• Advances in concrete construction
• /
• 제15권1호
• /
• pp.63-74
• /
• 2023

All production and consumption activities produce wastes, which often cause damage to our environment and multiple risks to the human health. The valorization of these wastes in concrete technology is a future solution that will allow finding other construction materials sources, optimizing energy consumption and protecting the environment. Among these wastes, there is the marble waste. Every year, huge amount of marble waste is discarded as dust or aggregates form, in open-air storage areas causing serious problems for the environment and public health. In this context, the incorporation of marble waste as a replacement of ordinary aggregates or cement in concrete composition is actively investigated by researchers. This paper presents a comprehensive review of published studies over the last 20 years, dealing the effect of marble waste on fresh and hardened properties of concrete. Most of the studies carried out have used marble waste as dust with substitution rates between 5 and 20%. Besides the economic and ecological benefits, this review showed that marble waste can improve the physical, mechanical and durability properties of concrete. This improvement depends on the form (dust, fine aggregate or coarse aggregate), substitution method (as cement or aggregates replacement) and substitution rate of marble waste. Additionally, the review results showed that the use of 10-15% of marble waste dust as cement substitution can lead to increase the compressive strength.

• 한국환경복원기술학회지
• /
• 제13권3호
• /
• pp.63-72
• /
• 2010

This study was conducted to investigate the current status and the improvement plans of the ecosystem conservation fund return projects. In 2007, there was a reformation of the ecosystem conservation fund system but the fund return projects were not vitalized up until now. In this study, 35 of ongoing and finished fund return projects were investigated on their types, sites, costs, local governments, and time required to return the fund. Through the on-site survey of 9 finished projects (4 biotope, 2 corridor and 3 natural conservation facility projects), construction and management conditions were investigated. The main findings are as follows: Among the five fund return types, 17 cases were biotope restoration projects, 4 cases were ecological corridor projects, and 1 case was a nature replacement project. In the case of project sites, there were 14 cases near schools and public facilities, 8 cases near rivers or streams, and 2 cases near ponds or wetlands. For the construction costs, there were 19 cases (65% of all the projects) that cost less than 300 million won. In terms of the involvement of the local government, most of the fund return projects were concentrated in Gyeonggi province and Ulsan city, and there were some local governments outside of these regions that did not carry out any return projects at all. Lastly, in the case of fund return time required, 35% of the fund returns were completed within 5 months, but the overall average fund return time was 9.8 months. In respond to the above study results, the improvement plans to encourage fund return projects are as follows: To diversify return types and sites, piloting and modeling projects for the representative types and sites should be preceded. To emerge from customary small-scaled projects, incentives to encourage large-scale and ecological networking projects should be considered. In addition, in order to write up business plans for the fund return projects, long-term investigations of at least 2 seasons from spring to fall are necessary. Finally, for the continuous management and maintenance of the ecological fund return sites, easier way for the citizens to actively participate in the projects should be incorporated.

• 한국응용곤충학회지
• /
• 제57권4호
• /
• pp.323-328
• /
• 2018

외래침입종이 자생종에 미치는 잠재적인 영향에 관하여 세계적인 관심이 증가하고 있음에도 그러한 침입의 결과들은 여전히 부족한 실정이다. 유럽좁쌀바구미(cabbage seedpod weevil, CSPW, Ceutorhynchus obstrictus)는 1990년대 초에 한반도에 침입하였다. 침입 후 20여 년 동안 관찰과 2010년 이후 중점적인 조사를 통해 유채 꽃에서 침입종인 유럽좁쌀바구미가 가장 우점을 이루고 있으며, 제주도와 울릉도를 포함한 남한 전역으로 확산되어 있다. 그의 확산은 자생종인 유채좁쌀바구미(rapseed weevil, RSW, C. albosuturalis)의 냉이 등 십자화과 잡초로 서식처 후퇴가 맞물려 일어나고 있다. 한편, 한반도와 제주도 사이에 위치한 여서도는 현재 그들의 비율이 약 1:1로 나타나고 있어 이 섬에는 유럽좁쌀바구미가 최근에 유입된 것으로 보인다. 자생종의 생태적 지위(ecological niche)가 외래침입종으로 대체되는 근본적인 기작은 확실하게 알 수 없지만, 자원경쟁(exploitative competition)의 잠재적인 역할을 배제할 수는 없을 것이다. 자연생태계 내에서 외래침입종이 자생종을 신속하게 대체하고 있음을 확인한 이 결과는 앞으로 또 다른 외래종의 침입 방지 노력을 요구하고 있다.

