A shrinkage detection device suitable for concrete test pieces of various sizes

Abstract

The application relates to a shrinkage detection device suitable for concrete test pieces of multiple sizes, and belongs to the technical field of building material detection. The detection device comprises a base, a first side plate fixed to one end of the base, a push plate movable along the length direction of the base, and a driving mechanism for driving the push plate. At least two grooves for placing concrete test pieces of different width sizes are formed in the length direction of the base. A distance meter corresponding to the groove position is installed on the push plate, which is used for non-contact measurement of the distance between the push plate and the first side plate to determine the length of the concrete test piece. By arranging multiple grooves of different specifications, the detection device realizes the detection capability of a single device compatible with multiple sizes of concrete test pieces, and solves the poor universality problem of the prior art. In addition, the detection device also integrates automatic cleaning and slag removal, contact sensor positioning, leveler leveling and other functions, thereby improving the automation degree, precision and reliability of detection.

Description

Technical Field

[0001] This utility model relates to the field of building material testing technology, and in particular to a device for testing the shrinkage rate of concrete specimens. Background Technology

[0002] Concrete inevitably shrinks during the hardening process, a phenomenon that directly affects the long-term performance and durability of structures. Therefore, investigating the shrinkage mechanism and influencing factors through shrinkage rate testing is crucial for materials research and engineering quality control.

[0003] Existing methods for measuring the shrinkage rate of concrete specimens mostly employ fixed rods and dial indicators, requiring manual reading and recording. This results in low data acquisition efficiency and is prone to operational errors. To detect long-term shrinkage changes in concrete specimens, the same specimen must be tested multiple times to ensure data accuracy. Each test requires strict alignment with the initial marking position, a process that is not only time-consuming and labor-intensive but also susceptible to data deviation due to specimen movement or marking errors. Furthermore, cement-based materials are diverse, and their specimen specifications vary. Existing equipment is often specifically designed for specimens of particular sizes, lacking versatility and compatibility.

[0004] In summary, it is of great significance to develop an automated and versatile shrinkage rate detection device to overcome the inherent defects of existing detection methods. Utility Model Content

[0005] To address the problem that existing technologies can only be adapted to one type of concrete specimen, resulting in poor equipment versatility, this invention provides a shrinkage rate testing device suitable for concrete specimens of multiple sizes.

[0006] The shrinkage rate testing device for multi-size concrete specimens provided in this application adopts the following technical solution: A shrinkage rate testing device suitable for multi-size concrete specimens includes a base, a first side plate, a push plate, and a driving mechanism. The first side plate is disposed at one end of the base. The push plate is movable along the length of the base. The driving mechanism is used to drive the push plate closer to or away from the first side plate. The first side plate and the push plate can abut against both ends of the concrete specimen. The base has at least two grooves along its length for placing concrete specimens of different widths. A distance measuring instrument corresponding to the position of the groove is installed on the push plate. The distance measuring instrument is used to measure the distance between the push plate and the first side plate multiple times in a non-contact manner.

[0007] By adopting the above technical solution, this application provides a measurement platform integrating a fixed side plate, a movable push plate, and a drive mechanism. Furthermore, by setting at least two grooves of different specifications on the base, a single device can be compatible with concrete specimens of various widths, improving the device's versatility. Simultaneously, by using a rangefinder mounted on the movable push plate to directly measure the distance between it and the fixed side plate, i.e., the length of the concrete specimen, the measurement method is direct and accurate.

[0008] Optionally, the base has three grooves, including a first groove, a second groove arranged in parallel, and a third groove disposed above the first groove and the second groove and forming a stepped structure therewith; the width of the first groove is smaller than the width of the second groove, and the width of the second groove is smaller than the width of the third groove.

[0009] By adopting the above technical solution, the specific layout of the groove was optimized and defined, employing a stepped structure consisting of two parallel narrow grooves and a wide groove above them, with the width of the three grooves increasing progressively. This design not only allows for the efficient use of space by accommodating three different sizes of concrete specimens within the limited base width, making the overall structure more compact, but the stepped layout also facilitates the handling and placement of concrete specimens of different sizes by operators.

[0010] Optionally, the rangefinder is mounted on the push plate, and the rangefinder is positioned at a certain height so that concrete specimens of different sizes do not obstruct the rangefinder.

[0011] By adopting the above technical solution, it is determined that the installation position of the rangefinder must be higher than the highest concrete specimen that can be placed in its corresponding groove. This design ensures that the rangefinder's measuring path will not be obstructed by the concrete specimen body, regardless of the size of the concrete specimen placed, guaranteeing that the rangefinder can always accurately measure the fixed side plate at the far end. This is the basic prerequisite and structural guarantee for achieving effective measurement of concrete specimens of all compatible sizes.

