JP2012017227A - Waste concrete fine powder and method for recovering the same - Google Patents
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- 239000004567 concrete Substances 0.000 title claims abstract description 112
- 239000002699 waste material Substances 0.000 title claims abstract description 88
- 239000000843 powder Substances 0.000 title claims abstract description 81
- 238000000034 method Methods 0.000 title claims description 33
- 239000000463 material Substances 0.000 claims abstract description 33
- 239000004568 cement Substances 0.000 claims abstract description 28
- 239000002994 raw material Substances 0.000 claims abstract description 13
- 238000000227 grinding Methods 0.000 claims description 14
- 230000008569 process Effects 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 238000007873 sieving Methods 0.000 claims description 9
- 238000011084 recovery Methods 0.000 claims description 8
- 230000006872 improvement Effects 0.000 claims description 3
- 239000010419 fine particle Substances 0.000 abstract description 7
- 238000000926 separation method Methods 0.000 abstract description 7
- 238000012216 screening Methods 0.000 abstract 2
- 239000002689 soil Substances 0.000 abstract 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 12
- 239000011575 calcium Substances 0.000 description 9
- 239000002245 particle Substances 0.000 description 9
- 238000004064 recycling Methods 0.000 description 9
- 229910002092 carbon dioxide Inorganic materials 0.000 description 6
- 239000001569 carbon dioxide Substances 0.000 description 6
- 238000002076 thermal analysis method Methods 0.000 description 5
- 235000019738 Limestone Nutrition 0.000 description 4
- 239000011362 coarse particle Substances 0.000 description 4
- 239000006028 limestone Substances 0.000 description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- 239000006227 byproduct Substances 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000006386 neutralization reaction Methods 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000011150 reinforced concrete Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 150000004677 hydrates Chemical class 0.000 description 1
- 230000000887 hydrating effect Effects 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
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- 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
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- Processing Of Solid Wastes (AREA)
Abstract
Description
本発明は廃コンクリート微粉末及びその回収方法に係り、回収された廃コンクリート材の炭酸化状態を考慮して、適正な用途にリサイクル材料を利用出来るように分離して回収した廃コンクリート微粉末とその回収方法に関する。 The present invention relates to a waste concrete fine powder and a method for recovering the waste concrete, and considering the carbonation state of the recovered waste concrete material, the waste concrete fine powder separated and recovered so that the recycled material can be used for an appropriate use, and It relates to the recovery method.
従来、鉄筋コンクリート建築物等の解体工事に伴って発生するコンクリート廃材は、鉄筋を取り除いたコンクリート塊を、所定の破砕分級によって所定の道路舗装用骨材としてリサイクルされ、その大半が、ＲＣ４０等の再生粒調砕石として路盤材や工事用の地盤埋戻し材等の仮設材料として使用されている。しかし、これらの材料の需要は、近年増加しているリサイクル材の生産、供給量に対してそれほど多くはない。このため、将来的には、廃コンクリート材を高度処理することにより、再度コンクリート用の硬化材料あるいは良質の再生骨材としてリサイクルして利用することが望まれている。 Conventionally, the concrete waste generated by the demolition work of reinforced concrete buildings, etc., is recycled as a predetermined road pavement aggregate by a predetermined crushing classification of the concrete block from which the rebar has been removed, most of which is recycled from RC40, etc. It is used as temporary material such as roadbed material and ground backfill material for construction as granulated crushed stone. However, the demand for these materials is not so large with respect to the production and supply of recycled materials, which have been increasing in recent years. For this reason, in the future, it is desired that the waste concrete material is recycled and used again as a hardened material for concrete or a high-quality recycled aggregate by treating the waste concrete material at a high level.
