A device and method for detecting the bearing capacity of a concrete structure

Abstract

The application provides a concrete structure bearing capacity detection device and a detection method, and belongs to the technical field of building structure material detection. The detection device base and the protection box fixedly installed on the top of the base are provided, the lower spherical hinge support located in the protection box is fixedly installed on the top of the base, the lower steel base plate is installed on the bearing plate of the lower spherical hinge support, four limiting pins are fixedly installed on the bearing plate of the lower spherical hinge support, four limiting circular grooves are formed in the bottom of the lower steel base plate, and the diameter of the limiting pins is smaller than that of the limiting circular grooves; four L-shaped positioning blocks are installed on the middle region of the top of the lower steel base plate, and two groups of position correction mechanisms are arranged in the protection box. The concrete structure bearing capacity detection device has the advantages that the sample can be accurately positioned to improve the detection accuracy, and the residual materials can be automatically cleaned and collected to improve the operation convenience.

Description

Technical Field

[0001] This invention relates to the field of building structural material testing technology, and in particular to a device and method for testing the load-bearing capacity of concrete structures. Background Technology

[0002] In construction engineering, concrete load-bearing capacity testing is a crucial step in assessing structural safety and durability. The mainstream equipment is a hydraulic pressure testing machine, which obtains mechanical parameters by applying axial pressure to concrete samples. This type of equipment is typically equipped with upper and lower ball joint supports and upper and lower steel plates: the ball joint supports can compensate for the compression deformation of the sample by rotating the ball core, avoiding pressure deviation; the steel plates are in direct contact with the sample, uniformly transmitting pressure to the sample cross-section, reducing local stress concentration, and are the basic components for stable testing.

[0003] Existing concrete structure bearing capacity testing equipment suffers from difficulties in ensuring the centering of the sample during use. Most equipment relies on manual visual positioning, which is prone to operational errors that cause the sample center to deviate from the center of the steel plate. Even with the deformation compensation capability of the ball joint support, excessive sample positional deviation cannot offset the initial eccentricity, leading to eccentric loading, additional bending moment, and uneven stress distribution in the sample, easily resulting in distorted test data. Therefore, it is necessary to provide a concrete structure bearing capacity testing device and method to solve the above-mentioned technical problems. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a concrete structure bearing capacity testing device and testing method that can achieve precise sample positioning to improve testing accuracy and can automatically clean up residual materials and collect them centrally to improve operational convenience.

[0005] To solve the above-mentioned technical problems, the present invention provides a concrete structure bearing capacity testing device, including a base and a protective box fixedly installed on the top of the base. A lower ball joint support is fixedly installed on the top of the base and located inside the protective box. A lower steel pad is installed on the bearing plate of the lower ball joint support. A hydraulic pressure mechanism is also provided inside the protective box above the lower steel pad. Four limiting pins are fixedly installed on the bearing plate of the lower ball joint support. Four limiting circular grooves are opened at the bottom of the lower steel pad. The four limiting pins are respectively located in the four limiting circular grooves, and the diameter of the limiting pins is smaller than the diameter of the limiting circular grooves.

[0006] Four L-shaped positioning blocks are installed in the middle area of ​​the top of the lower steel pad, and the four L-shaped positioning blocks together form a square area, the center of which coincides with the center of the lower steel pad.

[0007] Ear blocks are fixedly installed on both outer walls of the lower steel pad. Two sets of position correction mechanisms are provided inside the protective box. The two sets of position correction mechanisms are used to cooperate with the ear blocks to accurately locate the horizontal plane position of the lower steel pad.

[0008] Preferably, any set of the position correction mechanisms includes a second hydraulic cylinder, a transverse transfer plate, two clamping blocks, a bidirectional lead screw, and a second electric motor. The transverse transfer plate is disposed on one side of the lower steel pad. The second hydraulic cylinder is fixedly installed on one outer wall of the protective box. The output end of the second hydraulic cylinder extends into the protective box and is fixedly connected to the transverse transfer plate. The two clamping blocks are slidably installed on the transverse transfer plate, and the corresponding lugs are located between the two clamping blocks. The bidirectional lead screw is rotatably installed on the transverse transfer plate and is threadedly connected to the two clamping blocks respectively. The second electric motor is fixedly installed on the transverse transfer plate, and the output end of the second electric motor is fixedly connected to one end of the corresponding bidirectional lead screw.

[0009] Furthermore, multiple contact rollers are rotatably mounted on the outer wall of the clamping block near the lower steel pad, and the multiple contact rollers are arranged at equal intervals.

[0010] Preferably, the top of the lower steel pad is provided with four L-shaped grooves, and the four L-shaped positioning blocks are slidably installed in the four L-shaped grooves respectively. The bottom of the lower steel pad is threaded with four mounting cylinders, and each of the four mounting cylinders is provided with a return spring. The top end of the return spring contacts the bottom of the L-shaped positioning block, and the bottom end contacts the bottom inner wall of the mounting cylinder. The protective box is provided with a cleaning mechanism for cleaning the concrete sample residue on the top of the lower steel pad.

