• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.273-274
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• 2018

When IGCC Slag(CGS) aggregate was used as PHC-Pile, the moldability was lowered as the mixing ratio increased. concrete mix design. Also the mix characteristics increased the use of AD depending on the usage rate, however, require detailed consideration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.27-28
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• 2023

This study compared and analyzed the fluidity, compressive strength, and carbonation resistacne of amorphous metal fiber reinforced mortar according to the PCC mixing ratio as part of a study to improve the self-healing performance and tensile performance of concrete structures.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1786-1792
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• 2011

If the concrete track is settled excessively, it must be restored or reinforced immediately. Especially, reinforcement/restoration method should be applied without affecting on train operation. To deal with this problem, special equipment, process and material should be prepared. This paper suggest a special mixing ratio to restore the settled concrete track. Materials are classified the quick hardening mortar and the middle hardening mortar. The quick hardening mortar is used to restore the settled track and the middle hardening mortar is used to fill the void. These materials must have the appropriate gel time(1-40sec) and compressive strength($5kg/cm^2$). Various compounds is used and the micro cement is used as a main base.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.89-92
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• 1999

The purpose of this study is to evaluate the capability to use with cement admixture materials because Paper Sludge Ash consists of Si, Ca and Al which are chief content in Pozzolan. For the derivation of Pozzolanic reaction in Paper Sludge Ash, it is measured compressive strength on cement mortar which is replaced mixing of Paper Sludge Ash and inorganic admixture ; ie, gypsum, lime and slaked lime, regularly. In the result of test, the strength decrease remarkably when cement is only replaced with Paper Sludge Ash, but the strength is almost equal when cement is replaced with Paper Sludge Ash is mixed with inorganic admixture material in proportions of 5~15%. Consequently, It is possible to use Paper Sluge Ash with admixture materials of cement.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.85-88
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• 1999

We tested the limestone powder as a filler powder for the effective use of slag cement. Hydration process were investigated by measuring the thermal differential analysis(DTA), compressive strength, XRD patterns, calorimeter of slag cement-limestone powder paste prepared by mixing limestone powder-slag cement. The results obtained in this study, there were no significant difference between the cases of adding up to 5% limestone powder, but the reaction time was accelerated. Also the compressive strength was increased for adding up to 5% limestone powder. The min hydrated paste products were Ca(OH)2 and calcium silicate hydrates. In the case of mixed limestone powder peak appear tricalcium carboaluminate hydrate in the sample of 7 days hydration.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.263-268
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• 2001

In this study, the physical and mechanical characteristics of Bottom-ash exhausted from each of steam power plant was considered. The comparative objects were Bottom-ash in which a lot of powder contained and that in which less than that relatively contained. The difference in quantity of powder showed different effect on the character of flow. This study was undertaken on the use of Bottom-ash as a fine aggregate, and showed the optimum mixing and the character of flow according to each rate. And this study showed the quantity of water and binder added in different Bottom-ash was differently used.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.101-102
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• 2012

In this study, it was evaluated about hydration heat reduction under hot weather condition. Placement temperature set 25℃ and 35℃, For hydration heat reduction was applied such as FA and BFS. As a results, mixture of BFS70% is the most effective hydration temperature reduction.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.997-1002
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• 2001

Tensile strength of CFRP (Carbon Fiber Reinforced Polymer) is approximately 10 times higher than that steel reinforcement, but the design strength of CFRP is normally reduced by the bond failure between RC and CFRP. Many researches have been carried out, concerned with bond behavior between RC and CFRP to prevent the unpredicted bond failure of RC beam strengthened by CFRP, but the national design code for design bond strength of CFRP hasn't been constructed. In this study, 3 beams specimen strengthened by CFRP under the variable of bonded length were tested to derive the design bond strength of CFRP to the RC flexural members. Also 2 beams specimen strengthened by CFRP were tested to inspect the construction environment effects such as mixing error of epoxy resin and the amount of primer epoxy resin. From the test results, It is concluded that the maximum design bond strength of CFRP to RC flexural member is considered to be $\tau_{a}$=8kgf/$cm^{2}$.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.311-316
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• 2002

The following results are achieved from a mortar flow test depending on stainless steel slag fineness, rate of replacement, and a research on material age compressive strength, strength activity index. 1. Flow is proportional to the stainless steel slag fineness. 2. Mixing stainless steel slag decreases compressive strength 3. Material age compressive strength has the maximum value when stainless steel slag fineness is 6000$cm^2$/g. 4. Material age 7day strength activity index satisfies KSCE 95-01 at all conditions except the case of fineness 8000$cm^2$/gㆍstainless steel slag rate of replacement 30%. 5. Material age 28day strength activity index satisfies KSCE 95-01 in case of stainless steel slag fineness 4000$cm^2$/gㆍrate of replacement 10%, fineness 6000$cm^2$/gㆍ10%, or 20%.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.28-31
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• 2004

This paper discusses the role of micro and macrofibers in the workability, compressive strength, and failure of cementitious composites. Workability(flow), compressive strength, splitting strength and fracture mechanism of hybrid fiber reinforced cement composites(HFRCC) have been investigated by means of Korean Standard (KS). The specific blend pursued in this investigation is a combination of polyvinyl alcohol(PVA) and steel cord. It was demonstrated that a hybrid combination of steel and PVA enhances fiber dispersion compared to only steel cord reinforced cement composites and that the brittle and wide cracking was much reduced in HFRCC as expected because in the matrix containing the PVA fiber around the steel cord, a multiple microcracking occurred and the steel cord could sufficiently work for bridging the cracked surface.