• Advances in concrete construction
• /
• v.12 no.5
• /
• pp.419-427
• /
• 2021

The overuse level of cement for civil industry has several undesirable social and ecological consequences. Substitution of cement with industrial wastes, called by-products, such as fly ash, ground granulated blast furnace slag, silica fume, metakaoline, rice husk ash, etc. as the mineral admixtures offers various advantages such as technical, economical and environmental which are very important in the era of sustainability in construction industry. The paper presents the experimental investigations for assessing the mechanical properties of the concrete made using the Pozzolanic waste materials (supplementary cementitious materials) such as fly ash and silica fume as the cement replacing materials. These materials were used in eight trial mixes with varying amount of ordinary Portland cement. These SCMs were kept in equal proportions in all the eight trial mixes. The chemical admixture (High Range Water Reducing Admixture) was also added to improve the workability of concrete. The compressive strengths for 7, 28, 40 and 90 days curing were evaluated whereas the flexural and tensile strengths corresponding to 7, 28 and 40 days curing were evaluated. The study corroborates that the Pozzolanic materials used in the present investigation as partial replacement for cement can render the sustainable concrete which can be used in the rigid pavement construction.

• Journal of environmental and Sanitary engineering
• /
• v.17 no.3
• /
• pp.60-66
• /
• 2002

Iksan city is planning to construct a waste incinerator on the site of about $110,000\textrm{m}^2$ in size that will be selected from a public bid(Oct.~Nov.2002)in the wake of expiration by June 2003 of use for Hamyeol fill-up ground. Science it has usually been difficult to find sites for filling-up or incinerating facilities owing to NIMBY phenomenon, it is badly requested to employ up-to-date technology for processing wastes without environmental pollution. The conflicts between the administrative authorities and community people with regard to construction of incineration facilities, fill-up ground and facilities for waste processing or recycling are not the matters of just today but are increasingly deepening and spreading countrywide. There seems to be no prospect for these conflicts to be amicably settled through dialogues. They rather become a social disease inflicting the whole country like an epidemic. It is therefore believed to be necessary to introduce measures to design and build environment-friendly facilities that may be accepted by residents as not abominable ones but be used as amusing place while they watch the daily operation of them as watchdogs. Iksan city's plan to construct environment-friendly waste incineration facilities of pyrolysis type without chimney has undergone the process of public hearings and explanatory gatherings from every class of Iksan citizens to get consensus but is still delayed due mainly to be the failure of inducing foreign investments. Pyrolysis technology has two advantages ; first, environment-friendly due to less emission of second pollutants ; second, production of by-products highly valuable as resources. It Is known that Germany has recently begun installation and operation of pyrolysis facility urban wastes, an evidence indicating that pyrolysis method will be widely applied to cope with the tightened regulation to preserve environment worldwide.

• Journal of environmental and Sanitary engineering
• /
• v.23 no.3
• /
• pp.59-71
• /
• 2008

In this study, we intend to present the uncontrolled landfill maintenance plans by diversely reviewing the operating conditions of landfill and environmental effects and economical issues resulted from the operation of landfill for the purpose of suggesting the optimal maintenance plans applicable to the uncontrolled landfill and unused landfill located in Korea. We perform the basic and precise surveys against three landfill sites showing the biggest problem out of 8 unsanitary landfills sites located in Y County. We compare and review the treatment plans prepared and operated by the N Landfill. The compared and reviewed results show that the local stabilization plan is more effective than the excavation and transfer treatment plan when considering the economic efficiency only. However, the excavation and transfer treatment plan is valid when considering the diverse elements. The G Landfill is operated with separated into living waste landfill section and construction waste landfill section. However, some landfill gas collection bores or holes are installed in its living waste landfill section, which has not been used for about 20 years, as a part of follow-up control. The element causing the environmental damage is considerably reduced in its living waste landfill section. However, the effort to keep the follow-up control through the local stabilization work is required. The landfill is under processing in the construction waste landfill section. However, most of buried wastes are the inorganic wastes such as waste materials and concrete, so the maintenance plan focused on the use of top land by installing the local stabilization facilities is considered as an effective plan. The landfill is under processing in the K Landfill. It seems to be difficult to maintain this landfill through the local stabilization. The excavation and transfer treatment plan to completely remove the potential environmental pollution source is considered as the valid plan.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.524-531
• /
• 2003

The usefulness of vitrification technology for low- and intermediate- level radioactive wastes was demonstrated because of high volume reduction, mechanical and chemical stability of final waste forms. Thus, a construction of the commercial vitrification plant Is currently promoted. Due to the high radiation level of the waste, shielding analysis has to be carried out for safe design in a vitrification facility. Because there has been no experience in the construction and operation of the vitrification facility in Korea, in this study, in order to get some information for help the detailed design and plan for operation in vitrification facility, shielding analysis for each facility in pilot plant is carried out by using source term from established study. For the selection of the shielding material, concrete was chosen compared to the lead because of economic advantage, weight consideration, and thermal resistance.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.3
• /
• pp.75-81
• /
• 2009

The industrial by-products market has increased at a geometric rate worldwide with the rapid economic growth. Among the wide variety of industrial by-products, fly ash which is generated by the combustion of coal is one of the more troublesome industrial wastes because they entail substantial disposal cost and also cause a shortage of disposal sites. In Korea alone, fly ash generation is expected to increase to 5.8 million tons by 2009, and to 6 million tons by 2010. Given the accelerated industrial development in developing countries, the amount of fly ash generation is predicted to reach enormous levels throughout the world. An increasing number of studies have currently focused on the feasibility of recycling industrial wastes i.e., fly ash in terms of environmental advantages. In this study, the optimized mix proportion of high performance shotcrete using fly ash was determined for the purpose of promoting recycling and reuse of resources.

