A concrete void measuring device

Abstract

This invention discloses a concrete void measuring device, relating to the field of concrete void measuring technology. It includes a measuring platform, with a suspended balance base fixedly installed on the left side of the upper surface of the measuring platform. A second balance frame is installed on the upper surface of the suspended balance base, and a second hook is fixedly installed on the lower surface of the second balance frame. A second connecting line is installed on the second hook, and a second hanging basket is fixedly installed at one end of the second connecting line. A water tank is provided inside the measuring platform, and a downward-moving mechanism is installed on the side of the second hanging basket. By setting the downward-moving mechanism and the reciprocating mechanism, during the process of the second hanging basket lowering the specimen, a fixed rack meshes with a large gear to drive a small gear to rotate, thereby driving a cam to push a roller, an L-shaped frame, a vertical frame, and a moving plate to achieve intermittent reciprocating motion. Before the specimen enters the water, it actively and intermittently slaps the water surface, effectively disrupting the formation conditions of the meniscus water film.

Description

Technical Field

[0001] This invention relates to the field of concrete void measurement technology, specifically to a concrete void measurement device. Background Technology

[0002] Concrete is an artificial stone material made by mixing cementitious materials, aggregates, water and admixtures in a certain proportion and then hardening it. Its internal structure is complex, containing solid, liquid and gas phases. Among them, pores are the key microstructure that affects the strength, durability and volume stability of concrete. The main methods for measuring concrete pores include mercury intrusion porosimetry (to measure pore size distribution), nitrogen adsorption method (to measure micropores and mesopores), and underwater weighing method (to measure open porosity).

[0003] The existing underwater weighing method involves drying concrete specimens in an oven to constant weight, then cooling them to room temperature in a desiccator and weighing them. The specimens are then completely submerged in water, and their suspended weight in the water is measured. Next, the specimens are removed from the water, and surface water is gently wiped away with a damp towel until they are saturated and dry. Their saturated surface-dry weight is immediately measured. The open porosity of the concrete is then calculated using a formula based on the dry weight, the weight in water, and the saturated surface-dry weight.

[0004] However, during the operation, when the specimen is lifted from the water to the point where it is about to be taken out of the water or just immersed, a meniscus will form between the water surface and the suspension line or the surface of the specimen. This water film can generate tens or even hundreds of milligrams of false tension, and the degree of damage to the water film varies after each lift, resulting in unstable repeated weighing. It is not possible to break the tension of the water surface before entering the water, which will reduce the reliability and comparability of the test data.

[0005] Although it is possible to disrupt the surface tension of the water before it enters the water, the disruption will continue during the process and cannot be done intermittently. The continuous disturbance will cause the water surface to generate constantly changing ripples and turbulence, resulting in dynamic and non-periodic additional force fluctuations when the specimen passes through the water surface due to the uneven water layer thickness and surface tension. This is not conducive to more efficient operation and use in practice. Summary of the Invention

[0006] The purpose of this invention is to provide a concrete void measurement device to solve the problem of damage to the surface tension of the water before the specimen is immersed in water, and to avoid continuous damage.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a concrete void measuring device, comprising a measuring platform, a suspended balance base fixedly installed on the left side of the upper surface of the measuring platform, a second balance frame installed on the upper surface of the suspended balance base, a second hook fixedly installed on the lower surface of the second balance frame, a second connecting line installed on the second hook, a second hanging basket fixedly installed at one end of the second connecting line, a water tank opened inside the measuring platform, a downward moving mechanism installed on the side of the second hanging basket, and a reciprocating moving mechanism for converting meshing rotational power into reciprocating force installed at the power output end of the downward moving mechanism.

[0008] Preferably, the downward actuation mechanism includes a fixed rack, a rectangular bar, a first rotating rod, a large gear, a small gear, and a second rotating rod. The left side of the fixed rack is fixedly installed with the right side of the second hanging basket. The outer surface of the large gear meshes with the right side of the fixed rack. The outer surface of the first rotating rod is fixedly installed with the inside of the large gear. The inner wall of the rectangular bar is rotatably installed with the outer surface of one end of the first rotating rod. The outer surface of the small gear meshes with the outer surface of the large gear. The outer surface of the second rotating rod is fixedly installed with the inside of the small gear.

