JP2009222509A - Concrete evaluation device and concrete evaluation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concrete evaluation device which is reduced in measurement errors of the moisture content and the dispersion in the measured values, caused by a change in the density of concrete and capable of measuring the amount of moisture in concrete by a simple constitution, and to provide a concrete evaluation method. <P>SOLUTION: In the concrete evaluation device 10, the humidity of the internal space 1a of a pressure-resistant container 1 in either one of an initial state before the internal space 1a is reduced in pressure by a pressure-reducing member 2 and a reduced pressure state and the humidity of the internal space 1a, in the degree-of-reduced pressure lowered state lowered in the degree of reduced pressure of the internal space 1a from the reduced pressure state by the natural suction of air are measured, and the moisture content in concrete 11 is evaluated by these humidities. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a concrete evaluation apparatus and a concrete evaluation method.

  Synthetic resins such as epoxy resin, urethane resin, methacrylic resin, polyester resin, vinyl ester resin, and acrylic resin are used as the painted floor, and can be applied to various factories, offices, warehouses, corridors, kitchens, and laboratories, both indoors and outdoors. And shared. When constructing these coating floor materials, various management during construction is important in order to prevent problems after construction such as swelling and peeling.

  In particular, quality control of the substrate that is the target of application is important. In the “Coating Floor Handbook” edited by the Japan Paint Floor Industry Association, the degree of drying of the substrate, surface strength, compressive strength, flatness, smoothness, dirt, etc. It is described that it is necessary to manage the ground condition of the paper.

  In addition, the Japan Floor Construction Technology Research Council has developed a method for measuring various grades and grades of the surface layer of the concrete floor surface, and presents the ground surface evaluation method. The evaluation items include surface irregularities, unevenness, surface strength, and moisture content. (Surface layer part), water content (up to about 40 mm from the surface), and a measuring method for each item is presented. Among them, dryness test paper is used for measuring the moisture content of the surface layer portion. In the measurement using the dryness test paper, a color evaluation value is determined by the degree of discoloration in the dryness test.

  In addition, for the measurement of water content from the surface to about 40 mm, measurement by a high-frequency capacitance moisture meter HI-500 or HI-520 for concrete and mortar (manufactured by Kett Science Laboratory) is presented. In addition, a moisture content of 5% or less as the degree of dryness of the base is regarded as a workable moisture content. In many cases, the measured value by this moisture meter is used as an index even at the floor construction site. The moisture meter is a device that presses an electrode against a concrete surface and measures moisture by an electric current as disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-153781.

As an apparatus for measuring moisture, there is also an apparatus described in, for example, Japanese Patent Application Laid-Open No. 11-006797. Japanese Patent Application Laid-Open No. 11-006797 discloses an apparatus for irradiating concrete with infrared rays and obtaining moisture of the concrete from the amount of reflected infrared rays.
JP 2006-153781 A JP-A-11-006797

  However, in the measurement of the moisture content using the dryness test paper, there is a problem that the error becomes large because the color evaluation value is obtained by the degree of color change of the dryness test paper.

  In addition, when measuring the amount of water using the above high-frequency capacitance moisture meter, the display value may vary greatly due to the difference in the contact area due to the difference in density of the underlying concrete against which the + electrode is pressed, or it may exist inside the concrete. There is a problem such as being unable to detect the moisture to be.

  Further, in the above moisture meter, in order to measure the moisture content in both the shallow portion and the deep portion of the concrete, it is necessary to prepare a plurality of electrode pairs having different distances between the + electrode and the − electrode. For this reason, the moisture content inside the concrete cannot be measured with a simple device configuration.

  In the apparatus disclosed in Japanese Patent Application Laid-Open No. 11-006797, moisture existing in the concrete cannot be detected, and in order to detect the moisture in the concrete, it is necessary to form a measurement window so as to penetrate into the concrete.

  The present invention has been made in view of the above-mentioned problems, and its purpose is that the error in measuring the moisture content is small, the variation in measured values due to changes in the density of the concrete is small, and the moisture content in the concrete is simplified. It is to provide a concrete evaluation apparatus and a concrete evaluation method that can be measured with a simple configuration.

  The concrete evaluation apparatus of the present invention includes a pressure vessel, a decompression member, and a humidity measurement member. The pressure vessel has an internal space that communicates with the outside. The decompression member is for decompressing the internal space of the pressure vessel. The humidity measuring member is for measuring the humidity of the internal space of the pressure vessel. The humidity measurement member has a reduced humidity level in the internal space in the initial state before the internal space is decompressed by the decompression member and in a decompressed decompressed state, and the degree of decompression of the internal space due to natural intake from the decompressed state. The humidity of the internal space in the reduced pressure reduction state can be measured.

