• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.257-262
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• 2000

The purpose of this study is grasping quality aggregate using Bottom Ash of Industrial Waste Incinerator, and is evaluating possibility of application as construction materials. Cement and Fly ash is used with binder of aggregates using bottom ash. It is tested for basic property and strength of artificial aggregates, and the results are compared with crushed stone and elution tests is done for environmental safety. In the results of tests, it is confirmed that basic property and strength are lowe than crushed stone but the aggregates have possibility of application as artificial lightweight aggregates. When it is manufactured with aggregates, it is sage environmentally because of protecting elution of harmful heavy metals.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.51-52
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• 2014

Recently, it is the global warming phenomenon because of the greenhouse gas exhaustion caused by and the environment problem is serious. And it is the situation where the problem of the exhaustion of resource because of the indiscriminate picking of the that is the raw material of the cement, limestone and natural aggregate are emphasized. In addition, thus the cement reduction amount of use and substitute material research is the urgent actual condition with the gas emission, which here it is generated in conducting compression molding in the building stone manufacturing process performance degradation phenomenon and fire resistance, and problem of the durability. Therefore, in this research, because of being the magnesia phosphate ceramics, the waste porcelain is applied and the anti-wearing character of the artificial stone according to it tries to be investigated.

• Computers and Concrete
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• v.27 no.4
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• pp.333-341
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• 2021

Steel slag, an industrial reject from the steel rolling process, has been identified as one of the suitable, environmentally friendly materials for concrete production. Given that the coarse aggregate portion represents about 70% of concrete constituents, other economic approaches have been found in the use of alternative materials such as steel slag in concrete. Unfortunately, a standard framework for its application is still lacking. Therefore, this study proposed functional model equations for the determination of strength properties (compression and splitting tensile) of steel slag aggregate concrete (SSAC), using gene expression programming (GEP). The study, in the experimental phase, utilized steel slag as a partial replacement of crushed rock, in steps 20%, 40%, 60%, 80%, and 100%, respectively. The predictor variables included in the analysis were cement, sand, granite, steel slag, water/cement ratio, and curing regime (age). For the model development, 60-75% of the dataset was used as the training set, while the remaining data was used for testing the model. Empirical results illustrate that steel aggregate could be used up to 100% replacement of conventional aggregate, while also yielding comparable results as the latter. The GEP-based functional relations were tested statistically. The minimum absolute percentage error (MAPE), and root mean square error (RMSE) for compressive strength are 6.9 and 1.4, and 12.52 and 0.91 for the train and test datasets, respectively. With the consistency of both the training and testing datasets, the model has shown a strong capacity to predict the strength properties of SSAC. The results showed that the proposed model equations are reliably suitable for estimating SSAC strength properties. The GEP-based formula is relatively simple and useful for pre-design applications.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.267-274
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• 2018

Though the wet bottom ash has been used as a type of lightweight aggregate, dry bottom ash, new type bottom ash from coal combustion power plant, has scarcely researched. It is excellent lightweight aggregate in the view point of construction material. This study is performed to check the applicability of dry bottom ash as a fine aggregate in lightweight aggregate concrete, by analyzing various properties of fresh and hardened concrete. We get results that the slump of concrete is within the target range at less than 75% replacement rate of dry bottom ash, the air content is not affected by the replacement rate of dry bottom ash, the bleeding capacity is less than $0.025cm^3/cm^2$ at 75% under of the replacement rate of dry bottom ash, and the compressive strength of concrete show 90% or more comparing the base mix while initial strength development is a little low. Oven dry unit weight of concrete is reduced by 8.9% when replaced 100% dry bottom ash, and dry shrinkage tends to decrease depending on increase of replacement rate of dry bottom ash. Modulus of elasticity of concrete shows no decease at 50% over of the replacement rate of dry bottom ash, while modulus of elasticity of concrete decreases when the replacement rate increases further. The dry bottom ash, when used as a fine aggregate in lightweight concrete, can be used effectively without any deterioration in quality.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.3
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• pp.125-130
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• 2008

If the properties of artificial lightweight aggregates produced by rotary kiln can be predicted by using a simulator equipped with a small electric furnace and a specially designed device for specimen movement, large amount of raw materials and plenty of test time can be saved to produce test products of lightweight aggregates. In this study a simulator for the accurate prediction of the artificial lightweight aggregates produced by rotary kiln was assembled by our own design and the properties of lightweight aggregates produced by both the simulator and rotary kiln were compared to speculate its usefulness. The average diameter of aggregates was 8 mm and atmosphere in the furnace was controlled by the amount of carbon powders. Specific gravity, absorption rate (%), black-core area in the cross-sectional view of both aggregates were measured and compared. Unlike oxydizing atmosphere, both specific gravity and absorption rate of the aggregates sintered at reducing atmosphere were increased with increasing carbon addition. It is concluded that the sintering atmosphere was the closest to that of the rotary kiln when the carbon addition was 0.7 g to make a reducing atmosphere in the furnace and the properties of both agreggates was also similar to each other.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.6
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• pp.277-282
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• 2007