[0011] Preferably, the cleaning mechanism includes two fixed slide rods, a lead screw, a push plate, and an electric motor. The two fixed slide rods are fixedly installed inside the protective box. The push plate is slidably sleeved on the two fixed slide rods. The lead screw is rotatably installed inside the protective box, passes through the push plate, and is threadedly connected to the push plate. The electric motor is fixedly installed on one outer wall of the protective box. One end of the lead screw extends outside the protective box and is fixedly connected to the output end of the electric motor. The bottom of the push plate and the connection between it and the left and right outer walls are both chamfered.

[0012] Furthermore, corrugated tubes are movably sleeved on both of the fixed sliding rods and the lead screw. One end of the corrugated tube is fixedly connected to the push plate, and the other end is fixedly connected to the inner wall of one side of the corresponding protective box.

[0013] Furthermore, two sets of pushing mechanisms are symmetrically arranged inside the protective box to push the concrete sample residue inside the protective box and located at the top of the base out of the protective box.

[0014] Each set of the pushing mechanism includes a second pusher plate, a third pusher plate, a rectangular pusher rod, and a third hydraulic cylinder. The second pusher plate is disposed inside the protective box, and the third pusher plate is slidably mounted on the second pusher plate. The bottoms of both the second and third pusher plates are in contact with the top of the base. Two fixed sliding rods are fixedly mounted on the second pusher plate, both of which pass through the third pusher plate and are slidably connected to the third pusher plate. A return spring is sleeved on the second fixed sliding rod, one end of which is fixedly connected to the third pusher plate and the other end of which is fixedly connected to the second pusher plate. The rectangular pusher rod is slidably mounted on the rear outer wall of the protective box, one end of which extends into the protective box and is fixedly connected to the second pusher plate. The third hydraulic cylinder is fixedly mounted on the top of the base and located on one side of the protective box. The output end of the third hydraulic cylinder is fixedly connected to the end of the rectangular pusher rod located outside the protective box.

[0015] Furthermore, partition blocks are fixedly installed on both the front and rear sides of the lower ball joint support. Each partition block includes a base and an upper protrusion. The upper protrusion is integrally formed on the top of the base. The base has two flat sides. The upper protrusion has two smooth curved surfaces and its area gradually decreases from the bottom to the top.

[0016] Furthermore, a U-shaped notch is provided on the front outer wall of the base, and a placement opening communicating with the U-shaped notch is provided at the bottom of the base. A receiving box is movably installed in the placement opening, and a handle is fixedly installed on both outer walls of the receiving box.

[0017] To address the above problems, the present invention also provides a method for testing the bearing capacity of concrete structures, comprising the following steps:

[0018] T1: Clean the surface impurities and residues of the cubic concrete sample, and then place the sample between the four L-shaped positioning blocks of the lower steel pad.

[0019] T2: The horizontal position of the lower steel pad is accurately determined by two sets of position correction mechanisms;

[0020] T3: Control the hydraulic pressure application mechanism to apply a small pre-pressure to the sample and maintain it for a moment. During this period, observe whether the pressure value is stable through the hydraulic station display screen. Then, clear the pressure value to zero on the hydraulic station operation interface to prepare for formal testing.

[0021] T4: The hydraulic pressure application mechanism is controlled to apply axial pressure according to the loading rate set in the specification, and the pressure data is recorded in real time during the process;

[0022] T5: When the sample completely fractures, it is determined that the sample has reached its ultimate load-bearing state. At this time, pressurization should be stopped immediately, and the hydraulic pressurization mechanism should be controlled to return to its original position.

[0023] Compared with related technologies, the concrete structure bearing capacity testing device and method provided by the present invention have the following beneficial effects:

[0024] This invention provides a concrete structure bearing capacity testing device. By setting four L-shaped positioning blocks, it can perform lateral limiting and rapid positioning of concrete samples. Combined with the position correction mechanism consisting of a hydraulic cylinder, a two-way lead screw, and a clamping block with contact rollers, it can calibrate the horizontal position of the lower steel plate from both left and right and front and back directions. This automatically aligns the lower steel plate and the sample on it, ensuring that the axial pressure is strictly transmitted vertically along the central axis of the sample. This reliably eliminates the problem of eccentric loading caused by placement deviation or force offset, thereby avoiding the additional bending moment caused by eccentric loading and improving the accuracy of concrete bearing capacity testing data.

