A fast-hardening cementitious material mixing and construction device and control method

Abstract

The application discloses a fast-hardening cementing material stirring construction equipment and a control method thereof. The equipment comprises a mobile base, a turnover forced stirring host, a variable frequency speed regulation system, a tilting unloading mechanism, a flow guide chute and a material receiving construction trolley with a retractable gate. The top opening of the stirring host cylinder serves as a discharge port. The variable frequency speed regulation system provides a high-speed stirring gear and a low-speed active maintenance gear. The material is directly poured through the large-diameter opening at the top of the cylinder and is unloaded into the trolley through the flow guide chute. After the trolley is pushed to a construction point, the gate is retracted and the trolley body is tilted to realize paving into a mold. The control method is to first stir at high speed to fully disperse the powder, then switch to low-speed active maintenance to maintain a workable state, and then pave after unloading. The application is characterized by extremely short setting time of fast-hardening materials. High-speed dispersion, overall tilting unloading to avoid blockage, and fast paving of the trolley to shorten the construction time are provided. Manual and automatic implementation modes are provided, and the application is suitable for small-quantity fast construction scenes such as road emergency repair.

Description

Technical Field

[0001] This invention relates to the field of construction equipment technology for building materials, specifically to a mixing and construction equipment and control method for fast-setting cementitious materials. Background Technology

[0002] Phosphate cement (also known as magnesium phosphate cement, MPC), as a new type of rapid repair material, possesses excellent properties such as high early strength (strength can reach over 20 MPa after 2 hours), good bonding performance, low-temperature resistance, and good volume stability. It is widely used for emergency repairs and rapid restorations of roads, bridges, airport runways, military facilities, and other engineering projects. However, the hydration reaction of phosphate cement is intense and exothermic, resulting in an extremely short setting time (typically 10-30 minutes). From mixing with water to casting, the effective working time is extremely limited. This inherent characteristic imposes extremely stringent time constraints on on-site construction. This not only places far greater demands on construction organization than ordinary cement materials but also fundamentally restricts the large-scale engineering application of this material in scenarios such as emergency road repairs.

[0003] The existing technology has the following prominent problems: First, there is the transportation challenge. In the traditional construction model of "centralized mixing at commercial concrete plant → tanker transportation → on-site pouring," the materials solidify during transportation. Even if retarders are added to extend the setting time, it is only enough to complete loading and short-distance transportation, leaving no construction window after arrival at the site.

[0004] Secondly, existing mobile mixing equipment is large in size and expensive. Although existing mobile concrete mixing plants on the market have achieved vehicle-mounted mobility, the equipment is bulky (the capacity of a single batch is mostly over 1m³), expensive (usually 500,000 to 1 million yuan), and weighs several tons to tens of tons. Transportation and relocation require special trailers, which is not suitable for the construction characteristics of road emergency repairs that are "numerous, wide-ranging, and small in volume".

[0005] Third, the existing mixing equipment operates at excessively low speeds, failing to match the setting characteristics of rapid-setting materials. Most existing mixing equipment is modified from ordinary concrete mixers, with mixing speeds typically only 20-40 r / min. For rapid-setting cementitious materials with a setting time of only 10-30 minutes, the time window from adding water to initial setting is extremely limited. At low speeds of 20-40 r / min, the powder and water cannot be sufficiently and evenly dispersed before initial setting, resulting in a large number of powder agglomerates, uneven hydration reaction, and a final strength far below the design value. Studies have shown that the mixing time for rapid-setting cementitious materials must be controlled within 3 minutes, and a mixing speed of ≥250 r / min is required to achieve sufficient dispersion of the powder within such a short time.

[0006] Fourth, automated equipment is incompatible with rapid-hardening materials. Some existing technologies attempt to improve the "intelligence" of equipment by integrating modules such as automatic weighing, automatic feeding, electronic flow meters, PLC control systems, and high-pressure cleaning pumps. However, through extensive field testing, the inventors found that these automated modules not only fail to improve efficiency in high-frequency, small-volume rapid-hardening material applications but also produce serious negative effects. Numerous mechanical gaps and residual dead zones exist inside the screw conveyor and electronic weighing hopper, making it extremely difficult to clean the rapidly hardening material after solidification, leading to equipment blockage and failure after only 2-3 batches. Furthermore, the complex circuitry and sensors have a high failure rate in harsh field construction environments.

[0007] Fifth, the unloading method is not suitable for the characteristics of fast-setting materials. Existing mixing equipment mostly uses bottom butterfly valves or pneumatic valves for unloading, with narrow discharge ports (usually no more than 200mm in diameter). Fast-setting cementitious materials are easily left behind and solidify rapidly when passing through narrow valves, causing the valve to jam. Even with large-diameter valves, the problem of material residue at the valve body sealing surface cannot be fundamentally solved.

[0008] Sixth, there is a disconnect between the material discharge and construction processes. Existing equipment only performs the mixing function; after discharge, the material still needs to be manually shoveled and spread, a process that takes at least 2-5 minutes. For fast-setting materials with a setting time of only 10-20 minutes, this time loss severely squeezes the effective construction window, often causing the material to lose its fluidity during the spreading process.

[0009] To address the aforementioned issues, some patents have explored solutions. CN110281393A discloses a frequency conversion mixing process for ultra-high performance concrete, but this patent only addresses the mixing process itself and does not solve the problems of mobile construction and compatibility with fast-setting materials. CN202310613705.X ​​discloses a mobile automatic mixing device for quick-setting concrete, but it still retains a complex automatic feeding and cleaning mechanism, resulting in a relatively high size and cost. CN114905627A discloses a mixing device for magnesium phosphate cement, but it is a fixed structure and lacks mobile construction capabilities.

