산업부산물을 활용한 저강도 고유동 채움재의 유동성 및 물성평가

Properties Evaluation and flowability of Controlled Low Strength Materials Utilizing Industrial By-Products

Abstract

산업부산물인 화력발전소 석탄재와 제강슬래그의 활용방안을 확대하고, 폐광산의 지반침하를 방지하기 위해 저강도 고유동 채움재를 제조하였다. 중금속 용출 억제 등의 환경적 안정성을 확보하기 위해 화력발전소 바닥재(bottom ash)와 KR슬래그는 7:3으로 혼합하여 탄산화반응($CO_2$고정화)을 실시하였다. 효율적인 폐광산 충진을 위해 유동성에 따른 작업성 평가와 물성평가를 실시하였다. 유해성 분석결과 탄산화 반응을 실시할 경우 중금속 용출이 억제되는 것을 확인하였다. 비표면적 차이에 의해 각 배합별 물 비율을 확인하였다. flow 차이에 따른 작업 효율성을 평가한 결과 flow 300mm의 경우 flow 260mm 대비 효과적으로 충진이 가능한 것을 확인하였다. 압축강도 측정결과 flow 300mm 대비 flow 260mm의 경우 단위수량 감소로 인한 공극수가 적어 압축강도가 상대적으로 높은 것을 확인하였다.

The purpose of this study is to expand the use of coal ash and coal slag in thermal power plants. In addition, controlled low strength materials was developed to prevent mine settlement. Bottom ash and KR slag are mixed at ratio of 7:3 to expand the use of industrial by-products through carbonate reaction and inhibit the exudation of heavy metals. In order to efficiently fill the abandon mine, workability and physical properties were evaluated according to flow. As a result of elution of harmful substance experiment, it was confirmed that the carbonation reaction inhibited the elution of heavy metals. It was confirmed that the difference in water ratio was the difference in specific surface area of the controlled low strength materials. It was confirmed that the working efficiency is excellent when the flowability is 300mm compared to 260mm. compressive strength measurement result was relatively high at 260mm compared to 300mm because the number of pores due to decrease of water ratio was small.

Fig 1. Water ratio of controlled low strength materials of flow:260mm(A) and flow:300mm(B)

Fig 2. Compressive strength of controlled low strength materials of flow:260mm(A) and flow:300mm(B)

Table 1. Compositions of controlled low strength materials

Table 2. Chemical composition of bottom ash, slag and pc Bottom ash : kr slag

Table 3. Elution of harmful substance of pc bottom ash : kr slag

Table 4. V-Funnel and l-flow test of controlled low strength materials