Device for Measuring Spacing between Main Reinforcement Bars of Concrete Beam and Bottom Formwork and Its Using Method

Abstract

The present invention relates to a device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork and its usage method. To fill the gap in the prior art, the device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork includes a double-tube plug board, a plug rod, and a hook rod. The double-tube plug board includes two connected long tubes. The plug rod and the hook rod are respectively inserted into the two long tubes. A length scale line is provided on the upper part of the plug rod. The lower end of the hook rod is bent to one side to form a semi-circular hook part. A protruding plate is further provided on the outer side of the lower end of the long tube where the hook rod is located. The protruding plate is provided with a through groove and a notch. The notch intersects with the through groove, and the notch and the hook part are opposite to each other. A plurality of clamping plates are respectively provided at the tops of the two long tubes. External threads are also provided on the long tubes and are respectively equipped with locking nuts. By tightening or loosening the locking nuts, the clamping plates can be locked or released with the plug rod or the hook rod. The device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork and its usage method according to the present invention are simple and convenient, and are suitable for measuring the thickness of the main reinforcement bar protection layer during the pouring of concrete beams.

Description

Technical Field

[0001] The present invention relates to a device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork and a method for using the same. Background Art

[0002] When pouring a concrete beam, in order to enable the main reinforcement bars to exert the maximum tensile performance, the main reinforcement bars of the concrete beam need to be arranged at the lower part of the concrete beam. However, due to the requirements of rust prevention and corrosion prevention, they cannot be too close to the pouring lower surface, and they cannot be exposed. The concrete between the main reinforcement bars and the lower surface of the concrete beam is called the steel bar protection layer, which generally shall not be less than 40 mm.

[0003] The Chinese utility model patent with the publication number of CN 208635734 U, which was publicly disclosed on March 22, 2019, discloses a device for detecting the distance between a steel bar mesh and a formwork, including: a pair of longitudinal tracks connected to the bottom surface of a cylindrical steel bar mesh; a trolley is rollingly connected to the tracks, and the trolley is electrically connected to a controller; a three-dimensional laser scanner is connected to the front end of the top of the trolley, and the three-dimensional laser scanner is electrically connected to a computer. During detection, the controller controls the trolley to slowly move forward, the three-dimensional laser scanner at the front end of the top of the trolley rotates and scans in all directions, and the scanned information is input into the computer for analysis to determine whether the distance between each surface of the steel bar mesh and the corresponding surface of the formwork meets the design requirements. After the detection work is completed, the tracks and the trolley are removed, and then pouring is carried out.

[0004] This utility model has a simple structure, but it can only be used before pouring the concrete mortar. In the prior art, after the formwork of the concrete beam is erected, the steel bars of the concrete beam are erected by stools, and then the concrete mortar is poured. However, pouring the concrete mortar will cause a large impact on the steel bar cage and easily knock down the stools, resulting in too small a distance between the main reinforcement bars and the lower surface of the concrete beam after the concrete solidifies, not meeting the standards.

[0005] To detect the thickness of the steel bar protection layer, the prior art requires drilling holes in the concrete beam, finding the holes drilled into the main reinforcement bars, and then measuring the depths of the corresponding holes to obtain the thickness of the steel bar protection layer to be measured. It is often necessary to try drilling at different positions multiple times to accurately drill into the main reinforcement bars, and multiple drillings will inevitably damage the concrete beam. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to fill the above gaps in the prior art and provide a measuring device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork and a method for using the same after pouring the concrete mortar and before initial setting.

[0007] To solve the above technical problems, the device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork includes a double-tube insertion plate, an insertion rod, and a hook rod. The double-tube insertion plate includes two connected long tubes that are parallel to each other. The insertion rod and the hook rod are respectively inserted into the two long tubes. The upper part of the insertion rod is provided with length scale lines. The lower end of the hook rod is bent to one side to form a semi-circular hook part. A protruding plate is also provided on the outer side of the lower end of the long tube where the hook rod is located. A through groove for the hook part to enter and exit is provided on the protruding plate. Notches are also opened at the lower edges of the two side walls of the protruding plate. The notches and the hook part are opposite to each other, and the main reinforcement bars of the concrete beam to be measured can be clamped in the middle. Three or four longitudinal slits are respectively provided at the tops of the two long tubes. The above longitudinal slits divide the tops of the two long tubes into multiple clamping plates with an arc-shaped cross-section. External threads are also provided on the long tubes below the clamping plates, and locking nuts are respectively equipped. Each locking nut is composed of a conical tube part and a straight tube part connected up and down. The inner wall of the straight tube part is provided with internal threads that match the external threads. The inner diameter of the large end of the conical tube part ≥ the outer diameter of the long tube, and the inner diameter of the hook rod or the insertion rod inside the corresponding long tube ≤ the inner diameter of the small end of the conical tube part < the outer diameter of the upper end of the long tube. By tightening the locking nut, the clamping plate of the corresponding long tube can be squeezed and fixed together with the insertion rod or the hook rod inside the long tube. By loosening the locking nut, the corresponding clamping plate releases the insertion rod or the hook rod, and the insertion rod or the hook rod can slide up and down inside the corresponding long tube. When the insertion rod is flush with the lower end of the long tube where it is located, the zero starting point of the length scale line on the insertion rod is exactly flush with the top of the locking nut on it. With such a design, by reading the length scale line of the insertion rod exposed at the top of the locking nut, the distance between the main reinforcement bars of the concrete beam to be measured and the corresponding bottom formwork can be obtained. If it does not meet the standard, emergency treatment can also be carried out. When the distance meets the standard, the distance between the two after the concrete solidifies is the thickness of the steel bar protection layer.

