JPH0127384B2 - - Google Patents
Info
- Publication number
- JPH0127384B2 JPH0127384B2 JP9324683A JP9324683A JPH0127384B2 JP H0127384 B2 JPH0127384 B2 JP H0127384B2 JP 9324683 A JP9324683 A JP 9324683A JP 9324683 A JP9324683 A JP 9324683A JP H0127384 B2 JPH0127384 B2 JP H0127384B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- concrete
- corrosion
- steel
- potential
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000005260 corrosion Methods 0.000 claims description 52
- 230000007797 corrosion Effects 0.000 claims description 52
- 229910000831 Steel Inorganic materials 0.000 claims description 46
- 239000010959 steel Substances 0.000 claims description 46
- 239000000463 material Substances 0.000 claims description 25
- 239000007788 liquid Substances 0.000 claims description 23
- 238000012360 testing method Methods 0.000 claims description 20
- 230000010287 polarization Effects 0.000 claims description 17
- 239000007864 aqueous solution Substances 0.000 claims description 8
- 238000001514 detection method Methods 0.000 claims description 7
- 239000011148 porous material Substances 0.000 claims description 6
- 239000003792 electrolyte Substances 0.000 claims description 3
- 239000008151 electrolyte solution Substances 0.000 claims description 3
- 230000003014 reinforcing effect Effects 0.000 description 18
- 238000000034 method Methods 0.000 description 13
- 238000005259 measurement Methods 0.000 description 11
- 239000004570 mortar (masonry) Substances 0.000 description 8
- 239000003822 epoxy resin Substances 0.000 description 6
- 229920000647 polyepoxide Polymers 0.000 description 6
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000000007 visual effect Effects 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000001066 destructive effect Effects 0.000 description 3
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical class Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- 229920001817 Agar Polymers 0.000 description 2
- 239000008272 agar Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000007799 cork Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 230000003449 preventive effect Effects 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000012780 transparent material Substances 0.000 description 1
- 238000011179 visual inspection Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
- G01N17/02—Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Ecology (AREA)
- Environmental & Geological Engineering (AREA)
- Environmental Sciences (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Description
本発明は、コンクリート中の鋼材の腐食探査方
法およびその装置に関するものである。
既存コンクリート構造物の耐久性を診断する場
合、コンクリート中の鋼材の腐食状況を適確に把
握することが重要である。そして、従来、斯る腐
食状況の調査は主として目視観察による方法がと
られてきた。すなわち、この方法はコンクリート
を斫り、鋼材を露出させて行う破壊的なものであ
る。このため、調査に手間を要するうえに腐食状
況について定性的な判断しかできないという欠点
を有している。
これに対して、コンクリート中の鋼材の腐食状
況を非破壊的に調査する方法としてコンクリート
面中の鋼材とコンクリート表面上の照合電極との
間の電位差すなわち自然電位より定量的に鋼材の
腐食状況を推定しようとする電気化学的探査方法
が提案されている。
しかしながら、自然電位は鋼材の腐食による影
響を受けるのであるが、自然電位の高低が必ずし
も上記腐食の程度と直接結びつかないため、その
値のみでは鋼材が腐食しているか否かについて判
断するには信頼性に劣しいばかりでなく、腐食状
況調査において特に重要な腐食速度については全
く推定できないという欠点を有している。
本発明は、上記従来の欠点に鑑みてなされたも
ので、コンクリート中の鋼材に試験極端子を接続
する一方、照合電極および対極を備えた可搬式電
極部を上記鋼材に沿つてコンクート表面に順次密
着させてゆき、この表面から自然電位、分極抵抗
および液抵抗の３つの電気化学的特性値を測定す
ることにより非破壊的にコンクリート中の鋼材の
腐食状況を、腐食速度も含めて定量的かつ正確に
推定することを可能としたコンクリート中の鋼材
の腐食探査方法およびその装置を提供しようとす
るものである。
次に、本発明について説明する。
はじめに、第１発明に係るコンクリート中の鋼
材の腐食探査方法について説明する。
本方法は、コンクリート中の鋼材に沿つたコン
クリート面上の各位置において、鋼材に対する自
然電位、および鋼材との間の分極抵抗、液抵抗を
測定し、これらの値を基に腐食状況を推定しよう
とするもので、このため、まず上記鋼材の露出部
に１つの電極、すなわち試験極端子を接続する一
方、２種類の電極、すなわち照合電極および対極
を備えた可搬式電極部を鋼材に沿つてコンクリー
ト面上に順次密着させてゆき、従来公知の方法に
より鋼材とコンクリート面との間に所定の電圧を
印加するか、あるいは所定の電流を流し、、自然
電位、分極抵抗および液抵抗を測定する。
これらの測定値のうち、自然電位はコンクリー
ト中の鋼材の腐食の可能性の重要な目安となり、
コンクリート面の位置に対する自然電位の勾配
は、鋼材の腐食速度を推定する目安となるもので
ある。
また、分極抵抗は上記腐食速度に反比例する
と、ともに、液抵抗は従来分極抵抗測定値の誤差
