JP2003002724A - High fluidity concrete composition and producing method thereof - Google Patents
High fluidity concrete composition and producing method thereofInfo
- Publication number
- JP2003002724A JP2003002724A JP2001187850A JP2001187850A JP2003002724A JP 2003002724 A JP2003002724 A JP 2003002724A JP 2001187850 A JP2001187850 A JP 2001187850A JP 2001187850 A JP2001187850 A JP 2001187850A JP 2003002724 A JP2003002724 A JP 2003002724A
- Authority
- JP
- Japan
- Prior art keywords
- concrete
- fine powder
- fluidity concrete
- recycled
- powder
- 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
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
- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/04—Waste materials; Refuse
- C04B18/16—Waste materials; Refuse from building or ceramic industry
- C04B18/167—Recycled materials, i.e. waste materials reused in the production of the same materials
-
- 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
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Civil Engineering (AREA)
- Ceramic Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は高流動コンクリート
組成物及びその製造方法に係り、特にコンクリートから
得た再生微粉末を混和材として用いるようにした高流動
コンクリート組成物及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-fluidity concrete composition and a method for producing the same, and more particularly to a high-fluidity concrete composition in which recycled fine powder obtained from concrete is used as an admixture and a method for producing the same.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】高流動
コンクリートは、材料分離を低減する方法によって大き
く増粘剤系、粉体系の２つの種類に分けることができ
る。後者では適度な材料分離抵抗性を得るために粉体量
を多くしている。一般に粉体量の増加はセメント量を増
やすことによって行われるが、セメント単味として扱
い、セメント量を増加すると強度が高くなり、過剰品質
となって経済的でなく、硬化時の水和熱も大きくなり、
温度ひび割れ等のおそれもある。こうした問題に対処す
るため、粉体混和材として石灰石微粉末を混入する方法
も適用されているが、微粉末の投入に専用設備が必要に
なるという問題があった。このように、比較的低強度の
高流動コンクリートの製造のための不都合が明らかにさ
れていた。2. Description of the Related Art High-fluidity concrete can be roughly classified into two types, a thickener system and a powder system, by a method of reducing material separation. In the latter case, the amount of powder is increased in order to obtain appropriate material separation resistance. Generally, the amount of powder is increased by increasing the amount of cement, but it is treated as cement alone, and increasing the amount of cement increases the strength, resulting in excess quality and not economical, and the heat of hydration during hardening is also Getting bigger,
There is also a risk of temperature cracks. In order to deal with such a problem, a method of mixing limestone fine powder as a powder admixture is also applied, but there is a problem that a dedicated facility is required for charging the fine powder. Thus, the inconvenience for the production of relatively low-strength, high-fluidity concrete has been revealed.
【０００３】また、粉体系の高流動コンクリートでは、
細骨材の表面水率の変動によりスランプフローが大きく
変化するため、それを防止するために一種の増粘剤（分
離低減剤）を添加した、いわゆる併用系の高流動コンク
リートもあるが、高性能ＡＥ減水剤との相性や凝結硬化
速度への影響もあり、温度変化など変動要因の多い現場
での取扱いは容易でなかった。Further, in powder-type high-fluidity concrete,
Since the slump flow changes greatly due to the fluctuation of the surface water ratio of the fine aggregate, there is a so-called combination type high fluidity concrete in which a kind of thickener (separation reducing agent) is added to prevent it. Performance AE It was not easy to handle in the field where there are many fluctuation factors such as temperature change, due to the compatibility with the water reducing agent and the influence on the setting and hardening rate.
【０００４】一方、近年、建設廃棄物処理の問題がクロ
ーズアップされており、出願人もコンクリート廃材を再
度コンクリート構造物へと適用するために、コンクリー
ト廃材から、バージン骨材と同等の品質を有する再生骨
材を製造することが可能なコンクリート資源循環システ
ムに関する研究開発を進めている。このコンクリート廃
材を用いたコンクリート資源循環システムにおける再生
骨材製造プラントでは、破砕された解体コンクリートは
加熱塔において３００℃程度に加熱し、内部の残留水分
を除去して脱水状態にし、内部の結合状態を脆弱にして
から磨砕することで、粗骨材、細骨材を粒径ごとに分類
でき、さらに微粉末を集塵することですべての材料を再
利用の対象とすることができる。On the other hand, in recent years, the problem of construction waste treatment has been highlighted, and the applicant has the same quality as the virgin aggregate from the concrete waste material in order to apply the concrete waste material to the concrete structure again. We are conducting research and development on a concrete resource circulation system that can manufacture recycled aggregate. In a recycled aggregate manufacturing plant in a concrete resource circulation system using this concrete waste material, the crushed demolition concrete is heated to about 300 ° C in a heating tower to remove the residual water inside and to be dehydrated, and the internal bonded state The coarse aggregate and the fine aggregate can be classified according to the particle size by making the fragile and crushed, and all the materials can be reused by collecting the fine powder.
