• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4542-4551
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• 2013

Recently, much attention has focused on the study of eco-friendly concrete using recycled by-products for protecting marine ecosystem and durability of concrete exposed to marine condition. This study evaluated the durabilities of 4 different type of concrete mixtures(Control, Marine, Porous, New slag) with the seawater resistance by marine environment exposure experiment and freeze-thaw resistance, resistance to chloride ion penetration considering severe deterioration environment. In this study, we conducted seawater resistance using compressive strength according to the age(7/28/56 days) of specimen and curing conditions(standard(fresh water), tidal, immersion, artificial seawater). The results show that compressive strength of concrete exposed to marine environment exposure condition was lower than those of the standard curing condition. Also, compressive strength of New slag using eco-friendly materials for protecting marine ecosystem was lower than those of other concretes, there is need to improve the performance of New slag. The results for freeze-thaw resistance showed that all mixtures have excellent, but the Porous and New slag were lower than others. Also, the more improved resistance to chloride ion penetration than those of the Marine was measured in the New slag regardless of curing condition.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.4
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• pp.307-313
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• 2014

Recent interest in the increased structural performance and durability evaluation of this concrete structure in a salt damage environment is increasing. The most secure and reliable method of accelerated corrosion test is a method to carry out the rebar corrosion monitoring can be exposed directly to the marine test site exposure. However, long-term exposure testinghas the disadvantage that a long period is necessary. So, a lot of research on RC of salt damage environment have beenpromoted as alternatives to replace this. However, accelerated corrosion test, in the short term only is appropriate and is but an accelerated test method to evaluate the critical chlorine concentration, there is a difficult problem that you still get the answer. It is one of the correlation problems accelerated test correspond to a certain period of exposure environment. Therefore, in this study, to clarify the differences rebar corrosion beginning, through the actual corrosion accelerated test in corrosion time and laboratory test chamber of the structure of the marine environment results in both environments, it is an object of correlation coefficient derived.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.773-776
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• 2008

The corrosion of steel in concrete is significant in marine environment. Marine bridges are readily deteriorated due to the exposure to marine environment. Salt damage is one of the most detrimental causes to concrete bridges and port structures. Especially, the splash and tidal zones around water line are comparatively important in terms of safety and life-time point of view. During the last several decades, cathodic protection (cp) has been commonly accepted as an effective technique for corrosion control in concrete structures. Zn-mesh sacrificial anode has been recently developed and started to apply to the bridge column cp in marine condition. The detailed parameters regarding Zn-mesh cp technique, however, have not well understood. This study is to investigate how much Zn-mesh cp influences along the concrete column at elevated temperature. About 100cm column specimens with eight of 10cm segment rebars have been used to measure the variation of cp potential with the distance from Zn-mesh anode at both 10$^{\circ}$C and 40$^{\circ}$C in natural seawater. The cp potential change and current diminishment along the column specimens have been discussed for the optimum design of cp by Zn-mesh sacrificial anode

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.67-74
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• 2015

RC (Reinforced Concrete) structures are considered as cost-benefit and durable however performances of structural safety and durability are degraded due to steel corrosion. Service life in RC structure is differently evaluated due to different local environmental conditions even if it is exposed to the same chloride attack. In the paper, 25 concrete cores from field investigation are obtained from 4 RC columns with duration of 3.5~4.5 years exposed to sea water. Through total chloride content measurement, surface chloride contents and apparent diffusion coefficients are evaluated. Service life of the target structure is estimated through deterministic method based on Fick's $2^{nd}$ Law and probabilistic method based on durability failure probability, respectively. Probability method is evaluated to be more conservative and relatively decreased service life is evaluated in tidal zone and splash zone over 40.0 m. Chloride penetration behavior with coring location from sea level and the present limitations of durability design method are investigated in the paper.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.730-737
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• 2014

In this study, chloride content of marine concrete bridge at the south coast in 5~34years was calculated based on the measured data and the validity of the proposed value was evaluated. Also, correlation of existence of salt injury prevention coating, chloride content, carbonation depth and the compressive strength of marine concrete bridges were derived and relationship of the four was evaluated. According to the research results, surface chloride content value in the tidal zone proposed form KCI 2009 and value in the splash zone and atmospheric zone proposed form Cheong et al.(2005) was the most valid. Also, salt injury prevention coating of marine concrete bridges had the outstanding effect of preventing chloride content penetration, carbonation depth and reduction in the compressive strength. Compressive strength of concrete was reduced by the increase of carbonation depth and chloride content.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.13-21
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• 2023

In this study, the coastal airborne chlorides were investigated in the Incheon Port, South Korea. Monthly measurements of coastal airborne chlorides were taken for a total of 2 years from September 2021 to August 2023 at 15 locations in North, South, and New Port. We analyzed the distribution characteristics of airborne chloride based on port facilities and measurement environments, as well as the reduction characteristics of the airborne chloride with respect to coastal distance. As a result, the monthly distribution range of the airborne chloride in the North, South, and New Port varied similarly, ranging from 0.4 to 3.3 mdd. Due to the influence of seasonal winds considering the direction of the coastline, both the North Port and South Port had higher the airborne chloride in winter, while the New Port had higher content in summer. The airborne chlorides were higher at locations inside an inland sea compared to those outside an inland sea. This is because the wind coming from the sea passed through the inland sea. Even in the same region with identical coastal distances, there were variations in airborne chloride levels depending on the height above the ground. In tidal zone, the monthly airborne chlorides were significantly higher in the lower part than in the upper part. The rate of decrease equation of airborne chlorides for each port based on the distance from the coastline was derived, and the results showed that as the distance from the coastline increased, the rate of decrease in airborne chlorides was the highest for New Port and the lowest for South Port.