Air permeation measuring device, air permeation measuring method, and air permeation measuring system

Abstract

An air permeation measuring device (10) comprises: an attachment (11) having an opening (11b); a cylinder (13) having an internal space (13a) that communicates with the opening (11b); a piston (14) that changes the volume of the internal space (13a); a pressure sensor (16) that detects the pressure in the internal space (13a); and a first control unit (17). The first control unit (17) calculates the air permeation speed and identifies the air inflow amount corresponding to the air permeation speed.

Description

Air permeability measuring device, air permeability measuring method, and air permeability measuring system

[0001] The present disclosure relates to an air permeability measurement device, an air permeability measurement method, and an air permeability measurement system.

[0002] Patent Document 1 describes an air permeability measurement method that uses a simple air permeability tester or the like, which can measure the mass transfer resistance of the surface layer of a porous material.

[0003] Non-Patent Document 1 describes a single chamber method in which the air permeability index is calculated by reducing the pressure inside a chamber attached to the surface of concrete and then measuring the time required for the air pressure inside the chamber to return to normal.

[0004] Non-Patent Document 2 describes a method in which the desiccator lid is placed in close contact with the concrete surface, the inside of the lid is depressurized, and then the time it takes for the vacuum level to decrease due to air flowing in from the concrete surface is measured to calculate the air suction rate.

[0005] Japanese Patent Application Publication No. 2017-72489

[0006] Junji Yamazaki, Keiichi Imamoto, Akio Tanaka, Takeshi Kato, "Study on Repeated Measurements and Calibration of Testing Machines in Air Permeability Tests," Proceedings of the Japan Concrete Institute, Vol. 39, No. 1, 2017, pp. 1921-1926. Masae Kunimoto, Noboru Yuasa, Yoshio Kasai, Isamu Matsui, "Proposal of an Evaluation Method for Cold Joints in Structural Concrete," Proceedings of the Annual Meeting of the Architectural Institute of Japan, 2000, pp. 433-434.

[0007] An object of one aspect of the present disclosure is to provide an air permeability measurement device, an air permeability measurement method, and an air permeability measurement system that can evaluate the air permeability of concrete or the like in a short period of time.

[0008] In order to solve the above problems, an air permeability measuring device according to one embodiment of the present disclosure includes an attachment that is placed on the surface of an object to be measured and has an opening facing the object to be measured, a cylinder that has an internal space that communicates with the opening of the attachment and is fixed to the attachment, a piston that changes the volume of the internal space by sliding on the inner circumferential surface of the cylinder, a pressure sensor that detects the pressure of the internal space via the opening of the attachment, and a control unit. The control unit calculates a pressure difference between a first pressure, which is the pressure in the internal space at a certain time after applying a tensile force to the piston to reduce the pressure, and a second pressure, which is the pressure in the internal space after a predetermined measurement time has elapsed since the first pressure was detected, with the attachment in close contact with the surface of the object to be measured, and calculates an air permeability rate, which is an index for evaluating the air permeability of the object to be measured, by dividing the pressure difference by the measurement time.The control unit identifies the air inflow rate corresponding to the air permeability rate by referring to the correlation between the calculated air permeability rate and an air inflow rate, which is the amount of air that flows into the internal space as the internal space is reduced in pressure.

[0009] According to one aspect of the present disclosure, the air permeability of concrete or the like can be evaluated in a short period of time.

[0010] 1 is a block diagram showing the configuration of an air permeability measurement system according to a first embodiment of the present disclosure. FIG. 2 is a diagram showing the overall configuration of an air permeability measurement device according to the first embodiment. FIG. 3 is a flowchart showing the flow of evaluating the air permeability of concrete using the air permeability measurement device according to the first embodiment. FIG. 4 is a diagram showing how the air permeability of concrete is measured using the air permeability measurement device according to the first embodiment. FIG. 5 is a graph showing pressure changes in the internal space of a cylinder when measuring the air permeability of concrete using the air permeability measurement device according to the first embodiment. FIG. 6 is a correlation diagram showing the correlation between air permeation rate and air inflow amount. FIG. 7 is a flowchart showing the flow of a process for detecting air leaks using the air permeability measurement device according to the first embodiment. FIG. 8 is a graph showing pressure changes during measurement using the air permeability measurement device when gaskets made of different materials are used according to the first embodiment. FIG. 9 is a block diagram showing the configuration of an air permeability measurement device according to a second embodiment of the present disclosure.

[0011] [Embodiment 1] Hereinafter, an air permeability measurement device 10 and an air permeability measurement system 100 according to Embodiment 1 of the present disclosure will be described with reference to Figures 1 to 8. Figure 1 is a block diagram showing the configuration of the air permeability measurement system 100. Figure 2 is a diagram showing the overall configuration of the air permeability measurement device 10.

