JP4796420B2 - Hydrated cured body having reinforcing bars excellent in neutralization resistance and salt damage resistance and method for producing the same - Google Patents
Hydrated cured body having reinforcing bars excellent in neutralization resistance and salt damage resistance and method for producing the same Download PDFInfo
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- 238000006386 neutralization reaction Methods 0.000 title claims description 36
- 230000003014 reinforcing effect Effects 0.000 title claims description 36
- 150000003839 salts Chemical class 0.000 title claims description 22
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 239000002893 slag Substances 0.000 claims description 64
- 239000010881 fly ash Substances 0.000 claims description 35
- 238000009628 steelmaking Methods 0.000 claims description 32
- 239000004568 cement Substances 0.000 claims description 25
- 239000011398 Portland cement Substances 0.000 claims description 24
- 239000000843 powder Substances 0.000 claims description 22
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 15
- 239000000920 calcium hydroxide Substances 0.000 claims description 15
- 235000011116 calcium hydroxide Nutrition 0.000 claims description 15
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 15
- 229910000831 Steel Inorganic materials 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 12
- 239000010959 steel Substances 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 9
- 229910000975 Carbon steel Inorganic materials 0.000 claims description 7
- 239000010962 carbon steel Substances 0.000 claims description 7
- 239000012535 impurity Substances 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- 229910052698 phosphorus Inorganic materials 0.000 claims description 6
- 229910052719 titanium Inorganic materials 0.000 claims description 6
- 229910052720 vanadium Inorganic materials 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 229910052717 sulfur Inorganic materials 0.000 claims description 4
- 239000004567 concrete Substances 0.000 description 29
- 238000012360 testing method Methods 0.000 description 25
- 230000000694 effects Effects 0.000 description 19
- 239000000463 material Substances 0.000 description 19
- 238000001723 curing Methods 0.000 description 14
- 239000002245 particle Substances 0.000 description 12
- 239000011400 blast furnace cement Substances 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 230000036571 hydration Effects 0.000 description 8
- 238000006703 hydration reaction Methods 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- 230000007797 corrosion Effects 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 239000003513 alkali Substances 0.000 description 5
- 239000011150 reinforced concrete Substances 0.000 description 5
- 229910052758 niobium Inorganic materials 0.000 description 4
- 229920006395 saturated elastomer Polymers 0.000 description 4
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- 239000011362 coarse particle Substances 0.000 description 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 3
- 238000004898 kneading Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000002956 ash Substances 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- KJFMBFZCATUALV-UHFFFAOYSA-N phenolphthalein Chemical compound C1=CC(O)=CC=C1C1(C=2C=CC(O)=CC=2)C2=CC=CC=C2C(=O)O1 KJFMBFZCATUALV-UHFFFAOYSA-N 0.000 description 2
- 239000002436 steel type Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005536 corrosion prevention Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- YXVFQADLFFNVDS-UHFFFAOYSA-N diammonium citrate Chemical compound [NH4+].[NH4+].[O-]C(=O)CC(O)(C(=O)O)CC([O-])=O YXVFQADLFFNVDS-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 238000009415 formwork Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 150000004677 hydrates Chemical class 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 210000003205 muscle Anatomy 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000000638 stimulation Effects 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
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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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
-
- 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
本発明は、乾湿が繰り返される海岸等の中性化と塩害が進みやすい環境下で用いる構造物での利用に好適な耐中性化性および耐塩害性に優れた鉄筋を有する水和硬化体およびその製造方法に関するものである。 The present invention is a hydrated and cured body having a reinforcing bar excellent in neutralization resistance and salt damage resistance suitable for use in a structure used in an environment where neutralization and salt damage are likely to proceed, such as coasts where dryness and humidity are repeated And a manufacturing method thereof .
鉄筋コンクリートは、コンクリート中のアルカリ成分によって鉄筋の表面に不動態皮膜が形成されるため鉄筋が防食され、長期に渡って強度と耐久性を発揮する構造部材である。したがって、コンクリートが中性化すると不動態皮膜が破壊され鉄筋が腐食し、構造物部材として機能しなくなる。 Reinforced concrete is a structural member that exhibits strength and durability over a long period of time because the passive component film is formed on the surface of the reinforcing bar by the alkali components in the concrete, thereby preventing corrosion of the reinforcing bar. Therefore, when the concrete is neutralized, the passive film is destroyed and the rebar is corroded, so that it does not function as a structural member.
近年は、コンクリートの骨材の入手事情が悪化し、例えば、アルカリ骨材反応を生じる可能性がある安山岩等を骨材として使用せざるを得ない場合がある。アルカリ骨材反応によりコンクリートにひび割れを生じた場合、コンクリートの中性化が急速に進行し、鉄筋が腐食する等の問題がある。また良質な骨材を使用したコンクリートの場合であっても、これを乾湿が繰り返される等の中性化が進みやすい環境下で使用した際には、コンクリートの中性化よって鉄筋表面の不動態皮膜が破壊されて鉄筋が腐食し、発生した錆に起因する体積膨張によってコンクリートが剥落する。当然のことながら、鉄筋と外界との間に存在するコンクリートの厚み（かぶり厚）を増大させることにより、中性化が鉄筋の表面に到達する時間を遅延させることができるが、コンクリートのかぶり厚の増大により構造物が大型化するためコストが増大するという問題がある。 In recent years, the availability of concrete aggregates has deteriorated, and for example, andesite that may cause an alkali aggregate reaction may be used as an aggregate. When cracks occur in the concrete due to the alkali aggregate reaction, there is a problem that the neutralization of the concrete proceeds rapidly and the reinforcing bars corrode. Even in the case of concrete using high-quality aggregates, if it is used in an environment where neutralization is likely to proceed, such as repeated drying and wetting, the neutralization of the concrete causes the passivation of the reinforcing bar surface. The coating is destroyed and the rebar is corroded, and the concrete is peeled off by volume expansion caused by the generated rust. Naturally, increasing the thickness of the concrete (cover thickness) between the reinforcing bar and the outside world can delay the time for neutralization to reach the surface of the reinforcing bar. There is a problem that the cost increases because the structure becomes larger due to the increase in the size of the structure.
上記のような鉄筋コンクリートの耐中性化性を向上する手段としては、一般に水セメント比を小さくする方法が知られている
一方、製鋼スラグと高炉スラグ微粉末とを主原料とし、コンクリートの代替が可能な水和硬化体が特許文献１及び非特許文献１に開示されている。
As a means of improving the neutralization resistance of reinforced concrete as described above, a method of reducing the water-cement ratio is generally known. On the other hand, steelmaking slag and ground granulated blast furnace slag are the main raw materials, and concrete replacement is possible. Possible hydrated cured products are disclosed in Patent Document 1 and Non-Patent Document 1.