[0009] Preferably, the reciprocating actuation mechanism includes a fixed block, a connecting spring, a telescopic rod, an L-shaped frame, a vertical frame, and an actuating plate. The right side of the fixed block is fixedly installed to the left side inside the water tank. One end of the connecting spring is fixedly installed to the bottom of the fixed block. One end of the telescopic rod is fixedly installed to the bottom of the fixed block. The upper surface of the L-shaped frame is fixedly installed to the other end of the connecting spring and the telescopic rod. The upper surface of the vertical frame is fixedly installed to the lower surface of the L-shaped frame. The upper surface of the actuating plate is fixedly installed to the lower surface of the vertical frame.

[0010] Preferably, the right side of the rectangular bar is fixedly installed to the left side inside the water tank, and the outer surface of the rotating rod is rotatably installed to the inner wall of the rectangular bar.

[0011] Preferably, a cam is fixedly mounted on the outer surface of the rectangular strip, and a roller is attached to the outer surface of the cam.

[0012] Preferably, the bottom of the roller housing is fixedly installed on the upper surface of the L-shaped frame.

[0013] Preferably, a balancing frame is installed on the left side of the suspended balance base, and a hook is fixedly installed at the bottom of the balancing frame.

[0014] Preferably, a connecting line is installed on the surface of the hook, a hanging basket is installed at the bottom end of the connecting line, and a counterweight is fixedly installed inside the hanging basket.

[0015] Preferably, the measuring platform has an observation window installed on its front side.

[0016] Preferably, the second hanging basket uses a test specimen placed inside to drive a fixed rack to move downwards and mesh with a large gear, thereby enabling the test specimen to enter the water and disrupt the surface tension of the water.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention, by setting up a downward moving mechanism and a reciprocating moving mechanism, allows the fixed rack to mesh with the large gear and drive the small gear to rotate during the descent of the specimen in the hanging basket. This, in turn, drives the cam to push the roller, L-shaped frame, vertical frame, and moving plate to achieve intermittent reciprocating motion. Before the specimen enters the water, it actively and intermittently pats the water surface, effectively disrupting the formation conditions of the meniscus water film. This avoids the problem of false tens or even hundreds of milligrams of tension caused by water surface tension in the prior art, and prevents microbubbles from adhering to the specimen surface. As a result, it improves the repeatability and stability of the weighing reading in water, ensures that the calculation benchmark of the difference between the dry weight and the weight in water is consistent, and enhances the reliability and comparability of the open porosity measurement results.

[0018] This invention utilizes the meshing transmission between a fixed rack and pinion, and the reciprocating motion achieved through the cooperation of a cam, roller, connecting spring, and telescopic rod. It requires no electronic sensors or external power source; the water surface tension breaking operation is automatically triggered solely by the specimen's descent. A rectangular bar is fixedly installed inside the water tank, providing stable support for rotating rods one and two. The overall structure is compact, has a low failure rate, and is easy to maintain. A balancing system consisting of a balance frame, hook, connecting line, hanging basket, and counterweight maintains the overall balance of the device. An observation window facilitates real-time monitoring of the water tank's internal conditions, enabling operators to efficiently measure concrete porosity. This invention is suitable for accurate detection of low porosity in high-density concrete on-site. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 For the present invention Figure 1 A schematic diagram of the side view structure; Figure 3 For the present invention Figure 1 A top-view structural diagram; Figure 4 For the present invention Figure 1 Internal structure diagram; Figure 5 For the present invention Figure 1 Schematic diagram of the cross-section and top view of the structure; Figure 6 For the present invention Figure 5 Enlarged schematic diagram of the structure at point A; Figure 7 For the present invention Figure 5 A schematic diagram of the side view structure; Figure 8 For the present invention Figure 7 Enlarged schematic diagram of the structure at point B.