[0010] Therefore, developing a field construction equipment for fast-setting cementitious materials that can meet the needs of rapid construction in small volumes and accommodate different application scenarios has significant engineering application value and urgent market demand. Summary of the Invention In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a mixing and construction equipment for quick-setting cementitious materials that meets the needs of small-volume rapid construction and can also take into account different application scenarios.

[0011] The technical solution adopted in this invention is as follows: A quick-setting cementitious material mixing and construction equipment, comprising: A mobile base, with wheels at the bottom, is used to move and position the equipment on the construction site; The tilting forced mixing host is installed on the mobile base and includes a mixing cylinder, a mixing shaft and mixing blades disposed in the mixing cylinder, and a variable frequency motor for driving the mixing shaft to rotate; the top of the mixing cylinder is provided with a powder feeding port and a water inlet; the discharge port of the mixing cylinder is the opening at the top of the cylinder. The variable frequency speed control system includes a speed control control unit and a frequency converter. The speed control control unit is electrically connected to the frequency converter, and the frequency converter is electrically connected to the variable frequency motor. The variable frequency speed control system (3) is configured to adjust the speed of the stirring shaft (22) to a high-speed stirring gear of 250-350 r / min and a low-speed holding gear of 50-100 r / min. The water metering system is used to add metered mixing water into the mixing drum. The tilting and unloading mechanism includes a tilting bracket fixedly installed on a movable base, a rotating shaft disposed on the outer wall of the mixing cylinder, and a tilting drive device for driving the rotating shaft to rotate. The mixing cylinder is rotatably installed on the tilting bracket via the rotating shaft. Under the action of the tilting drive device, the mixing cylinder can switch between a vertical mixing position and an inclined unloading position around the rotating shaft. During unloading, the mixing cylinder is tilted as a whole, and the material is directly tilted out through the opening at the top of the cylinder. A guide chute is set at the edge of the discharge port of the mixing drum to guide the mixed material to the receiving construction trolley when the material is being unloaded at an inclined unloading position. The material receiving and construction trolley includes a vehicle body, wheels located at the bottom of the vehicle body, and a removable gate located on one side of the vehicle body; the vehicle body receives the mixed material unloaded from the guide chute and moves to the construction point, and the mixed material is spread into the formwork by removing the gate and tilting the vehicle body. The cooling and temperature control system includes a water-cooled jacket installed on the outer wall of the mixing drum and a temperature sensor installed inside the mixing drum. The water-cooled jacket is connected to an external circulating cooling water source, and the temperature sensor is electrically connected to a controller. The system is used to monitor the temperature of the slurry in real time during the mixing process and to trigger an alarm when the temperature exceeds a set value.

[0012] In a preferred embodiment of the present invention, the stirring blade is a high-shear turbine blade or a serrated disc blade, the gap between the blade and the inner wall of the stirring cylinder is 5-8 mm, and the blade linear velocity is ≥4 m / s.

[0013] In a preferred embodiment of the present invention, the tilting drive device is a manual tilting drive assembly or an automatic tilting drive assembly; The manual tilting drive assembly consists of a worm gear reducer and a hand crank. The worm gear reducer has a self-locking function. The mixing cylinder can be switched between a vertical position and an inclined position and stopped at any tilt angle by manual cranking. The automatic tilting drive component is an electric push rod or a hydraulic cylinder, which is controlled by a controller to realize the automatic tilting and resetting of the mixing cylinder.

[0014] In a preferred embodiment of the present invention, the inner wall of the material receiving construction trolley is provided with a non-stick coating, which is a polytetrafluoroethylene coating or a ceramic coating; the depth of the trolley body does not exceed 0.3 meters, and the bottom is flat; the retractable gate is provided with guide grooves on both sides, and the gate slides up and down along the guide grooves to open and close; the top of the gate is provided with a handle. The inner wall of the stirring cylinder is provided with a non-stick coating, which is a polytetrafluoroethylene coating; the stirring blades are installed on the stirring shaft by quick-release bolts.

[0015] In a preferred embodiment of the present invention, the mobile base is provided with an integrated tool rack, which includes at least one scraper rack, one vibrator rack, and one spray bottle rack, and the rack has a spring-loaded snap-fit ​​structure; the mobile base is also provided with a storage platform and a forklift hole; the wheels are omnidirectional wheels with braking devices; and the four corners of the mobile base are also provided with adjustable support legs, which have a screw-lifting type or a hydraulic jack type structure.

[0016] In a preferred embodiment of the present invention, the water supply metering system uses a quantitative container with a capacity scale or an automatic water supply metering component. The metering container is used for manually measuring and adding the mixing water; Automatic water metering components include a water tank, water supply pipeline, a flow meter or electronic scale installed on the water supply pipeline, and a solenoid valve, with the water supply volume automatically controlled by a controller.

[0017] As a preferred embodiment of the present invention, it also includes an automatic feeding system and a high-pressure automatic cleaning system. The automatic feeding system includes a powder silo, a screw conveyor and a weighing device, which are used to automatically feed metered powder into the mixing drum. The high-pressure automatic cleaning system includes a high-pressure water pump, a flushing pipeline, and nozzles installed on the inner wall of the mixing drum. The flushing pressure of the high-pressure automatic cleaning system is ≥5 MPa, and it is used to flush the inner wall of the mixing drum and the mixing blades after each batch of material is unloaded.

[0018] In a preferred embodiment of the present invention, the top of the mixing cylinder is provided with a cover plate, and the cover plate is provided with an observation window and a powder feeding port; a mechanical seal or a double-lip skeleton oil seal is provided between the mixing shaft and the mixing cylinder.