• International Journal of Concrete Structures and Materials
• /
• 제9권2호
• /
• pp.241-254
• /
• 2015

A lot of reinforced concrete (RC) structures in Syria went out of service after a few years of construction. This was mainly due to reinforcement corrosion or chemical attack on concrete. The use of blended cements is growing rapidly in the construction industry due to economical, ecological and technical benefits. Syria is relatively rich in scoria. In the study, mortar/concrete specimens were produced with seven types of cement: one plain Portland cement (control) and six blended cements with replacement levels ranging from 10 to 35 %. Rapid chloride penetration test was carried in accordance with ASTM C 1202 after two curing times of 28 and 90 days. The effect on the resistance of concrete against damage caused by corrosion of the embedded steel has been investigated using an accelerated corrosion test by impressing a constant anodic potential. The variation of current with time and time to failure of RC specimens were determined at 28 and 90 days curing. In addition, effects of aggressive acidic environments on mortars were investigated through 100 days of exposure to 5 % $H_2SO_4$, 10 % HCl, 5 % $HNO_3$ and 10 % $CH_3COOH$ solutions. Evaluation of sulfate resistance of mortars was also performed by immersing in 5 % $Na_2SO_4$ solution for 52 weeks. Test results reveal that the resistance to chloride penetration of concrete improves substantially with the increase of replacement level, and the concretes containing scoria based-blended cements, especially CEM II/B-P, exhibited corrosion initiation periods several times longer than the control mix. Further, an increase in scoria addition improves the acid resistance of mortar, especially in the early days of exposure, whereas after a long period of continuous exposure all specimens show the same behavior against the acid attack. According to results of sulfate resistance, CEM II/B-P can be used instead of SRPC in sulfate-bearing environments.

• 한국환경복원기술학회지
• /
• 제14권1호
• /
• pp.11-22
• /
• 2011

This study was established to build and suggest the Ecological Performance Standards for replaced wetlands as the mitigation strategies for the construction projects. The request performance and assessment factors and standards were derived by bibliographic review and verified by the field survey for the reference wetlands. And the weights for each factor were derived by AHP(Analytical Hierarchy Process) method. The results are as follows : 1) Assessment factors were induced by in-depth research of many wetland assessment models and benchmarks evaluated ecological functions. This study proposed final 12 assessment factors through ecological specialist and experts interviews added with literature analysis. 2) 10 natural wetlands were selected as Reference Wetlands as the measure to propose assessment factors and assessment criteria. Those reference wetlands are well-conserved inland natural wetlands classified to the one having worthy to conserve (grade "high") according to RAM(Rapid Assessment Method). Reference wetlands chosen by the study are Parksilji, Jeongyangji, Mulkubi, Bawineupkubi, Jilnalneup, Jinchonneup, Doomoso, Haepyung wetland, Whangjeong wetland, and Whapo wetland. The research developed assessment criteria for the performance assessment factors based on several explorations of the reference wetlands. 3) "Requiring performance" of replaced wetlands is defined as "to carry out similar or same ecological functions provided by natural wetlands", in overall. The detailed requiring performances are as follows; ${\bullet}$ to play a role of wildlife habitats ${\bullet}$ to have biological diversity ${\bullet}$ to connect with other ecosystems ${\bullet}$ to provide water environment to perform good ecological functions 4) The assessment factors for required performance are categorized by wildlife habitat function, biological diversity, connectivity of adjacent ecosystem, and water environment. Wildlife habitat category is consisted of wildlife habitat creation, size of replacement wetland, and site suitability. Biological diversity category contains the number of plant species, the number of wildlife species, and number of protected species as the sub-factors. Connectivity of adjacent ecosystem is comprised of wildlife corridor, green network and distance from other ecosystem. Finally, water environment make up with water quality, depth of water body, and shape of waterfront. 5) Finally, every assessment factors were verified and weighted by the AHP methods and the final standards were proposed. The weights of factors of requiring performance suggested as habitat (0.280), connectivity (0.261), diversity (0.260), hydraulic environment (0.199). And those of detailed sub-factors are site suitability (0.118), protected species (0.096), distance to neighbor ecosystem (0.093), habitat creating (0.091), green corridor (0.090) etc.

