JP2003221264A - Quick setting agent for mortar or concrete - Google Patents
Quick setting agent for mortar or concreteInfo
- Publication number
- JP2003221264A JP2003221264A JP2002019837A JP2002019837A JP2003221264A JP 2003221264 A JP2003221264 A JP 2003221264A JP 2002019837 A JP2002019837 A JP 2002019837A JP 2002019837 A JP2002019837 A JP 2002019837A JP 2003221264 A JP2003221264 A JP 2003221264A
- Authority
- JP
- Japan
- Prior art keywords
- quick
- weight
- mortar
- setting agent
- setting
- 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.)
- Pending
Links
- 239000004570 mortar (masonry) Substances 0.000 title claims abstract description 24
- 239000004567 concrete Substances 0.000 title claims abstract description 16
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 31
- 239000000203 mixture Substances 0.000 claims abstract description 17
- 239000003513 alkali Substances 0.000 claims abstract description 12
- 239000010440 gypsum Substances 0.000 claims abstract description 8
- 229910052602 gypsum Inorganic materials 0.000 claims abstract description 8
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 6
- 150000004645 aluminates Chemical class 0.000 claims abstract description 5
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims abstract description 5
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 3
- 239000000126 substance Substances 0.000 claims abstract description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 9
- 239000004568 cement Substances 0.000 abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 14
- 238000005086 pumping Methods 0.000 abstract description 10
- 229910052782 aluminium Inorganic materials 0.000 abstract description 5
- 150000001875 compounds Chemical class 0.000 abstract description 4
- 230000007774 longterm Effects 0.000 abstract description 3
- 239000011378 shotcrete Substances 0.000 abstract description 2
- 238000007664 blowing Methods 0.000 abstract 1
- 239000011734 sodium Substances 0.000 description 12
- 238000005507 spraying Methods 0.000 description 12
- 239000000463 material Substances 0.000 description 11
- 230000000694 effects Effects 0.000 description 9
- 238000006703 hydration reaction Methods 0.000 description 9
- 230000036571 hydration Effects 0.000 description 7
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- -1 alkali metal aluminates Chemical class 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 239000012071 phase Substances 0.000 description 5
- 230000010349 pulsation Effects 0.000 description 5
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 4
- 238000013329 compounding Methods 0.000 description 4
