KR20120073056A - Device measuring corrosion rate of steel in concrete - Google Patents

Abstract

PURPOSE: A device for measuring a corrosion degree of a rebar is provided to enhance the availability of utilizing equipment by easily and rapidly performing desired functions because a corrosion degree of a rebar is measured by directly reading following what the screen displays without a manual and touching the screen. CONSTITUTION: A device for measuring a corrosion degree of a rebar comprises a half-cell sensor(12), a grounding clamp(11), and an potential difference measuring part(13). The half-cell sensor comprises a sponge contacting to a concrete structure which is a measurement object as a humid material. The half-cell sensor uses an electrochemistry reaction. The grounding clamp has conductivity. The potential difference measuring part measures a corrosion degree of a rebar of a reinforced concrete structure using a potential difference of the half-cell sensor contacting to a surface of the reinforced concrete structure. .

Description

Device measuring corrosion rate of steel in concrete

The present invention relates to a reinforcing bar corrosion measuring apparatus, and more particularly to a reinforcing bar corrosion measuring apparatus for quantitatively measuring the reinforcing steel corrosion of the reinforced concrete structure.

Reinforced concrete, which is most widely used in building and civil engineering structures, is an economical and durable structural material.

Until now, it has been a common perception that reinforced concrete has a service life of about half a century, so that reinforced concrete structures have been used for that period without special maintenance.

In fact, reinforced concrete combined with concrete and rebar is known as a composite material having an optimal function not only in terms of mechanical strength but also in terms of long-term durability.

However, recent research results and field surveys show that reinforced concrete degrades durability due to corrosion of reinforcing bars, causing serious problems throughout the structure.

The biggest deterioration in the durability of reinforced concrete structures is the corrosion of buried reinforcing bars, and the main causes of corrosion of reinforcing bars are chlorine ions and carbon dioxide penetrating from inside or outside.

Once the steel is corroded, corrosion products are formed on the surface of the steel to cause cracking and peeling of the concrete. These cracks and peelings facilitate the penetration of external harmful factors to accelerate the corrosion of the steel.

Therefore, the safety and durability of the reinforced concrete structure is greatly reduced, and in severe cases the reinforced concrete structure may lead to collapse. In addition, if the reinforced concrete structure is already damaged, repairing and reinforcing it is very difficult, limited and economically expensive.

Therefore, there is a need for a method to evaluate the condition of reinforced concrete structures by quantitatively measuring the corrosion of reinforced concrete structures and to predict the appropriate repair time.

The present invention is to solve the above problems, an object of the present invention is to provide a reinforcing bar corrosion measuring apparatus for quantitatively measuring the corrosion of the reinforced concrete structure to evaluate the state of the reinforced concrete structure and predict the appropriate time to repair.

In order to achieve the above object, the present invention includes a half-cell sensor comprising a sponge in contact with the reinforced concrete structure to be measured as a wet material and a sensor using an electrochemical reaction; A conductive ground clamp in contact with the rebar exposed from the reinforced concrete structure; And a potential difference measurer configured to measure reinforcing corrosion of the reinforced concrete structure by a potential difference between the ground clamp contacting the exposed rebar and the sponge sensor contacting the surface of the reinforced concrete structure through the sponge. do.

The present invention according to the above problem solving means, by measuring the reinforcement corrosion of the reinforced concrete by the reinforcement corrosion measuring device measured by the potential difference between the reference electrode on the reinforced concrete surface and the relative voltage of the reinforcing steel reinforced concrete structure It provides the effect of safe management.

In addition, the half-cell sensor of the reinforcing bar corrosion resistance device is a wet material, because it is in contact with the reinforced concrete using a sponge having excellent absorbency and water repellency that can be kept wet by capillary action, the conductivity between the reinforced concrete and the half-cell sensor This gives the effect of being improved.

Furthermore, since the potentiometer of the rebar corrosion measuring apparatus includes a touch screen, the rebar corrosion measurement can be performed easily and quickly by directly reading and touching the screen according to the display on the touch screen without a manual, so that a desired function can be easily and quickly operated. It provides the effect of improving the ease of operation of the equipment.

