JPS6156942B2 - - Google Patents
Info
- Publication number
- JPS6156942B2 JPS6156942B2 JP4288280A JP4288280A JPS6156942B2 JP S6156942 B2 JPS6156942 B2 JP S6156942B2 JP 4288280 A JP4288280 A JP 4288280A JP 4288280 A JP4288280 A JP 4288280A JP S6156942 B2 JPS6156942 B2 JP S6156942B2
- Authority
- JP
- Japan
- Prior art keywords
- specimen
- concrete
- deterioration
- thaw
- freeze
- 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
- 230000006866 deterioration Effects 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 6
- 239000013535 sea water Substances 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims 1
- 238000005498 polishing Methods 0.000 claims 1
- 238000012360 testing method Methods 0.000 description 13
- 230000008014 freezing Effects 0.000 description 6
- 238000007710 freezing Methods 0.000 description 6
- 238000010257 thawing Methods 0.000 description 6
- 230000006378 damage Effects 0.000 description 4
- 239000013505 freshwater Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000009746 freeze damage Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
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の凍結融解に対する耐久
性の検討を迅速に行うこと、ならびに凍結融解作
用によるコンクリート内部の劣化を直接に検知す
ることを目的とする。
従来のコンクリートの凍害、すなわち、凍結融
解作用による劣化の検知は例えばASTM（アメ
リカ材料試験協会規格）の凍結融解試験方法を準
用しているが、これはコンクリートの劣化の進行
状態を、主として動弾性係数の変化を基準とし、
その他、供試体の重量の変化、ならびに供試体の
長さの変化などの測定にもとづいて耐久性の検討
を行うという方法である。しかしながら、この方
法によればコンクリート内部の劣化の進行を間接
に知ることはできるが直接に検討することはでき
ない。又試験に長期間を要し、且つ試験装置が複
雑大型で、極めて高価な試験であつた。
ASTMの試験方法による場合の供試体は10×
10×40cm程度の大きさのものを使用していて大型
の試験装置であり普遍性にとぼしい欠点がある。
また、コンクリートの凍害に関する野外調査の場
合は、隅角部のごとく、外気、または水分にふれ
ることが多い個所に著しい凍害が見られ、全体的
な検知が行えず、また同一条件では部材断面が比
較的小さい場合に劣化の進行が速くなつてしまう
ことが知られている。
本発明は上述した従来のコンクリート劣化検知
方法の欠点を改善したもので、コンクリートの凍
結結融解による劣化すなわち、凍害の状態の迅速
に求めるため、供試体を小さく特に薄片状とする
ことにより、供試体の表面積を大きくして伝熱上
有利とすると共に、小規模な試験装置で短期間の
試験を可能としたものである。また、現場から採
取したコアを薄片状として試験に供することがで
きる利点がある。
次に本発明の一実施例を図に基づいて説明する
と、コンクリートの凍結融解試験用供試体として
一般に用いられている縦、横、高さがそれぞれ10
×10×40cmの供試体Ｔを図に示すごとく一辺Ａを
たとえば１cm〜２cmの厚さに切断してコンクリー
ト内部の劣化の進行を観察などによつて検討する
ことができる供試体とするとともに薄片状として
凍害に対する耐久性を迅速に判定するものであ
る。尚Ａ、Ｈ、Ｗ、Ｌは供試体の各辺であり、Ｓ
は露出した粗骨材である。
表−１は従来の10×10×40供試体と本発明方法
に基づく薄片状供試体Ｔとを水中において同時に
凍結融解試融解試験を行つた場合の劣化の状態を
比較したものである。水中凍結融解用水は淡水と
海水を用いた。表−１を参照すると淡水中凍結融
解の場合は、10×10×40cmの従来の供試体の場合
では120サイクル後においては動弾性係数の変化
が測定され劣化が進行していることがわかるが外
見上の変化は認められない。
これに対し、本発明における薄片状供試体Ｔの
場合は30サイクルでコンクリートの内部において
粗骨材とモルタルとの接触面より劣化しているこ
とがわかり内部の劣化の進行状態を観察すること
ができたとともに、40〜60サイクルでコンクリー
トがバラバラに崩壊し、コンクリートの凍結融解
による劣化を検討するための促進試験用供試体と
しても利用できることがわかつた。
また、海水中においては一層劣化の進行がはげ
しく10×10×40cmの供試体の場合はＷ／Ｃ＝70％
と80％の場合は60サイクルで原形をとどめないほ
ど劣化し、120サイクルではバラバラに崩壊し
た。Ｗ／Ｃ＝60％の場合は120サイクルで粗骨材
のハクリが著しい。これに対し本発明にかかる薄
片状供試体Ｔの場合は15サイクル以内でバラバラ
に崩壊した。以上のことから海水を用いると劣化
の進行が速いため、促進試験にも利用できること
が判明した。
The purpose of the present invention is to quickly examine the durability of concrete against freezing and thawing, and to directly detect deterioration inside concrete due to freezing and thawing action. Conventional methods for detecting concrete freeze damage, that is, deterioration due to freeze-thaw effects, are applied, for example, to the ASTM (American Society for Testing and Materials Standards) freeze-thaw test method. Based on the change in coefficient,
Another method is to examine durability based on measurements such as changes in the weight of the specimen and changes in the length of the specimen. However, according to this method, although it is possible to indirectly know the progress of deterioration inside concrete, it is not possible to directly examine it. Furthermore, the test required a long period of time, and the test equipment was complicated and large, making it an extremely expensive test. When using the ASTM test method, the specimen is 10×
It is a large test device, measuring approximately 10 x 40 cm, and has the disadvantage of being less universal.
