Method for calculating and estimating the amount of condensation

Abstract

To provide a method for calculating an allowable amount of dew condensation inside the concrete.SOLUTION: A method for calculating the amount of dew condensation according to the present invention executes a measurement step of measuring the amount of dew condensation water generated on the surface of an object in a state where the object made of concrete is placed under test conditions with set temperature and humidity; a calculation step of calculating a theoretical amount of dew condensation under the test conditions, based on the temperature and humidity under the test conditions; and the calculation step of calculating the difference between the measured amount of dew condensation water and the theoretical amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for calculating the amount of condensation, and more particularly to a method for calculating the amount of condensation on an object made of concrete. The present invention also relates to a method for estimating the amount of condensation, and more particularly to a method for estimating the amount of condensation on a structure made of concrete. [Background technology]

[0002] The occurrence of condensation inside a building can affect the environment inside the building and materials stored inside the building. Therefore, it is common to predict whether or not condensation will occur inside the building, as well as the amount of condensation that will occur, and then take measures to prevent condensation depending on the prediction results (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-24367 Summary of the Invention [Problem to be solved by the invention]

[0004] When condensation occurs on the surface of a concrete structure, such as a concrete floor or wall in a building, the condensed water first forms inside the structure. Therefore, even in an environment where condensation is possible, the condensed water does not appear on the surface of the structure while condensation is occurring inside the structure, and condensation occurs on the surface of the structure when the amount of condensation inside the structure exceeds a predetermined amount (tolerance).

[0005] When taking measures against condensation in buildings, if the condensation characteristics of concrete mentioned above can be taken into consideration, more appropriate and rational measures can be considered. To do this, it is necessary to accurately understand the amount of condensation that occurs within the concrete, more specifically, the amount of condensation that can be tolerated within the concrete. Furthermore, it is necessary to use the results to estimate the amount of condensation inside concrete structures within buildings.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for calculating the allowable amount of condensation inside concrete. Another object of the present invention is to provide a method for estimating the amount of condensation in a structure to be estimated, using the results of calculations regarding the allowable amount of condensation inside concrete. [Means for solving the problem]

[0007] The above problem is solved by the method for calculating the amount of condensation of the present invention by carrying out a measurement process in which an object made of concrete is placed under test conditions with set temperature and humidity, and the amount of condensation water that occurs on the surface of the object; a calculation process in which the theoretical value of the amount of condensation water that will occur under the test conditions is calculated based on the temperature and humidity under the test conditions; and a calculation process in which the difference between the measured amount of condensation water and the theoretical value is calculated. The above method makes it possible to calculate the allowable amount of condensation inside an object made of concrete.

[0008] In the above-described method for calculating the amount of condensation, the measuring step may involve causing a water-absorbing material to absorb condensation water generated on the surface of the object, and measuring the amount of condensation water absorbed by the water-absorbing material. According to the above method, the amount of condensed water that forms on the surface of an object can be measured relatively easily.

[0009] In addition, the above-described method for calculating the amount of condensation may further include a cooling step of cooling the object until the surface temperature of the object reaches a predetermined temperature. In this case, the measuring step may be performed after the cooling step by placing the object under test conditions set so that the dew-point temperature becomes higher than the predetermined temperature. According to the above method, the state of the object can be adjusted to a state in which condensation is likely to occur, thereby allowing condensation to occur on the surface of the object, and as a result, the allowable amount of condensation inside the object can be appropriately calculated.

[0010] In addition, in the above-mentioned method for calculating the amount of condensation, a sampling step may be further carried out in which an object is sampled from a structure made of concrete that constitutes a building, and the measurement step may be carried out using the sampled object. According to the above method, for example, an object is collected from a structure installed in an actual building, and the allowable amount of condensation that can occur inside the object is calculated, thereby making it possible to determine the allowable amount of condensation for the structure.

[0011] In addition, in the above-mentioned method for calculating the amount of condensation, the calculation step may measure the temperature and humidity under the test conditions, as well as the surface temperature of the object, and calculate the theoretical value of the amount of condensation water that will occur on the surface of the object based on the measured temperature and humidity under the test conditions, as well as the surface temperature of the object. According to the above method, the theoretical value of the amount of condensation water that occurs on the surface of the object can be appropriately calculated based on the measurement results of the temperature and humidity under the test conditions and the surface temperature of the object.

[0012] In addition, in the above-mentioned method for calculating the amount of condensation, multiple types of objects with different surface finishes may be used, and the measurement process, calculation process, and calculation process may be carried out using each type of object, and the difference may be calculated for each type of object. According to the above method, the allowable amount of condensation inside an object is calculated for each type of object, and the allowable amount of condensation can be understood in relation to the finish state of the surface of the object.