しかしながら、良質の再生骨材を得るためには、コンクリート塊の破砕及び磨砕処理を行うため、コンクリート廃材重量の３０〜５０％程度の廃コンクリート微粉末（たとえば粒径０．６mm以下、比表面積５００cm2/g以上）が副次発生する。この微粉末は、そのままでは格別の用途がないため、その処分が大きな問題となり、コンクリートのリサイクルを阻害する要因となっており、この微粉末を廃棄処分することなく有効活用することが要請されている。 However, in order to obtain high-quality recycled aggregate, the concrete lump is crushed and ground, so it is about 30-50% of the concrete waste weight (for example, particle size 0.6mm or less, specific surface area) 500 cm 2 / g or more) is generated as a secondary. Since this fine powder has no special application as it is, its disposal becomes a major problem and is a factor that hinders the recycling of concrete, and it is requested that this fine powder be effectively used without being disposed of. Yes.
ところで、廃コンクリート微粉末は、再水和特性を有し、強度発現に寄与する成分を含むこともあり、セメント原料やセメントに混合する混合材として利用することが、資源循環の観点からは望ましいと考えられる。また、従来の石灰石を原料としたセメント製造プロセスにおける二酸化炭素排出の削減を考慮したとき、廃コンクリート微粉末を有効利用する際、発明者は、既往の研究および自らの研究において、以下の知見を得ている。
(1)廃コンクリート微粉末が炭酸化していなければ、焼成時に脱炭酸しないため、石灰石 をカルシウム源として利用する場合に比べ、大幅に二酸化炭素を削減できる
（非特許文献１参照）
(2)廃コンクリート微粉末が炭酸化していれば、セメント水和物の炭酸化による分解によ って生じたシリカゲルと炭酸カルシウムの影響で、水和性混合材として利用できる
（特願２００９−１０４６６４参照）。
(3)原料となる廃コンクリートのうち、粒子の表面積の大きい微粒分では破砕直後から炭 酸化が進行し、粗粒分では炭酸化の進行が遅い（非特許文献２参照）
By the way, waste concrete fine powder has rehydration characteristics and may contain components that contribute to the development of strength, and it is desirable from the viewpoint of resource recycling to be used as a cement raw material or a mixture mixed with cement. it is conceivable that. In addition, when considering the reduction of carbon dioxide emissions in the conventional cement manufacturing process using limestone as a raw material, the inventor has made the following knowledge in past research and his own research when using waste concrete fine powder effectively. It has gained.
(1) If the waste concrete fine powder is not carbonated, it will not be decarboxylated during firing, so carbon dioxide can be significantly reduced compared to using limestone as a calcium source (see Non-Patent Document 1).
(2) If the waste concrete fine powder is carbonated, it can be used as a hydrating mixture under the influence of silica gel and calcium carbonate produced by the decomposition of cement hydrate by carbonation (Japanese Patent Application No. 2009- 104664).
(3) Among the waste concrete used as raw material, carbonization proceeds immediately after crushing for fine particles with large particle surface area, and carbonation progresses slowly for coarse particles (see Non-Patent Document 2).
上述のような状況にあって、現状の廃コンクリート材のリサイクル工程では、再生骨材を製造する際に、副産物として発生する廃コンクリート微粉末を、炭酸化の程度によって分離回収する方法についての検討はまったく行われていない。たとえば発明者による非特許文献２に開示した研究は、ＣＯ2の固定化技術に着目したものであるため、リサイクル工程における廃コンクリート微粉末が、炭酸化が進行したものであるか、非炭酸化状態であるかの相違による再生材料としての適性については言及していない。
Under the circumstances described above, in the current recycling process of waste concrete materials, when manufacturing recycled aggregates, a study on how to separate and recover the waste concrete fine powder generated as a by-product according to the degree of carbonation Is not done at all. For example, since the research disclosed in Non-Patent
実際、廃コンクリート再生工程において回収される微粉末には、炭酸化しているものとしていないものが混在しているのが現状である。廃コンクリート材の再生工程において、炭酸化の進行の有無によって、再生材料を的確に分別し、それぞれの状態での廃コンクリート微粉末を分離回収することができれば、異なる硬化性状を示す微粉末を、それぞれ適正な用途で使用することができる。 Actually, the fine powder recovered in the waste concrete recycling process is mixed with what is not carbonized. In the recycling process of waste concrete material, if the recycled material can be accurately separated according to the presence or absence of the progress of carbonation, and the waste concrete fine powder in each state can be separated and recovered, fine powder showing different curing properties, Each can be used for proper purposes.
