JP2997067B2 - Ultra-fast mortar for dry spraying - Google Patents
Ultra-fast mortar for dry sprayingInfo
- Publication number
- JP2997067B2 JP2997067B2 JP40990690A JP40990690A JP2997067B2 JP 2997067 B2 JP2997067 B2 JP 2997067B2 JP 40990690 A JP40990690 A JP 40990690A JP 40990690 A JP40990690 A JP 40990690A JP 2997067 B2 JP2997067 B2 JP 2997067B2
- Authority
- JP
- Japan
- Prior art keywords
- mortar
- silica
- spraying
- ultra
- dry
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Curing Cements, Concrete, And Artificial Stone (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、打継目付着性状及び初
期材令における鋼繊維との付着性状に優れた超速硬モル
タル、また前記性状に加え、更に吹付け施工時の発生粉
塵濃度及びはね返り率の低減効果にも優れた超速硬モル
タルに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a super-fast-hardening mortar which is excellent in adhesion property at seam joints and adhesion property to steel fibers at an early age, and in addition to the above-mentioned properties, furthermore, dust concentration and rebound generated during spraying. The present invention relates to a super-hard mortar having an excellent effect of reducing the rate.
【０００２】[0002]
【従来の技術】近年各種要因によるコンクリート構造物
の劣化に対する対策として、各種の補修、補強工法が提
案されている。これらの１つとして、初期強度発現性を
最大の特徴とする特殊セメントである超速硬セメントを
用いた鋼繊維補強モルタルの乾式吹付け工法が知られて
いる。この工法は、超速硬セメントの初期強度発現性と
吹付け工法の施工性、更に鋼繊維の混入による補強効果
を兼ね備えた工法であり、鉄道高架橋等の断面復旧工法
として利用されている。しかしながら、この様な施工条
件下では、列車通過時の振動が施工上大きな問題となり
易く、新旧コンクリートの打継目付着強度が補修工事の
成否の鍵を握る重要な要因となる。また、これらの補修
工事においては、新コンクリート中に分散混入される補
強用短繊維（鋼繊維等）と、新コンクリートとの付着特
性を確保することも重要である。従って、前記補修工事
等に用いることのできる、打継目付着性状及び鋼繊維等
との付着性状に優れた超速硬モルタル材料の開発が望ま
れていた。2. Description of the Related Art In recent years, various repair and reinforcement methods have been proposed as measures against deterioration of concrete structures due to various factors. As one of these, a dry spraying method of a steel fiber reinforced mortar using a super-rapid hardening cement, which is a special cement having the greatest characteristic of initial strength development, is known. This construction method combines the initial strength development of ultra-rapid hardening cement, the workability of the spray construction method, and the reinforcing effect by mixing steel fibers, and is used as a cross-section restoration method for railway viaducts and the like. However, under such construction conditions, vibrations when passing through the train tend to be a serious problem in construction, and the bond strength of the joints between new and old concrete is an important factor that holds the key to the success of repair work. In these repair works, it is also important to secure adhesion properties between the reinforcing concrete short fibers (such as steel fibers) dispersed in the new concrete and the new concrete. Therefore, there has been a demand for the development of a super-fast-hardening mortar material which can be used for the above-mentioned repair work and has excellent adhesion properties to seams and adhesion properties to steel fibers and the like.
【０００３】一方、非晶質の超微粉であるシリカフュー
ムを吹付け材料に混入すると、吹付け材料の性状、即
ち、施工性、耐水性、耐酸性、耐薬品性、各種強度等が
改善されることが知られている。[0003] On the other hand, when the incorporation of silica full-menu <br/> beam is amorphous ultrafine the spraying material, the properties of spraying material, i.e., workability, water resistance, acid resistance, chemical resistance, It is known that various strengths are improved.
