JP2011180014A - Measuring instrument for unit water quantity of ready-mixed concrete - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring instrument for unit water quantity of ready-mixed concrete which is compact and which does not become a large-scaled system, and capable of easily measuring the unit water quantity of ready-mixed concrete on a casting site, at low cost. <P>SOLUTION: The unit water quantity measuring instrument 1 of ready-mixed concrete includes an air meter 2 for measuring the amount of air in a sample collected from ready-mixed concrete and a computer 3, in which a computer program for an estimation equation of unit water quantity is stored and computes the unit water quantity in the ready-mixed concrete by the computer 3, on the basis of the measured amount of air in the sample; the independently measured mass of the sample; and the mixture of the ready-mixed concrete. An iPod Touch 14 is used as the computer 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a unit water amount measuring device in fresh concrete that measures the unit water amount in fresh concrete by an air meter method.

The strength of concrete is determined by the weight ratio of water and cement, etc. If there is a lot of water, the strength of the concrete will decrease and cracking will easily occur. Therefore, while sufficiently manage the kneading water when fresh concrete production, the timing of the punching設前including during unloading by hitting設現field concrete unit water in fresh concrete (water per fresh concrete 1 m ³⁾ It is required to measure and measure to ensure that the concrete is placed.

  By the way, in recent years, phenomena such as peeling due to embrittlement of concrete occurred in tunnels, etc., and the Ministry of Land, Infrastructure, Transport and Tourism indicated an allowable value for unit water volume in ready-mixed concrete as a durability guideline, and cast ready-mixed concrete. It was obliged to measure the unit water volume when installing.

  The method for measuring the amount of unit water in ready-mixed concrete includes high-frequency heat drying method, general heat drying method, reagent concentration difference method using alcohol, etc., moisture measurement method such as capacitance measurement method and RI moisture meter, infrared moisture Many methods are known, such as a method using a meter, and an air meter method.

  Above all, the air meter method for obtaining the unit water volume from the air volume and mass of ready-mixed concrete has a sample volume of 5 to 7 liters compared to other measurement methods, so that the test can be performed with a capacity that can ignore the sampling error of the sample. Since the test method can be carried out in the same manner as the conventional air amount test, the applicability to the field is high due to the simplicity and quickness of the measurement.

  Conventionally, as a unit water volume measuring device by the air meter method, an air volume measuring device (air meter) of ready-mixed concrete is installed on a mass (weight) measuring unit, and a pressure gauge and mass measuring unit attached to the air chamber of the air volume measuring device While configuring the measuring device body with a wireless transmission / reception function, install a central control unit, for example, in a ready-mixed concrete manufacturing plant away from the placement site, and wirelessly transmit the measured mass data and pressure data to the central control unit In addition, there has been proposed a system in which a unit water amount is calculated and displayed by a calculation display unit of a central control unit so that the unit water amount can be managed remotely (see, for example, Patent Document 1).

  According to the proposed unit water amount measuring apparatus, there is an advantage that the unit water amount can be known and centrally managed at a place away from the concrete placement site. However, in addition to the main body of the measuring device brought to the installation site, a centralized control facility must be installed at a location away from it, and measurement data etc. must be transmitted and received wirelessly. It is necessary to provide the data processing / management means, and the whole unit water volume measuring device becomes a large-scale system. Moreover, since the air quantity measuring device is integrated on the mass measuring unit, the measuring device main body is enlarged.

  For this reason, conventionally, there has been known a unit water amount measuring apparatus that can easily measure the unit water amount in the ready-mixed concrete at a setting site without becoming a small, large-scale system (for example, Patent Documents). 2).

  Here, in the invention described in Patent Document 2, the measured air amount and other measured values, and the blending of ready-mixed concrete (mixed concrete for short) (cement, water, fine aggregate, coarse aggregate used in ready-mixed concrete) As a computer for calculating the unit water amount from the amount of air and the amount of air), general PDA (Personal Digital Assistants) that is small and highly portable is used.

JP 2000-14602 A JP 2006-3121 A

However, conventional PDAs (Personal Digital Assistants) cannot be used continuously due to the change of the times and the suspension of communication services. In addition, conventional PDA (Personal
In Digital Assistants), there is a problem that it is relatively expensive in the current economic environment where cost reduction is advancing.

  Accordingly, the present invention provides a unit water amount measuring device in ready-mixed concrete that can measure a unit water amount in ready-mixed concrete easily at a setting site without being a small and large-scale system and at a low cost. For the purpose.

