【発明の詳細な説明】[Detailed description of the invention]
本発明は岩石やコンクリートなどの破砕に使用
する破壊剤に関する。
岩石やコンクリートなどの脆性物体を無騒音、
無振動で破砕する方法として、生石灰の水和反応
に伴う膨張圧を利用する方法が知られている。一
般に市販されている生石灰は軟焼生石灰であり、
活性度が高く、水和反応速度が非常に速いので、
特に10℃以上の使用環境温度の比較的高い場合、
水と練り混ぜると同時に水和反応が始まり、被破
砕物に穿孔した孔への充填作業が困難となり、使
用できなかつた。一方活性の低い硬焼生石灰を用
いても通常の粉末度では粉砕時に生じた反応活性
な微粉末生石灰が存在するので、被破砕物の孔に
充填した場合、孔からの噴出の防止と高膨張圧の
早期発現（12時間以内に300Kg／cm2以上の圧力
の発現）を両立させることが難かしいなどの欠点
があつた。特にこの傾向は破壊剤の使用環境温度
が高い場合に著しい。
本発明は上記の欠点を改良し、特に使用環境温
度の比較的高い条件においても、初期水和反応を
抑え、噴出現象がなく、適切な作業時間を確保
し、しかも短時間に破砕できる脆性物体の破壊剤
を提供するものである。
本発明者らは噴出現象について詳細に研究した
結果、下記実験例に示す如くまことに驚くべきこ
とに、使用環境温度が10℃以上の条件では、噴出
現象を発生するのは破壊剤中の微粉の生石灰であ
り、しかもこれらの微粉生石灰は膨張圧発現にあ
まり関与しないこと、さらに微粉の少ない細粒生
石灰を用いれば目的を達成できるとの知見を得て
本発明を完成するに至つた。
実験例 １
生石灰の粉末度とこれを含有する破壊剤の膨張
圧との関係
コークス炉で焼成された活性度31.5の生石灰を
小型のロツドミルで粉砕し、所定のブレーン値に
なるように調整した細粒生石灰70重量部に普通ポ
ルトランドセメント30重量部を混合し、第１表に
示される破壊剤〜を調製した。
The present invention relates to a destructive agent used for crushing rocks, concrete, etc. Noiseless removal of brittle objects such as rocks and concrete.
A known method of crushing without vibration is one that utilizes the expansion pressure associated with the hydration reaction of quicklime. Generally commercially available quicklime is soft burnt quicklime.
It has high activity and a very fast hydration reaction rate, so
Especially when the operating environment temperature is relatively high (10℃ or more),
A hydration reaction started as soon as it was mixed with water, making it difficult to fill the holes drilled in the material to be crushed, making it unusable. On the other hand, even if hard burnt quicklime with low activity is used, if it has a normal powder degree, there will be reactively active fine powder quicklime generated during crushing, so if it is filled into the pores of the material to be crushed, it will prevent ejection from the pores and cause high expansion. There were drawbacks such as the difficulty of achieving early pressure development (increase in pressure of 300 kg/cm 2 or more within 12 hours). This tendency is particularly noticeable when the environmental temperature in which the destructive agent is used is high. The present invention improves the above-mentioned drawbacks, suppresses the initial hydration reaction, eliminates the eruption phenomenon, secures appropriate working time, and can be used to crush brittle objects in a short time even under relatively high usage environmental temperatures. It provides a destructive agent for As a result of detailed research on the eruption phenomenon, the present inventors found that, surprisingly, when the operating environment temperature is 10℃ or higher, it is the fine powder in the destructive agent that causes the ejection phenomenon. The present invention was completed based on the knowledge that these finely powdered quicklime do not significantly contribute to the development of swelling pressure, and that the purpose can be achieved by using finely powdered quicklime with less fine powder. Experimental example 1 Relationship between the fineness of quicklime and the expansion pressure of the crushing agent containing it Quicklime with an activity level of 31.5 calcined in a coke oven was ground in a small rod mill, and fine powder was adjusted to a predetermined Blaine value. Destroying agents shown in Table 1 were prepared by mixing 70 parts by weight of granular quicklime with 30 parts by weight of ordinary Portland cement.