In addition, since the rebar corrosion measuring apparatus uses a Secure Digital (SD) memory card, it provides an effect that data is easily stored, recalled, and checked.

1 is a view showing a reinforcing bar corrosion measuring apparatus according to an embodiment of the present invention.
Figure 2 is a perspective view of the half cap half sensor of Figure 1;
3 is a block diagram illustrating the potential difference measuring unit of FIG. 1.
Figure 4 (a) is a view showing the upper portion of the potential difference measuring portion of FIG.
Figure 4 (b) is a view showing one side of the potential difference measuring unit of FIG.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In general, when a chemical reaction occurs in which a product is formed from a reactant, atoms participating in the reaction undergo a change of atomic state.

When the exchange of electrons is involved in such a change of atomic state, it is called electrochemical reaction.

In general, when a metal is immersed in an electrolyte solution, a potential difference is generated between the metal and the solution, and the potential difference is called a half-cellpotential or a single electrode cell.

As shown in Figure 1, the reinforcing bar corrosion measuring apparatus according to an embodiment of the present invention to measure the reinforcing bar corrosion by the ground clamp 11, the half-cell sensor 12 and the potential difference between the half-cell sensor and the ground clamp It includes a potentiometer 13.

The ground clamp 11 includes a tong 21 of a conductor that can be easily grounded with a reinforcing bar, and a handle member 22 of an insulator in which a plastic tube is covered on a handle portion of the tong 21.

1 and 2, the half-cell sensor 12 is a sensor using an electrochemical reaction between a copper sulfate and a copper sulfate solution, and has a cylindrical shape having a non-conductor, a space therein, and outer spiral portions formed at outer peripheral surfaces at both ends thereof. Sensor case 31; An upper cap 32 formed at an upper portion of the outer spiral portion and a spiral portion corresponding to each other and coupled to one side of the sensor case 31; A lower cap 33 formed at an upper portion of the outer spiral portion and a spiral portion corresponding to each other and coupled to the other side of the sensor case 31; The BNC, which penetrates the bottom of the upper cap 32 and has one end inside the upper cap 32, the other end protruding from the upper cap 32, and the other end thereof is connected to the potentiometer 13 through a cable. Bayonet neil concelman connector 34; A saturated copper sulfate solution 35 inside the sensor case 31; Copper, which is connected to one end of the BNC connector 34 located inside the upper cap 32, protrudes outward from the upper cap 32, and is immersed in a saturated copper sulfate solution 35 inside the sensor case 31 to cause electrode decomposition. Round bar 36; A sponge (37) which penetrates a bottom portion of the lower cap (33) as a wetting material of the half-cell sensor (12), the one end of which is formed inside the lower cap (33), and the other end of which protrudes from the lower cap (33); And a stainless steel net 38 mounted on one end of the sponge 37 positioned in the lower cap 33.

The sensor case 31 is formed to be transparent such as a transparent acrylic tube so as to easily check whether the copper sulfate solution 35 is saturated.

The copper sulfate solution 35 is a conductive copper sulfate solution in which reagent grade copper sulfate crystal powder is dissolved in distilled or deionized water.

The sponge 37 is formed of a special material such as PVA (Poly Vinyl Alcohol) having excellent absorbency and water repellency, a porous wet sports towel, and is kept wet by a capillary phenomenon.

And the special material of the sponge 37 is easy to process the sensor case 31 and components.

In addition, the sponge 37 is a liquid bridge having a small electric resistance between the surface of the reinforced concrete to be measured and the half-cell sensor 12, and is excellent in conductivity because it maintains a wet state.

