• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.146-147
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• 2014

In this study, as the resistance of the carbonation for high volume admixture incorporating concrete, coating effect of using refined cooking oil in the surface of high volume admixture incorporating concrete has been tested. The following results could be made as the conclusion. For the fresh concrete, the slump and air content has been identified as satisfying the target range. For the hardened concrete, comparing with specimen of Plain, specimen with coating showed better long age compressive strength. For the carbonation speed, the specimen of FA30 showed highest speed and the specimen of BS60 showed higher speed than specimen of Plain. For all the specimens coated with RCO, as the decrease of capillary pores inside the concrete, the carbonation speed has been obviously decreased and with even better effect than using PEP coating. It could be identified that specimens with coating by RCO showed good effect on refrain the speed of carbonation.

• Journal of the Korea Concrete Institute
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• v.21 no.4
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• pp.449-455
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• 2009

The increase of industrial carbonic dioxide emissions has accelerated the carbonation of reinforced concrete structures, which drops off their durability. Although advanced countries have already taken safety control measures against the carbonation of RC structures, it is still difficult now to accurately predict the actual carbonation depth. Additionally, it requires much time and efforts. Recently, it is possible to get the data more rapidly through accelerated carbonation test with the $CO_2$ concentration of 100%. In this paper, the carbonation test results obtained by two test methods such as the normal carbonation test method and the accelerated carbonation test method, were compared to investigate the carbonation characteristics of fly ash concrete. The accelerated carbonation test on concrete specimens with the pre-curing age of 180 days was also carried out to examine the carbonation characteristics of fly ash concrete at long-term age. Consequently, fly ash concrete at early age was vulnerable to carbonation and however, its carbonation resistance at long-term ages was improved compared with OPC concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.3-4
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• 2015

Environmental load reduction and sustainable development one of the study's research into the available material is discharged, remove the coarse aggregate and fine aggregate from waste concrete and utilizing the remaining cement fine powder as an alternative raw material for limestone is the main raw material of cement developing playback cement that was the purpose. Physical over existing research and chemical quality was confirmed was evaluated for durability by promoting carbonation test, research studies on the durability evaluation insignificant. As honipyul within the aggregate differential lung fine powder increases carbonation resistance performance've found that increased sharply and, S0 showed fairly similar to the OPC. Therefore, the development within the technology research to separate fine aggregate discharge fully differential and waste fine powder is determined to be the development and use of the playback durability of the cement with the carbonation levels corresponding to the OPC if made.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.23-24
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• 2015

As this study is an experiment for solving problem on the carbonation acceleration of high volume admixture concrete, the capillary pore getting filled up by saponification as cooking oil gets absorbed to the concrete surface in case of applying a cooking oil based coating agent to the concrete has been verified in the previous studies. Accordingly, this study has performed a comparative experiment on the cooking oil and the anticorrosive coating agent sold on the market while the result followed by this experiment has shown the fact of indicating similar carbonation penetration depth and porosity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.192-193
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• 2022

In this study, concrete durability was reviewed before CGS, a by-product generated from IGCC, was used as a fine aggregate for concrete. The characteristics of concrete and effect on carbonization according to the type of pre-mixed cement and the CGS substitution rate were analyzed. As a result of the analysis, the depth of carbonation according to the pre-mixed cement types increased by up to 52%, and the carbonation resistance tended to be similar overall when CGS was used as a fine aggregate.

• Journal of the Korea Institute of Building Construction
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• v.22 no.5
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• pp.425-430
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• 2022

Concrete used for the foundation of high-rise buildings is often placed through in an integrated pouring to ensure construction efficiency and quality. However, if concrete is placed integrally, there is a high risk of temperature cracking during the hydration reaction, and it is necessary to determine the optimal mixing design of high-performance, high-durable concrete through the replacement of the admixture. In this study, experiments on salt damage, carbonation, and sulfate were conducted on the specimen manufactured from the optimal high-performance low-heating concrete combination determined in the author's previous study. The resistance of the cement matrix to chlorine ion diffusion coefficient, carbonation coefficient, and sulfate was quantitatively evaluated. In the terms of compression strength, it was measured as 141% compared to the structural design standard of KCI at 91 days. Excellent durability was expressed in carbonation and chlorine ion diffusivity performance evaluation. In particular, the chlorine ion diffusion coefficient, which should be considered the most strictly in the marine environment, was measured at a value of 4.09×E-12m²/y(1.2898×E-10m²/s), and is expected to be used as a material property value in salt damage durability analysis. These results confirmed that the latent hydroponics were due to mixing of the admixture and high resistance was due to the pozzolane reaction.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.580-583
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• 2004

Due to the tendency of increase in demolished-concrete produced by alteration and deterioration of concrete structures, recycling of those demolished-concrete is necessary to solve the exhaustion of natural aggregate, in order to save resources and protect environment. In this an experimental study herein, the Chlorine-ion and Carbonation resistance of the recycled aggregate concrete was investigated. Coarse aggregate was replaced with $100\%$ of the recycled aggregate and cement and fine recycled aggregate was replaced with various amount. It was shown that the concrete can obtain resistance of chlorine-ion, when fly ash replaced with up to $30\%$ of cement.

• Journal of the Korean Professional Engineers Association
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• v.14 no.4
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• pp.15-25
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• 1981

Electrical behaviors of the divalent silver oxide-zinc cell were analyzed for imporving capacity and keeping electrodes from passivation or sharp increases of cell internal resistance in the course of discharge. One of primary factors in relation to lowering performance can be depicted by cell internal resistance increase being created by various routes, first by insufficiency and/or the carbonation of the electrolyte, secondly by barrier blockage, thirdly by electrode passivation which are due to improper material use of wrong processing, and by gassing as fourth cause. The carbonation causes electrobyte to have impedance up as well as poor amalgamation, resulting in vigorous corrosion reaction of copper plated inner top, evolving hydrogen gas. Electrical characteristics of the cell was reviewed to elucidate relationships between the discharge capacity and the cell internal resistance.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.423-426
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• 2005

Until now, the quantity to recycle wasted concrete as the great supplementary value was very little. But considering a insufficiency of the present state of aggregates, the recycling of wasted aggregates is indispensable. Recycled aggregate is useful resources for concrete, but its application to structural member is not frequently. In this an experimental study here in, this study is to reinforcement orientation containing fiber of the spun-concrete using recycled aggregate, evaluation of designed chlorine-ion and carbonation resistance. The result of study chlorine-ion resistance by using replacement ratios ($0.00\%,\;0.01\%,\;0.03\%,\;0.05\%,\;0.08\%$) of fiber which it more increase. Carbonated thickness of the spun-concrete used fiber and the normal spun-concrete was similar or it appeared with the tendency which it diminishes.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.161-166
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• 1998

The main object of this study is to examine the basic properties of fresh concrete as well as hardened concrete using several types of cement such as ordinary portland cement, sulphate resisting portland cement, blast furnace slag cement, ternary blended cement. In addition, effects of each cement on the durability including drying shrinkage, freeze-thawing resistance, resistance of chloride ion penetration, carbonation of concrete were investigated. As the results of this study, it was proved that most of the properties of concrete using each cement were similar, but there were some differences in bleeding, setting time, resistance of chloride ion penetration and carbonation.