JPH08278268A - Water content meter using electrical detection circuit and concrete placement compartment detection device - Google Patents

Abstract

PURPOSE: To provide a detector of concrete before curing for automating and rationalizing the concrete placement construction of construction and engineering works. CONSTITUTION: In a unit detector, a pair of different kinds of metals are mounted to a concrete form as electrodes 11 through an insulator 03 and each electrode is connected to a signal converter 04 to constitute a concrete detection circuit. For automating concrete placement construction, data for indicating the progress condition of the filling operation of concrete which nearly correspond to the final process are required. Since the signal of the concrete detection circuit is an electrical signal and hence can be simultaneously used to control all processes, the signal is used, for example, to switch a transport pipeline, operate a pressure-feed pump, and control the operation of a batch plant, thus rationalizing and automating concrete placement operation. Then, the detector can be utilized as a monitoring meter of water content at the surface part of concrete after placement.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Construction, civil engineering, which uses concrete pumps to send concrete by pressure.

[0002]

2. Description of the Related Art In large-scale concrete pouring work in the fields of civil engineering and construction, after concrete is manufactured in a batch plant, it is quickly transported according to the construction plan and immediately around the corners of the formwork and around the reinforcing bars. You must drive it in all the way and then quickly and fully compact it. Care must be taken to ensure that the material separation of concrete is as small as possible from transport to the end of compaction. And, the time from kneading to finishing is less than 1.5 when the outside temperature exceeds 25 ° C and 2.0 when the outside temperature is below 25 ° C.
It is prescribed within the time limit and the standard method of JSCE.

Generally, the amount of concrete in one construction block, which is determined for construction reasons, depends on the work time until the completion of kneading, transporting, driving, compaction, and the capacity of construction equipment and the number of workers. It depends. As the quality of the concrete after hardening is affected, the ratio of kneaded aggregate, fine aggregate, cement and water, and admixtures used as needed, etc. is important, and the ratio varies depending on the intended use. Will be used. Therefore, in order to obtain concrete of the required quality, it is necessary to weigh the materials indicated in the method manual with the required accuracy and sufficiently mix these to make homogeneous concrete with little difference between batches.

As a concrete pouring work, there is a case where it is necessary to pour concrete having a different mixing ratio for each part in terms of structural mechanics even in an integrated structure.
In this case, the composition ratio of the above-mentioned kneading materials is changed and the composition is poured into the designed section to ensure proper performance of the concrete structure after completion.

Then, the concrete has the strength as designed,
In order to ensure durability, watertightness, etc., it is a necessary condition that the hydration reaction of the cement is sufficiently performed, but since the surface drying of concrete will progress early after pouring, Insufficient internal water content for the sum reaction. As a protective measure, it is necessary to keep the concrete surface in a wet state for a certain period of time. This is called curing and is an important quality control measure.

As a sensor for the purpose of batch identification of concrete having different material ratios and detection of the placement section, an electronic device having a sounding or emitting function described in Japanese Patent Publication No. 6-3071 is prepared. , It is placed with concrete, and the movement of the device and its position are used for batch identification of the level of concrete placement or the change of the kneading ratio by detecting the signal emitted by the electronic device, that is, sound and light. To be done.

[0007]

When considering the current state and trends of mechanization and automation of concrete construction, it is clear that the number of young people who want to build construction tends to decrease according to various data. Against this background, there is a shortage of labor and skilled labor in the present situation and in the future, and in order to respond to this, the development of construction methods aiming at labor saving and rationalization of concrete work. , Mechanization and automation are being promoted.

In order to apply the method of Japanese Patent Publication No. 6-3071 mentioned above as a method of detecting a concrete placing section, it is necessary to visually check and to follow the movement of the device by a means such as hearing sound. Therefore, it cannot be used for pouring concrete into the space closed by the formwork.

When using the above-mentioned means for detecting the concrete pouring section, a worker is specially arranged for visually recognizing the detector, and the transmission of the information depends on the person who visually recognizes the detector. The information prepared to inform the concrete pump operator of the situation at the concrete pouring site will be transmitted using the means prepared in. Therefore, since all the work is carried out through an artificial operation, a higher degree of automation of the work cannot be expected.

[0010]

When the operation of the concrete detection circuit applied to the present invention is explained as a model with reference to the attached FIG. 1, concrete before solidification can be regarded as a kind of aqueous solution. When the composed electrode (A) 11 and electrode (B) 12 are immersed in concrete 01, and both electrodes are connected by a conducting wire S as shown by a broken line, there is migration of ions between the two electrodes in concrete, that is, ion conduction. Due to this, a closed circuit is formed between both electrodes and a current I flows through the external conductor S. By detecting this current with a signal converter, it is possible to directly detect whether concrete before drying exists in the area. It becomes possible to do. This signal is used as an operation signal for changing the concrete pressure pump or transportation pipeline, and a control signal for the batch plant.

