A testing device and method for testing the freeze-thaw plasticity of self-compacting concrete

Abstract

This invention discloses a device and method for testing the freeze-thaw plasticity of self-compacting concrete, relating to the field of concrete testing technology. The device includes a fixed plate with a suspended support plate above its top surface. The top surface of the support plate has several circularly arranged arc-shaped plates, which are joined together to form a circular ring. The top surface of the support plate also has several circularly arranged fixing lugs, each corresponding to one of the arc-shaped plates. The outer ring of the support plate has several circularly arranged rectangular notches. Each rectangular notch contains a rotatably connected notch gear. A limiting swing arm is fixed to the notch portion of each notch gear. A U-shaped plate is fixed to the top of each limiting swing arm, and a pressure sensor is installed in the opening of each U-shaped plate. This invention facilitates the reuse of the testing device and improves the accuracy of concrete freeze-thaw plasticity testing.

Description

Technical Field

[0001] This invention relates to the field of concrete testing technology, and in particular to a testing device and method for testing the freeze-thaw plasticity of self-compacting concrete. Background Technology

[0002] A Chinese invention patent (publication number: CN111881593B) discloses a method for testing the freeze-thaw plasticity of concrete. This method involves a special fabrication and pretreatment process for freeze-thaw concrete specimens, followed by obtaining the dynamic elastic modulus of the specimens through freeze-thaw cycle testing. This method effectively yields highly accurate dynamic elastic modulus measurements that closely reflect actual freeze-thaw conditions. Furthermore, by using the loss of dynamic elastic modulus as a loss variable, a freeze-thaw plasticity damage model for concrete is established. This damage accumulation model is successfully applied to the freeze-thaw plasticity testing of concrete under service conditions, effectively detecting the freeze-thaw plasticity of concrete and enabling the assessment of strength, stress, and strain relationships under freeze-thaw damage. The method boasts high accuracy and a high degree of consistency with actual environmental effects.

[0003] The following disadvantages exist in the freeze-thaw plasticity testing of self-compacting concrete: 1. Each test of self-compacting concrete requires the template to be reset and the concrete poured to facilitate subsequent freeze-thaw plasticity testing, and the existing testing equipment cannot be reused multiple times; 2. The freeze-thaw plasticity of concrete is mostly measured by external test data, which has poor testing effect and low accuracy. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing self-compacting concrete freeze-thaw plasticity testing devices, such as the inability to be reused and poor testing results, and to propose a self-compacting concrete freeze-thaw plasticity testing device and its testing method.

[0005] To address the problems of existing self-compacting concrete freeze-thaw plasticity testing devices being unreusable and having poor testing results, this invention adopts the following technical solution:

[0006] The device for testing the freeze-thaw plasticity of self-compacting concrete includes a fixed plate, a support plate suspended above the top surface of the fixed plate, a plurality of circularly arranged arc plates on the top surface of the support plate, the plurality of arc plates being spliced ​​together to form a circular ring, and a plurality of circularly arranged fixing lugs on the top surface of the support plate, the plurality of fixing lugs corresponding one-to-one with the plurality of arc plates.

[0007] The outer ring surface of the support plate has several rectangular notches arranged in a circular pattern. Each rectangular notch has a notch gear that is rotatably connected inside. Each notch gear has a limiting swing arm fixedly attached to its notch portion. Each limiting swing arm has a U-shaped plate fixedly attached to its top end. Each U-shaped plate has a pressure detection sensor installed in its opening.

[0008] Preferably, each of the fixed lugs is provided with a threaded first screw inserted in the middle, the inner end of each first screw is rotatably connected to the middle of the outer side wall of the corresponding arc plate, and the outer end of each first screw is fixed with a widened gear, and a T-shaped rod is fixed to the middle of the outer side of one of the widened gears.

[0009] Preferably, the top surface of the support plate is provided with a concentrically fixed channel steel ring, and a rotatably connected gear ring is engaged inside the channel steel ring. The gear ring is sequentially engaged and slidably connected with a plurality of widened gears.

