JP4725908B2 - Water meter for uncured kneaded material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a unit water meter for measuring moisture contained in fresh concrete, that is, uncured ready-mixed concrete.
[0002]
[Prior art]
Recently, embrittlement of concrete in highways and tunnels has been regarded as a problem, and the Ministry of Land, Infrastructure, Transport and Tourism has endured the measurement of water content in fresh concrete (fresh concrete: ready-mixed concrete), that is, unit water volume, to maintain the original strength of concrete. Permissible value of unit water is shown as a sex guideline, and unit water measurement is obligatory.
[0003]
The strength and durability of concrete are not only largely influenced by the water-cement ratio when mixing concrete, that is, the mixing ratio of water and cement, but also the air volume. There is also a need for a quick weighing method. The unit amount of water is the amount of water added at the time of production of raw kon, plus the surface water already attached to the aggregate, and the amount of this surface water varies significantly depending on the conditions and cannot be determined uniformly.
[0004]
In general, as a method for measuring the amount of water in the concrete that has been kneaded, a heat drying method, a capacitance method, a unit volume mass method (air pressure method), or the like is used.
[0005]
There are various methods such as a drying oven method, a vacuum drying oven method, a microwave oven method, etc., but the heating drying method is the same in all the heating drying methods in that the sample is heated only by a different drying heat source. Therefore, there is absolutely no difference between the water vapor generated by drying.
[0006]
The capacitance method uses the fact that the capacitance specific to the aggregate varies depending on the amount of water, and determines the blending amount and the amount of adhering water based on the value of the capacitance.
[0007]
[Problems to be solved by the invention]
However, the conventional unit volume mass method (air pressure method) has a drawback that it is not possible to easily measure the moisture content and the amount of air in the raw kon simultaneously. In addition, there is no means to remove water when it enters the air chamber attached to the sample container. Therefore, if water leaks and accumulates, it will affect the subsequent measurement results, impairing reliability, and high accuracy cannot be obtained. There was a drawback to say.
[0008]
In addition, since all water management has been performed artificially with conventional water meters, it has not been possible to carry out complex numerical management by exchanging data, such as the complicated allowance of comprehensive management of ready-mixed concrete.
[0009]
[Means for Solving the Problems]
In the present invention, the water draining means installed at the bottom of the air chamber at the top of the unit water meter (air pressure method) and the various data obtained by the unit water meter are all numerically controlled by a computer for diversity. It will be designed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
【Example】
The present invention relates to an improvement of a water meter for measuring the water-cement ratio of fresh concrete, the most important aspect of which is to provide a non-return check (3) valve in the lower part of the air chamber. This is a configuration that maintains the accuracy of the air volume (volume) in the air chamber, which is a reference when measuring the air volume, and is capable of achieving diversity by numerically managing the measurement data.
[0011]
Examples will be described in detail.
FIG. 1 is a plan view of the apparatus of the present invention shown in FIG. 2, and is composed of a sample container 1 for containing fresh concrete and a container lid 2 which is fixed on the upper surface of the container 1 in a watertight manner. In addition, as is apparent from FIGS. 1 to 4, an air chamber 3 communicating with the inside of the sample container via an operating valve is airtightly fixed on one half of the upper surface of the container lid 2.
[0012]
As shown in FIG. 5, a drain valve 4 is appropriately attached to the bottom of the air chamber 3 by screwing or the like, and water leaked into the air chamber 3 from the valve 7 or the like during operation of the operating valve 7. The ball valve 6 is pushed and removed by the central operating rod 5 by rotating the knob 4 'at the outer end so as to be easily removed.
[0013]
Also, in the air chamber 3, appropriate means such as a manual pump or a portable air cylinder (bicycle air cylinder) can be easily set on the top surface of the air chamber, and the air injection provided with a function of non-return action. An inlet 9 is provided, and an operation lever 8 of an operating valve 7 for opening and closing a vent hole formed in the container lid 2 is installed to cut off the air chamber and the inside of the container.
[0014]
On the right side of the container lid 2 (see FIGS. 1 and 2), a water inlet 10 with a stop cock is fixed through the container 2, and on the other side on the left side, the drain with a stop cock is inserted through the container lid. ) A mouth 11 is provided.
[0015]