【表】
膨張圧測定試験は使用環境温度10℃の室内にお
いて以下の通り行なつた。
破壊剤を和紙製の紙袋（30φ×250Lmm）に充填
し、カプセル状にした後水中に浸漬して吸水させ
た後、膨張圧測定用鋼管へ込め棒を用いて密充填
した。破壊剤〜と、密充填したのち12時間経
過後の膨張圧との関係が図の如く得られた。
この結果、最大膨張圧が得られるのは従来破壊
剤として用いるのに不適当とされていた粉末度で
あるブレーン値で、約1200cm2／ｇの細粒生石灰を
用いた場合であることがわかつた。
実験例 ２
生石灰の粉末度とこれを含有する破壊剤の適用
上限温度との関係
使用環境温度を30〜45℃にした室内において以
下の通り試験を行なつた。
実験例１と同じようにして作製した破壊剤のカ
プセルをコンクリート供試体に設けた孔内（38φ
mm）へ密充填した。各破壊剤が試験した使用環境
温度のうち噴出を起こさなかつた最も高い温度を
適用上限温度として図に示した。
その結果、破壊剤調製に用いた細粒生石灰のブ
レーン値が小さい程適用上限温度が高くなること
がわかつた。これは生石灰の粒度が粗くなるほ
ど、水和反応が抑制されることと、水和反応熱に
よつて発生する蒸気が孔外へ抜けやすいような間
隙ができることによると考えられる。
以上実験例１〜２により破壊剤として適正な生
石灰のブレーン値は従来考えられたものより粒子
が粗い範囲にあることがわかる。
すなわち本発明の要旨は活性度20〜40の生石灰
を粉砕または分級して得られるブレーン値800〜
2000cm2／ｇの細粒生石灰を30重量％以上含んでな
る脆性物体の破壊剤にある。
本発明に使用する生石灰は活性度20〜40のもの
で、例えば生石灰やドロマイトをそれぞれ単独で
1300〜1600℃で焼成して得られるもの、あるいは
これらそれぞれにシリカ分、鉄分等の他の物質を
添加して焼成したものが挙げられる。活性度が40
を超えれば噴出現象を生じやすく、また活性度が
20未満では早期に高膨張圧を得ることができな
い。
ここでいう活性度とは、粉砕した試料より150
〜300μｍのものを50ｇ、150μｍ以下のものを50
ｇ分取し、混合した後20℃の恒温室において20℃
の水400mlを入れた容器（JIS R5203の「セメン
ト水和熱測定方法」に準じた真空ビン）に入れ連
続撹拌し10分間経過後のスラリー温度（摂氏）を
測定し、無名数として表示したものである。
本発明の破壊剤に使用する細粒生石灰の粉末度
はブレーン値で800〜2000cm2／ｇであることが必
要であるが、早期に高膨張圧を得るためには1000
cm2／ｇ以上、1500cm2／ｇ未満にすることが望まし
い。ブレーン値が2000cm2／ｇを超えれば破壊剤の
適用上限温度が低くなり、また得られる早期膨張
圧が低くなる。またブレーン値が800cm2／ｇ未満
では早期に高膨張圧が得にくく、破壊剤と水を混
練してスラリー状で使用する場合粒子の沈降を起
こしやすいので好ましくない。
破壊剤に使用する細粒生石灰のブレーン値を好
ましい範囲にするには硬焼生石灰をロツドミルの
如き粉砕機で粉砕したままでもよい場合もある
が、一般には粉砕した生石灰を適当な分級装置に
かけて好ましいブレーン値の範囲のものを収集す
ることによつて得られる。
この細粒生石灰は破壊剤中に30重量％以上含ま
れていることが必要であり、30重量％未満では得
られる膨張圧が低く実用的でない。また細粒生石
灰の量が多すぎると使用環境温度が高い場合に噴
出することがあるので、その場合には適宜減量す
る必要がある。
また本発明の破壊剤中には増量材としてポルト
ランドセメント等の水硬性物質あるいは高炉スラ
グ、フライアツシユ、石灰石粉、珪石粉等の無機
質粉が配合されるが、その量は70重量％以下にす
る必要がある。
本発明の破壊剤は反応活性の高い生石灰微粉が
少ないので噴出現象が起こりにくく、従つて使用
環境温度に応じて相対的に生石灰含有量を増すこ
とができ、早期に高膨張圧を得ることができる。
また生石灰の反応遅延剤、促進剤、あるいは減水
剤または増粘剤等の慣用の添加剤も使用してさし
つかえない。さらに生石灰微粉が少ないので、本
発明に破壊剤の吸水性のある和紙等に充填しカプ
セル状で使用する場合は紙袋への充填性及び浸水
時の吸水性が良く好適であるが、水と混練してス
ラリー状で使用するときも流し込みに必要な流動
性を得るための水量が少なくてすみ、さらには孔
への密充填性が良いため高膨張圧が得られる。
次に実施例を挙げて本発明を説明する。
実施例１、比較例１、２
実験例１に用いた活性度31.5の生石灰を粉砕
し、ブレーン値1200cm2／ｇの細粒生石灰を作製
し、この細粒80重量部に普通ポルトランドセメン
ト20重量部および減水剤（マイテイ−100、花王
石けん社製）１重量部を加えて混合し破壊剤を調
製した。
破壊剤を20℃恒温室で水比30％で練り混ぜ直径
50cm、高さ50cmの無筋コンクリート試験体（圧縮
強度480Kg／cm2）の中央の充填孔（孔径38mm、
孔長450mm）に注入し噴出の有無と試験体の破砕
時間を測定した。
同様の測定と実施例１に用いた生石灰を粉砕し
ブレーン値3000cm2／ｇにし、実施例１と同様の配
合物に調製したもの（比較例１）についても行な
つた。
更に、コークス炉で焼成された生石灰で、焼き
締めを低くした活性度43のものをブレーン値750
cm2／ｇに粉砕した細粒生石灰を用いて実施例１と
同様の配合物に調製したもの（比較例２）につい
ても同様の測定を行つた。
