• Title/Summary/Keyword: In-situ 탄산화

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Evaluating the Effectiveness of In-Situ Carbonation in Floor Dry Cement Mortar Applications (바닥용 건조시멘트 모르타르 배합 내 In-situ 탄산화 적용을 위한 CO2 주입 특성 및 물리적 특성 검토)

  • Kim, Jin-Sung;Cho, Sung-Hyun;Kim, Chun-Sik
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.1
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    • pp.1-10
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    • 2024
  • In-situ carbonation technology represents a form of mineral carbonation that integrates CO2 into the fabrication process of cementitious construction materials, capturing CO2 as calcium carbonate(CaCO3) through a reaction between calcium ions(Ca2+) and CO2 released during cement hydration. This investigation examines the application of in-situ carbonation technology to a variety of floor dry cement mortar formulations commonly used in local construction projects. It assesses the effects of varying the CO2 injection flow rate and total volume of CO2 injected. Additionally, the study evaluates the impact of reducing the quantity of cement used as a binder on the final product's quality.

Probabilistic Estimation of Service Life of Box Culvert for Power Transmission Considering Carbonation and Crack Effect (탄산화와 균열을 고려한 전력구 콘크리트 구조물의 확률론적 수명 예측)

  • Woo, Sang-Kyun;Lee, Yun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.6
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    • pp.30-40
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    • 2014
  • The demand of underground structure such as box culvert for electric power transmission is increasing more and more, and the service life extension of these structures is very important. Recent observations in field and experimental evidences show that even steel in concrete can be corroded by carbonation reaction of cover concrete. Carbonation-induced corrosion in concrete may often occur in a high carbon dioxide environment. In this study, the risk of carbonation of box culverts in our nation was evaluated by measuring the carbonation rate and concrete cover depth in field. Then, the service life due to carbonation at the cover depth was calculated by in situ information and the Monte Carlo simulation in a probabilistic way. Additionally, the accelerated carbonation test for the cracked beam specimen was executed and the crack effect owing to the carbonation process on the service life of box culvert was numerically investigated via Monte Carlo simulation based on the experimental results.

Estimation of Carbonation and Service Life of Box Culvert for Power Transmission Line (박스형 전력구의 콘크리트 탄산화에 의한 잔존수명 예측)

  • Woo, Sang Kyun;Lee, Yun;Yi, Seong Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.4
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    • pp.116-121
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    • 2012
  • The construction of underground structures such as box culverts for electric power transmission is increasing more and more, and the life extension of these structures is very important. Carbonation-induced corrosion in concrete may often occur in a high carbon dioxide environment. In this study, the risk of carbonation of two concrete box culverts in an urban area was evaluated by measuring the carbonation rate and concrete cover depth. Then, the carbonation-free service life at the depth of the steel was calculated, based on in situ information, by the Monte Carlo simulation. The service life of box culvert due to carbonation was estimated over 250 years via Monte Carlo simulation.

An Empirical Estimation Procedure of Concrete Compressive Strength Based on the In-Situ Nondestructive Tests Result of the Existing Bridges (공용중 교량 비파괴시험 결과에 기반한 경험적 콘크리트 압축강도 추정방법의 제안)

  • Oh, Hong-Seob;Oh, Kwang-Chin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.4
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    • pp.111-119
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    • 2016
  • Rebound hammer test, SonReb method and concrete core test are most useful testing methods for estimate the concrete compressive strength of deteriorated concrete structures. But the accuracy of the NDE results on the existing structures could be reduced by the effects of the uncertainty of nondestructive test methods, material effects by aging and carbonation, and mechanical damage by drilling of core. In this study, empirical procedure for verifying the in-situ compressive strength of concrete is suggested through the probabilistic analysis on the 268 data of rebound and ultra-pulse velocity and core strengths obtained from 106 bridges. To enhance the accuracy of predicted concrete strength, the coefficients of core strength, and surface hardness caused by ageing or carbonation was adopted. From the results, the proposed equation by KISTEC and the estimation procedures proposed by authors is reliable than previously suggested equation and correction coefficient.

Research on manufacturing secondary construction products using in-situ carbonation technology (In-situ 탄산화 기술이 적용된 콘크리트 2차제품 제조 연구)

  • Hye-Jin Yu;Sung-Kwan Seo;Woo-Sung Yum
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.33 no.6
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    • pp.226-233
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    • 2023
  • In this study, the basic physical properties and microstructure of concrete interlocking blocks with amount of different CO2 gas injection were analyzed according to determine the applicability of In-situ carbonation technology to construction secondary products. The amount of carbon dioxide gas injection was selected as 0, 0.1, 0.3, 0.5, 0.7 wt.% compared to cement amount. A lab-scale press equipment was designed to apply developed carbonation technology to real construction site. And mixer for stable CO2 gas injection was designed. Using the designed devices, CO2 gas injected samples were created and physical property of samples were performed. As a result of the physical property test, as the CO2 injection amount increased to 0.3 %, it showed higher strength behavior compared to the original mix. And more than 0.5 % samples showed lower strength behavior than original sample, but they satisfied the standard of concrete interlocking block. This results were determined that CO2 injection contributed to the creation of hydrates such as C-S-H. Therefore, the possibility of applying carbonation technology, which injects CO2 during mixing, to various secondary construction products was confirmed.

A Long-term Durability Prediction for RC Structures Exposed to Carbonation Using Probabilistic Approach (확률론적 기법을 이용한 탄산화 RC 구조물의 내구성 예측)

  • Jung, Hyun-Jun;Kim, Gyu-Seon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.5
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    • pp.119-127
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    • 2010
  • This paper provides a new approach for durability prediction of reinforced concrete structures exposed to carbonation. In this method, the prediction can be updated successively by a Bayes' theorem when additional data are available. The stochastic properties of model parameters are explicitly taken into account in the model. To simplify the procedure of the model, the probability of the durability limit is determined based on the samples obtained from the Latin Hypercube Sampling(LHS) technique. The new method may be very useful in design of important concrete structures and help to predict the remaining service life of existing concrete structures which have been monitored. For using the new method, in which the prior distribution is developed to represent the uncertainties of the carbonation velocity using data of concrete structures(3700 specimens) in Korea and the likelihood function is used to monitor in-situ data. The posterior distribution is obtained by combining a prior distribution and a likelihood function. Efficiency of the LHS technique for simulation was confirmed through a comparison between the LHS and the Monte Calro Simulation(MCS) technique.

Chlorination of Alcohols Using Potassium Carbonate and Silicon Tetrachloride (탄산칼륨 존재하에서 사염화규소를 이용한 알코올의 염소화반응)

  • Ha, Dong Soo;Kim, Hyeung Ae
    • Journal of the Korean Chemical Society
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    • v.41 no.10
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    • pp.535-540
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    • 1997
  • Potassium carbonate reacts with silicon tetrachloride to form trichlorosilyloxy carbonylchloride which reacts subsequently with another molecule of silicon tetrachloride leading to phosgene eventually in chlorinated solvents. This in situ generated trichlorosilyloxy carbonylchloride or phosgene were found to be very effective for the chlorination of a wide variety of alcohols to the corresponding chlorides. Primary, secondary and benzylic alcohols were converted into corresponding chlorides when treated with silicon tetrachloride in the presence of potassium carbonate at room temperature.

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