• 한국조경학회지
• /
• 제32권1호
• /
• pp.104-126
• /
• 2004

The recognition of the environment and its importance have generated various types of parks, such as the ecological put the environmental put and the natural academy. They are considered the connecting media for the creation of space as a new paradigm in design for the 21st century from the late 1990s, environmental designs in space planning have been created from various angles of Perspectives including restoration of the natural ecosystem and introduction of natural circulation systems. Based on the aye facts and through theoretical examination of environmental park models, this research (1) establishes the concept and the significance of environmental parte; and, based on this, classifies the types of industrial sublimity; (2) presents environmental designing principles and standards; and (3) presents the "Chung Ra pro-Environmental Park plan" based on these ideas. The following is the summary of research results: First, while existing city parks are human-oriented, interior-oriented, and shape-centered, an environmental park considers human and nature equally and gives great importance to the relationship between the internal and external of the subject. It is a mark of environmental education that considers the natural ecosystem. Therefore, the environmental park is the 21st Century′s type of an open park for creating new forms of nature, as well as for incorporating culture and values through education. In such an environmental system, nature, culture, and human beings pursue balance, harmony, and security through mutual recognition. Second, in a broad sense, the types of environmental park can be classified into Cultural Restoration, Ecological Conservation, and Environmental Replacement. Third, by selecting Chung na environmental park in Incheon, which is a filtration plant lot, as a research subject, I have presented alternative planning for environmental parte in which culture and nature coexist on the basis of environmental planning principles and standards.

• Journal of Ecology and Environment
• /
• 제31권3호
• /
• pp.213-223
• /
• 2008

The increasing area of abandoned rice fields could provide new opportunities for wetland restoration in Asia. However, it is unknown how quickly or completely abandoned rice fields will recover from agricultural disturbances. We assessed water quality and plant community succession in abandoned rice fields with different hydrology in a mountain valley to understand the effects of hydrological regime on recovery. Water level, soil redox potential, water quality, plant composition, and primary production were measured. The sites, coded as D6, N13, and N16, had been recovering for 6, 13, and 16 years by 2006. N13 and N16 have been recovering naturally whereas D6 has been drained with a nearby dike and was tilled in 2001. The typical hydroperiods of D6, N13, and N16 were no surface water, permanently flooded, and seasonally flooded, respectively. The major change in vegetation structure of both D6 and N13 was the replacement of herbaceous species by woody species. Drawdown accelerated this change because Salix koreensis grew better in damp conditions than in flooded conditions. Phragmites japonica reduced plot-level plant species richness. The removal efficiency of $NH_4-N$, $NO_3-N$, and $PO_4-P$ from water varied seasonally, ranging between -78.8 to 44.3%, 0 to 97.5%, and -26.0 to 44.4%, respectively. In summary, abandoned rice fields quickly became suitable habitat for native wetland plant species and improved regional water quality. Variation among our sites indicates that it is likely possible to manage abandoned rice fields, mostly through controlling hydrology, to achieve site-specific restoration goals.

