• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.5-13
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• 2008

In this study, It was carried out to evaluate the feasibility of recycled crushed concrete as aggregate used cement mortar replace sand and to investigate engineering properties of recycled aggregate for hazardous waste solidification. The compressive strength of cement mortar replaced 5-15% (wt.) recycled aggregate was over $163kgf/cm^2$ which is the standard of first grade concrete block class C. And cement mortar was examined to evaluate the stability by leaching test. Cu, Cd, Pb, Cr, and As as the heavy metals were proved very stable but mercury (Hg) was leached high concentration because it was simply tied to the cement surface. We investigated the crystal structures of cement mortar and they had shown the peaks of $Ca(OH)_2$, ettringite, and CSH (calcium silicate hydrate). As the result, the longer curing time, the higher CSH peak that means to increase compressive strength and the cement mortar was more stable. Therefore it was shown that it may be possible to apply hazardous waste solidification using recycled aggregate, fly ash and sewage sludge ash.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.219-226
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• 2020

Over the last decades, great efforts have been devoted to reuse industrial wastes and by-products from various industries as supplementary cementitious materials in order to reduce carbon dioxide(CO₂) emission by reducing the use of Portland cement in construction. Oyster shell waste, originating from the fishery industry, is available in huge quantities in certain areas, and is generally discarded or landfilled. In this study, we aimed to reuse oyster shell as an alternative to limestone in limestone calcined clay cement(LC³). The oyster shell calcined clay cement(OC³) paste were produced and were characterized via X-ray diffraction, isothermal calorimetry, compressive strength tests, and thermogravimetry. The results revealed that OC³ pastes exhibited similar strength development and reactivities by pozzolanic reaction with LC³, which implies that oyster shell could be used as a substitute for limestone in LC³.

• Archives of design research
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• v.19 no.4 s.66
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• pp.133-144
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• 2006

According to the latest report by the Customer Protection Board, those who moved into newly constructed buildings are complaining about unidentified pains, asking for more careful selection of constructive materials for prevention of such potential problems. It is internationally recognized today that ecological materials can serve a significant factor for users' health, environmental protection and better industrial competitiveness. This study examined eco-design aspects of each interior material through web site search, in order to help customers learn about and capitalize on eco materials in a proper manner. As a result, 1. It turned out that the domestic industry are giving an impetus to releasing new eco items focusing on lower VOCs emission or addition of functional components as part of the marketing strategy. However, it is recommended that company understand significance of life cycle, and produce eco-concept materials. 2. The reliable standard for choosing the domestic material is EL, HB, GR marks. It is desirable to enhance recycling technologies and expand the sustainable consumption. customer class, since many recycled items are not developed. 3. The sourcing is a vulnerable part in terms of the concept of being environment-friendly material. Therefore, many manufacturers should design the easy knock-down products and produce the good items using recycled materials instead of new raw materials. Also solutions for making the energy from burning material should be studied. 4. The guidebook or manual with correct information about eco-materials is required to promote production and consumption with sustainable concept. 5. Many manufacturers are emphasizing ecological materials for customers, but some of them intended to disrupt customers' proper selection by promoting even unverified items to be environment-friendly.

• Journal of the Korea Institute of Building Construction
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• v.11 no.3
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• pp.301-309
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• 2011

Apartment housings that adopt a bearing wall structure design, which account for a majority of the housing units available in Korea, are not free from structural constraints that limit the extension of their service life. The resulting need for reconstruction from the ground up requires a massive consumption of resources and energy, and triggers environmental pollution resulting from construction wastes. As a solution to such issues, the government enforces incentive schemes to promote a remodeling-friendly rahmen structure design. Green Frame, which is a novel concept of composite precast concrete structure to support rahmen structure apartment housing buildings, can address the constraints of bearing wall structure and conventional rahmen structure designs that limit the potential for remodeling projects, while reducing the term of construction. Therefore, this study aims to analyze the characteristics of Green Frame and its absolute term of construction, and compare the terms of frame work construction in apartment housing projects adopting different structural design approaches to illuminate their differences. In the end, Green Frame is found to be capable of reducing the term of construction in apartment housing projects. As the term of construction is a very critical element of a construction project, Green Frame will ultimately prove to be one of the key enablers to ensure the success of apartment housing construction projects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.158-166
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• 2018

Contrary to urban development, urban regeneration is a process of land development through conservation, restoration, and management. In particular, ecologically based urban regeneration is an attempt to improve the quality of life in an area, establish a stable settlement space, and revitalize the local economy by considering the ecological environment. In this regard, the objectives of this study were to establish theoretical concepts and analyze the successful foreign cases of ecologically based urban regeneration, and propose a direction of socio-economic regeneration along with the physical-environmental regeneration of urban areas in Korea. The study results suggest the following. First, strategies must be developed to coordinate public transportation, such as buses and subways, by considering the importance of bicycle riders, along with the sustainable-commuting system. Second, both the importance of planning parks and trails around water systems in various scales while maintaining the existing natural environment as well as using natural elements, such as electric vehicles and wind-power generation systems, were emphasized. Third, urban regeneration for increased energy efficiency requires specific architectural planning and facilities. Fourth, education and research for easy access by the public, as well as public-private partnership, will be needed in the regeneration process.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.531-536
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• 2014