[0025] The L-shaped positioning block is elastically supported by a return spring. Combined with the cleaning mechanism, the electric motor in the cleaning mechanism drives the lead screw to rotate, pushing the push plate to move. The unique chamfered design at the bottom of the push plate converts the horizontal thrust into downward pressure during movement, forcing the L-shaped positioning block to compress the return spring and retract into the L-shaped groove, clearing a path for cleaning. Subsequently, the push plate removes residual material from the surface of the lower steel pad, solving the problems of low efficiency and safety hazards associated with manual cleaning in traditional equipment.

[0026] Two sets of symmetrical pushing mechanisms were designed to automatically clean and collect a large amount of sample residue that has fallen onto the base. When the output end of the hydraulic cylinder three of the pushing mechanism retracts, it drives the "retractable push plate" composed of push plate two and push plate three to move forward. Push plate three can adaptively retract when it encounters obstacles such as the lower ball joint support and the partition block. After bypassing the obstacle, it is reset under the action of the reset spring two, ensuring that there are no dead corners in the cleaning. It can scrape off most of the debris on the top surface of the base. The pushed debris finally falls into the front pull-out receiving box, realizing the centralized collection and processing of debris, avoiding the accumulation of debris inside the equipment, and further improving the convenience of debris cleaning.

[0027] This invention provides a method for testing the bearing capacity of concrete structures. This method, through precise sample positioning and lower steel plate calibration, combined with the adaptive pressure transmission between the ball joint support and the steel plate during the compression process, can effectively avoid eccentric loading problems, improve the accuracy of test data, and ensure the reliability and standardization of the test. Attached Figure Description

[0028] Figure 1A three-dimensional structural schematic diagram of the concrete structure bearing capacity testing device provided by the present invention;

[0029] Figure 2 for Figure 1 The front view of the concrete structure bearing capacity testing device shown.

[0030] Figure 3 for Figure 2 A schematic diagram of the three-dimensional structure of part AA shown;

[0031] Figure 4 for Figure 1 A three-dimensional structural schematic diagram of the concrete structure bearing capacity testing device from another perspective.

[0032] Figure 5 for Figure 1 The diagram shows a three-dimensional structure of the lower ball joint support and the lower steel pad in a separated state.

[0033] Figure 6 for Figure 5 The diagram shows a three-dimensional structure of the lower steel pad from a bottom-up perspective.

[0034] Figure 7 for Figure 5 The top view of the lower steel pad shown;

[0035] Figure 8 for Figure 7 The diagram shows the structure of section BB.

[0036] Figure 9 for Figure 8 An enlarged schematic diagram of section X shown;

[0037] Figure 10 for Figure 5 A schematic diagram of the three-dimensional structure of the L-shaped positioning block shown;

[0038] Figure 11 for Figure 3 A three-dimensional structural diagram of the clearing mechanism shown;

[0039] Figure 12 for Figure 3 A three-dimensional structural schematic diagram of the feeding mechanism and the position correction mechanism shown;

[0040] Figure 13 for Figure 12 The diagram shows a three-dimensional structure with the transverse carrier plate and the C-shaped cover separated.

[0041] Figure 14 for Figure 13 An enlarged schematic diagram of the Y-section shown;

[0042] Figure 15 for Figure 12 The diagram shows the connection between push plate two and push plate three.

[0043] Numbering on the map:

[0044] 1. Base; 2. Protective box; 3. Hydraulic cylinder 1; 4. Lifting plate; 5. Upper ball joint support; 6. Upper steel pad; 7. Lower ball joint support; 8. Lower steel pad; 801. Limiting groove; 9. Limiting pin; 10. L-shaped positioning block; 11. Mounting cylinder; 12. Return spring 1; 13. Ear block; 14. Fixed slide rod 1; 15. Lead screw; 16. Push plate 1; 17. Electric motor 1; 8. Corrugated pipe; 19. Hydraulic cylinder II; 20. C-shaped cover; 21. Transverse transfer plate; 22. Clamping block; 23. Bidirectional lead screw; 24. Electric motor II; 25. Contact roller; 26. Fixed slide bar II; 27. Return spring II; 28. Rectangular push rod; 29. ​​Hydraulic cylinder III; 30. Connecting plate; 31. Separator block; 32. Receiving box; 33. Baffle plate; 34. Push plate II; 35. Push plate III. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] First Embodiment

