• Journal of the Korean GEO-environmental Society
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• v.19 no.6
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• pp.13-22
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• 2018

The southwestern part of Korean Peninsula, which length is about 13,000 km, is largely formed with soft cohesive soil ground and when it is developed, the low bearing capacity and excessive settlement of soft ground give many problems. In particular, a lot of clayey soil is deserted due to high moisture content and weakness, and areas formed with soft ground. In this study it was performed unconfined compression test, CBR tests, laboratory frost heaving test, and wheel tracking test in order to determine the optimum mixture ratio of paper sludge ash added chemical stabilizer with soft soil for consideration of its frost heaving and strength characteristics. As a results of the above experiments, when the soft soil is mixed with 6% of chemical stabilizer to improve the soft soil for utilizing as a subgrade soil material. It is satisfied the quality standard of fill materials, and the results of this research are expected to be used as an appropriate usage standard for utilization of on-site soil generated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.59-66
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• 1988

At the present time, annually about 2 million tons of coal ashes are generated from thermal power plants in Korea, however, they are dumped into ash ponds mixed with sea water very expensively. In this thesis, engineering characteristics of bituminous and anthracite ashes are studied to utilize them as construction materials. The coal ash is non-plactic material and its grain size falls in the range of silt, but it has better soil engineering characteristics than general soils of same grain size. For example, the permeability, shearing strength, CBR, and consolidation properties match to that of sandy soils, moreover, strengthening by hydration can be expected with the lapse of year because of CaO presence in the components. So, utilizing those coal ashes in a productive way as reclamation or banking materials is expected.

• Journal of Soil and Groundwater Environment
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• v.14 no.3
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• pp.47-56
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• 2009

This is a study about how the increase of strength is changed when ground improvement material is mixed with either coastal clay or sandy soil. The ground improvement material was made from mixing a certain proportion of the slag which is by-products generated by smelting the iron ore and the paper fly ash which is formed by bumping up the paper. The ground improvement material was added to coastal soil and sandy soil each. And then according to ratio of water contents, number of curing days and ratio of mixture, specimen for uniaxial compression test was made. The change of uniaxial compression strength and the generated substances was analyzed while the specimen is being cured for 28days. The result of analysis shows that the strength of coastal clay was increased about eleven times more than that of sandy soil. This means that ettringite reaction by ground improvement material becomes more distinctive in the coastal clay than in the sandy soil.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.85-91
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• 2011

This study aims at evaluating feasibility of Bottom ash-mixed Foam Cement Banking(BFCB) Method on the enhancement of soft soil, which is developed to reduce self-weight of banking by applying bottom ash and foam. to cement slurry. In order to measure the behavior of soil when BFCB layer was covered to soft ground, a testing equipment for mock-up test was fabricated and phased loads were applied up to measurement of yielding and ultimate strengths as well as movement of ground particles. In addition, these measured values such as settlement and heaving were compared with ones of surface-hardening method prevailing on soil improvement. As the result through mock-up test, BFCB showed lower values of ground deformation, while wider range of deformation was observed in compare to the other method. And settlement and heaving were measured lower, which implies the method developed is very effective to applicability of soft ground.

• Resources Recycling
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• v.5 no.1
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• pp.3-8
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• 1996

CZS(2Ca0 , SiO\ulcorner) phase of cement clinkcr was obtaincd by melting mixcd four indnstrial wasles of limestone sludge, waste Foundry sand, coal lly ash fiorn power plants and chernicas glasses. The effect ot mixing ratio of four rvastc mater~als ou the composnlg phascs in melled slag was investigated. Thc mixed wastes were meltcd to slag by heat under a constant basicity at 1370C. The shg consisted of p -CIS and C,AS(2CaO - A I P , . SiO,). The ratio of two phases was varied with mixing ~atioo f the waste materials. In order Lo increasc the amount ot j -C2S phase, the coal fly ash content should be reduced, while amount of the chemical glass be increased. The coal fly ash contcnt was the most imporlant factor in controlling phases of thc melted-slag.