これらの水和硬化体をコンクリートの代替として用いることで、製鉄所で大量に発生するスラグを有効利用することができる。
しかし、鉄筋コンクリートの耐中性化性を向上させるために水セメント比を小さくする方法は、アルカリ骨材反応を生じることがない良質な骨材を用いたときは有効であるが、アルカリ骨材反応を生じる骨材を用いた場合は効果がない。また、水セメント比を小さくすると高コストとなるばかりでなく、コンクリートの自己収縮が大きくなるという弊害を生じる。 However, the method of reducing the water-cement ratio in order to improve the neutralization resistance of reinforced concrete is effective when using high-quality aggregates that do not cause alkali-aggregate reaction, but alkali-aggregate reaction. There is no effect when using aggregates that cause Moreover, if the water-cement ratio is reduced, not only the cost is increased, but also the self-shrinkage of the concrete is increased.
一方、上記の特許文献１、非特許文献１の水和硬化体をコンクリート代替として用いた場合の耐中性化性については、特許文献１に開示された水和硬化体は用途を路盤材、建築・土木材等としている程度で不明瞭であり、非特許文献１に開示された水和硬化体は、対象を鉄筋を含有しない無筋コンクリート代替に限定しているため、どちらについても性能自体が不明である。そこで、これらの水和硬化体の耐中性化性を本発明者らが調べたところ、極めてばらつきが大きく、鉄筋コンクリート代替として安定して使用することが困難であることがわかった。 On the other hand, regarding the neutralization resistance when the hydrated cured body of Patent Document 1 and Non-Patent Document 1 is used as a concrete substitute, the hydrated cured body disclosed in Patent Document 1 is used for roadbed materials, The hydration hardened body disclosed in Non-Patent Document 1 is unclear to the extent that it is used for construction and earthwork, etc., and the target is limited to the replacement of unreinforced concrete that does not contain reinforcing bars. Is unknown. Then, when the present inventors investigated the neutralization resistance of these hydrated cured bodies, it was found that the dispersion was extremely large and it was difficult to stably use as a substitute for reinforced concrete.
このように従来の技術を用いては、コンクリートや製鋼スラグと高炉スラグ微粉末等を材料とした水和硬化体の中性化を抑止して鉄筋の腐食を防止することは限界がある。 As described above, there is a limit to prevent corrosion of reinforcing bars by suppressing neutralization of a hydrated and hardened body made of concrete, steelmaking slag, blast furnace slag fine powder, or the like using conventional techniques.
したがって本発明の目的は、このような従来技術の課題を解決し、中性化が進みやすいような環境条件においても長期の耐久性を有する構造物部材とすることができる耐中性化性および耐塩害性に優れた鉄筋を有する水和硬化体およびその製造方法を提供することにある。 Therefore, the object of the present invention is to solve the problems of the prior art, and to make the structure member having long-term durability even under environmental conditions where neutralization is likely to proceed, An object of the present invention is to provide a hydrated cured product having a reinforcing bar excellent in salt damage resistance and a method for producing the same.
このような課題を解決するための本発明の特徴は以下の通りである。
（１）鉄筋を内部に有する水和硬化体が、少なくとも、ポルトランドセメント、ＪＩＳ Ｒ５２１３「フライアッシュセメント」に適合するＢ種のフライアッシュセメント、消石灰の中から選んだ１種または２種以上と、ＣａＯ／ＳｉＯ2が質量比で１．５未満またはＣａＯ濃度が２５質量％未満の製鋼スラグと、高炉スラグ微粉末とフライアッシュとを含有し、「ポルトランドセメント（ｋｇ／ｍ3）＋フライアッシュセメント（ｋｇ／ｍ3）×０．８５＋消石灰（ｋｇ／ｍ3）」が５５ｋｇ／ｍ3以上であり、さらに前記鉄筋が質量％でＣ：0.001〜0.025％、Ｓｉ：0.60％以下、Ｍｎ：0.10〜3.00％、Ｓ：0.01％以下、Ａｌ：0.10％以下、Ｂ：0.0001〜0.0050%を含有し、Ｐ：0.005〜0.030％、Ｎｉ：0.1〜6.0％、Ｃｕ：0.1〜1.5％、Ｍｏ：0.005〜0.5％の中から選ばれる１種または２種以上を含有し、残部がＦｅおよび不可避的不純物からなる耐候性を有する炭素鋼であり、製鋼スラグの含有量が２２３９ｋｇ／ｍ 3 以上であり、前記混合物中における高炉スラグ微粉末の含有量が１００〜６００ｋｇ／ｍ 3 であることを特徴とする耐中性化性および耐塩害性に優れた鉄筋を有する水和硬化体。
（２）鉄筋が、質量％で、さらに、Ｎｂ：0.005〜0.20％、Ｖ：0.005〜0.20％、Ｔｉ：0.005〜0.20％、ＲＥＭ：0.02％以下の内から選ばれる１種または２種以上を含有する。
（３）耐中性化性および耐塩害性に優れた鉄筋を有する水和硬化体の製造方法であって、鉄筋を内部に有する水和硬化体が、「ポルトランドセメント（ｋｇ／ｍ3）＋フライアッシュセメント（ｋｇ／ｍ3）×０．８５＋消石灰（ｋｇ／ｍ3）」が５５ｋｇ／ｍ3以上になるように、少なくとも、ポルトランドセメント、ＪＩＳ Ｒ５２１３「フライアッシュセメント」に適合するＢ種のフライアッシュセメント、消石灰の中から選んだ１種または２種以上と、ＣａＯ／ＳｉＯ2が質量比で１．５未満またはＣａＯ濃度が２５質量％未満の製鋼スラグと、高炉スラグ微粉末とフライアッシュとを水と混合し、得られた混合物を硬化するステップを含み、前記鉄筋が質量％でＣ：0.001〜0.025％、Ｓｉ：0.60％以下、Ｍｎ：0.10〜3.00％、Ｓ：0.01％以下、Ａｌ：0.10％以下、Ｂ：0.0001〜0.0050%を含有し、Ｐ：0.005〜0.030％、Ｎｉ：0.1〜6.0％、Ｃｕ：0.1〜1.5％、Ｍｏ：0.005〜0.5％の中から選ばれる１種または２種以上を含有し、残部がＦｅおよび不可避的不純物からなる耐候性を有する炭素鋼であり、製鋼スラグの含有量が２２３９ｋｇ／ｍ 3 以上であり、前記混合物中における高炉スラグ微粉末の含有量が１００〜６００ｋｇ／ｍ 3 であることを特徴とする耐中性化性および耐塩害性に優れた鉄筋を有する水和硬化体の製造方法。
The features of the present invention for solving such problems are as follows.