The concrete evaluation method of the present invention includes the following steps.
First, the pressure vessel is brought into an initial state in close contact with the surface of the concrete so that the opening in the internal space of the pressure vessel is sealed with concrete. From the initial state, the internal space is depressurized to a depressurized state. From the depressurized state, the degree of decompression of the internal space is reduced by natural intake, and the internal space is brought into a state of reduced decompression. The amount of moisture in the concrete is evaluated based on the humidity difference between the humidity of the internal space in either the initial state or the reduced pressure state and the humidity of the internal space in the reduced pressure reduction state.

  According to the concrete evaluation apparatus and the concrete evaluation method of the present invention, the internal space formed by the concrete surface and the pressure vessel having an internal space communicating with the outside is brought into a reduced pressure state, whereby moisture contained in the concrete is removed. It can be pulled out of the concrete in an accelerated manner. As a result, the moisture that has flowed out from the inside of the concrete can be measured by the humidity measuring member, and the water present in the concrete can be detected with a small error.

  Moreover, in the concrete evaluation apparatus and the concrete evaluation method of the present invention, the display value does not vary greatly due to the difference in contact area between the apparatus and the concrete as in the conventional example. For this reason, the dispersion | variation in the measured value by the change of the density of concrete can be suppressed small.

  Preferably, the concrete evaluation apparatus further includes a pressure measuring member for measuring the pressure in the internal space of the pressure vessel.

  By measuring the pressure in the internal space of the pressure vessel with this pressure measuring member, the air permeability of the concrete can be measured. Based on the moisture content and air permeability measured above, it is possible to predict the occurrence of swelling and peeling off the flooring material applied to the concrete surface.

  In addition, since one device to which a pressure measuring member for measuring the pressure in the internal space of the pressure vessel is added can measure both the water content and the air permeability at once, the device for measuring the water content and the device for measuring the air permeability The apparatus configuration can be simplified as compared with the case of measuring with a separate apparatus.

  Preferably, the concrete evaluation apparatus further includes a seal member for bringing the pressure vessel into close contact with the surface of the concrete so that the internal space is sealed with concrete so that the opening communicating with the outside of the pressure vessel is sealed with concrete.

  Thereby, it becomes possible to measure the humidity or pressure in the internal space of the pressure vessel more accurately.

  In the concrete evaluation method of the present invention described above, preferably, the time required for the concrete to pass through is measured by measuring the time from the reduced pressure state to the reduced pressure reduction state and the pressure in each of the internal spaces of the reduced pressure state and the reduced pressure reduction state. A step of evaluating temper is further provided.

  Thereby, generation | occurrence | production of the swelling and peeling which arise in the flooring constructed | assembled on the surface of concrete can be estimated with the moisture content and air permeability which were measured above.

  In addition, it is possible to measure both the amount of moisture and air permeability in a single depressurization-depressurization process by a single device with a pressure measuring member that measures the pressure in the internal space of the pressure vessel. The measurement process can be simplified as compared with the case where the measurement of air permeability and the measurement of air permeability are performed in separate processes.

  As described above, according to the present invention, the internal space is formed by a pressure-resistant container having an internal space that allows moisture contained in the concrete to communicate with the concrete surface and the outside in a reduced pressure state. The moisture present in the concrete can be detected with a small error. Further, since there is no large variation in the displayed value due to the difference in the contact area between the apparatus and the concrete, it is possible to suppress the variation in the moisture measurement value in the concrete due to the change in the density of the concrete.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing a configuration of a concrete evaluation apparatus according to an embodiment of the present invention. Referring to FIG. 1, a concrete evaluation apparatus 10 according to the present embodiment includes a pressure vessel 1, a decompression member 2, a humidity measurement member 3, a pressure measurement member 4, a seal member 5, and a logger (automatic recording member). ) 6, pressure hose 7, and rubber plug 8.

The pressure vessel 1 has an internal space 1 a and an opening 1 b for allowing the internal space 1 a to communicate with the outside of the pressure vessel 1. The pressure vessel 1 has, for example, three ports 1c ₁ , 1c ₂ , and 1c ₃ communicating with the internal space 1a. The pressure-resistant container 1 may be any container that can withstand a degree of decompression (for example, 8.0 kPa) as will be described later, and may be made of, for example, pressure-resistant glass, plastic, metal, or the like.