[0019] This invention also provides a control method for mixing and constructing rapid-setting cementitious materials using the equipment described above, comprising the following steps: S1: Move the equipment to the construction site and position it; S2: Add the pre-mixed quick-setting cementitious dry powder into the mixing drum and add a measured amount of mixing water; S3: The material is stirred and dispersed at high speed in a high-speed stirring mode of 250-350 r / min by the speed control unit for 1-2 minutes. S4: By using the speed control unit, switch the mixing speed to a low-speed maintenance mode of 50-100 r / min to perform low-speed maintenance mixing and keep the mixture in a workable state. S5: Place the material receiving trolley under the guide chute, and use the tilting drive device to tilt the mixing cylinder and unload the mixed material into the material receiving trolley through the guide chute. S6: Push the material receiving trolley to the construction point, remove the removable gate on the side wall of the trolley, and tilt the trolley body at the same time so that the mixed material flows out under gravity and is spread into the formwork. S7: After construction is completed, clean the mixing drum and the material receiving trolley.

[0020] Compared with the prior art, the present invention has the following advantages: 1. This invention proposes a targeted solution based on the material characteristics of rapid-setting cementitious materials, which have a setting time of only 10-30 minutes and a stirring window of ≤3 minutes. The stirring speed is increased to 250-350 r / min, significantly higher than the 20-40 r / min of traditional stirring equipment. At this high speed, the rapid-setting cementitious material powder and water can achieve sufficient and uniform dispersion within 1-2 minutes, preventing the formation of powder agglomerates and ensuring the uniformity of the hydration reaction and the final strength of the material.

[0021] 2. The traditional bottom butterfly valve unloading method has been abandoned. Instead, the entire barrel is tilted for unloading. The discharge port is the large-diameter opening of the barrel (diameter ≥ 0.7m). There are no narrow valves or sealing gaps, which solves the problem of solidification and clogging of the equipment by fast-hardening materials at the discharge port.

[0022] 3. The removable gate allows for precise material placement and paving, reducing the traditional 2-5 minutes of manual shoveling and paving to less than 30 seconds, perfectly matching the 10-20 minute setting window of fast-setting materials.

[0023] 4. The stepless adjustment of stirring speed is achieved through frequency conversion speed regulation. The two-stage stirring process of high-speed dispersion and low-speed retention, combined with the material setting-regulating components, achieves dual control of setting time, providing sufficient operating window for on-site construction.

[0024] 5. This invention provides both manual and automatic operation methods. The simplified manual version features a compact structure, low manufacturing cost, and convenient relocation, making it suitable for small-volume, multi-site construction scenarios such as emergency road repairs. The integrated automatic version is equipped with modules for automatic material feeding, PLC control, and automatic cleaning, making it suitable for larger-scale continuous construction scenarios. Both solutions share the same core structure for tipping unloading and receiving paving, exhibiting good technical uniformity and market adaptability. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the fast-setting cementitious material mixing and construction equipment of the present invention; Figure 2 This is a schematic diagram of the control method for the quick-setting cementitious material mixing and construction equipment of the present invention. Figure 3 This is a schematic diagram of the material receiving trolley in Embodiment 5 of the fast-setting cementitious material mixing and construction equipment of the present invention; Figure 4 This is a schematic diagram of the material receiving trolley unloading material in Embodiment 5 of the fast-setting cementitious material mixing and construction equipment of the present invention.

[0026] The reference numerals in the attached drawings include: 1—movable base; 11—wheels; 12—storage platform; 13—braking device; 14—forklift hole; 15—support leg; 21—mixing cylinder; 22—mixing shaft; 23—mixing blades; 24—variable frequency motor; 25—powder feeding port; 26—water inlet; 3—variable frequency speed control system; 41—quantitative container; 5—tilting unloading mechanism; 51—tilting bracket; 52—rotating shaft; 53—tilting drive device; 6—guide chute; 71—vehicle body; 72—wheels; 73—removable gate; 8—tool integrated rack; 91—drive motor; 92—lead screw; 93—slider; 94—connecting frame; 95—push plate; 96—movable door. Detailed Implementation

[0027] Typical embodiments embodying the features and advantages of the present invention will be specifically described in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0028] In the description of this application, the terms "first", "second", etc. are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the structure referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0029] Example 1 like Figure 1As shown in the figure, the quick-setting cementitious material mixing and construction equipment provided in this embodiment includes a mobile base 1, a tilting forced mixing host 2, a variable frequency speed control system 3, a water supply metering system, a tilting unloading mechanism 5, a guide chute 6, a material receiving construction trolley, and a tool integrated rack 8.

[0030] The mobile base 1 is a frame structure welded from high-strength square steel tubes with a wall thickness of 4mm. The overall dimensions are 1.4m long, 0.9m wide, and 0.3m high, and the total weight of the base is approximately 80kg.

[0031] To enable rapid movement and stable on-site installation of the equipment, four heavy-duty nylon casters 11 (each caster has a load capacity of 200kg and is equipped with a foot brake device (13)) are installed at the four corners of the base. Four spiral lifting support legs 15 (each leg has a load capacity of ≥500kg) are also installed at adjacent positions at the four corners. When the equipment is moved, the support legs 15 are in the retracted state and the wheels 11 are pushed on the ground. After arriving at the construction site, the wheel brake device 13 is locked for initial positioning. Then, the handle of the support leg 15 is rotated to lower it to the ground until the wheels 11 are slightly lifted off the ground (about 5~10mm). At this time, the equipment is completely supported by the four support legs 15, ensuring that the equipment is stable and does not shake during the mixing operation.

[0032] In addition, forklift holes 14 (100mm×50mm in diameter) are symmetrically provided on the front and rear sides of the base to facilitate loading, unloading and short-distance transportation; a storage platform 12 is provided on the right side of the base for placing pre-weighed bagged powder and quantitative containers 41 for easy on-site access.

