JPH095286A - Potential measuring mark sheet and method for measuring potential of reinforcing bar therewith - Google Patents

Abstract

PURPOSE: To provide a means which unnecessitates marking and enables quick and accurate measurement. CONSTITUTION: A mark sheet 1 wherein a grid pattern such as grid points or squares of specified dimension showing the measuring positions of natural potential is printed or written on a woven or unwoven cloth in a water-insoluble oil-based ink, etc., is adhered to the surface of a reinforced concrete as an object to be measured for natural potential, and a reference electrode 6 which is cylindrical or of rotary type for measuring natural potential is brought into contact with the surface of the sheet 1. Then, one end of a lead wire of the electrode 6 is connected with the minus terminal of a potentiometer, while one end of a lead wire connecting to the reinforcing bar is connected with the plus terminal thereof, realizing such a measuring state for natural potential. Thus only scanning on the mark enables quick and accurate measurement without applying marking in advance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a large amount of self-potential for directly evaluating the corrosiveness of reinforcing bars in reinforced concrete such as concrete bridges, highway bridges or tunnels with high efficiency and directly on the concrete surface. The present invention relates to a potential measuring mark sheet that can be used without writing measurement points and a reinforcing bar potential measuring method using the mark sheet.

[0002]

2. Description of the Related Art A conventional method for measuring the self-potential of a reinforcing bar in concrete is to directly measure the concrete surface 3 to be measured with a marker or a chalk as shown in FIG. For the purpose of improving the case where the concrete surface is highly dry or electrically insulated so that the very surface of the concrete interferes with the measurement of the self-potential, tap water etc. on the concrete surface in advance. Prepare the measurement environment of the measurement surface by spraying or spraying water.

FIG. 5 is a cross-sectional view of the cross 9 shown in FIG.
It shows a method of measuring the spontaneous potential at a measuring point, and a lead wire with a clamp 7 for connecting a cylindrical reference electrode 11 such as a copper sulfate electrode to the negative terminal of the digital potentiometer 10 and a reinforcing bar 4 to the positive terminal. 8 is connected, and a cloth or sponge 13 impregnated with an electrolyte such as water is interposed between the concrete surface 12 and the cylindrical reference electrode 11 for measurement.

[0004]

In the prior art, however, marking a large number of measuring points on the grid 9 with a tape measure or the like requires a great deal of labor and a large amount of measuring time. Not only that, when a marker is used for marking, the concrete surface is soiled, and when chalk is used, the marked measuring points disappear by spraying or spraying water. Further, the contact of the verification electrode 11 with the sponge 13 interposed is
Since the water content of the sponge 13 is different due to individual differences and the measurement time becomes very long, the water content of the concrete changes every moment, and the spontaneous potential value changes accordingly, so stable and appropriate data can be obtained. There was a problem that it required excellent experience to obtain it.

The present invention has been made in view of the above circumstances and does not perform marking work on concrete which requires a great amount of working time, does not stain the concrete surface, and moreover makes it almost uniform on the concrete surface. It is an object of the present invention to provide a potential measurement mark sheet that has achieved a water-containing state and a reinforcing bar potential measurement method using the mark sheet.

[0006]

In order to achieve the above object, the potential measuring mark sheet of the present invention has a water-absorbing sheet in which water is provided with grid points or grid patterns of a predetermined size indicating the potential measuring position in advance. It is printed or written with insoluble ink or the like. It is good that the sheet is a woven or non-woven fabric of cotton or synthetic fiber.

According to the method for measuring the electric potential of a reinforcing bar of the present invention, a mark sheet for measuring electric potential having a predetermined area, which is substantially uniform and contains an appropriate amount of water, is brought into contact with the concrete surface, and the negative electrode of the voltmeter is provided with a reference electrode and the positive terminal is provided with a reinforcing bar. The connection is made, and the potential of the reinforcing bar is measured in a grid pattern by individually or continuously moving the reference electrodes from the measurement origin of the grid coordinates of the mark sheet so as to contact the surface of the mark sheet.

[0008]

[Function] On a cloth made of cotton or synthetic fiber that has high moisture absorption and water absorption and low shrinkage, print or write grid-like measurement points according to the measurement conditions in advance with oil-based ink or magic and The potential measurement mark sheet that can get an almost uniform water content by immersing the cloth in water, squeezing it so that it does not drip, and applying it to the concrete surface is a great work time required for the conventional marking process. In addition, the water content of the concrete surface is shielded by the sheet and kept almost constant because the water content of the concrete surface is fixed and fixed by contacting with the concrete surface in an appropriate water content state. Etc. can be measured. In particular, the use of a rotary collation electrode and a potentiometer built in a computer that enables the storage and storage of measured potentials makes the measurement work quicker than the usual 30 times more efficient.

[0009]

EXAMPLE An example will be described with reference to the drawings. In FIG. 1, as the nonwoven fabric of the synthetic fiber used for the material of the mark sheet 1, polyester-based, acrylic-based or other synthetic fiber can be used. For example, polyester-based Aire E1100 manufactured by Asahi Kasei, acrylic-based Unitika 109
06WTD and the like. The same woven fabric as the non-woven fabric can be used.