[0011] As a device for detecting a concrete pouring section when planning the pouring of concrete in a closed area as shown in FIG.
Electrode group consisting of combination of 2, 13 and 21, 22, 23
The electrode group, which is a combination of the above, is installed on the frame 02 via the insulator 03, and the concrete is viscous, so the supplied concrete is the concrete envelope N and the ground Since the fluid flows at an angle of repose P created by the level GL, by arranging the detection electrodes as shown in FIG. 3 in the formwork of the region shared by one supply point M and forming the detection circuit, concrete can be obtained. A pouring detection circuit that can check whether the area is filled with concrete or not while monitoring the flow of

[0012]

The concrete detection signal can be detected outside the concrete form, so that it can be integrated in the area completely closed by the form, for example, in the gap between the wall of the tunnel and the form as shown in FIG. Since concrete can be placed in the concrete and the continuity of concrete placing work can be easily secured, it becomes possible to construct a concrete structure with better performance.

Further, by using current for the detection signal, the extension of the signal line can be extended within a range of up to 20 km, and since it is an electric signal, it can be used simultaneously at any place in the work site. Therefore, comprehensive work management is possible, and it is possible to achieve high quality control of raw materials with little loss in time and personnel.

After the concrete pouring work is completed, the detection circuit is used as a device for determining the water content of the concrete surface layer because the degree of drying of the concrete surface, that is, the ion mobility affects the detection signal current value. Since it is possible to do so, it is possible to accurately grasp the condition setting for curing and the timing of dismantling the formwork.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. When the ground level in FIG. 3 is GL,
With the sensing electrodes 11 and 21 as a common electrode shell, electrodes 11 and 12, 13 and 14 have a combination of electrodes B, and electrodes 21 and 22 have a combination of electrodes 23 and 24, which are electrodes of two sets of sensing circuits. An example of the arrangement of the electrodes is shown in FIG.
Reference numeral 4 denotes a detection circuit corresponding to the installation position of the detection electrode by switching the switch (Sw). Therefore, the concrete is broken line N
When it is in the state shown by, the detection circuit consisting of the combination of each of the electrodes 21 and 22, 23 is activated to indicate the state of concrete, and the signal line from the electrode is guided to the operating point of the pump. Allow the operator to directly know the information on the setting site. On the other hand, when considering automation, the output of each electrode is the control signal of the on-off valve of the delivery line of the pressure pump,
It is used as a control signal for changing the transportation pipeline, a concrete supply amount to the pressure pump, or a batch plant control signal.

Although both electrodes constituting the detector described above are insulated from the mold, it is also possible to substitute the concrete mold as an electrode for either one of the electrodes.

[0017]

INDUSTRIAL APPLICABILITY As described above, the present invention utilizes the simultaneity of detection signals in a large-scale construction site in parallel operation of a plurality of pressure feed pumps or batches with different mixing ratios
Since it is possible to automatically operate the parallel operation of the plant based on the information of the concrete pouring site at any time, it is also possible to program a concrete pouring work of different properties based on the structural analysis of the structure, and a series of work It enables labor saving and automation, and automatic collection of work records, which enables higher quality control of construction work.

Due to the operating principle of the detector used in the present invention, it is not necessary to supply power to the electrodes of the detector from the outside. Therefore, since only one signal line is required per unit electrode, it is easy to handle and is suitable for field work where there are many accidents such as electric leakage and movement and laying changes are required as needed. Further, the detection electrode is economical because it can be used repeatedly.

After the concrete is poured, it becomes possible to function as a moisture meter for the concrete surface layer, so that it becomes easy to accurately control the curing work and the timing of dismantling the formwork.

[Brief description of drawings]

[Figure 1]: Concrete detection circuit diagram

[Fig.2]: Cross section of formwork and tunnel

[Fig. 3]: Front view of the mold and electrode arrangement diagram

[Explanation of symbols]

 01: Filled concrete 02: Constructed formwork 03: Electrode insulator 04: Current / voltage signal converter 11: Common electrode (A) 12: Electrode (B) 13: Electrode (B) 14: Electrode (B) ) 21: Common electrode (A) 22: Electrode (Otsu) 23: Electrode (Otsu) 24: Electrode (Otsu) I: Current M: Concrete injection port N: Injection concrete envelope P: Repose angle S: Virtual short-circuit conductor SW: Input signal switch GL: Ground level

Claims (3)

[Claims] 1. In construction and civil engineering concrete pouring work, in order to detect whether or not concrete has been filled and placed in a predetermined section, mounting holes are drilled in a concrete formwork to be assembled and used on site, and different types are constructed. Attach the metal shell and the metal shell to the most suitable position for work and concrete quality control through an insulator, connect these to a signal converter, and configure a detection circuit for the presence of concrete before solidification. A device for detecting a concrete placing section, which is characterized by being able to do. 2. A water content meter for a surface layer portion of concrete after pouring, using the construction of the concrete detecting device according to claim 1. 3. A concrete pouring method in which an electrode can be easily inserted into the concrete pouring formwork described in claim 1 and an electrode mounting hole is closed by a material which can serve as an insulator when the electrode is inserted. Formwork for.