• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.15-16
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• 2023

In this paper, we aimed to develop a new method for diagnosing the depth of neutralization in architectural and civil engineering structures using the core drilling method, which combines the speed of drilling with the accuracy of core ringing. When compared to the drilling method, the core drilling method showed a lower measurement deviation of 1-2mm (7.6%) in confirming the depth of neutralization. This is believed to be a result of potential interference during the sample collection process in the drilling method, where the drill may pass through aggregates, leading to overestimation, as indicated in previous studies. The rapid evaluation of neutralization using the core drilling method serves as an alternative to address the issues associated with both drilling and core ringing methods in diagnosing the depth of neutralization. It offers a solution to the inaccuracy caused by coarse aggregates and the cumbersome post-processing steps required for neutralization diagnosis. Our proposed technique aims to provide an accurate and expedited diagnosis of neutralization depth without the need for additional processes.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.3
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• pp.59-64
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• 2003

Hwangto would be an environment-friendly material that can be readily used. The purpose of this study is to obtain the absorption ratio, ultrasonic pulse velocity and neutralization of the mortar with non-active Hwangto and stone dust. The absorption ratio and neutralization depth are increased with increase of non-active Hwangto. But, the ultrasonic pulse velocity is decreased with increase of non-active Hwangto. In results of SEM analysis, the crystals are increased with increase of non-active Hwangto.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.177-185
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• 1999

In this study, study about fly ash and blast-furnace slag used as substitutive materials for cement, and the influence on the neutralization of high flow concrete durability with these substitutive materials was performed and analyzed. The results are as follows 1) Aggregate segregation was partially improved with the progress of the admixture input at the mix proportion above slump flow 65 cm 2) Compressive strength with the progress of the increasement of fly ash input was decreased in early age, but decrease range was improved in long term age. Also, in case of blast-furnace, similar or improved compressive strength was appeared. 3) The neutralization depth with fly ash input was noticeably increased. But blast-furnace slag was effective to prevent. 4) In this experiment, high powder content was advantageously affected on preventive effect of the neutralization, and the relationship between the compressive strength and the neutralization depth was inversely proportional.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.69-74
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• 2003

This study evaluated durability through measurement of substituted test piece's pH degree and experiments of neutralization. Comparing and evaluating cared test piece's pH degrees which we got before the neutralization and after the neutralization. After evaluating neutralization depth through neutralization, evaluating neutralization properties by Fly Ash replacement ratio. pH degree was decreased by cement replacement ratio of Fly Ash. And in the case of substitution of the same amount of Fly Ash, fine aggregate replacement ratio was increased. When the test piece, which had been cared in high temperature, was promoted to neutralization, Among the test piece which was replaced with Fly Ash 40%, the test piece which has high rate of fine aggregate proved opposition of neutralization Through the test, Ⅰ summarized that the test piece cared in high temperature was mostly effected by compress strength, the test piece cared in low temperature was mostly effected by pH degree.

• International Journal of Concrete Structures and Materials
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• v.6 no.3
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• pp.155-163
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• 2012

In order to predict the neutralization of concrete which is the reaction of carbonation dioxide from the outside and cement hydration product, such as calcium hydroxide and C-S-H, it was studied the numerical analysis method considering change of the pore structure and relative humidity during the neutralization reaction. Diffusion-reaction neutralization model was developed to predict the neutralization depth of concrete with coating finishing material. In order to build numerical analysis models considering outdoor environment and finishing materials, the adaption of proposed model was shown the results of existing outdoor exposure test results and accelerated carbonation test.

