• Advances in concrete construction
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• v.7 no.4
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• pp.263-275
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• 2019

In the present work, Granulated Blast Furnace Slag (GBFS) and Fly ash (FA) were used as partial replacement of Natural Sand (NS) and Ordinary Portland Cement (OPC) by weight. One control mix, one with GBFS, three with FA and three with GBFS-FA combined mixes were prepared. Replacements were 50% GBFS with NS and 20%, 30% and 40% FA with OPC. Preliminary investigation on development of compressive strength was carried out at 7, 28 and 90 days to ensure sustainability of waste materials in concrete matrix at room temperature. After 90days, thermo-mechanical study was performed on the specimen for a temperature regime of $200^{\circ}-1000^{\circ}C$ followed by furnace cooling. Weight loss, visual inspection along with colour change, residual compressive strength and microstructure analysis were performed to investigate the effect of replacement of GBFS and FA. Although adding waste mineral by-products enhanced the weight loss, their pozzolanicity and formation history at high temperature played a significant role in retaining higher residual compressive strength even up to $800^{\circ}C$. On detail microstructural study, it has been found that addition of FA and GBFS in concrete mix improved the density of concrete by development of extra calcium silicate gel before fire and restricts the development of micro-cracks at high temperature as well. In general, the authors are in favour of combined replacement mix in view of high volume mineral by-products utilization as fire protection.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.187-190
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• 1999

An experimental study is carried out to estimate the way of applying the granulated blast furnace slag[GBFS] to the lean concrete base of concrete pavement. According to the test results, this application seems promising. For this application, mixing percent of GBFS ranging from 30 to 50 is recommendable at this stage. And performance of base mixed with GBFS is greatly affected by the curing and placing condition. As long as all requirements for application of GBFS to the base is satisfied, better performance is expected.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.34-35
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• 2015

The purpose of this study is to investigate the compressive strength property of concrete with Ground granulated blast furnace slag(GBFS) using wash water from recycled aggregate. When GBFS is reacted with water, it doesn't happen to hydraulic reaction but GBFS becomes latent hydraulic property in alkaline environment. For this reason, if it is possible to use wash water from recycled coarse aggregate as mixture water, GBFS have the advantage of early strength due to effect of activation. We investigated the compressive strength properties of GBFS concrete using wash water from recycled aggregate. According to the experimentation result, ICP-OES showed wash water from recycled coarse aggregate has a high alkali value of pH of 12. Also, compressive strength in early age using wash water can be improved as an activation.

• 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.

• Journal of the Korean Geotechnical Society
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• v.26 no.3
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• pp.5-12
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• 2010

In this study, in order to clarify the effect of the direction of cyclic shear on the post-earthquake settlement the multi-directional shear tests were carried out for Toyoura Japan standard sand, Genkai natural sand, Kaolinite and the Granulated Blast Furnace Slag (GBFS). The diameter and the height of the specimen are 75 mm and 20 mm, respectively. In a series of tests, the number of strain cycles was adjusted as n=5, 20, 30, 100, 200 and the shear strain amplitudes were varied from 0.1% to 1.0%. The relative densities of each samples were also adjusted as Dr=50, 60 and 70%. From the test results for Toyoura sand and GBFS, it is clarified that the post-earthquake settlement is relatively large at the small relative density and becomes large with the shear strain amplitude. When the influence of difference on the direction of cyclic shear decreases, the post-earthquake settlement strain for Toyoura sand is converged to a constant value, but the GBFS increases with the number of strain cycles. In addition, the post-earthquake settlement is in the order of Kaolinite > Toyoura sand > Genkai sand > GBFS.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1091-1094
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• 2000

An experimental study is carried out to estimate the way of applying the granulated blast furnace slag[GBFS] to the lean concrete subbase of concrete pavement. According to the test results, this application seems promising. For this application, mixing percent of GBFS ranging from 30 to 45 is recommendable at this stage. Expected benefits using GGBFS in the field of concrete pavement include reduced shrinkage crack, reduced pavement thickness, and extended service life.

• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.441-448
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• 2020

In this study, the engineering characteristics of CLSM mixed with GBFS and GF were identified to review the applicability as a replacement material and further evaluate the recharge and field applicability as a joint filler material. This study has resulted in the following findings. First, Using more than 30% of GBFS to replace FA enabled bleeding control through improved fluidity. Moreover, it has been confirmed that effective strength and proper quality can be achieved when it was applied as a refiller and joint filler material with higher early strength than the base material. Second, When using more than 30% of FNS to replace sand, it was found that adding 0.3~0.35 of the AE agent is effective for bleeding control through improved fluidity. Third, When using more than 30% of both GBFS and FNS in combination, it was found that adding 0.3~0.35 of the AE agent is effective for bleeding control through improved fluidity. Also, it was confirmed that proper mixing of 15~60% of GF secured the effective strength and desired quality as a refiller and joint filler material. Fourth, The relationship between the superficial level and internal micro pores of CLSM from the curing process needs to be discussed and reviewed in more detail through further research studies.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1212-1217
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• 2008

In this study, in order to clarify the effect of the direction of cyclic shear on the post-earthquake settlement the multi-directional shear tests were carried out for Toyoura Japan standard sand, Genkai natural sand and the Granulated Blast Furnace Slag (GBFS). In a series of tests, number of strain cycles was changed as n=5-200 and the shear strain amplitude varied from 0.1% to 1.0%. The relative density was also changed as Dr=50, 60 and 70%. From the test results for Toyoura sand and GBFS, it is clarified that the post cyclic settlement is relatively large at the small relative density and becomes large with the shear strain amplitude. When the influence of the direction of cyclic shear is decreases, the post cyclic settlement strain for Toyoura sand is converged to a constant value, but the GBFS is increased with the number of strain cycles.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.72-73
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• 2021

In this study, the engineering characteristics of CLSM mixed with GBFS and GF were identified to review the applicability as a replacement material and further evaluate the recharge and field applicability as a joint filler material. First, Using more than 30% of GBFS to replace FA enabled bleeding control through improved fluidity. Second, When using more than 30% of FNS to replace sand, it was found that adding 0.25~0.35 of the AE agent is effective for bleeding control through improved fluidity. Third, When using more than 30% of both GBFS and FNS in combination, it was found that adding 0.3~0.35 of the AE agent is effective for bleeding control through improved fluidity. Also, it was confirmed that proper mixing of 15~60% of GF secured the effective strength and desired quality as a refiller and joint filler material.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.267-274
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• 2006

Greenhouse gas reduction will be highlighted as the most pending question in the cement industry in future because the production of Portland cement not only consumes limestone, clay, coal, and electricity, but also release waste gases such as $CO_2,\;SO_3$, and NOX, which can contribute to the greenhouse effect and acid rain. To meet the increase of cement demand and simultaneously comply with the Kyoto Protocol, cement that gives less $CO_2$ discharge should be urgently developed. This study aims to manufacture non-sintering cement(NSC) by adding phosphogypsum(PG) and waste lime(WL) to granulated blast furnace slag(GBFS) as sulfate and alkali activators. This study also Investigates the hydration reaction of NSC through analysis of scanning electron microscopy(SEM), X-ray diffraction(XRD), differential thermal analysis(DTA), and pH. Results obtained from analysis of the hydrate have shown that the glassy films of GBFS are destroyed by the activation of alkali and sulfate, ions eluted from the inside of GBFS react with PG and produce ettringite, and consequently the remaining component in GBFS slowly produced C-5-H(I) gel. Here, PG is considered not only to play the role of simple activator, but also to work as a binder reacting with GBFS.