[0033] The mixing unit 2 is a vertical shaft planetary forced mixer with a single batch mixing capacity of 0.3 m³. The mixing drum 21 has an inner diameter of 0.8 m and a height of 0.6 m, with the inner wall coated with a 0.3 mm thick non-stick polytetrafluoroethylene coating. The top of the mixing drum 21 is equipped with a cover plate, which includes an observation window and a powder feeding port. A mechanical seal or a double-lip skeleton oil seal is installed between the mixing shaft 22 and the mixing drum 21. The mixing shaft 22 is vertically positioned, and the mixing blades 23 are high-shear turbine blades. The gap between the blades and the inner wall of the mixing drum 21 is 5-8 mm, and the blade linear velocity is ≥4 m / s. There are two sets of blades, one set at the top and one at the bottom, with three blades in each set, arranged symmetrically at 120°. The blades are installed on the mixing shaft 22 using M12 quick-release wing bolts. The variable frequency motor 24 is a three-phase asynchronous variable frequency motor with a rated power of 7.5 kW, installed above the mixing drum 21. The variable frequency motor 24 is directly driven or driven by a 1:1 belt. The top of the mixing cylinder 21 is provided with a powder feeding port 25 with a diameter of 300mm and a water inlet 26 with a diameter of 50mm.

[0034] The variable frequency speed control system 3 includes a speed control control unit and a frequency converter. In this embodiment, the speed control control unit is an industrial-grade potentiometer-type manual speed control knob. The panel has 0~10 scale markings and corresponding frequency indicators (50~350 r / min), and is divided into "high speed" (250~350 r / min) and "low speed" (50~100 r / min) color blocks. The frequency converter is a general-purpose vector frequency converter with a power of 7.5kW, installed in a waterproof electrical control box on the side of the mobile base 1.

[0035] In this embodiment, the water metering system is a metering container 41 with a capacity scale, a 10L transparent polypropylene metering bucket, with clear scale lines (accuracy 0.1L) on the outer wall.

[0036] The tilting and unloading mechanism 5 includes a tilting bracket 51, a rotating shaft 52, and a worm gear reducer with a hand crank. The tilting bracket 51 consists of two sets of vertical steel frames, fixedly welded to the front left and rear left sides of the movable base 1. The rotating shaft 52 is horizontally positioned on the upper middle part of the left and right sides of the outer wall of the mixing cylinder 21. The worm gear reducer (speed ratio 1:60, self-locking type) is installed on the left tilting bracket 51, with its output end connected to the left end of the rotating shaft 52 and its input end connected to the hand crank.

[0037] The flow guide chute 6 is located at the edge of the discharge port of the mixing cylinder 21. In other embodiments, the flow guide chute 6 is a foldable structure, including a fixed section and a folding section. The folding section is connected to the fixed section by a hinge. When not in use, it is folded upward and stored on the outer wall of the mixing cylinder 21. When in use, it is unfolded downward. The end of the flow guide chute 6 is a flat duckbill-shaped outlet.

[0038] The material receiving and construction trolley has a flat, box-like body (71) welded from 2mm thick stainless steel plate, with external dimensions of 1.5m long, 0.7m wide, and 0.25m deep. The bottom of the body (71) is flat, and it has small casters (72) at each of the four corners. The inner wall of the body (71) is coated with a non-stick polytetrafluoroethylene (PTFE) coating. A retractable gate (73) made of 3mm thick stainless steel plate is located on one short side of the body (71), with guide grooves on both sides and a handle on the top.

[0039] The tool integrated bracket 8 is fixedly welded to the right side of the mobile base 1, including a scraper bracket, a vibrator bracket, and a spray bottle bracket. The brackets are equipped with spring clips, hooks, or clamps.

[0040] The cooling and temperature control system includes a water-cooled jacket installed on the outer wall of the mixing drum and a temperature sensor installed inside the mixing drum. The water-cooled jacket is connected to an external circulating cooling water source, and the temperature sensor is electrically connected to the controller to monitor the temperature of the slurry in real time during the mixing process and to trigger an alarm when the temperature exceeds 40°C.

[0041] The total weight of the equipment in this embodiment is approximately 280 kg, and the manufacturing cost is approximately 30,000 yuan.

[0042] Example 2 This embodiment, based on embodiment one, further integrates the following automatic modules: Automatic feeding system: including powder silo (capacity 0.5m³), screw conveyor and electronic weighing hopper (metering accuracy ±1%). The powder silo is a detachable conical silo, installed on the left side of the mobile base (1). The screw conveyor is set at an incline to transport the powder from the powder silo to the weighing hopper. After accurate weighing, it is automatically put into the mixing cylinder 21.

[0043] Automatic water supply metering system: includes a water tank (capacity 100L), water supply pipeline, electronic flow meter (metering accuracy ±1%) installed on the water supply pipeline, and solenoid valve, and the water supply is automatically controlled by a PLC controller.

[0044] PLC Control System: The speed control unit is a PLC programmable controller, which stores variable frequency speed control curves for high-speed stirring mode (300 r / min, 1.5 minutes) and low-speed hold-up mode (80 r / min), and can automatically switch stirring speeds according to a preset sequence. The PLC controller also connects to and controls the automatic feeding system, automatic water supply system, tilting drive device (using an electric push rod), and high-pressure automatic cleaning system.

[0045] High-pressure automatic cleaning system: including high-pressure water pump (pressure ≥5MPa), flushing pipeline and 360° rotating nozzle set on the top of the inner wall of the mixing drum 21. The flushing pressure of the high-pressure automatic cleaning system is ≥5 MPa. After each batch of material is unloaded, it is automatically started by the PLC controller to flush the inner wall of the mixing drum 21 and the mixing blades 23 in all directions.

[0046] The equipment in this embodiment weighs approximately 1.2 tons and has a manufacturing cost of approximately 150,000 to 200,000 yuan. It is suitable for large-scale continuous construction scenarios.