[0013] Furthermore, the above-mentioned object can be achieved by the method for estimating the amount of condensation of the present invention by identifying a correspondence between the difference calculated by the above-mentioned method for calculating the amount of condensation and the water permeability rate measured in the following procedure A for a structure made of concrete under the same manufacturing conditions as the target object, and estimating the difference for the structure to be estimated based on the identified correspondence and the water permeability rate measured in procedure A for the structure to be estimated. Procedure A: The bottom of the water column is kept in contact with the surface of the object whose permeability rate is to be measured for a predetermined period of time, and the amount of water permeating through the object is determined from the change in the height of the water column during that period.The permeability rate through the object is then calculated based on the amount of water permeating and the time included in the period. According to the above method, the allowable amount of condensation that is calculated using the target object can be used to estimate the allowable amount of condensation that can occur inside the target structure. [Effects of the Invention]

[0014] According to the present invention, it is possible to calculate the allowable amount of condensation inside a concrete object. Furthermore, by utilizing the calculation result of the allowable amount of condensation, it is possible to estimate the amount of condensation occurring in the structure to be estimated (more specifically, the allowable amount of condensation inside the structure). [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 4 is a diagram showing a procedure for calculating the amount of condensation according to an embodiment of the present invention. [Figure 2] 10A and 10B are diagrams illustrating how condensation water generated on the surface of an object is absorbed by a water-absorbing material. [Figure 3] FIG. 1 is an explanatory diagram of a water permeability measurement test. [Figure 4] FIG. 10 is a diagram showing the correspondence relationship between the allowable amount of condensation and the water permeation rate. DETAILED DESCRIPTION OF THE INVENTION

[0016] <<About one embodiment of the present invention>> Hereinafter, one embodiment of the present invention (hereinafter referred to as the present embodiment) will be described with reference to the accompanying drawings. In the following description, warehouses and factories are used as examples of buildings, but the present invention can also be applied to other buildings such as houses.

[0017] In this specification, the term "amount of condensation" is synonymous with the amount of condensed water generated.

[0018] (Calculation of allowable amount of condensation) In this embodiment, the allowable amount of condensation (hereinafter referred to as the allowable condensation amount) inside an object is calculated. The object is an object (specimen) for which the allowable condensation amount is to be calculated, and is made of concrete. In this embodiment, for example, the object used is an object with a surface finish similar to that of the structures that make up a building, such as floors and walls in a building such as a warehouse or factory.

[0019] When calculating the allowable amount of condensation (specifically, when performing the measurement step described below), a target object may be prepared by creating a new concrete test specimen. Alternatively, the target object may be taken from a concrete structure such as a floor or wall that constitutes an actual building. Specifically, a portion of an existing structure may be cut out (or extracted) and used as the target object.

[0020] The allowable amount of condensation is the water absorption capacity of an object made of concrete, or in other words, the amount of condensation that can occur inside the object. In other words, if an object is placed in an environment where condensation can occur, and the amount of condensation is within the allowable amount, condensation will occur mainly inside the object, and the condensed water will not appear on the surface of the object. The amount of condensed water that occurs inside the object before it appears on the surface of the object corresponds to the allowable amount of condensation.

[0021] In this embodiment, the amount of condensation water generated inside the object until the condensation water appears on the surface of the object is divided by the surface area of ​​the object to obtain the amount of condensation water per unit area (for example, 1 m 2 ) converted to a value per unit (unit: g / m 2 ) is the allowable amount of condensation. However, it is not limited to this, and for example, the amount of condensation water that occurs inside the object until condensation water appears on the surface of the object is divided by the volume of the object to obtain the unit volume (for example, 1 m 3 The allowable amount of condensation may be calculated by converting the value per

[0022] Next, a method for calculating the allowable amount of condensation will be described with reference to Fig. 1. The method described below corresponds to the method for calculating the amount of condensation of the present invention, and each process (step) shown in Fig. 1 corresponds to an element constituting the method for calculating the amount of condensation of the present invention.

[0023] When calculating the allowable amount of condensation, first, an object is prepared. Specifically, an object is sampled from a concrete structure, such as a floor or wall, installed in an actual building (on-site) (S001). This step S001 corresponds to the sampling process. The structure on which the sampling process is performed has a predetermined surface finish; in other words, the surface condition of the structure is in a predetermined finished state. Therefore, the surface of the object sampled from the structure also has a predetermined finished state.

