• Geotechnical Engineering
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• v.11 no.3
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• pp.37-42
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• 1995

The laboratory hydraulic conducti vita tests with rigid wall permeameter were performed to study the effects of waste leachate on the permeability of a marine clay. The marine clay and waste leachate for this study were sampled from Kimpo Wastefills, and the hydraulic gradients applied to the clay specimens aTe relatively high from 37.5 to 225. The test results show that the permeability of a marine clay is increased with increasing the concentration of leachate and with decreasing the hydraulic gradient. And also both the liquid limit and the plasticity index of the marine clay miRed with waste leachate decrease with increasing the concentration of leachate.

• Journal of the Korea Institute of Building Construction
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• v.7 no.2 s.24
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• pp.93-98
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• 2007

Waste of Plastic that is waste tile and waste interlocking block result, waste tile and waste interlocking block that execute an experiment to foretell practical use possibility availability as recycled aggregate for concrete giving change in the principal parts rate for coarse aggregate recycled aggregate appeared in the world by available thing to coarse aggregate to rate 10% but necessity that present amount used establishing material application standard that is crushed than uniform application standard to receive entropy of re-fresh concrete quality is judged to be.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.219-226
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• 2020

Over the last decades, great efforts have been devoted to reuse industrial wastes and by-products from various industries as supplementary cementitious materials in order to reduce carbon dioxide(CO₂) emission by reducing the use of Portland cement in construction. Oyster shell waste, originating from the fishery industry, is available in huge quantities in certain areas, and is generally discarded or landfilled. In this study, we aimed to reuse oyster shell as an alternative to limestone in limestone calcined clay cement(LC³). The oyster shell calcined clay cement(OC³) paste were produced and were characterized via X-ray diffraction, isothermal calorimetry, compressive strength tests, and thermogravimetry. The results revealed that OC³ pastes exhibited similar strength development and reactivities by pozzolanic reaction with LC³, which implies that oyster shell could be used as a substitute for limestone in LC³.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.575-585
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• 2013

This research was performed to evaluate the recycling feasibility as a construction material of dredged harbor soil mixed with clay and glass frit. Concentration of heavy metals of the dredged soil from D harbor was severly high, showing Zn of 526.0~13,150.1 mg/kg. The dredged soil was maily composed of 48.30 wt% $SiO_2$, 16.60 wt% $Al_2O_3$, 10.10 wt% CaO, 7.75 wt% $Fe_2O_3$. The clay and the glass frit contained 70.82 wt% $SiO_2$ and $Al_2O_3$ 18.78 wt%, and 71.75 wt% $SiO_2$, 13.99 wt% CaO, 8.51 wt% $Na_2O$, respectively. After adding 10~40 wt% to the clay and sintering them at $1,000^{\circ}C$ or $1,100^{\circ}C$, the compressive strength of the sintered specimens showed $132.6{\sim}178.5kgf/cm^2$ or $581.2{\sim}793.7kgf/cm^2$, respectively. In case of SC46 with the addition 40 wt% of the dredged soil to the clay, the compressive strength ($793.7kgf/cm^2$) of specimen sintered at $1,100^{\circ}C$ was over 5 times higher than that at $1,000^{\circ}C$. The specimen mixed with 40 wt% of dredged soil, 60 wt% of clay and 1 wt% of glass frit satisfied the 1st grade standard for clay brick by KS L 4201. The results of all specimens by Korean Standard Leaching Test also satisfied the standard criteria.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.209-217
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• 2011

In recent days, while taller and more massive structures such as huge bridges and super skyscrapers have been welcomed, the structural stabilization in design and construction have been gradually limited due to the major weakness of current concrete which is relatively heavier when compared with its strength. To improve the weakness of the current concrete, The lightweight concrete with light weight and high strength should be used; however, not many researchers in Korea have studied on the lightweight concrete. Generally, artificial lightweight aggregate produced through high-temperature-plasticization has a possibility of its body-expansion with many bubbles. Therefore, depending on the size of aggregate, the effects of bubbles on the specific weight and strength of the lightweight concrete should be studied. In this study, considering grain-size, the mix design of the artificial lightweight aggregate produced through the high-temperature-plasticization and the body-expansion of waste and clay from the fire power plant in Korea was conducted. The experiment to analyze the variation in specific weight and strength of the lightweight concrete was followed. From these experiments, the optimized grain-size ratio of the artificial lightweight aggregate for the enhancement of high-strength from the lightweight concrete was revealed.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.285-297
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• 2021

Globally, nuclear-decommissioning facilities have been increased in number, and thereby hundreds of thousands of wastes, such as concrete, soil, and metal, have been generated. For this reason, there have been numerous efforts and researches on the development of technology for volume reduction and recycling of solid radioactive wastes, and this study reviewed and examined thoroughly such previous studies. The waste concrete powder is rehydrated by other processes such as grinding and sintering, and the processes rendered aluminate (C3A), C4AF, C3S, and ��-C2S, which are the significant compounds controlling the hydration reaction of concrete and the compressive strength of the solidified matrix. The review of the previous studies confirmed that waste concretes could be used as recycling cement, but there remain problems with the decreasing strength of solidified matrix due to mingling with aggregates. There have been further efforts to improve the performance of recycling concrete via mixing with reactive agents using industrial by-products, such as blast furnace slag and fly ash. As a result, the compressive strength of the solidified matrix was proved to be enhanced. On the contrary, there have been few kinds of researches on manufacturing recycled concretes using soil wastes. Illite and zeolite in soil waste show the high adsorption capacity on radioactive nuclides, and they can be recycled as solidification agents. If the soil wastes are recycled as much as possible, the volume of wastes generated from the decommissioning of nuclear power plants (NPPs) is not only significantly reduced, but collateral benefits also are received because radioactive wastes are safely disposed of by solidification agents made from such soil wastes. Thus, it is required to study the production of non-sintered cement using clay minerals in soil wastes. This paper reviewed related domestic and foreign researches to consider the sustainable recycling of concrete waste from NPPs as recycling cement and utilizing clay minerals in soil waste to produce unsintered cement.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.210-215
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• 2004