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 229910001388 sodium aluminate Inorganic materials 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- 235000017550 sodium carbonate Nutrition 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- XFWJKVMFIVXPKK-UHFFFAOYSA-N calcium;oxido(oxo)alumane Chemical compound [Ca+2].[O-][Al]=O.[O-][Al]=O XFWJKVMFIVXPKK-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 235000010755 mineral Nutrition 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 229910017090 AlO 2 Inorganic materials 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910001593 boehmite Inorganic materials 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- ZOMBKNNSYQHRCA-UHFFFAOYSA-J calcium sulfate hemihydrate Chemical compound O.[Ca+2].[Ca+2].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O ZOMBKNNSYQHRCA-UHFFFAOYSA-J 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 239000010431 corundum Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 150000004683 dihydrates Chemical class 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 150000004677 hydrates Chemical class 0.000 description 1
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- KVOIJEARBNBHHP-UHFFFAOYSA-N potassium;oxido(oxo)alumane Chemical compound [K+].[O-][Al]=O KVOIJEARBNBHHP-UHFFFAOYSA-N 0.000 description 1
- 238000000634 powder X-ray diffraction Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、高水比にしても、
高い強度発現性が得られ、吹付け用途に適したモルタル
・コンクリート用急結剤に関する。
【０００２】
【従来の技術】水和活性に優れた混和剤をセメントに混
合すると、セメントの硬化、凝結速度を調整することが
でき、これによりコンクリートやモルタルの初期強度が
著しく高くなり、凝結を極端に短くすることができる。
また、このような性能を有する急結剤を用いると、トン
ネルの天井部、橋台下などの天端にコンクリートやモル
タルを吹付ける、吹付け工法に広く使用することができ
る。昨今では、その簡便さ、施工効率の良さ等から吹付
け工法による工事が増加し、それに連れて、急結剤への
要求性能も一層高いものとなっている。即ち、急結剤に
は、付着性が高く、吹付け時の跳ね返りが少なく、凝結
が早く、付着後極短直ちに硬化し、その後、３時間程度
の短期の強度発現性及び材齢２８日の強度発現性が高い
こと等が要求されている。
【０００３】このような性状を満たす急結剤としては、
アルカリ金属アルミン酸塩を主体とするもの、溶融アル
ミン酸カルシウムを主体とするものなどが知られてい
る。これらの急結剤は、吹付けたモルタルやコンクリー
トにおいて凝集力の大きい水和物を生成し、急結性を付
与させる仕組みになっているが、その際アルカリ成分が
多く用いられるために、その後のセメントの水和反応に
支障を及ぼし、硬化後の長期強度の発現性が急結剤を添
加しない場合よりも著しく低下するような現象が現れる
ので、より高い強度発現性を付与できる高強度タイプの
急結剤が実施工上必要となっている。
【０００４】一方で、前記のような急結剤の急結性能は
セメント混練時の配合水量が多くなる（高水比）に連れ
て低下するため、０．５以下の低水比で使用される。し
かるに水量を低下させると、吹付け施工時の材料のポン
プ圧送の際に、圧送管が閉塞しやすくなり、また圧送材
の高粘化に伴う圧送抵抗と瞬結性が強まるが故に圧送コ
ンクリートの脈動が生じ易く、吹き斑が起こり易いとい
う問題があった。
【０００５】
【発明が解決しようとする課題】従って、本発明は、吹
付け材で使用した場合の吹付け圧送管の閉塞と吹き斑が
発生し難い０．５を超える高水比で使用しても、所望の
急結性能を維持しつつ短期〜中長期に渡って高い強度発
現性を示すことができるモルタル・コンクリート用急結
剤を提供することを課題とする。
【０００６】
【課題を解決するための手段】本発明者等は、前記課題
解決のため検討を行った結果、比較的ＣａＯ含有量の少
ないＣａＯ−Ｎａ2Ｏ−Ａｌ2Ｏ3系組成物を主成分と
し、これに急結性を補完する作用を有するアルカリ総量
を低下させた特定の無機塩類配合物を加えることによ
り、高水比でも優れた急結性状を維持しつつ高い強度発
現性を有する急結剤が得られることを見出し、本発明を
完成するに至った。
【０００７】即ち、本発明は、次の成分（Ａ）〜
（Ｄ）：
（Ａ）１０００〜１４００℃で焼成され、ＣａＯ ２５
〜５０重量％、Ｎａ2Ｏ５〜２３重量％及びＡｌ2Ｏ3
３０〜４８重量％の化学成分を有するＣａＯ−Ｎａ2Ｏ
−Ａｌ2Ｏ3系組成物：１００重量部、
（Ｂ）アルミン酸アルカリ、水酸化アルミニウム及び低
結晶質乃至非晶質の酸化アルミニウムから選ばれる１種
以上：３〜３１重量部、
（Ｃ）炭酸アルカリ：１１〜３３重量部、
（Ｄ）石膏類：５〜８５重量部
を含有するモルタル・コンクリート用急結剤を提供する
ものである。
【０００８】
【発明の実施の形態】本発明のモルタル・コンクリート
用急結剤を構成する成分（Ａ）は、ＣａＯ−Ｎａ2Ｏ−
Ａｌ2Ｏ3系組成物（以下「ＣＮＡ」と称す。）であっ
て、ＣａＯ、Ｎａ2Ｏ及びＡｌ2Ｏ3を特定の配合割合と
した混合物を１０００〜１４００℃で焼成してなる組成
物である。焼成温度が１４００℃を超えるとＮａ2Ｏの
揮発が進むので好ましくなく、１０００℃未満では水和
活性の高い鉱物相が得られ難くなるので好ましくない。
その鉱物相は特に限定されるものではないが、例えば８
ＣａＯ・Ｎａ2Ｏ・３Ａｌ2Ｏ3等のＣＮＡ化合物（結晶