• Journal of the Korean Society of Safety
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• v.28 no.6
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• pp.29-35
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• 2013

The purpose of this study is to investigate the steel bar corrosion and degree of reinforced concrete bridge, and analyze the cause of corrosion occurrence. Therefore they could ensure the durability and stability as to suggest the corrosion prevention of reinforced concrete structure. To study the corrosion state reinforced concrete structure, We investigate the cover of concrete, the compressive strength by schmidt hammer, the neutralization test of site, the compressive strength of core and the measurement of neutralized depth. As the results of test, the corrosion-grade of reinforced concrete structure which the degree of corrosion is 3, 4 degree get to 18% in the used time of 40 years and the time elapsed of 25 years. Therefore the corrosion of steel bar give rise to public discussion. The degree of corrosion is serious, and the neutralization come to the cover of concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.561-564
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• 2006

This study is aimed for investigating the engineering properties of concrete containing fly ash, slag powder and limestone powder. The results of this study are as follows; As limestone powder is incresed, slump, air loss and strength is reduced, variation ratio of length is reduced, dynamic modulus of elasticity and neutralization depth is incresed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.43-46
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• 2009

The purpose of this study is to enhance durability of concrete structures that uses this surface protecting material by carrying out the performance test of the surface protecting material of concrete, and as s result, we reached out the conclusion as follow. 1. As a result of the test measuring the stability and adhesive power of conductive film against ultraviolet, freezing & thawing, and damage from seawater that deteriorate the surface protecting material, it was turned out to meet the performance criteria specifying in the KS standard enough to gain a good evaluation to use as a surface protecting material. 2. As a result of the test identifying the neutralization-furtherance, it was assessed to be capable of protecting effectively concrete structures from carbonic acid gas by a very low depth of 0.1mm of neutralization. 3. As a result of the test identifying Penetrated Resistance Properties of chloride ion, as it was turned out to have a very low value of 819 Coulombs, it was assessed that even in the environment where the corrosion by chloride such sea environment is very affective, the film can effectively protect the concrete structure. 4. As a result of the test identifying freezing & thawing, as there was no change in reduction of mass after 400 cycle, it was assessed that the film has a good resistance against freezing & thawing. According to the results of study above, it is expected that this technology can extend its durability of concrete structure and be widely used for concrete structure through means (methods) to prevent the neutralization and damage from seawater as original purposes of the surface protecting material.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.4
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• pp.163-171
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• 1999

In this study, we executed fundamental experiment to investigate properties of accelerated carbonation with changing chloride content of concrete used sea sand in order to examine durability. So we obtained the results of following properties of mechanics, durability, concrete with sea sand, determined concrete w/C 30%, 40%, 50%, and fine aggregate 40% and changing containing chloride 0, 0.3, 0.6, $0.9kg/m^3$ by the experiment of accelerated neutralization. The results of this study as follows: 1) As result of changing chloride content of concrete used sea sand augmented in stages $0.3kg/m^3$, accelerated carbonation was increased as increment chloride content. The increment depth was decreased as it went long term age. It was shown the chloride content effected increment of carbonation depth in concrete 2) As a result of changing W/C of concrete used sea sand augmented in stages 10% at a time from 30% to 50%, accelerated carbonation depth of concrete was increased as W/C ratio. 3) As the carbonation concrete used sea sand, compressive strength between 8 weeks and accelerated carbonation depth of 1 weeks, 2 weeks, 4 weeks, 8 weeks was inversion proportion.

• Ocean Systems Engineering
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• v.11 no.4
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• pp.331-351
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• 2021

Underwater images are very much different from images taken on land, due to the presence of a higher disturbance ratio caused by the presence of water medium between the camera and the target object. These distortions and noises result in unclear details and reduced quality of the output image. An underwater image restoration method is proposed in this paper, which uses blurriness information, background light neutralization information, and red-light intensity to estimate depth. The transmission map is then estimated using the derived depth map, by considering separate attenuation coefficients for direct and backscattered signals. The estimated transmission map and estimated background light are then used to recover the scene radiance. Qualitative and quantitative analysis have been used to compare the performance of the proposed method against other state-of-the-art restoration methods. It has been shown that the proposed method can yield good quality restored underwater images. The proposed method has also been evaluated using different qualitative metrics, and results have shown that method is highly capable of restoring underwater images with different conditions. The results are significant and show the applicability of the proposed method for underwater image restoration work.