• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.179-180
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• 2016

This study has a purpose of producing precast concrete for rapid construction of urban railway system. However, previous precast concrete has problem of its weight itself and there has been a keen interest in effect of carbon emission reduction and eco-friendly in our society. Therefore, in order to solve these two problems, we are about to produce precast concrete using lightweight aggregate and eco-lightweight concrete, with which much mineral had been replaced. As a result, we could confirm that it was possible to produce RMC B/P production satisfying the requirement performance of eco-lightweight concrete, which is replaced with a great amount of mineral for reduction of precast concrete's weight and environmental performance. Also, by confirming the possibility of producing precast concrete which lightweight concrete is used, if producing precast concrete by using eco-lightweight concrete, it would be effective to avoid destruction of environment and much useful to use multiple tower crane when constructing. Afterward, we will proceed our study by constructing precast concrete at which eco-lightweight concrete is used for continuous quality improvement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.187-188
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• 2016

The purpose of this study is to develop a method of evaluating eco-efficiency of concrete based on environmental load emission, manufacturing cost, and durability in the concrete production process. Eco-efficiency is an advanced concept used to evaluate eco-friendliness of concrete. This technique intends to produce environment-friendly and highly durable concrete while minimizing environmental load on the ecosystem and manufacturing cost based on the results of service life assessment on concrete. This technique can be utilized to efficiently evaluate sustainability of concrete and find methods to improve it. Furthermore, the vision of this study is to contribute to implementation of environment-friendly concrete and construction industry.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.533-544
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• 2015

Unlike the concrete structure built on land, that exposed to the marine environment is greatly degraded in durability due to the exposure to not only the physical action caused by sea wind, tide, and wave, but also the harsh conditions, including the chemical erosion and freeze-thaw which result from $SO_4{^{2-}}$, $Cl^-$ and $Mg^{2+}$ ions in seawater. In the process of the large scaled construction of submerged concrete structures, of course environmental hazardous substance, such as alkaline (pH) and heavy metals, may be leached. Thus, this issue needs to be adequately reviewed and studied. Therefore, this study attempted to develop a CSA (Calcium Sulfo Aluminate) activator using electric arc furnace reducing slags, as well as the eco-friendly concrete for artificial reefs using electric arc furnace oxidizing slag as aggregate for concrete. The strength properties of the eco-friendly concrete exposed to the marine environment were lower than those of the normal concrete by curing 28 days. This suggest that additional studies are needed to improve the early strength of the eco-friendly concrete. With respect to seawater resistance of the eco-friendly concrete, the average strength loss against 1 year of curing days reached 8-9%. the eco-friendly concrete using high volume of ground granulated blast furnace slags and high specific gravity of electronic arc furnace oxidizing slag demonstrated the sufficient usability as a freeze-thaw resistant material. With respect to heavy metal leaching properties of the eco-friendly concrete, heavy metal substances were immobilized by chemical bonding in the curing process through the hydration of concrete. Thus, heavy metal substances were neither identified at or below environmental hazard criteria nor detected, suggesting that the eco-friendly concrete is safe in terms of leaching of hazardous substances.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.817-826
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• 2011

Concrete using eco-cement has a problem with long-term strength development. However, currently, a long-term strength development mechanism is not confirmed, resulting in a lack of application of eco-cement in construction fields. In this study, the curing humidity influence on development in long-term strength of concrete using eco-cement and the relationship between strength and pore structure were examined. The results showed that wet cured eco-cement with a high water/cement ratio showed serious long-term strength reduction due to non-reduction of pore volume (pore size over 10 nm) in mortar caste with eco-cement. Also, the study results on improvement of long-term strength of eco-cement by partial replacement with ordinary portland cement and finely-ground fly ash showed that both of these alternatives improved long-term strength of concrete caste with eco-cement due to gradual refinement of their micro-structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.199-200
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• 2023

Eco-friendly concrete contains only 5% of cement yet achieves equal or greater strength compared to conventional concrete, reducing salt-attack impact and hydration heat by more than 30% and ensuring higher construction quality for underground structures. Furthermore, eco-friendly concrete can reduce up to 90% of carbon dioxide emissions compared to traditional concrete, enabling a reduction of approximately 6,000 tons of carbon emissions for 1,000 of apartment units construction. This is equivalent to planting around 42,000 trees