The decompression member 2 is for decompressing the interior space 1 a of the pressure vessel 1 and is connected to the pressure vessel 1 via the pressure hose 7. The pressure hose 7 is airtightly connected to the mouth 1 c ₁ of the pressure vessel 1. For the decompression member 2, for example, a vacuum pump is used. This vacuum pump may be either a wet pump or a dry pump. As the wet pump, a rotary pump, a diffusion pump, an oscillating piston pump, etc. are used. As a dry pump, a sorption pump, a turbo molecular pump, an ion pump, Getter pumps, cryopumps, mechanical booster pumps, diaphragm pumps, and the like are used. Moreover, as the decompression member 2, these pumps may be used alone or in any combination depending on the degree of vacuum.

The humidity measuring member 3 is for measuring the humidity in the internal space 1 a of the pressure vessel 1 and is inserted into the internal space 1 a from the mouth 1 c ₂ of the pressure vessel 1. Further, by the rubber plug 8 is fitted between the humidity measurement member 3 and the mouth 1c _2, airtightness between the humidity measurement member 3 and the mouth 1c ₂ is maintained. For the humidity measuring member 3, for example, a telescopic hygrometer or an electric hygrometer is used alone or in combination.

  Further, as the humidity measuring member 3, for example, a hygroscopic agent having hygroscopicity such as silica gel, molecular sieve (zeolite), aluminum oxide, calcium chloride, magnesium chloride, sodium hydroxide, water absorbent resin (water absorbent polymer) may be used. . That is, after the moisture in the internal space 1a of the pressure vessel 1 is absorbed by the hygroscopic agent, the amount of moisture absorbed in the hygroscopic agent is measured, so that the measured moisture content in the internal space 1a is measured. Humidity may be required. However, when such a hygroscopic agent is used, it is difficult to measure the humidity in a reduced pressure state, so the actual judgment is made based on the humidity measurement result in the initial state.

  The humidity measuring member 3 may be a temperature / humidity sensor that can measure not only humidity but also temperature.

  A logger (automatic recording member) 6 is connected to the humidity measuring member 3. The logger 6 can automatically record the humidity and temperature in the internal space 1a of the pressure vessel 1 measured by the humidity measuring member 3.

Pressure measuring member 4 is for measuring the pressure in the inner space 1a of the pressure vessel 1, is connected to the mouth 1c ₃ of pressure vessel 1 while keeping the airtightness. Thereby, the pressure in the internal space 1 a of the pressure vessel 1 can be measured by the pressure measuring member 4. As the pressure measuring member 4, for example, a Bourdon tube pressure gauge, a diaphragm pressure gauge, or the like may be used alone or in combination.

  The seal member 5 is attached to the pressure vessel 1 so as to surround the opening 1b of the pressure vessel 1. The seal member 5 is configured so that the pressure vessel 1 can be brought into close contact with the surface of the concrete 11, whereby the opening 1 b of the internal space 1 a can be sealed with the concrete 11. The internal space 1a sealed with can be formed. The seal member 5 includes, for example, an O-ring, rubber packing, rubber sheet, metal sheet, semi-metal sheet, seal tape, liquid seal, mechanical seal, etc., and the material thereof is a polymer elastic member, an elastomer member, a rubber member , A polymer gel-like member, for example, obtained from polyurethane or silicon. As a commercial product, α-gel (Geltec Co., Ltd. product) or the like is used.

  In addition, when the pressure-resistant container 1 itself can be arrange | positioned with sufficient adhesiveness directly on the surface of the concrete 11, the sealing member 5 may be abbreviate | omitted. The seal member 5 may not be attached to the pressure vessel 1 in advance, and may be disposed between the pressure vessel 1 and the concrete 11 when evaluating the concrete 11.

  Next, the concrete evaluation method of the present embodiment using the concrete evaluation apparatus 10 will be described.

  FIG. 2 is a flowchart showing a concrete evaluation method according to an embodiment of the present invention. Referring to FIG. 2, first, concrete evaluation apparatus 10 shown in FIG. 1 is installed on the surface of concrete 11 (step S1). During the installation, the pressure-resistant container 1 is arranged so that the seal member 5 is positioned between the pressure-resistant container 1 and the concrete 11 and is in close contact with the surface of the concrete 11. Thereby, the opening 1b of the internal space 1a is sealed with the concrete 11. This state is the initial state. The humidity in the internal space 1a of the pressure vessel 1 in this initial state is measured by the humidity measuring member 3 (step S2).

  From this initial state, the internal space 1a of the pressure-resistant container 1 is decompressed by the decompression member 2 (step S3). This state is a reduced pressure state. The humidity in the internal space 1a of the pressure-resistant container 1 in this reduced pressure state is measured by the humidity measuring member 3, and the pressure in the internal space 1a is measured by the pressure measuring member 4 (step S4). This reduced pressure state is a state in which the internal space 1a is preferably set to 5 to 20 kPa when measured by the pressure measuring member 4.