【０００５】これらの再生材料のうち、微粉末はセメン
ト水和物を主成分とするため、セメント原料として再利
用可能であるが、セメントエ場への輸送費の他、多大な
処理費用も払わなければならず、リサイクルがコストア
ップヘつながるといった問題があった。この微粉末は比
表面積が４，０００m2/g以上の安定した品質を有してい
る。そこで、出願人は、上述の高流動コンクリートの粉
体として用いることで、比較的低い強度の高流動コンク
リートを得ることができる点に着目して、再生細骨材に
対して所定の割合で再生微粉末を混合した材料を用いた
高流動コンクリート組成物を提供することとした。Among these recycled materials, fine powder is mainly composed of cement hydrate and therefore can be reused as a raw material for cement. However, in addition to transportation cost to the cement plant, a great deal of processing cost must be paid. However, there is a problem that recycling leads to higher costs. This fine powder has a stable quality with a specific surface area of 4,000 m 2 / g or more. Therefore, the Applicant has noticed that by using the powder of the above-mentioned high-fluidity concrete, it is possible to obtain high-fluidity concrete with relatively low strength, and the recycled fine aggregate is recycled at a predetermined ratio. It was decided to provide a high-fluidity concrete composition using a material mixed with fine powder.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
に、本発明は粉体系混和材を添加して得られる高流動コ
ンクリート組成物であって、前記粉体系混和材としてコ
ンクリート廃材を加熱、磨砕して得られた再生微粉末を
用い、そのうち再生微粉末質量（Ｂ）が使用細骨材質量
（Ｓ）に対して１２％＜Ｂ／（Ｂ＋Ｓ）＜２０％となる
ように調合されたことを特徴とする。In order to achieve the above object, the present invention is a high-fluidity concrete composition obtained by adding a powder-based admixture, wherein concrete waste is heated as the powder-based admixture, Regenerated fine powder obtained by grinding was blended such that the regenerated fine powder mass (B) was 12% <B / (B + S) <20% with respect to the amount of fine bone material used (S). It is characterized by that.
【０００７】その製造方法として、コンクリート廃材を
加熱、磨砕して分級された再生細骨材と再生微粉末とを
所定質量比で混合してプレミックス材料を製造し、該プ
レミックス材料と他の材料とを練り混ぜて低強度の高流
動コンクリートを製造するようにしたことを特徴とす
る。As a manufacturing method thereof, recycled fine aggregate and recycled fine powder, which are classified by heating and grinding concrete waste materials, are mixed at a predetermined mass ratio to produce a premix material, and the premix material and other materials are mixed. It is characterized in that low-strength, high-fluidity concrete is produced by kneading with the above materials.
【０００８】一般に粉体系の高流動コンクリートは細骨
材の表面水率が変動するため、スランプフローが安定し
にくい。しかし絶対乾燥状態の再生細骨材を使用するこ
とにより、安定したスランプフローの高流動コンクリー
トを提供できる。Generally, in powder-type high-fluidity concrete, the surface water ratio of the fine aggregate fluctuates, so that the slump flow is difficult to stabilize. However, by using recycled fine aggregate in an absolutely dry state, it is possible to provide a highly fluid concrete with a stable slump flow.
【０００９】[0009]
【発明の実施の形態】以下、本発明の高流動コンクリー
ト組成物及びその製造方法の一実施の形態について、添
付図面を参照して説明する。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the high fluidity concrete composition of the present invention and the method for producing the same will be described below with reference to the accompanying drawings.