[0012] As shown in Fig. 1, the air permeability measurement system 100 includes an air permeability measurement device 10 and a communication device 20 capable of communicating with the air permeability measurement device 10. The air permeability measurement device 10 is used to measure the air permeability of the surface layer of an object to be measured.

[0013] An example of the object to be measured is concrete, but the object to be measured is not limited to concrete and may be mortar, cement paste, or the like.

[0014] Here, air permeability is a property that indicates the ease with which air passes through a measurement object. Air permeability is affected by the moisture content of the measurement object, and the higher the moisture content, the lower the air permeability. By measuring the air permeability of a measurement object, it is possible to evaluate the quality of the measurement object, such as the density of the surface layer.

[0015] As shown in Fig. 2, the air permeability measuring device 10 includes an attachment 11, a gasket 12, a cylinder 13, a piston 14, a stopper 15, a pressure sensor 16, and a control device 101. As shown in Fig. 1, the control device 101 includes a first control unit 17, a storage unit 18, and a communication unit 19.

[0016] The attachment 11 is made of, for example, metal, and is a member for arranging the cylinder 13. The attachment 11 is arranged in close contact with the surface of the object to be measured via a gasket 12.

[0017] 2, the attachment 11 has a contact portion 11a, an opening 11b, a cylindrical portion 11c, a mounting portion 11d, and a communication hole 11e. The contact portion 11a is made of, for example, a circular plate-like member. The contact portion 11a contacts the surface of the object to be measured via a gasket 12.

[0018] The opening 11b is formed at the center of the contact portion 11a and has, for example, a circular outer shape when viewed from below in Fig. 2. When measuring the air permeability of a measurement object using the air permeability measuring device 10, the opening 11b is positioned opposite the measurement object. Furthermore, when the cylinder 13 is fixed to the attachment 11, the opening 11b is configured to communicate with the connection hole 13b of the cylinder 13.

[0019] The cylindrical portion 11c is provided so as to protrude from the contact portion 11a on the side opposite to the object to be measured. A cylinder 13 is disposed in the cylindrical portion 11c. The outer peripheral surface of the cylinder 13 fits into the inner peripheral surface of the cylindrical portion 11c.

[0020] Furthermore, a mounting portion 11d is formed on a part of the outer circumferential surface of the cylindrical portion 11c. The mounting portion 11d has, for example, a triangular prism shape. The pressure sensor 16 and the control device 101 are attached to the mounting portion 11d with screws or the like. The shape and location of the mounting portion 11d can be changed as appropriate.

[0021] The mounting portion 11d is provided with a communication hole 11e that communicates with the opening 11b of the attachment 11. The pressure sensor 16 is connected to the communication hole 11e and communicates with the internal space 13a of the cylinder 13 via the opening 11b and the connection hole 13b.

[0022] The gasket 12 is made of, for example, low-hardness silicone and is configured to fit tightly against the surface of the object to be measured. The gasket 12 is disposed between the surface of the object to be measured and the attachment 11 so as to surround the periphery of the opening 11b of the attachment 11, thereby sealing the gap between the surface of the object to be measured and the opening 11b of the attachment 11.

[0023] The material of the gasket 12 may be any material that can ensure airtightness, and may be a gel material or the like in addition to low-hardness silicone. Furthermore, if the attachment 11 itself is configured to be able to adhere well to the surface of the object to be measured, the gasket 12 may be omitted.

[0024] The cylinder 13 is, for example, a cylindrical container. The cylinder 13 has an internal space 13a and a connection hole 13b. The internal space 13a communicates with the opening 11b of the attachment 11 via the connection hole 13b. The cylinder 13 is, for example, a transparent container, and is configured so that the user can visually check the state inside the cylinder 13. Note that a plurality of scales (not shown) are engraved on the outer circumferential surface of the cylinder 13.

[0025] The piston 14 has a piston rod 141, a piston head 142, an engaging protrusion 143, and a handle 144. The piston rod 141 is a rod-shaped member, and is arranged so as to be able to reciprocate along the longitudinal direction of the cylinder 13 (the up-and-down direction in FIG. 2 ).

[0026] A piston head 142 is provided at the end of the piston rod 141 on the attachment 11 side. The piston head 142 is a cylindrical member made of rubber, for example. The piston head 142 is fitted inside the cylinder 13.

[0027] The piston head 142 is disposed so as to be able to slide on the inner circumferential surface 130 of the cylinder 13 along the longitudinal direction of the cylinder 13. When the piston head 142 slides on the inner circumferential surface 130 of the cylinder 13, the volume of the internal space 13a of the cylinder 13 changes.

[0028] An engaging protrusion 143 is provided on the piston head 142 side of the piston rod 141. The engaging protrusion 143 protrudes on both sides in the radial direction (left and right direction in FIG. 2 ) of the cylinder 13. The engaging protrusion 143 engages with an engaging portion 15b of the stopper 15, which will be described later.