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1129-1134
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• 2001

In the point of the Eco-concrete(Environmentally Friendly Concrete), it is very important to reduce the pH of high porous concrete by the pH to be able to grow plants, because the pH of concrete is l1~13. But the method of measuring the pH of high porous concrete is not well-defined, yet. Therefore, first, this paper report the method of measuring the pH of high porous concrete. Secondly this paper reports the pH reduction of high porous concrete to grow plants.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.181-182
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• 2016

We developed eco-friendly lightweight concrete in order to apply eco-friendly lightweight concrete into structural wall or slab of shallow depth urban railway system. However, since lightweight aggregate has different structural feature of porous and it has been overvalued at current KS standard when applied, we did compare the characteristics of freezing and thawing of normal weight aggregate concrete by comparative test method(KS, ASTM). According to test method, there was a big difference of dynamic elastic modulus in lightweight concrete rather than in normal weight aggregate concrete. The big absorption factor in lightweight aggregate is main reason for that. For more detail, in KS law in which only 14 days water curing is carried out, the big amount of moisture in lightweight aggregate is frozen and high heaving pressure occurs and finally that lead to destruction of lightweight concrete. Therefore, it is considered that in case of lightweight concrete, resistibility against freezing and thawing has been undervalued in domestic KS law compared to ASTM law, which is overseas standard. So, a variety of examination about testing criteria and rule would be necessary for exact assessment of lightweight concrete.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.7
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• pp.47-53
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• 2004

Permeable polymer concrete can be applied to roads, sidewalks, river embankments, drain pipes, conduits, retaining walls, yards, parking lots, plazas, interlocking blocks, etc. This study was to explore a possibility of using blast furnace slag powder and stone dust of industrial by-products as fillers for Eco-permeable polymer concrete. Different mix proportions were tried to find an optimum mix proportion of the Eco­permeable polymer concrete. The tests were carried out at $20{\pm}1^{circ}C$ and $60{\pm}2\%$ relative humidity. At 7 days of curing, unit weight, coefficient of permeability, dynamic modulus of elasticity, compressive, flexural and splitting tensile strengths ranged between $1,821{\~}1,955 kg/m^{3}$, $0.056{\~}0.081\;cm/s$, $114{\times}0^{2}{\~}157{\times}10^{2}\;MPa,\;17.6{\~}24.7\;MPa,\;5.98{\~}7.94\;MPa\;and\;3.43{\~}4.70\;MPa$, respectively. It was concluded that the blast furnace slag powder and stone dust can be used in the Eco-permeable polymer concrete.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.5
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• pp.79-87
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• 2002

This study is performed to examine the physical and mechanical properties of Eco-concrete using rice straw ash for planting. The tests for void ratio, compressive and bending strength with neutralization treatment point, curing condition and coarse aggregate size are performed. The test result shows that the void ratio is decreased with increasing content of rice straw ash. But, the compressive and bending strength are increased with increasing content of rice straw ash. The greatest strength is appeared when neutralization is treated in curing age of 6 days. These Eco-concrete is very useful for planting.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.2
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• pp.59-66
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• 2006

This study is performed to evaluate freezing and thawing properties of polypropylene fiber reinforced eco-concrete using soil, natural coarse aggregate, soil compound and polypropylene fiber. The mass loss ratio is decreased with increasing the content of natural coarse aggregate and soil compound, but it is increased with increasing the content of polypropylene fiber. The ultrasonic pulse velocity, dynamic modulus of elasticity and durability factor are increased with increasing the content of natural coarse aggregate and soil compound, but it is decreased with increasing the content of polypropylene fiber. The mass loss ratio, ultrasonic pulse velocity, dynamic modulus of elasticity and durability factor are $1.49{\sim}3.32%,\;1,870{\sim}2,465\;m/s,\;77X10^2{\sim}225X10^2\;MPa\;and\;84.6{\sim}92.8$ after freezing and thawing 300 cycles, respectively. These eco-concrete can be used for environment-friendly side walk and farm road.