Porous ceramics for water-permeable paving brick was prepared by the sintering of mixed materials comprising of sewage sludge ash, waste porcelain fragment, waste glaze and low-grade clay at 1,000$^{\circ}C$ for 2 h, and the physical $.$mechanical properties, the permeability and the freeze-thaw resistance of specimens with preparation parameters were investigated. The physical mechanical properties were increased in specimens while porosity and permeability were decreased with increasing sewage sludge ash content and sintering temperature on the properties of specimens showed the opposite results. The bulk density, porosity, compressive strength and permeability (passed charge) of 30A60F specimens with 30 wt% of sewage sludge ash content, waste porcelain fragment size with 1∼2 mm and sintered at 1,000$^{\circ}C$ for 2 h were 2.17, 46.2%, 221 kgf/$\textrm{cm}^2$ and 3,150 coulombs, respectively. The permeability was increased with increasing waste porcelain fragment size, however compressive strength was decreased. The freeze-thaw resistance of 30A60F specimen with 1∼2 mm of fragment size was superior to that of the other specimens. The 30A60F specimens can be used for the water-permeable paving brick with the high permeability and adequate strength. The heavy metals included in the all specimens showed lower than the standard level.

• Journal of Aquaculture
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• v.9 no.3
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• pp.239-245
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• 1996

As one of the red tide control method, montmorillonite was used to eliminate the causative organisms in Korea and Japan. We assayed the loess to replace the montmorillonite because it distribute in large quantity and nearby the red tide occurrence in South Coast of Korea. By using the mixture of loess and coal ashes, we examined the decreasing level of nutrients such as ammonia and phosphate, the elimination of causative organisms as a chlorophyll a content, and the harmful effect on aquaculture orgarnisms in cage culture farms. Half of the ammonium and phosphate was adsorbed by the loess particles, but only $25\%$ of ammonium was adsorbed by the coal ashes particles. In water column test, the particles of loess and coal ashes were settled down by $80\%$ in 20 minutes, the red tide organisms was eliminated by $80\%$ after 2 hours in 1,000 ppm of loess suspension, but the organisms were eliminated only $30\%$ by the same concentration of coal ashes. The harmful test of fishes and invertbrates, we observed any other negative effects of test animals than a tint deceleration in yellowtail.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.221-228
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• 2004

Basic properties of artificial lightweight aggregate by using waste dusts and strength properties of LWA concrete were studied. Bulk specific gravity and water absorption of artificial lightweight aggregates varied from 1.4 to 1.7 and 13 to 16%, respectively. Crushing ratio of artificial lightweight aggregate was above 10% higher than that of crushed stone or gravel. As a result of TCLP leaching test, the leaching amount of tested heavy metal element was below the leaching standard of hazardous material. Slump, compressive strength and stress-strain properties of LWA concrete made of artificial lightweight aggregate were tested. Concrete samples derived from LWA substitution ratio of 30 vol% and W/C ratio of 45 wt% showed the best properties overall. Thermal insulation and sound insulation characteristics of light weight concrete panel with the optimum concrete proportion were tested. Average overall heat transmission of 3.293W/㎡$^{\circ}C$ was observed. It was higher by about 15% than those of normal concrete made by crushed stone. Sound transmission loss of 50.9 ㏈ in frequency of 500 ㎐ was observed. It was higher by about 13% than standard transmission loss.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.5
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• pp.211-216
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• 2008

The artificial lightweight aggregate (ALA) was manufactured in a rotary kiln at $1125^{\circ}C$ using green body formed by pelletizing the batch powder composing of coal bottom ash (CBA) produced from power plant, clay and dredged soil (DS). The TCLP (Toxicity characteristic leaching procedure) results showed that the dissolution concentration of heavy metal ions of ALA fabricated in this study was below the limitation defined by the enforcement regulations of wastes management law in Korea. The ALA containing 60$\sim$70 wt% CBA had a bulk density of 1.45$\sim$1.49 and a water absorption of 17.2$\sim$18.5 %. The impact values for oven-dry state and saturated-surface dry state of ALA were 27.4$\pm$1.3 and 23.4$\pm$2.6 % respectively. The 28-days compressive strength of concrete made with various ALA was $22.7\sim27.8 N/mm^2$. The slump of concrete with ALA containing CBA 60 and 70 wt% were 7.9 and 14.3 cm respectively. The unit weight of concrete made with any ALA fabricated in this study was satisfied with the standard specifications of lightweight concrete for the civil engineering and construction presented by Korea as below $1.84 ton/m^3$.