  The decompression by the decompression member 2 is stopped from this decompressed state. Thereby, air gradually flows into the internal space 1 a of the pressure resistant container 1 through the gaps of the concrete 11. Such natural intake gradually reduces the degree of decompression of the internal space (step S5). This state is a reduced pressure reduction state. The humidity in the internal space 1a of the pressure-resistant container 1 in the reduced pressure reduction state is measured by the humidity measuring member 3, and the pressure in the internal space 1a is measured by the pressure measuring member 4 (step S6).

  Based on the humidity difference between the humidity of the internal space 1a in the initial state and the reduced pressure state and the humidity of the internal space 1a in the reduced pressure reduction state, the moisture content inside the concrete 11 is evaluated. (Step S7A). This reduced pressure reduction state is preferably a state of 30 to 60 kPa when the internal space 1a is measured by the pressure measuring member 4.

  Further, by measuring the time T from the reduced pressure state to the reduced pressure degree state, the pressure P1 of the internal space 1a in the reduced pressure state, and the pressure P2 of the inner space 1a in the reduced pressure degree state, the penetration of the concrete 11 is measured. Temper is evaluated (step S7B). As an air permeability index (A.P.I. (Air Permeability Indexes): unit (kPa / sec.)) For evaluating air permeability, for example, an equation of (P2-P1) / T is used.

  In the present embodiment, the moisture content and air permeability of the concrete are evaluated as described above.

  Note that the humidity and pressure in the internal space 1a may be sequentially measured every predetermined time (for example, every second) from the initial state to the end of the measurement. Further, the temperature in the internal space 1a may be measured by a temperature / humidity sensor as the humidity measuring member 3, and this temperature is also sequentially measured every predetermined time (for example, every second) from the initial state to the end of the measurement. May be. The humidity and temperature thus sequentially measured may be automatically recorded in the logger 6, and the humidity and temperature in the initial state, the reduced pressure state, and the reduced reduced pressure state may be determined from the recorded data. Further, the pressure may be automatically recorded, and the pressure in the initial state, the reduced pressure state, and the reduced pressure reduction state may be determined from the recorded data.

  According to the present embodiment, the moisture contained in the concrete 11 can be pulled out of the concrete 11 in an accelerated manner by making the surface of the concrete 11 in a reduced pressure state. As a result, the moisture that has flowed out from the inside of the concrete 11 can be measured by the humidity measuring member 3 as the humidity, and the moisture present in the concrete 11 can be detected with a small error.

  Further, according to the present embodiment, the display value does not vary greatly due to the difference in the contact area between the apparatus and the concrete 11 as in the conventional example. For this reason, the dispersion | variation in the measured value by the change of the density of the concrete 11 can be suppressed small.

  Moreover, from the moisture content and air permeability of the concrete obtained as described above, it is also possible to predict and evaluate more easily the occurrence of swelling and peeling of the floor material applied on the concrete surface than the conventional example. This will be described below.

  Conventionally, when the moisture content of concrete is measured with a high-frequency capacitance moisture meter HI-500 or HI-520, even if the measured value is 5% or less, which is considered to be a workable moisture content, it is applied after construction. There may be swelling and peeling on the floor surface. The cause of this swelling and peeling is presumed to be due to the pushing-up due to the moisture in the base. However, in the measurement by the conventional moisture meter, it is difficult to estimate the occurrence of the swelling or peeling in advance because the total amount of moisture from the shallow part to the deep part inside the concrete cannot be measured.

  On the other hand, according to the evaluation method using the concrete evaluation apparatus 10 of the present embodiment, the moisture present in the concrete 11 can be detected with a small error as described above. For this reason, it becomes possible to predict the pushing-up of the concrete 11 due to the base moisture more accurately than the conventional example. Therefore, it becomes possible to evaluate more easily the occurrence of swelling and peeling on the surface of the concrete 11 than the conventional example.

  Further, in the case of a conventional measuring device that measures only air permeability, if moisture is present in the voids of the concrete at the time of measuring air permeability, a measurement result is obtained as if the air permeability is low. On the other hand, in the present embodiment, since the moisture content in the voids of the concrete can be evaluated from the measured humidity value, the air permeability can be known more accurately from the moisture content.

  Moreover, in the concrete evaluation apparatus 10 of this Embodiment, both the air permeability of concrete and a moisture content can be measured at once with one apparatus. For this reason, an apparatus structure can be simplified rather than the structure which measures a moisture content and air permeability with a separate apparatus.

  Moreover, in the concrete evaluation method of this Embodiment, both a moisture content and air permeability can be measured by one decompression-decompression degree reduction process. For this reason, a measurement process can be simplified rather than the method of measuring a moisture content and air permeability by a separate process.