質に限らず当該組成に近似の固溶体も含む）とＮａＡｌ
Ｏ2が主成分として共存するものが好ましく、このよう
なＣＮＡ化合物は非常に水和活性が高く、急結性生起の
作用源となる。成分（Ａ）中のＣａＯの含有量は２５〜
５０重量％、好ましくは３０〜４５重量％とする。２５
重量％未満では８ＣａＯ・Ｎａ2Ｏ・３Ａｌ2Ｏ3等の高
水和活性ＣＮＡ化合物の生成量が少なくなり、また５０
重量％を超えると遊離ＣａＯが大量に生成しやすくなる
ため、所望の急結性能が発現され難くなるので好ましく
ない。Ｎａ2Ｏの含有量は５〜２３重量％、好ましくは
１０〜２０重量％とする。５重量％未満では低温使用時
の急結性が低下し易く、２３重量％を超えると吸湿性が
高まり、急結剤の品質安定性に支障が生じるので好まし
くない。またＡｌ2Ｏ3の含有量は３０〜４８重量％、好
ましくは３５〜４５重量％とする。３０重量％未満では
水和活性の低下と短期の強度発現性が低下し、また４８
重量％を超えると活性度の乏しいアルミナ系化合物やコ
ランダム結晶が生成し易くなるので好ましくない。
【０００９】成分（Ｂ）は、急結剤セメントに加えた際
の硬化及び急結性を促すために配合される特定の高活性
アルミニウム化合物である。即ち、アルミン酸アルカ
リ、水酸化アルミニウム及び低結晶質乃至非晶質の酸化
アルミニウムから選ばれる１種又は２種以上を使用す
る。これらの成分は何れも、急結性を付与する凝集性の
大きい水和物であるエトリンガイドの早期生成における
アルミニウム供給源となると共に、急結剤の主剤となる
ＣＮＡ組成物の急結性を補うことができる。その含有量
成分は（Ａ）１００重量部に対しては３〜３１重量部と
し、好ましくは５〜２５重量部とする。３重量部未満で
は配合効果が殆ど得られず、３１重量部を超えてもその
配合効果が向上しない。アルミン酸アルカリとしてはア
ルミン酸ナトリウム、アルミン酸カリウム等が挙げられ
るが、その中でもアルミン酸ナトリウムが最も好まし
い。また低結晶質乃至非晶質の酸化アルミニウムは、高
い水和活性を発現するものであって、例えば、活性アル
ミナ、水硬性アルミナと称されているものやγ−Ａｌ2
Ｏ3、ベーマイトゲル等を挙げることができる。α−Ａ
ｌ2Ｏ3は結晶性が高く水和活性が乏しいので単独での使
用は好ましくない。
【００１０】成分（Ｃ）の炭酸アルカリは、アルミニウ
ムイオンをセメントペースト液相中への溶解を助長し、
早期反応を活発にし、急結性増進の補完的役割を担う。
炭酸アルカリとしては炭酸ナトリウム、炭酸カリウム等
が挙げられ、特に限定されないが、安価であることから
炭酸ナトリウムが好適である。その含有量は成分（Ａ）
１００重量部に対して１１〜３３重量部、好ましくは１
４〜２５重量部とする。３３重量部を超えるとセメント
の水和反応に支障を及ぼし、モルタル・コンクリートの
強度発現性が低下するので好ましくなく、１１重量部未
満では配合効果が十分発揮されないので好ましくない。
【００１１】成分（Ｄ）の石膏類は、無水石膏、半水石
膏、二水石膏、硫酸カルシウムの何れであっても良い。
石膏類は急結性をもたらす主要生成物であるエトリンガ
イドのＳＯ3源となり、また水に溶解してＳＯ4イオン濃
度を高めるため、前記成分（Ａ）の水和を穏やかに進行
させることができる。これにより早期急結性を抑制して
コワバリの発生を防ぎ、吹付け作業中の吹付け材圧送管
の目詰まりや閉塞を回避できる。石膏類の含有量は、成
分（Ａ）１００重量部に対して、５〜８５重量部、好ま
しくは３０〜７０重量部とする。５重量部未満ではカル
シウムアルミネート系水和物の相転移が起こりやすくな
って強度低下が起こるため好ましくなく、８５重量部を
超えると急結性確保が困難となるので好ましくない。
【００１２】本発明のモルタル・コンクリート用急結剤
は、前記成分（Ａ）〜（Ｄ）の各成分を混合したものを
焼成することにより得られ、また、急結性や強度発現性
及び吹付け作業性等に支障を及ぼさない範囲であれば、
成分（Ａ）〜（Ｄ）以外の他の成分を含むものであって
も良い。本発明モルタル・コンクリート用急結剤は、吹
付け材などとして高水比でも十分使用することができ、
通常、水セメント比（Ｗ／Ｃ）０．５以上、特に好適に
は０．５〜０．６５のコンクリート又はモルタルに対
し、セメント１００重量部に対し２〜１５重量部添加す
れば良い。
【００１３】また本発明のモルタル・コンクリート用急
結剤には、炭酸カルシウム、石灰石微粉末、珪石微粉末
等の早期反応性を有しないブレーン比表面積４０００cm
2／ｇ以上の微粉末の配合を必要としない。
【００１４】
【実施例】本発明を実施例により具体的に説明する。
〔使用原料〕
（Ａ）ＣＮＡ組成物
生石灰、日本金属（株）製純アルミナ及びソーダ灰（市
販工業製品）を混合したものを、ロータリーキルンで約
１３００℃で焼成した後、焼成物をボールミルで粉砕
し、ブレーン比表面積６０００cm2／ｇに粉末度を調整
して表１に記すＣＮＡ１〜４の組成物を作製した。得ら
れた組成物は粉末エックス線回折で調べた結果、ＣＮＡ
１〜３が何れも８ＣａＯ・Ｎａ2Ｏ・３Ａｌ2Ｏ3とＮａ
ＡｌＯ2が生成相の大部分を占めたが、ＣＮＡ４は８Ｃ
ａＯ・Ｎａ2Ｏ・３Ａｌ2Ｏ3の他に遊離ＣａＯと思われ
る相が生成し、ＮａＡｌＯ2は殆ど生成していなかっ
た。
【００１５】
【表１】
【００１６】（Ｂ）アルミニウム化合物
アルミン酸ソーダ（以下ＡＮと略記）又は純度９９％以
上の水酸化アルミニウム（以下ＡＨと略記）（何れも市
販工業製品）を使用した。
【００１７】（Ｃ）炭酸アルカリ
目開き１mmのふるい残分３％以下の市販工業製品（以下
Ｎと略記）を使用。
【００１８】（Ｄ）石膏
ブレーン比表面積約６０００cm2／ｇの粉末度の市販の
無水石膏（以下Ｇと略記）を使用。
【００１９】前記（Ａ）〜（Ｄ）の原料を表２に記す配
合量となるよう混合することで急結剤を作製した。
【００２０】
【表２】
【００２１】〔急結剤の評価方法〕急結剤の性能評価
は、下記方法に従って、セメントペーストのプロクター
貫入試験、ポンプ圧送性試験及びモルタル圧縮強度試験
を行った。
【００２２】（１）プロクター貫入試験
口径１０cm、高さ１６cmの円筒型ポリ容器にセメント
（普通ポルトランドセメント）４００ｇを秤りとり、こ
れに水２４０mL（水セメント比０．６０）加え、直径cm
の羽付ハンドミキサーを用いて１，０００rpmの回転数
で１分間混合した後、２８ｇ（セメントに対して７重量
％）の本発明の急結剤を添加して５秒間攪拌し、急結剤
を添加した直後から、セメントペーストの表面が全面表
面水が引けるまでの時間を表乾時間として測定した。こ
の表乾時間は急結性が生起し始めることを示す指標とし
て評価される。また、１／２０平方インチのプロクター