[0029] A handle 144 is provided at the end of the piston rod 141 opposite to the piston head 142. The handle 144 is a member that the user of the air permeability measuring device 10 grasps to move the piston 14 when operating the piston 14.

[0030] A stopper 15 is provided at the end of the cylinder 13 opposite to the attachment 11. The stopper 15 is a member for restricting the movement of the piston 14. The stopper 15 has a hole 15a and an engagement portion 15b.

[0031] The hole 15a is a hole for allowing the piston rod 141 and the engaging protrusion 143 to pass through. The engaging portion 15b engages with the engaging protrusion 143 that has passed through the hole 15a. By the engaging protrusion 143 engaging with the engaging portion 15b, the position of the piston head 142 in the longitudinal direction of the cylinder 13 is restricted, and the piston 14 can be maintained in a stopped state.

[0032] The pressure sensor 16 is, for example, a digital pressure gauge. The pressure sensor 16 is capable of detecting pressure values ​​in the range of, for example, -100 to 100 kPa. The pressure sensor 16 has a display unit 16a. The pressure value detected by the pressure sensor 16 is displayed on the display unit 16a.

[0033] The pressure sensor 16 is attached to the mounting portion 11d of the attachment 11 and connected to the communication hole 11e. The pressure sensor 16 detects the pressure value in the internal space 13a of the cylinder 13 via the communication hole 11e and the opening 11b. The pressure sensor 16 displays the detected pressure value in the internal space 13a on the display portion 16a. The pressure sensor 16 also outputs a signal corresponding to the detected pressure value in the internal space 13a to the first control portion 17 (see FIG. 1).

[0034] 1, a first control unit 17 of the control device 101 controls the air permeability measuring device 10. The first control unit 17 is an example of a control unit. The first control unit 17 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc.

[0035] The first control unit 17 calculates the air permeability rate and identifies the air inflow rate corresponding to the calculated air permeability rate. Here, the air permeability rate is an index for evaluating the air permeability of the measurement object. The air inflow rate is the amount of air that flows from the measurement object into the internal space 13a of the cylinder 13 due to the pressure difference when the internal space 13a of the cylinder 13 is depressurized with the attachment 11 in close contact with the surface of the measurement object.

[0036] The first control unit 17 also determines whether or not there is an air leak in the attachment 11. The first control unit 17 transmits information relating to the air permeability rate, the amount of air inflow, and the presence or absence of an air leak, etc., via the communication unit 19 to the transceiver unit 23 of the communication device 20.

[0037] The storage unit 18 is, for example, an auxiliary storage device such as a hard disk drive, etc. The storage unit 18 stores, for example, data relating to the correlation between the air permeation rate and the amount of air inflow.

[0038] The communication unit 19 communicates with the transmission / reception unit 23 of the communication device 20. For example, Bluetooth (registered trademark) can be used as a communication method between the communication unit 19 and the transmission / reception unit 23. Note that other communication methods such as Wi-Fi (registered trademark) may also be used.

[0039] The communication unit 19 transmits data to the communication device 20 to display information regarding the pressure value of the internal space 13a of the cylinder 13 detected by the pressure sensor 16, the air permeability rate calculated by the first control unit 17, and the air inflow amount determined by the first control unit 17.

[0040] The communication device 20 is a mobile terminal such as a smartphone, and is a device capable of communicating with the air permeability measuring device 10. The user is assumed to have installed in advance an application dedicated to pressure measurement in the communication device 20. Note that the communication device 20 is not limited to a mobile terminal, and may also be a personal computer, a tablet terminal, or the like.

[0041] The communication device 20 has a second control unit 21, a second display unit 22, and a transceiver unit 23. The second control unit 21 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc. The second control unit 21 is an example of a control unit. The second display unit 22 displays information transmitted from the communication unit 19 of the air permeability measuring device 10.

[0042] For example, the second display unit 22 displays information about the air permeability rate calculated by the first control unit 17, information about the air inflow amount specified by the first control unit 17, etc. Note that the second display unit 22 may also display information about the pressure value detected by the pressure sensor 16.

[0043] [Air Permeability Measurement Method] Next, an air permeability measurement method using the air permeability measurement device 10 will be described with reference to Figs. 3 to 6. Fig. 3 is a flowchart showing the flow of evaluating the air permeability of a measurement object using the air permeability measurement device 10. Fig. 4 is a diagram showing how the air permeability of concrete C is measured using the air permeability measurement device 10. In the following, the description will continue using the concrete C shown in Fig. 4 as an example of the above-mentioned measurement object. Note that the concrete C is used for bridge piers, etc.

[0044] In the air permeability measurement method using the air permeability measurement device 10, a placement step (S1), a depressurization step (S2), a standby start step (S3), a first measurement step (S4), a second measurement step (S5), a calculation step (S6), an identification step (S7), a display step (S8), and a standby end step (S9) are performed in this order.