【０００４】また、従来より、湿式吹付け工法において
は、吹付け材料中にシリカフュームを混入すると、吹付
け施工時の発生粉塵量及び吹付け材料のはね返り量を低
減できるが、乾式吹付け工法においては、練り混ぜ水の
添加から吹付け施工迄の練り混ぜ時間が短く、シリカフ
ュームの均質な分散が図れないこと等から、シリカフュ
ームを使用しても、吹付け施工時の発生粉塵量及びはね
返り量の低減効果は、湿式工法ほどには期待できないも
のとされている。前記超速硬モルタルを用いる鉄道高架
橋等の断面復旧工法では、超速硬セメントが接水直後か
ら水和反応を開始するため、湿式工法の採用は不可能で
あり、乾式工法が採用されており、そのため吹付け施工
時の発生粉塵量及び吹付け材料のはね返り量の低減が大
きな課題となっていた。従って、前記補修工事等に用い
ることのできる、前記性状に加え、更に乾式吹付け施工
時の発生粉塵濃度及びはね返り率の低減効果にも優れた
超速硬モルタル材料の開発が望まれていた。[0004] Conventionally, in the wet spraying method, when mixed with silica full volume during spraying material, can be reduced bounce amount of generated dust amount and spraying material during spraying construction, dry spray in method, short mixing time until spray construction from the addition of the kneading water, since such that can not be ensured homogeneous dispersion of the silica off <br/> volume, using silica full Interview <br/> over arm However, the effect of reducing the amount of dust generated during spraying and the amount of rebound is not expected to be as high as that of the wet method. In the cross-section restoration method such as railway viaduct using the ultra-rapid hardening mortar, because the ultra-rapid cement starts the hydration reaction immediately after contact with water, it is impossible to use a wet method, and a dry method is used. Reduction of the amount of dust generated during spraying and the amount of rebound of sprayed material has been a major issue. Therefore, in addition to the above properties, which can be used for the repair work, etc., further dry spraying
It has been desired to develop a super-fast-hardening mortar material which is also excellent in reducing the concentration of dust generated at the time and the rebound rate.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、打継目付着
性状及び初期材令における鋼繊維との付着性状に優れ、
かつ、吹付け施工時の発生粉塵濃度及びはね返り率の低
減効果にも優れた、超速硬セメントの一部をシリカフュ
ームで置換するとともに鋼繊維で補強した乾式吹付け用
超速硬モルタルを提供することを目的とする。DISCLOSURE OF THE INVENTION The present invention has excellent adhesion properties at the seam joint and excellent adhesion properties with steel fibers in the initial age.
It is also an object of the present invention to provide a super-hard mortar for dry spraying, which has an excellent effect of reducing the dust concentration and rebound rate at the time of spraying construction, in which a part of the super-hard cement is replaced with silica fume and reinforced with steel fiber. Aim.
【０００６】[0006]
【０００７】[0007]
【課題を解決するための手段】本発明者等は通常の超速
硬セメントの一部を、特定の割合でシリカフュームで置
換した混合物を用いれば、新旧コンクリートの打継目付
着性状及び補強用短繊維（鋼繊維等）との付着性状を大
きく改善することができることを見出した。すなわち、
超速硬セメント８８〜９２重量％及びシリカフューム８
〜１２重量％からなる混合物、表面水率４〜６％の細骨
材並びに鋼繊維からなる配合のドライモルタルと、吹付
けノズルで乾式吹付けする際に添加する水とからなるこ
とを特徴とする。Means for Solving the Problems The inventors of the present invention have found that if a mixture of a part of ordinary ultra-fast hardening cement and silica fume is used in a specific ratio, the joint adhesion property of old and new concrete and short fibers for reinforcement ( (E.g., steel fiber). That is,
88-92% by weight of ultra-fast hardening cement and silica fume 8
A dry mortar comprising a mixture of １２12% by weight, fine aggregate having a surface water content of 4 to 6% and steel fiber, and water to be added when dry spraying with a spray nozzle. I do.
【０００８】さらに、特定の割合で超速硬セメントの一
部をシリカフュームで置換した混合物を用いた超速硬モ
ルタルの乾式工法による吹付け施工性に関して種々研究
を続けた結果、特定の表面水率を有する細骨材を用いた
ドライモルタルに吹付けノズルで水を混練させれば、モ
ルタル吹付け施工時の発生粉塵濃度及びはね返り率を著
しく低減させることができることを見出した。すなわ
ち、超速硬セメント８８〜９２重量％及びシリカフュー
ム８〜１２重量％からなる混合物、表面水率４〜６％の
細骨材並びに鋼繊維からなる配合のドライモルタルと、
吹付けノズルで乾式吹付けする際に添加する水とからな
る乾式吹付け用超速硬モルタルは、前記の打継目付着性
状及び初期材令における鋼繊維との付着性状に優れ、し
かもモルタル吹付け施工時の発生粉塵濃度およびはね返
り率の低減効果にも優れている。Further, as a result of continuing research on spraying workability of a super-hardening mortar using a mixture in which a part of the super-hardening cement is replaced with silica fume at a specific ratio by a dry method, it has been found that the mortar has a specific surface water content. It has been found that if water is kneaded with a spray nozzle to dry mortar using fine aggregate, the generated dust concentration and rebound rate during mortar spraying can be significantly reduced. That is, a dry mortar having a mixture of 88 to 92% by weight of ultra-rapid hardening cement and 8 to 12% by weight of silica fume, a fine aggregate having a surface water content of 4 to 6%, and a steel fiber;
The ultra-hard mortar for dry spraying comprising water added when dry spraying with a spray nozzle is excellent in the above-mentioned seam adhesion properties and the adhesion properties with steel fibers in the initial age, and furthermore, mortar spraying It is also excellent in reducing the concentration of dust generated at the time and the rebound rate.