貫入針を使用して、１インチ貫入したときの抵抗値を、
急結剤添加してから１、２、６分後に測定した。プロク
ター貫入値は凝結に続く強度の増進を示すものであり、
これらの値よりモルタルやコンクリートの付着性の代用
特性を示すものである。
【００２３】（２）ポンプ圧送試験
ポンプ圧送試験は、簡易モルタル吹付け試験装置を用い
てモルタルのポンプ送りによる脈動の生じ具合により評
価した。水セメント比０．６、砂セメント比２に調整し
たモルタルを作製し、これを空気圧送し、ノズル先端で
急結剤を７％添加した。このときのポンプ圧送時の脈動
の状態を観察した。評価は、「多少なりとも脈動が見ら
れたもの」を「×」、「脈動が見られなかったもの」を
「○」とした。
【００２４】（３）モルタル圧縮強度試験
本発明の中で代表的な３種について、上記（２）と同じ
配合のモルタルについて（２）と同じ量の急結剤を添加
し、材齢３時間及び１日、２８日のモルタル圧縮強度を
測定した。比較例として、急結剤無添加の場合の強度及
び従来の急結剤を使用した場合の強度を測定した。
【００２５】〔評価結果〕
（１）プロクター貫入値及び付着性能評価試験結果を表
３に示す。本発明品１〜２はＣＮＡとして８ＣａＯ・Ｎ
ａ2Ｏ・３Ａｌ2Ｏ3（以下ＮＣ8Ａと称す）の含有量が比
較的少なく、ＮａＡｌＯ2含有量が比較的多い場合であ
り、本発明品３〜６はＣＮＡとしてＮＣ8Ａ3の含有量が
比較的多い場合である。何れもその他の無機塩類を適切
に配合する事により良好なプロクター値を発現し、付着
性の良好なものが得られている。
（２）一方、比較品は１分値が低いか、その後のプロク
ター値の増進が少ない。結果として付着性が劣るものと
なっており、急結剤として実用に供しない。
【００２６】
【表３】【００２７】（３）圧縮強度試験結果を表４に示す。本
発明品は、材齢３時間で３Ｎ／mm2以上の強度を発現
し、材齢１日でも１０Ｎ／mm2以上の強度を発現する。
また、材齢２８日の強度発現性も良好である。比較品で
は材齢１日までの強度発現は良好な場合もあるが、材齢
２８日の強度発現性が劣り実用性に乏しくなる。
【００２８】
【表４】
【００２９】
【発明の効果】本発明の急結剤は、急結剤添加直後の瞬
結（コワバリ）を制御することによりポンプ圧送時のト
ラブルを防止できるとともに、高水セメント比でも吹付
け後速やかに硬化することができ、しかも吹付けコンク
リートなどに具備すべき特性である高い初期強度及び安
定した長期強度を発現するものである。Description: BACKGROUND OF THE INVENTION [0001] The present invention relates to a high water ratio
The present invention relates to a quick setting agent for mortar / concrete, which has high strength and is suitable for spraying. 2. Description of the Related Art When an admixture having excellent hydration activity is mixed with cement, the setting and setting speed of the cement can be adjusted, whereby the initial strength of concrete and mortar becomes extremely high, and It can be extremely short.
In addition, when a quick-setting agent having such performance is used, it can be widely used in a spraying method in which concrete or mortar is sprayed on the top of a tunnel, under a bridge, or the like. In recent years, construction by the spraying method has increased due to its simplicity, high construction efficiency, and the like, and accordingly, the required performance of the quick-setting agent has been further increased. That is, the quick-setting agent has a high adhesiveness, a low rebound at the time of spraying, a quick setting, and it hardens very quickly after the application, and then has a short-term strength development of about 3 hours and a material age of 28 days. It is required that the strength developability is high. [0003] As quick-setting agents satisfying such properties,
Known are those mainly composed of alkali metal aluminates and those mainly composed of molten calcium aluminate. These quick-setting agents generate hydrates with high cohesive strength in the sprayed mortar and concrete, and are designed to give quick-setting properties. A high-strength type that can give higher strength because it interferes with the hydration reaction of cement, and the phenomenon that the long-term strength after hardening is significantly lower than when no quick-setting