成分と見なされていたのであるが、本方法では鋼
材の錆、被膜およびかぶりコンクリートの電気抵
抗の和として捉え、鋼材の腐食状況の推定に用い
ている。すなわち、液抵抗が小さい部分は、かぶ
りコンクリートの透水性が大きい場合などを含
め、一般的に錆が進行しやすい状況にあるといえ
る。
以上の前提の下に、上記測定結果より、自然電
位、分極抵抗および液抵抗の有する上記各特性の
変化を測定箇所全域にわたつて定量的かつ総合的
に調べて鋼材の腐食状況を、腐食速度を含めて推
定する。
次に、第１発明に係る方法の実施に使用するも
ので、かつ第２発明の一実施例でもある腐食探査
装置を第１図、第２図にしたがつて説明する。
図において、１は第１発明に係る腐食探査装置
で、コンクリート２中の鋼材３に接続させる試験
極端子４と、鋼材３に沿つてコンクリート２の表
面に順次密着させてゆく可搬式電極部５と、試験
極端子４および可搬式電極部５に接続した従来公
知の３電極式腐食モニタ６とからなつている。
可搬式電極部５は、透明材料からなる筒体７の
上部を、給液兼空気抜き管８を備えた上蓋９によ
り閉じてなる無底容器１０内をKCl飽和水溶液等
の電解質水溶液（以下水溶液という。）１１によ
り充し、底部を多孔質材料からなる下蓋１２によ
り閉じるとともに、照合電極１３および対極１４
を、その下部が上蓋９を貫通して水溶液１１内に
浸漬するように設けて形成したものである。上記
給液兼空気抜き管８は無底容器１０への水溶液１
１の供給ならびに液内混入空気の除去用として設
けたもので、栓付き可撓性チユーブの周囲に金属
線を巻回してなり、適宜屈曲状態で形状維持が可
能となつており、可搬式電極部５を任意の姿勢
（上向き、下向き、水平など）で使用可能となつ
ている。
また、下蓋１２は多孔質材料で出来ていること
から、常時水溶液１１により湿つた状態に保た
れ、可搬式電極部５をコンクリート２の表面に押
当てた際、この両者が密着し、電気的に良好な導
通状態となるようになつている。
なお、照合電極１３および対極１４の上部は、
外周にねじ部１７を有し、かつ給液兼空気抜き管
８を突抜けさせた上部キヤツプ１５により覆われ
る一方、可搬式電極部５の不使用時には下蓋１２
は上記ねじ部１７に螺合可能に形成した下部キヤ
ツプ１６により、保護されるとともに、水溶液１
１の蒸発防止が図られ、可搬式電極部５が持運び
易く形成されている。
ここで、上記多孔質材料としてKClを飽和させ
た寒天を含浸させたコルクが、照合電極１３とし
て飽和カロメル電極が、また対極１４として白金
電極が好適である。
一方、上記照合電極１３および対極１４は、腐
食モニタ６に持続され、自然電位、分極抵抗およ
び液抵抗の各測定値が腐食モニタ６に出力され
る。そして、これらの各値に基づいて鋼材３の腐
食状況の推定が行われる。
次に、上記構成からなる装置の操作方法につい
て説明する。
上記のように、試験極端子４をコンクリート中
の鋼材３の露出部に接続する。
ついで、可搬式電極部５を鋼材３に沿つてコン
クリート表面に順次密着させてゆき、コンクリー
ト表面の各位置における自然電位、分極抵抗、液
抵抗を腐食モニタ６により測定してゆけばよい
（第２図参照）。
次に、上記方法および装置に基く実験結果につ
いて説明する。
本実験では、以下の要領により海中曝露したモ
ルタル被覆鉄筋について自然電位の他、分極抵抗
ならびに液抵抗を測定し、各測定値と試験体の腐
食状況の目視観察の結果を調べた。
(1) 腐食探査装置
照合電極……飽和カロメル電極
対極……白金電極
下蓋……KClを飽和させた寒天を含浸させたコ
ルク
電解質水溶液……KCl飽和水溶液
(2) 試験体
試験体は、表１に示すように、
(i) モルタルに防錆剤を混入したもの（表示記
号NP）と混入しないもの（同上Ｎ）、
(ii) 表面無処理の鉄筋（同上Ｆ）、表面に亜鉛
めつき処理を施した鉄筋（同上Ｚ）および表
面にエポキシ樹脂塗装を施した鉄筋（同上
Ｅ）、
(iii) 試験体の製作時に予めモルタル表面にひび
われ（幅0.4mm）を入れたもの（同上有）と
入れないもの（同上無）、
の(i)〜(iii)項中の各１つを組合せてなるモルタル
被覆鉄筋で、海中に約１年間曝露されたもので
ある。
なお、各試験体を表１の試験体記号の欄に示
す記号（ａ、ｂ、……、ｈ）により表わすこと
とする。
The present invention relates to a corrosion detection method for steel materials in concrete and an apparatus therefor. When diagnosing the durability of existing concrete structures, it is important to accurately understand the corrosion status of steel in the concrete. Conventionally, such corrosion conditions have been investigated mainly by visual observation. In other words, this method is destructive and involves cutting away the concrete and exposing the steel. For this reason, it has the drawback that it requires time and effort to investigate and only qualitative judgments can be made regarding the corrosion situation. On the other hand, as a non-destructive method to investigate the corrosion status of steel in concrete, the corrosion status of steel can be quantitatively determined from the potential difference between the steel in the concrete surface and a reference electrode on the concrete surface, that is, the natural potential. An electrochemical exploration method has been proposed to estimate the However, although the self-potential is affected by the corrosion of steel, the height of the self-potential is not necessarily directly related to the degree of corrosion, so its value alone is not reliable in determining whether or not the steel is corroded. Not only is this method inferior in performance, but it also has the disadvantage that it is impossible to estimate the corrosion rate, which is particularly important in investigating corrosion conditions. The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and, while a test electrode terminal is connected to a steel material in concrete, a portable electrode section equipped with a reference electrode and a counter electrode is sequentially attached to the concrete surface along the steel material. By placing the steel in close contact with the surface and measuring the three electrochemical