その結果を第２表に示す。[Table] The expansion pressure measurement test was carried out in a room with an operating environment temperature of 10°C as follows. The destroying agent was filled into a Japanese paper bag (30φ x 250Lmm), shaped into a capsule, immersed in water to absorb water, and then tightly packed into a steel tube for expansion pressure measurement using a filling rod. The relationship between the destructive agent ~ and the expansion pressure 12 hours after the close packing was obtained as shown in the figure. As a result, it was found that the maximum expansion pressure was obtained when fine-grained quicklime with a Blaine value of approximately 1200 cm 2 /g was used, which was previously considered to be inappropriate for use as a crushing agent. Ta. Experimental Example 2 Relationship between the fineness of quicklime and the upper limit temperature for application of a destructive agent containing it The following test was conducted in a room with an operating environment temperature of 30 to 45°C. A capsule of the destructive agent prepared in the same manner as in Experimental Example 1 was placed in a hole (38φ) provided in the concrete specimen.
mm). The highest temperature at which no eruption occurred among the operating environmental temperatures tested for each destructive agent is shown in the figure as the applicable upper limit temperature. As a result, it was found that the lower the Blaine value of the fine quicklime used to prepare the destructive agent, the higher the upper limit temperature for application. This is thought to be due to the fact that the coarser the particle size of quicklime, the more the hydration reaction is suppressed, and the creation of gaps that allow steam generated by the heat of the hydration reaction to easily escape out of the pores. From the above experimental examples 1 and 2, it can be seen that the Blaine value of quicklime suitable as a destructive agent is in a range where the particles are coarser than what was conventionally thought. In other words, the gist of the present invention is that quicklime with a Blaine value of 800 to 800, which is obtained by crushing or classifying quicklime with an activity of 20 to 40.
A destructive agent for brittle objects containing 30% by weight or more of 2000 cm 2 /g fine quicklime. The quicklime used in the present invention has an activity of 20 to 40. For example, quicklime and dolomite are each used individually.
Examples include those obtained by firing at 1300 to 1600°C, and those obtained by adding other substances such as silica and iron to each of these and firing. Activity level is 40
If it exceeds this, it is easy to cause an eruption phenomenon, and the activity level also decreases.
If it is less than 20, high inflation pressure cannot be obtained early. The activity mentioned here is 150% higher than that of the crushed sample.
~300μm 50g, 150μm or less 50g
After separating and mixing, store at 20℃ in a constant temperature room at 20℃.
