General-purpose water absorption test device

Abstract

To provide a general-purpose water absorption test device capable of measuring the amount of water absorption of a concrete surface without being affected by the orientation of the concrete surface.SOLUTION: A general-purpose water absorption test device includes a water absorption cup 1 and energizing means for energizing an open surface of the water absorption cup 1 to a concrete surface. The inside of the water absorption cup 1 is partitioned by an elastic membrane 12 into a water chamber 2 on the side in contact with the concrete surface and an air chamber 3 on the opposite side. In a test, the water chamber 2 is filled with water, and the air pressure adjusted by air supply to the air chamber 3 is transmitted to the water in the water chamber 2 through the elastic membrane 12 to adjust the water pressure of the water chamber 2 in contact with the concrete surface.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a general-purpose water absorption test device capable of measuring regardless of the orientation of the concrete surface to be measured.

Background Art

[0002] As one of the methods for evaluating the quality of the concrete surface layer, a water absorption test method for the concrete surface (SWAT: Surface Water Absorption Test) is known. As an example, Patent Document 1 discloses the following water absorption test device. Referring to FIG. 4, a conventional water absorption test device will be described. The conventional water absorption test device includes a short cylindrical water absorption cup a with one side open, a pair of suction cups of a negative pressure type for attaching the water absorption cup a to the concrete surface c, and a biasing means (not shown) composed of a combination with a fixing frame. The water absorption cup a forms a water absorption chamber on its open side, and a thin tubular cylinder b is erected at the top of the cup in communication with the water absorption chamber. After bringing the open surface of the water absorption chamber of the water absorption cup a into close contact with the surface of the concrete c to be measured, the inside of the water absorption chamber is filled with water, and a predetermined water pressure based on the water head difference of the cylinder b is applied to the concrete surface c. Immediately thereafter, by reading the change in the water level in the cylinder b at all times, it is a method of calculating and evaluating the water absorption rate of the concrete surface c. The reading of the change in the water level in the cylinder b can be done visually, but it can also be detected by a water pressure sensor attached to the cup a to calculate the change amount.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional water absorption test apparatus shown in Patent Document 1, the following problems exist. <1> As shown in FIG. 4, when the concrete surface c to be measured is a floor surface or a wall surface, measurement is possible, but when the object to be measured is an upward-facing structure such as a tunnel ceiling surface or the back surface of a bridge floor slab, measurement is impossible. This is because in such structures, the cylinder b cannot be arranged vertically, and a predetermined water head difference cannot be ensured. <2> Further, in the case of floor surface measurement, the cylinder b must be attached to the end face of the water absorption cup a, and in the case of wall surface measurement, the cylinder b must be attached to the side face of the water absorption cup a. Therefore, it is necessary to reattach the cylinder b every time measurement is performed.

[0005] An object of the present invention is to provide a water absorption test apparatus that can solve the above problems.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention is a water absorption test apparatus comprising a water absorption cup having a bottomed structure with an open side in contact with the concrete surface, and biasing means for biasing the open surface of the water absorption cup against the concrete surface. The water absorption cup is partitioned inside by an elastic membrane arranged parallel to the concrete surface to be measured, and is divided into a water chamber on the side in contact with the concrete surface and an air chamber on the opposite side. A water-permeable plate body is provided on the open surface of the water chamber of the water absorption cup. During the test, the water chamber is filled with water, and the air pressure adjusted by supplying air to the air chamber is transmitted to the water in the water chamber through the elastic membrane to enable adjustment of the water pressure in the water chamber. Furthermore, in another aspect of the present invention, an air pressure sensor is arranged in the air chamber so that the air pressure in the air chamber can be detected by the air pressure sensor. Furthermore, in another aspect of the present invention, a water pressure sensor is arranged in the water chamber so that the water pressure in the water chamber can be detected by the water pressure sensor. In another aspect of the present invention, as a water-permeable plate covering the open surface of the water absorption cup, a perforated plate disposed on the water chamber side and a water-permeable mesh disposed on the open surface side are laminated.