【０００９】一般に新旧コンクリートの打継目付着強度
は、旧コンクリート表面の物理的な形状、旧コンクリー
ト表面への付着物の有無、新旧コンクリート間の水分移
動等に大きく影響される。しかしながら、これらの影響
因子が同一である場合には、新旧コンクリート界面の付
着強度は、新コンクリート硬化体の接着強さに支配され
ることになる。超速硬セメント硬化体は、水和反応の初
期において針状の水和生成物であるエトリンガイトを生
成することが知られている。本発明において超速硬セメ
ント中に混入されたシリカフュームは、この針状の結晶
構造の空隙部を充填し、この結果、超速硬セメント硬化
体と被接着物、即ち、旧コンクリート面と新コンクリー
ト中の水和反応部との物理的な接着而積が増加すること
となり、その結果新旧コンクリート界面の接着強度が改
善される。Generally, the joint strength between new and old concrete is greatly affected by the physical shape of the old concrete surface, the presence or absence of extraneous matter on the old concrete surface, and the movement of moisture between the old and new concrete. However, when these influencing factors are the same, the bond strength at the interface between the old and new concretes is governed by the bond strength of the hardened new concrete body. Ultra rapid-cured cement is to generate Etoringa wells acicular hydrated product at the beginning of the hydration reaction is known. Silica full volume mixed in ultra rapid setting cement in the present invention fills the gap portion of the needle-like crystal structure, as a result, super rapid cement hardened body and adherend, i.e., the old concrete surface and new concrete The physical bond capacity with the hydration reaction part in the inside is increased, and as a result, the bond strength at the interface between the old and new concrete is improved.
【００１０】また補強用短繊維（鋼繊維等）とモルタル
又はコンクリートとの付着強度は、繊維表面の親水性、
モルタル又はコンクリートの強度、繊維表面の形状、繊
維表面に付着した異物の有無等に影響される。本発明の
シリカフュームを混入した超速硬セメントを用いたモル
タル又はコンクリートは、通常の超速硬セメントを用い
たモルタル又はコンクリートと比して、微視的なブリー
ジングが発生しないため、モルタル又はコンクリート中
に分散配置された補強用短繊維（鋼繊維等）の全周にわ
たり、良好な付着性を確保できる。また超速硬セメント
水和物であるエトリンガイトの針状結晶の空隙部を、シ
リカフュームが充填し、より緻密なモルタル又はコンク
リートを形成するため、補強用短繊維（鋼繊維等）とモ
ルタル又はコンクリートとの物理的な付着性状が改善さ
れ、その結果、モルタル又はコンクリートと補強用短繊
維（鋼繊維等）との付着性状が改善される。The bonding strength between reinforcing short fibers (such as steel fibers) and mortar or concrete is determined by the hydrophilicity of the fiber surface,
It is affected by the strength of the mortar or concrete, the shape of the fiber surface, the presence or absence of foreign matter attached to the fiber surface, and the like. For mortar or concrete using ultrafast cement obtained by mixing <br/> silica full volume of the present invention, which compared with the mortar or concrete using the conventional ultra-rapid setting cement, microscopic breathing does not occur, Good adhesion can be secured over the entire circumference of the reinforcing short fibers (such as steel fibers) dispersed in mortar or concrete. The voids of the needle-like crystals of Etoringai bets are ultrafast cement hydrates, shea <br/> silica off volume is filled, to form a denser mortar or concrete, the short fibers (steel fibers for reinforcing Etc.) and the mortar or concrete are physically improved, and as a result, the adhesion between the mortar or concrete and the reinforcing short fibers (such as steel fibers) is improved.
【００１１】一般に、高炉スラグ微粉末、フライアッシ
ュ等のポゾラン物質で超速硬セメントの一部を置換した
場合には、ポゾラン反応に起因する各種性状の改善効果
が期待できる。このことは、本発明のように粉末度が高
く、水和活性度の非常に高いシリカフュームを混和材と
して用いる場合にも、例外ではない。従って、前記付着
性状の改善を目的として、超速硬セメントの一部をシリ
カフュームで置換する本発明においては、前記の通り、
超速硬セメント８８〜９２重量％に対してシリカフュー
ム８〜１２重量％程度の割合で置換することが好まし
く、この程度の混合割合の場合には、超速硬セメントの
初期強度発現性を損なうことなく、前記付着性状が改善
される。In general, when a part of ultra-fast hardening cement is replaced by a pozzolanic substance such as blast furnace slag fine powder or fly ash, the effect of improving various properties caused by the pozzolanic reaction is improved.
Can be expected. This high fineness as in the present invention, even when using a very high silica off volume of hydration activity as admixture, no exception. Therefore, for the purpose of improving the adhesion properties, in the present invention to substitute a portion of the ultra-rapid-cement silica <br/> excitation volumes, the street,
Preferably be replaced at a rate of silica full-menu <br/> arm about 8-12% by weight relative to the ultra-rapid setting cement 88-92% by weight, in the case of the mixing ratio of this degree, initial strength of ultrafast cement The adhesion properties are improved without impairing the expression.