As shown in FIGS. 1, 3, 4 (a) and 4 (b), the potentiometer 13 is a portable device having excellent grip, and has an upper center portion of the potentiometer 13. Reinforcing ground member of the positive terminal (+) of the positive terminal which is formed in and connected to one of the handle member 22 of the handle member 22 of the ground clamp 11 to receive the potential value of the rebar grounded to the ground clamp 11 ( 41); The sensor input member 42 of the negative terminal (-), which is formed on one side of the reinforcement ground member 41 above the potential difference measuring unit 13 and is connected to the BNC connector 34 to receive the potential value of the half-cell sensor 12. ); An amplifying member (43) for amplifying the potential difference input through the reinforcing ground member (41) and the sensor input member (42) twice and level shifting to a positive voltage; An A / D converter 44 for converting an analog value amplified by the amplifying member 43 and level shifted with a positive voltage into a digital value; A storage unit 45 for storing the digital values; An LED unit 46 formed on the front side of the potential difference measuring unit 13 to display a low battery; A touch screen 47 formed above the LED unit 46 at the front side of the potential difference measuring unit 13 to display the digital values; Control unit 48 that collectively controls the potential difference measuring unit 13, including the amplifying member 43, A / D converter 44, storage unit 45, LED unit 46 and the touch screen 47 ; And a power supply unit 49 that provides an operating power source of the potential difference measuring unit 13.

In addition, the potential difference measurer 13 may upgrade the firmware.

The potentiometer 13 has a measurement range of -600 Hz to 600 Hz, with a resolution of 3 mV and an operating temperature of -20 ° C to 70 ° C.

As the A / D converter 44, ARM7 {A / D (10 bits, 3.3V, about 72 MHz)} or the like is used.

The storage unit 45 is a 64MB SDRAM, an SD (Secure Digital) memory card 51 inserted into one side of the potential difference measuring unit 13, or the like.

The LED unit 46 also displays read / write operations of the SD memory card 51.

The touch screen 47 is a 4.3-inch TFT-LCD or the like with a touch sensor, and is directly clicked on the screen as displayed on the screen.

The power supply unit includes a power switch 52 formed at the other side of the reinforcing bar member 41 above the potential difference measuring unit 13; And a charger (not shown) and an overcurrent / overcharge protection circuit that charges through the sensor input member 42.

The power supply unit may include a disposable battery or a battery capable of heavy charging, and preferably, may be a 7.4V lithium ion battery that can be charged.

Referring to the operation of the reinforcing bar corrosion measurement apparatus according to an embodiment of the present invention described above are as follows.

First, in order to conduct conduction from the negative electrode sensor 12, which is the negative pole, to the ground clamp 11, which is the positive pole, the concrete interior of the reinforced concrete to be measured with clean water (not shown) is moistened and reinforced. It increases the conductivity between concrete and concrete.

The clean water is only for allowing current to flow inside the concrete.

In addition, the ground clamp 11 is connected to the rebar exposed by a method such as drilling a hole in the concrete, and is connected to the reinforcing ground member 41 which is a positive terminal of the potential difference measuring unit 13.

Subsequently, the sponge 37 of the half-cell electrode 12 is in contact with the concrete, and the BNC connector 34 of the half-cell electrode 12 is a negative input terminal of the potential difference measuring unit 13. It is connected with 42.

As described above, the reinforcing bar electrically connected to the reinforcing bar member 41, which is the positive terminal of the potential difference measuring unit 13, and the sensor input member 42, which is the negative terminal of the potential difference measuring unit 13. An electric circuit is constituted by the half-cell electrode 12 electrically connected to the second electrode 12, and it is determined whether or not the corrosion of the reinforced concrete of the reinforced concrete to be measured is measured based on the result of measuring the potential difference measuring unit 13.

The determination of the corrosion of the reinforcing bar is shown in Table 1 below.

Corrosion rating Natural potential E ( mV ) Corrosion Probability P (%) I E> -200 More than 90% chance of no corrosion Ⅱ -200 ≥ E> -350 Unclear Ⅲ -350 ≥ E More than 90% chance of corrosion

The rebar corrosion measuring apparatus according to the embodiment of the present invention described above is used irrespective of the diameter of the rebar or the thickness of the concrete coating.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited to the drawing.