[0010] Preferably, the U-shaped plate has a movably hinged rectangular sleeve inside the opening, a threaded second screw is inserted into the middle of the rectangular sleeve, and the pressure detection sensor is fixed at the bottom end of the second screw.

[0011] Preferably, a pair of vertically distributed buffer springs are fixed inside the opening of the U-shaped plate, and the inner ends of the pair of buffer springs are fixedly connected to the corresponding rectangular sleeves.

[0012] Preferably, the bottom surface of the support plate is fixed with a plurality of circularly arranged U-shaped clamping plates, each U-shaped clamping plate having a slidably connected cross slide plate inside, and each cross slide plate having a rack fixed on its top surface, each rack meshing with a corresponding notched gear.

[0013] Preferably, a servo motor with its output end facing upward is fixedly mounted on the center of the top surface of the fixed disk, and a limiting disk concentrically fixed to the top of the servo motor is fitted on the top of the servo motor, and the limiting disk has a plurality of staggered limiting pin holes.

[0014] Preferably, a limiting pin is fixed to the inner end of the bottom surface of each cross slide plate, and the bottom end of each pin is slidably engaged inside the corresponding limiting pin hole.

[0015] Preferably, the outer ring surface of the support disk is fixed with a plurality of circularly arranged support rods, and the plurality of support rods are staggered with a plurality of rectangular notches, and the bottom end of each support rod is fixedly connected to the top surface of the fixed disk.

[0016] This invention also proposes a testing method for the freeze-thaw plasticity testing device of self-compacting concrete, comprising the following steps:

[0017] Step 1: Rotate the T-shaped rod to drive the corresponding widened gear and the first screw to rotate. The widened gear meshes and drives the gear ring to rotate along the channel steel ring. The gear ring meshes and drives the remaining widened gears and the first screw to rotate. The first screw and the fixed lug thread work together to drive several arc plates to splice into a circular ring. Then, pour an appropriate amount of self-compacting concrete into it and let it stand for a period of time.

[0018] Step 2: Rotate the second screw. The threaded action between the second screw and the rectangular sleeve causes the pressure sensor to rise and fall to a suitable position, ensuring that several pressure sensors maintain the same height.

[0019] Step 3: Start the servo motor. The motor shaft of the servo motor drives the limit plate to rotate synchronously. The limit pin hole on the limit plate and the limit pin shaft on the cross slide form a limiting effect, driving the cross slide and rack to slide outward along the U-shaped plate. The rack meshes and drives the notched gear and the limit swing arm to swing inward, so that several pressure detection sensors are pressed against the self-compacting concrete. The freeze-thaw plasticity of the self-compacting concrete is detected by the pressure detection sensors.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. In this invention, several arc-shaped plates are spliced ​​into a circular ring, and an appropriate amount of self-compacting concrete is poured into it and left to stand for a period of time. This facilitates the experimental casting and molding of the self-compacting concrete, and also facilitates the demolding of the self-compacting concrete in the later stage. The self-compacting concrete can be reused multiple times through this testing device.

[0022] 2. In this invention, the limiting pin hole on the limiting plate and the limiting pin shaft on the cross slide form a limiting effect, driving several limiting swing arms to swing inward synchronously, so that several pressure detection sensors are pressed against the self-compacting concrete, and the freeze-thaw plasticity of the self-compacting concrete is detected by the pressure detection sensors.