【００１２】シリカフュームは、シリコンメタル、フェ
ロシリコン生産時の排気ガス中に含まれるマイクロシリ
カ粒子で、バグフィルターにより捕収された平均粒径
０．１５μｍ程度の超微粒子で、通常９０％程度以上の
ＳｉＯ２を含有している。市販のシリカフュームには、
微粒子状のもの、比表面積２０００ｃｍ２／ｇ程度に凝
集加工したもの、液体中に懸濁し、スラリー化したもの
等があるが、本発明においてはいずれのシリカフューム
を用いてもよい。本発明に用いられるシリカフュームと
しては、ＳｉＯ２含量９０％以上で、平均粒径約０．１
５μｍ、比表面積１５〜２５万ｃｍ２／ｇ程度のものが
好ましい。[0012] Silica off volume is silicon metal, micro silica particles contained in the exhaust gas during ferrosilicon production, ultrafine particles having an average particle size of about 0.15μm, which is ToOsamu by bag filter, usually about 90% It contains the above SiO 2 . The commercially available silica full volume,
Those particulate, those aggregated processed into about a specific surface area of 2000 cm 2 / g, suspended in a liquid, there are such that slurried, may be any of silica full volume in the present invention. The silica full volume to be used in the present invention, in SiO 2 content of 90% or more, average particle size of about 0.1
Those having a thickness of about 5 μm and a specific surface area of about 150,000 to 250,000 cm 2 / g are preferred.
【００１３】また、通常の超速硬セメント８８〜９２重
量％およびシリカフューム８〜１２重量％からなる混合
物を用い、しかも表面水率４〜６％の細骨材を使用して
得られる超速硬モルタルは、乾式工法により吹付け施工
した場合、吹付け施工時の発生粉塵濃度およびはね返り
率をかなり低減させることができる。この際、表面水率
４〜６％程度の細骨材を使用し、ドライモルタル練り混
ぜ時にシリカフュームを細骨材及び超速硬セメントと事
前に混合する。これはシリカフュームの均質な分散を図
ると共に、シリカフュームと細骨材の有する適度な表面
水とを反応させてシリカフュームに所定の粘稠性を発現
させるためである。この結果、吹付け施工時の発生粉塵
濃度は、シリカフュームの混入により４０〜５０％程度
低減し、同時に吹付け材料のはね返り率も減少する。細
骨材の表面水率が、少なすぎる場合には、シリカフュー
ムの混入による粉塵濃度の低減効果が損なわれ、また多
過ぎる場合には、乾式吹付け時の圧送ホースの閉鎖が頻
発することとなる。[0013] The ultra-rapid hardening mortar obtained by using a mixture of 88 to 92% by weight of ordinary ultra-rapid hardening cement and 8 to 12% by weight of silica fume and using fine aggregate having a surface water content of 4 to 6% is In the case of spraying by the dry method, the concentration of dust generated during the spraying and the rebound rate can be considerably reduced. At this time, fine aggregate having a surface water content of about 4 to 6% is used, and silica fume is mixed in advance with the fine aggregate and the ultra-rapid hardening cement during kneading with dry mortar. This is to promote uniform dispersion of the silica fume and to cause silica fume to exhibit a predetermined viscosity by reacting the silica fume with an appropriate surface water of the fine aggregate. As a result, the dust concentration generated during spraying is reduced by about 40 to 50% due to the mixing of silica fume, and at the same time, the rebound rate of the sprayed material is reduced. If the surface water content of the fine aggregate is too small, the effect of reducing the dust concentration due to the mixing of silica fume is impaired, and if it is too large, the closing of the pressure-feeding hose during dry spraying frequently occurs. .
【００１４】この吹付け施工時の発生粉塵濃度及びはね
返り率を低減させた、本発明の超速硬モルタルにおいて
も、使用されるシリカフュームは、前述の通りであり、
市販のシリカフュームのいずれをも用いることができ、
ドライモルタル練り混ぜ時に細骨材及び超速硬セメント
と混合可能であればよい。[0014] The generating dust concentration and rebound rate during the spray construction has been reduced, even in the ultra-fast curing mortar of the present invention, silica full volume used is as defined above,
Can also be used any commercially available silica off volume,
Any material that can be mixed with the fine aggregate and the ultra-rapid hardening cement at the time of mixing with the dry mortar may be used.
【００１５】吹付けモルタルの標準的な配合は、単位結
合材量３５０〜６００ｋｇ／ｍ３、単位水量１００〜３
００ｋｇ／ｍ３、繊維混人率０．５〜４体積％程度であ
る。The standard composition of the spray mortar is as follows : unit binder amount 350-600 kg / m 3 , unit water amount 100-3
00 kg / m 3 , and a fiber mixture rate of about 0.5 to 4% by volume.
【００１６】[0016]
【実施例】実施例１ シリカフュームを混入した超速硬モルタル又はコンクリ
ートと補強用鋼繊維との付着性状について検討した。表
１に使用材料及びシリカフュームの分析結果を示す。用
いた練り混ぜモルタルの水結合材比は４５％、砂結合材
比は１．５、細骨材は豊浦標準砂とし、更に高性能減水
剤及び擬結遅延剤をそれぞれ結合材重量の２％、０．３
％使用した。付着試験はＪＣＩ−ＳＦ８「繊維の付着試
験方法」に準じ、試験材令３時間から適時実施した。EXAMPLES was examined bond behavior between ultra rapid-mortar or concrete mixed with Example 1 Silica full volume and the reinforcing steel fibers. Using Table 1 shows the materials and analysis of the silica off volume. The ratio of the water binder in the kneading mortar used was 45%, the ratio of the sand binder was 1.5, the fine aggregate was Toyoura standard sand, and the high-performance water reducing agent and the pseudo-setting retarder were each 2% of the weight of the binder. , 0.3
%used. The adhesion test was carried out as appropriate according to JCI-SF8 “Fiber adhesion test method” from 3 hours of test material.