[0024] Next, the object collected in step S001 is cooled until its surface temperature reaches a predetermined temperature (S002). This step S002 corresponds to a cooling step. The set temperature in the cooling step (e.g., the target temperature of the object's surface) should be set to a suitable temperature from the viewpoint of successfully carrying out the next step S003, for example, about 10°C.

[0025] Next, the object cooled in step S002 (i.e., the object collected from the on-site structure) is placed under test conditions where the temperature and humidity are set to predetermined values, and the amount of condensation water that forms on the surface of the object is measured (S003). This step S003 corresponds to the measurement process. The test conditions (specifically, temperature and humidity) in the measurement process are set to, for example, 26°C and a humidity of 90% RH. Note that these values ​​are merely an example, and the temperature and humidity in the test conditions may be set to values ​​other than those mentioned above as long as the dew-point temperature is higher than the target temperature (predetermined temperature) of the object surface during the cooling process, creating conditions that make condensation more likely to occur.

[0026] The object is then exposed to the above test conditions and maintained for a certain period of time (for example, about 4 to 6 hours). During this period, condensation occurs around the surface of the object cooled in step S002. Condensation first occurs inside the object, and when the amount of condensation inside the object exceeds the allowable amount of condensation, condensed water occurs (becomes apparent) on the surface of the object. In step S003, the weight of the condensed water formed on the surface of the object is measured.

[0027] The method for measuring the weight of condensation water generated on the surface of an object is not particularly limited. As an example, as shown in Figure 2, the weight of condensation water generated on the surface of an object may be measured by absorbing the condensation water generated on the surface of the object into a water-absorbing material such as water-absorbing paper, and calculating the weight of the condensation water absorbed by the water-absorbing material from the weight of the water-absorbing material before and after water supply. The weight of condensed water is the amount per unit area (unit: g / m 2 ) can also be calculated.

[0028] Next, based on the temperature and humidity under the test conditions adopted in step S003, a theoretical value of the amount of condensation water generated under the test conditions is calculated (S004). This step S004 corresponds to a calculation step. The theoretical value of the amount of condensation water is the theoretical value of the amount of condensation water generated on the surface of the object, and more specifically, it is the amount of condensation when the allowable amount of condensation (i.e., water absorption capacity) of the object is not taken into consideration, that is, the amount of condensation when it is assumed that all of the condensation water is generated on the surface of the object. The theoretical value of the amount of condensation is the amount per unit area (unit: g / m 2 ) can also be calculated.

[0029] The theoretical value of the amount of condensation is calculated using a general calculation method. For example, in step S003 (measurement process), the temperature and humidity of the test conditions under which the object is placed, as well as the surface temperature of the object, are measured, and the theoretical value is calculated using the measurement results and the following equation (1). W=(fa-fs) / R Equation (1) In the above formula (1), W is the amount of condensation (unit: g / m 2 h), and R is the moisture conduction resistance (m 2 h·mmHg / g), fa is the water vapor pressure of the room air (unit: mmHg), and fs is the saturated water vapor pressure at the surface of the object (unit: mmHg). Here, for R, the general value (=0.08m 2 h·mmHg / g) is used. fa is calculated from the measured temperature and humidity of the test conditions using a known prediction formula such as Wagner's formula. fs is calculated from the measured surface temperature of the object using a known prediction formula such as Wagner's formula.

[0030] Note that step S004 (calculation step) may be performed before steps S002 and S003, or may be performed at the same time as step S002 or S003.

[0031] Next, the difference between the amount of condensation water measured in step S003 and the theoretical value calculated in step S004 is calculated (S005). This step S005 corresponds to a calculation step. Then, the allowable amount of condensation of the object is calculated from the calculated difference. Specifically, the calculated difference is calculated as the allowable amount of condensation. The allowable amount of condensation on the object is the amount per unit area (unit: g / m 2 ) can also be calculated.

[0032] By calculating the allowable amount of condensation for an object using the above-described procedure, it is possible to determine the allowable amount of condensation for a structure (specifically, a floor, a wall, etc.) created under the same conditions as the object. Once the allowable amount of condensation for a structure is known, it becomes possible to rationally consider measures to prevent condensation within a building that includes that structure.

[0033] Specifically, the amount of condensation that appears on the surface of a structure is reduced by the amount of condensation that the structure can tolerate, and by taking this into consideration, it is possible to design the capacity (dehumidification performance) of the dehumidification equipment to be installed inside the building with a lower capacity, which can result in reduced equipment costs. Also, depending on the environment (temperature, humidity, etc.) at the building construction site, it is possible that the amount of condensation expected to occur inside the structure will not exceed the allowable amount, in which case there is a possibility that measures to deal with condensation that occurs on the surface of the structure will not be necessary, resulting in further cost reductions.