[0047] Please refer to the following: Figures 1-15In the first embodiment of the present invention, a concrete structure bearing capacity testing device is proposed, comprising: a base 1 and a protective box 2 fixedly installed on the top of the base 1. A lower ball joint support 7 is fixedly installed on the top of the base 1 and located inside the protective box 2. A lower steel pad 8 is installed on the bearing plate of the lower ball joint support 7. During testing, a cubic concrete structure sample (hereinafter referred to as the sample) is placed at the center of the lower steel pad 8. A hydraulic pressure mechanism is also provided inside the protective box 2 above the lower steel pad 8. The hydraulic pressure mechanism includes a hydraulic cylinder 3, an upper ball joint support 5, a lifting plate 4, and an upper steel pad 6. Four guide columns are slidably installed on the top of the protective box 2, and the bottom ends of the four guide columns extend into the protective box 2. The lifting plate 4 is fixedly installed on the bottom ends of the four guide columns. The hydraulic cylinder 3 is fixedly installed on the top of the protective box 2, and its output end extends into the protective box 2 and is connected to the lifting plate 4. The upper ball joint support 5 is fixedly installed on the bottom of the lifting plate 4. The upper steel pad 6 is installed on the upper ball joint support 7. Four limiting pins 9 are fixedly installed on the bearing plate of the hinge support 5 and the bearing plate of the lower ball hinge support 7. Four limiting circular grooves 801 are opened at the bottom of the lower steel pad 8. The four limiting pins 9 are respectively located in the four limiting circular grooves 801, and the diameter of the limiting pins 9 is smaller than the diameter of the limiting circular grooves 801. After assembly, an annular gap is formed between the two. The annular gap width is maintained at 0.5~2mm. When axial pressure is applied to the sample, the concrete sample may undergo slight deformation or tilting due to its own material properties. At this time, the lower steel pad 8 rotates slightly, which can keep the lower steel pad 8 in contact with the deformation trend of the bottom surface of the sample, avoid point contact between the pad and the sample due to local deformation of the sample, ensure that the pressure is always transmitted in the vertical direction, and the axial pressure is always uniformly applied to the entire cross section of the sample, eliminate local stress concentration, and ensure the accuracy of the load-bearing capacity test data. At the same time, the cooperation between the limiting pins 9 and the limiting circular grooves 801 can limit the lower steel pad 8 from excessive lateral displacement, and ensure that the sample is always in the central area of ​​the lower steel pad 8.

[0048] Four L-shaped positioning blocks 10 are installed in the middle area of ​​the top of the lower steel pad 8, and the four L-shaped positioning blocks 10 together form a square area. The center of this square area coincides with the center of the lower steel pad 8. Before testing, the sample is placed in the square area between the four L-shaped positioning blocks 10. Through the lateral limiting effect of the four L-shaped positioning blocks 10, the initial centering of the sample can be quickly achieved. This ensures that the sample axis is consistent with the force center of the lower steel pad 8, thereby ensuring that the axial pressure is always transmitted along the central axis of the sample during the testing process.

[0049] Ear blocks 13 are fixedly installed on both outer walls of the lower steel pad 8. Two sets of position correction mechanisms are set inside the protective box 2. The two sets of position correction mechanisms are symmetrically distributed on both sides of the lower steel pad 8. The two sets of position correction mechanisms are used to cooperate with the ear blocks 13 to accurately locate the horizontal plane position of the lower steel pad 8. When the position of the lower steel pad 8 is accurately located, the sample can also be accurately located after being placed in the positioning area between the four L-shaped positioning blocks 10, so as to avoid axial pressure bias caused by deviation during testing and further ensure the uniformity of the sample stress.

[0050] Specifically, each set of position correction mechanisms includes a second hydraulic cylinder 19, a transverse transfer plate 21, two clamping blocks 22, a double-acting lead screw 23, and a second electric motor 24. The transverse transfer plate 21 is located on one side of the lower steel pad 8. The second hydraulic cylinder 19 is fixedly installed on one side of the outer wall of the protective box 2. The output end of the second hydraulic cylinder 19 extends into the protective box 2 and is fixedly installed with a C-shaped cover 20. The C-shaped cover 20 is fixedly connected to the transverse transfer plate 21. Two limiting slides are opened on the transverse transfer plate 21. The two clamping blocks 22 are slidably installed in the corresponding limiting slides. Specifically, a sliding block is integrally formed on the clamping block 22. The sliding block is located in The corresponding limiting slide is slidably connected to the inner wall of the corresponding limiting slide. The corresponding ear block 13 is located between two clamping blocks 22. Multiple contact rollers 25 are rotatably installed on the outer wall of the clamping block 22 near the lower steel pad 8, and the multiple contact rollers 25 are arranged at equal intervals. The bidirectional screw 23 is rotatably installed on the transverse transfer plate 21. The bidirectional screw 23 is located inside the C-shaped cover 20. The bidirectional screw 23 is threaded to the two clamping blocks 22 through two sections of external threads with opposite directions on the surface wall. The electric motor 24 is fixedly installed on the transverse transfer plate 21. The output end of the electric motor 24 is fixedly connected to one end of the corresponding bidirectional screw 23. Next, when it is necessary to correct the horizontal position of the lower steel pad 8, the output ends of the hydraulic cylinders 19 in the two sets of position correction mechanisms are activated to extend synchronously, pushing the transverse carrier plates 21 on both sides to move horizontally towards the lower steel pad 8 (the moving speed is kept consistent). As the transverse carrier plates 21 move, the clamping blocks 22 installed on the carrier plates gradually approach the lower steel pad 8 until the contact rollers 25 on the clamping blocks 22 contact the side wall of the lower steel pad 8. At this time, the clamping blocks 22 on both sides form symmetrical lateral constraints on the lower steel pad 8. Under the synchronous thrust from both sides, the lower steel pad 8 automatically adjusts to the left-right center position of the protective box 2; left-right position After calibration, start the electric motor 24 to drive the bidirectional lead screw 23 to rotate in the forward direction. Driven by the bidirectional lead screw 23, the two clamping blocks 22 will move synchronously towards each other along the limiting slide of the transverse carrier plate 21, gradually approaching the front and rear sides of the ear block 13. The ear block 13 is restricted to the central position between the two clamping blocks 22, completing the precise positioning of the front and rear positions of the lower steel pad 8. The contact roller 25 makes rolling contact with the left and right side walls of the lower steel pad 8. When the clamping blocks 22 clamp the ear block 13, the contact roller 25 and the lower steel pad 8 generate rolling friction during the movement, which can effectively reduce the running resistance of the clamping blocks 22.