Advantages of the Invention

[0007] The general-purpose water absorption test device of the present invention can obtain the following effects. <1> It is possible to measure the water absorption amount of a concrete surface such as a ceiling surface or the lower surface of a bridge, and the measurement can be performed without being affected by the orientation of the concrete surface. <2> Since there is no need to stand the cylinder as in the prior art, there is no need to attach and remove the cylinder for each measurement of the water absorption amount of the horizontal and vertical surfaces of the concrete, and rapid measurement is possible. <3> The pressure management of the water in the water chamber of the water absorption cup can be performed easily and accurately.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] Hereinafter, a preferred embodiment of the general-purpose water absorption test device of the present invention will be described in detail with reference to the drawings.

Example

[0010] <1> Overall configuration of the general-purpose water absorption test device. The general-purpose water absorption test device of the present invention includes a water absorption cup 1, a biasing means for pressing the water absorption cup 1 against the target surface, a means for supplying water to the water absorption cup 1, and a means for supplying compressed air to the water absorption cup 1.

[0011] The biasing means of the water absorption cup 1 can adopt a known mounting mechanism such as a support frame attached to the water absorption cup 1, a pair of suction cups for attaching the support frame to the concrete surface, or the diversion of a separator remaining on the concrete placement surface.

[0012] <2>Water absorption cup. The water absorption cup 1 is a cylindrical body with a bottomed structure having an open top like a pot (hereinafter, for the sake of easy understanding of the explanation, it is assumed to be fixed to the ceiling surface, and is expressed as the top surface, bottom surface, side surface, etc., but does not limit the posture during use). An annular sealing material 11 is provided at the edge of the upper end of the water absorption cup 1, that is, the edge on the open side. This annular sealing material 11 is made of a material that can be elastically compressed and deformed. Therefore, when the water absorption cup 1 is pressed against a concrete surface with a non-smooth surface, this sealing material 11 can be deformed to adhere to the concrete surface.

[0013] <3>Partition between the water chamber and the air chamber. The internal space of the water absorption cup 1 has an elastic membrane 12 having a function as a horizontal partition plate in the middle, forming a water chamber 2 on the open side of the elastic membrane 12 in contact with the concrete, and forming an air chamber 3 on the opposite back side of the elastic membrane 12.

[0014] The elastic membrane 12 is made of a sheet material such as rubber that has both water barrier properties and flexibility and can be freely deformed.

[0015] In order to maintain the posture of the elastic membrane 12 as a partition plate, a perforated support plate 13 with holes is arranged on the lower surface of the elastic membrane 12. This perforated support plate 13 can be composed of, for example, an acrylic plate. The diameter and number of holes formed in the perforated support plate 13 can be appropriately selected. Note that the perforated support plate 13 is not an essential member and can also be omitted.

[0016] <4>Water chamber. The water chamber 2 disposed above the water-absorbing cup 1 closes its upper open surface with a laminate of a perforated plate 21 and a mesh 22. This perforated plate 21 and mesh 22 that are laminated and disposed are capable of passing water. As the mesh 22, a known woven mesh formed by intersecting wire rods can be used.

[0017] The reason for using the perforated plate 21 and the mesh 22 by overlapping them is that both cooperate to cut the surface tension of water and quickly drain the water without leaving air bubbles between the perforated support plate 13 and the concrete surface. The mesh 22 is a spacing holding member that forms a gap between the perforated support plate 13 and the concrete surface, and by quickly passing water through this gap, it is possible to effectively avoid air bubbles staying in the water chamber 2.

[0018] A water pressure sensor 23 is installed in the water chamber 2 so that the water pressure inside the water chamber 2 can be detected from the outside.

[0019] The pressurized water in the water chamber 2 penetrates through the mesh 22 on the upper surface of the perforated plate 21 installed in a lid shape and reaches the surface of the concrete. At that time, due to the following reasons, it is necessary to prevent air from accumulating in the pressurized water.

