• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.50-56
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• 2019

This study aims to make artificial stone by recycling blast furnace slag powder, red mud and recycled aggregate, which are known as industrial waste. Recycled aggregate is a typical construction waste, and various recycled products such as concrete block are being sold. In this study, we tried to make artificial stone mixed with waste such as recycled aggregate, and experimented with the use of artificial stone and further study. As the red mud replacement ratio increased, the absorption ratio, fluidity and air content of the matrix were measured to be decreased, and the strength and density were found to increase. The fluidity and absorption ratio decreased with increasing the replacement ratio of recycled aggregate, and the air quantity, rate of aggregate on the surface, density and intensity increased to a certain level. Therefore, this study intends to make artificial stone using recycled resources and conducted basic experiments for further study.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.339-342
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• 2000

Recently, the importance of the conutermeasures for waste materials has pointed out. Waste glass is also one to waste materials used for the recycling in construction sites. The crushed waste glass has been used to make a glass polymer composite that can be applied for sewer, storm drain pipe and interlocking block, etc. In this study, the crushed waste glass is explored with the possibility of recycling it, as a substitute for fine aggregates. The prepose of this investigation is to improve the strengths and acid resistance of the UP mortars using crushed waste glass. The UP mortars are prepare with blast furnace slag fly ash filler. the UP-fine aggregate ratios the crushed waste glass replacements for fine aggregate are tested strengths before and after immersion(H (아래첨자2)SO(아래첨자4) 10%), weight change and acid resistance are also tested. From the test results, the relative strength or UP mortars using fly ash as filler are found to be somewhat superior to that of the UP mortars using blast furnace as filler, And a UP mortar with fly ash as a filler, a UP-fine aggregate ratio of 15% and a waste glass replacement if 50% for fine aggregate is recommended as optimal mix proportion of UP mortar using crushed waste glass. Accordingly, it is enough to assure the use of the crushed waare glass as an aggregate for the production of UP mortar.

• Advances in concrete construction
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• v.13 no.3
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• pp.233-242
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• 2022

An attempt is made to develop an eco-friendly concrete with ground granulated blast furnace slag (GGBS) and pond ash as partial replacement materials for cement and fine aggregate, respectively without compromising the strength and durability. Sixteen concrete mixes were developed by replacing cement and fine aggregate by GGBS and pond ash, respectively in stages of 10%. The maximum replacement levels of cement and fine aggregates were 50% and 30% respectively. Experimental results revealed that the optimum percentage of GGBS and pond ash replacement levels were 30% and 20% respectively. The optimized mix was used further to study the flexural behavior and durability properties. Reinforced Concrete (RC) beams were cast and tested under a four-point bending configuration. Also, the specimens prepared from the optimized mix were subjected to alternate wet and dry cycles of acid (3.5% HCl and H₂SO₄) and sulphate (10% MgSO₄) solutions. Results show that the optimized concrete mix with GGBS and pond ash had a negligible weight loss and strength reduction.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.147-153
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• 2010

The recycling of demolished concrete as an alternative source of coarse aggregates for the production of new concrete can help to solve the growing waste disposal crisis and the problem of the depletion of natural aggregates. The purpose of this study is to investigate the chloride migration of recycled aggregate concrete containing pozzolanic materials by the chloride migration coefficient. The specimens were made with recycled coarse aggregate at various replacement ratios (10, 30, 50%) and metakaolin, blast furnace slag, and fly ash is replaced for recycled concrete with a mixing ratio of 20%. The major results are as follows. 1) The compressive strength of recycled aggregate concrete containing pozzolanic materials increases as the curing age and chloride diffusivity decreases. 2) When the replacement ratio of recycled coarse aggregate is 30%, the chloride migration coefficient of recycled concrete containing blast furnace slag or metakaolin that shows a value similar to or lower than that of plain concrete at all ages.

• Geotechnical Engineering
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• v.12 no.3
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• pp.17-34
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• 1996

The objective of this paper is to evaluate the asphalt mixture performance with pyrolyzed carbon black(CBP) and air -cooled iron blast furnace slag. Marshall mix design was performed to determine the optimum binder content, The optimum binder content ranged from 6.3 percent to 7.75 percent. Dynamic creep testing was carried out using mixtures at the optimum binder content. Based on the test results, the use of pyrolyzed carbon black and slag in the asphalt pavement showed a positive result, such as the increase of Marshall stability, the decrease of the strain rate and the decrease in the mix stiffness rate at high temperature(5$0^{\circ}C$) and 137.9 kPa confinement. Within the limits of this research. it was concluded that pyrolyzed carbon black as an additive and slag as a coarse aggregate could be used to produce an asphalt paving mixture that has good stability, stiffness, and rutting resistance.