上述した(1)〜(3)の知見を踏まえると、炭酸化状態の廃コンクリート微粉末は、強度発現に寄与しないが、炭酸化の進行した廃コンクリート微粉末は、強度発現に寄与し、加熱処理することによりその強度発現は増加することが認められる。 Based on the findings of (1) to (3) above, the waste concrete fine powder in the carbonated state does not contribute to strength development, but the waste concrete fine powder that has advanced carbonation contributes to strength development and is heated. It is recognized that the strength expression increases by the treatment.
よって、分離回収した再生材料のうち、たとえばカルシウム源として炭酸化していないＣａ(ＯＨ）2やＣ−Ｓ−Ｈ等をセメント原料とすれば、従来のセメント製造工程に比べ、二酸化炭素排出を大幅に抑制できる。そこで、本発明の目的は、従来の技術が有する問題点を解消し、廃コンクリート材の状態に応じて、得られる廃コンクリート微粉末を適正に再利用できるようにした廃コンクリート微粉末及びその回収方法を提供することにある。 Therefore, among the recycled materials separated and recovered, for example, when Ca (OH) 2 or C—S—H, which is not carbonated as a calcium source, is used as the cement raw material, the carbon dioxide emission is greatly reduced compared to the conventional cement manufacturing process. Can be suppressed. Accordingly, an object of the present invention is to solve the problems of the prior art, and to recover waste concrete fine powder obtained by appropriately reusing the obtained waste concrete fine powder according to the state of the waste concrete material and its recovery It is to provide a method.
上記目的を達成するために、本発明の廃コンクリート微粉末の回収方法は、廃コンクリート塊を粗破砕する工程と、粗破砕されたコンクリート片をふるい分け分離する工程と、該ふるい分け分離工程によるふるい残留分を破砕・磨砕・分級し、再生粗骨材と再生細骨材と廃コンクリート微粉末とに分離回収する工程とからなる再生粗骨材、再生細骨材の製造工程において、前記ふるい残留分から廃コンクリート微粉末を分離して回収することを特徴とする。 In order to achieve the above object, the method for recovering waste concrete fine powder according to the present invention comprises a step of roughly crushing a waste concrete lump, a step of separating and separating a coarsely crushed concrete piece, and a sieve residue by the screen separation step. In the production process of recycled coarse aggregate and recycled fine aggregate, the process of crushing, grinding and classifying the fraction and separating and recovering it into recycled coarse aggregate, recycled fine aggregate and waste concrete fine powder It is characterized by separating and collecting waste concrete fine powder from the minute.
また、他の性状を示す廃コンクリート微粉末の回収方法として、廃コンクリート塊を粗破砕する工程と、粗破砕されたコンクリート片をふるい分け分離する工程と、該ふるい分け分離工程によるふるい通過分を破砕・磨砕・分級し、再生細骨材と廃コンクリート微粉末とに分離回収する工程とからなる再生細骨材の製造工程において、前記ふるい通過分から廃コンクリート微粉末を分離して回収することを特徴とする。 In addition, as a method for recovering waste concrete fine powder exhibiting other properties, a step of roughly crushing a waste concrete lump, a step of separating and separating the coarsely crushed concrete pieces, and crushing and separating the passage through the sieve separation step In the production process of reclaimed fine aggregate, which includes grinding and classifying and separating and collecting recycled fine aggregate and waste concrete fine powder, the waste concrete fine powder is separated and collected from the sieve passage And
これらの回収方法において、前記ふるい分け分離工程のふるい目は１０mmとすることが好ましい。 In these recovery methods, it is preferable that the sieve mesh in the sieving and separating step is 10 mm.