[0020] <5> Reasons for not generating air bubbles in the water chamber. Without the perforated plate 21 and the mesh 22 that serve as the lid of the water chamber 2, air bubbles are likely to remain between the water chamber 2 and the concrete surface when recovering the residual water in the water chamber 2. If air bubbles remain in the water chamber 2, air bubbles accumulate on the surface of the concrete to be measured, water does not spread evenly, and water absorption of the concrete is inhibited at the locations where air bubbles accumulate. As a result, an accurate surface water absorption test cannot be performed. Therefore, in the present invention, by adopting the combination of the perforated plate 21 and the mesh 22, it is configured to be able to remove air bubbles simultaneously with water recovery.

[0021] <6> Water supply and drainage channels and water supply means. For water supply and drainage to the water chamber 2, a water supply path P1 and a drainage path P2 are provided in the water chamber 2. The water chamber 2 and an external water supply tank T1 are communicated with each other by a water supply path P1 with a valve, and the space between the water chamber 2 and an external water recovery tank T2 is communicated with each other by a drainage path P2 with a valve, so as to enable water supply and drainage from the water supply path P1 to the drainage path P2.

[0022] In this example, a water supply means for supplying water to the water chamber 2 by supplying compressed air from a pressure pump U to the water supply tank T1 is shown. However, in addition to this, a simple manual injection means such as a syringe can also be adopted, which is effective for use outdoors without power supply.

[0023] Note that the water supply and drainage into the water chamber 2 may be configured to be performed from the drainage path P2 to the water supply path P1.

[0024] <7>Air chamber. As described above, an air chamber 3 is formed in the lower half of the water suction cup 1. An air pressure sensor 31 is arranged in the air chamber 3.

[0025] <8>Air supply path and compressed air supply means. Furthermore, an air supply path P3 is connected to the air chamber 3. In FIG. 1, a form of supplying the compressed air of the pressure pump U to the air chamber 3 through the air supply path P3 is shown. In short, any configuration that can supply the pressure-adjusted compressed air into the air chamber 3 through an external pressure pump U or a manual pump (not shown) etc. may be used.

[0026] [Test method] Next, a water absorption test method for a concrete surface using a general-purpose water absorption test device will be described. In this example, the ceiling surface, which could not be measured by a conventional water absorption test device, will be described as an example. However, in the present invention, the water absorption test is not limited to the ceiling surface, and the water absorption test on the floor surface, wall surface, and inclined surface is also possible.

[0027] <1>Installation of the water suction cup. To attach the above-described water-absorbing cup 1 to the ceiling surface, for example, a support frame 4 which is a long rod-shaped body shown in FIG. 3 is used. This support frame 4 is attached to the ceiling surface with two points at both ends thereof as fixing points 41, and the water-absorbing cup 1 is set upward in close contact with the concrete surface between the two fixing points 41. If the fixing points 41 are slidable in the axial direction with respect to the support frame 4, the positions of the fixing points can be freely selected.

[0028] To fix the fixing points 41 to the concrete surface, for example, a method of removing the packing mortar after the cone of the separator at the time of concrete placement to expose the screw at the end of the separator and using it, a method of applying negative pressure to a cup-shaped suction plate as described in Patent Document 1 and fixing it, etc., known methods can be adopted.

[0029] By strongly pressing the water-absorbing cup 1 against the concrete surface, the annular sealing material 11 at the upper edge of the water-absorbing cup 1 can be deformed to form a close contact state.

[0030] Note that as described above, the direction of the surface to which the water-absorbing cup 1 is attached is not limited to upward, lateral, downward, inclined surfaces, etc., and the arrangement as shown in the figure is only an example.

[0031] <2>Water supply into the water chamber. While draining the residual water in the water chamber 2, at the same time, the water supply path P1 from the water supply tank T1 is opened, and the pressurized water is filled into the water chamber 2 to make it full. Then, the water in the water chamber 2 comes into contact with the concrete surface under pressure.

[0032] <3>Air supply into the air chamber. Next, pressurized air is supplied into the air chamber 3 through the air supply path P3. Then, the pressure in the air chamber 3 rises and the elastic membrane 12 is displaced toward the water chamber 2. Along with the displacement of the elastic membrane 12, the water pressure in the water chamber 2 rises and penetrates into the concrete surface.