[0051] In this embodiment, the top of the lower steel pad 8 is provided with four L-shaped grooves, and four L-shaped positioning blocks 10 are slidably installed in the four L-shaped grooves respectively. At the bottom of the lower steel pad 8, corresponding to the position of each L-shaped positioning block 10, four mounting cylinders 11 are threadedly installed. Each of the four mounting cylinders 11 is provided with a return spring 12. The top end of the return spring 12 contacts the bottom of the L-shaped positioning block 10, and the bottom end contacts the inner wall of the bottom of the mounting cylinder 11. A cleaning mechanism is provided inside the protective box 2 to clean the concrete sample residue (concrete fragments, powder) on the top of the lower steel pad 8. Under the elastic force of the return spring 12, the top of the L-shaped positioning block 10 protrudes from the lower steel pad 8, ensuring the sample can be positioned. Under pressure, it can retract downwards into the L-shaped groove. The cleaning mechanism specifically includes two fixed sliding rods 14, a lead screw 15, a push plate 16, and an electric motor 17. The slide rods 14 are all fixedly installed in the rear position inside the protective box 2. The push plate 16 is slidably sleeved on the two fixed slide rods 14. The lead screw 15 is rotatably installed inside the protective box 2. The lead screw 15 passes through the push plate 16 and is threadedly connected to the push plate 16. The electric motor 17 is fixedly installed on one side of the outer wall of the protective box 2. One end of the lead screw 15 extends to the outside of the protective box 2 and is fixedly connected to the output end of the electric motor 17. The bottom of the push plate 16 and the connection between the left and right outer walls are all chamfered. When cleaning the platform, the push plate 16 moves towards the L-shaped positioning block 10. Its corresponding chamfered surface can convert the horizontal thrust into vertical downward pressure, pushing the L-shaped positioning block 10 down along the vertical section of the slide groove, avoiding the L-shaped positioning block 10 from obstructing the movement of the push plate 16. In the initial state, the push plate 16 is located on the left or right side of the lower ball joint support 7, and will not obstruct the placement of the sample or the pressure action of the hydraulic pressure mechanism.

[0052] In this embodiment, in order to isolate and protect the fixed slide rod 14 and the lead screw 15, a bellows 18 is movably sleeved on both fixed slide rod 14 and lead screw 15. One end of the bellows 18 is fixedly connected to the push plate 16, and the other end is fixedly connected to the inner wall of the corresponding protective box 2. The bellows 18 is made of oil-resistant and wear-resistant nitrile rubber and can extend and retract freely.

[0053] In this embodiment, two sets of pushing mechanisms are symmetrically arranged inside the protective box 2, which are used to push the concrete sample residue inside the protective box 2 and located at the top of the base 1 to the outside of the protective box 2, so as to achieve thorough cleaning and centralized collection of the residue.

