A concrete spread measuring device

Abstract

The utility model discloses a kind of concrete expansion degree measuring devices, it includes test platform, vertically rotatable steel pipe is equipped on test platform, the lower end of steel pipe is connected with the first motor in test platform by transmission mechanism, steel pipe can be driven to rotate by the first motor, second motor and lifting mechanism driven by second motor are equipped in steel pipe, lifting mechanism is equipped with the middle cross bar that extends along the radial of steel pipe, the end of middle cross bar is equipped with the grip hoop for fixing slump cylinder, middle cross bar and grip hoop can be lifted by lifting mechanism, the upper end of steel pipe is equipped with the upper cross bar that extends along the radial of steel pipe, the end of upper cross bar is equipped with the picture acquisition device for collecting test platform table surface image, middle cross bar and upper cross bar have horizontal angle, reference circle used as reference in visual identification is equipped on the table surface of test platform with concentricity.The utility model improves the efficiency of test, and improves the accuracy of test.

Description

Technical Field

[0001] This utility model relates to the field of concrete material testing technology, specifically a concrete spreadability measuring device. Background Technology

[0002] Concrete spread refers to the average diameter of freshly mixed concrete as it flows freely under its own weight. It indirectly reflects the concrete's ability to flow during construction and is commonly used to assess its workability. Generally, the design and construction of self-compacting concrete and high-strength pumped concrete impose requirements on workability. According to GB / T50080-2016, the spread of self-compacting concrete should not be less than 600 mm, and the spread of high-strength pumped concrete should not be less than 500 mm. If the concrete's fluidity does not meet the requirements, it will not only affect the pumping process during construction but also the quality of the hardened concrete. Therefore, concrete spread is one of the key aspects of concrete quality control.

[0003] Currently, traditional methods for testing the spreadability of concrete mainly involve manual operation: Under environmental conditions of 20±5℃ and relative humidity not less than 50%, a prepared concrete sample is placed into a standard slump cone (a truncated conical cone with an upper diameter of 100mm, a lower diameter of 200mm, and a height of 300mm). After removing concrete from the bottom plate of the cone, the slump cone should be lifted vertically and smoothly, with the lifting process controlled within 3-7 seconds. After lifting the slump cone, when the concrete mixture stops spreading or the spreading time has reached 50 seconds, a steel ruler with a range of not less than 1000mm and a graduation value not greater than 1mm should be used to measure the maximum diameter of the spread surface of the concrete mixture and the diameter perpendicular to the maximum diameter. When the difference between the two diameters is less than 50mm, their arithmetic mean should be taken as the spreadability test result. When the difference between the two diameters is not less than 50mm, a new sample should be taken and measured again. The entire process of the spread test, from the start of loading to the measurement of the concrete spread value, should be carried out continuously and should be completed within 4 minutes.

[0004] The above-mentioned traditional methods for testing the flowability of concrete have the following problems:

[0005] (1) Large error in manual measurement: During the steel ruler measurement process, the operator relies on experience to find the maximum diameter and vertical diameter by visual observation, which is not accurate enough. Vertical measurement is more susceptible to the influence of angle deviation and reading error.

[0006] (2) Inefficient: A single test requires 2-3 people to cooperate and takes 5-10 minutes. In particular, the maximum diameter is selected by visual inspection and experience. It usually requires multiple attempts to determine the maximum diameter. Then, the vertical diameter is measured using this maximum diameter as a reference line, which is cumbersome.

[0007] (3) Insufficient objectivity of data: The operator relies on manual observation to find the maximum diameter, which is too subjective. The manual judgment of the extension endpoint (such as "extension stops") is also subjective and may lead to deviation in the results.

[0008] (4) Inaccurate measurement of expansion time: Time parameters such as T50 need to be timed manually, which may result in small time errors and make it difficult to capture the dynamic changes in the expansion process of concrete mixture (such as expansion rate curve). Utility Model Content

[0009] The purpose of this invention is to provide a device for measuring the spread of concrete.