characteristic values of self-potential, polarization resistance, and liquid resistance, it is possible to quantitatively and non-destructively measure the corrosion status of steel in concrete, including the corrosion rate. The present invention aims to provide a method and apparatus for detecting corrosion of steel in concrete that enables accurate estimation. Next, the present invention will be explained. First, a method for detecting corrosion of steel in concrete according to the first invention will be explained. This method measures the natural potential of the steel, polarization resistance, and liquid resistance between the steel and the steel at each location on the concrete surface along the steel in the concrete, and estimates the corrosion status based on these values. For this purpose, one electrode, that is, a test electrode terminal, is first connected to the exposed part of the steel material, while a portable electrode section equipped with two types of electrodes, namely, a reference electrode and a counter electrode, is connected along the steel material. The steel materials are brought into close contact with the concrete surface one after another, and the self-potential, polarization resistance, and liquid resistance are measured by applying a predetermined voltage or passing a predetermined current between the steel material and the concrete surface using conventionally known methods. . Of these measurements, the self-potential is an important indicator of the corrosion potential of steel in concrete;
The gradient of the self-potential relative to the position of the concrete surface is a guideline for estimating the corrosion rate of steel. In addition, polarization resistance is inversely proportional to the corrosion rate mentioned above, and liquid resistance was conventionally considered to be an error component of polarization resistance measurement values, but in this method, the sum of the electrical resistance of steel rust, coating, and cover concrete. It is used to estimate the corrosion status of steel materials. In other words, it can be said that areas with low liquid resistance are generally in a situation where rust is likely to progress, including cases where cover concrete has high water permeability. Based on the above premise, and based on the above measurement results, we quantitatively and comprehensively investigated the changes in the above characteristics of self-potential, polarization resistance, and liquid resistance over the entire measurement area to determine the corrosion status of the steel material and the corrosion rate. Estimates include Next, a corrosion exploration apparatus which is used to carry out the method according to the first invention and which is also an embodiment of the second invention will be described with reference to FIGS. 1 and 2. In the figure, 1 is a corrosion detection device according to the first invention, which includes a test electrode terminal 4 connected to a steel material 3 in concrete 2, and a portable electrode part 5 that is brought into close contact with the surface of the concrete 2 in sequence along the steel material 3. and a conventionally known three-electrode corrosion monitor 6 connected to the test electrode terminal 4 and the portable electrode section 5. The portable electrode unit 5 has a bottomless container 10 formed by closing the upper part of a cylindrical body 7 made of a transparent material with an upper lid 9 equipped with a liquid supply and air vent pipe 8. ) 11, the bottom is closed with a lower lid 12 made of porous material, and a reference electrode 13 and a counter electrode 14 are