[0020] In the diagram: 1. Measuring platform; 2. Suspended balance base; 3. Balance frame one; 4. Hook one; 5. Connecting line one; 6. Hanging basket one; 7. Counterweight; 8. Observation window; 9. Water tank; 10. Balance frame two; 11. Hook two; 12. Connecting line two; 13. Hanging basket two; 14. Downward moving mechanism; 141. Fixed rack; 142. Rectangular bar; 143. Rotating rod one; 144. Large gear; 145. Small gear; 146. Rotating rod two; 15. Reciprocating moving mechanism; 151. Fixed block; 152. Connecting spring; 153. Telescopic rod; 154. L-shaped frame; 155. Roller; 156. Cam; 157. Vertical frame; 158. Moving plate. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1 , Figure 5 and Figure 6As shown, the present invention provides a technical solution: a concrete void measuring device, including a measuring platform 1, a suspended balance base 2 fixedly installed on the left side of the upper surface of the measuring platform 1, a balance frame 2 10 installed on the upper surface of the suspended balance base 2, a hook 2 11 fixedly installed on the lower surface of the balance frame 2 10, a connecting line 2 12 installed on the hook 2 11, a hanging basket 2 13 fixedly installed at one end of the connecting line 2 12, a water tank 9 opened inside the measuring platform 1, a downward moving mechanism 14 installed on the side of the hanging basket 2 13, a reciprocating moving mechanism 15 that converts the meshing rotational force into reciprocating force installed at the power output end of the downward moving mechanism 14, the downward moving mechanism 14 including a fixed rack 141, a rectangular bar 142, a rotating rod 143, and a large gear 144. The small gear 145 and the rotating rod 146 are fixedly installed on the left side of the fixed rack 141 and the right side of the hanging basket 13. The outer surface of the large gear 144 meshes with the right side of the fixed rack 141. The outer surface of the rotating rod 143 is fixedly installed with the inside of the large gear 144. The inner wall of the rectangular bar 142 is rotatably installed with the outer surface of one end of the rotating rod 143. The outer surface of the small gear 145 meshes with the outer surface of the large gear 144. The outer surface of the rotating rod 146 is fixedly installed with the inside of the small gear 145. The right side of the rectangular bar 142 is fixedly installed with the left side of the inside of the water tank 9. The outer surface of the rotating rod 146 is rotatably installed with the inner wall of the rectangular bar 142. A cam 156 is fixedly installed on the outer surface of the rectangular bar 142. A roller 155 is attached to the outer surface of the cam 156.

[0023] Specifically, the downward-moving mechanism 14 and the reciprocating mechanism 15 cooperate to achieve efficient power conversion and transmission. In the downward-moving mechanism 14, the fixed rack 141 meshes with the large gear 144, which in turn meshes with the small gear 145. This multi-stage gear transmission structure can rationally distribute and reduce the power of the downward movement of the second hanging basket 13. When the second hanging basket 13 moves downward, it drives the fixed rack 141 to move, which in turn drives the large gear 144 and the small gear 145 to rotate, providing a stable and suitable power input for subsequent power conversion. As the pinion 145 drives the rotating rod 146 to rotate, the cam 156 fixed on the rectangular bar 142 also rotates accordingly. The special contour curve of the cam 156 drives the roller 155 to reciprocate. This reciprocating force can simulate the periodic external force acting on the concrete void drainage process, more realistically reflecting the actual situation and making the measurement results more scientific and accurate.

[0024] according to Figure 1 , Figure 7 and Figure 8As shown, the reciprocating actuation mechanism 15 includes a fixed block 151, a connecting spring 152, a telescopic rod 153, an L-shaped frame 154, a vertical frame 157, and an actuating piece 158. The right side of the fixed block 151 is fixedly installed inside the water tank 9 on the left side. One end of the connecting spring 152 is fixedly installed to the bottom of the fixed block 151. One end of the telescopic rod 153 is fixedly installed to the bottom of the fixed block 151. The upper surface of the L-shaped frame 154 is fixedly installed to the other ends of the connecting spring 152 and the telescopic rod 153. The upper surface of the vertical frame 157 is fixedly installed to the lower surface of the L-shaped frame 154. The upper surface of the actuating piece 158 is fixedly installed to the lower surface of the vertical frame 157. The bottom of the outer shell of the roller 155 is fixedly installed to the upper surface of the L-shaped frame 154.