agent is added Of the quick setting agent is necessary for the construction work. On the other hand, the quick setting performance of the quick setting agent as described above decreases as the mixing water amount at the time of cement kneading increases (high water ratio), so that it is used at a low water ratio of 0.5 or less. You. However, when the amount of water is reduced, the pumping pipe is likely to be clogged when the material is pumped during spraying, and the pumping resistance and instantaneous setting due to the increase in viscosity of the pumping material are strengthened. There has been a problem that pulsation is likely to occur and blow spots are likely to occur. [0005] Accordingly, the present invention is intended to be used at a high water ratio of more than 0.5, which is less likely to cause blockage and blow spots of the spraying feed pipe when used as a spraying material. However, it is an object of the present invention to provide a quick-setting agent for mortar and concrete capable of exhibiting high strength development over a short period to a medium-to-long period while maintaining desired quick-setting performance. Means for Solving the Problems The present inventors have conducted studies to solve the above problems, and as a result, have found that a CaO—Na 2 O—Al 2 O 3 based composition having a relatively low CaO content is obtained. As a main component, by adding a specific inorganic salt compound having a reduced total amount of alkali having an action of complementing the quick-setting property, a high strength developability while maintaining excellent quick-setting properties even at a high water ratio. The present inventors have found that a quick-setting agent having the same can be obtained, and have completed the present invention. That is, the present invention provides the following components (A) to
(D): (A) calcined at 1000 to 1400 ° C., CaO 25
50 wt%, Na 2 O5~23 wt% and Al 2 O 3
CaO-Na 2 O with 30 to 48 wt% of the chemical composition
-Al 2 O 3 -based composition: 100 parts by weight, (B) one or more selected from alkali aluminate, aluminum hydroxide and low crystalline to amorphous aluminum oxide: 3 to 31 parts by weight, (C) The present invention provides a quick setting agent for mortar / concrete containing 11 to 33 parts by weight of alkali carbonate and (D) gypsum: 5 to 85 parts by weight. [0008] The component (A) constituting the quick-setting agent for mortar and concrete of the present invention is CaO-Na 2 O-
Al 2 O 3 based compositions (hereinafter referred to as "CNA".) A, CaO, mixture composition firing comprising at 1000 to 1400 ° C. which was specific mixing ratio of Na 2 O and Al 2 O 3 It is. If the sintering temperature exceeds 1400 ° C., the volatilization of Na 2 O proceeds, which is not preferable. If it is lower than 1000 ° C., it is difficult to obtain a mineral phase having high hydration activity.