is formed so that its lower part penetrates through the upper lid 9 and is immersed in the aqueous solution 11. The liquid supply and air vent pipe 8 is used to supply the aqueous solution 1 to the bottomless container 10.
This tube is provided for the purpose of supplying 1 and removing air mixed in the liquid.It is made by winding a metal wire around a flexible tube with a stopper, and can maintain its shape by bending it appropriately, making it a portable electrode. The unit 5 can be used in any position (upward, downward, horizontal, etc.). In addition, since the lower cover 12 is made of a porous material, it is always kept moist with the aqueous solution 11, and when the portable electrode part 5 is pressed against the surface of the concrete 2, the two come into close contact and generate electricity. It is designed to have good electrical continuity. Note that the upper parts of the reference electrode 13 and the counter electrode 14 are
It is covered by an upper cap 15 which has a threaded part 17 on the outer periphery and has a liquid supply and air vent pipe 8 passed through it, while the lower cap 12 is closed when the portable electrode part 5 is not in use.
is protected by a lower cap 16 formed to be able to be screwed onto the threaded portion 17, and the aqueous solution 1
The portable electrode section 5 is designed to be easily carried. Here, cork impregnated with agar saturated with KCl is suitable as the porous material, a saturated calomel electrode is suitable as the reference electrode 13, and a platinum electrode is suitable as the counter electrode 14. On the other hand, the reference electrode 13 and the counter electrode 14 are maintained by the corrosion monitor 6, and the measured values of the natural potential, polarization resistance, and liquid resistance are outputted to the corrosion monitor 6. Then, the corrosion state of the steel material 3 is estimated based on each of these values. Next, a method of operating the apparatus having the above configuration will be explained. As described above, the test electrode terminal 4 is connected to the exposed portion of the steel member 3 in the concrete. Next, the portable electrode section 5 is successively brought into close contact with the concrete surface along the steel material 3, and the natural potential, polarization resistance, and liquid resistance at each position on the concrete surface are measured by the corrosion monitor 6 (second (see figure). Next, experimental results based on the above method and apparatus will be explained. In this experiment, we measured the natural potential, polarization resistance, and liquid resistance of mortar-coated reinforcing bars exposed to the sea using the following procedure, and examined the results of each measurement and visual observation of the corrosion status of the test specimen. (1) Corrosion detection device Reference electrode...Saturated calomel electrode Counter electrode...Platinum electrode Lower cover...Cork impregnated with agar saturated with KCl Electrolyte solution...KCl saturated aqueous solution (2) Test specimen The test specimen is shown in the table below. As shown in 1, (i) mortar mixed with rust preventive agent (indication symbol NP) and mortar without it (same as N), (ii) surface-untreated reinforcing bars (same as above F), surface galvanized. Treated reinforcing bars (Z above) and reinforcing bars whose surfaces are coated with epoxy resin (E above); (iii) cracks (width 0.4 mm) made in the mortar surface in advance when manufacturing the test specimen (with above) Mortar-coated reinforcing bars made of a combination of each of items (i) to (iii) of (1) and (2), which have been exposed to the sea for approximately one year. In addition, each test specimen is represented by the symbol (a, b, . . . , h) shown in the column of test specimen symbol in Table 1.
