• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.25-30
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• 2003

Owing to the deterioration of reconstruction and the construction, much of the construction waste is discharged in our construction field. By supplementing aggregate resources that are insufficient by recycling waste concrete, it is considered that the resource-preserving effect according to the saving and reuse of resource as well as eco-friendly effect that is regarded as important in recent industrial society may be expected. In this study conducted an experiment by setting up 15 levels according to the variations in the rate of substitution of recycled coarse aggregate by the water cement ratio(40, 50, 60%). As the result of it, the slump and air contents was increased by ratio of coarse aggregate, and the elapsed characteristics by the ratio of recycled coarse aggregate showed that there is no clear difference in slump and the air contents. Further, in the characteristics of strength development, the lower the water cement ratio, the higher the compressive strength at early ages, compared with crushed stone, while the compression declined according to the increase of substitution rate of recycled gravel as it was tending upward long-term ages.

• 한국디지털건축인테리어학회논문집
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• 제12권3호
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• pp.59-66
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• 2012

Autoclaved Lightweight Concrete(ALC) features such as a high performance insulation, the fire resistance, the advantage of easy handing construction, and lightweight panels applied the curtain wall system. ALC materials are certified as non-toxic environmental and eco-friendly productions. But ALC external panels mixed with blast furnace slag pounder and silica fume have to be coated with a stucco compound or plaster because of resisting the ambient environment. This study is that mixing tests to evaluate a performance analysis of exterior paints to be make-up pigments(organic or inorganic) coated with panel surface. Testing compared by KS F 2476; flow test, KS F 2426; compression strength test, KS F 2762; bond strength test. In results, the case of the inorganic binder, ratio of alumina cement : anhydrite is 90:10 to 80:20 at the highest level of intensity. In the case of the organic binder, adhesive strength rating at surface of ALC, the pullout strength is below 0.5 $N/mm^2$ but the normal concrete is over 2.0$N/mm^2$. A contents ratio of EVA resin is more than 3% and then bond strength is effectively.

• Advances in concrete construction
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• 제13권 2호
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• pp.183-190
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• 2022

A wide range of experimental bases and improved performance with different forms of Fiber Reinforced Polymer (FRP) have attracted researchers to produce eco-friendly and sustainable structures. The reinforced concrete (RC) beam's shear capacity has remained a complex phenomenon because of various parameters affecting. Design recommendations for the shear capacity of RC elements having FRP reinforcement need a more experimental database to improve design recommendations because almost all the recommendations replace different parameters with FRP's. Steel and FRP are fundamentally different materials. One is ductile and isotropic, whereas the other is brittle and orthotropic. This paper presents experimental results of the investigation on the beams with glass fiber reinforced polymer (GFRP) reinforcement as longitudinal bars and stirrups. Total twelve beams with GFRP reinforcement were prepared and tested. The cross-section of the beams was rectangular of size 230 × 300 mm, and the total length was 2000 mm with a span of 1800 mm. The beams are designed for simply-supported conditions with the two-point load as per specified load positions for different beams. Flexural reinforcement provided is for the balanced conditions as the beams were supposed to test for shear. Two main variables, such as shear span and spacing of stirrups, were incorporated. The beams were designed as per American Concrete Institute (ACI) ACI 440.1R-15. Relation of VExp./VPred. is derived with axial stiffness, span to depth ratio, and stirrups spacing, from which it is observed that current design provisions provide overestimation, particularly at lower stirrups spacing.

• Computers and Concrete
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• 제30권6호
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• pp.421-432
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• 2022

Recently, the interminable ozone depletion and the global warming concerns has led to construction industries to seek for construction materials which are eco-friendly. Regarding this, Geopolymer Concrete (GPC) is getting great interest from researchers and scientists, since it can operate by-product waste to replace cement which can lead to the reduction of greenhouse gas emission through its production. Also, compared to ordinary concrete, geopolymer concrete belongs improved mechanical and durability properties. In spite of its positive properties, the practical use of geopolymer concrete is currently limited. This is primarily owing to the scarce structural, design and application knowledge. This study investigates the Mechanical and Durability of Geopolymer Concrete Containing Fibers and Recycled Aggregate. Mixtures of elastoplastic fiber reinforced geopolymer concrete with partial replacement of recycled coarse aggregate in different proportions of 10, 20, 30, and 40% with natural aggregate were fabricated. On the other hand, geopolymer concrete of 100% natural aggregate was prepared as a control specimen. To consider both strength and durability properties and to evaluate the combined effect of recycled coarse aggregate and elastoplastic fiber, an elastoplastic fiber with the ratio of 0.4% and 0.8% were incorporated. The highest compressive strength achieved was 35 MPa when the incorporation of recycled aggregates was 10% with the inclusion of 0.4% elastoplastic fiber. From the result, it was noticed that incorporation of 10% recycled aggregate with 0.8% of the elastoplastic fiber is the perfect combination that can give a GPC having enhanced tensile strength. When specimens exposed to freezing-thawing condition, the physical appearance, compressive strength, weight loss, and ultrasonic pulse velocity of the samples was investigated. In general, all specimens tested performed resistance to freezing thawing. the obtained results indicated that combination of recycled aggregate and elastoplastic fiber up to some extent could be achieved a geopolymer concrete that can replace conventional concrete.