[0047] Example 3 like Figure 2 As shown, this implementation uses the control method from Example 1 for emergency repair work on a pothole (0.6m in diameter, 0.08m in depth, and approximately 0.025m³ in volume) on a highway. The specific implementation steps are as follows: S1: Equipment in place. Transport the equipment to the construction site by pickup truck, push it to a distance of about 1.5m from the pit, depress the brake device 13 on the four wheels 11, and remove the scraper, vibrator and spray bottle from the tool rack 8 for later use.

[0048] S2: Feeding and Water Addition. The pre-weighed, bagged dry-mix powder (15kg per bag) prepared in advance in the warehouse according to the mix proportion (phosphate cement: sand: retarder = 1:1.5:0.04) is added to the mixing drum 21 through the powder feeding port 25. 1.8L of water (water-cement ratio 0.12) is measured using a measuring container 41 and added to the mixing drum 21 through the water inlet 26.

[0049] S3: High-speed mixing. Rotate the speed control knob 31 to the high-speed setting and mix at 300 r / min for 1.5 minutes until the powder and water are fully mixed.

[0050] S4: Low-speed stirring. Rotate the speed control knob 31 to the low-speed position and continue stirring at a speed of 80 r / min. At this low speed, the hydration reaction rate of phosphate cement is significantly reduced, and the slurry remains in a workable flowable state for 15-25 minutes.

[0051] S5: Unloading. Push the receiving trolley below the guide chute 6 (gate 73 is closed), and the operator cranks the hand crank. Driven by the worm gear, the mixing drum 21 slowly tilts to the 90° unloading position. Under gravity, the mixture flows out from the large opening of the mixing drum 21, forming a flat flow through the duckbill-shaped outlet of the guide chute 6, and evenly flows into the receiving trolley. The unloading process takes approximately 15 seconds.

[0052] S6: Spreading and Forming. Push the material receiving trolley to the side of the pit, and place one side of the trolley's gate 73 close to the edge of the pit. The operator pulls the gate 73 upward with one hand while slowly lifting the side of the trolley 71 away from the gate 73 with the other hand. The slurry flows out evenly from the opening of the gate under the action of gravity and directly fills the pit.

[0053] S7: Smooth and Vibrate. Take the scraper from the tool rack 8, spray the retarder solution, and scrape it back and forth on the surface of the pit to smooth it; take the handheld plate vibrator and vibrate the repair surface to compact the grout.

[0054] S8: Cleaning. Immediately connect a water hose to the on-site water tap and rinse the inner wall of the mixing drum 21, the mixing blades 23, and the material receiving trolley for about 30 seconds.

[0055] Example 4 Applying the control method of Example 2, in the repair of multiple potholes on a continuous road section, the operator only needs to set the total batch quantity and mix ratio parameters for this construction on the PLC touch screen. The equipment automatically completes the mixing, unloading, and cleaning processes, while the paving and placement into the formwork are completed manually with the assistance of a material receiving trolley. S1: Equipment in place. The equipment is transported to the construction site by trailer, pushed to the construction area, and the "Start" button is pressed.

[0056] S2: Automatic feeding and water addition. The PLC controller issues a command, and the screw conveyor transports the powder from the powder silo to the electronic weighing hopper. After accurate weighing, the powder is automatically added to the mixing drum 21. At the same time, the solenoid valve opens, and the electronic flow meter accurately measures the amount of water and then injects it into the mixing drum 21 through the water inlet 26.

[0057] S3-S4: Automatic frequency conversion stirring. The PLC controller automatically executes according to the built-in curve: first, it stirs at a high speed of 300 r / min for 1.5 minutes, and then automatically switches to low speed stirring at 80 r / min to keep the mixture alive.

[0058] S5: Automatic unloading. After the operator places the material receiving trolley under the guide chute 6, presses the "unload" button, and the electric push rod automatically rotates the mixing cylinder 21 to the 90° unloading position. After unloading is completed, it automatically resets.

[0059] S6: Manual spreading. Same as step S6 in Example 1.

[0060] S7: Automatic cleaning. After each batch of material is unloaded, the PLC controller automatically starts the high-pressure water pump. The high-pressure water sprays through the nozzles to thoroughly clean the inner wall of the mixing drum 21 and the mixing blades 23. The cleaning process stops automatically after 30 seconds.

[0061] Industrial applicability The rapid-setting cementitious material mixing and construction equipment and its control method provided by this invention have broad industrial application prospects: Emergency road repair: Phosphate cement can be used for rapid repair of highways, urban roads, airport runways, and other projects. Phosphate cement has excellent properties such as fast setting speed, high early strength, and good bonding performance. When used with the on-site mixing and construction equipment of this invention, it can be applied immediately after on-site mixing.

[0062] Rapid construction of military engineering projects: It can be used for the construction of military facilities with extremely high requirements for construction speed, such as national defense projects and field airports.

[0063] Emergency repair of municipal pipelines: It can be used for the rapid repair of small structures such as underground pipeline inspection wells and valve wells.

[0064] Bridge expansion joint repair: Quick-setting materials can be used to fill and repair bridge expansion joints.

[0065] Mine roadway support: Magnesium phosphate cement grouting material can harden quickly and generate high strength internally. When used with the equipment of this invention, it can be used for rapid support and reinforcement of mine roadways.

[0066] Winter emergency construction: Phosphate cement has excellent low-temperature resistance, and when used with the equipment of this invention, it can be used for rapid repair construction in low-temperature environments.

