• Advances in concrete construction
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• v.17 no.4
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• pp.211-220
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• 2024

Concrete, consisting mainly of cement, water and aggregates; is the most used construction material all over the world. Cement manufacturing industry is one of the carbon dioxide producing sources that contributes to global warming. Therefore, in the last few years, there is a growing interest in using waste materials and by-products as cement replacement materials. Using these kinds of materials as a part of cement replacement reduces the air pollution, cost and also enhances some properties of concretes. In the present work, marble dust (MD) was examined as a partial cement replacement material with seven proportions as 0%, 10%, 20%, 30%, 40%, 50%, 60% and glass powder (GP) was used as an additive, 8% by cement weight, in a 0.55 water-binder ratio concrete. In order to evaluate their effects; workability, strength (compressive, flexural and split tensile), alkalinity, sulphate resistance and ultrasonic pulse velocity tests were performed. Experimental results indicated that with MD replacement and GP addition; there is a loss in the workability but improvement in mechanical properties. With 10% replacement of MD compressive, flexural and tensile strengths increased by 10.7%, 6.2% and 5.3% respectively. Moreover, up to 30% replacement of MD reasonable strength values were obtained.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.465-474
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• 2022

Research on the recycling of waste concrete has been conducted mainly focusing on the production of high-quality recycled ag g reg ate, and as a result, standards and specifications for recycled ag g reg ate have been established. However, in the case of waste concrete powder, although a lot of research on its utilization has been conducted in Korea, an innovative technology leading to commercialization has not yet been announced. Recently, research on technology using waste concrete powder as a raw material for clinker or cement has been actively conducted in major overseas advanced countries. This study investigated the overseas cases with regard to high value-added recycling technology and commercialization trend of waste concrete powder for carbon neutrality in cement and concrete industries. A number of studies have reported that it is essential to completely separate the aggregate and hydrated cement paste fraction for recycling of waste concrete powder. Also in major foreig n countries such as EU and USA, commercialization and standardization of using waste concrete powder as a raw material for clinker or a additive for cement are now in progress beyond the R&D stage. Therefore, Research and standardization for recycling of waste concrete powder should be urgently carried out from the perspective of carbon neutrality in Korea.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.95-97
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• 2012

Recycled aggregate (RA) produced from demolished concrete waste can bring about several problems on concrete performance, when it is used as aggregate for new concrete. Because RA generally has lower quality than natural aggregate due to the residual cement paste attached on RA and various impurities. It is also very difficult to ensure that the quality of RA remains consistent, because generally RA is produced variously. Thus, in concrete recycling, it is extremely important to estimate the risk of the impurities which could affect performances of recycled aggregate concrete (RAC) focusing on the material flow of concrete waste and its recycling. This study suggests an evaluation result to expect the possibility of impurity mixing in RA production procedure. and suggests a risk evaluation model to expect the changes of RAC performances based on conventional data in Japan.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.271-273
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• 2012

This paper is to investigate the effect of waste cooking oil(WCO) on carbonation resistance of high volume fly ash and blast furnace slag concrete. WCO and paint were applied for carbonation resistance materials. As expected, the application of WCO to the concrete help it reduce carbonation depth remarkably, regardless of mixture types. This may be due to the fact that WCO makes the capillary pore block by activating saponification. It is found that the degree of carbonation reduce due to WCO is much higher than the case by Paint.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.165-166
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• 2018

Researches for the development of renewable energy as a fuel substitute for global warming and depletion of petroleum resources are actively being carried out. Among them, the annual growth rate of PV generation is 20.73%, which is higher than other renewable energy sources. However, the production of 1 ton of polysilicon, which is known as a raw material for solar power generation panels, generates 2 tons of waste. As the demand for PV panels increases, the problem of the treatment of polysilicon sludge is attracting attention, and studies on the utilization of polysilicon sludge are needed. Therefore, in this study, the applicability of polysilicon sludge treated as industrial waste to the lightweight panel for architectural purposes was examined.