  Further, since the pressure resistant container 1 can be brought into close contact with the surface of the concrete 11 by the seal member 5, it is possible to measure the humidity or pressure in the internal space 1a of the pressure resistant container 1 more accurately.

  Further, by measuring the temperature, it is possible to know how the temperature is lowered by the heat of vaporization when the water in the concrete is vaporized. For this reason, it is possible to know the moisture content inside the concrete even from the state of the temperature drop, and it becomes possible to measure the moisture content more accurately.

  As described above, according to the present embodiment, it is possible to easily measure the density of the concrete surface and the presence or absence of moisture inside the concrete at a construction site in a short time. Moreover, the water | moisture content inside the concrete 11 resulting from the malfunction after construction is detectable by whether the humidity of the internal space 1a of the pressure vessel 1 rises more than the humidity in the initial air.

Examples of the present invention will be described below.
Example 1
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  JIS A-5371 concrete pavement board 11 (30 cm × 30 cm) was prepared, and this concrete pavement board 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 50% for one day. After that, the pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 50%.

  The internal space 1a of the pressure vessel 1 was depressurized by the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. The humidity in the internal space 1a in the decompressed state when the decompression was stopped was 26%.

  After the decompression was stopped, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gap of the concrete pavement plate 11 or the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. In this case, A.P.I. is (53.3-8.0) / 206 seconds = 0.22 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state was stabilized at 32%.

  From the above measurement results, the difference in humidity between the initial state and the reduced pressure reduction state was as low as -18%, so that the concrete pavement plate 11 can be determined to be dry concrete containing almost no moisture inside.

  In addition, after drying for 60 hours at 80 ° C., the surface moisture of the concrete pavement plate 11 left in a room at a temperature of 23 ° C. and a humidity of 50% for one day was measured as a high-frequency capacitance moisture meter HI-500 (Kett Scientific Research). The measured value of water content was 3.0%.

  From this result, the concrete pavement board 11 was judged to be the amount of water that can be applied in the coating floor as described in the coating floor handbook issued by the Coating Floor Industry Association.

(Example 2)
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  JIS A-5371 concrete pavement board 11 (30 cm × 30 cm) was prepared, and this concrete pavement board 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 50% for one day. Thereafter, 5 g of tap water was poured from the surface of the concrete pavement plate 11, and after 5 minutes, moisture on the surface of the concrete pavement plate 11 was wiped off with a waste cloth. After that, it was allowed to stand for another hour, and it was confirmed that the surface layer water was scattered and the surface state of the concrete pavement plate 11 was visually the same as the state before flowing water.

  The moisture content on the surface of the concrete pavement board 11 in this state was 3.0% when measured using a high frequency capacitance moisture meter HI-500 (manufactured by Kett Science Laboratory).

  The pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 50%.

  The internal space 1a of the pressure vessel 1 was depressurized by the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. When the decompression was stopped, the humidity in the internal space 1a in the decompressed state was 35%.

  After the decompression was stopped, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gap of the concrete pavement plate 11 or the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. In this case, A.P.I. is (53.3-8.0) / 205 seconds = 0.22 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state increased to 71%.

  From the above measurement results, the humidity difference between the initial state and the reduced pressure reduction state was a high value of + 21%, so that the concrete pavement plate 11 of this example has moisture in the interior as compared with Example 1 above. It can be judged that it contains a lot.

  On the other hand, in view of the fact that the measured value of moisture with the high frequency capacitance moisture meter HI-500 was the same as that of Example 1, by using the apparatus 10 of the present embodiment shown in FIG. It can be seen that the presence of internal moisture that could not be detected by the high frequency capacitance moisture meter HI-500 could be determined.

(Example 3)
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  JIS A-5371 concrete pavement board 11 (30 cm × 30 cm) was prepared, and this concrete pavement board 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 50% for one day. After that, the pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 50%.

  The internal space 1a of the pressure vessel 1 was depressurized by the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. When the decompression was stopped, the humidity in the internal space 1a in the decompressed state was 28%.

  After the decompression was stopped, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gap of the concrete pavement plate 11 or the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. At this time, A.P.I. is (53.3-8.0) / 302 seconds = 0.15 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state was stabilized at 35%.

  From the above measurement results, the difference in humidity between the initial state and the reduced pressure reduction state was as low as -15%, so it can be determined that the concrete pavement plate 11 is dry concrete containing almost no moisture inside.

  In addition, after drying for 60 hours at 80 ° C., the surface moisture of the concrete pavement plate 11 left in a room at a temperature of 23 ° C. and a humidity of 50% for one day was measured as a high-frequency capacitance moisture meter HI-500 (Kett Scientific Research). The measured value of the water content was 3.8%.