In addition, an arithmetic device 13 for processing the pressure data in the air chamber detected by the pressure sensor 12 is provided adjacent to the air chamber 3, and the pressure data is sent from the pressure measurement sending unit 13 a of the arithmetic device 13 for centralized control. Wireless transmission to the receiving unit of the unit 16 is performed. A power source 14 such as a battery or a battery for operating the arithmetic unit 13 is built in the lower part thereof.
[0016]
Reference numeral 15 denotes a portable high-precision electronic scale that can be easily carried to any location, and has a built-in weight measurement sending unit 15a (FIG. 6) for centralized control of measurement results. The data is transmitted to the calculation display unit 16.
[0017]
The measurement method using a unit water meter will be described below. Here, the calibration of the container and the meter has already been performed, and the electronic balance 15 filled the weight of the sample container (air measurement device) with water. The weight of the sample container is measured, and the volume of the container is calculated by subtracting the former from the latter (the calculation display unit).
[0018]
Next, a concrete sample of a predetermined amount (about 8th part of the container capacity) is placed in a container according to JIS regulations, and the total weight is measured after filling the upper surface with water. The water is injected from the water injection port 10 into the space 2 'between the water surface in the container and the container lid 2, and the water is poured out from the drain port 11 to expel the internal air. The water inlet 10 and the drain outlet 11 are completely closed.
[0019]
Usually, the air chamber 3 is closed by the drainage valve 4 and the air inlet 9 by its own non-return action, and in this state, compressed air is injected from the inlet 9 by the manual pump or a simple air cylinder. Then, the inside is maintained at a predetermined pressure by a relief valve 9 ′ provided on the top surface in the air chamber 3.
[0020]
By rotating the knob 4 'of the drain valve 4, the ball valve 6 is pushed open by the valve rod 5, and water leaked from the portion of the operating valve 7 into the air chamber 3 at the time of water injection is instantaneously generated by air pressure. Eliminate outside. At this time, the pressure in the air chamber 3 slightly drops momentarily, but the air corresponding to the pressure drop is immediately supplied from the air inlet 9 and the relief valve (exhaust valve) 9 'operates so as not to become overpressure. Thus, the pressure is automatically adjusted so as to always maintain a constant air pressure P (100 kps).
[0021]
Accordingly, the volume in the air chamber (a preset known volume) can be accurately maintained. In this state, the air inlet 9 is closed, the lever 8 is pushed, the operating valve 7 is pulled up and opened, and the air chamber 3 is opened. Is instantaneously applied to the water surface in the sample container 1.
[0022]
When the compressed air in the air chamber acts on the water surface in the container as described above, the pressure indication value decreases according to the amount of air contained in the sample. Therefore, the pressure indication value at this time is the apparent air amount A ₁ ( %), And by subtracting the correction coefficient G of the aggregate of the material used from this value, the air quantity A (%) of the concrete is calculated.
[0023]
That is, by taking the pressure balance between the air chamber and the container, the amount of air in the concrete is calculated from the relationship between the amount of reduced pressure and the amount of air (%) obtained in advance and stored in the computer.
[0024]
In this way, the water is calculated by subtracting the unit volume weight of the concrete (such as aggregate), the specified amount of cement (known), and the amount of air from the total weight, and the water cement ratio W / C is calculated from the amount of water and the amount of cement. can get. All input processing calculations such as correction values and constants are processed according to a process preset by a computer, and the result is derived.
[0025]
Centralized control is possible by numerically managing all measurement data, and diversity can be achieved by wireless transmission between units.
[0026]
【The invention's effect】
In the present invention, the water staying at the bottom of the air chamber 3 can be instantaneously removed by operating the drain valve 4, so that there is no volume fluctuation in the air chamber 3 and high measurement accuracy can be maintained.
[0027]
Further, since the drain valve 4 is installed at the lowest position in the bottom of the air chamber 3, all the water staying at the bottom of the air chamber 3 can be removed at once.
[Brief description of the drawings]
1 is a plan view of the apparatus. FIG. 2 is a front view of the same. FIG. 3 is a left side view of the same. FIG. 4 is an enlarged cross-sectional view of an essential part of FIG. FIG. 6 is a unit diagram of the present invention.
DESCRIPTION OF SYMBOLS 1 Sample container 2 Container lid 3 Air chamber 4 Drain valve 9 'Relief valve 13 Arithmetic device 15 Electronic scale 16 Calculation display part

Claims (1)

  In an apparatus having an air chamber communicated with a sample container via an operating valve, a water drainage valve is provided at the lowest position of the bottom surface portion constituting the air chamber, and the water amount of the uncured kneaded material Total

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