[0034] (Example of calculation of allowable amount of condensation) Next, an example of calculating the allowable amount of condensation of an object using the above-described procedure will be described below. A test specimen of a specified size was taken from a concrete structure that had been finished with a rotary trowel, and this was used as the test object. After the surface of the test object was cooled to a specified temperature (approximately 10°C), it was placed under test conditions (approximately 90% RH at 26°C) set so that the dew point temperature was higher than the specified temperature. The test object was then exposed to the above test conditions for a certain period of time (approximately 4 to 6 hours), and the condensed water that appeared on the surface of the test object during that period was absorbed by a water-absorbing material and the amount of condensed water was measured. The amount of condensed water absorbed by the water-absorbing material (strictly speaking, the weight of condensed water per unit area) was approximately 5 g / m 2 It was. In addition, the temperature and humidity under the test conditions, as well as the surface temperature of the object, were measured, and the theoretical value of the amount of condensation water that would occur on the surface of the object was calculated based on these measurement results and the above formula (1). The theoretical value (strictly speaking, the theoretical value of the amount of condensation per unit area) was 490 g / m 2 It was. From the above values, calculate the difference between the measured amount of condensation water and the theoretical value, and from this calculated value, the allowable amount of condensation of the object is 485 g / m 2 (=490g / m 2 -5g / m 2 ) was obtained.

[0035] (Relationship between surface finish and allowable amount of condensation) The allowable amount of condensation on an object may vary depending on the surface condition of the object, more specifically, the finish of the surface of the structure from which the object was collected. In consideration of this, it is preferable to calculate the allowable amount of condensation using the above method separately for each finish.

[0036] That is, it is advisable to use multiple types of objects with different surface finishes, and perform the cooling, measuring, calculating, and deriving steps described above for each type of object to calculate the allowable amount of condensation (i.e., the difference between the measured amount of condensed water and the theoretical value of the amount of condensation) for each type of object. In this way, if the surface finish of the object is known, it is possible to derive the allowable amount of condensation for the object and the structure from which the object was taken from that finish.

[0037] The finish state is determined by the surface finishing method, etc. Examples of surface finishing include "mechanical rotary trowel finishing" using a horse-mounted trowel or a hand-pushed trowel, "fresno finishing" using a trowel about 1m long called a fresno, "trowel finishing" using a regular trowel, and other surface finishing methods such as "paint finishing".

[0038] (Estimating the amount of condensation) When the allowable amount of condensation is calculated by the above-described calculation method, the calculation result can be used to calculate the allowable amount of condensation for another concrete structure (hereinafter referred to as the structure to be estimated). Specifically, the water permeability rate is measured using the following procedure for a concrete structure created under the same conditions as the object for which the allowable condensation amount was calculated using the above-mentioned calculation method, for example, the structure from which the object was taken.

[0039] = Procedure for measuring water permeability = The bottom of the water column is brought into contact with the surface of the object whose velocity is to be measured (hereinafter simply referred to as the object). Specifically, as shown in Figure 3, a cylindrical container with an open end and a scale (for example, a container with an inner diameter of 30 mm) is placed upright on the surface of the object, and a predetermined amount of water is poured into the cylindrical container. The above state is then maintained for a preset period (e.g., 72 hours), and the amount of water permeating the object is determined from the change in the height of the water column during that period.Then, based on the determined amount of water permeating and the time included in the period (i.e., 72 hours), the water permeation rate through the object is calculated; specifically, the water permeation rate is calculated by dividing the amount of water permeating by the time included in the period.

[0040] Then, based on the allowable condensation amount calculated for a certain object and the water permeation rate measured for the structure from which the object was taken, the correspondence relationship between the allowable condensation amount and the water permeation rate is determined. Specifically, the calculation of the allowable condensation amount using the calculation method described above and the measurement of the water permeation rate according to the procedure described above are repeated for each of multiple structures with different finish states and for each of the objects taken from the multiple structures. In this way, a set (dataset) of the calculation results of the allowable condensation amount and the measurement results of the water permeation rate is obtained for each finish state.

[0041] The data sets acquired for each finish are plotted in a coordinate space as shown in Figure 4, and an approximation curve for the plot and an equation (approximation formula) that represents the approximation curve are identified. This approximation formula corresponds to the correspondence (strictly speaking, correlation) between the allowable amount of condensation and the water permeation rate. In the coordinate space of Figure 4, the horizontal axis represents the water permeation rate, and the vertical axis represents the allowable amount of condensation.