【００１７】[0017]
【表１】 [Table 1]
【００１８】図１に鋼繊維の付着強度と材令の関係を示
す。図１より、鋼繊維とモルタルとの付着強度は、特に
初期材令において、改善されている。シリカフューム未
混入の場合でも、超速硬セメントを用いたモルタルと鋼
繊維との付着性状は、普通セメントを用いた場合と比較
して、比較的良好であることと、今回のこの試験結果を
合わせて考えると、鋼繊維と、シリカフュームを用いる
モルタルとの付着特性を有効に利用するためには、より
高強度の鋼繊維を使用することが重要である。FIG. 1 shows the relationship between the bonding strength of steel fibers and the material age. FIG. 1 shows that the bond strength between the steel fiber and the mortar is improved, especially in the early age. Even in the case of silica full volume Not mixed, bond behavior between mortar and steel fibers with the ultra-rapid-cement, as compared with the case of using the ordinary cement, and it is relatively good, the test results of this Taken together, and steel fibers, in order to effectively utilize the adhesive properties of the mortar using silica full volume, it is important to use a higher-strength steel fibers.
【００１９】なお、この時の圧縮強度は、図２にモルタ
ルの圧縮強度と材令との関係を示すように、いずれも材
令に伴い増加している。しかしながらその傾向は、シリ
カフューム置換率の影響を受け、特に置換率２０％の場
合、材令６時間〜７日における圧縮強度は、置換率０％
と比して明らかに低下している。このことよりシリカフ
ユームの置換率が適切（８〜１２％）であれば、その初
期強度発現性は損なわれないことが明らかである。The compressive strength at this time increases with the material age, as shown in FIG. 2 showing the relationship between the compressive strength of the mortar and the material age. However this tendency is influenced by silica <br/> excitation volume replacement rate, especially in the case of substitution of 20%, the compressive strength of wood age 6 hours to 7 days, substitution of 0%
It is clearly lower than that. If the substitution rate of the silica off <br/> Yumu than this it is appropriate (8% to 12%), its initial strength development is clear that not impaired.
【００２０】実施例２ 超速硬吹付けモルタルを用いて、コンクリートパネルと
吹付けモルタルとの打継目付着性状について検討した。
表２に吹付け実験時のモルタル配合例を示す。今回の試
験では、砂結合材比を４（一定）、シリカフューム置換
率を１０％とした。また、水結合材比は４５％とした。
なお超速硬吹付けモルタルの水結合材比は、図３に示す
吹付けシステムの練り混ぜ水の圧送管中に配置した瞬間
流量計により測定した練り混ぜ水量、ドライモルタル配
合及び単位時間当たりの材料吐出量より算出した。シリ
カフュームとしては比表面積２０００ｃｍ ２ ／ｇ程度に
凝集加工したものを用いた。 Example 2 Using a super-hard blasting mortar, the seam adhesion between the concrete panel and the blasting mortar was examined.
Table 2 shows examples of the mortar composition at the time of the spraying test. In this test, a sand binder ratio 4 (constant), and the silica full volume replacement ratio was 10%. The water binder ratio was 45%.
The water binder ratio of the super-hard blasting mortar was determined by the amount of mixing water, the dry mortar composition, and the material per unit time measured by an instantaneous flow meter placed in the pumping pipe of the mixing water of the spraying system shown in FIG. It was calculated from the discharge amount. Siri
The specific surface area of 2,000 cm 2 / g
Agglomeration processing was used.
【００２１】[0021]
【表２】 [Table 2]
【００２２】図４に打継目付着強度試験の手順を示す。
打継面である旧コンクリート表面はグリッド径０．５ｍ
ｍのブラスト機を用い、０．４ｍｍ程度の深さにブラス
ト処理した。試験は材令７日及び２８日で実施した。吹
付け後のパネルは、屋外にて湿潤状態で保管し、コア供
試体は試験３日前に採取した。FIG. 4 shows the procedure of the joint strength test.
The old concrete surface which is the joint surface is grid diameter 0.5m
The blast processing was performed to a depth of about 0.4 mm using a blast machine of m. The test was performed on the 7th and 28th days of the material age. The panel after spraying was stored outdoors in a wet state, and the core specimen was collected three days before the test.
