천연골재의 부족으로 골재 수급이 날이 갈수록 심각해지면서 재활용 가능한 재료에 대한 사회적 관심이 높아지고 있다. 하지만 국내에서는 선진외국에 비해 순환골재에 대한 연구데이터와 그를 사용한 현장 적용실정이 매우 부족한 실정이다. 본 논문에서는 현장에서 사용하는 레미콘 사의 가이드 배합에 순환골재를 전량 치환하는 배합비를 추출하여 압축강도를 평가하였 고 추출된 배합비의 순환골재 콘크리트를 원형강관 내부에 충전하여 순환골재콘크리트충전 합성기둥이 국내ㆍ국외 설계식을 반 영한 내력과 비교하여 구조부재로써 사용이 적합하다고 사료되는 결과를 얻었다. 또한, 강관의 콘크리트 구속효과로 인해 강관 내부의 콘크리트 강도가 미세하게 증가함을 확인하였다.

Recycled aggregate is a solution to reduce construction waste and to be environmentally friendly, but concrete using it has various disadvantages in terms of structure. Therefore, the interaction effect of the two materials can be expected by filling the cyclic aggregate concrete in the CFT column. Eighteen specimens were constructed to confirm the compressive behavior of RCFT (Recylced Concrete Filled Tube) columns, which can be applied to real buildings by making high strength concrete with recycled aggregate. Variable is the shape and thickness of steel pipe, concrete strength and mixing ratio, and coarse aggregate and fine aggregate are all used as recycled aggregate. A total of three recycled aggregate concrete preformulations were used to find the optimal mixing ratio and the compressive behavior was analyzed through the load - displacement curves of RCFT columns.

Concrete using recycled aggregate instead of natural aggregate reduces environmental waste and is a future oriented material. However, use of the structure is limited to negative recognition of recycled aggregate quality. In this study, 50 MPa concrete was developed using recycled aggregate. In order to verify the possibility of using as a column member, we aimed to confirm the compressive behavior of RCFT (Recycled Concrete Filled Tube) columns filled with concrete using recycled aggregate. Circular type steel pipe was used, and concrete strength (30, 40, 50MPa) and mixing ratio were the experimental parameters. Through 72 specimen compression tests, 50MPa strength of recycled aggregate concrete was confirmed and stable behavior of 9 RCFT columns was confirmed.