Recently, the amounts of dredge sea soil in south Korea have been increasing because of various maintenance works at harbors and rivers. Dredged sea soil contains various contaminants. Hence, prior to recycling the dredged sea soil, the various contaminants should be removed to prevent a secondary contamination due to the leaching of hazardous chemicals. Pretreated dredged sea soil can be buried under the ground or used for land reclamation. In this study, however, pretreated dredged sea soil was used to investigate the level of pozzolanic activity. The properties of pretreated dredged sea soil were investigated, the method for heat treatment was determined, and the compressive strength of mortar using dredged sea soil was examined. According to the XRF result, the main components of dredged sea soil were $SiO_2$ of over 55%, and $Al_2O_3$ and $SO_3$ of some amounts. Results from XRD and TG/DTA showed that pretreated dredged sea soil can be used as a pozzolanic material. When dredged sea soil was thermally treated for 90 min at $550^{\circ}C$, a compressive strength result was similar to that of control mortar.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.411-418
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• 2017

This study classified oyster shells that produced as a industrial waste into 3 distribution by washing, drying and processing them. Mortar specimens with a constant ratio by using this to substitute fine aggregates were made, and the specimens were heated under the heating conditions of $300^{\circ}C$, $600^{\circ}C$ and $900^{\circ}C$ based on the 28-day age. On the age of 28 days, the plain flexural strength was found to be 9.2MPa, and in O 0.15, it was shown to be 4.4~7.9MPa depending on the substitution rate. It was found to be 4.4~7.7MPa in O 1.2~2.5 depending on the substitution rate, and last but not least, it was shown to be 6.1~8.8MPa in case of O 2.5~5.0 depending on the substitution rate. In case of the compressive strength of the 28-day age, it showed the difference of 23.6~43.2MPa in O 0.15 depending on the substitution rate, and 20.4~45.1MPa in O 1.2~2.5 depending on the substitution rate, and last but not least, 17.1~40.4MPa in case of O 2.5~5.0. As a result of measuring the residual strength through heating, in case of substituting fine aggregates less than O 0.15 by 100%, it showed the lowest strength reduction ratio, and it is expected that the heat-resisting property could be achieved through processing and proper mixing of oyster shells through these results.

• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.419-427
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• 2018

The purpose of this study is to recycle steel slag generated from the iron producing process and to use steel slag as a construction material which is currently landfilled Steel slag is subjected to aging treatment due to the problem of expansion and collapse when it reacts with water. The Slag Atomizing Technology (SAT) method developed to solve these problems of expanding collapse of steel slag. In this study, experimental study on the emergency repair mortar using the reducing slag, electric arc furnace slag and silicon manganese slag manufactured by the SAT method is Reduced slag was shown an accelerated hydration when it was replaced with rapidly-setting cement, and the rate of substitution was equivalent to 15%. It is shown that the electric furnace oxide slag is equivalent to 100% of the natural aggregate, and it can be replaced by 15-30% when the silicon manganic slag is substituted for the electric furnace oxide slag. With the above formulation, it was possible to design the rapidly repair mortar for road use. These recycling slags can contribute on achieving sustainability of construction industry by reducing the use of cement and natural aggregates and by reducing the generation of carbon dioxide and recycling waste slag.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.184-193
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• 2013

Procurement System for Korean construction industry has mainly been controlled by the complicated regulatory system which has been recognized as unflexible and remotely separated from the global standard. This has been identified by many Korean construction experts as one of the main reasons that hamper the Korean construction industry becoming the global leader. One commonly discussed regulatory system is the compulsory multiple contracting system that has been enforced for a long time. According to the Korean governmental contracting law 68-3, all construction projects cannot be divided into separate contracting packages with a few exceptions. Exceptions stated in the law include construction activities related electrical, Information communication, fire-fighting, and cultural assets which all are governed by the separate laws/acts controlled by the different governmental bodies. This research is to closely investigate multiple prime contracting system that has been compulsory in Korean construction industry and to provide policy recommendations to these restrictions. Although, there has been a long history of this compulsory contracting system, this study attempted to provide objective analysis on current status of the system as well as global standard on the issue. This study suggests main considerations when considering different contracting system such as rights of owners, flexibilities of regulatory systems, and efficiencies of conducting a construction project. It is envisioned that recommendations from this study, if accepted by the regulatory bodies, would improve the Korean construction contraction system by making it more compatible with global standard. Moreover, these would help making the Korean industry more effective in terms of regulatory restrictions.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.387-394
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• 2020

In this research, a physical property test of CLSM, which can safely and effectively utilize a great number of industrial byproducts and waste types, was used to review the applicability of GBFS, FNS, and FGB, as well as their field applicabilities as cavity fillers, and the following conclusions have been reached. first, For CLSM utilizing GBFS, FNS, and FGB, it was revealed that a proper mixing of over 30% of GBFS and FNS or within 5% of FGB is effective in improving the fluidity for field application. second, It was revealed that GF15B5 can suppress bleeding at a similar level as the base, whereas GF30B5 can do so at about 0.17% compared to the base. It was also verified that GF15, GF30, and GF45 can suppress bleeding at about 0.2%, 0.26%, and 0.3%, respectively, compared to the base. third, Both GF15B5 and GF30B5 exceeded 0.4MPa in 7day strength tests to satisfy the field application and, also, the rates of increase of their initial strengths were found to be 323% and 233% higher than the base, respectively. Meanwhile, the 7day strength test of GF, which utilizes GBFS and FNS, also reached over 0.2MPa for field application, and it was revealed that GF15, GF30, and GF45 show 160%, 237%, and 185% higher strength increase rates, respectively, compared to the base.