【００２３】図５に打継目付着強度試験結果を示す。図
５より、置換率１０％の打継目付着強度は、材令７日及
び２８日共に置換率０％の強度を上回っている。この結
果より、超速硬吹付けモルタルの打継目付着強度は、シ
リカフュームの使用により、かなり改善できることが明
らかである。FIG. 5 shows the results of the seam adhesion strength test. As shown in FIG. 5, the bond strength at the joint at the replacement rate of 10% exceeds the strength at the replacement rate of 0% on both the 7th and 28th days. From this result, droplet seam adhesion strength ultra rapid-spray mortar, the use of shea <br/> silica off volume, it is clear that it is possible to considerably improve.
【００２４】なお、本発明のシリカフュームで置換した
超速硬セメントを用いた吹付けモルタル中のシリカフュ
ーム粒子を示す電子顕微鏡写真によると、塊状のシリカ
フューム粒子は完全に分散していないものの、その周囲
には細かな球状粒子が認められ、シリカフューム粒子に
より、セメント水和物の空隙が充填されている状況が観
察できた。[0024] Incidentally, according to silica off Interview <br/> electron micrograph showing the over-time particle spraying mortar with ultrafast cement was replaced with silica full volume of the present invention, bulk silica
Although full volume particles are not completely dispersed fine spherical particles were observed on the periphery thereof, with silica off volume particles, a situation where voids of the cement hydrate is filled could be observed.
【００２５】実施例３ シリカフユームの有無（置換率０及び１０％）及び細骨
材の表面水率（２、４、６％）が発生粉塵濃度及び吹付
け材料のはね返り率に及ぼす影響について検討した。表
３に使用材料、シリカフユームの化学分析結果及び目標
吐出配合を示す。 [0025] Effect of the rebound rate of Example 3 presence of silica off Yumu (substitution rate 0 and 10%) and surface water ratio of fine aggregate (2, 4, 6%) occurs dust concentration and spraying material investigated. table
3. Materials used, results of chemical analysis of silica fume and targets
Shows the ejection mix.
【００２６】[0026]
【表３】 [Table 3]
【００２７】実験は、図３に示す吹付けシステムを用
い、８×６×３ｍのテント内に鉛直に設置した１×２ｍ
のパネルに、超速硬モルタルを約２０ｃｍの厚さで水平
方向から吹付け、そのときの粉塵濃度及びはね返り率を
測定した。粉塵濃度の測定には、７．０７μｍ以上の粗
大粒子を除去するためのセパレーターを有するローボリ
ュームサンプラーにより、質量濃度換算係数を校正した
光量積算型デジタル粉塵計を用いた。測定は吹付け位置
から３、５、７ｍ後方、高さ１．５ｍで実施した。また
はね返り率は吹付け前後のパネル重量及び吹付け施工後
に回収したリバウンド重量より算出した。図３中、１は
材料ヤード、２は強制ミキサー、３はベルトコンベヤ
ー、４は水タンク、５はコンプレッサー、６は吹付け
機、７は水ポンプ、８は瞬間流量計、９は吹付けノズル
を示す。また圧送距離は約３０ｍ、圧送管の管径は１．
５インチである。The experiment was performed using the spraying system shown in FIG. 3 and a 1 × 2 m vertically set in an 8 × 6 × 3 m tent.
Was sprayed from a horizontal direction with a thickness of about 20 cm to the panel, and the dust concentration and rebound rate at that time were measured. In the measurement of the dust concentration, the mass concentration conversion coefficient was calibrated by a low volume sampler having a separator for removing coarse particles of 7.07 μm or more.
A light- integrated digital dust meter was used. The measurement was carried out at a height of 1.5 m, 3 , 5 , 7 m behind the spray position. Alternatively, the rebound rate was calculated from the panel weight before and after spraying and the rebound weight collected after spraying. In FIG. 3, 1 is a material yard, 2 is a forced mixer, 3 is a belt conveyor, 4 is a water tank, 5 is a compressor, 6 is a spray machine, 7 is a water pump, 8 is an instantaneous flow meter, 9 is a spray nozzle. Is shown. The pumping distance is about 30m and the diameter of the pumping tube is 1.
5 inches.
【００２８】図６に超速硬モルタル吹付け時の平均粉塵
濃度と細骨材の表面水率との関係を示す。図６より、表
面水率が２％の場合はシリカフュームの有無に係わらず
粉塵濃度はほぼ同等であるが、表面水率が４又は６％と
なるとシリカフュームの使用により粉塵濃度は明らかに
低下している。このことから、乾式吹付け工法において
も細骨材の表面水を適宜管理すれば、シリカフュームを
用いて粉塵濃度を低下させることが可能であることが判
明した。FIG. 6 shows the relationship between the average dust concentration at the time of spraying the ultra-fast mortar and the surface water content of the fine aggregate. From FIG. 6, but if the surface water ratio is 2% dust concentration or without silica full volume is almost equivalent, dust concentration by the use of silica off volume if the surface water ratio is 4 or 6% clear Has declined. Therefore, if properly manage the surface water of fine aggregate also in the dry spraying method, it is possible to reduce the dust concentration was found using silica full volume.