The mineral phase is not particularly limited.
CaO · Na 2 O · 3Al CNA compounds such 2 O 3 (also including a solid solution of the approximate to the composition is not limited to crystalline) NaAl
It is preferable that O 2 coexists as a main component, and such a CNA compound has a very high hydration activity and becomes an action source of quick-setting. The content of CaO in the component (A) is 25 to
It is 50% by weight, preferably 30 to 45% by weight. 25
The less the amount of Kazu Takamizu active CNA compounds such 8CaO · Na 2 O · 3Al 2 O 3 is less than wt%, also 50
If the content exceeds% by weight, a large amount of free CaO is easily generated, and it is difficult to achieve desired quick-setting performance. The content of Na 2 O is 5 to 23% by weight, preferably 10 to 20% by weight. If the amount is less than 5% by weight, the quick-setting property at the time of use at a low temperature tends to decrease, and if it exceeds 23% by weight, the hygroscopicity is increased and the quality stability of the quick-setting agent is undesirably deteriorated. The content of Al 2 O 3 is 30 to 48% by weight, preferably 35 to 45% by weight. If the amount is less than 30% by weight, the hydration activity and short-term strength development are reduced, and
If the content is more than 10% by weight, an alumina-based compound having a low activity or corundum crystal is easily formed, which is not preferable. [0009] Component (B) is a specific highly active aluminum compound formulated to promote hardening and quick setting when added to the quick setting cement. That is, one or more selected from alkali aluminate, aluminum hydroxide, and low-crystalline to amorphous aluminum oxide are used. All of these components serve as a source of aluminum in the early production of an ettrine guide, which is a highly cohesive hydrate that provides quick-setting properties, and a quick-setting property of a CNA composition that is a main component of the quick-setting agent Can be supplemented. The content component is 3 to 31 parts by weight, preferably 5 to 25 parts by weight, based on 100 parts by weight of (A). If the amount is less than 3 parts by weight, almost no compounding effect is obtained, and if it exceeds 31 parts by weight, the compounding effect is not improved. Examples of the alkali aluminate include sodium aluminate and potassium aluminate, and among them, sodium aluminate is most preferable. Low-crystalline to amorphous aluminum oxides exhibit high hydration activity, for example, those called active alumina and hydraulic alumina, and γ-Al 2
O 3 , boehmite gel and the like can be mentioned. α-A
Since l 2 O 3 has high crystallinity and poor hydration activity, it is not preferable to use it alone. The alkali carbonate of the component (C) promotes the dissolution of aluminum ions into the liquid phase of the cement paste,
Encourage early response and play a complementary role in promoting rapid setting.
Examples of the alkali carbonate include sodium carbonate and potassium carbonate, and are not particularly limited. However, sodium carbonate is preferable because of its low cost. Its content depends on the component (A)
11 to 33 parts by weight, preferably 1 to 100 parts by weight
4 to 25 parts by weight. If the amount exceeds 33 parts by weight, the hydration reaction of the cement is hindered, and the strength development of the mortar / concrete is unpreferably reduced. The gypsum of the component (D) may be any of anhydrous gypsum, gypsum hemihydrate, gypsum dihydrate and calcium sulfate.
Gypsum serves as a source of SO 3 for etrin guide, which is a main product that causes quick setting, and dissolves in water to increase the concentration of SO 4 ions, so that the hydration of the component (A) proceeds gently. Can be. As a result, the quick-setting property is suppressed to prevent the occurrence of cracks and clogging or blockage of the spraying material pressure-feeding pipe during the spraying operation can be avoided. The content of the gypsum is 5 to 85 parts by weight, preferably 30 to 70 parts by weight, based on 100 parts by weight of the component (A). If the amount is less than 5 parts by weight, phase transition of the calcium aluminate-based hydrate is likely to occur, resulting in a decrease in strength, and if it exceeds 85 parts by weight, it is difficult to secure quick-setting properties. The quick setting agent for mortar / concrete of the present invention is obtained by firing a mixture of the above components (A) to (D). If it is within the range that does not affect the attachment workability, etc.
