JPH06172059A - Rupturing prevention method of high-strength concrete - Google Patents
Rupturing prevention method of high-strength concreteInfo
- Publication number
- JPH06172059A JPH06172059A JP32813892A JP32813892A JPH06172059A JP H06172059 A JPH06172059 A JP H06172059A JP 32813892 A JP32813892 A JP 32813892A JP 32813892 A JP32813892 A JP 32813892A JP H06172059 A JPH06172059 A JP H06172059A
- Authority
- JP
- Japan
- Prior art keywords
- concrete
- strength concrete
- strength
- rupturing
- prevention method
- 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.)
- Granted
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)
Abstract
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 Explosion phenomenon of a concrete structure occurs when free water in the concrete becomes high-pressure steam at high temperature, becomes larger than the tensile strength of the concrete, destroys the concrete, and the steam is released to the atmosphere. It is a phenomenon that scatters concrete. With conventional ordinary concrete,
The explosive phenomenon rarely 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 it is difficult to dissipate water vapor at high temperature and the explosion phenomenon easily occurs due to its dense quality.
【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。SUMMARY OF THE INVENTION Therefore, 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型枠を外
し、コンクリート構造物の表面を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 reached the present invention by studying the idea that the explosion phenomenon can be prevented by bringing only the structure near the surface of a high-strength concrete structure closer to ordinary concrete. . That is, the present invention is a method for preventing explosion of high-strength concrete, which comprises placing concrete in a formwork, removing the initial formwork of the hardening process of the concrete, and rapidly cooling the surface of the concrete structure.
【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。When the surface of a high-strength concrete structure is rapidly cooled according to the present invention, the vicinity of the surface of the concrete tends to shrink rapidly, whereas the interior of the concrete cannot be cut off due to the shrinkage, and therefore, the area near the surface of the concrete is visually impaired. It is considered that a large number of fine cracks that cannot be seen are generated. It is considered that the cracks improve the air permeability of the high-strength concrete structure and improve the dissipation of water vapor inside the concrete structure to the outside, and prevent the explosion phenomenon. The cracks in the vicinity of the surface of the high-strength concrete structure are closed as the hardening progresses and the inside of the structure cools, so that the strength of the structure is not adversely affected.
【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°Ｃ
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, a large amount of heat of hydration reaction is generated, and the surface temperature is 60 ° C. in the early stage of the hardening process (about 1 to 3 days after placing).
It is usually over. Therefore, at this time, the mold can be removed, and cold water can be continuously sprayed on the surface of the concrete for several minutes to rapidly cool the surface of the concrete according to the present invention. On the other hand, if the surface temperature of the concrete is lowered at this time, the stronger cooling agent such as liquid nitrogen or dry ice may be sprinkled to quench it.
【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°Ｃであった。型枠を外し、コンクリート
の表面に１０°Ｃ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 cast into a 1 m × 1 m × 3 m columnar mold. The surface temperature of the concrete was 70 ° C. 2 days after the casting. The mold was removed, and cold water at 10 ° C was continuously sprayed on the surface of the concrete for 5 minutes. After leaving the concrete at room temperature for one month, it was placed in a fireproof test furnace and heated for 15 minutes in accordance with the fireproof 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 phenomenon of high-strength concrete can be prevented by a simple method of rapidly cooling the surface of high-strength concrete in the early stage 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. A method of preventing explosion of high-strength concrete, which comprises placing concrete in a formwork, removing the formwork in the early stage of hardening of the concrete, and rapidly cooling the surface of the concrete structure.
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 true JPH06172059A (en) | 1994-06-21 |
| JP2720739B2 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 |
|---|---|
| JP2720739B2 (en) | 1998-03-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| ATE219155T1 (en) | FIREPROOF WALL STRUCTURE | |
| US3006046A (en) | Hot top for ingot mold and method of making the same | |
| JPH06172059A (en) | Rupturing prevention method of high-strength concrete | |
| JP2879005B2 (en) | Cooling method of casting | |
| JPS62122710A (en) | Mixer for cooling concrete | |
| Jafari et al. | Effect of thickness and permeability of ceramic shell mould on in situ melted AZ91D investment casting | |
| US3977915A (en) | Method of heat treating metal parts | |
| JP2937749B2 (en) | Freezing mold casting method | |
| CA2071902A1 (en) | Method of controlling the rate of heat extraction in mould casting | |
| JP6143008B2 (en) | Pressurized steam aging method for steelmaking slag | |
| US1325725A (en) | Consin | |
| KR100779121B1 (en) | Filler for ladle receiving molten steel | |
| JPH0445264B2 (en) | ||
| US3508600A (en) | Process of casting with mold stool protection plate | |
| Itofuji et al. | Development of Semi-Solid Die Casting Process in Spheroidal Graphite Cast Irons | |
| US3613209A (en) | Process for manufacturing gold alloy watch casings | |
| JPH05239547A (en) | Manufacture of high tension steel material | |
| US788131A (en) | Method of manufacturing refractory material. | |
| US2221526A (en) | Process for heat treating aluminum alloys | |
| SU64528A1 (en) | Method of making cast molds | |
| JPS5791850A (en) | Graphite casting mold for horizontal and continuous casting of cast iron plate | |
| RU2116157C1 (en) | Method for melting out of patterns from shell molds | |
| JPH08312139A (en) | Temperature crack preventive method of mass concrete | |
| JPS6349698A (en) | Method of executing lining refractory of vessel for high-temperature melt | |
| JPH05194042A (en) | Sealing material |
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 |