【００２９】乾式吹付け工法においては、細骨材の表面
水率は施工能率に影響するため、粉塵濃度のみから使用
細骨材の表面水率を規定することはできない。図７に超
速硬吹付けモルタルの時間当たり吐出量と細骨材の表面
水率の関係を示す。図７より、シリカフュームの有無に
係わらず表面水率が４％の時、吐出量は最大となってお
り、またシリカフュームを使用した場合には、表面水率
が４％から６％に増加しても吐出量に及ぼす影響は小さ
い。従って、今回の材料において施工能率から決定され
る細骨材の最適表面水率は４〜６％程度であると考えら
れる。これは粉塵濃度から決定する値に近く、実用範囲
内では粉塵濃度を元に表面水率を管理しても、施工能率
上の問題は発生しないといえる。In the dry spraying method, since the surface water content of the fine aggregate affects the construction efficiency, the surface water content of the fine aggregate used cannot be specified only from the dust concentration. FIG. 7 shows the relationship between the discharge rate per hour of the ultra-fast spray mortar and the surface water content of the fine aggregate. 7 that when though not surface water ratio of the presence of the silica-off volume is 4%, the discharge amount is a maximum, and when using a silica-off volume, the surface water ratio is 6% 4% The effect on the ejection amount is small even if the number increases. Therefore, it is considered that the optimal surface water rate of the fine aggregate determined from the construction efficiency in this material is about 4 to 6%. This is close to the value determined from the dust concentration, and it can be said that within the practical range, even if the surface water content is controlled based on the dust concentration, no problem occurs in the construction efficiency.
【００３０】図８に表面水率６％の粉塵濃度の経時変化
を示す（測定位置３ｍ、５ｍ、７ｍ）。図８より、シリ
カフュームの使用により、粉塵濃度は吹付けの全般にお
いて減少している。[0030] shows the time course of the front surface of water of 6% dust concentration in FIG. 8 (measurement position 3m, 5m, 7m). From FIG. 8, the use of silica <br/> excitation volume, dust concentration is reduced in the overall spraying.
【００３１】図９にはね返り率と細骨材の表面水率との
関係を示す。図９より、超速硬吹付けモルタルのはね返
り率はシリカフュームの使用により減少傾向にあるとい
える。なお今回、吹付けは水平方向に実施したが、これ
を高架橋の補修工事等に適用した場合には、鉛直方向へ
の作業が多くなるため、シリカフュームの使用によるは
ね返り率の低減効果はより明らかになるものと思われ
る。[0031] FIG. 9 shows the relationship between the I return rate and fine aggregate surface water rate. 9 that bounce rate of ultra-rapid-spray mortar can be said to be in decline by the use of silica off volume. Note this, although spraying was performed in the horizontal direction, the case of applying this to the repair work or the like of the viaduct, it becomes much work in the vertical direction, the effect of reducing the bounce rate by use of the silica-off volume is more It seems to be clear.
【００３２】本発明の乾式吹付け用超速硬モルタルは、
超速硬セメント８８〜９２重量％及びシリカフューム８
〜１２重量％からなる混合物、表面水率４〜６％の細骨
材並びに鋼繊維からなる配合のドライモルタルと、吹付
けノズルで乾式吹付けする際に添加する水とからなるこ
とから、ドライモルタル練混ぜ時に、シリカフュームを
細骨材および超速硬セメントと事前に混合して、シリカ
フュームの均質な分散を図ると共に、シリカフュームと
細骨材の有する適度な表面水とを反応させてシリカフュ
ームに所定の粘稠性を発現させ、その結果としてモルタ
ル吹付け施工時の発生粉塵濃度およびはね返り率の低減
効果を高めることができる。そして、４〜６％の最適な
表面水率の細骨材が使用されてシリカフュームの均質な
分散が行われるとともにシリカフュームに所定の粘稠性
を発現させることにより、吹付けノズルを用いて乾式吹
付け施工する際にドライモルタルにモルタル又はコンク
リートの水和反応に必要な水を添加すれば、乾式吹付け
時の圧送ホースの閉塞を引き起こすことなく施工するこ
とができ、しかも粉塵濃度およびはね返り率の低減が行
われて、現場施工性を効果的に向上させることができ
る。さらに、吹付け施工時の発生粉塵濃度およびはね返
り率が低減して現場施工性が向上したことにより、鉄道
高架橋等の補修工事のように列車等の通過時の振動の影
響がある鉛直方向への作業が含まれる作業の場合には、
特に作業性が向上し、工期短縮に寄与することができ
る。さらにまた、打継目付着性状及び初期材令における
鋼繊維との付着性状に優れているため各種の補修、補強
工事の用途に適用できる。The super-hard mortar for dry spraying of the present invention comprises:
88-92% by weight of ultra-fast hardening cement and silica fume 8
Dry mortar composed of a mixture of 〜12% by weight, fine aggregate having a surface water content of 4 to 6% and steel fiber, and water to be added when dry spraying with a spray nozzle. At the time of kneading the mortar, the silica fume is mixed in advance with the fine aggregate and the ultra-rapid hardening cement to achieve a uniform dispersion of the silica fume, and at the same time, react the silica fume with an appropriate surface water of the fine aggregate to cause the silica fume to have a predetermined density. The viscous property is developed, and as a result, the effect of reducing the generated dust concentration and the rebound rate at the time of mortar spraying can be enhanced. Then, fine aggregate having an optimum surface water content of 4 to 6% is used to uniformly disperse the silica fume, and the silica fume exhibits a predetermined viscosity. By adding water necessary for the hydration reaction of mortar or concrete to dry mortar during installation, it is possible to perform installation without causing blockage of the pumping hose at the time of dry spraying, and furthermore, dust concentration and rebound rate The reduction is performed, and the on-site workability can be effectively improved. Furthermore, the dust concentration and rebound rate generated during spraying work have been reduced and the workability has been improved, and as a result of vibrations when passing trains, etc. For work that includes work,
In particular, the workability is improved, which can contribute to shortening the construction period. Furthermore, since it is excellent in the adhesion property of the seam joint and the adhesion property with the steel fiber in the initial age, it can be applied to various repair and reinforcement applications.