【表】
(3) 実験方法
各試験体（モルタルで被覆された部分）を湿
潤状態として、それぞれの両端部より10cmの位
置ならびに中央の計３断面について、モルタル
表面で電気化学的特性値（自然電位、分極抵抗
および液抵抗）について測定を行つた。この
他、併せてモルタルの表面ひび割れ、中性化深
さおよび鉄筋の発錆面積率の測定も行つた。
(4) 実験結果
電気化学的特性値の測定結果を第３〜５図に
示す。図中、各曲線と試験体との対応関係は以
下の通りである。
曲線記号 ……試験体
−〇− …… ａ
−△− …… ｂ
−□− …… ｃ
−×− …… ｄ
…〇… …… ｅ
…△… …… ｆ
…□… …… ｇ
…×… …… ｈ
また、第３図縦軸の目盛表示の単位mv vs
SCEは飽和カロメル電極に対する試験極の電位を
意味する。
ついで、上記モルタルの表面ひび割れ等の測定
結果を表２に示す。[Table] (3) Experimental method With each specimen (portion covered with mortar) in a wet state, electrochemical characteristic values (natural Potential, polarization resistance, and liquid resistance) were measured. In addition, surface cracks in the mortar, depth of carbonation, and rusted area ratio of reinforcing bars were also measured. (4) Experimental results The measurement results of electrochemical characteristic values are shown in Figures 3 to 5. In the figure, the correspondence between each curve and the test specimen is as follows. Curve symbol ...... Test specimen -〇- ... ... a -△- ... ... b -□- ... ... c -×- ... ... d ...〇… ... ... e ...△… ... f ...□… ... g ...× … … h Also, the unit of scale display on the vertical axis in Figure 3 is mv vs.
SCE means the potential of the test electrode relative to the saturated calomel electrode. Next, Table 2 shows the measurement results for surface cracks, etc. of the mortar.
【表】
上記測定結果より、予ひびわれを与えた場合と
与えない場合のいずれにおいても以下の事項が明
らかとなつた。
(1) 自然電位について、
(i) 著しい腐食が認められた無処理鉄筋の場合
（第３図中、−〇−、−△−、…○…、…△…
部分）と全く腐食が認められないエポキシ樹
脂塗装鉄筋の場合（同上、−×−、…×…部
分）の自然電位に殆ど差がなく、自然電位の
値だけからは腐食状況を推定することは不可
能であることがわかつた。
(ii) 亜鉛めつき処理鉄筋の場合（同上−□−、
…□…部分）については、約−800ｍＶ
vsSCEを示し、Zn→Zn2+＋2e-なる反応（電
極電位：−1007ｍＶ vsSCE）が生じている
ことが推定された。このことは目視による調
査結果によつて確認された。
(2) 分極抵抗について、
(i) 各測定位置での相違は最大値と最小値との
比が約２であり、全面腐食の状態に近いこと
が推定できる。このことは目視による腐食調
査結果によつても確認された。
(ii) エポキシ樹脂塗装鉄筋の場合（第４図中−
×−、…×…部分）は、他に比べて著しく大
きな値を示し（25〜267KΩ）、亜鉛めつき処
理鉄筋の場合（同上、−□−、…□…部分）
が次いで大きな値（0.1〜0.5KΩ）を示した。
表面無処理鉄筋の場合（同上、−○−、…〇
…、−△−、…△…部分）には、防錆剤混入
の有無による差は殆ど認められず小さな値
（0.03〜0.25KΩ）を示した。このことから、
エポキシ樹脂塗装鉄筋の場合には、全く腐食
が認められず、亜鉛めつき処理鉄筋の場合に
は、表面無処理鉄筋の場合に比べて腐食が少
なく、表面無処理鉄筋の場合には、防錆剤混