[0010] The objective of this utility model is achieved through the following technical solution:

[0011] A concrete slump measuring device, characterized in that: it includes a testing platform, on which a rotatable vertical steel pipe is provided. The lower end of the steel pipe is connected to a first motor inside the testing platform through a transmission mechanism, which drives the steel pipe to rotate. A second motor and a lifting mechanism driven by the second motor are provided inside the steel pipe. A middle crossbar extending radially along the steel pipe is provided on the lifting mechanism. The end of the middle crossbar is provided with a clamp for fixing a slump cone. The middle crossbar and the clamp can be lifted and lowered by the lifting mechanism. An upper crossbar extending radially along the steel pipe is provided at the upper end of the steel pipe. The end of the upper crossbar is provided with an image acquisition device for acquiring images of the test platform surface. The middle crossbar and the upper crossbar have a horizontal angle. Concentric reference circles for visual recognition are provided on the test platform surface.

[0012] A further technical solution of this utility model is: a level is provided on the side of the test platform.

[0013] A further technical solution of this utility model is as follows: the second motor is located inside the bottom of the steel pipe, the lifting mechanism includes a nut that is slidably located inside the steel pipe and a vertically arranged screw rod, the nut is threadedly connected to the screw rod, the lower end of the screw rod is connected to the second motor, and the screw rod is driven to rotate by the second motor, the steel pipe wall is provided with a vertically extending opening, and the middle crossbar passes through the opening and is fixedly connected to the nut.

[0014] A further technical solution of this utility model is as follows: the transmission mechanism includes a driven gear located at the lower end of the steel pipe and a driving gear located on the first motor, wherein the driven gear meshes with the driving gear.

[0015] A further technical solution of this utility model is: the reference circle is a circular engraving on the test platform surface.

[0016] A further technical solution of this utility model is: the surface of the test platform, except for the reference circle, is coated with a reflective coating.

[0017] A further technical solution of this utility model is: the image acquisition device includes a downward-facing camera, a downward-facing fill light, and a downward-facing laser sight.

[0018] A further technical solution of this utility model is: the bottom of the test platform is equipped with height-adjustable casters.

[0019] A further technical solution of this utility model is: a support member is provided around the upper periphery of the slump cylinder, and a protruding protrusion is provided on the support member for supporting the clamp.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention eliminates the need for manual operation in measuring the slump of concrete. The lifting mechanism for the slump cone during testing allows for better control of lifting speed and stability. After lifting, the image acquisition device is rotated above the testing platform via a rotating steel pipe to photograph the concrete being tested. The captured images can then be processed in a separate image processing system to obtain the diameter, eliminating the need for manual measurement. Therefore, this invention improves both testing efficiency and accuracy. Attached Figure Description

[0022] Figure 1 This is a side view of the expansion measurement device according to an embodiment of the present invention.

[0023] Figure 2 This is a front view structural diagram of the expansion measurement device according to an embodiment of the present utility model;

[0024] Figure 3 This is a top view of the expansion measurement device according to an embodiment of the present invention;

[0025] Figure 4 This is a cross-sectional view of the expansion measurement device according to an embodiment of the present invention;

[0026] Figure 5 This is a structural schematic diagram of the steel pipe and its components according to an embodiment of the present utility model;

[0027] Figure 6 This is a top view of the steel pipe and its components according to an embodiment of the present utility model;

[0028] Figure 7 This is a schematic diagram of the image acquisition device according to an embodiment of the present utility model;

[0029] Figure 8 This is a schematic diagram of the slump cone and clamp according to an embodiment of the present utility model;

[0030] Figure 9 This is a schematic diagram of the slump measuring device according to an embodiment of the present invention, when the slump cylinder is placed in the middle of the test platform during the slump test.

[0031] Figure 10 This is a schematic diagram of the slump measuring device according to an embodiment of the present invention, when the slump cylinder is lifted during the slump test.

[0032] Figure 11 This is a schematic diagram of the structure of the expansion measurement device of this utility model during the expansion test when the image acquisition device takes pictures.