[0067] This invention provides both manual and automatic control implementations. The manual implementation uses manual material feeding, a metered container for water addition, and manual speed adjustment. The equipment is compact, weighs no more than 300 kg, and can be transported by a regular pickup truck. Its manufacturing cost is significantly lower than conventional mobile mixing equipment, making it particularly suitable for emergency repairs involving small volumes and multiple locations. The automatic control implementation, while retaining the same core structure, integrates an automatic feeding system, a PLC controller, solenoid valves, and a high-pressure cleaning device, making it suitable for large-scale continuous construction operations. Both implementations share the same tipping and unloading mechanism and material receiving and paving mechanism, demonstrating the invention's excellent technical uniformity and adaptability to various scenarios.

[0068] Example 5 like Figure 3 and Figure 4 As shown, the material receiving trolley uses an automatic valve to replace the removable gate. The automatic valve includes a drive motor 91, a lead screw 92, a slider 93, a connecting frame 94, a push plate 95, and a movable door 96. A guide rail is provided on one side of the trolley body 71. The drive motor 91 is mounted on the trolley body 71 shell, the lead screw 92 is installed in the guide rail, and the slider 93 is screwed onto the lead screw 92. The drive motor 91 can drive the lead screw 92 to rotate, so that the slider 93 slides in the guide rail. The connecting frame 94 is fixedly connected to the slider 93, and the push plate 95 and the movable door 96 are fixedly connected to both ends of the connecting frame 94. In the initial state, the movable door 96 closes the opening of the trolley body 71, and the push plate 95 is located on the opposite side of the opening inside the trolley body. When spreading and pouring into the mold, the push plate 95 moves towards the opening side, and the movable door 96 simultaneously disengages from the opening, thereby opening the trolley body 71. A ramp is provided at the lower end of the opening of the trolley body 71 to guide the material.

[0069] A composite sealing strip can be installed directly between the movable door 93 and the opening to ensure a tight seal; the edge of the push plate 95 is equipped with an elastic scraper lip made of urethane, rubber or PTFE.

[0070] The above structure replaces the tilting of the entire vehicle body 73, making operation easier; the opening size can be controlled by adjusting the position of the slider 93, making the opening size adjustable; and the material can be scraped by moving the push plate 95, ensuring that the internal material is completely discharged as much as possible.

[0071] Example 6 To verify the effect of different stirring speeds on the rapid dispersion of quick-setting cementitious materials, the same batch of magnesium phosphate cement-based quick-setting cementitious materials were used as test materials. Under the same feed amount, the same water-to-material ratio, the same stirring blade structure, and the same stirring time, only the stirring shaft speed was changed for comparative testing.

[0072] Each experimental group was stirred at speeds of 30 r / min, 100 r / min, 150 r / min, 200 r / min, 250 r / min, 300 r / min, 350 r / min, and 400 r / min, respectively, for a total stirring time of 1.5 min. After stirring, the size of agglomerates and the degree of uniform dispersion in the mixture were evaluated by sieving and image analysis, while the temperature change of the slurry during the stirring process was recorded.

[0073] The experimental results are shown in the table below.

[0074] The above test results show that when the stirring speed is lower than 250 r / min, large powder agglomerates are still easily formed in the rapid-setting cementitious material within the same 1.5 min stirring time, and the degree of uniform dispersion is significantly reduced. This indicates that it is difficult to complete the full dispersion of the rapid-setting cementitious material in a short time using ordinary low-speed stirring equipment.

[0075] When the stirring speed reaches 240-260 r / min, the dispersion rate has increased to about 95%; when it is further increased to above 300 r / min, the increase in dispersion rate slows down, indicating that the material system can achieve sufficient dispersion within this speed range; when the speed is increased to 400 r / min, the temperature rise further increases to about 8.8℃, while the improvement in dispersion rate is extremely limited at this point (only from 97.8% to 98.0%). Therefore, from an engineering practice perspective, excessively high speeds are unnecessary.

[0076] Therefore, the present invention sets the high-speed stirring speed to 250-350 r / min, which ensures that the fast-setting cementitious material can be fully dispersed in a short time, while avoiding unnecessary temperature rise caused by excessive speed, and provides a suitable initial state for subsequent low-speed retention.

[0077] Example 7 In Example 6, after rapid dispersion by stirring at 300 r / min for 1.5 min, the mixture was continuously stirred at 0 r / min, 30 r / min, 50 r / min, 80 r / min, 100 r / min and 150 r / min respectively. The time when the fluidity of the mixture decreased significantly to the point that it did not meet the requirements for on-site paving was recorded, and the fluidity retention rate after 30 min was calculated.

[0078] The test results are as follows: The above test results show that when high-speed mixing is stopped immediately, the mixture loses its fluidity quickly when left to stand. The mixture can achieve significantly better retention than static mixing in the range of 60 to 100 r / min, with better overall performance around 80 r / min, but the difference is not significant in the range of 70 to 90 r / min.

[0079] Within the range of 50 to 100 r / min, the working time varies to some extent at different speeds, but it is significantly better than static holding (0 r / min) and excessively high speed (150 r / min).

[0080] This invention employs a two-stage mixing mode that combines high-speed mixing with low-speed retention. The high-speed stage is mainly used to quickly break up powder agglomerates and form a uniform mixture, while the low-speed stage is used to prevent the mixture from losing its fluidity quickly due to standing while waiting for unloading, transportation, and construction.

[0081] Example 8 To further verify the technical effectiveness of the two-stage stirring control method of the present invention, the following control group was set up: Control group 1 was stirred continuously at 30 r / min for 3 min; Control group 2 was stirred at 300 r / min for 1.5 min and then stopped. Control group 3 was stirred continuously at 300 r / min; The experimental group used the high-speed stirring at 300 r / min for 1.5 min according to the present invention, and then switched to the low-speed survival mode at 80 r / min.

[0082] Tests were conducted under the same material ratio and environmental conditions to determine the construction time, 2-hour compressive strength, and temperature rise during the mixing process.

