電弧爐氧化碴係電弧爐煉鋼過程所產生的副產物，由於產生量甚為龐大且以往未妥善再利用而任意棄置，因此普遍認定其為廢棄物。在河川砂石欠缺及環保意識逐漸抬頭的今日，將爐碴透過適當的加工處理程序，予以資源化再利用，為工程界極為重要的課題，本研究即針對氧化碴替代天然骨材拌製成混凝土之各項特性進行完整探討。 經破碎、磁選與篩分後之氧化碴在實驗室中進行之試驗包括氧化碴材料之基本化學成分與物理性質分析、礦物組成、膨脹試驗、環境影響試驗、鹼質粒料反應試驗、混凝土配合設計與強度試驗與微觀分析等。 台灣地區23廠電弧爐爐碴材料之化性、物性分析結果顯示，各廠爐碴之化學成分略有差異，物理性質方面，顆粒強度及耐磨損性甚佳，面乾飽和比重較一般碎石比重為高，吸水率及乾搗單位重與天然骨材相當，健度損失甚低，不產生鹼質反應，洛杉磯磨損率平均約25﹪，符合CNS混凝土用骨材之規定。此外，浸水膨脹試驗顯示爐碴會產生少量之膨脹(約0.1%)，故需經安定化處理後方可應用於混凝土中。 針對23廠電弧爐爐碴經毒性特性溶出試驗(TCLP)結果顯示，重金屬溶出量均遠低於環保署有害廢棄物溶出試驗認定標準，且pH值介於9.3~12.1之間，可認定為無害之一般廢棄物。爐碴泡水後之水質分析符合國內農業灌溉用水標準及國家放流水標準，且爐碴材料不具輻射性，因此電弧爐爐碴充當工程材料不會對環境造成二次污染。 爐碴取代天然粗骨材拌製之爐碴混凝土，由於爐碴顆粒表面粗糙及多稜角特性有助於漿料與骨材間之鍵結，加上卜作嵐反應作用及被解離出之活性鈣、矽離子於水泥水化過程中繼續作用生成水化矽酸鈣，因而提昇骨材與水泥砂漿界面之鍵結力，使得爐碴混凝土強度發展優於天然骨材混凝土。 除實驗室內之評估外，同時亦經試驗道路鋪築之實用化驗證與評估，證實電弧爐氧化碴確可替代天然骨材而應用於混凝土工程中。 Electrical arc furnace oxidizing slag is the by-product produced by the steelmaking plants from using recycled iron. The growing demand for steel has resulted in significant increase in the production of electrical arc furnace slag. Also, disposal of the slag has become more costly to the steelmaking industry due to stringent environmental regulations. Therefore, interest in this slag as a substitute for conventional construction material has increased considerably in recent years. The utilization of the slag not only solves a waste disposal problem but also provides an economic construction material. This study assesses those properties of electrical arc furnace slag that are likely to affect its use as a replacement for conventional aggregate in making concrete. After crushing and screening processes, electric arc furnace oxidizing slag was evaluated, in the laboratory, for the potential as an alternative of aggregate in making concrete. Tests included complete chemical analysis and physical properties, Mineral composition, expansion test, environmental influence test, Toxicity characteristic leaching procedure, alkali aggregate reaction, concrete mix design and strength development, Microstructure analysis and test pavement build. ………. The economic potential of the utilization of slag as construction materials demand more versatile applications of this by-product. This study demonstrated that the incorporation of slag in concrete is feasible. More areas in construction related applications of electric arc furnace slag are yet to be developed.