• Journal of the Korea Institute of Building Construction
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• v.6 no.4 s.22
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• pp.93-98
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• 2006

Admixture materials are used in mixing concrete or mortar to improve quality and performance of the concrete. This study examines the potential use of talc as a substitute for cement, the benefits of recycling waste resources for economical efficiency and quality improvement of concrete. The test was carried out by replacing the plain mix with fine grains of talc at the rate of 10%, 20%, and 30%. Talc was divided into three groups depending on the degree of pulverizing. For wet concrete, porosity, slump, bleeding per unit, and setting time by penetration resistance were measured; similarly, for dry concrete, strength and watertight Property were tested. Test results showed that the amount of bleeding and setting time could be shortened, but the strength and watertight proofing severely deteriorated. However, at the replacement rate of 10%, talc showed equal performance with the plain at all degrees of pulverization, which suggests its potential use as admixture material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.110-111
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• 2021

The eggshell is a type of bio-waste which is considered hazardous to the environment. In this research, the waste eggshell is utilized as a potential filler in cementitious material. This study has measured by zeta potential to analyze the interaction between the surface of the filler and the calcium ion in the solution. Meanwhile, the effect of eggshell powder on cement hydration process has been determined by isothermal calorimeter. The results show that the surface of eggshell powder have a strong adsorption of Ca2+, and addition of the eggshell powder provides a heterogeneous nucleation site for cement, which promotes the growth of hydration products.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.230-233
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• 2006

국내에서는 매년 60만 톤의 하수슬러지가 준설된다. 현행법상 하수 준설토는 산업폐기물로 정의되며, 재활용되도록 강조되어진다. 그럼에도 불구하고 매입에 의한 처리로 낭비되고 있는 실정이다. 본 연구에서는 하수 준설토의 재활용 방안을 모색하기 위하여 지반 공학적 실험을 실시하였다. 실험 결과 준설된 순수한 하수 준설토의 경우 국내 건설용 성토재료 요구기준에 충분히 안정적인 것으로 나타났다.

• Nuclear Engineering and Technology
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• v.40 no.5
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• pp.429-438
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• 2008

The objective of the present study is the depth and layout optimizations of a single layer, high level radioactive waste repository in a discontinuous rock mass with special joint set arrangements. A single layer repository model, considering variations in the repository depths, pitches, and tunnel spacings, is used to analyze the thermomechanical interaction behavior. It is assumed that the repository is constructed in saturated granite with joints; the PWR spent fuel in a disposal canister is installed in a deposition drift which is then sealed with compacted bentonite; and the backfill material is filled in the repository tunnel. The decay heat generated by the high level radioactive wastes governs the thermomechanical behavior of the near field rock mass of the repository. The temperature and displacement behavior of the repository is influenced more by the pitch variations than the tunnel spacing and repository depth. However, the stress behavior is influenced more by the repository depth variations than the pitch and tunnel spacing. For the final selection of the tunnel spacing, pitch, and repository depth, other aspects such as the nuclide migration through a groundwater flow path, construction costs, operation costs, and so on should be considered.

• Environmental Engineering Research
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• v.21 no.4
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• pp.341-349
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• 2016

To improve the utilization rate of construction waste as mine backfilling materials, this paper investigated the feasibility of using recycled powder as mine paste backfilling cementitious material, and studied the pozzolanic activity of recycled construction waste powder. In this study, alkali-calcium-sulfur served as the activation principle and an orthogonal test plan was performed to analyze the impact of the early strength agent, quick lime, and gypsum on the pozzolanic activity of the recycled powder. Our results indicated that in descending order, early strength agent > quick lime > gypsum affected the strength of the backfilling paste with recycled powder as a cementitious material during early phases. The strength during late phases was affected by, in descending order, quick lime > gypsum > early strength agent. Using setting time and early compressive strength as an analysis index as well as an extreme difference analysis, it was found that the optimal ratio of recycled powder cementitious material for mine paste backfilling was recycled powder:quick lime:gypsum:early strength agent at 78%:10%:8%:4%. X-ray diffraction analysis and scanning electron microscope were used to show that the hydration products of recycled powder cementitious material at the initial stages were mainly CH and ettringite. As hydration time increased, more and more recycled powder was activated. It mainly became calcium silicate hydrate, calcium aluminate hydrate, etc. In summary, recycled powder exhibited potential pozzolanic activities. When activated, it could replace cementitious materials to be used in mine backfill.