[0054] Each set of pushing mechanisms includes a second push plate 34, a third push plate 35, a rectangular push rod 28, and a third hydraulic cylinder 29. The second push plate 34 is housed inside the protective box 2. The outer walls of the two push plates 34, located away from each other, are respectively attached to the left and right inner walls of the protective box 2. The third push plate 35 is slidably mounted on the second push plate 34. The second push plate 34 and the third push plate 35 constitute a "retractable push plate," which can extend and retract laterally. When it contacts the base of the separator block 31 mentioned below, the third push plate 35 retracts into the second push plate 34. The end face of the third push plate 35 away from the rectangular push rod 28 is an arc surface. The bottoms of both the second push plate 34 and the third push plate 35 are in contact with the top of the base 1. Two fixed sliding rods 26 are fixedly installed on the second push plate 34, and both fixed sliding rods 26 penetrate... Push plate 35 is slidably connected to push plate 35. A return spring 27 is fitted on fixed slide rod 26. One end of return spring 27 is fixedly connected to push plate 35, and the other end is fixedly connected to push plate 24. When push plate 35 retracts, return spring 27 is compressed, storing elastic potential energy. When push plate 35 loses external resistance, it returns to its original position under the elastic force of return spring 27. Rectangular push rod 28 is slidably installed on the rear outer wall of protective box 2. One end of rectangular push rod 28 extends into protective box 2 and is fixedly connected to push plate 24. Hydraulic cylinder 39 is fixedly installed on the top of base 1 and located on one side of protective box 2. A connecting plate 30 is fixedly connected to the output end of hydraulic cylinder 39. The connecting plate 30 and the rectangular push rod 29 are connected to the rear outer wall of protective box 2. The rectangular push rod 28 is fixedly connected to one end outside the protective box 2. Separator blocks 31 are fixedly installed on both the front and rear sides of the lower ball joint support 7. Each separator block 31 includes a base and an upper protrusion. The upper protrusion is integrally formed and located on the top of the base. The base is approximately triangular, with two flat sides tangent to the circular outer shell of the lower ball joint support 7. The upper protrusion gradually decreases in area from bottom to top, having two smooth curved surfaces. After some sample fragments fall to the top of the upper protrusion, they slide down the two smooth curved surfaces to the left and right sides of the separator block 31. During the retraction of the output end of the hydraulic cylinder 29, the rectangular push rod 28 moves forward via the connecting plate 30. The rectangular push rod 28 pushes the push plate 34 forward, causing the "retractable push plate" to move forward. The debris on the top of the base 1 moves forward. The arc-shaped end of the push plate 35 first abuts against the flat side of the base of the rear partition block 31, then against the circular shell of the lower ball joint support 7, and finally against the flat side of the base of the front partition block 31. Throughout the process, the "retractable push plate" can adaptively extend and retract according to the width of the moving path, which can clean up the debris more thoroughly. A baffle plate 33 is also fixedly installed on the rear inner wall of the protective box 2. The baffle plate 33 is inclined to prevent most of the debris from falling into the rear of the "retractable push plate". Multiple discharge ports are also opened on the rear outer wall of the protective box 2. If a small amount of debris falls into the rear of the "retractable push plate", it can be cleaned periodically through the discharge ports.

[0055] In this embodiment, in order to facilitate the centralized collection of sample fragments pushed out of the protective box 2, a U-shaped notch is provided on the front outer wall of the base 1, and a placement opening connected to the U-shaped notch is provided at the bottom of the base 1. A receiving box 32 is movably installed in the placement opening, and a handle is fixedly installed on both outer walls of the receiving box 32. The receiving box 32 can be pulled out by the handle, and then the fragments can be poured out.

[0056] In this embodiment:

[0057] First, place the cubic concrete sample in the center of the lower steel pad 8, so that it is within the square area enclosed by the four L-shaped positioning blocks 10. Under the elastic force of the return spring 12, the upper part of the L-shaped positioning block 10 protrudes from the top surface of the lower steel pad 8, thereby achieving lateral positioning of the sample and ensuring that the sample axis is aligned with the force center of the lower steel pad 8.

[0058] Subsequently, the position correction mechanism is activated to precisely calibrate the horizontal position of the lower steel pad 8. The two hydraulic cylinders 19 work synchronously to push the transverse carrier plate 21 towards the center, so that the contact rollers 25 on the clamping blocks 22 contact the outer walls on both sides of the lower steel pad 8, forming a symmetrical lateral constraint on the lower steel pad 8, achieving the centering positioning of the lower steel pad 8 in the left and right directions. Then, the electric motor 24 is activated to drive the bidirectional lead screw 23 to rotate in the forward direction, causing the two clamping blocks 22 to move towards each other, clamping the ear block 13 from the front and back directions, further calibrating the front and back position of the lower steel pad 8, ensuring that the sample is in a completely centered state. The design of the contact rollers 25 effectively reduces frictional resistance, making the position adjustment more stable and accurate.