[0008] As an optimization, multiple uniformly distributed longitudinal anti-slip ridges are provided on the outer circumference of the straight tube part of the locking nut. The tops of the insertion rod and the hook rod are respectively bent into rings. The longitudinal bisecting plane of the protruding plate is perpendicular to the plane passing through the axis lines of the two long tubes. With such a design, the structure is simple and convenient to use.

[0009] The usage method of the aforesaid device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork includes the following steps:

[0010] ①. After the concrete mortar of the concrete beam to be measured is poured and before the concrete mortar begins to set, take the aforesaid device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork, make the insertion rod flush with the lower end of the long tube where it is located, and tighten the locking nut on the insertion rod to make the hook head of the hook rod away from the protruding plate, and tighten the locking nut on the hook rod.

[0011] ②. Then hold the double-tube plug board by hand, insert the hook head below the double-tube plug board into the non-setting concrete mortar from the middle until it feels that the hook head touches the bottom formwork. Then turn the outer end of the hook head outward and move it outward until it feels that the hook rod touches the main reinforcement of the concrete beam to be measured. Then lift the double-tube plug board until the hook head hooks the main reinforcement of the concrete beam to be measured. Then loosen the locking nut on the hook rod, turn the hook rod to the vertical state, hold the hook rod with one hand, and press down the double-tube plug board together with the insertion rod with the other hand until the notches of the hook head and the protruding plate respectively clamp the main reinforcement of the concrete beam to be measured from the upper and lower sides. Then tighten the locking nut on the hook rod to lock the hook rod and the double-tube plug board together.

[0012] ③. Then, loosen the locking nut on the insertion rod and press down the insertion rod so that its lower end abuts against the matching bottom formwork. At this time, the length indicated by the length scale line exposed at the top of the locking nut on the insertion rod is the distance between the main reinforcement of the concrete beam to be measured and the matching bottom formwork.

[0013] ④. Finally, loosen the locking nut on the insertion rod to separate the hook head from the protruding plate, and remove the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork from the main reinforcement of the concrete beam to be measured. Wash it with clean water and set it aside for later use. With such a design, using the aforementioned method and device, the distance between the main reinforcement of the concrete beam to be measured and the corresponding bottom formwork can be conveniently measured after the concrete is poured and before it sets, which is very convenient.

[0014] The device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork of the present invention and its using method are simple and convenient, and are suitable for measuring the thickness of the main reinforcement protection layer during the pouring of the concrete beam. Brief Description of the Drawings

[0015] The following further describes the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork of the present invention and its using method in conjunction with the drawings:

[0016] Figure 1 is a three-dimensional structural schematic diagram of the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork;

[0017] Figure 2 is a three-dimensional structural schematic diagram of the insertion rod of the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork;

[0018] Figure 3 is a three-dimensional structural schematic diagram of the hook rod of the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork;

[0019] Figure 4 is a three-dimensional structural schematic diagram of the locking nut of the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork;

[0020] Figure 5 is a three-dimensional structural schematic diagram of the double-tube plug board of the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork;

[0021] Figure 6It is a schematic diagram of using the hook of the device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork to hook the main reinforcement bars of the concrete beam to be measured;

[0022] Figure 7 It is a schematic diagram of using the hook and the protruding plate of the device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork to clamp the main reinforcement bars of the concrete beam to be measured;

[0023] Figure 8 It is a schematic diagram of the third step of the device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork.