(1) A hydrated cured body having reinforcing bars inside is at least one selected from Portland cement , B type fly ash cement suitable for JIS R5213 “fly ash cement” , slaked lime, Contains steelmaking slag with a CaO / SiO 2 ratio of less than 1.5 or a CaO concentration of less than 25% by mass, blast furnace slag fine powder and fly ash , “Portland cement (kg / m 3 ) + fly ash cement” (Kg / m 3 ) × 0.85 + slaked lime (kg / m 3 ) ”is 55 kg / m 3 or more, and the rebar is in mass% C: 0.001 to 0.025%, Si: 0.60% or less, Mn: 0.10 -3.00%, S: 0.01% or less, Al: 0.10% or less, B: 0.0001-0.0050%, P: 0.005-0.030%, Ni: 0.1-6.0%, Cu: 0.1-1.5%, Mo: 0.005 Choose from ~ 0.5% Contain one or two or more that the balance Ri Ah of carbon steel having a weather resistance of Fe and unavoidable impurities, the content of steel slag is at 2239kg / m 3 or more, blast furnace slag in the mixture耐中of resistance and salt damage excellent in hydration cured product having a reinforcing bar, wherein the amount of the fine powder is 100~600kg / m 3.
(2) Reinforcing bars are in mass%, and Nb: 0.005-0.20%, V: 0.005-0.20%, Ti: 0.005-0.20%, REM: 0.02% or less contains.
(3) A method for producing a hydrated and cured product having a reinforcing bar excellent in neutralization resistance and salt damage resistance, wherein the hydrated and cured product having a reinforcing bar inside is “Portland cement (kg / m 3 ) + At least B type suitable for Portland cement , JIS R5213 “fly ash cement” so that “ fly ash cement (kg / m 3 ) × 0.85 + slaked lime (kg / m 3 )” is 55 kg / m 3 or more . One or more selected from fly ash cement and slaked lime, steelmaking slag with a CaO / SiO 2 mass ratio of less than 1.5 or a CaO concentration of less than 25% by mass, blast furnace slag fine powder and fly ash And the step of curing the resulting mixture, wherein the rebar is in mass% C: 0.001 to 0.025%, Si: 0.60% or less, Mn: 0.10 to 3.00%, S: 0.01% or less, Al: 0.10% or less, B: 0.0001 to 0.0050%, P: 0.005 to 0.030%, Ni: 0.1 to 6.0%, Cu: 0.1 to 1.5%, Mo: 0.005 to 0.5% or comprise two or more, the balance Ri Ah of carbon steel having a weather resistance of Fe and unavoidable impurities, the content of steel slag is at 2239kg / m 3 or more, the ground granulated blast furnace slag in the mixture method for producing a hydrated cured product having耐中resistance resistance and salt damage excellent in reinforcing bars, wherein the content of 100~600kg / m 3.
本発明によれば耐中性化性と耐塩害性に優れることから、鉄筋に対する防食性に優れた水和硬化体が得られる。このため、中性化により従来の鉄筋コンクリートが短期間で崩壊するような環境下においても、長期間の使用が可能な構造物を提供できる。 According to the present invention, since it is excellent in neutralization resistance and salt damage resistance, a hydrated cured product having excellent anticorrosive properties against reinforcing steel can be obtained. For this reason, the structure which can be used for a long period of time can be provided even in the environment where the conventional reinforced concrete collapses in a short period of time by neutralization.
本発明では、水和硬化体の材料を最適化することにより、従来のコンクリートや製鋼スラグと高炉スラグ微粉末等を材料とした水和硬化体よりも耐中性化性に優れた水和硬化体が得られ、これを所定の成分を有する耐候性を有する炭素鋼からなる鉄筋と組み合わせることで、高塩分濃度を含有し乾湿が繰り返される中性化および塩害の進みやすい環境下においても長期の耐久性を有する構造物部材として使用できることを見出し、本発明を完成した。 In the present invention, by optimizing the material of the hydrated hardened body, the hydration hardening having better neutralization resistance than conventional hydrated hardened bodies made of concrete, steelmaking slag and blast furnace slag fine powder, etc. By combining this with a reinforcing steel bar composed of weather-resistant carbon steel having a predetermined component, it can be used for a long period of time even in an environment where neutralization and salt damage are likely to occur. The present invention has been completed by finding that it can be used as a structural member having durability.
まず水和硬化体を構成する材料について説明する。 First, materials constituting the hydrated cured body will be described.
なお、本発明において、水和硬化体における（水和硬化体中の）含有量（配合量）とは、水和硬化体の配合原料となる各材料（混練用の水や混和剤なども含む）を混合した混合物中における含有量を意味する。本発明における水和硬化体は、配合原料となる材料を混合して形成した混合物を硬化させたものである。 In the present invention, the content (in the hydrated cured body) (in the hydrated cured body) of the hydrated cured body includes each material (including kneading water and admixture) that is a raw material for blending the hydrated cured body. ) In the mixed mixture. The hydrated cured product in the present invention is obtained by curing a mixture formed by mixing materials to be blended raw materials.
本発明の水和硬化体は、製鋼スラグと、高炉スラグ微粉末と、さらに、ポルトランドセメント、高炉セメント、フライアッシュセメント、消石灰の中から選んだ１種または２種以上とを含有する。 The hydrated hardened body of the present invention contains steelmaking slag, blast furnace slag fine powder, and one or more selected from Portland cement, blast furnace cement, fly ash cement, and slaked lime.