[0059] After the position calibration is completed, the output end of the hydraulic cylinder 3 extends downward, pushing the lifting plate 4 down along the guide slide column, which in turn moves the upper ball joint support 5 and the upper steel pad 6 downward until the upper steel pad 6 is in full contact with the top surface of the sample. Then, the axial pressure is gradually increased on the sample according to the preset loading rate. During the application of axial pressure, the concrete sample may undergo slight deformation or tilting. At this time, the ball core of the upper ball joint support 5 rotates slightly in the ball cup to compensate for this, driving the upper steel pad 6 to automatically adjust its angle so that it always maintains full-area contact with the deformed top surface of the sample. Similarly, if the bottom of the sample deforms due to crushing, the lower steel pad 8 can adaptively rotate slightly based on the lower ball joint support 7 to follow the deformation trend of the bottom surface of the sample, ensuring that the axial pressure is always perpendicular to the sample contact surface and evenly distributed across its entire cross-section, avoiding stress concentration. Meanwhile, the limiting groove 801 at the bottom of the lower steel pad 8 cooperates with the limiting pin 9, which allows the steel pad to deflect slightly while limiting its excessive horizontal displacement, ensuring that the alignment of the sample with the pressure center line is always within the allowable error range.

[0060] After the test is completed, hydraulic cylinder 3 returns, and the upper steel pad 6 rises away from the sample. At this time, the electric motor 17 of the cleaning mechanism is started, driving the lead screw 15 to rotate. Under the helical push of the lead screw 15, the push plate 16 will move left or right along the fixed slide rod 14. When passing the lower steel pad 8, the chamfered surface at the bottom of the push plate 16 will press down on the L-shaped positioning block 10 during the movement, causing it to overcome the elastic force of the return spring 12 and retract into the L-shaped slide groove to avoid interfering with the cleaning action. The push plate 16 continues to move forward, pushing the concrete debris on the top of the lower steel pad 8 forward. The concrete debris on the steel pad 8 will fall onto the base 1. Then, the sample debris on the base 1 will be pushed out of the protective box 2 by two sets of pushing mechanisms. The output ends of the two hydraulic cylinders 29 will retract, and the "telescopic push plate" composed of push plate 34 and push plate 35 will move forward through the connecting plate 30 and the rectangular push rod 28. During the movement, the arc end of push plate 35 will contact the rear partition block 31, the outer shell of the lower ball joint support 7 and the front partition block 31 in turn. It will expand and contract adaptively according to the base spacing to ensure that the debris is completely pushed into the receiving box 32 on the front side of the protective box 2.

[0061] Second embodiment:

[0062] In a second embodiment of the present invention, a method for detecting the bearing capacity of a concrete structure is provided, comprising the following steps:

[0063] T1: Clean the surface impurities and residues of the cubic concrete sample, and then place the sample between the four L-shaped positioning blocks 10 of the lower steel pad 8.

[0064] T2: The horizontal position of the lower steel pad 8 is accurately located by two sets of position correction mechanisms;

[0065] T3: Control the hydraulic pressure application mechanism to apply a small pre-pressure to the sample and maintain it for a moment. During this period, observe whether the pressure value is stable through the hydraulic station display screen. Then, clear the pressure value to zero on the hydraulic station operation interface to prepare for formal testing.

[0066] T4: The hydraulic pressure application mechanism is controlled to apply axial pressure according to the loading rate set in the specification, and the pressure data is recorded in real time during the process;

[0067] T5: When the sample completely fractures, it is determined that the sample has reached its ultimate load-bearing state. At this time, pressurization should be stopped immediately, and the hydraulic pressurization mechanism should be controlled to return to its original position.

[0068] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A concrete structure bearing capacity testing device, comprising a base and a protective box fixedly installed on the top of the base, wherein a lower ball joint support is fixedly installed on the top of the base and located inside the protective box, a lower steel pad is installed on the bearing plate of the lower ball joint support, and a hydraulic pressure applying mechanism is also provided inside the protective box above the lower steel pad, characterized in that, Four limiting pins are fixedly installed on the bearing plate of the lower ball joint support, and four limiting circular grooves are opened at the bottom of the lower steel pad. The four limiting pins are respectively located in the four limiting circular grooves, and the diameter of the limiting pins is smaller than the diameter of the limiting circular grooves. Four L-shaped positioning blocks are installed in the middle area of ​​the top of the lower steel pad, and the four L-shaped positioning blocks together form a square area, the center of which coincides with the center of the lower steel pad. Ear blocks are fixedly installed on both outer walls of the lower steel pad. Two sets of position correction mechanisms are provided inside the protective box. The two sets of position correction mechanisms are used to cooperate with the ear blocks to accurately locate the horizontal plane position of the lower steel pad.

2. The concrete structure bearing capacity testing device according to claim 1, characterized in that, Each set of the position correction mechanisms includes a second hydraulic cylinder, a transverse transfer plate, two clamping blocks, a double-acting screw, and a second electric motor. The transverse transfer plate is disposed on one side of the lower steel pad. The second hydraulic cylinder is fixedly installed on the outer wall of one side of the protective box. The output end of the second hydraulic cylinder extends into the protective box and is fixedly connected to the transverse transfer plate. The two clamping blocks are slidably installed on the transverse transfer plate, and the corresponding lugs are located between the two clamping blocks. The double-acting screw is rotatably installed on the transverse transfer plate and is threadedly connected to the two clamping blocks respectively. The second electric motor is fixedly installed on the transverse transfer plate, and the output end of the second electric motor is fixedly connected to one end of the corresponding double-acting screw.