[0045] First, the user of the air permeability measuring device 10 connects the pressure sensor 16 to the mounting portion 11d of the attachment 11. Then, the user operates the communication device 20 to start an application dedicated to pressure measurement. Hereinafter, this application will be referred to as "pressure measurement application A."

[0046] Next, in the placement step (S1), the user places the abutment portion 11a of the attachment 11 against the surface of the concrete C, as shown in Figure 4, and places the attachment 11 in close contact with the surface of the concrete C via the gasket 12.

[0047] After the placement step (S1), the user operates the communication device 20 to start measurement in the pressure measurement application A. When the pressure measurement application A starts measurement, the pressure sensor 16 starts detecting the pressure in the internal space 13a of the cylinder 13 and starts counting the elapsed time.

[0048] Before starting measurement in the pressure measurement application A, the type, material, size, and intended use of the object to be measured may be recorded in a database (not shown) via the pressure measurement application A. This makes it possible to easily manage data from measurements using the air permeability measuring device 10.

[0049] Next, in the decompression step (S2), the user grips the handle 144 and applies a pulling force to the piston head 142 on the side opposite to the surface of the concrete C (the right side in Figure 4), moving the piston 14 relative to the cylinder 13. This increases the volume of the internal space 13a of the cylinder 13, and reduces the pressure in the internal space 13a according to Boyle's law.

[0050] After the decompression step (S2), the user passes the engaging protrusion 143 of the piston 14 through the hole 15a of the stopper 15, and then rotates the handle 144 around the axis of the piston rod 141 to engage the engaging protrusion 143 with the engaging portion 15b, thereby fixing the position of the piston 14.

[0051] Then, the user performs a standby start step (S3) in which the user waits for a predetermined time with the piston 14 fixed in a predetermined position. The predetermined time is, for example, 60 seconds (see FIG. 5). The display unit 16a may be configured to display the elapsed time from the start of measurement of the air permeability of the concrete C by the air permeability measuring device 10.

[0052] Fig. 5 is a graph showing the pressure change in the internal space 13a of the cylinder 13 when the air permeability of the concrete C is measured using the air permeability measuring device 10. As shown in Fig. 5, after the depressurization step (S2), the pressure in the internal space 13a of the cylinder 13 is reduced to -90 kPa, and then restored to -70 kPa as air flows into the internal space 13a from the concrete C.

[0053] After the standby start step (S3), in a first measurement step (S4), a first pressure P1, which is the pressure in the internal space 13a of the cylinder 13 at time t1, is detected by the pressure sensor 16. As shown in Fig. 5, the first pressure P1 at time t1 is -86 kPa.

[0054] After the first measurement step (S4), in the second measurement step (S5), a second pressure P2, which is the pressure in the internal space 13a at a predetermined measurement time T after the first measurement step (S4) is performed, is detected by the pressure sensor 16. The measurement time T is, for example, 30 seconds. As shown in FIG. 5, the second pressure P2 is −77 kPa.

[0055] After the second measurement step (S5), in the calculation step (S6), the first control unit 17 calculates the air permeation rate by dividing the pressure difference ΔP obtained by subtracting the first pressure P1 from the second pressure P2 by the measurement time T. The air permeation rate is calculated as {−77−(−86)} / 30=0.30 [kPa / s].

[0056] Next, in the identification step (S7), the first control unit 17 identifies the air inflow amount corresponding to the calculated air permeability rate by referring to the air permeability rate calculated in the calculation step (S6) and the correlation stored in the memory unit 18.

[0057] Here, the correlation stored in the memory unit 18 will be described. FIG. 6 is a diagram showing the correlation between the air permeability rate and the amount of air inflow stored in the memory unit 18. The example shown in FIG. 6 shows the results of an experiment conducted under multiple conditions in which the air permeability rate and the amount of air inflow were measured while maintaining a reduced pressure state for 30 seconds. The multiple conditions include the water-cement ratio W / C, the fine aggregate ratio s / a, and the amount of air-entraining agent. Note that the correlation is not limited to 30 seconds, and may be obtained, for example, for a case in which the pressure is reduced for 10 seconds. Furthermore, the object to be measured in the experiment shown in FIG. 6 is not limited to concrete, and may be made of any material, such as mortar. However, the data is limited to the region in which the pressure change shown in FIG. 5 is linear (the range from t1 to t3 in FIG. 5).

[0058] The air permeation rate is the air permeation rate when the piston 14 is fixed in a predetermined position and maintained for 30 seconds. The air inflow rate is the air inflow rate when the reduced pressure state is maintained for 30 seconds, as read from the scale on the cylinder 13.

[0059] As shown in FIG. 6, the coefficient of determination R ２ = 0.985, which indicates that there is a strong correlation between the air permeation rate and the amount of air inflow. This makes it possible to measure the amount of air inflow from the air permeation rate without reading the scale on the cylinder 13.