水和硬化体の材料のうち、製鋼スラグは、骨材および結合材、さらに水和硬化体の中性化抑止材として作用する。骨材として作用させるための製鋼スラグの粒度分布は、コンクリート用の細骨材や粗骨材に相当するような粒度とし、粒径が０．０７５ｍｍ以上程度、また最大粒径が４０ｍｍ以下程度とすることが好ましい。また、結合材として作用させるための製鋼スラグは微粉であることが好ましく、粒径が０．１５ｍｍ未満程度であることが好ましい。したがって、結合材としての粒径と骨材としての粒径をそれぞれ満足するスラグ粒子が含まれている適当な粒度分布を有する製鋼スラグ（例えば、或る条件で粉砕処理した製鋼スラグやその粉砕処理後に篩分した製鋼スラグ）を使用することが望ましい。中性化抑止材として作用させるための製鋼スラグは、ＣａＯ／ＳｉＯ2が質量比で１．５以上、またはＣａＯ濃度が２５質量％以上であることが好ましい。ＣａＯ／ＳｉＯ2が質量比で１．５以上、またはＣａＯ濃度が２５質量％以上の製鋼スラグは、製鋼スラグ中のＣａＯ成分が長期間にわたり水和硬化体中に含まれる水に溶解し、水和硬化体を弱アルカリ性に保ち、中性化を抑止する。より好ましくは、ＣａＯ／ＳｉＯ2が質量比で２．０以上、またはＣａＯ濃度が３０質量％以上である。一般にＣａＯ／ＳｉＯ2、ＣａＯ濃度が高くなると製鋼スラグ中の遊離ＣａＯ（ｆｒｅｅ−ＣａＯ）による水和膨張性が大きくなるが、水和硬化体の膨張安定性が確保されれば問題がないことから、これらの上限値は特に規定しない。 Among the materials of the hydrated hardened body, the steelmaking slag acts as an aggregate and a binder, and further as a neutralization inhibitor for the hydrated hardened body. The particle size distribution of the steelmaking slag for acting as an aggregate is a particle size corresponding to fine aggregate or coarse aggregate for concrete, the particle size is about 0.075 mm or more, and the maximum particle size is about 40 mm or less. It is preferable to do. Moreover, it is preferable that the steelmaking slag for making it act as a binder is a fine powder, and it is preferable that a particle size is less than about 0.15 mm. Accordingly, a steelmaking slag having an appropriate particle size distribution containing slag particles satisfying the particle size as a binder and the particle size as an aggregate (for example, steelmaking slag pulverized under a certain condition and its pulverization treatment). It is desirable to use steelmaking slag that is sieved later. The steelmaking slag for acting as a neutralization inhibiting material preferably has a CaO / SiO 2 ratio of 1.5 or more, or a CaO concentration of 25% by mass or more. CaO / SiO 2 is in a weight ratio of 1.5 or more, or CaO concentration of 25 mass% or more steel slag is dissolved in water CaO component in the steelmaking slag is contained in the hydrated cured body over a long period of time, water Keep the Japanese cured body weakly alkaline and suppress neutralization. More preferably, CaO / SiO 2 is 2.0 or more by mass ratio, or the CaO concentration is 30% by mass or more. Generally, when the CaO / SiO 2 and CaO concentrations are increased, the hydration expansion due to free CaO (free-CaO) in the steelmaking slag increases, but there is no problem if the expansion stability of the hydrated cured body is ensured. These upper limits are not specified.
また、製鋼スラグは通常の砂利等の骨材と異なりアルカリ骨材反応を起こさないため、水和硬化体そのものの耐久性が優れるだけでなく、アルカリ骨材反応に起因するひび割れの発生も抑制できるので、ひび割れを介した中性化が起こらず、水和硬化体中の鉄筋の防食の観点からも好ましい。 In addition, steelmaking slag does not cause an alkali-aggregate reaction unlike ordinary gravel aggregates, so that not only the durability of the hydrated hardened body itself is excellent, but also the occurrence of cracks due to the alkali-aggregate reaction can be suppressed. Therefore, neutralization through cracks does not occur, which is preferable from the viewpoint of corrosion prevention of reinforcing steel in the hydrated cured body.
水和硬化体の材料として高炉スラグ微粉末を用いるのは、潜在水硬性を有する高炉スラグ微粉末が製鋼スラグによりアルカリ刺激を受け効率的に水和反応するためだけでなく、従来のコンクリートよりも硬化物が緻密な組織を有するため、水和硬化体の中性化の原因となる二酸化炭素の透過を著しく抑制できるからである。また、高炉スラグ微粉末と製鋼スラグ中の遊離ＣａＯ（ｆｒｅｅ−ＣａＯ）が反応し、製鋼スラグの水和膨張を抑制するためである。高炉スラグ微粉末としてはＪＩＳ Ａ ６２０６「コンクリート用高炉スラグ微粉末」を特に好ましく用いることができる。 The reason why blast furnace slag fine powder is used as a material for the hydrated hardened body is not only because the blast furnace slag fine powder having latent hydraulic properties is subjected to alkali stimulation by steelmaking slag and efficiently hydrates but also more than conventional concrete. This is because, since the cured product has a dense structure, the permeation of carbon dioxide that causes neutralization of the hydrated cured product can be remarkably suppressed. Moreover, it is because the free blast furnace slag fine powder and free CaO (free-CaO) in the steelmaking slag react to suppress the hydration expansion of the steelmaking slag. As the blast furnace slag fine powder, JIS A 6206 “Blast furnace slag fine powder for concrete” can be particularly preferably used.
水和硬化体の材料として、ポルトランドセメント、高炉セメント、フライアッシュセメント、消石灰の中から選んだ１種または２種以上を用いるのは、これらの材料を混合することで、水和硬化体の内部をアルカリ性に保つためである。なお、本発明におけるポルトランドセメントとは、ＪＩＳ Ｒ ５２１０「ポルトランドセメント」に記載されている、普通ポルトランドセメント、早強ポルトランドセメント、超早強ポルトランドセメント、中庸熱ポルトランドセメント、低熱ポルトランドセメント、耐硫酸塩ポルトランドセメントのことである。また、高炉セメントとは、ＪＩＳ Ｒ ５２１１「高炉セメント」に記載されているＡ種、Ｂ種、Ｃ種のことである。また、フライアッシュセメントとは、ＪＩＳ Ｒ ５２１３「フライアッシュセメント」に記載のＡ種、Ｂ種、Ｃ種のことである。 One or more types selected from Portland cement, blast furnace cement, fly ash cement, and slaked lime are used as the material of the hydrated cured body. Is to keep the alkalinity. The Portland cement in the present invention is described in JIS R 5210 “Portland cement”, ordinary Portland cement, early-strength Portland cement, super-early-strength Portland cement, moderately hot Portland cement, low heat Portland cement, sulfate resistant salt Portland cement. Further, the blast furnace cement is A type, B type or C type described in JIS R 5211 “Blast furnace cement”. Moreover, fly ash cement is A class, B class, and C class as described in JIS R 5213 “fly ash cement”.
本発明ではさらに、ポルトランドセメント、高炉セメント、フライアッシュセメント、消石灰の水和硬化体中の配合量を、「ポルトランドセメント（ｋｇ／ｍ3）＋高炉セメント（ｋｇ／ｍ3）×０．６＋フライアッシュセメント（ｋｇ／ｍ3）×０．８５＋消石灰（ｋｇ／ｍ3）」で５５ｋｇ／ｍ3以上とする。５５ｋｇ／ｍ3以上となるように多量に含有させることにより、ＣａＯ／ＳｉＯ2が質量比で１．５未満またはＣａＯ濃度が２５質量％未満の製鋼スラグを用いた水和硬化体の場合でも、内部を長期間にわたりアルカリ性に保つことができる。この値は、好ましくは７０ｋｇ／ｍ3以上である。この値の上限値は特に設定しないが、１５０ｋｇ／ｍ3を超えて配合しても耐中性化性効果の向上はほとんど無い。 In the present invention, the blending amount of Portland cement, blast furnace cement, fly ash cement, and slaked lime in the hydrated hardened body is expressed as “Portland cement (kg / m 3 ) + blast furnace cement (kg / m 3 ) × 0.6 + fly. Ash cement (kg / m 3 ) × 0.85 + slaked lime (kg / m 3 ) ”is set to 55 kg / m 3 or more. By large amount is contained so that 55 kg / m 3 or more, even if 1.5 or below CaO concentration CaO / SiO 2 mass ratio of hydrated hardened body using steel slag of less than 25 wt%, The inside can be kept alkaline for a long time. This value is preferably 70 kg / m 3 or more. The upper limit of this value is not particularly set, but even if it exceeds 150 kg / m 3 , there is almost no improvement in the neutralization resistance effect.