[0033] Meaning of the labels in the attached diagram:

[0034] 1-Testing platform; 2-Steel pipe; 2.1-Opening; 3-Image acquisition device; 3.1-Touch screen; 3.2-Supplemental light; 3.3-Camera; 3.4-Laser sight; 4-Central crossbar; 5-Cast; 5.1-Rotating adjustment head; 6-Slump cylinder; 6.1-Support component; 6.2-Protrusion; 7-Clamping hoop; 7.1-First semicircular ring; 7.2-Second semicircular ring; 7.3-Pin shaft; 7.4-Snap fastener or bolt; 8-Lifting mechanism; 8.1-Bearing; 8.2-Screw; 8.3-Steel ball; 8.4-Nut; 9-Reference circle; 10-Bubble level; 11-Concrete sample; 12-Shooting boundary; 13-Upper crossbar; 14-Transmission mechanism; 14.1-Driving gear; 14.2-Driven gear; a1-First motor; a2-Second motor. Detailed Implementation

[0035] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments, so that those skilled in the art can better understand and implement the design scheme of this utility model.

[0036] like Figures 1 to 8 The concrete spread measurement device shown in this embodiment includes a test platform 1, a steel pipe 2, a transmission mechanism 14, a first motor a1, a second motor a2, a lifting mechanism 8, a middle crossbar 4, a clamp 7, an upper crossbar 13, and an image acquisition device 3.

[0037] The test platform 1 in this embodiment consists of a stainless steel frame and a steel plate fixed to the stainless steel frame. The steel plate serves as the tabletop, with dimensions of 1500mm x 1500mm, a thickness of 3mm, and a maximum deflection of no more than 3mm. Bubble levels 10 are installed at the center of each of the four sides of the test platform 1, allowing for convenient observation of the tabletop's levelness. Casters 5 are installed at each of the four corners of the test platform 1. In this embodiment, the casters 5 are conventional height-adjustable casters, each equipped with a rotating adjustment head 5.1 for height adjustment. Since they are conventional casters, their structure will not be described in detail here.

[0038] In this embodiment, seven concentric reference circles 9 of different sizes are provided on the surface of the test platform 1 for use in visual recognition. The reference circles 9 are circular engravings on the surface of the platform, and the radii between adjacent reference circles 9 differ by 10 cm. The center of the reference circles 9 is basically aligned with the geometric center of the test platform 1. The remaining surfaces of the test platform 1, except for the reference circles 9, are coated with a reflective coating.

[0039] The steel pipe 2 is vertically installed, with its lower end rotatable via a conventional bearing, and is located on one side of the test platform 1. The lower end of the steel pipe 2 is connected to a first motor a1 within the test platform 1 via a transmission mechanism 14, which drives the steel pipe 2 to rotate. The specific structure is as follows: Figure 4 As shown, the transmission mechanism 14 in this embodiment includes a driven gear 14.2 located at the lower end of the steel pipe 2 and a driving gear 14.1 mounted on the first motor a1. The driven gear 14.2 meshes with the driving gear 14.1. In use, the first motor a1 drives the driving gear 14.1 to rotate, which in turn drives the driven gear 14.2 and the steel pipe 2 to rotate. In this embodiment, the steel pipe 2 is a stainless steel pipe with a length of 1500 mm and a diameter of 150 mm.

[0040] Both the second motor a2 and the lifting mechanism 8 are located inside the steel pipe 2, with the second motor a2 located at the bottom of the steel pipe 2. In this embodiment, the lifting mechanism 8 includes a nut 8.4 slidably disposed within the steel pipe 2 and a vertically arranged screw 8.2, with the nut 8.4 threadedly connected to the screw 8.2. The sliding connection structure between the nut 8.4 and the steel pipe 2 is specifically as follows: multiple sets of steel balls are provided on the outer wall of the nut 8.4, each set including multiple vertically arranged steel balls 8.3. A portion of the steel balls 8.3 is embedded in the outer wall of the nut 8.4, and the steel balls 8.3 can rotate freely. An axially extending groove is provided on the inner wall of the steel pipe 2 corresponding to each set of steel balls 8.3, with a portion of the steel balls 8.3 located in the groove, thus restricting the movement of the steel balls within the groove.

