報告書番号

380008

タイトル（和文）

電炉製鉄筋の性能の実態に関する試験

タイトル（英文）

EVALUATION OF THE EXISTING PROPERTIES AND PERFORMANCE OF ELECTRIC FURNACE REINFORCING BARS

概要 （図表や脚注は「報告書全文」に掲載しております）

従来，電力会社では建設工事に使用する鋼材は高炉メーカーの製品が指定されており，鉄筋についても電炉メーカーの製品は，指定外となっている。これは，電炉鉄筋はスクラップを原料としていることから材質のばらつき，供給不安定等世評が芳しくないことが背景にあるこめと考えられる。しかし，一方では価格が安いためコストダウンの水深に将用を促す様子もある。本研究は，電炉鉄筋の品質及び性能を明らかにするために関東以北の標準サイズ（Ｄ１９，Ｄ２２，Ｄ２５）以上の敵機を製造している電炉メーカー９社１０工場及び比較用として高炉メーカー１社の異形鉄筋（ＳＤ３５）７８０本について確性試験を行い，統計整理したものである。

概要 （英文）

THE ANNUAL PRODUCTION OF DEFORMED BARS IN JAPAN AMOUNTS TO ABOUT 12,000,000 TONS.BUT THE SHARE OF LARGE BLAST FURNACE IRON AND STEEL MAKERS ACCOUNTS FOR ONLY ABOUT 5%,AND THE REST(I.E.95%)IS SUPPLIED BY SMALLER ELECTRIC FURNACE IRON AND STEEL MAKERS. UNTIL NOW,SINCE ELECTRIC POWER COMPANIES THEMSELVES HAVE USUALLY SPECIFIED BLAST FURNACE STEEL MATERIALS TO BE USED IN THEIR CONSTRUCTION WORKS,ELECTRIC(FURNACE)REINFORCING BARS HAVE ALSO BEEN REJECTED.THE FOLLOWING FACTS SEEM TO FORM THE BACKGROUND OF THESE TRENDS;INSTABILITY OF THEIR SUPPLY DUE TO THEIR HIGH SENSITIVITY TO MARKET CONDITIONS;POSSIBLE FLUCTUATIONS IN STRENGTHS AND CHEMICAL COMPOSITION WHICH ARE INHERENT IN THE USE OF SCRAP IRON AS THEIR RAW MATERIAL;AND LASTLY,NOT VERY FAVOURABLE REPUTATION. RECENTLY,THE TOHOKU ELECTRIC POWER CO.HAS REVEALED AND INTENTION TO USE THESE ELECTRIC BARS,AND FELT IT NECESSARY TO HAVE CLEAR UNDERSTANDING OF THE QUALITY AND PERFORMANCE OF THESE BARS.THUS OUR INSTITUTE WAS REQUESTED TO UNDERTAKE CONFIRMATION TESTS AND EVALUATE THE RESULTS. IN THIS REPORT,THE RESULTS OF THE CONFIRMATION TESTS AND STATISTICAL ANALYSES FROM THE ABOVE-MENTIONED POINT OF VIEW ARE SHOWN.SPECIMENS WERE COLLECTED FROM TEN WORKS OF NINE ELECTRIC IRON AND STEEL MAKERS PRODUCING THE BARS OF STANDARD(D19,D22,AND D26)AND LARGER SIZES.ALL THESEWORKS ARE LOCATED IN KANTO DISTRICT OR NORTH OF IT.FOR COMPARISON,SAMPLES FROM A BLAST FURNACE IRON AND STEEL MAKER WERE ALSO TESTED.THE CONFIRMATION TEST WITH 780 PIECES OF DEFORMED BARS(SD35)WAS CONDUCTED AND THE RESULTS WERE ANALYZED STATISTICALLY.

報告者

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