[0012] Optionally, the first side plate has a slag discharge port, which is connected to the groove; when the push plate approaches the first side plate, the push plate pushes the residue in the groove toward the slag discharge port.

[0013] By adopting the above technical solution, a slag discharge port communicating with the groove is opened at the fixed side plate, and the groove is actively cleaned by the reciprocating movement of the push plate. With this design, the testing device can automatically clean the measurement area before each measurement, effectively removing concrete debris and other residues that may affect the stable placement of the concrete specimen. This ensures that the concrete specimen is always in contact with a clean reference surface, eliminating measurement errors caused by residues at the source and improving the reliability of the measurement.

[0014] Optionally, a limiting block is provided at the corresponding position of the slag discharge port and the end of the groove. The limiting block can abut against the concrete specimen. The width of the limiting block is smaller than the groove width. A slag discharge space is reserved between the limiting block and the groove port.

[0015] By adopting the above technical solution, a limiting block with a width smaller than the groove is set near the slag discharge port. This design provides the limiting block with a precise end contact point for the concrete specimen, serving as an auxiliary positioning element. Furthermore, because the limiting block is narrower than the groove, a slag discharge channel is naturally formed between the limiting block and the groove wall, ensuring that the residue pushed by the push plate can pass smoothly and enter the slag discharge port, avoiding blockage problems.

[0016] Optionally, one side of the base relative to the slag discharge port is designed as an inclined surface.

[0017] By adopting the above technical solution, the side of the base below the slag discharge port is designed as an inclined slope. With this design, the concrete residue discharged from the slag discharge port can automatically slide off to the outside of the equipment due to gravity, avoiding the accumulation of residue near the slag discharge port and causing secondary blockage or pollution. This achieves excellent slag discharge effect and further improves the automation level and long-term ease of use of the equipment.

[0018] Optionally, the detection device further includes a contact sensor and a controller. The contact sensor is disposed on the push plate and is used to detect whether the push plate is in contact with the end face of the concrete specimen. The controller is electrically connected to the drive mechanism and the contact sensor.

[0019] By adopting the above technical solution, a contact sensor and controller were introduced to construct a closed-loop automatic positioning system. With this design, when the push plate moves and contacts the end face of the concrete specimen, the contact sensor immediately triggers a signal, and the controller, upon receiving the signal, precisely stops the drive mechanism. This achieves automated, repeatable, and flexible clamping of the concrete specimen, avoiding positional deviations caused by uneven force during manual positioning, and ensuring highly consistent starting conditions for each measurement.

[0020] Optionally, the drive mechanism includes a motor, a lead screw, and a guide rod. The motor is connected to the lead screw via a transmission, and the guide rod is fixed to the first side plate and parallel to the lead screw. The push plate is threaded to the lead screw and slidably sleeved on the guide rod.

[0021] By adopting the above scheme, the drive mechanism is defined as consisting of a motor, a lead screw, and guide rods. This design utilizes the motor to drive the lead screw, precisely converting rotational motion into linear motion of the push plate, achieving a smooth and highly accurate drive effect. The parallel guide rods prevent the push plate from rotating or tilting during movement, ensuring the stability of the push plate's posture and providing mechanical assurance for the accuracy of laser ranging.

[0022] Optionally, a level is provided on the base.

[0023] By adopting the above technical solution, a level was added to the base. This design provides a direct reference standard for equipment installation and commissioning. Operators can observe the level to ensure that the entire measurement reference plane is absolutely level, which helps to eliminate the influence of gravity caused by equipment tilt and ensures high-precision measurement.

[0024] Optionally, a second side plate is provided on the base at the other end opposite to the first side plate, and a stop block is provided on the side of the second side plate facing the push plate, the stop block being able to abut against the push plate.

[0025] By adopting the above technical solution, a second side plate with a stop is provided at the other end of the base. This design provides physical limitation protection for the movement range of the push plate.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. This application cleverly designs multiple grooves of different specifications on the base, enabling the ranging system to adapt to the measurement of all grooves, thus allowing a single device to be compatible with concrete specimens of various standard sizes. Compared with the existing technology's "one device for one size" approach, this greatly improves the device's versatility and cost-effectiveness.

[0027] 2. This application integrates motor drive, contact sensor positioning, active slag removal, and non-contact ranging into one unit, realizing full automation from cleaning and clamping positioning to data reading. This not only frees operators from tedious and repetitive manual adjustments, greatly improving detection efficiency, but also eliminates random errors introduced by human operation through precise program control, ensuring high accuracy and repeatability of measurement results.