[0023] In summary, this invention solves the problems of non-reusability and poor testing effect of self-compacting concrete freeze-thaw plasticity testing device. Moreover, the overall structure is compact, which not only facilitates the reuse of the testing device, but also improves the accuracy of concrete freeze-thaw plasticity testing. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0025] Figure 1 This is a schematic diagram of the main structure of the present invention;

[0026] Figure 2 This is a cross-sectional view of the main structure of the present invention;

[0027] Figure 3 This is an exploded view of the main structure of the present invention;

[0028] Figure 4This is a schematic diagram of the gear ring of the present invention meshing with several widened gears;

[0029] Figure 5 This is a schematic diagram of the engagement between the limiting disk and several limiting pins of the present invention;

[0030] Figure 6 This is a schematic diagram of the detection method of the present invention;

[0031] The numbers in the diagram are as follows: 1. Fixed plate; 11. Servo motor; 12. Limiting plate; 13. U-shaped clamping plate; 14. Cross slide plate; 15. Notched gear; 16. Limiting swing arm; 2. Support plate; 21. Arc plate; 22. Fixed lug; 23. First screw; 24. Widened gear; 25. Gear ring; 3. U-shaped plate; 31. Rectangular sleeve; 32. Second screw; 33. Pressure detection sensor. Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] Example 1: This example provides a device for testing the freeze-thaw plasticity of self-compacting concrete. See [link to example]. Figure 1-5 Specifically, it includes a fixed plate 1, a suspended support plate 2 above the top surface of the fixed plate 1, a number of circularly arranged arc plates 21 on the top surface of the support plate 2, the number of arc plates 21 spliced ​​together to form a circular ring, and a number of circularly arranged fixing ears 22 on the top surface of the support plate 2, the number of fixing ears 22 corresponding one-to-one with the number of arc plates 21.

[0034] The outer ring surface of the support plate 2 has several rectangular notches arranged in a circular pattern. Each rectangular notch has a notch gear 15 that is rotatably connected inside. Each notch gear 15 has a limiting swing arm 16 fixedly installed in the notch part. Each limiting swing arm 16 has a U-shaped plate 3 fixedly installed at the top end. Each U-shaped plate 3 has a pressure detection sensor 33 installed in the opening.

[0035] In the specific implementation process, such as Figure 3 and Figure 4 As shown, each fixed lug 22 has a threaded first screw 23 inserted in the middle. The inner end of each first screw 23 is rotatably connected to the middle of the outer wall of the corresponding arc plate 21. The outer end of each first screw 23 is fixed with a widened gear 24. A T-shaped rod is fixed in the middle of the outer side of one of the widened gears 24. Rotating the T-shaped rod drives the corresponding widened gear 24 and the first screw 23 to rotate. The widened gear 24 meshes and drives the gear ring 25 to rotate along the channel steel ring.

[0036] The top surface of the support plate 2 is provided with a concentrically fixed channel steel ring. The inside of the channel steel ring is a rotatably connected gear ring 25. The gear ring 25 is sequentially engaged and slidably connected with several widened gears 24. The engagement of the gear ring 25 drives the remaining widened gears 24 and the first screw 23 to rotate. The first screw 23 and the fixed lug 22 are threaded together, causing several arc plates 21 to be spliced ​​into a circular ring.

[0037] In the specific implementation process, such as Figure 1 and Figure 2 As shown, a rectangular sleeve 31 with a movable hinge is provided in the opening of the U-shaped plate 3. A second screw 32 with a threaded through-hole is inserted in the middle of the rectangular sleeve 31. The pressure detection sensor 33 is fixed at the bottom end of the second screw 32. A pair of buffer springs distributed vertically are fixed in the opening of the U-shaped plate 3. The inner ends of the pair of buffer springs are fixed to the corresponding rectangular sleeves 31. When the second screw 32 is rotated, the thread of the second screw 32 and the rectangular sleeve 31 drives the pressure detection sensor 33 to rise and fall to a suitable position, so that several pressure detection sensors 33 maintain the same height position.

[0038] It should be noted that in this embodiment, a number of circularly arranged support rods are fixed on the outer ring surface of the support plate 2. The support rods and the rectangular notches are distributed alternately. The bottom end of each support rod is fixed to the top surface of the fixed plate 1. The support rods increase the stability of the connection between the fixed plate 1 and the support plate 2.

