• Journal of Ocean Engineering and Technology
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• v.12 no.1
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• pp.153-161
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• 1998

This paper is to investigate the Fluidity of Antiwashout Underwater Concrete containing Fly Ash. The results of study are concluded as follows: the increase in Slump Flow value did not happen in the plain concrete which was replaced cement by Fly Ash; however, the maximum value could reach in the replacement of 30% of Fly Ash by weight of cement in the Fly Ash replaced concrete. On the condition of Fly Ash-Antiwashout Underwater Concrete in expecting 50 cm of the Slump Flow, it was necessary that the usage amount of Superplasticizer be around 1% of unit Binder, and 1.5% in 60 cm of the Slump Flow, respoectively.

• Journal of environmental and Sanitary engineering
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• v.18 no.2
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• pp.34-41
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• 2003

The purpose of this study is to examine the effect of stabilization disposal and recycling on incinerated paper mill sludge ash as cement additives. It was investigated chemical(pH, ICP, TGA XRD) and physical(PDA, SEM) characteristics of the incineration ash. And the pozzolanic characteristics of incineration ash was applied to cement as additive to increase the compressive strength. The results were that the pH characteristic of incineration ash was strong alkalinity, the content of silica and alumina as a pozzolanic material was 50.97%, and the average particle size was $5.03{\mu}m$ respectively. When the ash contents as cement additive were varied in 0~15%(wt) of cement weight to explore the effect of the compressive strength on the solidified cement mortar, the proper amount of the incineration ash substituted was about 5~l0%(wt). Therefore we found that using the incineration ash as cement additive obtains the recycling of waste material, the stabilization disposal, the reduction of waste disposal expense, and the protection of environmental problem, too.

• Journal of Ocean Engineering and Technology
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• v.15 no.3
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• pp.128-133
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• 2001

It is generally known that the concrete structure subjected to severe environment is much affected by the corrosion of reinforcement, the freezing and thawing action of concrete structure. The main objective of this study is to investigate the freezing and thawing resistance of concrete including fly ash. The effect of the air content in concrete using fly ash is investigated. The experimental study is conducted for 10 mix-ratio cases of concrete of which variables are content of fly ash, concrete compressive strength and containment of air-entrained admixtures. Test results show that the freezing and thawing resistance improves as the amounts of fly ash increase, and concrete with air-entrained admixtures has good freezing and thawing resistance. The concrete with fly ash is to be included air-entrained admixture according to content of fly ash in order to increase the freezing and thawing resistance.

• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.66-71
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• 2000

The main objectives of this study are to carried out in order to evaluate strength development of Fly Ash concrete containing various amounts of Fly Ash such as 0%, 10%, 20% and 30%. The experimental variables included in this test program consist of content of Fly Ash, concrete strength and chemical activation. As Fly Ash increases, air content, strength development of concrete and slump loss of normal strength concrete were gradually decreased. The inclusion of Na$_2$SO$_4$increased the short-term strength of concrete that contains Fly Ash. In addition, the strength development of concrete that contains Fly Ash and Na$_2$SO$_4$were improved.

• Journal of Ocean Engineering and Technology
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• v.14 no.1
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• pp.74-79
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• 2000

The purpose of this paper is to recycle coal ash as structural backfill materials from electric power plants. Two million tons of coal ash are produced annually. The laboratory test was executed for the basic compatibility as substitution for structural backfill materials and the optimal mixture ratio(fly ash : bottom ash) was decided. In addition the model test was performed using medium scale earth pressure model with small size earth pressure cells model box data logger and some other apparatuses. Mixed coal ash and excellent backfill materials(coheisonless soil SW) were compared in the view of lateral earth pressure variation depending on wall displacement. The reduction of earth pressure when coal ash was used as a bockfill material was monitored comparing to that of cohesionless soil. the cost and environmental pollutants by treating coal ash can be reduced through developing the recycling technology.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.334-339
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• 1995