[0060] When an approximation line was obtained from the correlation in Fig. 6, the relational expression y = 61.1x + 0.166 was obtained. Hereinafter, this relational expression will be referred to as "relational expression X". Here, y represents the air inflow rate, and x represents the air permeation rate. It is assumed that the relational expression X representing the correlation in Fig. 6 is stored in the memory unit 18. As a result, when the air permeation rate is calculated, the air inflow rate can be uniquely determined by inputting the calculated air permeation rate into x of relational expression X.

[0061] Returning to the description of the air permeability measurement method using the air permeability measurement device 10, in the calculation step S6 described above, the air permeability rate was calculated to be 0.30 kPa / s, so the air inflow rate is determined to be y = 61.1 x 0.30 + 0.166 = 18.5 ml. In this way, the first control unit 17 determines the air inflow rate corresponding to the calculated air permeability rate by referring to the relational expression X (S7: determination step).

[0062] Conventionally, to determine the amount of air inflow, it was necessary to read the amount of air inflow into the internal space 13a of the cylinder 13 when the pressure was restored. This reading of the amount of air inflow was done by visually checking the scale engraved on the cylinder 13. Therefore, in order to reduce reading errors, it is preferable that the amount of air inflow during decompression is large. In other words, it is preferable that the period between decompression and pressure restoration is as long as possible.

[0063] In contrast, according to the air permeability measuring device 10 of this embodiment, the first pressure P1 and the second pressure P2 are detected by the pressure sensor 16, and therefore, even if the difference between the first pressure P1 and the second pressure P2 is small, the detection error for each is significantly smaller than when the air inflow amount is visually read as described above, although this depends on the accuracy of the pressure sensor 16. In other words, the time between the detection of the first pressure P1 and the detection of the second pressure P2 can be shortened.

[0064] After the identification step (S7), the communication unit 19 transmits the first pressure P1 detected by the pressure sensor 16 in the first measurement step (S4), the second pressure P2 detected by the pressure sensor 16 in the second measurement step (S5), the air permeability rate calculated by the first control unit 17 in the calculation step (S6), and the air inflow amount identified by the first control unit 17 to the transceiver unit 23 of the communication device 20.

[0065] Next, in the display step (S8), the first pressure P1 and the second pressure P2 are displayed on the display unit 16a of the pressure sensor 16. In addition, the air permeability rate and the amount of air inflow are displayed on the second display unit 22. Note that the second display unit 22 may display only either the air permeability rate or the amount of air inflow. The user can evaluate the air permeability of the concrete C by checking the air permeability rate or the amount of air inflow displayed on the second display unit 22.

[0066] After the display step (S8), in the standby end step (S9), the user operates the handle 144 to disengage the engaging protrusion 143 of the piston 14 from the engaging portion 15b of the stopper 15, thereby releasing the pulling force on the piston 14.

[0067] As a result, the piston 14 moves toward the concrete C, and the volume of the internal space 13a of the cylinder 13 decreases, causing the pressure in the internal space 13a to increase according to Boyle's law, and then recovers as shown by the pressure change after time t3 in Figure 5.

[0068] After the standby end step (S9), the user operates the communication device 20 to stop measurement in the pressure measurement application A. When measurement is stopped in the pressure measurement application A, the pressure sensor 16 stops detecting the pressure in the internal space 13a, and the counting of the elapsed time is stopped.

[0069] Before the measurement is stopped in the pressure measurement application A, the measurement results such as the air permeability rate and the air inflow rate may be recorded in a database (not shown) via the pressure measurement application A. This makes it possible to manage the measurement results obtained by the air permeability measuring device 10.

[0070] 3, the first control unit 17 concurrently determines whether or not there is an air leak in the attachment 11. Here, FIG. 7 is a flowchart showing the flow of the air leak detection process by the air permeability measuring device 10.

[0071] 7, the first control unit 17 determines whether the calculated air permeation rate is equal to or greater than a predetermined threshold (S11). If the air permeation rate is equal to or greater than the threshold (S11: YES), the first control unit 17 determines that there is an air leak near the attachment 11.

[0072] 8 is a graph showing pressure changes during measurement by the air permeability measuring device 10 when gaskets 12 made of different materials are used. In Fig. 8, silicon A, silicon B, silicon C, and silicon D represent cases where high-hardness silicon is used as the material for the gasket 12. Each high-hardness silicon has different hardness, thickness, etc.

[0073] Low hardness A, low hardness B, low hardness C, and low hardness D indicate cases where low hardness silicone is used as the material for the gasket 12. Each low hardness silicone has a different hardness, thickness, etc. Gel A, gel B, gel C, and gel D indicate cases where a urethane gel gasket 12 is used. Each urethane gel has a different hardness, thickness, etc.

[0074] As shown in Figure 8, when (1) silicone A to D, low hardness D, and gel D were used as the material of the gasket 12, the pressure rose sharply immediately after the start of measurement, and it was found that air leaked near the attachment 11.