The cotton cloth, the woven cloth or the non-woven cloth of the synthetic fiber used for the mark sheet 1 should be sufficiently washed in advance with tap water or the like so as to hardly shrink. After the mark sheet 1 is dried, a grid pattern is drawn in advance with a water-insoluble oily marker in consideration of the measurement interval. The grid pattern is produced by drawing the lower left portion of the dry mark sheet 1 as the origin (0, 0) of the X, Y coordinates, that is, the measurement starting point 2, and drawing lines at intervals of 5 cm in the X direction and at intervals of 25 cm in the Y direction. .

In the figure, a0 is the guide line of the first rotary collation electrode capable of measuring a maximum of 5 points in the first stage in the Y-axis direction, and a19 is Y.
The guide line of the last rotary verification electrode that can measure up to 5 points in the first axial direction, d0 is the guide line of the first rotary verification electrode that can measure up to 5 points in the fourth axial direction, and d19 is Y Axial direction 4
It is the guide line of the last rotary reference electrode that can measure up to 5 points in the step.

FIG. 2 shows that the mark sheet 1 previously dipped in water is squeezed on the surface of the provided reinforced concrete test body 15 (100 cm × 100 cm × 20 cm) until the water does not drip.
It shows a state of being installed at a predetermined position on the measurement surface of the reinforced concrete test body 15. In the illustrated example, since the mark sheet 1 is installed on the plane upper surface, it is not necessary to fix the mark sheet 1 in particular, but the mark sheet 1 can be applied to other embodiments not shown, for example, the vertical surface or the horizontal back surface of the concrete structure.
Is fixed with insulating (plastic) tacks, etc., and especially on the horizontal back surface, in consideration of workability, attach the edge of the mark sheet 1 to a thin wooden frame or plastic frame of a specified size with tacks. Measurement is performed by fixing the integrated structure to the concrete surface with insulating (plastic) tacks or the like on the concrete surface.

FIG. 3 is a side view in the Y direction of FIG. 2, showing one side surface during actual measurement of the natural potential using the mark sheet 1. The potentiometer 5 used in this embodiment has a built-in computer so that the data acquisition interval can be freely set, and data can be stored, stored and transferred. 6 (for example, Japanese Unexamined Patent Publication No. 4-184249) has a built-in collation electrode and a sensor for detecting a rotation distance, and the collation electrode rotates on the mark sheet 1 and continuously forms a grid at designated intervals. The spontaneous potential data is captured in a similar manner.

In the figure, 7 is a clamp and 8 is a lead wire.

[0015]

Since the present invention is configured as described above, it has the following effects. Since the mark sheet is used, not only does the grid pattern be written directly on the concrete surface and the concrete surface is not polluted, but the measurement time is reduced to about one-third of the conventional one and stable data such as the self-potential is obtained. Obtainable.

[0016] In general, in the concrete in the atmosphere, the very surface is often so dry that it interferes with the measurement of the rebar potential. When applying and measuring, tap water or the like must be sprayed on the concrete surface as evenly as possible in advance, but if the mark sheet according to the present invention is used, the effect of preventing the evaporation of spray water by the shielding effect of the mark sheet There is.

[Brief description of drawings]

FIG. 1 is a plan view of a mark sheet of the present invention.

FIG. 2 is a three-dimensional view of an example in which the mark sheet of the present invention is installed on the surface of a concrete specimen.

FIG. 3 is a side view of FIG. 2 showing a method for measuring the electric potential of a reinforcing bar of the present invention.

FIG. 4 is a front view showing an example of a conventional measurement position writing method.

FIG. 5 is an explanatory diagram of a conventional potential measuring method.

[Explanation of symbols]

 1 Mark Sheet 2 Measurement Start Point 3 Concrete Surface 4 Reinforcing Bar 5 Potentiometer 6 Rotating Verification Electrode 7 Clamp 8 Lead Wire 9 Cross Grid 10 Digital Potentiometer 11 Cylindrical Verification Electrode 12 Concrete Surface 13 Sponge 15 Reinforced Concrete Specimen

Claims (3)

[Claims] 1. A mark sheet for potential measurement, which is characterized in that a grid point or a grid pattern having a predetermined size indicating a potential measurement position is printed or written in advance with a water-insoluble ink or the like on a sheet having water absorbability. 2. The mark sheet for potential measurement according to claim 1, wherein the sheet is a woven or non-woven fabric of cotton or synthetic fiber. 3. The potential measuring mark sheet according to claim 1, which has a substantially uniform and appropriate amount of water and has a predetermined area, is brought into contact with the concrete surface, and a reference electrode is connected to the negative terminal of the voltmeter and a reinforcing bar is connected to the positive terminal. Then, the potential of the reinforcing bar is measured in a grid-like manner by individually or continuously moving the reference electrode from the measurement origin of the grid coordinates of the mark sheet so as to contact the surface of the mark sheet.