• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.4
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• pp.314-320
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• 2014

Although the cement industry serves as the cornerstone of the construction industry by supplying one of its fundamental materials, it confronts new environmental challenges due to the problem of the $CO_2$ generated from raw materials and fuel used in the cement manufacturing process. Also, concrete structures can be decomposed and reused as construction materials. Simply in terms of the cyclic processing of $CO_2$, recycling waste concrete to manufacture recycled aggregate or recycling waste concrete powder, which is the material for cement can be considered optimally environment-friendly practices. This study contributes to the aim of manufacturing high value added materials that exploits the chemical properties of the waste concrete powder. From the research results, waste concrete powder is feasible to use to produce low carbon type recycled cement.

• 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 Korea Concrete Institute Conference
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• 2008.11a
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• pp.765-768
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• 2008

The prevent methods of Alkali-Silica Reaction (ASR) are studying after the failure cases by ASR were reported in Korea. When ASR failure is causing to the step of maintenance, the available repair methods were rarely studied in the World. In this study, premixed fly ash cement was applied to prevent ASR in the concrete pavement. The ratio of fly ash and cement is 20 percent and 80 percent by weight of total cementious material. The construction performance of premixed fly ash cementious concrete pavement was studied that the application is verify to performance collected data during the constructing in the field. The freeze-thaw test was studied to verify durability of the premixed fly ash cementious material made specimen in the laboratory. The results show that construction performance and durability are well condition in this test section and freeze-thaw test.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.285-292
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• 1998

This study was performed to evaluate the engineering properties of concrete using normal portland cement, natural aggregates and rice-straw ash. The following conclusions were drawn; 1. The unit weight was in the range of $2,250{\sim}2,335kgf/m^3$, the weights of those concrete were decreased 1~5% than that of the normal cement concrete, respectively. 2. The highest strength was achieved by 5% rice-straw ash filled rice-straw ash concrete, it was increased 17% by compressive strength, 30% by tensile strength and 21% by bending strength than that of the normal cement concrete, respectively. 3. The ultrasonic pulse velocity was in the range of 4,059~4,360m/s, which was showed about the same compared to that of the normal cement concrete. The highest ultrasonic pulse velocity was showed by 5% rice-straw ash filled rice-straw ash concrete. 4. The acid-proof was increased with increase of the content of rice-straw ash. The acid-proof was increased 1.15 times by 5% rice straw ash, 1.45 times by 10%, 1.6 times by 15% rice-straw ash filled concrete than that of the normal cement concrete, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.289-290
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• 2009

In this study, the resistance of calcium aluminate cement (CAC) against chloride-induced corrosion was assessed by testing for the strength, chloride transport, and corrosion behaviour. The study found that the CAC concrete had better performance than ordinary Portalnd cement(OPC) in resisting the corrosion of steel.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.329-330
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• 2009

This study is to investigate the effect of the combined use of fly ash(FA) and coarse particle cement(CC) collected in particle classification process of ordinary Portland cement(OPC) manufacturing on the hydration exothermic and strength development in the field application.

• Cement
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• s.76
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• pp.64-73
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• 1979

• Cement
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• s.30
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• pp.80-82
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• 1969

• Cement
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• s.164
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• pp.51-53
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• 2004

• Cement
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• s.164
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• pp.44-50
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• 2004