[0028] 3. The combination design of the active slag discharge port and the limiting block in this application ensures the long-term cleanliness of the measurement reference; the stepped groove layout optimizes space utilization; the combination of the lead screw and guide rod ensures smooth and precise movement of the push plate; and auxiliary structures such as the stop block and level further enhance the safety of the equipment and the basic accuracy of the measurement. These optimized structural designs work together to ensure that the detection device can perform high-precision measurements stably and reliably for a long time. Attached Figure Description

[0029] Figure 1 This is a full view of a shrinkage rate testing device suitable for concrete specimens of various sizes.

[0030] Figure 2 This is another perspective view of a shrinkage rate testing device suitable for concrete specimens of various sizes.

[0031] Figure 3 This is a side view of a shrinkage rate testing device suitable for concrete specimens of various sizes.

[0032] Figure 4 This is a top view of a shrinkage rate testing device suitable for concrete specimens of various sizes.

[0033] Explanation of reference numerals in the attached drawings: 1. Base; 2. First side plate; 3. Push plate; 4. Drive mechanism; 41. Motor; 42. Lead screw; 43. Guide rod; 5. Groove; 51. First groove; 52. Second groove; 53. Third groove; 6. Rangefinder; 7. Slag discharge port; 8. Limit block; 9. Controller; 10. Contact sensor; 11. Level; 12. Second side plate; 13. Stop block. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0035] Reference Figure 1 This utility model provides a shrinkage rate testing device suitable for concrete specimens of various sizes. It mainly includes a base 1, with a first side plate 2 vertically fixed at one end of the base 1; a push plate 3 is movably disposed on the base 1, and its moving direction is along the length direction of the base 1; the testing device also includes a driving mechanism 4, which drives the push plate 3 along the length direction of the base 1 to move closer to or away from the first side plate 2; during measurement, the concrete specimen is placed between the first side plate 2 and the push plate 3, with its two ends abutting against the inner side wall of the first side plate 2 and the inner side wall of the push plate 3, respectively.

[0036] Specifically, the base 1 has at least two grooves 5 along its length for placing concrete specimens of different widths. In this embodiment, multiple grooves 5 are provided to accommodate standard concrete specimens with different cross-sectional dimensions, such as 40mm×40mm and 100mm×100mm.

[0037] Specifically, a distance measuring instrument 6 is installed on the push plate 3, corresponding to the position of the groove 5. The optical path of the distance measuring instrument 6 is directly facing the first side plate 2, and it is used to measure the distance between the push plate 3 and the first side plate 2 in a non-contact manner. Preferably, the distance measuring instrument 6 is a laser displacement sensor. Since the two ends of the concrete specimen are abutted by the first side plate 2 and the push plate 3, the distance measured by the distance measuring instrument 6 is the real-time length of the concrete specimen. By taking multiple measurements at different time points (such as 1 day after specimen molding, 7 days after specimen molding, 28 days after specimen molding, etc.), the shrinkage amount and shrinkage rate of the concrete specimen can be calculated.

[0038] Reference Figure 2 In this preferred embodiment, three grooves 5 are formed on the base 1. Specifically, the three grooves 5 are arranged as follows: two narrower grooves, the first groove 51 and the second groove 52, are arranged parallel to each other on the lower layer of the base 1; the widest groove, the third groove 53, is arranged above the first grooves 51 and the second grooves 52, forming a stepped structure together. Specifically, the width of the first groove 51 is smaller than the width of the second groove 52, and the width of the second groove 52 is smaller than the width of the third groove 53. This stepped layout not only makes the structure compact and efficiently utilizes the space of the base 1, but also facilitates quick and accurate placement and removal of concrete specimens by operators according to their dimensions.

[0039] Reference Figure 1 and Figure 2 To ensure the validity of the measurement, the installation position of the rangefinder 6 on the push plate 3 has been carefully designed. Specifically, the installation height of the rangefinder 6 needs to be calculated to ensure that its position is higher than the upper surface of the largest concrete specimen that can be placed in its corresponding groove 5. With this design, regardless of the size of the concrete specimen placed in the groove 5, the concrete specimen will not obstruct the path of the rangefinder 6 for emitting and receiving laser light, thus ensuring that the measurement can always be carried out reliably.