  1st invention of this application is equipped with the air meter which measures the air quantity in the sample extract | collected from the ready-mixed concrete, and the computer which stored the calculation program of the estimation formula of unit water quantity, About the measurement air quantity of the said sample, and about the said sample A device for measuring unit water content in fresh concrete, wherein the unit water content in the ready-mixed concrete is calculated by the calculator from the measured mass measured separately and the composition of the ready-mixed concrete, and the calculator is an ipod touch. It is characterized by.

  According to the first aspect of the present invention, an ipod touch can be used as a calculator for calculating the unit water amount in the ready-mixed concrete. In addition, since the iPod touch alone is widely distributed in the market, it can be obtained at a relatively low cost.

  A second invention of the present application is the first invention of the present application, wherein the computer has a wireless communication function capable of wireless communication with a communication terminal device, and a calculation result of a unit water amount in the ready-mixed concrete obtained by the computer is obtained by wireless communication. It is transmitted to another communication terminal device.

  According to the second invention of the present application, since the calculation result of the unit water amount in the ready-mixed concrete obtained by the computer is transmitted to another communication terminal device by wireless communication, the data transmission / reception cable itself becomes unnecessary. Unit water quantity measurement in ready-mixed concrete becomes easy at the site where the measuring device is brought. In addition, it is possible to reliably and accurately measure the unit water amount in the ready-mixed concrete without causing a failure due to the breakage of the data transmission / reception cable.

  According to the present invention, the unit water amount in the ready-mixed concrete can be easily measured at a setting site at a low cost without becoming a small and large system.

It is a general view which shows the Example of the unit water amount measuring apparatus in the ready-mixed concrete of this invention. It is explanatory drawing for demonstrating the principle of unit water quantity estimation by the air meter method. It is explanatory drawing of the ipod touch (computer) which comprises the unit water amount measuring apparatus in the ready-mixed concrete of this invention.

  The unit water amount measuring apparatus in the ready-mixed concrete concerning 1st Embodiment of this invention is demonstrated with reference to drawings.

  FIG. 1 is an overall view showing an embodiment of a unit water amount measuring device in ready-mixed concrete of the present invention. The unit water volume measuring device 1 includes an air meter 2 that measures the amount of air in the ready-mixed concrete, its measured air volume and other measured values, and a mix of ready-mixed concrete (mixed concrete for short) (cement used for ready-mixed concrete, water And an ipod touch (computer) 3 that calculates a unit water amount from the fine aggregate, the amount of coarse aggregate, and the amount of air).

  The air meter 2 includes a flanged cylindrical container 4 for filling a sample collected from ready-mixed concrete, and a lid 5 that covers the upper opening of the container 4 and seals the inside of the container. An air chamber 6 is formed on the top of the lid 5. The air chamber 6 is provided with an exhaust valve 7, a manual air pump 8, a pressure gauge 9, a pressure regulating valve 10, and an opening / closing operation valve 11 for communicating the air chamber 6 with the shallow conical bottom surface of the lid 5. Also, the lid 5 is not visible behind the air chamber 6 in the figure, but a water supply port with an opening / closing cock and a plurality of lids that are engaged with and fastened to the flange 4a of the container 4 when the lid is closed. The fastener 12 is provided.

The method for measuring the amount of air in ready-mixed concrete is JIS standard (JIS A
1128), in addition to the air meter 2, a stick, a graduated cylinder, a syringe, a straight edge, and a calibration pipe are used to operate in a certain procedure. In order to measure the unit water content in ready-mixed concrete, it is necessary to measure the mass of the sample, and a mass meter (balance) is prepared separately. The mass meter only needs to have a weight of 25 kg or more and a minimum scale of 5 g or less.

  As shown in FIGS. 1 and 3, the computer 3 is not limited to a terminal device that can be connected to the Internet, and has a wireless LAN function (for example, Wi-Fi) even without an Internet connection function. I just need it. Specifically, the computer 3 uses an ipod touch (ipod touch, manufactured by Apple Inc.) 14 having a built-in flash memory. By applying the ipod touch 14 as the computer 3, it is small in size and highly portable and economical. In addition, a data communication function and a communication function with another communication terminal device (for example, a personal computer) 16 adopt a wireless communication system. In addition, it is not restricted to the ipod touch 14 with a wireless LAN function, If the ipod touch 14 is not equipped with the wireless LAN function, the ipod touch 14 and other communication terminals may be used using a wire such as a data transmission / reception cable. You may connect with the apparatus 16 and you may transmit the measurement result of the unit water quantity in ready-mixed concrete to the other communication terminal device 16. However, by constructing a wireless environment and performing wireless communication, the data transmission / reception cable itself becomes unnecessary, and therefore, it becomes easy to work at the site where the unit water amount measuring device 1 is brought in. In addition, there is no failure due to damage to the data transmission / reception cable.