[0041] The upper end of the screw 8.2 is connected to the steel pipe 2 via a bearing 8.1, and the lower end of the screw 8.2 is connected to a second motor a2. The second motor a2 drives the screw 8.2 to rotate, and the rotation of the screw 8.2 drives the nut 8.4 to move up and down. The steel pipe 2 has a vertically extending opening 2.1 on its wall, and the position of the opening 2.1 corresponds to the position of the nut 8.4.

[0042] One end of the central crossbar 4 passes through the opening 2.1 and is fixedly connected to the nut 8.4, allowing it to move up and down with the nut 8.4. A clamp 7 is located at the other end of the central crossbar 4 and is used to fix the slump cone 6. The clamp 7 adopts a conventional structure, specifically as follows: Figure 8 As shown, the clamp 7 includes a first semicircular ring 7.1 and a second semicircular ring 7.2. The first semicircular ring 7.1 is fixed to the central crossbar 4. One end of the second semicircular ring 7.2 is rotatably connected to one end of the first semicircular ring 7.1 via a pin 7.3, and the other end of the second semicircular ring 7.2 is connected to the other end of the first semicircular ring 7.1 via a buckle or a bolt 7.4. After the first semicircular ring 7.1 and the second semicircular ring 7.2 are fully closed, the inner diameter formed is 105mm.

[0043] In this embodiment, the slump cylinder 6 has an upper port diameter of 100mm, a lower port diameter of 200mm, and a height of 300mm. Four support members 6.1 are provided around the upper end of the slump cylinder 6. The support members 6.1 are provided with protruding protrusions 6.2 on the outside for supporting the clamp.

[0044] The upper horizontal bar 13 is horizontally fixed to the upper end of the steel pipe 2, and the image acquisition device 3 is located at the end of the upper horizontal bar 13. The image acquisition device 3 is used to acquire images of the test platform 1. Figure 6 As shown, in this embodiment, the middle crossbar 4 and the upper crossbar 13 have a 90° horizontal angle. During use, the steel pipe 2 is rotated by the first motor a1, which allows the image acquisition device 3 to be positioned above the test platform 1, or the slump cylinder 6 to be positioned above the test platform 1. When the image acquisition device 3 is positioned above the test platform 1, the image acquisition device 3 is vertically aligned with the center of the reference circle 9. When the slump cylinder 6 is positioned above the test platform 1, the slump cylinder 6 is vertically aligned with the center of the reference circle 9.

[0045] In this embodiment, the image acquisition device 3 is equipped with a downward-facing camera 3.3, a downward-facing fill light 3.2, and a downward-facing laser sight 3.4 at the lower part, and a touch screen 3.1 at the upper part.

[0046] The specific testing process of the concrete spreadability measuring device in this embodiment is as follows:

[0047] Step 1: Observe the bubble level 10 of the test platform 1, and adjust the height of the casters 5 to keep the test platform 1 level.

[0048] Step 2: As Figure 9 As shown, wet the slump cone 6 and the test platform 1 with a wet towel, then place the slump cone 6 in the center of the test platform 1, and fasten the upper end of the slump cone 6 with a clamp 7. According to the national standard specifications, place the prepared concrete sample 11 into the slump cone 6 in 3 layers, and perform the tamping and smoothing steps according to the specifications.

[0049] Step 3: Begin the scalability test. For example... Figure 10 As shown, the second motor a2 drives the lifting mechanism 8, which in turn raises the slump cylinder 6 to a specific height within 3-7 seconds. Then, the first motor a1 drives the steel pipe 2 to rotate 90° counterclockwise, causing the slump cylinder 6 to rotate and translate to the outer edge of the test platform 1. Meanwhile, the image acquisition device 3 rotates and translates to be directly above the test platform 1. At this point, the laser sight 3.4 should be aimed at the exact center of the test platform 1, the supplementary light 3.2 is turned on, and the image acquisition device 3 begins to acquire image information of the concrete sample 11 during the change in its expansion at a fixed exposure time. (As shown...) Figure 11 As shown in the figure, the concrete sample 11 has been expanded, and the shooting boundary 12 of the camera 3.3 is shown in the figure.