[0025] Specifically, the reciprocating mechanism 15, through the coordinated operation of its components, precisely converts the power generated by the interaction between the cam 156 and the roller 155 into an effective reciprocating motion. When the roller 155 moves up and down under the action of the cam 156, it drives the connected L-shaped frame 154 to move synchronously. Due to the connection between the connecting spring 152 and the telescopic rod 153, the movement of the L-shaped frame 154 is smoother and more regular, which in turn drives the actuating plate 158 to perform precise reciprocating motion via the vertical frame 157. This accurately simulates the periodic external forces experienced during the drainage process of concrete voids, improving the scientific validity and accuracy of the measurement results. The connecting spring 152 and the telescopic rod 153 play a crucial role in buffering and resetting. When the L-shaped frame 154 is driven upward by the roller 155, the connecting spring 152 is stretched, and the telescopic rod 153 extends, storing elastic potential energy. When the roller 155 continues to rotate and no longer applies an upward force to the L-shaped frame 154, the elastic potential energy of the connecting spring 152 is released, pulling the L-shaped frame 154 downward to reset, and the telescopic rod 153 also shortens accordingly, ensuring that the L-shaped frame 154 can quickly and accurately return to its initial position, preparing for the next reciprocating motion, making the entire reciprocating motion process smoother and more stable, and reducing measurement errors caused by discontinuous movements. The right side of the fixing block 151 is fixedly installed inside the water tank 9 on the left side, providing a stable support foundation for the entire reciprocating motion mechanism 15. One end of the connecting spring 152 and the telescopic rod 153 is fixed to the bottom of the fixing block 151, and the other end is connected to the L-shaped frame 154. The installation method ensures that the connection between the components is firm and reliable, and it is not easy for them to loosen or fall off during the reciprocating motion. This ensures the stability and reliability of the mechanism and is conducive to long-term stable measurement of concrete voids.

[0026] according to Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a balance frame 3 is installed on the left side of the suspended balance base 2. A hook 4 is fixedly installed at the bottom of the balance frame 3. A connecting line 5 is installed on the surface of the hook 4. A hanging basket 6 is installed at the bottom of the connecting line 5. A counterweight 7 is fixedly installed inside the hanging basket 6. An observation window 8 is installed on the front of the measuring platform 1. The hanging basket 13 moves the fixed rack 141 downward by placing the specimen inside, which meshes with the large gear 144, so that the specimen enters the water first to break the surface tension of the water.

[0027] Specifically, a balance frame 3 is installed on the left side of the suspended balance base 2, and is connected to a hanging basket 6 via a hook 4 and a connecting line 5. A counterweight 7 is fixedly installed inside the hanging basket 6, forming a dual measurement system with the second hanging basket 13. This system allows for simultaneous measurement of samples in different states or with different samples. For example, it can compare the stable weight of the counterweight 7 inside the first hanging basket with the weight change after placing the sample inside the second hanging basket 13. This allows for more accurate acquisition of various data on the void measurement process of the concrete sample, providing a more comprehensive and accurate basis for in-depth analysis of the void characteristics of concrete. An observation window 8 is installed on the front of the measuring platform 1, allowing operators to directly observe the conditions inside the hanging basket 1 6 and hanging basket 2 13, including the placement of the specimen, the drainage process, and changes in the water level. The balance frame 1 3 is fixedly installed on the left side of the suspended balance base 2, providing a stable support structure for the hanging basket 1 6, ensuring that the hanging basket 1 6 remains stable during the measurement process and reducing measurement errors caused by shaking or tilting. The reasonable layout and stable installation of the entire device create a relatively stable measurement environment for concrete void measurement, which is conducive to improving the repeatability and consistency of the measurement and making the results of different measurements comparable.