3. The concrete structure bearing capacity testing device according to claim 2, characterized in that, Multiple contact rollers are rotatably mounted on the outer wall of the clamping block near the lower steel pad, and the multiple contact rollers are arranged at equal intervals.

4. The concrete structure bearing capacity testing device according to claim 1, characterized in that, The top of the lower steel pad has four L-shaped grooves, and the four L-shaped positioning blocks are slidably installed in the four L-shaped grooves respectively. The bottom of the lower steel pad is threaded with four mounting cylinders, and each of the four mounting cylinders is equipped with a return spring. The top end of the return spring contacts the bottom of the L-shaped positioning block, and the bottom end contacts the bottom inner wall of the mounting cylinder. The protective box is equipped with a cleaning mechanism for cleaning the concrete sample residue on the top of the lower steel pad.

5. The concrete structure bearing capacity testing device according to claim 4, characterized in that, The platform clearing mechanism includes two fixed slide rods, a lead screw, a push plate, and an electric motor. The two fixed slide rods are fixedly installed inside the protective box. The push plate is slidably sleeved on the two fixed slide rods. The lead screw is rotatably installed inside the protective box, passes through the push plate, and is threadedly connected to the push plate. The electric motor is fixedly installed on one outer wall of the protective box. One end of the lead screw extends outside the protective box and is fixedly connected to the output end of the electric motor. The bottom of the push plate and the connection between it and the left and right outer walls are all chamfered.

6. The concrete structure bearing capacity testing device according to claim 5, characterized in that, Both of the fixed sliding rods and the lead screw are movably fitted with corrugated tubes. One end of the corrugated tube is fixedly connected to the push plate, and the other end is fixedly connected to the inner wall of the corresponding protective box.

7. The concrete structure bearing capacity testing device according to claim 5, characterized in that, The protective box is also symmetrically equipped with two sets of pushing mechanisms, which are used to push the concrete sample residue inside the protective box and located at the top of the base to the outside of the protective box. Each set of the pushing mechanism includes a second pusher plate, a third pusher plate, a rectangular pusher rod, and a third hydraulic cylinder. The second pusher plate is disposed inside the protective box, and the third pusher plate is slidably mounted on the second pusher plate. The bottoms of both the second and third pusher plates are in contact with the top of the base. Two fixed sliding rods are fixedly mounted on the second pusher plate, both of which pass through the third pusher plate and are slidably connected to the third pusher plate. A return spring is sleeved on the second fixed sliding rod, one end of which is fixedly connected to the third pusher plate and the other end of which is fixedly connected to the second pusher plate. The rectangular pusher rod is slidably mounted on the rear outer wall of the protective box, one end of which extends into the protective box and is fixedly connected to the second pusher plate. The third hydraulic cylinder is fixedly mounted on the top of the base and located on one side of the protective box. The output end of the third hydraulic cylinder is fixedly connected to the end of the rectangular pusher rod located outside the protective box.

8. The concrete structure bearing capacity testing device according to claim 7, characterized in that, The lower ball joint support has partition blocks fixedly installed on both the front and rear sides. Each partition block includes a base and an upper protrusion. The upper protrusion is integrally formed on the top of the base. The base has two flat sides. The upper protrusion has two smooth curved surfaces and its area gradually decreases from the bottom to the top.

9. The concrete structure bearing capacity testing device according to claim 7, characterized in that, A U-shaped notch is provided on the front outer wall of the base, and a placement opening is provided at the bottom of the base that communicates with the U-shaped notch. A receiving box is movably installed in the placement opening, and a handle is fixedly installed on both outer walls of the receiving box.

10. A method for testing the bearing capacity of concrete structures, characterized in that, The concrete structure bearing capacity testing device as described in any one of claims 1-9 is used for testing, including the following steps: T1: Clean the surface impurities and residues of the cubic concrete sample, and then place the sample between the four L-shaped positioning blocks of the lower steel pad. T2: The horizontal position of the lower steel pad is accurately determined by two sets of position correction mechanisms; T3: Control the hydraulic pressure application mechanism to apply a small pre-pressure to the sample and maintain it for a moment. During this period, observe whether the pressure value is stable through the hydraulic station display screen. Then, clear the pressure value to zero on the hydraulic station operation interface to prepare for formal testing. T4: The hydraulic pressure application mechanism is controlled to apply axial pressure according to the loading rate set in the specification, and the pressure data is recorded in real time during the process; T5: When the sample completely fractures, it is determined that the sample has reached its ultimate load-bearing state. At this time, pressurization should be stopped immediately, and the hydraulic pressurization mechanism should be controlled to return to its original position.

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