  The ipod touch 14 is characterized in that the physical buttons are reduced to one and most operations are performed by touching the screen 15. Also, unlike a general touch panel, by using a touch panel called “multi-touch”, it is possible not only to touch the screen 15 but also to recognize how fast it is touching and display the displayed items. Conventionally, such as controlling the speed of scrolling, and intuitively enlarging / reducing photos displayed on the screen 15 of the iPod touch 14 by pushing and spreading or pinching the screen 15 with a plurality of fingers. Advanced operations not available on the touch panel are possible.

  As shown in FIG. 3, the ipod touch 14 mainly has a CPU 14A and a ROM 14B. The ROM 14B stores a calculation program for calculating the unit water amount in the ready-mixed concrete, in which the principle of unit water amount estimation by the air meter method shown below and a predetermined estimation formula are adopted. Based on the calculation program stored in the ROM 14B, the CPU 14A calculates the unit water amount in the ready-mixed concrete (details will be described later).

Here, the principle of unit water amount estimation by the air meter method will be described.
FIG. 2 schematically shows material distribution in fresh concrete packed in an air meter. 2B is a composition with a large amount of water compared to FIG. 2A, and the density of water is considerably smaller than the density of aggregate and cement. Therefore, FIG. ) The concrete mass is small. As the amount of water in the concrete changes, the unit volume mass of the concrete also changes. In addition, since the unit volume mass of concrete also varies depending on the amount of air, the amount of air in the concrete is accurately measured in addition to the volume and mass, and the unit volume mass excluding air (the unit volume obtained in the test) Mass γ2) is obtained, and this value is compared with the unit volume mass (unit volume mass γ1 on the formulation table) excluding air obtained from the formulation table, thereby estimating the unit water amount. In addition, since the aggregate occupies most of the concrete mass, if the density of the aggregate is not accurately grasped, the estimation accuracy of the unit water amount is lowered. An air meter is a device that accurately measures the amount of air, and since the volume of the container is constant, the unit water amount can be estimated simply by measuring the mass of the sample when measuring the amount of air.

  In the measuring apparatus of the present invention, the air meter method is adopted for measuring the unit water amount. The air meter method measures the air amount of the ready-mixed concrete with the air meter, and the measured air amount and the mass of the ready-mixed concrete measured separately. The unit water volume is calculated from the above. Specifically, the unit water mass is estimated by comparing the “unit volume mass γ1 on the blending table” with the “unit volume mass γ2 obtained in the test” of the ready-mixed concrete. The estimation formula derived by the civil engineering research institute (hereinafter referred to as the DOken formula estimation formula) is used. The computer 3 is preinstalled with a calculation program for the DOken type estimation formula and other necessary programs.

The unit volume mass and the DOken formula estimation formula are as follows.
Unit volume mass γ1, γ2
γ1 = Mc / {1− (Air + α) × 0.01} (1)
γ1: Unit volume mass excluding air volume on the recipe (kg / m ³ )
Mc: Mass per 1 m ³ of concrete on the recipe (kg / m ³ )
Air: Air volume (%) on the recipe
α: Volume reduction due to water infiltration into cement particles (%)
The unit cement amount is 0.01% per 100 kg / m ³ .

γ2 = M2 / {V2−V3 × Air2 × 0.01} (2)
γ2: Unit volume mass (kg / m ³ ) excluding the amount of air obtained in the test
M2: Mass of the sample (g)
V2: Sample volume (liter)
In the water injection method, V2 = total container volume-water injection amount, in the non-water injection method, V2 = V3
V3: Volume of the container in which the sample is packed Air2: Amount of air in the sample (%)
Air2 = Measurement air volume-Aggregate correction factor
Γ2 of the concrete kneaded with the normal mixing formula of the unit water quantity estimation formula should show the same value as γ1, but the actual concrete has the W 'hydration on the concrete as shown in the formula (1) If so, the actual unit volume mass γ2 can be expressed as equation (3) by rewriting equation (1).

γ2 = (Mc + W ′) / {1− (Air + α) × 0.01 + W ′ × 0.001} (3)
W ': Unit water error (kg / m ³ )
When W ′ is obtained from Equation (3),
W ′ = {γ2 (1− (Air + α) × 0.01) −Mc} / (1−γ2 × 0.001) (4)
It becomes. Therefore, the estimated unit water amount W can be obtained by Expression (5).