[0050] The image information collected during the above test will be transmitted to the image processing system for processing. Circle 9 serves as a reference in the image processing process. The image processing system will obtain the boundary and maximum diameter of concrete sample 11. Then, the average changes in the maximum diameter and the perpendicular diameter will be compared with time to generate an expansion rate curve. The process will stop when concrete sample 11 stops spreading or the spreading duration reaches 50 seconds. The maximum diameter and the diameter perpendicular to it will be judged. If the difference between the two diameters is less than 50 mm, the test is valid, and the arithmetic mean of the two diameters is taken as the final result, and the test is complete. If the difference between the two diameters is not less than 50 mm, the test is invalid, and a new sample should be taken for measurement.

[0051] The image processing system described above is implemented using conventional image processing methods and is not the content that needs to be protected by this utility model. The image processing system can be set in an external computer or in the image acquisition device of the concrete spread measurement device in this embodiment.

[0052] In practical cases, the above testing process can be used to measure the spread of both self-compacting concrete and pumped high-strength concrete.

[0053] The above embodiments of this utility model are not intended to limit the scope of protection of this utility model. The implementation of this utility model is not limited thereto. All other modifications, substitutions or alterations made to the above structure of this utility model based on the above content of this utility model and in accordance with the common technical knowledge and conventional means in the field, without departing from the basic technical idea of ​​this utility model, shall fall within the scope of protection of this utility model.

Claims

1. A concrete spreadability measuring device, characterized in that: The system includes a testing platform with a rotatable vertical steel pipe. The lower end of the steel pipe is connected to a first motor within the testing platform via a transmission mechanism, which drives the steel pipe to rotate. Inside the steel pipe are a second motor and a lifting mechanism driven by the second motor. The lifting mechanism has a central crossbar extending radially from the steel pipe, and the end of the central crossbar has a clamp for fixing a slump cone. The central crossbar and the clamp are raised and lowered by the lifting mechanism. The upper end of the steel pipe has an upper crossbar extending radially from the steel pipe, and the end of the upper crossbar has an image acquisition device for capturing images of the testing platform surface. The central crossbar and the upper crossbar form a horizontal angle. Concentric reference circles, used for visual recognition, are provided on the testing platform surface.

2. The concrete spread measurement device according to claim 1, characterized in that: A level is installed on the side of the test platform.

3. The concrete spread measurement device according to claim 1, characterized in that: The second motor is located inside the bottom of the steel pipe. The lifting mechanism includes a nut that slides inside the steel pipe and a vertically arranged screw. The nut is threaded onto the screw. The lower end of the screw is connected to the second motor, which drives the screw to rotate. The steel pipe has a vertically extending opening on its wall. The middle crossbar passes through the opening and is fixedly connected to the nut.

4. The concrete spread measurement device according to claim 1, characterized in that: The transmission mechanism includes a driven gear located at the lower end of the steel pipe and a driving gear located on the first motor, wherein the driven gear meshes with the driving gear.

5. The concrete spread measurement device according to claim 1, characterized in that: The reference circle is a circular marking on the test platform surface.

6. The concrete spread measurement device according to claim 1, characterized in that: The test platform surface, except for the reference circle, is coated with a reflective coating.

7. The concrete spread measurement device according to claim 1, characterized in that: The image acquisition device includes a downward-facing camera, a downward-facing fill light, and a downward-facing laser sight.

8. The concrete spread measurement device according to claim 7, characterized in that: The test platform is equipped with height-adjustable casters at its bottom.

9. The concrete spread measurement device according to claim 1, characterized in that: The upper periphery of the slump cylinder is provided with a support member, and the support member is provided with outward protrusions for supporting the clamp.

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