前記廃コンクリート微粉末の回収方法において、前記ふるい通過分を、加熱処理し、その後、破砕・磨砕・分級して前記廃コンクリート微粉末を回収することが好ましい。 In the method for recovering waste concrete fine powder, it is preferable to recover the waste concrete fine powder by heat-treating the sieve passage and then crushing, grinding, and classifying.
前記廃コンクリート微粉末は、ふるい残留分を破砕・磨砕・分級し、再生粗骨材と再生細骨材とともに得られ、未炭酸化状態であることを特徴とする。 The waste concrete fine powder is obtained by crushing, grinding and classifying the sieve residue, and is obtained together with recycled coarse aggregate and recycled fine aggregate, and is in an uncarbonated state.
前記廃コンクリート微粉末は、ふるい通過分を破砕・磨砕・分級し、再生細骨材とともに得られ、炭酸化状態にあることを特徴とする。 The waste concrete fine powder is obtained by crushing / grinding / classifying the portion passing through the sieve, obtaining together with recycled fine aggregate, and being in a carbonated state.
前記未炭酸化状態の廃コンクリート微粉末は、脱炭酸セメント原料とすることが好ましい。 The uncarbonated waste concrete fine powder is preferably used as a decarboxylated cement raw material.
前記炭酸化状態の廃コンクリート微粉末は、セメント混合材あるいは地盤改良材とすることが好ましい。 The carbonated waste concrete fine powder is preferably a cement mixed material or a ground improvement material.
本発明によれば、未炭酸化状態の廃コンクリート微粉末は、脱炭酸セメント原料として、炭酸化が進行した状態の廃コンクリート微粉末は、セメントに混合するセメント混合材として用いることができ、それぞれ回収された廃コンクリート材の炭酸化状態を考慮して、適正な用途に利用出来るという効果を奏する。 According to the present invention, the uncarbonated waste concrete fine powder can be used as a decarbonized cement raw material, and the waste concrete fine powder in the state of advanced carbonation can be used as a cement mixed material mixed with cement. In view of the carbonation state of the recovered waste concrete material, there is an effect that it can be used for an appropriate purpose.
以下、本発明の廃コンクリート微粉末の回収方法を実施するための形態として、以下の実施例について添付図面を参照して説明する。 Hereinafter, as embodiments for carrying out the method for recovering waste concrete fine powder of the present invention, the following examples will be described with reference to the accompanying drawings.
［廃コンクリート微粉末の分離回収の基本的考え方］
炭酸化の進行状態は、対象となる廃コンクリート材料の粒径により異なる。そこで、工程の最初に粗粒分と細粒分を分離する。そのうちの粗粒分を破砕・磨砕、分級して再生細骨材と粗骨材を製造し、副次生産される微粉末を回収する。この微粉末は、炭酸化が進行していない状態の微粉末(以下、未炭酸化廃コンクリート微粉末と記す。)である。一方、細粒分を破砕・磨砕して再生細骨材を製造し、微粉末を回収すると、炭酸化が進行した微粉末(以下、炭酸化廃コンクリート微粉末と記す。)が得られる。
[Basic concept of separation and recovery of waste concrete fine powder]
The progress of carbonation varies depending on the particle size of the target waste concrete material. Therefore, the coarse and fine particles are separated at the beginning of the process. Of these, the coarse particles are crushed, ground and classified to produce recycled fine aggregate and coarse aggregate, and the fine powder produced as a by-product is recovered. This fine powder is a fine powder in a state where carbonation has not progressed (hereinafter referred to as uncarbonated waste concrete fine powder). On the other hand, when fine particles are crushed and ground to produce a regenerated fine aggregate and the fine powder is collected, fine powder in which carbonation has progressed (hereinafter referred to as carbonated waste concrete fine powder) can be obtained.