The artificial lightweight aggregate (ALA) was manufactured using coal bottom ashes produced from a thermoelectric power plant with clay and, the sintering temperature and batch composition dependence upon physical properties of ALA were studied. The bottom ash (BA) had 13wt% coarse particle (>4.75mm) and showed very irregular shape so should be crushed to fine particles to be formed with clay by extrusion process. Also the bottom ash contained a many unburned carbon which generates the gas by oxidation and lighten a aggregate during a sintering process. Plastic index of green bodies decreased with increasing bottom ash content but the extrusion forming process was possible for the green body containing BA up to 40wt% whose plastic index and plastic limit were around 10 and 22 respectively. The ALA containing $30{\sim}40wt%$ BA sintered at $1100{\sim}1200^{\circ}C$ showed a volume specific density of $1.3{\sim}1.5$ and water absorption of $13{\sim}15%$ and could be appled for high-rise building and super-long bridge.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.2
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• pp.77-83
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• 2014

The purpose of this study was to figure out the impacts of iron oxide types and dosages to bloating when producing artificial lightweight aggregates by utilization of recycled resources such as bottom-ash, reject-ash and dredgedsoil. In order to figure out chemical characteristics of raw materials, XRD and XRF analyses were performed. 50 wt% of dredged-soil, 15 wt% of bottom-ash and 35wt.% of reject-ash were mixed, then the amount of iron oxide was varied at 5 to 30 wt% with intervals of 5 wt% with $Fe_2O_3$ and $Fe_3O_4$ respectively. As molded aggregates were sintered by rapid sintering in intervals of $40^{\circ}C$ from $1060^{\circ}C$ to $1180^{\circ}C$, specific gravity and water absorption were measured. As a result, the artificial lightweight aggregate with iron oxide of 10~15 vol% showed the lowest specific gravity, and it was identified that the more iron oxide vol% increases, the more specific gravity increases because of liquid phase sintering.

• Computers and Concrete
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• v.2 no.1
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• pp.79-96
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• 2005

The use of high-strength concrete (HSC) has significantly increased over the last decade, especially in offshore structures, long-span bridges, and tall buildings. The behavior of such concrete is noticeably different from that of normal-strength concrete (NSC) due to its different microstructure and mode of failure. In particular, the shear capacity of structural members made of HSC is a concern and must be carefully evaluated. The shear fracture surface in HSC members is usually trans-granular (propagates across coarse aggregates) and is therefore smoother than that in NSC members, which reduces the effect of shear transfer mechanisms through aggregate interlock across cracks, thus reducing the ultimate shear strength. Current code provisions for shear design are mainly based on experimental results obtained on NSC members having compressive strength of up to 50MPa. The validity of such methods to calculate the shear strength of HSC members is still questionable. In this study, a new approach based on artificial neural networks (ANNs) was used to predict the shear capacity of NSC and HSC beams without shear reinforcement. Shear capacities predicted by the ANN model were compared to those of five other methods commonly used in shear investigations: the ACI method, the CSA simplified method, Response 2000, Eurocode-2, and Zsutty's method. A sensitivity analysis was conducted to evaluate the ability of ANNs to capture the effect of main shear design parameters (concrete compressive strength, amount of longitudinal reinforcement, beam size, and shear span to depth ratio) on the shear capacity of reinforced NSC and HSC beams. It was found that the ANN model outperformed all other considered methods, providing more accurate results of shear capacity, and better capturing the effect of basic shear design parameters. Therefore, it offers an efficient alternative to evaluate the shear capacity of NSC and HSC members without stirrups.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.176-181
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• 2004

EAF (Electric Arc Furnace) dust is classified as special wastes containing heavy metal contaminants may cause to damage an environment such as underground water contamination if they were not treated properly. For reutilizing the EAF dust, the porous body was made from EAF dust/clay composition system, and analyzed pore characteristics. It was found that a light-aggregate body was made up two different microstructures. One was non-black and dense microstructure which located near surface, and the other was black and porous microstructure (black coring) which located inner part. For systematizing the relationship of the black-coring area and the bloating degree, we defined the Ic(core index) and Is(shell index). It was found that the optimal bloating conditions of artificial light-weight aggregate were more than 0.5 of Ic and 0.4 of Is.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.35-38
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• 2003

The purpose of this study is to investigate the manufacture of light weight concrete panel using the artificial light-weight aggregate as a part of the substitution of foamed styrene and polyurethane because of narrow allocable temperature Bone in use. The experimental parameter of this study is 40, 60 and 8$0^{\circ}C$ of curing temperature at 100% relative humidity and the type of admixture such as cement, 6mm glass fiber and St/BA emulsion. Testing item is compressive and flexural strength and strength of specimen cured at standard condition is compared to that of specimen cured at 40, 60 and 8$0^{\circ}C$ of curing temperature at 100% relative humidity. As a result or this, it was revealed that the maximum or strength is developed in 6$0^{\circ}C$ or cure temperature at 100% relative humidity in case of the most of the specimen. Specimens modified by St/BA emulsion show the highest development of strength dependent on the curing tmeperature. So, it seems to be effective that evaporation curing method shoud be considered to curing the specimen as the panel core.