[0024] In the figure: 1 is a double-tube insert plate, 11 is a long tube, 12 is a protruding plate, 13 is a through groove, 14 is a notch, 15 is a longitudinal slit, 16 is a clamping plate, 17 is an external thread, 18 is a longitudinal anti-slip rib, 2 is an insertion rod, 21 is a length scale line, 3 is a hook rod, 31 is a hook part, 4 is the main reinforcement bar of the concrete beam to be measured, 5 is a locking nut, 51 is a tapered tube part, 52 is a straight tube part, 19 is a matching bottom formwork. Embodiment

[0025] Embodiment 1: As Figures 1 - 5 shown, the device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork includes a double-tube insert plate 1, an insertion rod 2 and a hook rod 3. The double-tube insert plate 1 includes two connected long tubes 11 which are parallel to each other. The insertion rod 2 and the hook rod 3 are respectively inserted into the two long tubes 11. The upper part of the insertion rod 2 is provided with a length scale line 21. The lower end of the hook rod 3 is bent to form a semi-circular hook part 31 on one side. There is also a protruding plate 12 on the outer side of the lower end of the long tube 11 where the hook rod 3 is located. The protruding plate 12 is provided with a through groove 13 for the hook part 31 to enter and exit. The lower edges of the two side walls of the protruding plate 12 are also provided with notches 14. The notches 14 are semi-circular notches, and the axis line thereof is perpendicular to the longitudinal bisecting plane of the through groove 13. The notches 14 and the hook part 31 are opposite to each other and can clamp the main reinforcement bar 4 of the concrete beam to be measured in the middle. Three or four longitudinal slits 15 are respectively provided at the tops of the two long tubes 11. The longitudinal slits 15 divide the tops of the two long tubes 11 into a plurality of clamping plates 16 with an arc-shaped cross section. The long tubes below the clamping plates 16 are also provided with external threads 17 and are respectively equipped with locking nuts 5. Each locking nut 5 is composed of an upper and lower connected tapered tube part 51 and a straight tube part 52. The inner wall of the straight tube part 52 is provided with an internal thread (not shown in the figure) matching the external thread 17. The inner diameter of the large end of the tapered tube part 51 ≥ the outer diameter of the long tube 11. The inner diameter of the insertion rod 2 or the hook rod 3 inside the corresponding long tube 11 ≤ the inner diameter of the small end of the tapered tube part 51 < the outer diameter of the upper end of the long tube 11. By tightening the locking nut 5, the clamping plate 16 of the corresponding long tube 11 can be squeezed and fixed together with the insertion rod 2 or the hook rod 3 inside the long tube 11. By loosening the locking nut 5, the corresponding clamping plate 16 releases the insertion rod 2 or the hook rod 3, and the insertion rod 2 or the hook rod 3 can slide up and down inside the corresponding long tube 11. When the insertion rod 2 is flush with the lower end of the long tube 11 where it is located, the zero starting point of the length scale line on the insertion rod 2 is exactly flush with the top of the locking nut 5 thereon.

[0026] A plurality of longitudinally distributed anti-slip ridges 18 are provided on the outer circumference of the straight pipe portion 52 of the locking nut 5. The top ends of the insertion rod 2 and the hook rod 3 are respectively bent into a ring shape. The longitudinal bisecting plane of the protruding plate 12 is perpendicular to the plane passing through the axis lines of the two long pipes 11.

[0027] The using method of the device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork includes the following steps:

[0028] ①. After the concrete mortar of the concrete beam to be measured is poured and before the concrete mortar begins to set, take the device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork. Make the insertion rod 2 flush with the lower end of the long pipe 11 where it is located, and tighten the locking nut 5 on the insertion rod, so that the hook head 31 of the hook rod 3 is far away from the protruding plate 12, and tighten the locking nut 5 on the hook rod 3.

[0029] ②. Then hold the double-pipe insertion plate 1 by hand, and insert the hook head 31 below the double-pipe insertion plate 1 into the non-set concrete mortar (not shown in the figure) from the middle until it is felt that the hook head 31 touches the matching bottom formwork 19 (taking the feeling that the hook head 31 touches a large-area flat obstacle as the standard). Then turn the outer end of the hook head 31 outwards and move it outwards until it is felt that the hook rod 3 touches the main reinforcement bar 4 of the concrete beam to be measured. Then lift the double-pipe insertion plate 1 until the hook head 31 hooks the main reinforcement bar 4 of the concrete beam to be measured, as Figure 6 shown.

[0030] Then loosen the locking nut 5 on the hook rod 3, turn the hook rod 3 to a vertical state, hold the hook rod 3 with one hand, and press down the double-pipe insertion plate 1 together with the insertion rod 2 with the other hand (during the pressing process, it should be noted that the hook head 31 keeps relative to the through groove 13 on the protruding plate 12) until the hook head 31 and the notch 14 of the protruding plate 12 respectively clamp the main reinforcement bar 4 of the concrete beam to be measured from the upper and lower sides. Then tighten the locking nut 5 on the hook rod 3 to lock the hook rod 2 and the double-pipe insertion plate 1 together, as Figure 7 shown.

