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Properties of non-cement mortars with small addition of alkali activator using fly ash and fused waste slag

석탄회 및 용융폐기물 슬래그에 소량의 알칼리 활성화제를 첨가한 무시멘트 모르타르의 특성

  • Kim, Yootaek (Department of Advanced Materials Science and Engineering, Kyonggi University) ;
  • Lee, Kyongwoo (Department of Advanced Materials Science and Engineering, Kyonggi University)
  • 김유택 (경기대학교 신소재공학과) ;
  • 이경우 (경기대학교 신소재공학과)
  • Received : 2015.09.02
  • Accepted : 2015.09.25
  • Published : 2015.12.31

Abstract

Recently the world wide efforts reduce occurrence of $CO_2$; global warming main reason. The aim of this study is to improve recycling rate of the fly ash (FA) and fused waste slag (FWS) from the power plant and to carbonate under supercritical condition ($40^{\circ}C$, $80kgf/cm^2$ pressure, 60 min) for $CO_2$ fixation. Specimens of mortar with various mixing ratios of FA, FWS (from 100:0 to 20:80 in 5 steps of 20 % reduction each time), distilled water and 3 M NaOH alkali activators were prepared. As a result, the proportion of weight change ratio increases with CaO content, to 12 % after carbonation under the supercritical condition. There is difference of compressive strength between the carbonated and the alkali activator mortar specimens. The stabilization of $CO_2$ fixation through carbonation which could confirm the applicability of the eco-friendly materials without loss of compressive strength.

현재 전 세계적으로 지구온난화의 주범인 $CO_2$ 저감을 위한 노력을 하고 있으며, 산업발전에 필요한 화력발전 등에서 발생한 부산물을 재활용하는 방안이 시급하다. 따라서 본 연구는 산업부산물인 비산재와 폐기물 슬래그를 이용하여 모르타르 경화체를 제작하였으며 알칼리 활성화제 첨가에 따른 물성을 비교하기 위해 비교적 낮은 농도인 3 M의 NaOH solution을 사용하였고, 이 경화체에 초임계 이산화탄소 조건($40^{\circ}C$, $80kgf/cm^2$ pressure, 60 min)에서 탄산화를 통하여 $CO_2$를 경화 체내에 안정적으로 고정화 시켜 이에 따른 물성을 평가하였다. 탄산화 인자인 CaO의 함량이 많을수록 탄산화율은 높게 나타났으며, 탄산화 후 무게변화율이 최대 약 12 % 증가하였다. 탄산화 후 압축강도는 전과 비슷한 수준이었으며, 이를 통해 탄산화를 통해 $CO_2$를 안정하게 고정화시킨 친환경 소재에 적용 가능성을 확인할 수 있었다. 또한 탄산화 반응 후에 생성되는 $H_2O$로 인해 추가적인 양생을 통해 장기적인 관점에서 탄산화를 통해 물성향상 또한 기대해 볼 수 있을 것으로 생각된다.

Keywords

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