JP2720739B2 - How to prevent explosion of high-strength concrete - Google Patents
How to prevent explosion of high-strength concreteInfo
- Publication number
- JP2720739B2 JP2720739B2 JP32813892A JP32813892A JP2720739B2 JP 2720739 B2 JP2720739 B2 JP 2720739B2 JP 32813892 A JP32813892 A JP 32813892A JP 32813892 A JP32813892 A JP 32813892A JP 2720739 B2 JP2720739 B2 JP 2720739B2
- Authority
- JP
- Japan
- Prior art keywords
- concrete
- strength concrete
- strength
- explosion
- prevent explosion
- 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 - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/02—Selection of the hardening environment
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
- Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、高強度コンクリートの
爆裂防止方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing explosion of high-strength concrete.
【０００２】[0002]
【従来の技術】コンクリート構造物の爆裂現象はコンク
リート中の自由水が高温状態で高圧水蒸気となり、コン
クリートの引張強度より大となって、コンクリートを破
壊し、水蒸気が大気中に解放される際にコンクリートを
飛散させる現象である。従来の普通コンクリートでは、
コンクリートの通気性が比較的良好で乾燥し易く、自由
水が少なく、高温時の水蒸気も散逸し易いという理由で
爆裂現象が生じることは殆どなかった。しかし、最近の
高強度コンクリートは、質が緻密なため高温時の水蒸気
が散逸し難く爆裂現象が生じ易いという問題がある。2. Description of the Related Art The explosion phenomenon of a concrete structure occurs when free water in concrete becomes high-pressure steam at a high temperature and becomes higher than the tensile strength of concrete, destroying the concrete and releasing the steam to the atmosphere. This is the phenomenon that concrete is scattered. In conventional ordinary concrete,
The explosion phenomenon hardly occurred because the concrete had relatively good air permeability, was easy to dry, had little free water, and easily dissipated water vapor at high temperatures. However, recent high-strength concrete has a problem in that since its quality is dense, water vapor at a high temperature is hardly dissipated, and an explosion phenomenon easily occurs.
【０００３】[0003]
【発明が解決しようとする課題】したがって、本発明
は、高強度コンクリートの爆裂防止方法を提供すること
を目的とする。Accordingly, an object of the present invention is to provide a method for preventing explosion of high-strength concrete.
【０００４】[0004]
【課題を解決するための手段】本発明者は、高強度コン
クリート構造物の表面付近の構造のみを普通コンクリー
トに近づければ、爆裂現象を防止できるとの考えで検討
し、本発明に到達した。即ち、本発明は、コンクリート
を型枠に打設し、コンクリートの硬化過程初期に型枠を
外し、コンクリート構造物の表面を、該コンクリート構
造物の表面温度との差が６０℃以上である冷却剤を散布
して急冷することを特徴とする高強度コンクリートの爆
裂防止方法である。Means for Solving the Problems The present inventors have studied on the idea that the explosion phenomenon can be prevented by bringing only the structure near the surface of a high-strength concrete structure close to ordinary concrete, and reached the present invention. . That is, according to the present invention, concrete is poured into a formwork, the formwork is removed at an early stage of the hardening process of the concrete , and the surface of the concrete structure is removed from the concrete structure.
Spray coolant with a difference of 60 ° C or more from the surface temperature of the structure
This is a method for preventing explosion of high-strength concrete, characterized by rapid cooling.
【０００５】本発明で高強度コンクリート構造物の表面
を急冷すると、コンクリートの表面付近は急激に収縮し
ようとするのに対し、コンクリートの内部は、その収縮
に応じ切れないのでコンクリートの表面付近に目に見え
ない多数の微細なひびわれが発生すると考えられる。こ
のひびわれが高強度コンクリート構造物の通気性を良好
にし、コンクリート構造物内部の水蒸気の外部への散逸
を良好にすることとなり、爆裂現象を防止すると考えら
れる。この高強度コンクリート構造物の表面付近のひび
われは、硬化が進み構造物内部が冷えてくると閉じてし
まうので、構造物の諸強度に悪影響を及ぼすことはな
い。In the present invention, when the surface of a high-strength concrete structure is rapidly cooled, the vicinity of the concrete surface tends to shrink sharply, whereas the inside of the concrete cannot be cut off in response to the shrinkage. It is thought that a number of fine cracks that are not visible are generated. It is considered that this crack improves the permeability of the high-strength concrete structure, improves the dissipation of water vapor inside the concrete structure to the outside, and prevents the explosion phenomenon. The cracks near the surface of the high-strength concrete structure close as the structure hardens and the inside of the structure cools, so that it does not adversely affect the strength of the structure.