入の有無にかかわらず発錆が著しいと推定で
きる。このことは目視による腐食調査でも確
認された。
(3) 液抵抗について
エポキシ樹脂塗装鉄筋の場合（第６図中−×−
…×…部分）は、他のものに比べて約10倍の値
（6.3〜14.8KΩ）を示し、それ以外の鉄筋は略同
じ値（0.4〜1.3KΩ）であつた。この違いはエポ
キシ樹脂塗装被膜の影響によるものと考えられ
る。
なお、上記試験体を飛沫帯で曝露して、湿潤状
態および気乾状態で、上記同様の測定を行つた結
果、鋼材の腐食状況と測定値との関係は上記海中
曝露の場合と略同様の傾向を示し、特に上記湿潤
状態の場合がより近似していた。
以上の説明より明らかなように、第１発明によ
れば、自然電位、分極抵抗および液抵抗のそれぞ
れが有する電気化学的特性に基いて、鋼材に沿つ
たコンクリート表面の各位置において求めた上記
３種の測定値から鋼材の腐食状況を推定してい
る。このため、鋼材の任意の位置において、その
腐食状況を、腐食速度を含めて定量的かつ正確に
推定することが可能となる。
また、第２の発明によれば、コンクリート中の
鋼材の露出部に接続する試験極端子と、下部が多
孔質材料からなる下蓋により閉じられ、内部に電
解質水溶液で満たされるとともに、照合電極およ
び対極を有する可搬式電極部と、自然電位、分極
抵抗および液抵抗の各測定値を出力する３電極式
腐食モニターとから腐食探査装置が構成されてい
る。
このため、コンクリート中の鋼材に沿つた、コ
ンクリート表面の任意の位置において、非破壊的
に、容易かつ正確に上記鋼材の腐食状況を推定す
るための基礎データである自然電位、分極抵抗お
よび液抵抗を得ることができる等の効果を有して
いる。
この結果、既存コンクリート構造物の耐久性を
非破壊的に、容易かつ正確に把握することが可能
となり、事故発生を未然に防ぐことができる。[Table] From the above measurement results, the following points became clear in both cases with and without pre-cracking. (1) Regarding self-potential, (i) In the case of untreated reinforcing bars with significant corrosion (in Figure 3, −〇−, −△−, …○…, …△…
There is almost no difference in the self-potential between the epoxy resin-coated reinforcing bars with no corrosion observed (-x-, ... It turned out to be impossible. (ii) In the case of galvanized reinforcing bars (same as above-□-,
…□…part): approx. -800mV
vsSCE, and it was estimated that a reaction of Zn→Zn 2+ +2e - (electrode potential: -1007 mV vsSCE) was occurring. This was confirmed by visual inspection results. (2) Concerning polarization resistance, (i) The difference at each measurement position is that the ratio of the maximum value to the minimum value is approximately 2, and it can be estimated that it is close to a state of general corrosion. This was also confirmed by visual corrosion investigation results. (ii) In the case of epoxy resin-coated reinforcing bars (in Figure 4 -
×−,…×… portion) shows a significantly larger value than the others (25 to 267KΩ), and in the case of galvanized reinforcing bars (same as above, −□−, …□… portion)
showed the next largest value (0.1-0.5KΩ).