未炭酸化廃コンクリート微粉末は、従来のセメント焼成の際の原料として用いる石灰石と異なり、すでに脱炭酸しているため、二酸化炭素排出を抑制することができるという新規な効果を期待できる。一方、炭酸化廃コンクリート微粉末は、ポゾラン反応性を有し、普通ポルトランドセメント等の従来セメントと混合することで強度発現に寄与し、ともに環境配慮型の再利用方法につながる。 Unlike the limestone used as a raw material for conventional cement firing, the uncarbonated waste concrete fine powder has already been decarboxylated, and therefore, a novel effect that carbon dioxide emission can be suppressed can be expected. On the other hand, carbonized waste concrete fine powder has pozzolanic reactivity, and contributes to strength development by mixing with conventional cement such as ordinary Portland cement, both of which lead to environmentally friendly recycling methods.
［回収方法の具体的説明］
図１は、本発明の廃コンクリート微粉末の回収方法における、各手順を示したフローチャートである。通常、鉄筋コンクリート建物を解体して発生したコンクリート塊は、前処理により、付着していた鉄筋と分離する際に小割りされ、およそ４００〜２００mm大の当初寸法のコンクリート塊として中間処理工場等に搬入され、所定期間保管される場合が多い。そして中間処理工場で、一次破砕として、当初寸法から約１５０mm大となるように粗破砕される。一次破砕機としてはジョークラッシャ等が用いられる。このときのコンクリート塊は保管状況、保管期間によって表面に炭酸化の進行が見られることが予想されるが、コンクリート塊の全体の大きさに比べ、表面積が小さいため、本発明の分離回収においては炭酸化した表面部分の材料変化は無視できる。
[Specific description of collection method]
FIG. 1 is a flowchart showing each procedure in the method for recovering fine waste concrete powder of the present invention. Normally, the concrete lumps generated by dismantling reinforced concrete buildings are subdivided when separated from the attached reinforcing bars by pretreatment, and delivered to intermediate processing factories as concrete lumps with an initial size of approximately 400 to 200 mm. Are often stored for a predetermined period. Then, in the intermediate processing plant, as the primary crushing, it is roughly crushed so as to be about 150 mm larger than the initial size. A jaw crusher or the like is used as the primary crusher. The concrete block at this time is expected to show carbonation on the surface depending on the storage status and storage period, but since the surface area is small compared to the overall size of the concrete block, in the separation and recovery of the present invention Material changes in the carbonated surface are negligible.
ここで、発明者の研究結果（非特許文献２参照）によれば粒径５mmふるい通過分を境として炭酸化の進行の度合いに差が認められていたが、コンクリート塊が水分を含んでいる場合のふるい作業性を考慮して、ふるい目５mmより粗いふるい目１０mmによる１次ふるい分けを行う。 Here, according to the research result of the inventor (see Non-Patent Document 2), a difference was recognized in the degree of progress of carbonation at the passage of the sieve having a particle size of 5 mm, but the concrete lump contains moisture. In consideration of the sieving workability of the case, primary sieving is performed with a 10 mm coarser screen than the 5 mm screen.
図１において、１０mmふるい残留分（粒径＞１０mm）は、その後、２次破砕、磨砕、分級を行って、再生粗骨材、再生細骨材、廃コンクリート微粉末とに分離して回収する。このとき、２次破砕、磨砕工程ではインパクトクラッシャ、各種公知の磨砕機を用いて再生骨材を製造し、分級機を経て所定規格の再生骨材（再生粗骨材、再生細骨材）とする。 In Fig. 1, the 10mm sieve residue (particle size> 10mm) is then recovered by separating it into recycled coarse aggregate, recycled fine aggregate and waste concrete fine powder by secondary crushing, grinding and classification. To do. At this time, in the secondary crushing and grinding processes, reclaimed aggregates are manufactured using impact crushers and various known grinders, and then passed through a classifier to recycle aggregates of a predetermined standard (recycled coarse aggregates and regenerated fine aggregates). And
このとき副次発生する未炭酸化廃コンクリート微粉末（脱炭酸セメント原料）は、セメント水和物であるＣａ(ＯＨ）2、Ｃ−Ｓ−Ｈ等を含むため、これらを所定の割合で混合してセメントクリンカーを焼成することで、資源の循環型再利用を図ることができる。 The uncarbonated waste concrete fine powder (decarbonated cement raw material) generated at this time contains Ca (OH) 2 , C—S—H, etc., which are cement hydrates, so these are mixed at a predetermined ratio. Then, by recycling the cement clinker, it is possible to recycle resources.