  From this result, the concrete pavement board 11 was judged to be the amount of water that can be applied in the coating floor as described in the coating floor handbook issued by the Coating Floor Industry Association.

  However, even in the case of this example, which was dried under exactly the same conditions using the same JIS concrete pavement plate 11 as in Example 1 and measured under the same conditions, measurement with a high frequency capacitance moisture meter HI-500 The result was as high as 0.8%, showing a large variation. Specifically, it can be seen that the ratio of the large value to the small value of the moisture amount in Examples 1 and 3 (large value / small value) is 3.8 / 3.0≈127% and the variation becomes large. On the other hand, it can be seen that the ratio of the large value to the small value of the humidity (large value / small value) in each of the reduced pressure reduction states of Examples 1 and 3 is 35/32 = 109%, and the variation is small. .

Example 4
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  JIS A-5371 concrete pavement board 11 (30 cm × 30 cm) was prepared, and this concrete pavement board 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 50% for one day. Thereafter, 10 g of tap water was poured from the surface of the concrete pavement plate 11, and after 5 minutes, moisture on the surface of the concrete pavement plate 11 was wiped off with a waste cloth. After that, it was allowed to stand for another hour, and it was confirmed that the surface layer water was scattered and the surface state of the concrete pavement plate 11 was visually the same as the state before flowing water.

  When the moisture content on the surface of the concrete pavement plate 11 in this state was measured using a high frequency capacitance moisture meter HI-500 (manufactured by Kett Science Laboratory), it was 3.8%.

  The pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 50%.

  The internal space 1a of the pressure vessel 1 was depressurized using the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. When the decompression was stopped, the humidity in the internal space 1a in the decompressed state was 42%.

  After the decompression was stopped, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gap of the concrete pavement plate 11 or the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. At this time, A.P.I. is (53.3-8.0) / 302 seconds = 0.15 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state increased to 93%.

  From the above measurement results, the humidity difference between the initial state and the reduced pressure reduction state was a high value of + 43%. Therefore, compared to Example 3 above, the concrete pavement plate 11 of this example has moisture inside. It can be judged that it contains a lot.

  On the other hand, in view of the fact that the measured value of moisture with the high-frequency capacitance moisture meter HI-500 was the same as that of Example 3, using the apparatus shown in FIG. It can be seen that the presence of internal moisture that could not be detected by the total HI-500 could be determined.

  In addition, the difference in humidity (+ 43%) between the initial state and the reduced pressure reduction state in this example was larger than the difference in humidity (+ 21%) in Example 2 on the surface of the concrete pavement plate 11. This is probably because the amount of tap water is reflected. In other words, in this embodiment, a larger amount of tap water flows than in the second embodiment, so that the amount of water stored in the concrete pavement board 11 is also greater in the present embodiment than in the second embodiment. The measured humidity difference is considered to reflect the amount of moisture in the interior. For this reason, it turns out that the moisture content inside the concrete pavement board 11 can be measured correctly by using the apparatus shown in FIG.

(Example 5)
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  JIS A-5371 concrete pavement board 11 (30 cm × 30 cm) was prepared, and this concrete pavement board 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 80% for one day. After that, the pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 80%.

  The internal space 1a of the pressure vessel 1 was depressurized by the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. The humidity in the internal space 1a in the decompressed state when the decompression was stopped was 60%.

  After the decompression was stopped, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gap of the concrete pavement plate 11 or the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. At this time, A.P.I. is (53.3-8.0) / 266 seconds = 0.17 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state was stabilized at 72%.

  From the above measurement results, the difference in humidity between the initial state and the reduced pressure reduction state was a low value of −8%, so it can be determined that the concrete pavement plate 11 is dry concrete containing almost no moisture inside.

  In addition, after drying for 60 hours at 80 ° C., the surface moisture of the concrete pavement board 11 left in a room at a temperature of 23 ° C. and a humidity of 80% for one day is measured with a high-frequency capacitance moisture meter HI-500 (Kett Scientific Research). Measured using a laboratory), the measured value of water content was 3.6%.

  From this result, the concrete pavement board 11 was judged to be the amount of water that can be applied in the coating floor as described in the coating floor handbook issued by the Coating Floor Industry Association.

(Example 6)
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  JIS A-5371 concrete pavement board 11 (30 cm × 30 cm) was prepared, and this concrete pavement board 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 80% for one day. Thereafter, 10 g of tap water was poured from the surface of the concrete pavement plate 11, and after 5 minutes, moisture on the surface of the concrete pavement plate 11 was wiped off with a waste cloth. After that, it was allowed to stand for another 4 hours, and it was confirmed that the moisture on the surface layer was scattered and the surface state of the concrete pavement plate 11 was visually the same as the state before flowing water.