In addition, in the case of field surveys regarding frost damage to concrete, significant frost damage is observed in areas that are often exposed to outside air or moisture, such as corners, making it impossible to detect the entire area, and under the same conditions, the cross-section of the member cannot be detected. It is known that the progress of deterioration becomes faster when the size is relatively small. The present invention improves the shortcomings of the conventional concrete deterioration detection method described above.In order to quickly determine the state of deterioration caused by freezing and thawing of concrete, that is, the state of frost damage, the present invention is made by making the specimen small and especially in the form of flakes. In addition to increasing the surface area of the specimen, which is advantageous for heat transfer, it also enables short-term testing with a small-scale testing device. Another advantage is that cores collected from the field can be made into flakes and subjected to testing. Next, one embodiment of the present invention will be explained based on the diagram.
As shown in the figure, a specimen T of × 10 × 40 cm is cut on one side A into a thickness of 1 cm to 2 cm, for example, to obtain a specimen that can examine the progress of deterioration inside the concrete by observation, etc. This test quickly determines the durability against frost damage. Note that A, H, W, and L are each side of the specimen, and S
is exposed coarse aggregate. Table 1 compares the state of deterioration when a conventional 10 x 10 x 40 specimen and a flaky specimen T based on the method of the present invention were simultaneously subjected to freeze-thaw and thaw tests in water. Freshwater and seawater were used for underwater freezing and thawing. Referring to Table 1, in the case of freezing and thawing in fresh water, in the case of a conventional specimen of 10 x 10 x 40 cm, changes in the dynamic elastic modulus were measured after 120 cycles, indicating that deterioration was progressing. No changes in appearance were observed. On the other hand, in the case of the flaky specimen T in the present invention, it was found that the inside of the concrete deteriorated from the contact surface between coarse aggregate and mortar after 30 cycles, making it possible to observe the progress of internal deterioration. It was found that the concrete disintegrated into pieces after 40 to 60 cycles, and that it could also be used as an accelerated test specimen to study the deterioration of concrete due to freezing and thawing. In addition, the deterioration progresses even more rapidly in seawater, and in the case of a 10 x 10 x 40 cm specimen, W/C = 70%.
In 80% of cases, it deteriorated to the point where it could no longer retain its original shape after 60 cycles, and fell apart after 120 cycles. When W/C = 60%, peeling of coarse aggregate is noticeable after 120 cycles. In contrast, the flaky specimen T according to the present invention disintegrated into pieces within 15 cycles. From the above, it was found that seawater can be used for accelerated tests because the deterioration progresses quickly.
【表】
以上のように本発明によれば、従来にないコン
クリートの劣化検知を小規模試験装置で迅速、簡
単かつ正確に行うことができるもので土木建築等
に多大の貢献をもたらすものである。[Table] As described above, according to the present invention, it is possible to quickly, easily and accurately detect deterioration of concrete using a small-scale test device, which is unprecedented, and it will make a great contribution to civil engineering and construction. .
第１図イ及びロは本発明の実施例にかかる供試
体を示すものである。
Ｔ１，Ｔ２…供試体、Ｓ…粗骨材。
FIGS. 1A and 1B show specimens according to embodiments of the present invention. T1, T2...specimen, S...coarse aggregate.
Claims (1)
骨材を露出させ供試体とすることを特徴とするコ
ンクリートの凍結融解劣化検知方法。 ２ 前記供試体を薄板状又はこれに類似の小部材
としたことを特徴とする特許請求の範囲第１項記
載のコンクリートの凍結融解劣化検知方法。 ３ 前記供試体を海水等これに類似の液体中に収
容せしめたことを特徴とする特許請求の範囲第１
項又は第２項記載のコンクリートの凍結融解劣化
検知方法。[Claims] 1. A method for detecting freeze-thaw deterioration of concrete, which comprises cutting or polishing concrete to expose coarse aggregate and fine aggregate to prepare a specimen. 2. A method for detecting freeze-thaw deterioration of concrete according to claim 1, wherein the specimen is a thin plate-like or similar small member. 3. Claim 1, characterized in that the specimen is contained in a liquid similar to seawater or the like.
2. A method for detecting freeze-thaw deterioration of concrete according to item 1 or 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4288280A JPS56140238A (en) | 1980-04-03 | 1980-04-03 | Detecting method for quality deterioration of concrete by freezing and thawing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4288280A JPS56140238A (en) | 1980-04-03 | 1980-04-03 | Detecting method for quality deterioration of concrete by freezing and thawing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56140238A JPS56140238A (en) | 1981-11-02 |
| JPS6156942B2 true JPS6156942B2 (en) | 1986-12-04 |
Family
ID=12648401
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4288280A Granted JPS56140238A (en) | 1980-04-03 | 1980-04-03 | Detecting method for quality deterioration of concrete by freezing and thawing |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56140238A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113834719B (en) * | 2021-08-20 | 2024-03-22 | 浙大宁波理工学院 | Cooling device and method for obtaining concrete interface transition area surface sample |
-
1980
- 1980-04-03 JP JP4288280A patent/JPS56140238A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56140238A (en) | 1981-11-02 |
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