セメントクリンカーを焼成する際に、本発明の手順により分離回収された未炭酸化廃コンクリート微粉末を、すでに脱炭酸したカルシウム源として利用できるため、石灰石を用いる従来のセメント製造の場合に比べ、二酸化炭素排出抑制に寄与するという効果も期待できる。 When calcining the cement clinker, the uncarbonated waste concrete fine powder separated and recovered by the procedure of the present invention can be used as a source of calcium that has already been decarboxylated, and therefore, compared with the case of conventional cement production using limestone. The effect of contributing to carbon emission control can also be expected.
一方、１０mmふるい通過分も、ふるい残留分と同様に、２次破砕、磨砕、分級を行って再生細骨材と廃コンクリート微粉末とに分離、回収する。そのとき副次発生する廃コンクリート微粉末は、１次ふるい分けでふるいを通過した、比較的表面積の大きい微粒分を磨砕した微粉末であるため、微粒分の表面は当初から炭酸化が進行した状態にあり、このため、この微粉末は上述したように炭酸化廃コンクリート微粉末として分離回収される。なお、必要に応じて２次破砕、磨砕、分級工程の前に加熱処理することで、微粉末分の炭酸化を促進させることも好ましい。 On the other hand, the passage through the 10 mm sieve is separated and recovered into recycled fine aggregate and waste concrete fine powder by secondary crushing, grinding and classification in the same way as the sieve residue. At this time, the waste concrete fine powder generated as a by-product is a fine powder obtained by grinding the fine particles having a relatively large surface area that passed through the sieve by primary sieving, so that the surface of the fine particles was carbonized from the beginning. Therefore, this fine powder is separated and recovered as carbonated waste concrete fine powder as described above. In addition, it is also preferable to promote carbonation of a fine powder by heat-processing before a secondary crushing, grinding | pulverization, and a classification process as needed.
なお、未炭酸化廃コンクリート微粉末、炭酸化廃コンクリート微粉末の状態は、ＴＧ−ＤＴＡ（熱分析）の結果から判断することができる。未炭酸化廃コンクリート微粉末の場合、Ｃａ(ＯＨ）2含有率は少なくとも３％以上、炭酸化廃コンクリート微粉末の場合、ＤＴＡにおいてＣａ(ＯＨ）2の吸熱ピークが認められないことが条件となる。 In addition, the state of uncarbonated waste concrete fine powder and carbonated waste concrete fine powder can be judged from the result of TG-DTA (thermal analysis). In the case of uncarbonated waste concrete fine powder, the Ca (OH) 2 content is at least 3% or more. In the case of carbonated waste concrete fine powder, the endothermic peak of Ca (OH) 2 is not observed in DTA. Become.
炭酸化廃コンクリート微粉末は、炭酸化が進行しているため、未炭酸化廃コンクリート微粉末と異なり、セメント原料自体として使用した場合、二酸化炭素を排出するが、従来成分のセメントクリンカーに、ポゾラン反応を有する混合材として添加することが可能である。このため、セメント配合時のセメント混合材や、セメント系固化材として地盤改良材として使用することが好ましい。 Carbonated waste concrete fine powder is carbonized, so unlike uncarbonated waste concrete fine powder, when used as cement raw material itself, it emits carbon dioxide. It can be added as a mixed material having a reaction. For this reason, it is preferable to use it as a ground improvement material as a cement mixed material at the time of cement mixing or as a cement-based solidifying material.
