• Journal of the Korea Institute of Building Construction
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• v.19 no.4
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• pp.323-330
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• 2019

The cement industry is considered a major industry for reducing greenhouse gases, increasing the amount of binding materials that can replace cement in concrete is known as the most effective method for reducing carbon dioxide. Therefore, research is being carried out to utilize large quantities of by-products that can be used as alternatives to cement. However, there are problems with reduced strength at early age and retarded setting for major reasons that do not increase the amount of mixture of binders used to replace cement. Thus, in this study, normal cement and high-fineness cement were used and physical properties were reviewed by placing differences in fly ash usage depending on the type of cement. As a result, the characteristics of strength were similar, and the hydration temperature was the same level. Also, the durability test showed that the length change, carbonation resistance were better than those of normal cement. Therefore, it is confirmed that the use of high-fineness cement is effective to reduce the amount of cement used and using more by-products.

• Resources Recycling
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• v.31 no.6
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• pp.3-17
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• 2022

The cement industry, which is an energy-intensive and high carbon dioxide emission industry, requires strategy for carbon neutrality and sustainable development. Most domestic cement companies are generating electricity by waste heat recovery system to improve energy efficiency during cement processes; however, few studies exist on recycling of energy related to this. Certain countries with high cement production researched on modifying the conventional waste heat recovery system to maximize waste heat recovery using various methods such as applying the Rankine cycle depending on the temperature, comparing working fluids, applying two or more Rankine cycles, and combining with other industries. In this study, we reviewed the research direction for energy efficiency improvement by summarizing waste heat recovery and utilization methods in the domestic and overseas cement industries.

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

• Magazine of RCR
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• v.14 no.1
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• pp.22-28
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• 2019

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.89-94
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• 2003

Recently, the study to reduce and recycle industrial waste is underway vigorously in the various fields of industry according to the conservation of environment and resources. In construction work, the disposal problem of its waste and environmental disruption have already been serious all over the world. However the recycle of waste concrete is still at an early stage, recycled aggregate from waste concrete have only used those as subsidiary road fillers. The research institute and the company make the study that it is about the properties of recycled aggregate and those structural capacity since 1990. Through the experimentation last year, we know that strength and fluidity of recycle cement are inferior to normal cement, and admixing aggregate powder deteriorates its strength. The purpose of this study is to search for appropriate heating time and to improve performance of the recycle cement while heating hardened cement which is crushed, we investigate separating aggregate from hardened cement by preheating and improvement of strength and fluidity inrecycle cement which contains admixture.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.79-80
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• 2023

After the Second Industrial Revolution, as global warming caused by environmental issues has intensified, the CO₂ emissions from the cement industry have become an urgent challenge. Therefore, this study aimed to reduce and utilize CO₂ emissions by using CO₂-reducing Calcium Silicate Cement.

• Clean Technology
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• v.16 no.3
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• pp.182-190
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• 2010

The feasibility of clean technology to minimize the $CO_2$ emission by recycling and reuse the waste materials and energy have been studied for the cement industry. A life cycle assessment (LCA) was performed for an alternative raw material-supply method to use the molted slag as the major raw material in the cement clinker manufacturing. Using this new method, a 60% of $CO_2$ could be reduced that comes out during the decarboxylation from the cement rotary kiln. The energy-efficiency improvement and the alternative energy methods that had been determined in our previous study through the environmental assessment of cement industry were applied to the study for the reduction of $CO_2$ emission. The natural gas, one of the fossil fuels, was also used as the first choice to get the result at the earliest time by the most economic and the most efficient green technology and to switch into the carbon neutral energy consumption pattern.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.595-598
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• 2005

Recently, owing to the development of industry and the improvement of building techniques, the concrete structure is becoming larger and higher. In hardening these large concrete, the heat of hydration gives rise to considerable thermal stress depending on the size and environmental condition of concrete, which might cause thermal cracking. Especially, the crack may cause severe damage to the safety and the durability of concrete structure. This study is investigated the thermal properties of concrete according to several binder conditions, such as OPC, Belite rich cement(BRC), slag cement(SC), blast furnace slag (BFS) added cement, fly ash added cement and BFS-fly ash added cement. As a result of this study, the concrete made with BRC, fly ash($25\%$) added cement and BFS($35\%$)-fly ash($15\%$) added cement gets superior effect in the control of heat hydration.

• Advances in concrete construction
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• v.5 no.2
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• pp.101-115
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• 2017

Cement kiln dust (CKD) is one of the most important waste materials in the cement industry. The large amount of this material, has encouraged researchers to propose new ways to recycle and reuse it. In this paper, effects of adding cement kiln dust to the ordinary Portland cement, on the physical and mechanical properties of ordinary and lightweight concrete were investigated. Results showed that concrete containing CKD, presents lower workability and modulus of elasticity; however, improvements in strength was observed by adding particular amounts of CKD. Eventually, it was found that adding 10% of cement weight CKD is the appropriate percentage for utilizing in manufacturing ordinary and lightweight concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.19-20
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• 2022

Portland Limestone Cement (PLC) is a blended cement using limestone powder as SCMs (Supplementary Cementitious Materials), and is currently regarded as an essential means for achieving carbon neutral in the cement industry. This study was performed to investigate the fresh and hardened properties of cement mortar according to the fineness and replacement ratio of limestone powder. As a result, the compressive strength of mortar used high blaine limestone powder were equivalent level of that of OPC.