高炉スラグ微粉末の水和硬化体中の配合量は、１００〜６００ｋｇ／ｍ3であることが好ましい。１００ｋｇ／ｍ3未満ではコンクリート代替として必要な１８Ｎ／ｍｍ2以上の圧縮強度が得られない場合があり、６００ｋｇ／ｍ3を超えると強度の増加はほとんど無く不経済となるためである。高炉スラグ微粉末のより好ましい配合量は、２００〜４００ｋｇ／ｍ3である。 The blending amount of the blast furnace slag fine powder in the hydrated cured product is preferably 100 to 600 kg / m 3 . If it is less than 100 kg / m 3 , the compressive strength of 18 N / mm 2 or more necessary as a concrete substitute may not be obtained, and if it exceeds 600 kg / m 3 , there is almost no increase in strength and it becomes uneconomical. A more preferable blending amount of the blast furnace slag fine powder is 200 to 400 kg / m 3 .
水和硬化体は、さらにフライアッシュを含有することが好ましい。水和硬化体の材料としてフライアッシュを用いるのは、製鋼スラグ中のＣａ成分とフライアッシュが効率的に反応することによりフライアッシュのポゾラン反応が進むためである。また、フライアッシュと製鋼スラグ中の遊離ＣａＯが反応し、製鋼スラグの水和膨張を抑制するためである。さらに、フライアッシュの適量の配合でワーカビリティを向上させる効果もある。フライアッシュはＪＩＳ Ａ ６２０１「コンクリート用フライアッシュ」を用いることが好ましいが、原粉および加圧流動床灰の使用等も可能である。 The hydrated cured body preferably further contains fly ash. The reason why fly ash is used as the material of the hydrated and cured body is that the Ca component in the steelmaking slag and the fly ash react efficiently so that the pozzolanic reaction of fly ash proceeds. Moreover, it is for the free CaO in fly ash and steelmaking slag to react, and to suppress the hydration expansion of steelmaking slag. Furthermore, there is an effect of improving workability by blending an appropriate amount of fly ash. The fly ash is preferably JIS A 6201 “Fly Ash for Concrete”, but it is also possible to use raw powder and pressurized fluidized bed ash.
フライアッシュの水和硬化体中の配合量は、特に限定しないが、５０〜３００ｋｇ／ｍ3であることが好ましい。５０ｋｇ／ｍ3未満では製鋼スラグの水和膨張を抑制する効果が低く、３００ｋｇ／ｍ3を超えると水を加えて練混ぜた後のフレッシュな状態の粘性が高くなり、ワーカビリティが悪化するため、また製鋼スラグの水和膨張を抑制する効果も変わらず不経済であるためである。 Although the compounding quantity in the hydrated hardening body of fly ash is not specifically limited, It is preferable that it is 50-300 kg / m < 3 >. If it is less than 50 kg / m 3 , the effect of suppressing the hydration expansion of steelmaking slag is low, and if it exceeds 300 kg / m 3 , the viscosity of the fresh state after adding water and kneading increases, and workability deteriorates. Moreover, it is because the effect which suppresses the hydration expansion of steelmaking slag is also uneconomical.
次に、本発明で用いる鉄筋について説明する。尚、無筋の水和硬化体は、耐中性化性が優れていない場合でも問題とはならない。 Next, the reinforcing bars used in the present invention will be described. In addition, the non-muscle hydrated cured product does not cause a problem even when the resistance to neutralization is not excellent.
鉄筋に用いる鋼材としては、質量％でＣ：０．００１〜０．０２５％、Ｓｉ：０．６０％以下、Ｍｎ：０．１０〜３．００％、Ｓ：０．０１％以下、Ａｌ：０．１０％以下、Ｂ：０．０００１〜０．００５０％を含有し、Ｐ：０．００５〜０．０３０％、Ｎｉ：０．１〜６．０％、Ｃｕ：０．１〜１．５％、Ｍｏ：０．００５〜０．５％の中から選ばれる１種以上を含有し、残部がＦｅおよび不可避的不純物から成る耐候性を有する炭素鋼を用いる。 As steel materials used for the reinforcing bars, C: 0.001 to 0.025%, Si: 0.60% or less, Mn: 0.10 to 3.00%, S: 0.01% or less, Al: 0.10% or less, B: 0.0001-0.0050%, P: 0.005-0.030%, Ni: 0.1-6.0%, Cu: 0.1-1. 5%, Mo: One or more selected from 0.005 to 0.5% is used, and a carbon steel having weather resistance, the balance of which consists of Fe and inevitable impurities, is used.
炭素鋼が質量％でさらに、Ｎｂ：０．００５〜０．２０％、Ｖ：０．００５〜０．２０％、Ｔｉ：０．００５〜０．２０％、ＲＥＭ：０．０２％以下の内から選ばれた１種または２種以上を含有することが好ましい。 Further, the carbon steel is in mass%, and Nb: 0.005 to 0.20%, V: 0.005 to 0.20%, Ti: 0.005 to 0.20%, REM: 0.02% or less It is preferable to contain 1 type, or 2 or more types selected from.
以下、各化学成分の限定理由について説明する。以下の説明において％で示す単位は全て質量％である。 Hereinafter, the reasons for limiting each chemical component will be described. In the following description, all units represented by% are mass%.
Ｃ：０．００１〜０.０２５％とする。
Ｃ量が減少すると、耐候性向上に有利である。０.０２５％を超えると、その効果は小さい。また、０．０２５％を超えると靭性、溶接性が劣化する。０．００１％未満であると、所望の強度を確保できない。そこで、０．００１〜０.０２５％に限定する。さらに好ましくは、０．００１〜０．０２％である。
C: 0.001 to 0.025%.
When the amount of C decreases, it is advantageous for improving the weather resistance. If it exceeds 0.025%, the effect is small. If it exceeds 0.025%, toughness and weldability deteriorate. If it is less than 0.001%, the desired strength cannot be ensured. Therefore, the content is limited to 0.001 to 0.025%. More preferably, it is 0.001 to 0.02%.
Ｓｉ：０.６０％以下とする。
Ｓｉは、脱酸剤として作用し、さらに鋼の強度を増加させる元素であるが、多量に含有すると靭性および溶接性を劣化させるため、０.６０％以下に限定する。なお、好ましくは０．１５〜０．５０％である。
Si: Set to 0.60% or less.
Si is an element that acts as a deoxidizer and further increases the strength of the steel, but if contained in a large amount, it deteriorates toughness and weldability, so it is limited to 0.60% or less. In addition, Preferably it is 0.15-0.50%.