11: ground clamp 12: half-cell sensor
13: potentiometer 21: clamp
22: handle member 31: sensor case
32: upper cap 33: lower cap
34: BNC connector 35: Copper sulfate solution
36: copper round bar 37: sponge
38: stainless steel network 41: steel reinforcing member
42: sensor input member 43: amplification member
44: A / D converter 45: storage unit
46: LED portion 47: touch screen
48: control unit 49: power supply unit

Claims (7)

A half-cell sensor 12 including a sponge 37 in contact with a reinforced concrete structure to be measured as a wet material and a sensor using an electrochemical reaction;
A conductive ground clamp 11 in contact with the rebar exposed from the reinforced concrete structure; And
Measuring the reinforcing corrosion of the reinforced concrete structure by the potential difference between the ground clamp 11 in contact with the exposed rebar and the sponge sensor 12 in contact with the surface of the reinforced concrete structure through the sponge 37 Rebar corrosion measurement device characterized in that it comprises a potentiometer (13). The method of claim 1,
The ground clamp 11 includes a tong 21 of a conductor that is easily grounded with the exposed rebar, and a grip member 22 of an insulator in which a plastic tube is covered on a grip portion of the tong 21. Rebar corrosion measurement device. The method of claim 1,
The half-cell sensor 12 includes a cylindrical sensor case 31 having a non-conductor, a space therein, and outer spiral portions formed on outer peripheral surfaces of both ends thereof; An upper cap 32 formed on an upper side of the outer spiral part and a spiral part corresponding to each other and coupled to one side of the sensor case 31; A lower cap 33 formed at an upper portion of the outer spiral portion and a spiral portion corresponding to each other and coupled to the other side of the sensor case 31; One end of the upper cap 32 penetrates the bottom of the upper cap 32 and the other end protrudes from the upper cap 32 to the outside, and the other end of the upper cap 32 is connected to the potentiometer 13 and the cable. A BNC connector 34 connected; A saturated copper sulfate solution 35 inside the sensor case 31; It is connected to one end of the BNC connector 34 located inside the upper cap 32, protrudes from the upper cap 32, and is immersed in a saturated copper sulfate solution 35 inside the sensor case 31 to disassemble the electrode. Copper ring bar 36 causing; A sponge 37 penetrating a bottom portion of the lower cap 33 and having one end formed inside the lower cap 33 and the other end protruding from the lower cap 33 to the outside; And a stainless steel net (38) mounted on one end of the sponge (37) located inside the lower cap (33). The method of claim 1,
The half-cell sensor 12 is a reinforcing bar corrosion measuring apparatus, characterized in that the sensor using the electrochemical reaction of copper and copper sulfate solution. The method of claim 1,
The potentiometer 13 is a portable device having an excellent grip, and is formed at the upper center portion of the potentiometer 13 and is one of the handle members 22 of the ground clamp 11. A reinforcing ground member (41) of the positive terminal connected to the ground clamp (11) to receive a potential value of the reinforcing steel grounded to the ground clamp (11); A sensor input member of a negative (-) terminal formed on one side of the reinforcing ground member 41 above the potential difference measuring unit 13 and connected to the BNC connector 34 to receive a potential value of the half-cell sensor 12. (42); An amplifying member (43) for amplifying the potential difference input through the reinforcing ground member (41) and the sensor input member (42) twice and level shifting to a positive voltage; An A / D converter 44 for converting an analog value amplified by the amplifying member 43 and level shifted with a positive voltage into a digital value; A storage unit 45 for storing the digital values in the SD memory card 51 and the SDRAM; An LED unit 46 formed on a front surface of the potential difference measuring unit 13 and displaying a read / write operation of a low battery and the SD memory card 51; A touch screen (47) formed above the LED unit (46) of the front portion of the potential difference measuring unit (13) and displaying the digital values to the outside; The amplification member 43, the A / D converter 44, the storage unit 45, the LED unit 46 and the touch screen 47 including the overall control of the potentiometer 13 A control unit 48; And a power supply unit (49) for providing an operating power source of the potential difference measuring unit (130). The method of claim 1,
The potentiometric measuring unit has a measuring range of -600㎷ to 600㎷, resolution is 3mV, operating temperature is -20 ℃ ~ 70 ℃ characterized in that the corrosion corrosion apparatus. The method according to claim 6,
The power supply unit includes a power switch 52 formed on the other side of the reinforcing bar member 41 above the potential difference measuring unit 13; Reinforcing bar corrosion resistance device characterized in that it comprises a charger and an overcurrent / overcharge protection circuit for charging through the sensor input member (42).

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