It may contain components other than the components (A) to (D). The mortar / concrete quick-setting admixture of the present invention can be sufficiently used even at a high water ratio as a spraying material,
Normally, 2 to 15 parts by weight of cement or 100 parts by weight may be added to concrete or mortar having a water / cement ratio (W / C) of 0.5 or more, particularly preferably 0.5 to 0.65. The quick-setting admixture for mortar / concrete according to the present invention also has a Blaine specific surface area of 4,000 cm which does not have early reactivity such as calcium carbonate, limestone fine powder and silica stone fine powder.
No compounding of fine powder of 2 / g or more is required. EXAMPLES The present invention will be described more specifically with reference to examples. [Raw Materials] (A) A mixture of calcined lime of CNA composition, pure alumina manufactured by Nippon Metal Co., Ltd. and soda ash (commercially available industrial product) is fired at about 1300 ° C. in a rotary kiln, and the fired material is pulverized by a ball mill. Then, the fineness was adjusted to a Blaine specific surface area of 6000 cm 2 / g to prepare compositions of CNAs 1 to 4 shown in Table 1. The obtained composition was analyzed by powder X-ray diffraction.
Even 1-3 are all 8CaO · Na 2 O · 3Al 2 O 3 and Na
AlO 2 accounted for the majority of the product phase, whereas CNA 4
phase seems free CaO is produced in addition to the aO · Na 2 O · 3Al 2 O 3, NaAlO 2 was not generated almost. [Table 1] (B) Aluminum Compound Sodium aluminate (hereinafter abbreviated as AN) or aluminum hydroxide having a purity of 99% or more (hereinafter abbreviated as AH) (all commercially available industrial products) was used. (C) A commercially available industrial product (hereinafter abbreviated as N) having a sieve residue of 3% or less with an alkali carbonate opening of 1 mm is used. (D) Gypsum Blane A commercially available anhydrous gypsum (hereinafter abbreviated as G) having a fineness of about 6000 cm 2 / g is used. The quick-setting agents were prepared by mixing the raw materials (A) to (D) so as to have the compounding amounts shown in Table 2. [Table 2] [Evaluation method of quick-setting agent] The performance of the quick-setting agent was evaluated by performing a proctor penetration test, a pumping test and a mortar compressive strength test of the cement paste in accordance with the following methods. (1) Proctor penetration test 400 g of cement (ordinary Portland cement) was weighed into a cylindrical plastic container having a diameter of 10 cm and a height of 16 cm, and 240 mL of water (water-cement ratio 0.60) was added thereto.
After mixing with a winged hand mixer at 1,000 rpm for 1 minute, 28 g (7% by weight based on cement) of the quick setting agent of the present invention was added and stirred for 5 seconds. Immediately after the addition of water, the time until the surface of the cement paste was completely drained was measured as the surface drying time. The surface drying time is evaluated as an index indicating that quick setting starts to occur. Also, using a 1/20 square inch proctor penetrating needle, the resistance value when penetrating 1 inch,
It was measured 1, 2, and 6 minutes after the addition of the quick setting agent. Proctor intrusion values indicate an increase in strength following coagulation,
These values indicate the substitute properties of mortar and concrete adhesion. (2) Pump pumping test The pump pumping test was evaluated by using a simple mortar spraying test device by the degree of pulsation caused by pumping the mortar. A mortar adjusted to a water-cement ratio of 0.6 and a sand-cement ratio of 2 was prepared, pneumatically fed, and 7% of a quick setting agent was added at a nozzle tip. The state of pulsation at the time of pumping at this time was observed. The evaluation was “x” for “somewhat showed pulsation” and “O” for “no pulsation”. (3) Mortar Compressive Strength Test With respect to three typical mortars of the present invention, the same amount of a quick setting agent as in (2) was added to a mortar having the same composition as in (2) above, and a material age of 3 hours And the mortar compressive strength of 1 day and 28 days was measured. As comparative examples, the strength when no quick-setting agent was added and the strength when a conventional quick-setting agent was used were measured. [Evaluation Results] (1) Table 3 shows the results of the test for evaluating the penetration of the proctor and the adhesion performance. The present invention products 1 and 2 are 8CaO · N as CNA.
a 2 O · 3Al 2 O 3 ( hereinafter referred to as NC 8 A) is relatively small content of a case NaAlO 2 content is relatively large, the present invention product 3-6 of NC 8 A 3 as CNA This is the case when the content is relatively large. In any case, by appropriately blending other inorganic salts, a good Proctor value is exhibited, and a material having good adhesion is obtained. (2) On the other hand, the comparison product has a low one-minute value or a small increase in the proctor value thereafter. As a result, the adhesiveness is poor, and it is not practically used as a quick-setting binder. [Table 3] (3) Table 4 shows the results of the compression strength test. The product of the present invention exhibits a strength of 3 N / mm 2 or more at a material age of 3 hours, and exhibits a strength of 10 N / mm 2 or more even at a material age of 1 day.