【図１】鋼繊維の付着強度と材令の関係を示すグラフで
ある。FIG. 1 is a graph showing the relationship between steel fiber adhesion strength and material age.
【図２】モルタルの圧縮強度と材令との関係を示すグラ
フである。FIG. 2 is a graph showing the relationship between compressive strength of mortar and material age.
【図３】吹付けシステムを示す説明図である。FIG. 3 is an explanatory view showing a spraying system.
【図４】打継目付着強度試験の手順を示す説明図であ
る。FIG. 4 is an explanatory view showing a procedure of a seam adhesion strength test.
【図５】打継目付着強度試験結果を示すグラフである。FIG. 5 is a graph showing the results of a seam adhesion strength test.
【図６】粉塵濃度と表面水率との関係を示すグラフであ
る。6 is a graph showing the relationship between a dust density and surface water ratio.
【図７】吐出量と表面水率との関係を示すグラフであ
る。7 is a graph showing the relationship between the discharge amount and surface water ratio.
【図８】粉塵濃度の経時変化を示すグラフである。FIG. 8 is a graph showing the change over time in the dust concentration.
【図９】はね返り率と表面水率との関係を示すグラフで
ある。FIG. 9 is a graph showing a relationship between a rebound rate and a surface water rate .
１ 材料ヤード ２ 強制ミキサー ４ 水タンク ５ コンプレッサー ６ 吹付け機 ９ 吹付けノズル1 material yard 2 positive mixer 4 Water tank 5 compressors 6 blast machine 9 spray nozzle
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平２−311347（ＪＰ，Ａ) 特開 平２−252643（ＪＰ，Ａ) 特開 昭61−215239（ＪＰ，Ａ) 特開 昭61−178461（ＪＰ，Ａ) 特開 昭63−117936（ＪＰ，Ａ) 特開 昭64−42345（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C04B 28/04,22/06 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-311347 (JP, A) JP-A-2-252463 (JP, A) JP-A-61-215239 (JP, A) JP-A-61-215239 178461 (JP, A) JP-A-63-117936 (JP, A) JP-A-64-42345 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C04B 28 / 04,22 / 06
Claims (1)
カフューム８〜１２重量％からなる混合物、表面水率４
〜６％の細骨材並びに鋼繊維からなる配合のドライモル
タルと、吹付けノズルで乾式吹付けする際に添加する水
とからなる乾式吹付け用超速硬モルタル。1. A mixture consisting of 88 to 92% by weight of ultra-fast hardening cement and 8 to 12% by weight of silica fume, having a surface water content of 4
Dry mortar containing up to 6% fine aggregate and steel fiber, and water added when dry spraying with a spray nozzle
A super-hard mortar for dry spraying consisting of:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP40990690A JP2997067B2 (en) | 1990-12-12 | 1990-12-12 | Ultra-fast mortar for dry spraying |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP40990690A JP2997067B2 (en) | 1990-12-12 | 1990-12-12 | Ultra-fast mortar for dry spraying |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11209881A Division JP2000072506A (en) | 1999-07-23 | 1999-07-23 | Dry spraying construction of ultra-quick hardening mortar |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04214055A JPH04214055A (en) | 1992-08-05 |
| JP2997067B2 true JP2997067B2 (en) | 2000-01-11 |
Family
ID=18519159
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP40990690A Expired - Lifetime JP2997067B2 (en) | 1990-12-12 | 1990-12-12 | Ultra-fast mortar for dry spraying |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2997067B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4799729B2 (en) * | 2000-11-14 | 2011-10-26 | 太平洋セメント株式会社 | Metal fibers for reinforcing cementitious hardened bodies |
| KR100467645B1 (en) * | 2002-03-05 | 2005-01-24 | 우경건설 주식회사 | High tension strength concrete and method for constructing double concrete structures using the same |
| JP5154435B2 (en) * | 2006-11-17 | 2013-02-27 | 電気化学工業株式会社 | Cement mortar composition for grout and grout mortar using the same |
-
1990
- 1990-12-12 JP JP40990690A patent/JP2997067B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04214055A (en) | 1992-08-05 |
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