In the case of surface-untreated reinforcing bars (same as above, −○−, …〇…, −△−, …△… portions), there is almost no difference due to the presence or absence of rust preventive agent, and the value is small (0.03 to 0.25KΩ) showed that. From this,
In the case of epoxy resin-coated reinforcing bars, no corrosion is observed, in the case of galvanized reinforcing bars, there is less corrosion than in the case of surface-untreated reinforcing bars, and in the case of surface-untreated reinforcing bars, corrosion is prevented. It can be assumed that rusting is significant regardless of the presence or absence of agent contamination. This was also confirmed by visual corrosion inspection. (3) Regarding liquid resistance In the case of epoxy resin coated reinforcing bars (−×− in Figure 6)
...x... portion) showed a value (6.3 to 14.8KΩ) that was about 10 times larger than that of the others, and the other reinforcing bars had approximately the same value (0.4 to 1.3KΩ). This difference is thought to be due to the influence of the epoxy resin coating. In addition, as a result of exposing the above specimen in a splash zone and performing the same measurements as above in both a wet state and an air-dry state, the relationship between the corrosion state of the steel material and the measured value was almost the same as in the case of underwater exposure above. The results showed a similar tendency, especially in the case of the above-mentioned wet state. As is clear from the above explanation, according to the first invention, the above-mentioned three points are determined at each position on the concrete surface along the steel material based on the electrochemical characteristics of the self-potential, polarization resistance, and liquid resistance. The corrosion status of steel materials is estimated from the measured values of seeds. Therefore, it is possible to quantitatively and accurately estimate the corrosion status, including the corrosion rate, at any location on the steel material. Further, according to the second invention, the test electrode terminal is connected to the exposed portion of the steel material in the concrete, and the lower part is closed by a lower cover made of a porous material, and the inside is filled with an electrolyte aqueous solution, and the reference electrode and A corrosion exploration device is composed of a portable electrode unit having a counter electrode and a three-electrode corrosion monitor that outputs measured values of natural potential, polarization resistance, and liquid resistance. For this reason, the natural potential, polarization resistance, and liquid resistance are basic data for non-destructively, easily and accurately estimating the corrosion status of the steel material at any location on the concrete surface along the steel material in the concrete. It has the effect of being able to obtain the following. As a result, it becomes possible to easily and accurately grasp the durability of existing concrete structures in a non-destructive manner, and accidents can be prevented from occurring.
第１図は第２発明の係る腐食探査装置の断面
図、第２図は第１図に示す装置の使用状態を示す
説明図、第３図、第４図、第５図は自然電位、分
極抵抗、液抵抗の測定結果を示すグラフである。
１……腐食探査装置、２……コンクリート、３
……鋼材、４……試験極端子、５……可搬式電極
部、６……３電極式腐食モニタ、８……給液兼空
気抜き管、１０……無底容器、１１……電解質水
溶液、１２……下蓋、１３……照合電極、１５…
…対極。
Fig. 1 is a sectional view of the corrosion detection device according to the second invention, Fig. 2 is an explanatory diagram showing the usage state of the device shown in Fig. 1, and Figs. 3, 4, and 5 are self-potential, polarization It is a graph showing the measurement results of resistance and liquid resistance. 1...Corrosion detection device, 2...Concrete, 3
... Steel material, 4 ... Test electrode terminal, 5 ... Portable electrode section, 6 ... 3-electrode corrosion monitor, 8 ... Liquid supply and air vent pipe, 10 ... Bottomless container, 11 ... Electrolyte aqueous solution, 12... Lower lid, 13... Reference electrode, 15...
...the opposite.
