水淬高爐石取代海砂細骨材可行性研究

Abstract

為探討以水淬高爐石取代海砂細骨材使用的可行性，本研究以中鋼生 產的水淬高爐石為研究對象，探討對不同取代量下的水淬高爐石混凝土之 工程性質。研究中有三種不同細度模數的海砂，採五種不同取代量，配比 設計採一種坍度、四種水灰比的條件下，比較不同取代量下的水淬高爐石 混凝土之工程性質，其中包括工作度、抗壓強度、抗拉強度、耐久性、透 水性、凝結、乾縮等。 水淬高爐石顆粒大部分成圓球狀，流動性佳， 可提高工作度；且隨取代量的增加可減低用水量，但因比重大，取代量越 多泌水越嚴重，骨材析離亦越顯著。故取代量以40%-55%為最佳，隨著海 砂細骨材細度模數的提高，可適度的減少取代量。 研究結果顯示，各 不同取代量下的水淬高爐石混凝土抗壓強度均大於全為海砂混凝土抗壓強 度；抗拉強度和水密性之變化則類似抗壓強度之變化；隨取代量的增加， 耐久性越高，乾縮量越少，凝結時間越往後延遲。 To conform usability of water-quenched BF slag substitution offshore sand,the effect on concrete by water-quenched BF slag, which produced by China Steel Corp.,in different percentage of substitute was inve-stigate. Under the conditions of 3 different fineness modulous of offshore sand,5 different slag substitutes,1 slump and 4 different water-cement ratios, properties such as workability,compressive strength,tensile strength,durability,diffusibility,elapsing time,agg-regation, etc., of concrete composed of different substitutes of water- quenched BF slag were compared.The particles of water-quenched BF slag are mostly in globular shape and with good flowability. The workability then can be enhanced and the consumption of water can be reduced as the ratio of substitution increased. However,the bleeding and segregation also become more prominent when the ratio of substitution increased due to its high specific gravity. Therefore,the best ratio of substitution is around 40% to 55%. The substitution may be reasonably reduced if the fineness modulous of offshore sand can be enhanced.The results of this study showed that the compressive strength of all concrete composed of water-quenched BF slag in different substitution were better than that of concrete composed of offshore sand. The change of tensile strength and water tightness are similar to that of compressive strength.As the substitution increased,the durability was enhanc-ed,the shrinkage lessened,and the time of aggregation delayed.