[0040] To address the technical issue of concrete residue affecting measurement accuracy, this testing device also features an active slag removal function. Specifically, one or more slag discharge ports 7 are provided at the lower part of the first side plate 2. These ports 7 are connected to the end of the groove 5 on the base 1. Before or after each measurement, the drive mechanism 4 can drive the push plate 3 to move a full stroke along the groove 5 from the end furthest from the first side plate 2 towards the end closest to it. During this process, the front end of the push plate 3 acts like a scraper, pushing concrete debris, dust, and other residues remaining in the groove 5 towards the first side plate 2, and ultimately ejecting them from the slag discharge port 7, thereby achieving automatic cleaning of the measurement area.

[0041] Reference Figure 2 and Figure 3 To provide a stable positioning reference for the concrete specimen while achieving slag removal, two limiting blocks 8 are set at the upper edge of the slag discharge port 7, i.e., at the ends of the first groove 51 and the second groove 52. The function of these two limiting blocks 8 is to serve as the final contact surface for one end of the concrete specimen. The width of these two limiting blocks 8 is designed to be smaller than the groove width of the groove 5 in which they are located. Through this design, slag discharge space is naturally reserved between the two sides of the limiting blocks 8 and the side walls of the groove 5, and between the lower edge of the limiting blocks 8 and the bottom of the groove 5. When the push plate 3 pushes the residue to this point, the residue can smoothly enter the slag discharge port 7 through these spaces, while the end face of the concrete specimen can stably abut against the flat surface of the limiting blocks 8, ensuring that the end face of the concrete specimen can stably abut against the limiting blocks 8, which serve as the reference surface.

[0042] To facilitate the collection and treatment of the discharged residue, the base 1 of this detection device is designed with an outward and downward sloping surface on the side where the discharge port 7 is located, based on the aforementioned discharge port 7. In this way, the residue falling from the discharge port 7 will automatically slide down this sloping surface to a designated area outside the equipment due to gravity, preventing accumulation directly below the discharge port 7 and ensuring the long-term unobstructed flow of the discharge channel.

[0043] Reference Figure 1 and Figure 4To achieve automated and precise positioning, this testing device also includes a controller 9 and a contact sensor 10 mounted on the inner wall of the push plate 3. Preferably, the controller 9 is a PLC; the contact sensor 10 is a pressure sensor. The controller 9 is electrically connected to both the drive mechanism 4 and the contact sensor 10. When it is necessary to clamp the concrete specimen, the controller 9 controls the drive mechanism 4 to drive the push plate 3 to move towards the first side plate 2. When the inner wall of the push plate 3 just contacts the end face of the concrete specimen and applies a very small preset pressure, the contact sensor 10 is triggered and sends a signal to the controller 9. Upon receiving the signal, the controller 9 immediately stops the drive mechanism 4. This closed-loop control process achieves rapid, precise, and consistent automatic positioning of the concrete specimen.

[0044] Reference Figure 4 In this embodiment, the drive mechanism 4 consists of a motor 41, a lead screw 42, and a guide rod 43. Preferably, the motor 41 is a stepper motor, which is connected to the lead screw 42 via a coupling or other means. The guide rod 43 is kept strictly parallel to the lead screw 42. The push plate 3 has a nut hole that mates with the threaded lead screw 42, allowing it to be threadedly connected to the lead screw 42. Simultaneously, the push plate 3 also has a smooth through hole, allowing it to slide onto the guide rod 43. When the motor 41 drives the lead screw 42 to rotate, the push plate 3 moves precisely in a straight line along the guide rail formed by the lead screw 42 and the guide rod 43. The presence of the guide rod 43 effectively prevents the push plate 3 from deflecting or wobbling during movement.

[0045] To ensure the reference level of the entire measurement system, two levels 11 are installed at an easily observable position on the upper surface of the base 1. Preferably, the levels 11 are bubble levels, and the two levels 11 are arranged in an inverted "T" shape to perform omnidirectional measurements simultaneously. After the equipment is initially installed or moved, the operator can adjust the position of the base 1 by observing the levels 11 to ensure that the entire equipment is in an absolutely level state, thereby eliminating measurement errors caused by tilting.

[0046] To limit the movement range of the push plate 3 and provide structural support for the drive mechanism 4, a second side plate 12 is fixedly installed on the base 1 at the other end opposite to the first side plate 2. The two ends of the guide rod 43 and the lead screw 42 can be fixed between the first side plate 2 and the second side plate 12, respectively. In addition, two stops 13 are provided on the side of the second side plate 12 facing the push plate 3. These two stops 13 serve as the physical limit positions for the movement of the push plate 3. When the push plate 3 moves away from the first side plate 2, it will eventually come into contact with these two stops 13 and stop. This can serve as the origin calibration position of the system and also plays an important safety protection role, preventing the push plate 3 from accidentally dislodging from the guide rail.