Claims (1)
を接続する一方、多孔質材料で底部を閉じ、内部
に電解質水溶液を充填した無底容器内に照合電極
および対極を備えた可搬式電極部を、上記鋼材に
沿つてコンクリート面上に順次密着させてゆき、
コンクリート面上の各位置において、上記照合電
極、試験極および対極を用いて自然電位、分極抵
抗および液抵抗を測定し、この３つの電気化学的
特性値から鋼材の腐食状況を推定することを特徴
とするコンクリート中の鋼材の腐食探査方法。 ２ 給液部および空気抜き部を備えた無底容器の
底部を多孔質材料からなる下蓋により閉じ、かつ
容器内に電解質水溶液を満たすとともに、この電
解質水溶液に照合電極および対極を浸漬させて、
コンクリート面に密着可能に形成した可搬式電極
部と、コンクリート中の鋼材の露出部に接続させ
る試験極端子と、上記照合電極、試験極および対
極を用いて自然電位、分極抵抗および液抵抗の各
測定値を出力する３電極式腐食モニタとからなる
ことを特徴とするコンクリート中の鋼材の腐食探
査装置。[Claims] 1. A test electrode terminal is connected to an exposed portion of steel in concrete, and a reference electrode and a counter electrode are provided in a bottomless container whose bottom is closed with a porous material and filled with an electrolyte aqueous solution. The portable electrode part is successively brought into close contact with the concrete surface along the steel material,
The self-potential, polarization resistance, and liquid resistance are measured at each location on the concrete surface using the reference electrode, test electrode, and counter electrode, and the corrosion status of the steel material is estimated from these three electrochemical characteristic values. Corrosion detection method for steel in concrete. 2. Close the bottom of a bottomless container equipped with a liquid supply part and an air vent part with a lower lid made of a porous material, fill the container with an aqueous electrolyte solution, and immerse a reference electrode and a counter electrode in the aqueous electrolyte solution,
The self-potential, polarization resistance, and liquid resistance are measured using a portable electrode part that is formed to be able to adhere closely to the concrete surface, a test electrode terminal that is connected to the exposed part of the steel material in the concrete, and the above-mentioned reference electrode, test electrode, and counter electrode. A corrosion detection device for steel materials in concrete, comprising a three-electrode corrosion monitor that outputs measured values.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9324683A JPS59217147A (en) | 1983-05-25 | 1983-05-25 | Method and apparatus for inspecting corrosion of steel material in concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9324683A JPS59217147A (en) | 1983-05-25 | 1983-05-25 | Method and apparatus for inspecting corrosion of steel material in concrete |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59217147A JPS59217147A (en) | 1984-12-07 |
| JPH0127384B2 true JPH0127384B2 (en) | 1989-05-29 |
Family
ID=14077146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9324683A Granted JPS59217147A (en) | 1983-05-25 | 1983-05-25 | Method and apparatus for inspecting corrosion of steel material in concrete |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59217147A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8523553D0 (en) * | 1985-09-24 | 1985-10-30 | Colebrand Ltd | Corrosion detection |
| FI873507A (en) * | 1986-08-29 | 1988-03-01 | John B Miller | FOERFARANDE FOER LOKALISERING AV OMRAODEN PAO FOERSTAERKTA BETONGKONSTRUKTIONER, SOM AER I BEHOV AV REPARATION. |
| JPH028733A (en) * | 1988-04-04 | 1990-01-12 | Nakagawa Boshoku Kogyo Kk | Evaluation of corrosion of steel material in concrete |
| JP2511234B2 (en) * | 1993-01-26 | 1996-06-26 | 財団法人日本建築総合試験所 | Probe for detecting corrosion degree of buried rebar |
| JP2866791B2 (en) * | 1993-12-17 | 1999-03-08 | 日揮株式会社 | Buried reference electrode |
| JP3328181B2 (en) * | 1998-01-14 | 2002-09-24 | ライト工業株式会社 | Non-destructive corrosion diagnostic method for tensile steel in anchors |
| CN105628599B (en) * | 2016-02-29 | 2018-06-29 | 沈阳建筑大学 | Steel pipe concrete members in axial tension is studied in load and the device and method of performance under corrosion |
| JP6753718B2 (en) * | 2016-07-25 | 2020-09-09 | 株式会社Ｎｔｔファシリティーズ | Corrosion degree estimation method, corrosion degree estimation device and program |
| JP6753717B2 (en) * | 2016-07-25 | 2020-09-09 | 株式会社Ｎｔｔファシリティーズ | Corrosion degree estimation method, corrosion degree estimation device and program |
| JP6835279B1 (en) * | 2020-06-22 | 2021-02-24 | マツダ株式会社 | Electrode device, corrosion resistance test method for coated metal material, and corrosion resistance test device |
-
1983
- 1983-05-25 JP JP9324683A patent/JPS59217147A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59217147A (en) | 1984-12-07 |
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