In addition, the strength development at 28 days of age is also good. In the comparative product, the strength development up to one day of age may be good, but the strength development at 28 days of age is inferior and practicality is poor. [Table 4] The quick-setting agent of the present invention can prevent trouble at the time of pumping by controlling the instantaneous setting (warpage) immediately after the addition of the quick-setting agent, and can be used even after spraying at a high water cement ratio. It can be quickly cured, and exhibits high initial strength and stable long-term strength, which are characteristics to be provided for shotcrete and the like.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 武広 実 山口県小野田市大字小野田6276番地 太平 洋マテリアル株式会社内 (72)発明者 宇智田 俊一郎 山口県小野田市大字小野田6276番地 太平 洋マテリアル株式会社内 Ｆターム(参考） 4G012 PB03 PB05 PB08 PB11 PC06 PE04 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Minoru Takehiro 6276 Onoda, Onoda-shi, Yamaguchi Prefecture Taihei Yo Materials Co., Ltd. (72) Inventor Shunichiro Uchida 6276 Onoda, Onoda-shi, Yamaguchi Prefecture Taihei Yo Materials Co., Ltd. F term (reference) 4G012 PB03 PB05 PB08 PB11 PC06 PE04
Claims (1)
〜５０重量％、Ｎａ2Ｏ５〜２３重量％及びＡｌ2Ｏ3
３０〜４８重量％の化学成分を有するＣａＯ−Ｎａ2Ｏ
−Ａｌ2Ｏ3系組成物：１００重量部、 （Ｂ）アルミン酸アルカリ、水酸化アルミニウム及び低
結晶質乃至非晶質の酸化アルミニウムから選ばれる１種
以上：３〜３１重量部、 （Ｃ）炭酸アルカリ：１１〜３３重量部、 （Ｄ）石膏類：５〜８５重量部 を含有するモルタル・コンクリート用急結剤。1. The following components (A) to (D): (A) calcined at 1000 to 1400 ° C., and CaO 25
50 wt%, Na 2 O5~23 wt% and Al 2 O 3
CaO-Na 2 O with 30 to 48 wt% of the chemical composition
-Al 2 O 3 -based composition: 100 parts by weight, (B) one or more selected from alkali aluminate, aluminum hydroxide and low crystalline to amorphous aluminum oxide: 3 to 31 parts by weight, (C) A quick setting agent for mortar / concrete, containing 11 to 33 parts by weight of alkali carbonate and (D) gypsum: 5 to 85 parts by weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002019837A JP2003221264A (en) | 2002-01-29 | 2002-01-29 | Quick setting agent for mortar or concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002019837A JP2003221264A (en) | 2002-01-29 | 2002-01-29 | Quick setting agent for mortar or concrete |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003221264A true JP2003221264A (en) | 2003-08-05 |
Family
ID=27743534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002019837A Pending JP2003221264A (en) | 2002-01-29 | 2002-01-29 | Quick setting agent for mortar or concrete |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003221264A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006342027A (en) * | 2005-06-10 | 2006-12-21 | Denki Kagaku Kogyo Kk | Quick setting agent, quick setting slurry, spraying material, and spraying method using the same |
| JP2014088296A (en) * | 2012-10-31 | 2014-05-15 | Taiheiyo Material Kk | Accelerator |
| CN114920485A (en) * | 2022-07-04 | 2022-08-19 | 中国水利水电第七工程局有限公司 | Slow-release additive for ultrahigh early-strength sprayed concrete and preparation method thereof |
-
2002
- 2002-01-29 JP JP2002019837A patent/JP2003221264A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006342027A (en) * | 2005-06-10 | 2006-12-21 | Denki Kagaku Kogyo Kk | Quick setting agent, quick setting slurry, spraying material, and spraying method using the same |
| JP2014088296A (en) * | 2012-10-31 | 2014-05-15 | Taiheiyo Material Kk | Accelerator |
| CN114920485A (en) * | 2022-07-04 | 2022-08-19 | 中国水利水电第七工程局有限公司 | Slow-release additive for ultrahigh early-strength sprayed concrete and preparation method thereof |
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