• Korean Journal of Construction Engineering and Management
• /
• v.23 no.1
• /
• pp.73-82
• /
• 2022

Waste paint, one of the specified wastes in Korea, is currently treated entirely by incineration treatment method, and is hardly recycled compared to other wastes. Incineration treatment method also causes environmental problems such as air pollution. Thus, this study breaks away from the existing incineration treatment method of waste paint and switch to a method of pretreatment operation through evaporation, condensation, and thermal decomposition by temperature control. and then proposes a sustainable waste paint treatment process that can be recycled as an alternative energy heat source. If a new method of disposing of waste paint and technology for recycling are developed and disseminated, it is expected that the effect will be large from an economic and environmental point of view.

• Advances in concrete construction
• /
• v.14 no.1
• /
• pp.1-13
• /
• 2022

Due to the physical-chemical characteristics of some bottom ash (BA), there are technical, economic and environmental limitations to find a destination that will add value to it. In Brazil, this residue is eventually used for filling coal extraction pits or remains in sedimentation ponds, creating a susceptible panorama to environmental issues. The geopolymers binders are one of the alternatives to the proper use high amounts of these materials. In this work, geopolymeric binder pastes were produced with BA mixed to activators with different alkali contents (expressed as %Na₂O), as well as the incorporation of soluble silicates (Ms content). The production of binary geopolymeric pastes based on the use of two industrial wastes: fluid catalytic cracking (FCC) and aluminum anodizing sludge (AAS), was also assessed. The content in mass of BA/FCC and BA/AAS ranged from 100/0, 90/10; 80/20 and 70/30. Systems with soluble silicates as activator in a molar ratio SiO₂/Na₂O of 1.0 (Ms = 1.0) and Na₂O content of 15%, showed the best results of mechanical strength (42 MPa at day 28^th). The improvement is up to 5X when compared to NaOH based systems. For systems with partial replacement of BA of 10% of AAS and 20% of FCC (80/20), the presence of soluble silicates was also effective to increase compressive strength.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.11 no.3
• /
• pp.267-275
• /
• 2023

The cement industry has been contributing to solve the wastes problem by using various combustible wastes as alternative fuel to replace natural coal. To use more alternative fuels such as waste plastics, in the cement manufacturing process, it is necessary to stably burn alternative fuels and reduce air emissions such as NOx. This study is a case study on the multi-stage combustion calciner process, which is a technology that decreases the amount of NOx while increasing the use of alternative fuels. This study is a case study on the multi-stage combustion process, a technology that reduces the amount of harmful air emissions such as NOx while increasing the use of alternative fuels. Along results of comparing before and after applying the technology to actual cement manufacturing facilities, the amount of coal consumption decreased by 38 %, waste plastics consumption increased by 122 %, and NOx emissions decreased by 17 %. Results show that increasing the use of alternative fuels and reducing NOx emissions by multi-stage combustion is effective.

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.4
• /
• pp.100-108
• /
• 2010

With the rapid economic growth and improvement of living conditions in Korea, rebuilding and redevelopment of existing houses has also been rapidly increasing. As a result, considerable construction and demolition wastes have been produced. Demolition wastes, however, must be given special attention because of the various harmful substances in them. The construction waste has been produced most at demolition phase, but the research into that area has not being to make nearly within the country. The aim of this study was to evaluate and compare the contamination figures of the heavy metals and toxin organic substances in the soil and water caused by flying ashes generated and eventually accumulated in building demolition works. AB a result. most of the pollution levels were not worrisome, but some were increased after the demolition with the water used to prevent the dusty air and in the target buildings. However in the vicinity of the demolition sites with explosives there was no report of study in water and soil pollutions, so to minimize pollutions we need to make plans to select the harmful substance in the first place. Thus, this research is expected to be the important materials for future research into the construction waste area.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2002.11a
• /
• pp.77-86
• /
• 2002

In this study we intended to investigate properties of cement mortar with recycled PET fiber, PE fiber, and PP fiber such as slump flow, compressive strength, tensile strength, and flexural strength. As results of experiment, several properties of specimen with recycled PET fiber were little low comparing those of specimen with PE fiber and PP fiber. But if we see from point of economy and recycle of industrial wastes, it has enough reason to be used. Compressive strength of specimen with recycled PET fiber at 56 days was about 10% higher, but tensile strength and flexural strength were lower than that of no-fiber.