[0039] Example 2: In Example 1, there was a problem that several limiting arms 16 could not swing inward synchronously. Therefore, based on Example 1, this example also includes:

[0040] In the specific implementation process, such as Figure 3 and Figure 5 As shown, the bottom surface of the support plate 2 is fixed with several circularly arranged U-shaped clamping plates 13. Each U-shaped clamping plate 13 has a sliding cross-shaped sliding plate 14 inside. The top surface of each cross-shaped sliding plate 14 is fixed with a rack. Each rack is meshed with a corresponding notched gear 15. The meshing of the rack drives the notched gear 15 and the limiting swing arm 16 to swing inward, so that several pressure detection sensors 33 are pressed against the self-compacting concrete.

[0041] A servo motor 11 with its output end facing upward is fixedly mounted on the center of the top surface of the fixed disk 1. A limiting disk 12 is concentrically fixedly mounted on the top of the servo motor 11. The limiting disk 12 has several staggered limiting pin holes. A limiting pin is fixedly mounted on the inner end of the bottom surface of each cross slide plate 14. The bottom end of each pin is slidably engaged in the interior of the corresponding limiting pin hole. The motor shaft of the servo motor 11 drives the limiting disk 12 to rotate synchronously. The limiting pin holes on the limiting disk 12 and the limiting pins on the cross slide plate 14 form a limiting effect, driving the cross slide plate 14 and the rack to slide outward along the U-shaped clamping plate 13.

[0042] Example 3: See Figure 6 Specifically, the working principle and operation method of this invention are as follows:

[0043] Step 1: Rotate the T-shaped rod to drive the corresponding widened gear 24 and the first screw 23 to rotate. The widened gear 24 meshes and drives the gear ring 25 to rotate along the channel steel ring. The gear ring 25 meshes and drives the remaining widened gears 24 and the first screw 23 to rotate. The thread action of the first screw 23 and the fixed lug 22 drives several arc plates 21 to be spliced ​​into a circular ring, and an appropriate amount of self-compacting concrete is poured into it and left to stand for a period of time.

[0044] Step 2: Rotate the second screw 32. The thread action between the second screw 32 and the rectangular sleeve 31 drives the pressure detection sensor 33 to rise and fall to a suitable position, and keeps several pressure detection sensors 33 at the same height.

[0045] Step 3: Start the servo motor 11. The motor shaft of the servo motor 11 drives the limiting disk 12 to rotate synchronously. The limiting pin hole on the limiting disk 12 and the limiting pin shaft on the cross slide plate 14 form a limiting effect, driving the cross slide plate 14 and the rack to slide outward along the U-shaped clamp plate 13. The rack meshes and drives the notched gear 15 and the limiting swing arm 16 to swing inward, so that several pressure detection sensors 33 are all pressed against the self-compacting concrete, and the freeze-thaw plasticity of the self-compacting concrete is detected by the pressure detection sensors 33.

[0046] This invention solves the problems of the self-compacting concrete freeze-thaw plasticity testing device being unreusable and having poor testing results. Moreover, the overall structure is compact, which not only facilitates the reuse of the testing device but also improves the accuracy of concrete freeze-thaw plasticity testing.