• Computers and Concrete
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• v.23 no.6
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• pp.421-431
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• 2019

The alarming rate of depletion of natural stone based coarse aggregates is a cause of great concern. The coarse aggregates occupy nearly 60-70% by volume of concrete being produced. Research efforts are on to look for alternatives to stone based coarse aggregates from sustainability point of view. Response surface methodology (RSM) is adopted to study and address the effect of ferrochrome slag (FCS) replacement to coarse aggregate replacement in the ordinary Portland cement (OPC) based concretes. RSM involves three different factors (ground granulated blast furnace slag (GGBS) as binder, flyash (FA) as binder, and FCS as coarse aggregate), with three different levels (GGBS (0, 15, and 30%), FA (0, 15, and 30%) and FCS (0, 50, and 100%)). Experiments were carried out to measure the responses like, workability, density, and compressive strength of FCS based concretes. In order to optimize FCS replacement in the OPC based concretes, three different traditional optimization techniques were used (grey relational analysis (GRA), technique for order of preference by similarity (TOPSIS), and desirability function approach (DFA)). Traditional optimization techniques were accompanied with principal component analysis (PCA) to calculate the weightage of responses measured to arrive at the final ranking of replacement levels of GGBS, FA, and FCS in OPC based concretes. Hybrid combination of PCA-TOPSIS technique is found to be significant when compared to other techniques used. 30% GGBS and 50% FCS replacement in OPC based concrete was arrived at, to be optimal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5C
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• pp.171-185
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• 2011

Ready-mixed shotcrete that mixed with high quality aggregate and can improve construction quality is produced in a dry mortar plant and transported to construction sites. Because of using aggregate that produced in a special plant, Ready-mixed shotcrete has many advantages : good grain-size distribution, minimum stone powder, high quality and standardization material, etc. In this basic study different from the existing study that limited to additive and accelerator, the improvement of aggregate quality was tried to upgrade the shotcrete performance. The investigation about the construction conditions of shotcrete was performed and the result of an opinion poll was analyzed for a good grasp of the problems in domestic shotcrete quality. Pilot Plant Test was also performed to minimize the material segregation in plant manufacturing process. In additions, the field test was performed to find the optimum contents of synthetic fiber, appearing the same flexible toughness with that of steel fiber, and to find the optimum replacement ratio of blast furnace slag.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.37-38
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• 2013

The fine powder obtained from the manufacturing process of recycled coarse aggregate contains unhydareted cement particles on their surface. It is believed that the alkalinity of the powder (11.0-12.5) is enough to active the slag-based composites. In this paper, the obtained powder was sieved and divided into two sizes, i.e., 0.08 mm and 0.3 mm, and added to the slag-based mortar. Results showed that the fine powder had an effect on the slump and the compressive strength of slag-based composites. With the different pH values of the powder, it could be seen that the distance between the two level powders. And found the peak 28 days compressive strength as the replacement ratio of the recycled aggregate powder changed. The findings from this study provide an indication that with achieved compressive strength, the fine powder can be used in a light weight concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.113-119
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• 2019

Many researches on alternative materials as construction materials is continuing by recycling industrial byproducts due to shortage of sitereclamation and natural aggregates. In this paper, engineering properties in early-aged OPC (Ordinary Portland Cement) and GGBFS (Ground Granulated Blast Furnace Slag) concrete are evaluated with EOS aggregate replacement. The related experiments were carried out with 0.6 of water to binder ratio, three levels of EOS replacement ratios (0%, 30% and 50%) for fine aggregate, and two levels of cement replacement with GGBFS (0% and 40%). Several tests such as slump air content, and unit mass measurement are performed for fresh concrete, and compressive strength and diffusion coefficient referred to NT BUILD 492 method are measured for hardened concrete. Through the tests, it was evaluated that the compressive strength in concrete with EOS aggregate increased to 3 days and 7 days but slightly decreased at the age of 28 days. In the accelerated chloride penetration test, GGBFS concrete showed reduced diffusion coefficients by 60 - 67% compared with OPC concrete. The lowest chloride diffusion coefficient was evaluated in the 50% replacement with EOS aggregate, which showed an applicability of EOS aggregate to concrete production.

• Magazine of the Korea Concrete Institute
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• v.9 no.1
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• pp.115-121
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• 1997

This study deals with the suppressing characteristics of alkali-silica reaction by ground granulated blast-furnace slag(GGBS) in NaCl solution. NaCl contents used in the experiment ranges over 0%, 2.8% and 20%. Reactive aggregate used is Japanese andesite. Also, three GGBSs of about 4.000. 6, 000 and $8, 000cm^2/g$ were used in the experiment. The replacement proportions of portland cement by GGBSs were 40%. 60%, 70% and 80%. respectively. The specimens with GGBS were severely contracted according to the increasing replacement ratio in NaCl solution. The contraction rate increases according to the increasing in NaCl content. Also. it does with increasing the blaine fineness of GGRS. It is concluded that the suppression of alkali-silica reaction by GGBS in NaCl solution is complished by contraction of GGBS due to chloride ion induced chemical shrinkage.