[0083] The test results are as follows: The results above show that while simply increasing the stirring speed can improve the dispersion effect of the material, it will cause a large temperature rise under high-speed continuous stirring and cannot effectively extend the workable time of the material; while stopping stirring directly after high-speed stirring can easily cause the material to lose its fluidity quickly while waiting for construction.

[0084] The 2-hour compressive strength of the experimental group was slightly lower than that of the control group 2, but still much higher than that of the control group 1 (17.8 MPa), indicating that while the low-speed survival mode significantly extended the construction time, its impact on early strength was within the acceptable range for the project.

[0085] This invention achieves rapid dispersion by first employing high-speed stirring at 300 r / min, then switching to low-speed stirring at 80 r / min to maintain fluidity, thus seamlessly connecting the two processes of rapid dispersion and fluidity maintenance. Without significantly sacrificing early strength, this substantially extends the workable time of the mixture, providing ample time for subsequent unloading, transfer, and placement into formwork.

[0086] Therefore, the technical effect of this invention does not come from simply increasing the stirring speed, but from the synergistic cooperation between high-speed rapid dispersion, low-speed dynamic retention, and subsequent rapid unloading and paving.

[0087] Example 9 To verify the impact of the overall tilting unloading structure on the on-site construction efficiency of fast-setting cementitious materials, unloading was carried out using a 150mm bottom butterfly valve, a 250mm large-diameter valve, and the overall tilting method with a large top opening as described in this invention, under the same mixing conditions.

[0088] The test results are as follows: The residual rate after unloading by the top tilting valve is about 1.5% to 3.5% (average of about 2.2% in multiple tests), which is significantly better than bottom butterfly valves and large-diameter valves.

[0089] As can be seen from the above results, the present invention uses the overall tilting of the mixing cylinder and the large-diameter opening at the top of the cylinder for unloading, which eliminates the need for the mixed material to pass through the narrow valve body. This can significantly reduce the residue of fast-setting cementitious materials in the valve and sealing parts, and shorten the unloading time.

[0090] Especially for fast-setting cementitious materials with short setting times, the unloading time itself will occupy the effective construction window of the material. Therefore, the overall tilting unloading is not simply a change in the unloading direction, but is coordinated with the aforementioned high-speed rapid dispersion and low-speed retention process to further reduce the time loss between the completion of mixing and the entry of the material into the construction position.

[0091] Example 10 Further comparison was made of the time required from the completion of mixing to the completion of pouring into the mold using the traditional manual shovel method and the material receiving and construction trolley method of this invention.

[0092] Traditionally, after the material is unloaded from the mixer, it is transported and spread manually using shovels. In this invention, the mixing drum is tilted as a whole, and after passing through the guide chute into the material receiving construction trolley, the material receiving construction trolley moves directly to the construction position and opens the gate to spread the material.

[0093] Multiple tests were conducted under the same construction distance (approximately 2–5 m) and single batch material volume (approximately 0.025–0.05 m³). The material receiving trolley method of this invention requires approximately 35–80 s (affected by ground flatness and operator proficiency), which is significantly shorter than the traditional manual shoveling method (240–450 s).

[0094] As can be seen, by coordinating the mixing equipment, the rapid unloading structure, and the material receiving trolley, the present invention significantly reduces the intermediate transfer links of the fast-setting cementitious material from the completion of mixing to its final entry into the construction site, thereby improving the utilization rate of the limited construction time window.

[0095] Based on the above test results, this invention is not a simple combination of existing mixing equipment, unloading equipment, and transportation vehicles. Instead, it focuses on the material characteristics of fast-setting cementitious materials, such as rapid setting speed, concentrated heat release, and short effective construction time, and matches the time of the entire process of mixing, holding, unloading, and paving: First, high-speed mixing at 250-350 r / min is used to quickly disperse the powder in a short time; then, low-speed holding at 50-100 r / min is used to reduce the temperature rise caused by continuous high-speed mixing, while keeping the mixture in a flowable state suitable for construction; after the material receiving trolley arrives, the material is quickly unloaded by tilting the entire mixing cylinder and opening the large diameter opening at the top; finally, the material is directly transferred using the material receiving trolley and quickly paved into the formwork using a removable gate.

[0096] Therefore, the various technical links have a clear functional connection, which together reduce the time loss in the process of adding water and mixing the quick-setting cementitious material to the final pouring into the mold. This matches the equipment operating parameters with the material's setting characteristics, and compared to technical solutions that only increase the speed of ordinary mixing equipment or add moving mechanisms, it can achieve better on-site rapid construction results. The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A mixing and construction equipment for fast-setting cementitious materials, characterized in that, include: A mobile base (1) is provided with wheels (11) at the bottom of the mobile base (1) for moving and positioning the equipment on the construction site; The flip-type forced mixing host (2) is installed on the mobile base (1) and includes a mixing cylinder (21), a mixing shaft (22) and a mixing blade (23) set in the mixing cylinder (21), and a variable frequency motor (24) for driving the mixing shaft (22) to rotate; the top of the mixing cylinder (21) is provided with a powder feeding port (25) and a water inlet (26); the discharge port of the mixing cylinder (21) is the opening at the top of the cylinder; The variable frequency speed control system (3) includes a speed control control unit and a frequency converter. The speed control control unit is electrically connected to the frequency converter, and the frequency converter is electrically connected to the variable frequency motor (24). The variable frequency speed control system (3) is configured to adjust the speed of the stirring shaft (22) to a high-speed stirring gear of 250-350 r / min and a low-speed holding gear of 50-100 r / min. A water metering system is used to add metered mixing water into the mixing drum (21); The tilting and unloading mechanism (5) includes a tilting bracket (51) fixedly installed on the mobile base (1), a rotating shaft (52) set on the outer wall of the mixing cylinder (21), and a tilting drive device for driving the rotating shaft (52) to rotate. The mixing cylinder (21) is rotatably installed on the tilting bracket (51) via the rotating shaft (52). Under the action of the tilting drive device, the mixing cylinder (21) can switch between the vertical mixing position and the tilting unloading position around the rotating shaft (52). When unloading, the mixing cylinder (21) tilts as a whole, and the material is directly poured out through the top opening of the cylinder. The guide chute (6) is set at the edge of the discharge port of the mixing cylinder (21) to guide the mixed material to the receiving construction trolley when the material is tilted for unloading. The material receiving construction trolley includes a vehicle body (71), a walking wheel (72) set at the bottom of the vehicle body (71), and a removable gate (73) set on one side of the vehicle body (71). The vehicle body (71) receives the mixed material unloaded from the guide chute (6) and moves to the construction point. The mixed material is spread into the formwork by removing the gate (73) and tilting the vehicle body (71).