[0047] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for testing the freeze-thaw plasticity of self-compacting concrete, comprising a fixed plate (1), characterized in that: The top surface of the fixed plate (1) is provided with a suspended support plate (2). The top surface of the support plate (2) is provided with a number of circularly arranged arc plates (21). The arc plates (21) are spliced ​​together to form a circular ring. The top surface of the support plate (2) is provided with a number of circularly arranged fixed ear seats (22). The fixed ear seats (22) correspond one-to-one with the arc plates (21). The outer ring surface of the support plate (2) is provided with several rectangular notches arranged in a circular pattern. Each rectangular notch is provided with a notch gear (15) that is rotatably connected inside. Each notch gear (15) is fixed with a limiting swing arm (16) in the notch portion. Each limiting swing arm (16) is fixed with a U-shaped plate (3) at the top end. Each U-shaped plate (3) is installed with a pressure detection sensor (33) in the opening. Each of the fixed lugs (22) is provided with a threaded first screw (23) inserted in the middle. The inner end of each first screw (23) is rotatably connected to the middle of the outer side wall of the corresponding arc plate (21). The outer end of each first screw (23) is fixed with a widened gear (24). A T-shaped rod is fixed in the middle of the outer side of one of the widened gears (24). The top surface of the support plate (2) is provided with a concentrically fixed channel steel ring, and a rotatably connected gear ring (25) is engaged inside the channel steel ring. The gear ring (25) is sequentially meshed and slidably connected with a number of widened gears (24). The U-shaped plate (3) has a movable hinged rectangular sleeve (31) inside the opening. A threaded second screw (32) is inserted in the middle of the rectangular sleeve (31). The pressure detection sensor (33) is fixed at the bottom end of the second screw (32). The bottom surface of the support plate (2) is fixed with a number of circularly arranged U-shaped plates (13). Each U-shaped plate (13) has a sliding cross plate (14) inside it. The top surface of each cross plate (14) is fixed with a rack, and each rack is meshed with a corresponding notched gear (15).

2. The device for testing the freeze-thaw plasticity of self-compacting concrete according to claim 1, characterized in that: A pair of buffer springs distributed vertically are fixed inside the opening of the U-shaped plate (3), and the inner ends of the pair of buffer springs are fixed to the corresponding rectangular sleeves (31).

3. The device for testing the freeze-thaw plasticity of self-compacting concrete according to claim 2, characterized in that: The top surface of the fixed disk (1) is fixed with a servo motor (11) with the output end facing upward. The top of the servo motor (11) is fitted with a concentrically fixed limiting disk (12). The limiting disk (12) has several staggered limiting pin holes.

4. The device for testing the freeze-thaw plasticity of self-compacting concrete according to claim 3, characterized in that: Each of the cross slide plates (14) has a limiting pin fixed at its bottom inner end, and the bottom end of each pin is slidably engaged in the interior of the corresponding limiting pin hole.

5. The device for testing the freeze-thaw plasticity of self-compacting concrete according to claim 4, characterized in that: The outer ring surface of the support plate (2) is fixed with a number of circularly arranged support rods, and the support rods are staggered with a number of rectangular notches. The bottom end of each support rod is fixed to the top surface of the fixed plate (1).

6. The detection method of the self-compacting concrete freeze-thaw plasticity testing device according to claim 5, characterized in that, Includes the following steps: Step 1: Rotate the T-shaped rod to drive the corresponding widened gear (24) and the first screw (23) to rotate. The widened gear (24) meshes and drives the gear ring (25) to rotate along the channel steel ring. The gear ring (25) meshes and drives the remaining widened gears (24) and the first screw (23) to rotate. The first screw (23) and the fixed ear seat (22) threaded together to drive several arc plates (21) to splice into a circular ring. Then, pour an appropriate amount of self-compacting concrete into it and let it stand for a period of time. Step 2: Rotate the second screw (32). The thread action between the second screw (32) and the rectangular sleeve (31) drives the pressure detection sensor (33) to rise and fall to a suitable position, and keeps several pressure detection sensors (33) at the same height. Step 3: Start the servo motor (11). The motor shaft of the servo motor (11) drives the limiting disk (12) to rotate synchronously. The limiting pin hole on the limiting disk (12) and the limiting pin shaft on the cross slide plate (14) form a limiting effect, driving the cross slide plate (14) and the rack to slide outward along the U-shaped plate (13). The rack meshes and drives the notched gear (15) and the limiting swing arm (16) to swing inward, so that several pressure detection sensors (33) are pressed against the self-compacting concrete, and the freeze-thaw plasticity of the self-compacting concrete is detected by the pressure detection sensors (33).

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