図２両図は、廃コンクリート微粉末の熱分析結果を示したグラフである。図２（ａ）は粒径０〜４０mmの廃コンクリートを原料とした再生微粉末の熱分析結果、図２（ｂ）は１０〜４０mmの廃コンクリートを原料とした再生微粉末の熱分析結果示している。図２（ａ）に示したように、０〜４０mmの廃コンクリートを原料とした場合、中性化が進行した結果、Ｃａ(ＯＨ）2はほとんど認められないが、１０〜４０mmを原料とした場合にはＣａ(ＯＨ）2が十分に残っていることがわかる。このことから粒径１０mm以下の細粒分における中性化速度は１０mm超の粗粒分の中性化速度に比べて著しく速いことが確認できた。この点をふまえ、本発明では１０mmふるい分けを分離工程として採用した。 2 and FIG. 2 are graphs showing the results of thermal analysis of waste concrete fine powder. Fig. 2 (a) shows the thermal analysis results of recycled fine powder made from waste concrete with a particle size of 0 to 40 mm, and Fig. 2 (b) shows the thermal analysis results of recycled fine powder made from 10 to 40 mm of waste concrete. ing. As shown in FIG. 2 (a), when waste concrete of 0 to 40 mm was used as a raw material, Ca (OH) 2 was hardly recognized as a result of progress of neutralization, but 10 to 40 mm was used as a raw material. In this case, it can be seen that sufficient Ca (OH) 2 remains. From this, it was confirmed that the neutralization rate of fine particles having a particle size of 10 mm or less was remarkably faster than the neutralization rate of coarse particles having a particle size of more than 10 mm. Based on this point, in the present invention, 10 mm sieving is adopted as the separation step.
なお、本発明は上述した実施例に限定されるものではなく、各請求項に示した範囲内での種々の変更が可能である。すなわち、請求項に示した範囲内で適宜変更した技術的手段を組み合わせて得られる実施形態も、本発明の技術的範囲に含まれる。 In addition, this invention is not limited to the Example mentioned above, A various change within the range shown to each claim is possible. In other words, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.
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| CN102847703A (en) * | 2012-09-17 | 2013-01-02 | 北京丰旭晟工程技术有限公司 | Method for producing clean recycled soil and recycled aggregate by using construction waste |
| CN104266907A (en) * | 2014-07-08 | 2015-01-07 | 北京东方建宇混凝土科学技术研究院有限公司 | Determination method for compression strength ratio of low-quality recycled fine aggregate mixed mortar |
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| CN108080399A (en) * | 2017-12-26 | 2018-05-29 | 中城绿建科技有限公司 | Building castoff recycling recycles disposal impurity-removing method |
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| CN102847703A (en) * | 2012-09-17 | 2013-01-02 | 北京丰旭晟工程技术有限公司 | Method for producing clean recycled soil and recycled aggregate by using construction waste |
| JP2015189617A (en) * | 2014-03-27 | 2015-11-02 | 学校法人 芝浦工業大学 | Method of determining whether or not recycled aggregate can be expected to show quality improvement effect due to adsorption of carbon dioxide |
| CN104266907A (en) * | 2014-07-08 | 2015-01-07 | 北京东方建宇混凝土科学技术研究院有限公司 | Determination method for compression strength ratio of low-quality recycled fine aggregate mixed mortar |
| CN104307842A (en) * | 2014-09-05 | 2015-01-28 | 张云轩 | Wet concrete recycling and screening machine with automatic sewage pumping and transporting function and application method thereof |
| CN105693124A (en) * | 2016-01-20 | 2016-06-22 | 山东大学 | Preparation method and application method of fine reclaimed aggregate for concrete internal curing |
| CN108080399A (en) * | 2017-12-26 | 2018-05-29 | 中城绿建科技有限公司 | Building castoff recycling recycles disposal impurity-removing method |
| CN108906846A (en) * | 2018-06-22 | 2018-11-30 | 四川先舟建设工程有限公司 | It is a kind of to live and construction refuse resource utilization process |
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