The slurry was placed in a container containing 400 ml of water (vacuum bottle according to JIS R5203 "Method for measuring heat of hydration of cement") and stirred continuously, and after 10 minutes, the slurry temperature (Celsius) was measured and expressed as an anonymous number. It is. The fine-grained quicklime used in the destructive agent of the present invention needs to have a Blaine value of 800 to 2000cm 2 /g, but in order to quickly obtain a high expansion pressure, it is necessary to
It is desirable to set it to at least cm 2 /g and less than 1500 cm 2 /g. If the Blaine value exceeds 2000 cm 2 /g, the upper limit temperature to which the destructive agent can be applied will be lower, and the resulting early expansion pressure will be lower. Further, if the Blaine value is less than 800 cm 2 /g, it is difficult to obtain a high expansion pressure at an early stage, and when the destructuring agent and water are kneaded and used in the form of a slurry, particles tend to settle, which is not preferable. In order to bring the Blaine value of the fine-grained quicklime used as a crushing agent into a preferable range, it is sometimes possible to crush the hard-burned quicklime with a crusher such as a rod mill, but it is generally preferable to crush the crushed quicklime with an appropriate classifier. Obtained by collecting a range of Blaine values. It is necessary that this fine-grained quicklime be contained in the crushing agent in an amount of 30% by weight or more; if it is less than 30% by weight, the obtained expansion pressure is low and it is not practical. Furthermore, if the amount of fine quicklime is too large, it may erupt when the operating environment temperature is high, so in that case, it is necessary to reduce the amount appropriately. In addition, hydraulic substances such as Portland cement or inorganic powders such as blast furnace slag, fly ash, limestone powder, and silica powder are blended as fillers in the destructive agent of the present invention, but the amount thereof must be 70% by weight or less. There is. Since the destructive agent of the present invention has a small amount of quicklime fine powder with high reaction activity, it is difficult to cause an eruption phenomenon. Therefore, the quicklime content can be relatively increased depending on the usage environment temperature, and high expansion pressure can be obtained quickly. can.
Conventional additives such as quicklime reaction retarders, accelerators, or water reducers or thickeners may also be used. Furthermore, since the amount of quicklime fine powder is small, if the destroying agent of the present invention is used in the form of a capsule by filling it with water-absorbing Japanese paper, it is suitable because it has good filling properties into paper bags and absorbs water when immersed in water. Even when used in the form of a slurry, the amount of water needed to obtain the fluidity required for pouring is small, and furthermore, the pores can be tightly filled, so a high expansion pressure can be obtained. Next, the present invention will be explained with reference to Examples. Example 1, Comparative Examples 1 and 2 The quicklime with an activity of 31.5 used in Experimental Example 1 was crushed to produce fine quicklime with a Blaine value of 1200 cm 2 /g, and 80 parts by weight of the fine particles were mixed with 20 parts by weight of ordinary Portland cement. 1 part by weight and 1 part by weight of a water reducing agent (Mighty-100, manufactured by Kao Soap Co., Ltd.) were added and mixed to prepare a destructive agent. Mix the destructive agent with a water ratio of 30% in a constant temperature room at 20℃.
A filling hole (hole diameter 38 mm ,
The presence or absence of ejection and the crushing time of the specimen were measured. Similar measurements were also carried out on the quicklime used in Example 1 which was pulverized to a Blaine value of 3000 cm 2 /g and prepared into the same formulation as in Example 1 (Comparative Example 1). In addition, quicklime calcined in a coke oven with an activity level of 43 and a low calcination rate has a Blaine value of 750.
Similar measurements were also carried out on a formulation similar to that of Example 1 (Comparative Example 2) prepared using fine quicklime pulverized to cm 2 /g. The results are shown in Table 2.
【表】
本発明の破壊剤は噴出現象もなく適正な時間で
破砕することがわかる。[Table] It can be seen that the crushing agent of the present invention crushes in an appropriate time without any gushing phenomenon.
【図面の簡単な説明】[Brief explanation of the drawing]
図は生石灰の紛末度とこれを含有する破壊剤の
膨張圧および適用上限温度との関係を示すグラフ
である。
The figure is a graph showing the relationship between the fineness of quicklime and the expansion pressure and upper limit temperature of the crushing agent containing it.