Ｍｎ：０.１０〜３．００％とする。
Ｍｎは鋼の強度および靭性の増加に大きく寄与する元素であり、所望の強度を確保するために０．１０％以上添加するが、３.００％を超えて多量に含有すると靭性、溶接性に悪影響を及ぼすため、０.１０〜３．００％の範囲に限定する。なお、寒冷地等で高靭性が要求される場合には、低Ｍｎ化が効果的である。
Mn: 0.10 to 3.00%.
Mn is an element that greatly contributes to an increase in the strength and toughness of the steel, and is added in an amount of 0.10% or more in order to ensure the desired strength, but if contained in a large amount exceeding 3.00%, the toughness and weldability are improved. In order to adversely affect, it is limited to the range of 0.10 to 3.00%. In addition, when high toughness is required in cold districts or the like, lowering Mn is effective.
Ｓ：０．０１％以下とする。
Ｓは耐候性を劣化させ、さらに溶接性、靭性を劣化させるため、０．０１％以下に限定する。
S: 0.01% or less.
S degrades the weather resistance and further degrades the weldability and toughness, so it is limited to 0.01% or less.
Ａｌ：０．１０％以下とする。
Ａｌは脱酸剤として添加するが０．１０％を超えて含有すると、溶接性に悪影響を及ぼすため、０.１０％を上限とする。
Al: 0.10% or less.
Al is added as a deoxidizer, but if it exceeds 0.10%, the weldability is adversely affected, so 0.10% is made the upper limit.
Ｂ：０．０００１〜０．００５０％とする。
Ｂは焼入れ性を増加させ、さらに耐候性を向上させる元素であり、重要な元素である。このような効果は０．０００１％以上の含有で認められるが、０．００５０％を超えて含有しても含有量に見合う効果を期待できない。このため、Ｂは０．０００１〜０．００５０％の範囲に限定する。より好ましくは０．０００３〜０．００３０％の範囲である。なお、Ｂの耐候性向上の詳細な機構は明確ではないが、次のように考えられる。錆層中に付着した塩分は、降雨、結露水（あるいは潮解）によってイオン化し、Ｃｌイオンとなり錆層中のｐＨを低下させる。このｐＨの低下は鉄のアノード溶解を促進し、耐候性を劣化させる。Ｂはこの塩素によるｐＨ低下を防ぐ作用を有していると考えられる。
B: Set to 0.0001 to 0.0050%.
B is an element that increases the hardenability and further improves the weather resistance, and is an important element. Such an effect is recognized when the content is 0.0001% or more, but even if the content exceeds 0.0050%, an effect commensurate with the content cannot be expected. For this reason, B is limited to 0.0001 to 0.0050% of range. More preferably, it is 0.0003 to 0.0030% of range. The detailed mechanism for improving the weather resistance of B is not clear, but is considered as follows. The salt adhering to the rust layer is ionized by rainfall and dew condensation water (or deliquescence) to become Cl ions and lower the pH in the rust layer. This decrease in pH promotes anodic dissolution of iron and degrades weather resistance. B is considered to have an action of preventing pH reduction due to chlorine.
Ｐ、Ｎｉ、Ｃｕ、Ｍｏの中から選ばれる１種または２種以上を含有する。 Contains one or more selected from P, Ni, Cu, and Mo.
Ｐ：０．００５〜０．０３０％とする。
Ｐは耐候性を向上させる元素であるが、０．００５％未満の添加では耐候性向上の効果がない。しかし、０．０３０％を超える添加では溶接性が劣化する。このため、Ｐは０．００５〜０．０３０％の範囲に限定する。
P: Set to 0.005 to 0.030%.
P is an element that improves the weather resistance, but addition of less than 0.005% has no effect of improving the weather resistance. However, when the content exceeds 0.030%, the weldability deteriorates. For this reason, P is limited to 0.005 to 0.030% of range.
Ｎｉ：０．１〜６．０％とする。
Ｎｉは耐候性を向上させるが、０．１％未満の含有ではその効果が少ない。一方、６．０％を超えて含有しても効果が飽和し含有量に見合う効果が認められず、経済的に不利となる。このため、Ｎｉは０．１〜６．０％の範囲とした。なお、塩分量が多い場合には、Ｎｉは多い方が好ましいが、経済性をも考慮すると、２．０〜３．５％の範囲が好ましく、２．５〜３．０％がより好ましい。
Ni: 0.1 to 6.0%.
Ni improves the weather resistance, but if it is less than 0.1%, its effect is small. On the other hand, even if the content exceeds 6.0%, the effect is saturated and an effect commensurate with the content is not recognized, which is economically disadvantageous. For this reason, Ni was taken as 0.1 to 6.0% of range. In addition, when there is much salt content, the one where Ni is more preferable is preferable, but when considering also economical efficiency, the range of 2.0 to 3.5% is preferable, and 2.5 to 3.0% is more preferable.
Ｃｕ：０．１〜１．５％とする。
Ｃｕは耐候性を向上させる。しかしＣｕ含有量が０．１％未満ではその効果が少なく、一方、１．５％を超えると熱間加工性を阻害するとともに、耐候性向上効果も飽和し経済的に不利となる。このため、Ｃｕ含有量は０．１〜１．５％の範囲に限定する。
Cu: 0.1 to 1.5%.
Cu improves the weather resistance. However, when the Cu content is less than 0.1%, the effect is small. On the other hand, when the Cu content exceeds 1.5%, hot workability is impaired and the weather resistance improvement effect is saturated, which is economically disadvantageous. For this reason, Cu content is limited to 0.1 to 1.5% of range.
Ｍｏ：０．００５〜０．５％とする。
Ｍｏは耐候性を向上させ、さらに強度を増加させるが、０．００５％未満の含有ではその効果が少ない。一方、０．５％を超えて含有しても効果が飽和し含有量に見合う効果が認められず、経済的に不利となる。このため、Ｍｏは０．００５〜０．５％の範囲とする。なお、靭性の観点から、０．００５〜０．３５％の範囲が好ましい。
Mo: 0.005 to 0.5%.
Mo improves the weather resistance and further increases the strength. However, if the content is less than 0.005%, the effect is small. On the other hand, if the content exceeds 0.5%, the effect is saturated and an effect commensurate with the content is not recognized, which is economically disadvantageous. For this reason, Mo is taken as 0.005 to 0.5% of range. In addition, from the viewpoint of toughness, the range of 0.005 to 0.35% is preferable.
さらに、Ｎｂ：０．００５〜０．２０％、Ｖ：０．００５〜０．２０％、Ｔｉ：０．００５〜０．２０％、ＲＥＭ：０．０２％以下の内から選ばれる１種または２種以上を含有することが好ましい。 Further, Nb: 0.005 to 0.20%, V: 0.005 to 0.20%, Ti: 0.005 to 0.20%, REM: one selected from 0.02% or less or It is preferable to contain 2 or more types.
