• Title/Summary/Keyword: concrete durability.

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A Study on Evaluation of Complex Deterioration evaluation and Prediction of Residual Life through Concrete Core (콘크리트 코어 분석을 통한 복합열화 평가와 잔존수명 예측 연구)

  • Shim, Jaeyoung
    • Journal of the Society of Disaster Information
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    • v.13 no.3
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    • pp.332-339
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    • 2017

  • In the case of aged structures, the information of the structure is often lost after the completion of construction, and there is a great difficulty in predicting the durability life of the structure due to the lack of information on concrete formulations. In this study, the durability of concrete specimens was evaluated by various field and indoor test methods based on the core specimens collected from the field, and the durability life of the concrete structures was predicted by using the FEM analysis technique.As a result, the neutralization rate coefficient was $5.38E-6(cm^2/day)$ and the rate of progress was low. And the possibility of complex deterioration due to carbonation and salting was found to be very low.

  • https://doi.org/10.15683/kosdi.2017.09.30.332 인용 PDF KSCI

Numerical simulation approach for structural capacity of corroded reinforced concrete bridge

  • Zhou, Xuhong;Tu, Xi;Chen, Airong;Wang, Yuqian
    • Advances in concrete construction
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    • v.7 no.1
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    • pp.11-22
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    • 2019

  • A comprehensive assessing approach for durability of reinforced concrete structures dealing with the corrosion process of rebar subjected to the attack of aggressive agent from environment was proposed in this paper. Corrosion of rebar was suggested in the form of combination of global corrosion and pitting. Firstly, for the purposed of considering the influence of rebar's radius, a type of Plane Corrosion Model (PCM) based on uniform corrosion of rebar was introduced. By means of FE simulation approach, global corrosion process of rebar regarding PCM and LCM (Linear Corrosion Model) was regressed and compared according to the data from Laboratoire $Mat{\acute{e}}riaux$ et $Durabilit{\acute{e}}$ des Constructions (LMDC). Secondly, pitting factor model of rebar in general descend law with corrosion degree was introduced in terms of existing experimental data. Finally, with the comprehensive numerical simulation, the durability of an existing arch bridge was studied in depth in deterministic way, including diffusion process and sectional strength of typical cross section of arch, crossbeam and deck slab. Evolution of structural capacity considering life-cycle rehabilitation strategy indicated the degradation law of durability of reinforced arch bridges.

  • https://doi.org/10.12989/acc.2019.7.1.011 인용 KSCI

Evaluation of Applicability of penetrating-type Nano-Coat for Preventing Deterioration of Concrete (침투형 Nano-Coat를 이용한 콘크리트 열화 방지 적용성 평가)

  • Lee, Jun Hee;Kim, Jo Soon;Sim, Yang Mo;Lee, Seung Woo
    • International Journal of Highway Engineering
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    • v.19 no.2
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    • pp.7-15
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    • 2017

  • PURPOSES : Infiltration of moisture, polluted material, and deicer into concrete, accompanied by freeze and thaw can cause significant deterioration of concrete pavement. In order to protect concrete from deterioration, it is necessary to prevent the infiltration of these concrete external materials. The moisture-repellent agent, which is a surface treatment and maintenance material added to concrete structures to render them water resistant, has advantages such as prevention of water infiltration and security against air permeation. Nano-coat, which is referred to as silicon hydride, is typically used as a moisture-repellent agent. Therefore, in this study, an attempt is made to use penetration-type Nano-coat as an alternative in order to evaluate its applicability through environmental resistance tests. METHODS : This study aimed to evaluate the applicability of penetration-type Nano-coat, which can provide water repellency to concrete, in concrete pavements, through various environmental resistance tests such as freezing and thawing resistance, chloride ion penetration resistance, and surface scaling resistance tests. The applicability of penetration-type Nano-coat was demonstrated based on the specification of KS F 2711, KS F 2456, and ASTM C 672. RESULTS :In the case of penetration-type Nano-coat applied on sound concrete, an increase in concrete durability was demonstrated by the negligible chloride ion penetrability and the absence of scaling, as revealed by visual observation of the surface, after 50 cycles of scaling resistance test. In addition, test result of the application of penetration-type Nano-coat on deteriorated concrete established that concrete surface pretreated by grinding provided improved durability than non-treated concrete. CONCLUSIONS :This study indicates that penetration-type Nano-coat is applicable as an effective alternative, to increase the durability of concrete structures. In addition, it was known that pretreatment of deteriorated concrete surface, such as grinding, is required to improve the long-term performance of concrete pavement.

  • https://doi.org/10.7855/IJHE.2017.19.2.007 인용 PDF KSCI