• Advances in concrete construction
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• v.14 no.1
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• pp.1-13
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• 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 Korea Institute of Building Construction
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• v.21 no.6
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• pp.551-562
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• 2021

In this study, to suggest an efficient method of using coal gasification slag(CGS), a byproduct from integrated gasification combined cycle(IGCC), as a combined fine aggregate for concrete mixture, the diverse performances of concrete mixtures with combined fine aggregates of CGS, river sand, and crushed sand were evaluated. Additionally, using CGS, the reduction of the hydration heat and the strength developing performance were analyzed to provide a method for reducing the heat of hydration of mass concrete by using combined fine aggregate with CGS and replacing fly ash with cement. The results of the study can be summarized as follows: as a method of recycling CGS from IGCC as concrete fine aggregate, a combination of CGS with crushed sand offers advantages for the concrete mixture. Additionally, when the CGS combined aggregate is used with low-heat-mix designed concrete with fly ash, it has the synergistic effect of reducing the hydration heat of mass concrete compared to the low-heat-designed concrete mixture currently in wide use.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4C
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• pp.247-253
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• 2008

This paper investigates the mechanical characteristics of waste tire powder-added lightweight soil in which dredged soils, waste tire powder and bottom ash were reused. In this study, 5 groups of soil samples were prepared with varing contents of waste tire powder ranged from 0% to 100% at 25% intervals by the dredged soil weight. The mixed soil samples were subjected to unconfined compression and elastic wave tests to investigate their unconfined compressive strengths and dynamic properties. Test results showed that the unconfined compressive strength and unit weight decreased as the waste tire powder contents increased, but axial strain at failure increased. Also stress-strain relationship of waste tire powder-added lightweight soil showed a ductile behavior rather than a brittle behavior. The result of elastic wave tests indicated that the higher waste tire powder content, the lower elastic wave velocity and the lower shear modulus (G).

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.227-234
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• 2016

In this study, asphalt paving filler, which satisfies the KS standards, were prepared from industrial by-products, such as fly ash generated from thermal power plants, cogeneration ash generated from cogeneration plants, and desulfurized gypsum generated from the flue-gas desulfurization process. The properties of the prepared mixed filler and the existing limestone filler were compared through laboratory tests for preparing asphalt mixture using each filler. In addition, asphalt pavement field tests were conducted using the limestone filler and mixed filler. The dynamic stability, Marshall stability, tensile strength ratio, saturation, porosity, and flow value of the asphalt mixtures used in the field test were evaluated, as was done in the laboratory test. The laboratory and field construction test results revealed outstanding tensile strength ratio, Marshall stability and dynamic stability when using the prepared filler than for the existing limestone filler. Through optimization of the mixing design, the possibility of developing fillers, which the characteristics of the existing limestone filler, was confirmed.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.2
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• pp.69-78
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• 1995

When the food garbage of general hospital was dried by the rapid steam drying process, the water content was changed to 1.3% from 77.8~82.8%. In this experiment, weight reduction rate was 80%, and electricity consumption was 2.4Kwh. Dried compost from this rapid steam drying process was brown pellets, which was consist of 27.77% crude protein and 3.19% crude fiber. Even though these pellets were slightly short of crude fat and crude ash content, these were analysed as a possible supplementary feed for pig. On the condition of drying food garbage mixed with 5% pulverized chaff, the necessary drying time was shortened by 1 hour, weight reduction rate was 76%, and reduction rate of electricity consumption was 42%. But contents of crude fiber and crude ash were increased to about 2 times. In case of adding new food garbage continuously to the composted food garbage mixed with 3.4% pulverized chaff, weight reduction rate and contents of crude fiber and crude ash were decreased gradually, but contents of crude protein and crude fat were increased. In case of composting food garbage from buffet, both drying time and electricity consumption were reduced, and ingredients of compost were higher than that of assorted feed for pig in the market.