[0031] ③. Then, loosen the locking nut 5 on the insertion rod 2, press down the insertion rod 2 so that its lower end abuts against the matching bottom formwork 19. At this time, the length indicated by the length scale line 21 exposed at the top of the locking nut 5 on the insertion rod 2 is the distance between the main reinforcement bar 4 of the concrete beam to be measured and the matching bottom formwork 19, as Figure 8 shown.

[0032] ④. Finally, loosen the locking nut 5 on the insertion rod 2 to separate the hook head 31 from the protruding plate 12, and remove the device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork from the main reinforcement bar 4 of the concrete beam to be measured, and wash it with clean water for future use.

Claims

1. A device for measuring the distance between the main reinforcement bars of a concrete beam and the bottom formwork, characterized in that: It includes a double-tube insertion plate, an insertion rod and a hook rod. The double-tube insertion plate includes two connected long tubes which are parallel to each other. The insertion rod and the hook rod are respectively inserted into the two long tubes. A length scale line is provided on the upper part of the insertion rod. The lower end of the hook rod bends to one side to form a semi-circular hook part. A protruding plate is also provided on the outer side of the lower end of the long tube where the hook rod is located. A through groove for the hook part to enter and exit is provided on the protruding plate. Semi-circular notches are also opened at the lower edges of the two side walls of the protruding plate. The axis line of the semi-circular notch is perpendicular to the longitudinal bisecting plane of the through groove. The notch and the hook part are opposite to each other, and the main reinforcement of the concrete beam to be measured is clamped in the middle. Three or four longitudinal slits are respectively provided at the tops of the two long tubes. The longitudinal slits divide the tops of the two long tubes into multiple clamping plates with an arc-shaped cross-section. External threads are also provided on the long tubes below the clamping plates, and locking nuts are respectively equipped. Each locking nut is composed of a conical tube part and a straight tube part connected up and down. Internal threads matching the external threads are provided on the inner wall of the straight tube part. The inner diameter of the large end of the conical tube part ≥ the outer diameter of the long tube, and the outer diameter of the hook rod or the insertion rod inside the corresponding long tube ≤ the inner diameter of the small end of the conical tube part < the outer diameter of the upper end of the long tube. Tighten the locking nut to squeeze and fix the clamping plate of the corresponding long tube and the insertion rod or the hook rod inside the long tube together. Loosen the locking nut, and the corresponding clamping plate releases the insertion rod or the hook rod. The insertion rod or the hook rod slides up and down in the corresponding long tube. When the insertion rod is flush with the lower end of the long tube where it is located, the zero starting point of the length scale line on the insertion rod is exactly flush with the top of the locking nut on it.

2. The device for measuring the distance between the main reinforcement bars of the concrete beam and the bottom formwork according to claim 1, wherein: Longitudinal anti-slip ridges evenly distributed are provided on the outer circumference of the straight tube part of the locking nut. The tops of the insertion rod and the hook rod respectively bend into rings. The longitudinal bisecting plane of the protruding plate is perpendicular to the plane passing through the axis lines of the two long tubes.

3. A method for using the device for measuring the distance between the main reinforcement of a concrete beam and the bottom formwork according to claim 1 or 2, comprising the following steps: ①. After the concrete mortar of the concrete beam to be measured is poured and before the concrete mortar begins to set, take the device for measuring the distance between the main reinforcement of the concrete beam and the bottom formwork according to claim 1 or 2, make the insertion rod flush with the lower end of the long tube where it is located, and tighten the locking nut on the insertion rod, make the hook head of the hook rod away from the protruding plate, and tighten the locking nut on the hook rod. ②. Then hold the double-tube insertion plate by hand, insert the hook head below the double-tube insertion plate into the non-set concrete mortar from the middle until it feels that the hook head touches the bottom formwork, then turn the outer end of the hook head outwards and move it outwards until it feels that the hook rod touches the main reinforcement of the concrete beam to be measured, then lift the double-tube insertion plate until the hook head hooks the main reinforcement of the concrete beam to be measured, then loosen the locking nut on the hook rod, turn the hook rod to the vertical state, hold the hook rod with one hand, and press down the double-tube insertion plate together with the insertion rod with the other hand until the hook head and the notch of the protruding plate respectively clamp the main reinforcement of the concrete beam to be measured from the upper and lower sides, then tighten the locking nut on the hook rod to lock the hook rod and the double-tube insertion plate together. ③. Then, loosen the locking nut on the insertion rod, press down the insertion rod so that its lower end abuts against the matching bottom formwork. At this time, the length represented by the length scale line exposed at the top of the locking nut on the insertion rod is the distance between the main reinforcement of the concrete beam to be measured and the matching bottom formwork. ④. Finally, loosen the lock nut on the hook rod to separate the hook head from the protruding plate, remove the device for measuring the distance between the main bars of the concrete beam and the bottom formwork from the main bars of the concrete beam to be measured, and wash it with clean water for later use.

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