[0033] The change in water pressure within this water chamber 2 is detected by a water pressure sensor 23, and the air pressure is adjusted so that the water pressure reaches the accurate initial water pressure (3 kPa). In this way, through pressure management by supplying compressed air to the air chamber 3, accurate water pressure management within the water chamber 2 can be achieved.

[0034] Particularly, since water is an incompressible fluid, it is technically difficult to directly adjust and manage the water pressure at a low water pressure (3 kPa). However, since air is a compressible fluid, there is an effect that fine adjustment and management of pressure are easy.

[0035] <4>Measurement of the water absorption amount of the concrete surface. Set the initial setting with the initially applied water pressure (3 kPa) as the zero point. In this state, measure the pressure change within the air chamber 3 at a predetermined inspection time using either one of the sensors, namely the air sensor 31 or the water pressure sensor 23 within the water chamber 2, or both sensors.

[0036] It is also possible to omit the water pressure sensor 23 and measure using only the air sensor 31. In this case, the change in water pressure within the water chamber 2 is regarded as the change in air pressure within the air chamber 3, and the change in water pressure within the water chamber 2 is measured indirectly through the air chamber 3. Also, the measurement data of the air sensor 31 may be collated with the measurement data by the water pressure sensor 23 and used complementarily.

[0037] The measured data can also be transmitted via Bluetooth (registered trademark) to a smartphone or the like for display.

[0038] Note that the present invention is an invention of a general-purpose water supply test apparatus for measuring the water absorption amount of the concrete surface, and since the measurement method is widely known, further detailed description is omitted.

[0039] [Effects of the Embodiment] <1>Since a cylinder is not used as in the conventional water absorption test apparatus, it is possible to measure the concrete surface not only in the downward and lateral directions but also in the upward direction. Therefore, it is possible to perform a water absorption test on upward-facing surfaces such as tunnel ceiling surfaces and the back surfaces of bridge decks that were previously impossible. <2>Since a cylinder is not used as in conventional test devices, it is not necessary to change the attachment of the cylinder depending on whether the measurement surface of the concrete is horizontal or vertical, enabling rapid measurement. <3>Although it is technically difficult to directly adjust the water pressure, in the present invention, since the change in water pressure is regarded as a change in air pressure, the pressure management of the water chamber can be accurately performed. Therefore, the water absorption amount on the concrete surface can be accurately determined. <4>By adopting a combination of a perforated plate and a mesh, the surface tension of water can be effectively cut at the start of measurement, and air bubbles can be quickly discharged to the outside.

Description of Symbols

[0040] 1: Water absorption cup 2: Water chamber 3: Air chamber 23: Water pressure sensor 31: Air pressure sensor

Claims

1. A general-purpose water absorption test device comprising a bottomed water absorption cup with an open side in contact with the concrete surface, and biasing means for biasing the open surface of the water absorption cup against the concrete surface, wherein the water absorption cup is partitioned internally by an elastic membrane into a water chamber on the side in contact with the concrete surface and an air chamber on the opposite side, a water-permeable plate body is provided on the open surface of the water chamber of the water absorption cup, during the test, the water chamber is filled with water, and the air pressure adjusted by supplying air to the air chamber is transmitted through the elastic membrane to the water in the water chamber so that the water pressure in the water chamber can be adjusted. General-purpose water absorption test device.

2. The general-purpose water absorption test device according to claim 1, wherein an air pressure sensor is arranged in the air chamber so that the air pressure in the air chamber can be detected by the air pressure sensor.

3. The general-purpose water absorption test device according to claim 1, wherein a water pressure sensor is arranged in the water chamber so that the water pressure in the water chamber can be detected by the water pressure sensor.

4. The general-purpose water absorption test device according to claim 1, wherein the water-permeable plate body covering the open surface of the water absorption cup is formed by laminating a perforated plate arranged on the water chamber side and a water-permeable mesh arranged on the open surface side.

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