[0042] The water permeation rate of the structure to be estimated is then measured using the same procedure as described above. The allowable condensation amount for the designated structure is then estimated based on the water permeation rate measured for the structure to be estimated and the identified correspondence relationship. That is, the allowable condensation amount corresponding to the water permeation rate measured for the structure to be estimated is calculated using the approximation formula, and the calculated result can be used as the allowable condensation amount for the structure to be estimated.

[0043] This allows the allowable condensation amount of the target structure to be estimated easily, for example, in cases where it is difficult to collect an object from a concrete structure installed in an existing building, without having to calculate the allowable condensation amount using the above-mentioned calculation method. In other words, by measuring the water permeation rate, the allowable condensation amount of the target structure can be easily and appropriately estimated without having to perform the measurement process, calculation process, and calculation process on an object collected from the target structure.

[0044] In addition, for structures where a certain number of years have passed since the concrete was poured, the allowable amount of condensation may vary (become larger) from the original value. In such cases, it is preferable to collect a specimen from the structure and calculate the allowable amount of condensation using the calculation method described above.

[0045] <<Other embodiments>> Although one embodiment of the method for calculating the amount of condensation and the method for estimating the amount of condensation of the present invention has been described above, the above embodiment is merely an example for facilitating understanding of the present invention and does not limit the present invention. In other words, the present invention can be modified and improved without departing from the spirit and scope of the present invention. Furthermore, the present invention naturally includes equivalents thereof.

[0046] In the above embodiment, the allowable amount of condensation of an object is defined as the difference between the measured amount of condensation water generated on the surface of the object and the theoretical amount of condensation calculated based on the temperature and humidity of the test conditions. However, how this difference is defined can be determined appropriately depending on the intention of the person who uses this difference.

[0047] In the above embodiment, a correspondence (correlation) between the water permeation rate and the allowable amount of condensation is identified, and the allowable amount of condensation for the structure to be estimated is estimated based on the water permeation rate measured for the structure to be estimated and the identified correspondence, but this is not limited to this. Even if a parameter (measured value) other than the water permeation rate has a high correlation with the allowable amount of condensation, that parameter can be used instead of or in addition to the water permeation rate. In other words, a correspondence between a parameter other than the water permeation rate and the allowable amount of condensation can be identified, the parameter can be measured for the structure to be estimated, and the allowable amount of condensation for the structure to be estimated can be estimated based on the measurement results.

Claims

1. a measuring step of measuring the amount of condensation water generated on the surface of an object made of concrete while the object is placed under test conditions with set temperature and humidity; a calculation step of calculating a theoretical value of the amount of condensation water generated under the test conditions based on the temperature and humidity under the test conditions; a calculation step of calculating a difference between the measured amount of condensation water and the theoretical value; A method for calculating the amount of condensation to be carried out.

2. The method for calculating the amount of condensation according to claim 1 , wherein the measuring step comprises causing a water-absorbing material to absorb condensation water generated on the surface of the object, and measuring the amount of condensation water absorbed by the water-absorbing material.

3. A cooling step is further performed to cool the object until the surface temperature of the object reaches a predetermined temperature.

3. The method for calculating the amount of condensation according to claim 1, wherein the measuring step is performed after the cooling step by placing the object under the test conditions set so that the dew-point temperature is higher than the predetermined temperature.

4. A sampling step is further carried out to sample the object from a structure made of concrete that constitutes a building; The method for calculating the amount of condensation according to claim 1 , wherein the measuring step is performed using a sample of the object.

5. 5. A method for calculating the amount of condensation described in any one of claims 1 to 4, wherein in the calculation step, the temperature and humidity under the test conditions, as well as the surface temperature of the object, are measured, and the theoretical value of the amount of condensation water generated on the surface of the object is calculated based on the measured temperature and humidity under the test conditions, as well as the surface temperature of the object.

6. A method for calculating the amount of condensation described in any one of claims 1 to 5, using multiple types of objects with different surface finishes, performing the measurement process, the calculation process, and the calculation process using each type of object, and calculating the difference for each type of object.

7. A correspondence relationship is determined between the difference calculated by the method for calculating the amount of condensation according to any one of claims 1 to 6 and the water permeability rate measured by the following procedure A for a structure made of concrete under the same production conditions as the object, A method for estimating the amount of condensation, which estimates the difference for the structure to be estimated based on the identified correspondence and the water permeation rate measured for the structure to be estimated in step A. Procedure A: The bottom of a water column is kept in contact with the surface of the object whose permeability rate is to be measured for a predetermined period of time, the amount of water permeating into the object is determined from the change in the height of the water column during that period, and the permeability rate through the object is calculated based on the amount of water permeating and the time included in that period.

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