular annular compaction die has compacted twice, the rectangular annular compaction die is lifted up to the non-working state. At this time, the unfilled depth of the gap around the core material does not exceed 20mm, and the side gap coating between the die and the green body is basically formed. S11, Spinning Top Surface Covering After the mold and the sides of the green body are compacted, the platform vibration is stopped, and the side gap top surface coating distribution device and the horizontal rectangular ring-shaped vertical secondary compaction mold supporting the pressure device are started. The device is a vertical telescopic eccentric structure, and the rotating scraper is slightly inclined at about 1° to the horizontal plane. After the scraper descends and contacts the material, it starts to rotate and continuously pressurize, scraping off the excess slurry on the top surface of the mold while achieving continuous spinning and polishing, forming a dense and smooth surface as the top surface coating of the green body; S12, demoulding, grouping and palletizing After the top surface coating is completed, the disassembly point of the mold is released, and the formed coating blocks are pushed away from the vibration platform through the coating block horizontal ejection device. The blocks are then grabbed by the palletizer and placed on the horizontal maintenance vehicle for palletizing, assembly and loading. S13, autoclave curing After the negative pressure forming of the composite insulation blocks is completed, the mold is opened directly on the vibration table, and the blocks are pushed out of the vibration table by a push-pull device. They are stacked by a suction cup stacker and sent to the steam curing kettle after stacking. The steam curing kettle is closed and vacuumed to 0-0.06MPa for 0.5h. Then, steam at a working pressure of 1.3MPa is injected, and the temperature is slowly raised to 193±5℃. The pressure is stabilized at 1.2MPa for 7.5h. Then, the steam curing system is closed and the pressure is slowly reduced for 20min to reduce the pressure in the steam curing kettle to normal pressure. At this time, the overall compressive strength of the blocks is ≥10MPa, which meets the factory conditions. The cured composite blocks can be stacked, packed, and loaded for transportation.

5. The method for preparing a high-strength composite lightweight building block for a load-bearing structure according to claim 4, characterized in that: The core material raw materials include ordinary Portland cement, ground slag powder, ground lime powder, and sieved granite saw mud.

6. The method for preparing a high-strength composite lightweight building block for a load-bearing structure according to claim 4, characterized in that: The temperature in the drying and initial curing room is maintained at 65-85° C., and the dehydration and initial curing are performed for 4-6 hours, and the water-cement ratio of the whole embryo is controlled at 0.13-0.

18. At this time, the strength of the whole embryo can reach 0.12-0.16 MPa.

7. The method for preparing a high-strength composite lightweight building block for a load-bearing structure according to claim 4, characterized in that: The dry raw materials include cement, water slag powder, ground fly ash, granite sawdust powder, and reinforcing fiber.

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