W = W1 + W ′ = W1 + {γ2 (1− (Air + α) × 0.01) −Mc} / (1−γ2 × 0.001) (5)
W: Estimated unit water volume (kg / m ³ )
W1: Unit water volume on the recipe (kg / m ³ )

  Next, a method for measuring the unit water amount in the ready-mixed concrete by the measuring apparatus of the present invention will be described. In addition, although the measurement of the air quantity was made into the non-poured water method, also when measuring by the poured water method, unit water quantity can be measured by operation according to the anhydrous method.

First, the volume of the container 4 of the air meter 2, the total volume of the container 4 including the lid 5, and the mass of the air meter 2 are input in advance on the touch panel screen of the ipod touch 14 (computer 3). In addition, each mass (kg) and air amount (%) of water, cement, fine aggregate and coarse aggregate are input. Next, JIS for samples collected from ready-mixed concrete
The amount of air is measured according to A 1128 (described later), and the mass of the sample is also measured.

In the measurement of the air amount according to JIS A 1128, first, about 20 kg of a sample is taken from the ready-mixed concrete, and the sample is packed into the container 4 of the air meter 2 with a stick, and the surface of the packed ready-mixed concrete is straight edged. After smoothing, tighten the lid 5. The mass of the container packed with the sample is measured together with the lid (M _A ), and the mass (M _B ) of the sample is determined from M _B = M _O −M _A (M _O : air meter mass). Next, compressed air is introduced into the air chamber 6 of the air meter 2 by the manual air pump 8 and kept at a high pressure state, and the pressure in the air chamber 6 at that time is measured by the pressure gauge 9. Next, the on-off valve 11 is opened to allow the air chamber 6 to communicate with the lower surface of the lid 2 so that the compressed air in the air chamber 6 acts on the ready concrete in the container 4. As a result, when the pressure of the air in the air chamber 6 and the container 4 is balanced, and the equilibrium pressure is measured by the pressure gauge 9, the air in the concrete is reduced as the equilibrium pressure from the initial pressure (reduction = initial pressure−equilibrium pressure). The amount (%) is measured. The amount of air is measured in units of 0.1%.

  When the air amount and mass of the sample are measured, the measured air amount and measured mass of the sample are input to the screen of the ipod touch 14. Based on the calculation program stored in the ROM 14B of the ipod touch 14, the CPU 14A executes the calculation of the DOken formula estimation formula and obtains the calculation result. The unit volume mass and the sample of the sample are displayed on the screen of the ipod touch 14. The estimated unit water amount is displayed together with the estimated value of the error of the unit volume mass and the unit water amount, and the measured value of the unit water amount is obtained.

  As described above, according to the unit water amount measuring apparatus 1 of the present invention, the unit water amount in the ready-mixed concrete is calculated from the amount of air in the sample measured with the air meter, the mass of the sample measured separately, and the blend of concrete. The calculation uses the Ipod Touch 14 with a built-in formula for estimating the unit water amount, so the device is small and does not become a large-scale system. Measure and display measurement results.

  In particular, the ipod touch 14 can be used as the calculator 3 of the unit water amount in the ready-mixed concrete. Further, since the iPod touch 14 alone is widely distributed in the market, it can be obtained at a relatively low cost.

  Furthermore, if the wireless LAN (wireless communication) of the ipod touch 14 is used, the measured value of the unit water amount in the ready-mixed concrete can be easily transmitted to the communication terminal device 16 as data. As a result, a data transmission / reception cable or the like becomes unnecessary, and the cable does not interfere with the work even if the unit water amount measuring device 1 is brought to the site. In this way, by constructing a wireless communication environment and performing wireless communication, the data transmission / reception cable itself becomes unnecessary, and therefore, it becomes easy to work at the site where the unit water amount measuring device 1 is brought in. In addition, it is possible to reliably and accurately measure the unit water amount in the ready-mixed concrete without causing a failure due to the breakage of the data transmission / reception cable.

1 Unit Water Quantity Measuring Device 2 Air Meter 3 Computer 4 Container 5 Lid 6 Air Chamber 9 Pressure Gauge 14 Ipod Touch (Computer)

Claims (2)

An air meter that measures the amount of air in a sample collected from ready-mixed concrete, and a computer that stores a calculation program for a unit water amount estimation formula, the measured air amount of the sample, and a measured mass separately measured for the sample And a unit water amount measuring device in the ready-mixed concrete for calculating a unit water amount in the ready-made concrete by the calculator from the blend of the ready-mixed concrete,
The said computer is an ipod touch, The unit water amount measuring apparatus in the ready-mixed concrete characterized by the above-mentioned. The computer includes a wireless communication function capable of wireless communication with a communication terminal device,
The apparatus for measuring unit water content in ready-mixed concrete according to claim 1, wherein the calculation result of the unit water content in the ready-mixed concrete obtained by the computer is transmitted to the communication terminal device by wireless communication.

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