Ｎｂ、Ｖ、Ｔｉは鋼材の強度を増加させる元素であり、いずれも０．００５％以上の含有で効果が認められるが、それぞれ０．２０％を超えて含有しても効果が飽和する。このため、Ｎｂ、Ｖ、Ｔｉはいずれも０．００５〜０．２０％とするのが好ましい。ＲＥＭは溶接性を向上させる作用を有し、必要に応じ添加できる。ＲＥＭは０．００１％以上の添加で効果が認められるが、多量の添加は鋼材の清浄度を劣化させるため、０．０２％を上限とする。 Nb, V, and Ti are elements that increase the strength of the steel material, and any of them is effective when contained in an amount of 0.005% or more. However, the effect is saturated even if the content exceeds 0.20%. For this reason, it is preferable that Nb, V, and Ti are all 0.005 to 0.20%. REM has the effect | action which improves weldability, and can be added as needed. REM is effective when added in an amount of 0.001% or more, but adding a large amount deteriorates the cleanliness of the steel material, so 0.02% is made the upper limit.
上記以外の残部はＦｅおよび不可避的不純物である。不可避的不純物として、Ｃｒ：０．０５％以下、Ｎ：０．０１０％以下、Ｏ：０．０１０％以下が許容できる。Ｃｒは耐候性を向上させる元素であると言われているが、効果があるのは塩分の少ない環境下における場合であり、本発明の水和硬化体を使用する海岸地帯のような塩分の多い環境下では逆に耐候性を劣化させる元素であり、本発明ではあえて添加しないが、０．０５％までは許容できる。 The balance other than the above is Fe and inevitable impurities. As unavoidable impurities, Cr: 0.05% or less, N: 0.010% or less, and O: 0.010% or less are acceptable. Although Cr is said to be an element that improves weather resistance, it is effective in an environment with a low salinity, and has a high salinity like a coastal area using the hydrated cured body of the present invention. In the environment, it is an element that deteriorates the weather resistance. In the present invention, it is not intentionally added, but 0.05% is acceptable.
上記の化学組成を有する鉄筋は、転炉、電気炉等通常公知の溶製方法で溶製され、連続鋳造法あるいは造塊法により鋼素材とし、加熱炉等で加熱され、あるいは加熱なしで直接、熱間圧延により所望の形状に圧延して製造する。溶製方法は、真空脱ガス製錬等を実施してもよい。 Reinforcing bars with the above chemical composition are melted by a generally known melting method such as a converter or electric furnace, made into a steel material by a continuous casting method or an ingot forming method, and heated in a heating furnace or directly without heating. It is manufactured by rolling into a desired shape by hot rolling. As the melting method, vacuum degassing smelting or the like may be performed.
水和硬化体は、上記の材料を配合して、水を加えて混練して、所定の型枠等に打ち込んで養生して製造する。打ち込みの際に鉄筋を配筋して、鉄筋を有する水和硬化体とする。 The hydrated cured body is produced by blending the above materials, adding water, kneading, and driving and curing in a predetermined formwork or the like. Reinforcing bars are placed during driving to obtain a hydrated hardened body having reinforcing bars.
水和硬化体の養生方法は、所定の強度が確保できれば、通常コンクリートにおいて用いられる水中養生、現場養生、蒸気養生等の何れの方法をも用いることができる。 As a curing method for the hydrated cured body, any method such as underwater curing, on-site curing, and steam curing that are usually used in concrete can be used as long as a predetermined strength can be secured.
製鋼スラグは表１に示す化学成分、物性値（最大粒径、粗粒率、細骨材率、表乾密度）のものを用いた（製鋼スラグＮｏ．Ａ、Ｂ）。粗粒率とはＪＩＳ Ａ ０２０３に記載の番号３１１５の粗粒率のことである。細骨材率とは全粒度の製鋼スラグ量に対する粒径５ｍｍ以下の製鋼スラグ量の絶対容積比を百分率で表した値である。 The steelmaking slags used were those having the chemical components and physical properties shown in Table 1 (maximum particle size, coarse particle ratio, fine aggregate ratio, surface dry density) (steelmaking slag Nos. A and B). The coarse particle ratio is the coarse particle ratio of No. 3115 described in JIS A 0203. The fine aggregate rate is a value representing the absolute volume ratio of the amount of steelmaking slag having a particle size of 5 mm or less with respect to the amount of steelmaking slag of all particle sizes as a percentage.
高炉スラグ微粉末はＪＩＳ Ａ ６２０６「コンクリート用高炉スラグ微粉末」における高炉スラグ微粉末４０００を、フライアッシュはＪＩＳ Ａ ６２０１「コンクリート用フライアッシュ」におけるII種を使用した。ポルトランドセメントは、ＪＩＳ Ｒ ５２０１「ポルトランドセメント」に適合する普通ポルトランドセメントを用いた。高炉セメントは、ＪＩＳ Ｒ ５２１１「高炉セメント」に適合するＢ種を用いた。フライアッシュセメントは、ＪＩＳ Ｒ ５２１３「フライアッシュセメント」に適合するＢ種を用いた。消石灰は、ＪＩＳ Ｒ ９００１に適合する工業用消石灰・特号を使用した。混和剤は、ＪＩＳ Ａ ６２０４に適合するポリカルボン酸系の高性能ＡＥ減水剤を使用した。 Blast furnace slag fine powder used was blast furnace slag fine powder 4000 in JIS A 6206 “Blast furnace slag fine powder for concrete”, and fly ash used type II in JIS A 6201 “Fly ash for concrete”. As the Portland cement, ordinary Portland cement conforming to JIS R 5201 “Portland cement” was used. As the blast furnace cement, type B suitable for JIS R 5211 “blast furnace cement” was used. As the fly ash cement, type B conforming to JIS R 5213 “fly ash cement” was used. As the slaked lime, industrial slaked lime / special name conforming to JIS R 9001 was used. As the admixture, a polycarboxylic acid-based high-performance AE water reducing agent conforming to JIS A 6204 was used.
鉄筋は、表２に示す化学成分を有する２５φ×２００ｍｍの鉄筋を製造して用いた（鋼種Ｎｏ．１〜１５）。 Reinforcing bars were manufactured by using reinforcing bars of 25φ × 200 mm having chemical components shown in Table 2 (steel types No. 1 to 15).