【０００６】高強度コンクリートは、多量のセメントを
使用するため、水和反応熱を多量に発生し、硬化過程初
期（打設後１〜３日程度）は、その表面温度が６０℃を
超すのが普通である。従って、この時期に型枠を外し、
コンクリートの表面に冷水を数分間、散布し続けること
によって本発明でのコンクリートの表面の急冷を行うこ
とができる。かりに、この時期を逸しコンクリートの表
面温度が下がっているときは、液体窒素やドライアイス
のようなより強力な冷却剤を散布して急冷してもよい。Since high-strength concrete uses a large amount of cement, it generates a large amount of heat of hydration reaction, and its surface temperature exceeds 60 ° C. in the early stage of the hardening process (about 1 to 3 days after casting). Is common. Therefore, remove the formwork at this time,
By continually spraying cold water on the concrete surface for several minutes, the concrete surface can be rapidly cooled in the present invention. On the other hand, when the surface temperature of the concrete has fallen after this time, a more powerful coolant such as liquid nitrogen or dry ice may be sprayed to quench the concrete.
【０００７】[0007]
【実施例】１m ×１m ×３m の柱状の型枠に高強度コン
クリートを打設した。打設後２日経過時コンクリートの
表面温度は７０℃であった。型枠を外し、コンクリート
の表面に１０℃の冷水を５分間にわたって散水し続け
た。コンクリートを常温で１ヶ月間放置後、耐火試験炉
に入れ、耐火試験加熱条件に準じて１５分間加熱したが
爆裂は見られなかった。EXAMPLE High-strength concrete was poured into a 1 m × 1 m × 3 m column-shaped formwork. Two days after the casting, the surface temperature of the concrete was 70 ° C. The mold was removed and the surface of the concrete was continuously sprinkled with cold water of 10 ° C. for 5 minutes. After leaving the concrete at room temperature for one month, it was placed in a fire test furnace and heated for 15 minutes in accordance with the fire test heating conditions, but no explosion was observed.
【０００８】[0008]
【発明の効果】本発明により、硬化過程初期に高強度コ
ンクリートの表面を急冷するという簡単な方法で、高強
度コンクリートの爆裂現象を防止することができる。According to the present invention, the explosion of high-strength concrete can be prevented by a simple method of rapidly cooling the surface of high-strength concrete at the beginning of the hardening process.
Claims (1)
ートの硬化過程初期に型枠を外し、コンクリート構造物
の表面を、該コンクリート構造物の表面温度との差が６
０℃以上である冷却剤を散布して急冷することを特徴と
する高強度コンクリートの爆裂防止方法1. Concrete is poured into a formwork, the formwork is removed at an early stage of the hardening process of the concrete, and the difference between the surface temperature of the concrete structure and the surface temperature of the concrete structure is 6%.
A method for preventing explosion of high-strength concrete, characterized by spraying a coolant having a temperature of 0 ° C or higher and rapidly cooling the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32813892A JP2720739B2 (en) | 1992-12-08 | 1992-12-08 | How to prevent explosion of high-strength concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32813892A JP2720739B2 (en) | 1992-12-08 | 1992-12-08 | How to prevent explosion of high-strength concrete |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06172059A JPH06172059A (en) | 1994-06-21 |
| JP2720739B2 true JP2720739B2 (en) | 1998-03-04 |
Family
ID=18206927
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32813892A Expired - Lifetime JP2720739B2 (en) | 1992-12-08 | 1992-12-08 | How to prevent explosion of high-strength concrete |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2720739B2 (en) |
-
1992
- 1992-12-08 JP JP32813892A patent/JP2720739B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06172059A (en) | 1994-06-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 19970617 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 19971021 |