  The moisture content on the surface of the concrete pavement plate 11 in this state was 3.6% when measured using a high-frequency capacitance moisture meter HI-500 (manufactured by Kett Science Laboratory).

  The pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 80%.

  The internal space 1a of the pressure vessel 1 was depressurized by the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. The humidity in the internal space 1a in the reduced pressure state when the pressure reduction was stopped was 64%.

  After the decompression was stopped, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gap of the concrete pavement plate 11 or the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. In this case, A.P.I. is (53.3-8.0) / 324 seconds = 0.14 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state increased to 88%.

  From the above measurement results, the humidity difference between the initial state and the reduced pressure reduction state was as high as + 8%. Therefore, compared to Example 5, the concrete pavement plate 11 of this example has moisture inside. It can be judged that it contains a lot.

  On the other hand, in view of the fact that the measured value of moisture with the high frequency capacitive moisture meter HI-500 was the same as that of Example 5, using the apparatus shown in FIG. It can be seen that the presence of internal moisture that could not be detected by the total HI-500 could be determined.

  In addition, the humidity difference (+ 8%) between the initial state and the reduced pressure reduction state in this embodiment is smaller than the humidity difference (+ 21%) in Embodiment 2 because the initial state is a high humidity state. In such a case, even if there is moisture in the concrete, the moisture in the air is originally high, so even if the pressure is reduced, most of the moisture contained in the concrete does not come out into the internal space 11a. It is thought that.

(Example 7)
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  A concrete pavement plate 11 (30 cm × 30 cm) having a water to cement ratio (water / cement (= W / C)) of 45% was left and cured for one month with the surface open. The concrete pavement plate 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 50% for 1 day.

  The moisture content on the surface of the concrete pavement board 11 in this state was 2.8% when measured using a high frequency capacitance moisture meter HI-500 (manufactured by Kett Science Laboratory).

  The pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 50%.

  The internal space 1a of the pressure vessel 1 was depressurized by the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. When the decompression was stopped, the humidity in the internal space 1a in the decompressed state was 25%.

  After the decompression was stopped, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gap of the concrete pavement plate 11 or the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. In this case, A.P.I. is (53.3-8.0) / 503 seconds = 0.09 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state was stabilized at 30%.

  From the above measurement results, the difference in humidity between the initial state and the reduced pressure reduction state was as low as -20%. Therefore, it can be determined that the concrete pavement plate 11 is dry concrete containing almost no moisture inside.

  Moreover, since the moisture content measured with the high frequency capacitance type moisture meter HI-500 is 2.8%, the concrete pavement board 11 can be used for the coating floor construction described in the coating floor handbook issued by the Coating Floor Industry Association. The amount was judged.

(Example 8)
Referring to FIG. 1, a vacuum pump 2 and a temperature / humidity sensor 3 (Anritsu Keiki Co., Ltd.) are provided in each of the mouths 1c ₁ , 1c ₂ , and 1c ₃ of a glass-made 20-cm diameter three-necked separable flask as the pressure vessel 1. A pressure-resistant temperature / humidity sensor TA502RWS) and a digital pressure gauge 4 were installed. Note that the vacuum pump 2 was connected to the mouth 1c _{1 of the} pressure vessel using a pressure hose 7, and the logger 6 (logger AM8000K) was connected to the temperature / humidity sensor 3. By using the temperature / humidity sensor 3 and the logger 6, the temperature and humidity can be detected every second.

  A concrete pavement plate 11 (30 cm × 30 cm) having a ratio of water to cement (water / cement (= W / C)) of 65% was left and cured for one month with the surface open. The concrete pavement plate 11 was dried at 80 ° C. for 60 hours and then left in a room at a temperature of 23 ° C. and a humidity of 50% for 1 day.

  The moisture content on the surface of the concrete pavement plate 11 in this state was 1.9% when measured using a high frequency capacitance moisture meter HI-500 (manufactured by Kett Science Laboratory).

  The pressure vessel 1 was brought into close contact with the concrete pavement plate 11 as a seal member 5 through silicon rubber packing. At this time, when the temperature and humidity in the internal space 1a of the pressure vessel 1 were measured, the temperature was 23 ° C. and the humidity was 50%.

  The internal space 1a of the pressure vessel 1 was depressurized by the vacuum pump 2, and the depressurization was stopped when the pressure in the internal space 1a reached 8.0 kPa. The humidity in the internal space 1a in the decompressed state when the decompression was stopped was 26%.