表３に示す配合（配合Ｎｏ．１〜１２）により水和硬化体の材料をミキサで練混ぜ、φ１００×２００ｍｍの型枠に流し込み、養生してＮｏ．１〜１５の圧縮強度測定用のテストピースを製作した。圧縮強度の測定は、ＪＩＳ Ａ １１０８「コンクリートの圧縮強度試験方法」にしたがって行った。養生条件は標準養生２８日とした。また、同時に表３に示す鋼種の鉄筋を中心部に挿入したφ１００×２００ｍｍの中性化促進試験用のテストピースをＮｏ．１〜１５の各製造条件に付き２体製作した。養生条件は標準養生２８日とした。中性化促進試験は、標準養生２８日後のテストピースをＣＯ2濃度５％、温度４０℃、湿度６０％ＲＨの条件で９１日間暴露後、１体を５０ｍｍピッチで輪切りしたものについて、中性化深さを測定し、その平均値より評価した。中性化深さの測定は、フェノールフタレイン１％溶液噴霧法によって、無変色部を中性化部とした。 According to the composition shown in Table 3 (Formulation Nos. 1 to 12), the hydrated cured material was kneaded with a mixer, poured into a mold of φ100 × 200 mm, cured, and no. Test pieces for measuring the compressive strength of 1 to 15 were produced. The compressive strength was measured in accordance with JIS A 1108 “Concrete compressive strength test method”. The curing conditions were standard curing 28 days. At the same time, a test piece for a neutralization promotion test of φ100 × 200 mm in which a steel type reinforcing bar shown in Table 3 was inserted in the center was No. Two pieces were produced for each production condition of 1-15. The curing conditions were standard curing 28 days. The neutralization promotion test is a test piece that was exposed to a test piece after 28 days of standard curing for 91 days under conditions of CO 2 concentration 5%, temperature 40 ° C, and humidity 60% RH. The chemical depth was measured and evaluated from the average value. The neutralization depth was measured by using a phenolphthalein 1% solution spray method and setting the non-colored portion to the neutralized portion.
中性化促進試験を終えた試験体のうち輪切りにしなかったものを、耐塩害性試験に供した。耐塩害性試験は、６０℃の３％ＮａＣｌ水溶液に３日間浸漬した後に６０℃、５０％ＲＨの恒温恒湿槽で４日間乾燥することを１サイクルとし、これを１００サイクル繰り返した後に水和硬化体を破壊して鉄筋を取り出し、鉄筋を１０ｍａｓｓ％の水素クエン酸アンモニウム水溶液で除錆し、腐食面積率と最大腐食深さをマイクロメーターで測定した。 Of the specimens that had been subjected to the neutralization promotion test, those that were not cut into pieces were subjected to a salt damage resistance test. In the salt damage resistance test, one cycle consists of immersing in a 3% NaCl aqueous solution at 60 ° C. for 3 days and then drying in a constant temperature and humidity bath at 60 ° C. and 50% RH for one cycle. The hardened body was destroyed and the rebar was taken out. The rebar was derusted with a 10 mass% aqueous solution of ammonium hydrogen citrate, and the corrosion area ratio and the maximum corrosion depth were measured with a micrometer.
また、比較のために製鋼スラグ、高炉スラグ微粉末を用いない、普通コンクリートのテストピース（Ｎｏ．１６）を作製した。表４の配合によりコンクリートの材料をミキサで練り混ぜ、φ１００×２００ｍｍの型枠に流し込み、養生して、圧縮強度測定用および中性化促進試験用のテストピースを製作した。圧縮強度測定用のテストピースの養生条件は標準養生２８日とした。圧縮強度試験、中性化促進試験および耐塩害性試験は上記と同じように行なった。なお、骨材はＪＩＳ Ａ １１４５「骨材のアルカリシリカ反応性試験方法（化学法）」による試験において、「無害」と判定された良質なものを用いた。 For comparison, a test piece (No. 16) made of ordinary concrete without using steelmaking slag and blast furnace slag fine powder was prepared. Concrete materials having the composition shown in Table 4 were mixed with a mixer, poured into a mold of φ100 × 200 mm, and cured to produce test pieces for compressive strength measurement and neutralization promotion test. The curing conditions for the test pieces for compressive strength measurement were standard curing 28 days. The compressive strength test, neutralization acceleration test, and salt damage resistance test were performed in the same manner as described above. The aggregate used was a high-quality one determined to be “harmless” in the test according to JIS A 1145 “Aggregate Alkali Silica Reactivity Test Method (Chemical Method)”.
圧縮強度測定結果、中性化促進試験結果および耐塩害性試験結果を表３、４に併せて示す。製鋼スラグと高炉スラグ微粉末とを含有し、「ポルトランドセメント（ｋｇ／ｍ3）＋高炉セメント（ｋｇ／ｍ3）×０．６＋フライアッシュセメント（ｋｇ／ｍ3）×０．８５＋消石灰（ｋｇ／ｍ3）」（表３におけるＮＰ＋０.６ＢＢ＋０.８５ＦＢ＋ＣＨに相当）を５５ｋｇ／ｍ3以上含有し、所定の成分を有する鉄筋と組み合わせた水和硬化体（テストピースＮｏ．１〜９）は、良質な骨材を用いた水結合材比（水セメント比）５０％のテストピースＮｏ．１６（配合Ｎｏ．１３）の普通コンクリートよりも中性化深さが小さく、耐塩害性試験後も内部の鉄筋に腐食は認められなかった。一方、これらに該当しない水和硬化体と鉄筋を組み合わせた場合（テストピースＮｏ．１０〜１５）には、良質な骨材を用いた水結合材比５０％の普通コンクリート（テストピースＮｏ．１６）よりも耐中性化性に劣り、耐塩害性試験後に鉄筋の腐食が認められた。 The compression strength measurement results, neutralization promotion test results, and salt damage resistance test results are also shown in Tables 3 and 4. Steelmaking slag and blast furnace slag fine powder, "Portland cement (kg / m 3 ) + blast furnace cement (kg / m 3 ) x 0.6 + fly ash cement (kg / m 3 ) x 0.85 + slaked lime (kg / M 3 ) ”(corresponding to NP + 0.6BB + 0.85FB + CH in Table 3) 55 kg / m 3 or more, and a hydrated cured body (test pieces No. 1 to 9) combined with a reinforcing bar having a predetermined component, Test piece No. 50% water binding material ratio (water cement ratio) using good quality aggregates. The neutralization depth was smaller than that of ordinary concrete of No. 16 (Compound No. 13), and no corrosion was observed in the internal reinforcing bars even after the salt damage resistance test. On the other hand, when a hydrated hardened body and a reinforcing bar not corresponding to these are combined (test pieces No. 10 to 15), ordinary concrete (test piece No. 16) having a water bonding material ratio of 50% using a high-quality aggregate is used. ) Was inferior in resistance to neutralization, and corrosion of the reinforcing bars was observed after the salt damage resistance test.
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| JP3582263B2 (en) * | 1996-11-21 | 2004-10-27 | Ｊｆｅスチール株式会社 | Hydrated product using steelmaking slag |
| AU749066B2 (en) * | 1998-06-17 | 2002-06-20 | Kawasaki Steel Corporation | Weatherable steel material |
| JP4736157B2 (en) * | 2000-03-24 | 2011-07-27 | Ｊｆｅスチール株式会社 | Solidification method of steelmaking slag |
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