【００１０】［再生骨材、再生微粉末の製造］本発明で
使用する再生細骨材、微粉末の製造工程について説明す
る。本発明ではコンクリート廃材から所望の再生骨材を
得るために、公知の再生骨材製造プラントで「加熱すり
もみ法」を採用している。この加熱すりもみ法では、ま
ず破砕したコンクリート廃材（いわゆるコンクリートが
ら）を加熱塔の炉内に投入し、約３００℃程度に加熱す
る。その後、磨砕設備により物理的にすりもむ（擦り揉
む）ことで磨砕し、さらに公知の分級装置を介して分級
し、所望の粒径の再生骨材を得ることができる。また、
このとき再生細骨材、再生粗骨材は、従来の骨材と同等
の品質を有するため、一般の構造コンクリートの骨材と
して使用することができる。この加熱すりもみ法によっ
て製造された再生細骨材、再生粗骨材は絶乾状態にあ
る。また、再生骨材と同時に得られる再生微粉末は、そ
の比表面積が４，０００〜１０，０００cm2/g程度あ
り、通常のセメントより極めて細かい粒子である。[Production of Recycled Aggregate and Recycled Fine Powder] The production process of recycled fine aggregate and fine powder used in the present invention will be described. In the present invention, in order to obtain the desired recycled aggregate from the concrete waste material, the "heated grinding method" is adopted in a known recycled aggregate manufacturing plant. In this heating-rubbing method, first, crushed concrete waste material (so-called concrete waste) is put into the furnace of a heating tower and heated to about 300 ° C. Then, it is ground by physically grinding (rubbing) with a grinding facility and further classified by a known classifying device to obtain a recycled aggregate having a desired particle size. Also,
At this time, since the recycled fine aggregate and recycled coarse aggregate have the same quality as conventional aggregates, they can be used as aggregates of general structural concrete. The recycled fine aggregate and recycled coarse aggregate produced by the heat-rubbing method are in an absolutely dry state. Further, the regenerated fine powder obtained at the same time as the regenerated aggregate has a specific surface area of about 4,000 to 10,000 cm 2 / g and is a finer particle than ordinary cement.
【００１１】［高流動コンクリートの調合］本発明で
は、比較的低強度の高流動コンクリートの製造を目的と
し、具体的には設計基準強度を３６N/mm2以下、呼び強
度２１〜２４のコンクリートを想定している。そこで、
粉体系の高流動コンクリートの材料分離抵抗性を高める
ために、上述の再生微粉末をセメントに対して所定割合
で混合するものとした。このとき、材料分離抵抗性と強
度発現との関係を考慮し、本発明の粉体系高流動コンク
リートにおける使用細骨材質量（Ｓ）に対しての微粉末
質量（Ｂ）の混合比率を１２％＜Ｂ／（Ｂ＋Ｓ）＜２０
％とした。混合比率が１２％以下では、十分な材料分離
抵抗性が得られず、スランプフローが６５cmを越えた場
合分離するおそれがあり、一方２０％以上では、粘性が
高くなり、スランプフローが５０cm程度の場合に、充て
ん性が低下するおそれがある。また、微粉末の粉末度品
質としては、比表面積５，０００〜７，０００cm2/g程
度のものを用いることとする。[Mixing of high-fluidity concrete] The present invention aims to produce a relatively low-strength high-fluidity concrete. Specifically, concrete having a design standard strength of 36 N / mm 2 or less and a nominal strength of 21 to 24 is used. I am assuming. Therefore,
In order to improve the material separation resistance of powder-type high-fluidity concrete, the above-mentioned regenerated fine powder was mixed with cement at a predetermined ratio. At this time, considering the relationship between material separation resistance and strength development, the mixing ratio of the fine powder mass (B) to the amount of fine bone material used (S) in the powder-type high-fluidity concrete of the present invention is 12%. <B / (B + S) <20
%. If the mixing ratio is 12% or less, sufficient resistance to material separation cannot be obtained, and if the slump flow exceeds 65 cm, separation may occur, while if it is 20% or more, the viscosity becomes high and the slump flow is about 50 cm. In this case, the filling property may decrease. The fineness of the fine powder has a specific surface area of about 5,000 to 7,000 cm 2 / g.
【００１２】［高流動コンクリートの製造］本実施の形
態では、図１に示したように、再生骨材製造プラント
で、所定の加熱、磨砕、分級工程を経て製造された再生
細骨材と再生微粉末とを所定割合で混合してプレミック
ス材料を製造し、このプレミックス材料をレディミクス
トコンクリート製造プラントへ供給して使用している。
このとき、高流動コンクリートの調合として、本発明で
は所定のコンクリート強度を確保するために必要な単位
セメント量と単位微粉末量とが５００kg／m3程度となる
ように、再生細骨材に再生微粉末をプレミックスするこ
とが好ましい。[Manufacture of high-fluidity concrete] In the present embodiment, as shown in FIG. 1, a recycled fine aggregate manufactured through a predetermined heating, grinding, and classifying process in a recycled aggregate manufacturing plant is used. Regenerated fine powder is mixed at a predetermined ratio to produce a premix material, and this premix material is supplied to a ready mixed concrete production plant for use.