2. The quick-setting cementitious material mixing and construction equipment according to claim 1, characterized in that: The stirring blade (23) is a high-shear turbine blade or a serrated disc blade. The gap between the blade and the inner wall of the stirring cylinder (21) is 5-8 mm, and the blade linear velocity is ≥4 m / s.

3. The quick-setting cementitious material mixing and construction equipment according to claim 1, characterized in that: The tilting drive device is a manual tilting drive assembly or an automatic tilting drive assembly; The manual tilting drive assembly is a worm gear reducer with a hand crank. The worm gear reducer has a self-locking function. The stirring cylinder (21) can be switched between the vertical position and the inclined position and stopped at any inclined angle by manual cranking. The automatic tilting drive component is an electric push rod or a hydraulic cylinder, which is controlled by a controller to realize the automatic tilting and resetting of the stirring cylinder (21).

4. The mixing and construction equipment for rapid-setting cementitious materials according to claim 1, characterized in that: It also includes a cooling and temperature control system, which includes a water-cooled jacket installed on the outer wall of the mixing drum (21) and a temperature sensor installed inside the mixing drum (21). The water-cooled jacket is connected to an external circulating cooling water source, and the temperature sensor is electrically connected to the controller to monitor the temperature of the slurry in real time during the mixing process and to alarm when the temperature exceeds the set value.

5. The mixing and construction equipment for rapid-setting cementitious materials according to claim 1, characterized in that: The inner wall of the material receiving construction trolley (71) is provided with a non-stick coating, which is a polytetrafluoroethylene coating or a ceramic coating; the depth of the trolley (71) does not exceed 0.3 meters, and the bottom is flat; the two sides of the removable gate (73) are provided with guide grooves (75), and the gate (73) slides up and down along the guide grooves (75) to open and close, and the top of the gate (73) is provided with a handle; The inner wall of the stirring cylinder (21) is provided with a non-stick coating, which is a polytetrafluoroethylene coating; the stirring blade (23) is installed on the stirring shaft (22) through a quick-release connector.

6. The mixing and construction equipment for rapid-setting cementitious materials according to claim 1, characterized in that: The mobile base (1) is provided with a tool integrated rack (8), which includes at least one scraper rack, a vibrator rack and a spray bottle rack; the mobile base (1) is also provided with a storage platform (12) and a forklift hole (14); the traveling wheels (11) are universal wheels with braking devices (13); the four corners of the mobile base (1) are also provided with adjustable support legs (15), which are spiral lifting type or hydraulic jack type structures.

7. The mixing and construction equipment for rapid-setting cementitious materials according to claim 1, characterized in that: The water supply metering system uses a quantitative container (41) with a capacity scale or an automatic water supply metering component; The metering container (41) is used for manually measuring and adding mixing water; Automatic water metering components include a water tank, water supply pipeline, a flow meter or electronic scale installed on the water supply pipeline, and a solenoid valve, with the water supply volume automatically controlled by a controller.

8. The mixing and construction equipment for rapid-setting cementitious materials according to claim 1, characterized in that: It also includes an automatic feeding system and a high-pressure automatic cleaning system. The automatic feeding system includes a powder silo, a screw conveyor and a weighing device, which are used to automatically feed the metered powder into the mixing drum (21). The high-pressure automatic cleaning system includes a high-pressure water pump, a flushing pipeline and a nozzle installed on the inner wall of the mixing drum (21). The flushing pressure of the high-pressure automatic cleaning system is ≥5 MPa, and it is used to flush the inner wall of the mixing drum (21) and the mixing blades (23) after each batch of material is unloaded.

9. The mixing and construction equipment for rapid-setting cementitious materials according to claim 1, characterized in that: The top of the mixing cylinder (21) is provided with a cover plate, and the cover plate is provided with an observation window and a powder feeding port; a mechanical seal or a double-lip skeleton oil seal is provided between the mixing shaft (22) and the mixing cylinder (21).

10. A method for controlling the mixing and construction of rapid-setting cementitious materials using the equipment described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Move the equipment to the construction site and position it; S2: Add the pre-mixed quick-setting cementitious dry powder into the mixing drum (21) and add a certain amount of mixing water; S3: The material is stirred and dispersed at high speed in a high-speed stirring mode of 250-350 r / min by the speed control unit for 1-2 minutes. S4: By using the speed control unit, switch the mixing speed to a low-speed maintenance mode of 50-100 r / min to perform low-speed maintenance mixing and keep the mixture in a workable state. S5: Place the material receiving trolley under the guide chute (6), and tilt the mixing cylinder (21) by using the tilting drive device to unload the mixed material into the material receiving trolley through the guide chute (6); S6: Push the material receiving trolley to the construction point, remove the removable gate (73) on the side wall of the trolley, and tilt the trolley body (71) at the same time so that the mixed material flows out under gravity and is spread into the mold. S7: After the construction is completed, the mixing drum (21) and the material receiving trolley are cleaned.

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