• Advances in concrete construction
• /
• 제6권3호
• /
• pp.221-243
• /
• 2018

Utilization of mine waste rocks and tailings in concrete as aggregates will help in sustainable and greener development. The literature shows the potential use of iron ore tailings as a replacement of natural fine aggregates. As natural sand reserves are depleting day by day, there is a need for substitution for sand in concrete. A comprehensive overview of the published literature on the use of iron ore waste and tailings and other industrial waste in concrete is being presented. The effect of various properties such as workability, compressive strength, split tensile strength, flexural strength, durability and microstructure of concrete have been presented in this paper.

• 자원리싸이클링
• /
• 제25권4호
• /
• pp.23-31
• /
• 2016

양양철광산 선광 부산물(폐석, 광미)의 폐기물공정시험기준에 의한 중금속용출량은 환경기준값 보다 낮아 유해성이 없으므로 그 자체를 물질전환법에 의해 순환자원화 하는 데는 문제가 없다. 선광 광미를 시멘트 부원료로 사용할 경우에는 시멘트 품질안정성 차원에서 전 알카리($R_2O$)함량이 포틀랜드 시멘트(KS L 5201) 품질 기준치인 0.6%를 초과하지 않도록 광미 첨가량을 3%이하로 사용하는 것이 좋다고 판단된다. 재활용 점토벽돌(KS I 3013) 1종 규격에 부합되는 비소성 에코벽돌은 무기결합제의 15%를 광미로 그리고 일반잔골재의 100%를 철광산 폐석으로 대체하여 제조 가능하였다. 이처럼 선광 부산물을 시멘트 부원료 및 비소성 에코벽돌로 순환자원화함으로서 광미 적치장의 축소 및 유지관리비용 절감 그리고 에너지 사용 및 $CO_2$ 발생 절감으로 환경적 효과 및 경제적 효과를 동시에 얻을 수 있을 것이다.

• Advances in concrete construction
• /
• 제5권3호
• /
• pp.201-219
• /
• 2017

With the rapid growth in construction sector, it becomes all the more important to assess the amount of Construction and Demolition (C&D) waste being generated and analyze the practices needed to handle and use this waste before final disposal. This serves waste management and disposal issues, paving way to waste utilization in construction industry from the sustainability point of view. C&D waste constitutes a major bulk of total solid waste produced in the world. In this work, an attempt is made to study the performance of concrete using water soaked Recycled Coarse Aggregates (RCA) in replacement levels of 0%, 25%, 50%, 75% and 100% to Natural Coarse Aggregates (NCA). Experiments were designed and conducted to study the performance of RCA based concrete. Further suitable performance enhancement techniques to RCA based concrete were attempted, to achieve compressive strength at least equal to or more than that for no RCA based concrete (control concrete). Performance enhancement study is reported here for 50% and 100% RCA based concretes. All four techniques attempted have given favorable results encouraging use of RCA based concretes with full replacement levels, to adopt RCA based concrete in structural applications, without any kind of concern to the stake holder. Further attempts have also been made to use Recycled Fine Aggregates (RFA) with appropriate modifications to serve as fine aggregates in mortar and concrete. Using RFA blended with river sand fractions as well as RFA with Iron Ore Tailings (IOT) fractions, have given good results to serve as fine aggregates to the extent of 100% replacement levels in mortars and concretes.

• Advances in concrete construction
• /
• 제3권1호
• /
• pp.55-69
• /
• 2015

Tailing Material (TM) and Fly Ash (FA) are obtained as waste products from the mining and thermal industries. Studies were carried out to explore the possibility of utilizing TM as a part replacement to fine aggregate and FA as a part replacement to cement, in concrete mixes. The effect of replacing fine aggregate by TM and cement by FA on the standard sized specimen for compressive strength, split tensile strength, and flexural strengths are evaluated in this study. The concrete mix of M40 grade was adopted with water cement ratio equal to 0.40. Concrete mix with 35% TM and 65% natural sand (TM35/S65) has shown superior performance in strength as against (TM0/S100, TM30/S70, TM40/S60, TM50/S50, and TM60/S40). For this composition, studies were performed to propose the optimal replacement of Ordinary Portland Cement (OPC) by FA (Replacement levels studied were 20%, 30%, 40% and 50%). Replacement level of 20% OPC by FA, has shown about 0-5% more compressive strength as against the control mix, for both 28 day and 56 days of water curing. Interestingly results of split tensile and flexural strengths for 20% OPC replaced by FA, have shown strengths equal to that of no replacement (control mix).