[0028] The overall mechanism achieves the following effect: Concrete specimens are placed in an oven and dried to constant weight. After removal, they are cooled to room temperature in a desiccator, and then the dried weight of the specimens is measured. The basket containing the specimens, 13, is then moved downwards again, causing the fixed rack 141, fixed to the right side of the basket 13, to move downwards as well. When the fixed rack 141 descends and meshes with the large gear 144, it drives the large gear 144 to rotate around the rotating rod 143. Simultaneously, the large gear 144 drives the small gear 145, which meshes with it, to rotate rapidly around the rotating rod 146. The rotation of the small gear 145 drives the coaxial cam 156 to rotate. The outer surface of the cam 156 pushes the roller 155, which is attached to it. The roller 155 overcomes the elastic force of the connecting spring 152 and the telescopic rod 153 through the L-shaped frame 154, causing the vertical frame 157 and the actuating plate 158 to move downwards. As cam 156 continues to rotate to the trough of the profile, connecting spring 152 pushes L-shaped frame 154 and actuating plate 158 upward to reset. With the continuous rotation of cam 156, actuating plate 158 performs intermittent reciprocating motion, tapping the water surface before the specimen enters the water, actively breaking the surface tension, and avoiding water ripples and air bubbles caused by continuous disturbance. After the specimen is completely submerged in the water tank 9, the suspended weight of the specimen in the water is weighed. Then, the specimen is removed from the water, and the surface water is gently wiped off with a damp towel until it is saturated and dry. Its saturated surface-dry weight is immediately weighed. Finally, based on the dry weight, the weight in water, and the saturated surface-dry weight, the measurement result of the concrete is obtained through the formula for calculating open porosity. Throughout the process, observation window 8 is used to monitor the working condition inside water tank 9 in real time. The counterweight 7 in hanging basket 6 maintains the overall balance of the device through balance frame 3, hook 4, and connecting line 5.

[0029] When in use, metal components that are in long-term contact with the water in the water tank 9, such as the second hanging basket 13, fixed rack 141, large gear 144, small gear 145, rotating rod 143, rotating rod 2 146, and cam 156, should be made of austenitic stainless steel to prevent rust from causing rotational jamming or water contamination that could affect weighing accuracy. The actuating plate 158 and roller 155 should be made of wear-resistant and smooth-surfaced polytetrafluoroethylene or nylon to avoid scratching the surface of the concrete specimen or generating debris during intermittent reciprocating tapping. The connecting spring 152 and telescopic rod 153 should be made of chrome-plated carbon steel or phosphor bronze to ensure that fatigue fracture or rust jamming does not occur during long-term reciprocating motion in a humid environment. The L-shaped frame 154 and the vertical frame 157 can be made of aluminum alloy or stainless steel, but care should be taken to use anti-loosening threaded adhesive or double nuts to lock the connection with the connecting spring 152 and the telescopic rod 153. Although the balance frame 3, hook 4, connecting line 5, hanging basket 6 and counterweight 7 do not directly contact the water, it is recommended to use brass or stainless steel to maintain the overall balance accuracy. The counterweight 7 should be filled with lead or cast iron to reduce its volume. The glass of the observation window 8 should be tempered glass or plexiglass to withstand the lateral pressure of the water in the tank 9.

[0030] Before use, check the meshing clearance between the fixed rack 141 and the large gear 144 to ensure there are no burrs or foreign objects stuck on the tooth surface, preventing tooth skipping or jamming during descent that could cause the specimen to fall suddenly and be damaged. Before placing the specimen into the second hanging basket 13, ensure that both the second hanging basket 13 and the actuating plate 158 are in their initial high positions to prevent the specimen from accidentally triggering the reciprocating actuating mechanism 15 before measurement begins, causing premature water agitation. The specimen should descend at a uniform and slow speed to ensure smooth meshing between the fixed rack 141 and the large gear 144, while allowing sufficient time for the reciprocating actuating mechanism 15 to complete intermittent tapping. Before each measurement, confirm through the observation window 8 that the water level in the water tank 9 completely submerges the specimen, and that the water temperature remains constant to avoid fluctuations in water density caused by temperature changes affecting weighing accuracy. After use, promptly wipe away any residual moisture from the surfaces of the fixed rack 141, large gear 144, small gear 145, rotating rod one 143, rotating rod two 146, and cam 156 with a soft cloth. Apply food-grade silicone oil or special waterproof grease to the tooth surfaces and rotating shafts to prevent rust and reduce friction. If the equipment is not used for an extended period, adjust the connecting spring 152 and telescopic rod 153 to a relaxed state to prevent the spring from undergoing prolonged compression and plastic deformation, which could affect the stability of the intermittent reciprocating motion.