At this time, as a mixture of high-fluidity concrete, in the present invention, the recycled fine aggregate is recycled so that the unit cement amount and the unit fine powder amount required to secure a predetermined concrete strength are about 500 kg / m 3. It is preferred to premix the fine powder.
【００１３】また、前述したように再生細骨材は絶乾状
態にあるので、吸水率に応じた水量を、調合上の単位水
量に加算して加えるものとする。また、再生粗骨材に対
しては必要に応じて散水により含水状態にする等の処置
を行うことが好ましい。As described above, since the recycled fine aggregate is in an absolutely dry state, the amount of water corresponding to the water absorption rate is added to the unit amount of water in preparation. In addition, it is preferable that the recycled coarse aggregate is subjected to a treatment such as watering by sprinkling water if necessary.
【００１４】[0014]
【実施例】以下、実施例を通じて本発明の構成および効
果について説明する。
［使用材料、調合］本実施例における使用材料の各材料
調合一覧を表−１に示す。再生微粉末の比表面積は５，
６４０cm2/gである。また、本実施例ではセメントとし
て普通ポルトランドセメントを用いている。また、ポリ
カルボン酸系の高性能ＡＥ減水剤を用いスランプフロー
値の測定を行い、流動性の確認を行った。なお、再生細
骨材と再生微粉末は試験用のプレミックス材料として用
意し、このプレミックス材料のミキサー投入時における
材料の混合状態を目視確認する。EXAMPLES The constitution and effects of the present invention will be described below through examples. [Materials Used and Preparation] Table 1 shows a list of materials prepared for the materials used in this example. The specific surface area of regenerated fine powder is 5,
It is 640 cm 2 / g. In this embodiment, ordinary Portland cement is used as the cement. Further, the slump flow value was measured using a polycarboxylic acid type high performance AE water reducing agent to confirm the fluidity. The regenerated fine aggregate and the regenerated fine powder are prepared as a premix material for a test, and the mixed state of the premix material at the time of charging the mixer is visually confirmed.
【００１５】［表１］ [Table 1]
【００１６】［試験結果］材料練混ぜ時の性状確認、高
流動コンクリートとしての材料分離抵抗性、流動性の評
価をスランプフロー値測定、硬化後のコンクリート強度
測定を行った結果を表−２に示した。[Test Results] The results of the slump flow value measurement for the property confirmation at the time of mixing the materials, the evaluation of the material separation resistance as the high-fluidity concrete, the evaluation of the fluidity, and the measurement of the concrete strength after hardening are shown in Table-2. Indicated.
【００１７】［表２］ [Table 2]
【００１８】本実施例では、表−１に示した調合に基づ
いて設定し再生微粉末の混合比率をＢ／（Ｂ＋Ｓ）を１
２〜２０％程度とした場合に、表−２に示したように、
コンクリート製造時、施工時における材料の高流動性が
確保され、所望の強度が得られることが認められた。In this embodiment, the mixing ratio of the regenerated fine powder is set based on the formulation shown in Table-1 and B / (B + S) is set to 1
When it is set to about 2 to 20%, as shown in Table-2,
It was confirmed that the high fluidity of the material during concrete production and construction was ensured and the desired strength was obtained.
【００１９】[0019]
【発明の効果】以上に述べた方法により高流動コンクリ
ートを製造すると、細骨材に微粉末がプレミックスされ
ているため、生コン工場で微粉末を添加するための新た
な設備が必要なくなり、工事コスト低減になる。細骨材
が絶乾状態であるため、表面水率の変動による高流動コ
ンクリートの品質変動が生ぜず、管理しやすくなる。再
生細骨材、再生微粉末の有効利用によるコストダウンが
図れる等の効果が期待できる。[Effects of the Invention] When high-fluidity concrete is manufactured by the method described above, fine aggregate is premixed with fine powder, so new equipment for adding fine powder at the ready-mixed concrete plant is not required Cost reduction. Since the fine aggregate is in an absolutely dry state, the quality of the high-fluidity concrete does not fluctuate due to the fluctuation of the surface water ratio, and it is easy to manage. Effective use of recycled fine aggregate and recycled fine powder can be expected to bring about effects such as cost reduction.