[0075] On the other hand, when (2) Low Hardness C and Gel C were used as the material for the gasket 12, the pressure recovery was completed in about 40 seconds. In contrast, when (3) Low Hardness A, Low Hardness B, Gel A, and Gel B were used as the material for the gasket 12, the reduced pressure state could be maintained for about 60 seconds.

[0076] As in the case of (1) above, when the pressure in the internal space 13a of the cylinder 13 rises suddenly, the air permeation rate calculated by dividing the pressure change by the measurement time exceeds a threshold value. When the air permeation rate exceeds the threshold value (S11: YES), the first control unit 17 transmits an error signal to the transceiver unit 23 of the communication device 20 via the communication unit 19.

[0077] When the error signal is received by the transmitter / receiver 23, the second control unit 21 causes the second display unit 22 to display a predetermined error message (S12). By confirming that an error message is displayed on the second display unit 22, the user can quickly understand that air is leaking from around the contact portion 11a of the attachment 11, etc. This allows the user to redo the measurement using the air permeability measuring device 10.

[0078] Effect of First Embodiment According to the air permeability measuring device 10 described above, the first control unit 17 can calculate the air permeability rate by dividing the pressure difference ΔP between the first pressure P1 detected by the pressure sensor 16 in the first measurement step (S4) and the second pressure P2 detected by the pressure sensor 16 in the second measurement step (S5) by the measurement time T (S6: calculation step).

[0079] Then, the first control unit 17 can determine the amount of air inflow by referring to data regarding the correlation between the air permeability rate and the amount of air inflow stored in the memory unit 18, and can evaluate the air permeability of the concrete C, which is the object to be measured.

[0080] On the other hand, in conventional air permeability measuring devices, the inside of the cylinder is decompressed and the device is left standing for a predetermined time (for example, 60 seconds), and then the amount of air that has flowed into the inside of the cylinder is determined by reading the scale on the cylinder.

[0081] In contrast, with the air permeability measuring device 10, after the second measurement step (S5), the amount of air inflow corresponding to the calculated air permeability rate can be immediately determined by referring to the correlation data pre-stored in the memory unit 18, without reading the scale on the cylinder 13. This means that the measurement time using the air permeability measuring device 10 can be reduced to about half (about 30 seconds) of the conventional method, and the air permeability of the concrete C can be evaluated in a short time.

[0082] Furthermore, in a display step (S8), the first control unit 17 displays the first pressure P1 detected in the first measurement step (S4) and the second pressure P2 detected in the second measurement step (S5) on the display unit 16a. Furthermore, the second display unit 22 of the communication device 20 displays the air permeability rate calculated in the calculation step (S6) and the air inflow rate identified in the identification step (S7). This allows the user to quickly grasp the air inflow rate by visually checking the second display unit 22 of the communication device 20, without having to read the scale on the cylinder 13.

[0083] Furthermore, since the air permeability measuring device 10 is not a device that reduces pressure using a vacuum pump or the like, it does not require a power source to drive a vacuum pump or the like, and can evaluate the air permeability of the surface layer of concrete C with an inexpensive and simple configuration.

[0084] Furthermore, in the placement step (S1), the attachment 11 can be placed in close contact with the surface of the concrete C, which is the object to be measured, via the gasket 12, so that the air permeability of the concrete C can be evaluated well using the air permeability measuring device 10.

[0085] In addition, the pressure sensor 16 is attached to the mounting portion 11d of the attachment 11 and connected to a communication hole 11e that communicates with the internal space 13a of the cylinder 13 and the opening 11b of the attachment 11, so that the pressure sensor 16 can be stably positioned and the pressure in the internal space 13a of the cylinder 13 can be accurately detected.

[0086] Furthermore, data relating to the correlation between the air permeability rate and the amount of air inflow is pre-stored in the memory unit 18, so after the air permeability rate is calculated by the first control unit 17, the amount of air inflow corresponding to the calculated air permeability rate can be quickly identified by referring to the data.

[0087] 3, the first control unit 17 concurrently determines whether or not there is an air leak in the attachment 11, and if the air permeability rate is equal to or greater than a predetermined threshold (S11: YES), it determines that there is an air leak, and an error message is displayed on the second display unit 22 (S12). After confirming the error message, the user can restart the air permeability measurement using the air permeability measuring device 10 from the placement step (S1), thereby making it possible to properly evaluate the air permeability of the object to be measured.

[0088] Furthermore, since the first measurement step (S4) and the second measurement step (S5) are performed before the standby end step (S9), the measurement time T can be shortened.

[0089] The communication unit 19 of the air permeability measuring device 10 transmits information relating to the pressure in the internal space 13a of the cylinder 13 detected by the pressure sensor 16, the air permeability rate calculated by the first control unit 17, and the air inflow rate specified by the first control unit 17 to the transceiver unit 23 of the communication device 20. The second display unit 22 displays the information transmitted from the communication unit 19. This allows the user to quickly understand the measurement results by visually checking the second display unit 22 of the communication device 20.