• 한국환경복원기술학회지
• /
• 제26권6호
• /
• pp.221-234
• /
• 2023

This study was conducted to develop a habitat assessment system for the endangered wildlife II Kirengeshoma koreana Nakai through in-depth interviews with experts based on field surveys and environmental characteristics through spatial data analysis and literature research. Evaluation factors were selected based on the survey results of 31 variables for 23 K. koreana habitats. Afterwards, the importance and evaluation range for each assessment factor were selected. The selection of survey variables, assessment factors, importance of each factor and assessment range was conducted through in-depth interviews with experts at each stage. As a result, the assessment factors and importance were 16% for precipitation of the wettest month, 10% for vegetation zone, 12% for vegetation type, 10% for crown canopy vitality, 14% for tree layer coverage, 13% for drainage grade, 12% for soil depth, and 13% for distance to stream including dry stream. This study provides basic ecological information and a habitat assessment system for K. koreana habitats. Therefore, it can be used as primary data for preparing an endangered wildlife conservation policy, preparing a habitat improvement plan, and selecting an alternative habitat.

• 한국콘텐츠학회논문지
• /
• 제14권11호
• /
• pp.236-248
• /
• 2014

본 연구의 목적은 노인의 인적, 사회적, 문화적 자본 및 생태환경 요인이 노인들의 자원봉사활동에 미치는 영향을 탐구하는데 있었다. 본 연구에서 인적 자본 변수는 학력, 소득 및 신체적 건강의 세 변수를, 사회적 자본 변수로는 비공식적 상호작용과 공식적 상호작용의 두 변수를, 문화적 자본 변수로는 종교, 문화단체참여 및 삶의 질의 세 변수를 그리고 생태환경변수로는 배우자 유무, 주택점유형태 및 거주지역의 세변수를 사용하였으며, 종속변수인 노인자원봉사 변수로는 자원봉사 참여여부 및 지속적 자원봉사 참여의도의 두 변수를 검토하였다. 본 연구를 위한 자료는 노인인력개발원에서 수집한 "2012년도 노인일자리사업참여노인 실태조사" 자료를 사용하였으며, 주된 자료분석방법으로는 로짓회귀분석을 사용하였다. 본 연구결과 인적 자본 요인들인 학력, 소득, 및 신체적 건강은 자원봉사 참여여부와 지속적 자원봉사 참여의도에 모두 긍정적인영향을 미치고, 사회적 자본 요인들 중에서 비공식적 상호작용은 자원봉사 참여여부와 지속적 자원봉사 참여의도에 영향을 미치는 반면에 공식적 상호작용은 지속적 자원봉사 참여의도에만 긍정적인영향을 미치며, 문화적 자본 요인들인 종교, 문화단체참여 및 삶의 질은 자원봉사 참여여부와 지속적 자원봉사 참여의도에 모두 긍정적인영향을 미치는 것으로 나타났다. 마지막으로 생태환경 요인들 중에서 주택점유형태와 거주지역은 자원봉사 참여여부와 지속적 자원봉사 참여의도에 긍정적인영향을 미치는 반면에 배우자 유무는 모두 영향을 미치지 않는 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
• /
• pp.11-16
• /
• 2002

The production of Portland cement involves maximum use of resources and energy, which leads to destruction of tile ecological environment, raising in serious environmental issues such as acid rain and the greenhouse effect. In order to combat the arising problems associated with Portland cement, it thus is necessary that a non-clinker cement should be developed. In this study, non-clinker cement is produced by blending granulate blast furnace slag with phosphogypsum as main materials, and small amounts of hydrate lime or waste lime as activators. This paper aims to investigate compressive strength according to various condition of mixing ratio, blame, W/C ratio and curing temperature. Compressive strength of non-clinker cement increases continuously according to increase in curing age and blain. Although the compressive strength is fairly comparable to that of OPC in the early curing age, it reaches a higher lever in the later age than that of OPC due to the optimum mixing ratio and the continuous reaction of slag and phosphogypsum. Results obtained from this study have shown that non-clinker cement could be used as a replacement of OPC.