• 콘크리트학회논문집
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• 제22권5호
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• pp.685-694
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• 2010

지금까지 환경 친화적 재료로서 황토에 관한 연구는 포틀랜드 시멘트를 부분적 대체하거나, 완전 대체하는 연구로 진행되어 왔다. 기존의 대부분의 연구에서는 압축강도, 건조수축, 크리프 등 황토 콘크리트의 역학적 성질에 초점이 맞춰졌다. 이 연구에서는 황토 콘크리트로 제작된 보 실험체의 전단강도를 실험하였다. 또한 황토 콘크리트에 정착된 인장 철근의 부착강도를 실험하였다. 이번 실험에서 시멘트를 20% 대체하는 활성 황토와 시멘트를 100% 대체하는 활성 황토를 사용한 콘크리트가 사용되었다. 실험 결과, 시멘트 20% 대체 활성 황토와 무시멘트 활성 황토 콘크리트 보의 전단 강도는 일반 포틀랜드 시멘트 콘크리트 보와 동등하였다. 반면에, 무시멘트 활성 황토 콘크리트의 부착 강도는 일반 포틀랜드 시멘트 콘크리트보다 작았다.

• 한국문헌정보학회지
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• 제54권2호
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• pp.5-28
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• 2020

도서관에 디지털 자원 및 IT자원을 적극적으로 적용하고 활용함으로써 지구의 지속가능성에 기여할 수 있는 구체적인 방법에 대해서 논의하기 위해 본 연구가 수행되었다. 이를 위해 공공도서관 사서들을 대상으로 설문조사를 하였으며, 그 결과는 다음과 같다. 첫째, 사서들의 환경문제의 심각성에 대한 인식 및 친환경활동 실천정도는 매우 높게 나타났으나, 도서관 그린 IT에 대한 인식이나 친환경관련 용어에 대한 친숙도는 매우 낮게 나타났다. 그럼에도 불구하고 도서관에 그린 IT를 적용하는 것의 중요성에 대해서는 높은 동의도를 보여주었다. 둘째, 친환경성 및 도서관의 녹색화에 가장 높은 기여도가 있다고 평가된 영역은 장비 및 제품 운영 영역으로 나타났으며, 다음으로 서비스 영역, 네트워크 및 시스템 영역 순으로 나타났다. 셋째, 도서관 그린 IT화가 사회적으로 어떤 영향력이 있을 것이라 생각하는지에 대해 사회적 기반시설로서 도서관의 사회적 책임에 대한 인식을 증진할 수 있다는 의견이 가장 높게 나타났다. 결론적으로 도서관의 그린 IT화는 도서관이 사회적 기반시설로서 사회적 책임을 지고 있는 기관으로 국민들이 인식되게 함으로써 도서관에 대한 인식을 개선하는데 기여할 수 있을 것으로 보인다.

• Advances in concrete construction
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• 제10권2호
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• pp.93-104
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• 2020

Basalt fiber is an eco-friendly fiber and comparatively newer to the world of fiber-reinforced polymer (FRP) composites. A limited number of studies have been reported in the literature on the strengthening of reinforced concrete (RC) beams with basalt fiber reinforced polymer (BFRP). The present experimental work explores the feasibility of using the BFRP strips for shear strengthening of the RC beams. The strengthening schemes include full wrap and U-wrap. A simple mechanical anchorage scheme has been introduced to prevent the debonding of U-wrap as well as to utilize the full capacity of the BFRP composite. The effect of varying shear span-to-effective depth (a/d) ratio on the behavior of shear deficient RC beams strengthened with BFRP strips under different schemes is examined. The RC beams were tested under a four-point loading system. The study finds that the beams strengthened with and without BFRP strips fails in shear for a/d ratio 2.5 and the enhancement of the shear capacity of strengthened beams ranges from 5% to 20%. However, the strengthened beams fail in flexure, and the control beam fails in shear for a higher a/d ratio, i.e., 3.5. The experimental results of the present study have been compared with the analytical study and found that the latter gives conservative results.