[0090] [Embodiment 2] Next, embodiment 2 of the present disclosure will be described with reference to Fig. 9. For convenience of explanation, members having the same functions as those described in embodiment 1 above will be denoted by the same reference numerals, and their description will not be repeated. Fig. 9 is a block diagram showing the configuration of an air permeability measuring device 10A according to embodiment 2.

[0091] As shown in Fig. 9, the air permeability measuring device 10A includes a pressure sensor 16, a control device 101A, and a first display unit 102. The control device 101A has a first control unit 17 and a storage unit 18. In the second embodiment, instead of displaying the air permeability rate and the air inflow rate on the second display unit 22 of the communication device 20, the air permeability rate and the air inflow rate are displayed on the first display unit 102 of the air permeability measuring device 10A.

[0092] The air permeability measuring device 10A includes an attachment 11, a gasket 12, a cylinder 13, a piston 14, and a stopper 15 (see FIG. 2 ), similar to the air permeability measuring device 10 of the first embodiment. Note that the air permeability measuring device 10A is not configured to be able to communicate with the communication device 20.

[0093] The first display unit 102 is separate from the pressure sensor 16 and is a dedicated display for displaying the measurement results obtained by the air permeability measuring device 10A. The first display unit 102 is configured by a liquid crystal display (LCD; Liquid Crystal Display), an organic EL (Electro-Luminescence) display, or the like.

[0094] The first display unit 102 is connected to the first control unit 17 via wired communication or wireless communication. The first display unit 102 displays the air permeation rate and the air inflow rate calculated by the first control unit 17. Note that a plurality of first display units 102 may be installed.

[0095] The air permeability measuring device 10A of the second embodiment described above can also achieve the same effects as the air permeability measuring device 10 of the first embodiment. In particular, even if the user does not carry the communication device 20, the user can evaluate the air permeability of the concrete C in a short period of time by visually checking the first display unit 102.

[0096] [Other Embodiments] In the air permeability measuring device 10 of the first embodiment described above, the air permeability rate and the air inflow rate are displayed on the second display unit 22 of the communication device 20, but this is not limited to this. The air permeability measuring device 10 may be provided with a first display unit separate from the pressure sensor 16, and the air permeability rate and the air inflow rate may be displayed on both the first display unit and the second display unit 22.

[0097] In the first and second embodiments described above, the piston 14 is fixed by engaging the engaging protrusion 143 of the piston rod 141 with the hole 15a of the stopper 15. However, the present invention is not limited to this. For example, a recess may be provided in the piston rod 141 and a protrusion may be provided in the stopper 15, and the protrusion of the stopper 15 may be engaged with the recess of the piston rod 141.

[0098] Furthermore, in the above-described first and second embodiments, the user operates the handle 144 to move the piston 14 relative to the cylinder 13, but this is not limiting. For example, the air permeability measuring device 10 may be provided with an actuator that moves the handle 144 along the longitudinal direction of the cylinder 13. In this case, the communication device 20 controls the first control unit 17 via the communication unit 19, thereby remotely operating the actuator to move the piston 14 relative to the cylinder 13.

[0099] In the first embodiment described above, the first control unit 17 calculates the air permeability rate and identifies the air inflow rate corresponding to the calculated air permeability rate, but this is not limiting. For example, the pressure value detected by the pressure sensor 16 may be transmitted to the communication device 20 via the communication unit 19, and the second control unit 21 of the communication device 20 may calculate the air permeability rate and identify the air inflow rate. The second display unit 22 displays the air permeability rate calculated by the second control unit 21 and the air inflow rate identified by the second control unit 21.

[0100] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure.

[0101] REFERENCE SIGNS LIST 10 Air permeability measuring device 10A Air permeability measuring device 11 Attachment 11a Contact portion 11b Opening 11e Communication hole 12 Gasket 13 Cylinder 13a Internal space 14 Piston 16 Pressure sensor 17 First control unit 18 Memory unit 19 Communication unit 20 Communication device 21 Second control unit 22 Second display unit 100 Air permeability measuring system 102 First display unit

Claims

1. An attachment disposed on a surface of an object to be measured and having an opening facing the object to be measured; a cylinder having an internal space communicating with the opening of the attachment and fixed to the attachment; a piston that changes the volume of the internal space by sliding on the inner circumferential surface of the cylinder; a pressure sensor that detects the pressure of the internal space through the opening of the attachment; and a control unit, wherein the control unit calculates a pressure difference between a first pressure, which is the pressure of the internal space at a certain time after pressure reduction is achieved by applying a tensile force to the piston, and a second pressure, which is the pressure of the internal space after a predetermined measurement time has elapsed since the first pressure was detected, with the attachment in close contact with the surface of the object to be measured, and calculates an air permeability rate, which is an index for evaluating the air permeability of the object to be measured, by dividing the pressure difference by the measurement time; and specifies the air inflow rate corresponding to the air permeability rate by referring to the correlation between the calculated air permeability rate and an air inflow rate, which is the inflow rate of air that flows into the internal space as the internal space is reduced in pressure. An air permeability measuring device.