[0047] The implementation principle of a shrinkage rate detection device for multi-size concrete specimens according to an embodiment of this application is as follows: At the required test time, the operator places the concrete specimen to be tested into the corresponding groove 5 on the base 1 according to its size. The measurement program is started by the controller 9, and the drive mechanism 4 drives the push plate 3 to move towards the first side plate 2 until the contact sensor 10 detects that the push plate 3 is in contact with the end face of the concrete specimen and stops. At this time, the distance measuring instrument 6 on the push plate 3 records the distance L1 between the push plate 3 and the first side plate 2. The concrete specimen is placed in the curing environment required for the test. After curing for a certain period, the concrete specimen is placed back into the corresponding groove 5, and the measurement program is started again, repeating the above automatic positioning process, and the length L2 is measured at this time. The shrinkage of the concrete specimen is ΔL = L1 - L2, and the shrinkage rate of the concrete specimen can be calculated based on the initial length L1.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. All equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A shrinkage rate testing device suitable for concrete specimens of various sizes, characterized in that, The device includes a base (1), a first side plate (2), a push plate (3), and a drive mechanism (4). The first side plate (2) is disposed at one end of the base (1). The push plate (3) can move along the length of the base (1). The drive mechanism (4) is used to drive the push plate (3) to move closer to or away from the first side plate (2). The first side plate (2) and the push plate (3) can abut against both ends of the concrete specimen. The base (1) has at least two grooves (5) along its length for placing specimens of different widths; the push plate (3) is equipped with a rangefinder (6) corresponding to the position of the groove (5), and the rangefinder (6) is used to measure the distance between the push plate (3) and the first side plate (2) multiple times in a non-contact manner.

2. The shrinkage rate testing device for multi-size concrete specimens according to claim 1, characterized in that, The base (1) has three grooves (5), which include a first groove (51) and a second groove (52) arranged in parallel, and a third groove (53) arranged above the first groove (51) and the second groove (52) and forming a stepped structure with them; the width of the first groove (51) is smaller than the width of the second groove (52), and the width of the second groove (52) is smaller than the width of the third groove (53).

3. The shrinkage rate testing device for multi-size concrete specimens according to claim 1, characterized in that, The rangefinder (6) is mounted on the push plate (3), and the rangefinder (6) is mounted at a certain height so that concrete specimens of different sizes will not obstruct the rangefinder (6).

4. The shrinkage rate testing device for multi-size concrete specimens according to claim 1, characterized in that, The first side plate (2) has a slag discharge port (7) which is connected to the groove (5); when the push plate (3) approaches the first side plate (2), the push plate (3) pushes the residue in the groove (5) toward the slag discharge port (7).

5. The shrinkage rate testing device for multi-size concrete specimens according to claim 4, characterized in that, A limiting block (8) is provided at the corresponding position of the slag discharge port (7) and the end of the groove (5). The limiting block (8) can abut against the concrete specimen. The width of the limiting block (8) is smaller than the groove width of the groove (5). A slag discharge space is reserved between the limiting block (8) and the end of the groove (5).

6. The shrinkage rate testing device for multi-size concrete specimens according to claim 4, characterized in that, The base (1) has one side sloped relative to the slag discharge port (7).

7. The shrinkage rate testing device for multi-size concrete specimens according to claim 1, characterized in that, The detection device also includes a contact sensor (10) and a controller (9). The contact sensor (10) is disposed on the push plate (3) and is used to detect whether the push plate (3) is in contact with the end face of the specimen. The controller (9) is electrically connected to the drive mechanism (4) and the contact sensor (10).

8. The shrinkage rate testing device for multi-size concrete specimens according to claim 1, characterized in that, The drive mechanism (4) includes a motor (41), a lead screw (42) and a guide rod (43). The motor (41) is connected to the lead screw (42) for transmission. The guide rod (43) is fixed to the first side plate (2) and parallel to the lead screw (42). The push plate (3) is connected to the lead screw (42) by a thread and is slidably sleeved on the guide rod (43).

9. The shrinkage rate testing device for multi-size concrete specimens according to claim 1, characterized in that, A level (11) is provided on the base (1).

10. The shrinkage rate testing device for multi-size concrete specimens according to claim 1, characterized in that, The base (1) has a second side plate (12) at the other end relative to the first side plate (2). The second side plate (12) has a stop (13) on the side facing the push plate (3). The stop (13) can abut against the push plate (3).

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