건설오니(슬라임)를 이용한 친환경 기초공법 개발에 관한 연구

다국어 초록 (Multilingual Abstract)

During the construction of ground improvement methods such as high-pressure jet grouting and deep mixing in soft ground, cementitious construction sludge (slime) is generated. Although this sludge develops high strength during curing due to its cement-based slurry properties, it is currently disposed of as construction waste, together with other types of sludge (e.g., sewage sludge, wheel-washing sludge, and bentonite mixtures). This practice not only raises environmental concerns, but also leads to increasing social costs.
To solve this problem, the objective of this study was to develop an eco-friendly foundation method that utilizes cementitious construction sludge as part of a structural body, rather than treating it solely as waste. To this end, the physical and mechanical properties of sludge specimens were analyzed. Variations in unconfined compressive strength were examined through mix design and strength testing according to the proportions of recycled aggregate and binders. Increasing the recycled aggregate content by 10% resulted in a strength improvement of approximately 155%, whereas a 20% increase resulted in an improvement of approximately 175%.
It is concluded that construction sludge generated from ground improvement methods is a viable environmentally friendly and economical alternative for ground structures when properly mixed with recycled aggregates and binders.
To compare conventional and eco-friendly foundation methods, a hypothetical design scenario was established in which a uniformly distributed load of 100 kN/m² acts on a foundation measuring 20 m × 20 m with a depth of 2.0 m. Actual foundation designs were conducted under these conditions. For the conventional method, shallow foundations were found to be unsuitable due to excessive elastic settlement (max. 204.9 mm), whereas pile foundations using a 10×10 grid of D508-9T steel pipe piles (spacing 4.0D, socketed into rock by≥ 1D) satisfied the required stability criteria. In the eco-friendly method, numerical parametric studies were performed to determine the optimal ground improvement layout and configuration that meet allowable settlement criteria. The analysis indicated that a 2.0 m-thick layer of slime-treated soil, combined with a 10×10 array of D1000 JSP columns spaced at 2D and centrally concentrated, produced the minimum and most uniform settlement, thus representing the optimal foundation scheme for the given conditions.
Within these constraints, quantity calculations and preliminary construction costs (BOQ) were estimated for the hypothetical scenario. Compared to the conventional (steel pipe pile) method, the eco-friendly foundation reinforcement method utilizing construction sludge (slime) showed up to approximately 40% in potential cost savings. Complete resource utilization of the generated construction sludge is projected to save around 220 million KRW in construction waste disposal fees, reduce CO emissions by 3,679 tonf via decreased truck transportation and₂ landfill use, enable additional landfill capacity, and provide further energy savings demonstrating both quantitative and qualitative social value.
Although based on limited scenarios, these results show that construction sludge generated by high-pressure jetting can meet required strength and quality standards for ground structures when recycled with native soil, recycled aggregate, and binders at appropriate mix ratios. For broader application, further standardized testing and field validation under diverse construction conditions are required, including the establishment of quality control criteria for different types of construction sludge. Recognition of construction sludge as a reusable resource, rather than as waste, and supporting legal, administrative, and financial frameworks will be essential to advance sustainable reuse in the construction industry.

목차 (Table of Contents)

• 제 1장 서 론 1
• 1.1 연구배경 및 목적 1
• 1.2 연구내용 및 구성 5
• 제2장 이론적 배경 및 연구동향 7
• 2.1 건설폐기물 발생현황 7
• 2.1.1 국내 폐기물 및 건설폐기물 현황 7
• 2.1.2 건설폐기물의 처리 11
• 2.2 국내 관련법 현황 12
• 2.3 고화의 원리 15
• 2.3.1 고화의 정의 15
• 2.3.2 고화의 원리 15
• 2.4 건설오니 자원활용에 대한 연구동향 19
• 2.4.1 국내 연구동향 19
• 2.4.2 해외 연구동향 21
• 제3장 건설오니 슬라임 를 이용한 친환경 기초공법 개념 23
• 3.1 공법 개요 23
• 3.2 제안된 공법에 대한 Concept Design 24
• 3.2.1 [Step 1] 기초시공을 위한 지반굴착 단계 24
• 3.2.2 [Step 2] 연약지반 개량 및 건설오니 생성 단계 25
• 3.2.3 [Step 3] 친환경 슬래브 구간 연속화 단계 26
• 3.2.4 [Step 4] 건설오니 개량체를 이용한 친환경 슬래브 타설 27
• 3.2.5 [Step 5] 버림 콘크리트 타설 및 본 구조물 시공 27
• 제4장 건설오니(슬라임) 개량체의 물리 및 역학 특성 분석 29
• 4.1 실내 배합시험에 따른 역학적 특성 분석 29
• 4.1.1 실내배합시험 개요 29
• 4.1.2 시험시료에 대한 물성 특성 31
• 4.1.3 모르타르 배합시험 및 강도시험 결과 34
• 4.2 건설오니 화학적 특성 분석 39
• 4.2.1 개량 전 후 미세구조 및 응집 특성 분석(SEM) 39
• 4.2.2 개량된 건설오니 화학성분 분석(EDS) 41
• 제5장 가상사례를 통한 친환경 기초공법 적용성 검토 43
• 5.1 가상사례 설계조건 43
• 5.1.1 지반특성 및 기초구조물 조건 43
• 5.1.2 적용 설계기준 및 설계지반정수 44
• 5.2 직접기초 적용성 검토 45
• 5.2.1 설계조건 45
• 5.2.2 직접기초 안정성 검토결과 46
• 5.3 일반공법(말뚝기초) 적용성 검토 47
• 5.3.1 설계조건 47
• 5.3.2 기초구조물 검토결과 48
• 5.3.3 말뚝기초 안정성 검토결과 50
• 5.4 친환경기초 적용성 검토 54
• 5.4.1 설계조건 54
• 5.4.2 친환경기초 안정성 검토결과 55
• 5.5 개략공사비 산정을 통한 경제적 사회적 예상가치 검토 58
• 5.5.1 공법별 주요 수량 비교 59
• 5.5.2 친환경공법 경제적 예상가치 검토 60
• 5.5.3 친환경공법 사회적 예상가치 검토 62
• 제6장 결론 및 추후 연구과제 64
• 6.1 결론 64
• 6.2 추후 연구과제 67
• 참고문헌 69
• 부 록 73