2. The air permeability measuring device according to claim 1, further comprising a first display unit that displays information relating to at least one of the pressure in the internal space detected by the pressure sensor, the air permeability rate calculated by the control unit, and the air inflow amount specified by the control unit.

3. The air permeability measuring device according to claim 1, further comprising a gasket disposed between the surface of the object to be measured and the attachment, the gasket being in intimate contact with the surface of the object to be measured, the attachment being disposed in intimate contact with the surface of the object to be measured via the gasket.

4. The air permeability measuring device according to claim 1, characterized in that the attachment has a communication hole on its outer circumferential surface that communicates with the opening, and the pressure sensor is connected to the communication hole of the attachment.

5. The air permeability measuring device according to claim 1, further comprising a storage unit in which data relating to said correlation is stored.

6. The air permeability measuring device according to claim 1, further comprising a communication unit that transmits information relating to at least one of the pressure in the internal space detected by the pressure sensor, the air permeability rate, and the amount of air inflow to a communication device, wherein the communication unit transmits data to the communication device for causing the communication device to display the information.

7. The air permeability measuring device according to claim 1, characterized in that the control unit further determines that there is an air leak when the calculated air permeability rate is equal to or greater than a predetermined threshold value.

8. An air permeability measuring method using the air permeability measuring device according to any one of claims 1 to 7, comprising: a positioning step of positioning the attachment on a surface of the object to be measured; a depressurizing step of applying the tensile force to the piston to slide the piston to depressurize the internal space of the cylinder; a standby start step of starting standby after the depressurizing step with the piston fixed in a predetermined position; a first measurement step of detecting a first pressure, which is the pressure in the internal space at a certain time after the standby start step, with the pressure sensor; a second measurement step of detecting a second pressure, which is the pressure in the internal space when the measurement time has elapsed since the first measurement step was performed, with the pressure sensor after the standby start step; a calculation step of calculating the air permeability rate by dividing the pressure difference, which is the difference between the second pressure and the first pressure, by the measurement time with the control unit; and a determination step of determining an air inflow rate corresponding to the air permeability rate by referring to a correlation between the air permeability rate calculated by the control unit and an air inflow rate, which is the inflow rate of air flowing into the internal space as the internal space is depressurized. A method for measuring air permeability comprising the steps of:

9. The air permeability measurement method according to claim 8, further comprising a display step of displaying on a first display unit information relating to at least one of the pressures detected in the first measurement step and the second measurement step, the air permeability rate calculated in the calculation step, and the air inflow amount identified in the identification step.

10. The air permeability measurement method according to claim 8, further comprising a standby end step of releasing the fixation of the piston after the standby start step, and the first measurement step and the second measurement step are performed before the standby end step.

11. An air permeability measurement system comprising: an air permeability measurement device according to any one of claims 1 to 7; and a communication device capable of communicating with said air permeability measurement device, wherein said air permeability measurement device further comprises a communication unit which transmits to said communication device information relating to at least one of the pressure in said internal space detected by said pressure sensor, the air permeability rate calculated by said control unit, and the air inflow amount specified by said control unit, and wherein said communication device has a second display unit which displays the information transmitted from the communication unit.

12. An air permeability measuring device comprising: an attachment disposed on a surface of an object to be measured and having an opening facing the object to be measured; a cylinder having an internal space communicating with the opening of the attachment and fixed to the attachment; a piston which changes the volume of the internal space by sliding on the inner circumferential surface of the cylinder; and a pressure sensor which detects the pressure of the internal space via the opening of the attachment; and a communication device capable of communicating with the air permeability measuring device, wherein the air permeability measuring device further comprises a communication section which transmits information regarding the pressure of the internal space detected by the pressure sensor to the communication device, the communication device having a control section and a second display section, wherein the control section calculates a pressure difference between a first pressure which is the pressure of the internal space at a certain time after the pressure is reduced by applying a tensile force to the piston with the attachment in close contact with the surface of the object to be measured, and a second pressure which is the pressure of the internal space after a predetermined measurement time has elapsed since the first pressure was detected, an air permeability measurement system comprising: a pressure difference divided by the measurement time to calculate an air permeability rate, which is an index for evaluating the air permeability of the object to be measured; and a correlation between the calculated air permeability rate and an air inflow rate, which is the amount of air flowing into the internal space as the internal space is depressurized, to identify the air inflow rate corresponding to the air permeability rate; and a second display unit displays information relating to the air permeability rate calculated by the control unit and the air inflow rate identified by the control unit.

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