To investigate the utilization of fly ash in agriculture, sorghum [Sorghum bicolor(L.) Moench] was used as the test crop. Soil was treated in pot experiments with anthracite and bituminous fly ash at 5 levels of 0, 6, 12, 18, and 24%, respectively. Growth status in terms of plant height and the number of nodes was improved in the order of bituminous treatment > anthracite treatment > control. The increment of fly ash had a positive effects on plant growth in both anthracite and bituminous treatment. The ratio of the senescent leaves to the all leaves during the maturing period was higher in fly ash treatments than in the control. As increasing the fly ash treatment, the ratio of senescent leaves was increased. Total yield was higher in the order of bituminous treatment > anthracite treatment > control. Grain yield also was higher in fly ash treatment than in the control. Bituminous fly ash treatments were more favourable in grain yield than anthracite. The increment of up to 12% fly ash to soil increased grain yield in both anthracite and bituminous. Application of bituminous fly ash could be recommended due to the fact that high pH of soil is favorable for growth of sorghum.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.5-12
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• 1998

Pot experiment was conducted to investigate the effects of fly ash on growth responses and on accumulation of the heavy metals in soil. Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 0.4, 0.8, and 1.2 kg/pot(20L). Tobacco growth was better by application of fly ash than that by the control. However, the early stage of growth by application of bituminous coal, 1.2 kg/pot, was decreased due to the boron toxicity occurred by fly ash. Generally, tobacco yield was significantly increased with applying fly ash, showing the highest yield at 1.2 kg/pot for anthracite and at 0.8 kg/pot for bituminous coal. The content of total nitrogen in leaves was higher with fly ash than that of the control, while the content of calcium in leaves was low, Contents of heavy metal and the other minerals were not significantly different between the control and the treatment of fly ash. Soil pH after experiment was linearly increased with application level of fly ash, indicating that the application of bituminous coal was more effective than that of anthracite. Contents of available phosphate, exchangeable $Ca^{2+}$+ and $Mg^{2+}$ in soil were increased by application of fly ash, especially with bituminous coal. Contents of Cu, Cr, and Ni were increased with application level of bituminous coati even if the contents were still lower than critical levels for farming land. The other heavy metals were similar between the control and the application of fly ash.

• Geotechnical Engineering
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• v.11 no.2
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• pp.99-106
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• 1995

Although lots of experimental studies of coal ash have been performed to study the utilization as construction materials, the environmental characteristics of coal ash are still qestionable. In this study, fly ash is examined to be classified according to Korean Environmental Standard and analized whether the batch test results are within the toler trance limit when utilized or treated as reclamation and earth work materials. The batch tests was performed to examine pH and contaminant contents. Consequently, fly ash is classified as non hazardous industrial waste. The pH value shows a strong alkalinity than the tolerance limit, but it is implied that fly ash can be used to neutralize the acid ground. All other items except pH satisfy the tolerance limit, In addition, a small quantity of additives(cement) which used to improve the poor geotechnical properties of coal ash, could decrease the pH value into the tolerance limit as well as improve strengtIL durability and permeability. It is concluded that when coal ash is used properly, there is no enviormental harmfulness as construction materials.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1032-1039
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• 2010

Based on the proven feasibility of bottom ash and tire shred-soil mixtures as lightweight fill materials, tire shred-bottom ash mixtures were suggested as a new lightweight fill material to replace the conventional construction material with bottom ash. Therefore, we carried out the laboratory test, field compaction test and performance test of large scale embankment in order to evaluate their suitability for the use of lightweight fill materials in the before studies. We could verified that the ash, tire-shred and the mixture are able to be the useful materials as light fill materials. In this study, we built real scale embankment with RBA(Reclamated Bottom Ash), TRBA(Tire shred-Reclamated Bottom Ash mixture), WS(Weathered Soil), BA(Bottom Ash screened by 5mm sieve) for monitoring the behavior such as settlement, lateral displacement and water content change. Furthermore, we are examining the ground water quality in the surrounding area of the test embankment.

• Journal of the Korean Ceramic Society
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• v.49 no.2
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• pp.185-190
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• 2012

The purpose of this study was to examine a possibility that fly ash could be used as raw material for carbonation by conducting the experiment on magnetic separation and hydration of fly ash that contained a large amount of CaO composite. Wet magnetic separation experiment was performed to remove the component of magnetic substance that contained fly ash, which aimed at increasing the content of CaO in the non-magnetic domain. The selected fly ash was used for hydration experiment before the TG-DTA, XRF and XRD analyses were made to confirm the Ca component that could be carbonated. Then, the fly ash was turned to a hydrate that was favorable to dissociation of $Ca^{2+}$ ion. As a result, the magnetic separation enabled detecting the content of CaO component by up to 61 wt% in the non-magnetic domain. Since the hydrate was confirmed, it is believed that the fly ash can be used as raw material for carbonation.