  After stopping the pressure reduction, the pressure vessel 1 was left for a predetermined time in a state of being in close contact with the concrete pavement plate 11. At this time, the pressure in the internal space 1a of the pressure-resistant vessel 1 gradually increased due to the inflow of air by natural intake from the gaps of the concrete pavement plate 11 and the like. The air permeability index A.P.I. (kPa / sec.) Was evaluated by measuring the time until the pressure in the internal space 1a reached 53.3 kPa. In this case, A.P.I. is (53.3-8.0) / 46 seconds = 1.09 kPa / sec. Met. Moreover, when the pressure in the internal space 1a of the pressure vessel 1 returned to 53.3 kPa, the humidity in the internal space 1a in the reduced pressure reduction state was stabilized at 39%.

  From the measurement results of the above A.P.I., it can be seen that the concrete pavement plate 11 of this example has more voids than the concrete pavement plate 11 prepared in Example 7 above. That is, the concrete pavement plate 11 of this example prepared under exactly the same curing conditions except that only W / C is different from the above Example 7 is the concrete pavement plate 11 of Example 7 in terms of voids and density in the concrete. It can be judged from the air permeability index API.

  When the moisture content is measured with a high-frequency capacitance moisture meter HI-500 (manufactured by Kett Scientific Laboratory), as shown in Examples 1, 3, 7 and 8, the measurement site due to the difference in the density of the concrete The index value of water content is greatly different depending on the contact area. From this, it can be seen that when this moisture meter is used, the measured moisture content varies greatly depending on the surface condition of the concrete pavement plate 11. Specifically, in Examples 1, 3, 7 and 8, the ratio of the maximum value to the minimum value of the moisture content (maximum value / minimum value) is 3.8 / 1.9 = 200%, and the variation becomes large. I understand that.

  On the other hand, in the measurement of the amount of water using the apparatus shown in FIG. 1, even if there is a difference in the density of the concrete as shown in Examples 1, 3, 7 and 8, variation in the measured value due to the difference in the density. Can be kept small. Specifically, the ratio (maximum value / minimum value) of the maximum value to the minimum value of the humidity in the reduced pressure reduction state in Examples 1, 3, 7, and 8 is as small as 39/30 = 130%. I understand that.

  In addition, in said Examples 1-8, although the case where the moisture content in the concrete pavement board 11 was evaluated from the humidity difference of an initial state and a reduced pressure reduction state was demonstrated, the humidity of a reduced pressure state and a reduced pressure reduction state The amount of water inside the concrete pavement plate 11 may be evaluated from the difference.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  INDUSTRIAL APPLICABILITY The present invention can be applied particularly advantageously to a concrete evaluation apparatus and a concrete evaluation method for simply and quickly measuring the moisture content inside concrete at a construction site.

It is sectional drawing which shows roughly the structure of the concrete evaluation apparatus in one embodiment of this invention. It is a flowchart which shows the concrete evaluation method in one embodiment of this invention.

Explanation of symbols

1 pressure vessel, 1a internal space, 1b opening, 1c ₁ , 1c ₂ , 1c ₃ port, 2 pressure reducing member, 3 humidity measuring member, 4 pressure measuring member, 5 seal member, 6 logger, 7 pressure resistant hose, 8 rubber plug 10 Concrete evaluation equipment, 11 Concrete (paving board).

Claims (5)

A pressure vessel having an internal space leading to the outside;
A decompression member for decompressing the internal space of the pressure vessel;
A humidity measuring member for measuring the humidity of the internal space of the pressure vessel,
The humidity measuring member includes the humidity of the internal space in any of an initial state before the internal space is depressurized by the decompression member and a decompressed depressurized state, and the internal space by natural intake from the depressurized state. A concrete evaluation apparatus configured to be able to measure the humidity of the internal space in a reduced pressure reduction state where the pressure reduction degree of the space is reduced.   The concrete evaluation apparatus according to claim 1, further comprising a pressure measuring member for measuring a pressure in the internal space of the pressure vessel.   The concrete evaluation according to claim 1, further comprising a sealing member for closely attaching the pressure resistant container to a surface of the concrete so that the internal space is sealed with concrete at an opening that leads to the outside of the pressure resistant container. apparatus. A step of bringing the pressure vessel into close contact with the surface of the concrete so as to seal the opening of the internal space of the pressure vessel with concrete; and
Reducing the internal space from the initial state to a reduced pressure state;
Lowering the degree of decompression of the internal space by natural intake from the decompressed state to bring the internal space into a reduced degree of decompression;
Evaluating the moisture content in the concrete based on a humidity difference between the humidity of the internal space in any of the initial state and the reduced pressure state and the humidity of the internal space in the reduced pressure reduction state A method for evaluating concrete.   A step of evaluating the air permeability of the concrete by measuring the time from the reduced pressure state to the reduced pressure reduction state and the pressure of the internal space in each of the reduced pressure state and the reduced pressure reduction state. The method for evaluating concrete according to claim 4 provided.

Images