[0031] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A concrete void measuring device, characterized by: The measuring platform (1) includes a suspended balance base (2) fixedly installed on the left side of the upper surface of the measuring platform (1). A balance frame (10) is installed on the upper surface of the suspended balance base (2). A hook (11) is fixedly installed on the lower surface of the balance frame (10). A connecting line (12) is installed on the hook (11). A hanging basket (13) is fixedly installed at one end of the connecting line (12). A water tank (9) is opened inside the measuring platform (1). A downward moving mechanism (14) is installed on the side of the hanging basket (13). A reciprocating moving mechanism (15) is installed at the power output end of the downward moving mechanism (14) to convert the meshing rotation power into reciprocating force. The downward moving mechanism (14) includes a fixed rack (141), a rectangular bar (142), a rotating rod one (143), a large gear (144), a small gear (145), and a rotating rod two (146). The left side of the fixed rack (141) is fixedly installed with the right side of the hanging basket two (13). The outer surface of the large gear (144) meshes with the right side of the fixed rack (141). The outer surface of the rotating rod one (143) is fixedly installed with the inside of the large gear (144). The inner wall of the rectangular bar (142) is rotatably installed with the outer surface of one end of the rotating rod one (143). The outer surface of the small gear (145) meshes with the outer surface of the large gear (144). The outer surface of the rotating rod two (146) is fixedly installed with the inside of the small gear (145). The reciprocating actuation mechanism (15) includes a fixed block (151), a connecting spring (152), a telescopic rod (153), an L-shaped frame (154), a vertical frame (157), and an actuating piece (158). The right side of the fixed block (151) is fixedly installed to the left side inside the water tank (9). One end of the connecting spring (152) is fixedly installed to the bottom of the fixed block (151). One end of the telescopic rod (153) is fixedly installed to the bottom of the fixed block (151). The upper surface of the L-shaped frame (154) is fixedly installed to the other end of the connecting spring (152) and the telescopic rod (153). The upper surface of the vertical frame (157) is fixedly installed to the lower surface of the L-shaped frame (154). The upper surface of the actuating piece (158) is fixedly installed to the lower surface of the vertical frame (157). The right side of the rectangular bar (142) is fixedly installed with the left side inside the water tank (9), and the outer surface of the rotating rod (146) is rotatably installed with the inner wall of the rectangular bar (142); a cam (156) is fixedly installed on the outer surface of the rectangular bar (142), and a roller (155) is attached to the outer surface of the cam (156); the bottom of the outer shell of the roller (155) is fixedly installed with the upper surface of the L-shaped frame (154).

2. A concrete void measuring device according to claim 1, wherein: A balance frame (3) is installed on the left side of the suspended balance base (2), and a hook (4) is fixedly installed at the bottom of the balance frame (3).

3. A concrete void measuring device according to claim 2, wherein: A connecting line (5) is installed on the surface of the hook (4), and a hanging basket (6) is installed at the bottom end of the connecting line (5). A counterweight (7) is fixedly installed inside the hanging basket (6).

4. A concrete void measuring device according to claim 1, wherein: The measuring platform (1) is equipped with an observation window (8) on its front side.

5. A concrete void measuring device according to claim 1, wherein: The second hanging basket (13) moves the fixed rack (141) down and meshes with the large gear (144) by placing the test piece inside, so that the test piece enters the water and breaks the surface tension of the water.

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