• Advances in concrete construction
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• 제14권5호
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• pp.355-368
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• 2022

This paper investigates the impact of length and volume fractions (VFs) of banana fibres (BFs) on the mechanical and physical properties of concrete. The mechanical properties were compressive strength, splitting tensile, flexural strength, and bond stress, while the physical properties were unit weight and absorption. The slump test was used to determine workability. The concrete's behaviour with BFs was studied using scanning electron microscopy. Experimental work of concrete mixtures with BFs of various lengths (12 mm, 25 mm, and 35 mm) and VFs (0%, 0.5%, 1.0%, and 1.5%) were carried out. The samples did not indicate any agglomeration of fibres or heterogeneity during mixing. The addition of BFs to concrete with VFs of up to 1.50% for all fibre lengths have a significant impact on mechanical properties, also the longer fibres performed better than shorter ones at all volume fractions of BFs. The mix10, which contain BFs with VFs 1.5% and length 35 mm, demonstrated the highest mechanical properties. The compressive strength, splitting tensile, flexural strength, and bond stress of the mix10 were 37.71 MPa, 4.27 Mpa, 6.12 MPa, and 6.75 MPa, an increase of 7.37%, 20.96%, 24.13%, and 11.2% over the reference concrete, which was 35.12 MPa, 3.53 MPa, 4.93 MPa, and 6.07 MP, respectively. The absorption is increased for all lengths by increasing the VFs up to 1.5%. Longer fibres have lower absorption, while shorter fibres have higher absorption. The mix8 had the highest absorption of 4.52%, compared to 3.12% for the control mix. Furthermore, the microstructure of concrete was improved through improved bonding between the fibres and the matrix, which resulted in improved mechanical properties of the composite.

• 한국지반환경공학회 논문집
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• 제14권6호
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• pp.39-46
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• 2013

지반개량분야에서는 수많은 공법들이 지금까지 발전을 거듭하여 개발되어왔다. 그러나 대부분의 공법들은 지반의 강도 증진에만 중점을 두었으며 환경문제 발생에 대한 구체적인 해결방안을 제시하지 못하고 있다. 이에 최근에 들어 친환경적으로 지반의 강도를 증대시키는 방법으로 유기산 재료를 이용한 지반개량이 개발되어왔으나 아직 근본적인 안정화 메커니즘에 대해서는 잘 알려지지 않았다. 따라서 본 연구에서는 친환경 개량재인 유기산 재료를 활용한 일축압축강도시험 및 pH시험을 통해 안정화 메커니즘에 대해 규명하였다. 그 결과, 유기산 처리가 된 샘플이 유기산 처리가 되지 않은 샘플보다 시간에 따른 더 큰 일축압축강도를 보였다. 또한, 유기산 재료에 의해 미생물들의 증식이 촉진되며, 토양의 공극 감소를 통해 토양이 개량된다는 것을 규명할 수 있었다. 향후 유기산 재료를 활용한 지반개량 공법의 지속적인 연구가 필요하다고 사료된다.

• Journal of the Korean Wood Science and Technology
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• 제50권6호
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• pp.375-391
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• 2022

Improving public awareness of wood is crucial for expanding the use of wood and establishing a wood culture. In this study, the environment and trends of the public's wood utilization were analyzed using a questionnaire survey and online text mining at a time when eco-friendly practices are gaining popularity. As a result of reducing climatic and environmental concerns and its positive physical and psychological effects, the use of wood is predicted to rise in areas intimately connected to everyday living, such as wood furniture, wooden structures, and interior materials. Nonetheless, there was a negative awareness that wood was expensive, difficult to maintain, and associated with deforestation. The correlations between wood-related search terms on major Korean portal sites were analyzed and categorized into five groups: Wooden architecture, cultural education, woodworking, wood industry, and wood policy. As a building material, wood was seen as more traditional and friendly than reinforced concrete and stone. Eighty-six percent of respondents expected to utilize wood as a building material in the future, regardless of whether the wood is domestically produced or imported. Sixty-five percent responded favorably about the effects of wood on the health of wooden home inhabitants. It is believed that both active publicity and quantifiable value analysis of human and environmental friendliness are required to increase pro-environment awareness of wood utilization.