【図１】本発明による高流動コンクリートの製造方法の
一実施の形態を示した作業フローチャート。FIG. 1 is a work flow chart showing an embodiment of a method for producing high-fluidity concrete according to the present invention.
Claims (2)
ンクリート組成物であって、前記粉体系混和材としてコ
ンクリート廃材を加熱、磨砕して得られた再生微粉末を
用い、そのうち再生微粉末質量（Ｂ）が使用細骨材質量
（Ｓ）に対して １２％＜Ｂ／（Ｂ＋Ｓ）＜２０％ となるように調合されたことを特徴とする高流動コンク
リート組成物。1. A high-fluidity concrete composition obtained by adding a powder-type admixture, wherein as the powder-type admixture, recycled fine powder obtained by heating and grinding concrete waste material is used, of which regenerated A high-fluidity concrete composition, characterized in that the fine powder mass (B) is blended so as to be 12% <B / (B + S) <20% with respect to the amount of fine bone material used (S).
れた再生細骨材と再生微粉末とを所定質量比で混合して
プレミックス材料を製造し、該プレミックス材料と他の
材料とを練り混ぜて低強度の高流動コンクリートを製造
するようにしたことを特徴とする高流動コンクリートの
製造方法。2. A premix material is produced by mixing recycled fine aggregate and recycled fine powder, which have been classified by heating and grinding a concrete waste material, in a predetermined mass ratio to produce the premix material and other materials. A method for producing high-fluidity concrete, characterized in that low-strength high-fluidity concrete is produced by kneading.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001187850A JP2003002724A (en) | 2001-06-21 | 2001-06-21 | High fluidity concrete composition and producing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001187850A JP2003002724A (en) | 2001-06-21 | 2001-06-21 | High fluidity concrete composition and producing method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003002724A true JP2003002724A (en) | 2003-01-08 |
Family
ID=19027077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001187850A Pending JP2003002724A (en) | 2001-06-21 | 2001-06-21 | High fluidity concrete composition and producing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003002724A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012025631A (en) * | 2010-07-23 | 2012-02-09 | Tokyo Electric Power Co Inc:The | Regenerated concrete comprising reclaimed material from waste concrete as main material, and method for producing the same, and method for processing waste concrete for obtaining the reclaimed material |
-
2001
- 2001-06-21 JP JP2001187850A patent/JP2003002724A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012025631A (en) * | 2010-07-23 | 2012-02-09 | Tokyo Electric Power Co Inc:The | Regenerated concrete comprising reclaimed material from waste concrete as main material, and method for producing the same, and method for processing waste concrete for obtaining the reclaimed material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3230390B2 (en) | Method for producing cement composition | |
| JP3230378B2 (en) | Cement composition | |
| CN108751865A (en) | Body refuse soil regeneration baking-free brick and preparation method thereof more than a kind of | |
| JP2004203733A (en) | Method of producing mortar/concrete, and cement used for producing mortar/concrete | |
| JPH09165244A (en) | Production of gypsum board | |
| WO2008138170A1 (en) | Dry powder mortar made from steel slag and a method for producing it | |
| CN107139325B (en) | A kind of method of wet grinding cement preparation ready-mixed concrete | |
| JPH11147750A (en) | Cement composition | |
| JP2000211956A (en) | Cement composition | |
| JP2015174433A (en) | Separated mixing method and separated mixing device | |
| JP6916509B2 (en) | Manufacturing method of premix cement composition | |
| JP5440905B2 (en) | Ultra-early strong cement composition and manufacturing method thereof | |
| JP2005231947A (en) | Method of treating steel slag to make aggregate | |
| CN106747013A (en) | Misfire concrete and preparation method thereof | |
| JP2003002724A (en) | High fluidity concrete composition and producing method thereof | |
| JP2020033225A (en) | Manufacturing method of artificial stone material | |
| JP2003025321A (en) | Method for determining composition of concrete | |
| JP2000128616A (en) | Production of cement composition | |
| CN112723854A (en) | Preparation method of multi-mineral waste composite admixture | |
| JP4781485B1 (en) | Split kneading method | |
| JP5919940B2 (en) | High water retention block and method for producing high water retention block | |
| CN108975848A (en) | A method of with oxidation rotary kiln tailings dry powder and mortar | |
| JP4824218B2 (en) | Method for producing colored concrete kneaded material | |
| JP3358715B2 (en) | Cement-based composition | |
| JPH06114824A (en) | Preparation of super-high-strength concrete and superfine powder mixture |