• Title, Summary, Keyword: chloride penetration depth

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Chloride Penetration Analysis of Concrete Structures with Chloride Concentration (염분 농도에 따른 콘크리트 구조물의 염분침투 해석)

  • Yang, Joo-Kyoung
    • Journal of the Korea Computer Industry Society
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    • v.9 no.3
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    • pp.137-142
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    • 2008
  • The major influence factor on chloride penetration into concrete structures is chloride ion concentration. In this study, chloride penetration analyses with chloride ion concentration were carried out by the developed program. Also, the service life of concrete structures was predicted. The penetration depth was 32mm in case that chloride ion concentration wad 600ppm. It was shown that the service life of concrete structures with 40mm cover depth was 167 years even though they had been exposed at chloride ion concentration 600ppm during 100 years.

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Strength and chloride penetration of Portland cement mortar containing palm oil fuel ash and ground river sand

  • Rukzon, Sumrerng;Chindaprasirt, Prinya
    • Computers and Concrete
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    • v.6 no.5
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    • pp.391-401
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    • 2009
  • This paper presents a study of the strength and chloride penetration of blended Portland cement mortar containing ground palm oil fuel ash (POA) and ground river sand (GS). Ordinary Portland cement (OPC) was partially replaced with POA and GS. Compressive strength, rapid chloride penetration test (RCPT) and chloride penetration depth of mortars were determined. The GS only asserted the packing effect and its incorporation reduced the strength and the resistance to chloride penetration of mortar. The POA asserted both packing and pozzolanic effects. The use of the blend of equal portion of POA and GS also produced high strength mortars, save cost and excellent resistance to chloride penetration owing to the synergic effect of the blend of POA and GS. For chloride depth, the mathematical model correlates well with the experimental results. The computer graphics of chloride depth of the ternary blended mortars are also constructed and can be used to aid the understanding and the proportioning of the blended system.

Experimental Investigation of Chloride Ion Penetration and Reinforcement Corrosion in Reinforced Concrete Member

  • Al Mamun, Md. Abdullah;Islam, Md. Shafiqul
    • Journal of Construction Engineering and Project Management
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    • v.7 no.1
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    • pp.26-29
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    • 2017
  • This paper represents the experimental investigation of chloride penetration into plain concretes and reinforced concretes. The main objective of this work is to study the main influencing parameters affecting corrosion of steel in concrete. Plain cement concrete and reinforced cement concrete with different water-cement ratios and different cover depth were subjected to ponding test. Ponding of specimens were done for different periods into 10% NaCl solution. Depth of penetration of chloride solution into specimens was measured after ponding. Specimens were crushed and reinforcements were washed using $HNO_3$ solution and weight loss due to corrosion was calculated accordingly. There was a linear relationship between depth of penetration and water-cement ratio. It was also observed that, corrosion of reinforcing steel increases with chloride ponding period and with water-cement ratio. Corrosion of steel in concrete can be minimized by providing good quality concrete and sufficient concrete cover over the reinforcing bars. Water-cement ratio has to be low enough to slow down the penetration of chloride salts into concrete.

Examination on Required Cover Depth to Prevent Reinforcement Corrosion Risk in Concrete

  • Yoon, In-Seok
    • Corrosion Science and Technology
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    • v.11 no.5
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    • pp.157-164
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    • 2012
  • In first experiment series, this paper is devoted for examining progress of reinforcement corrosion due to carbonation in concrete and to quantify uncarbonation depth to protect reinforcement from corroding. The tolerance of cover depth should be considered in order to prevent carbonation-induced corrosion. From the relationship between the weight loss of reinforcement and corrosion current density for a given time, therefore, the tolerance of cover depth to prevent carbonation-induced corrosion is computed. It is observed that corrosion occurs when the distance between carbonation front and reinforcement surface (uncarbonated depth) is smaller than 5 mm.As a secondary purpose of this study, it is investigated to examine the interaction between carbonation and chloride penetration and their effects on concrete. This was examined experimentally under various boundary conditions. For concrete under the double condition, the risk of deterioration due to carbonation was not severe. However, it was found that the carbonation of concrete could significantly accelerate chloride penetration. As a result, chloride penetration in combination with carbonation is a serious cause of deterioration of concrete.

An Experimental Study on the Salt Damage Resistance of High Durable Concrete (고내구성콘크리트의 염해저항성에 관한 실험적 연구)

  • Yoon, Jai-Hwan;Jaung, Jae-Dong
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.3
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    • pp.73-81
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    • 2003
  • In this paper, salt damage resistance of high durable concrete was tested. High durable concrete was made by using low water cement ratio, chemical admixture called super-durable admixture and mineral admixtures such as fly-ash, ground granulated blast-furnace slag, silica fume. Two kinds of salt damage resistance test were carried out. One method is chloride ion penetration test(ASTM C1202), and the other one is depth of chloride penetration test in saline solution. Test results were as followers: 1) The depth of chloride ion penetration increased exponentially as water cement ratio was increased and time passed. 2) Super-durable admixture had little effect on the improvement of salt damage resistance of concrete. 3) Silica fume and ground granulated blast-furnace slag were effective on salt damage resistance because of pozzolanic reaction, but fly-ash had a little effect.

Analytical study of the influence of crack width and depth on the penetration of chloride ion and the carbonation (균열 폭 및 깊이가 염소이온 침투 및 탄산화에 미치는 영향에 대한 해석적 연구)

  • Kim, Chin-Yong;Kim, Jin-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.594-597
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    • 2006
  • Chloride ion penetration and carbonation are the most important factors in the durability problems of reinforced concrete structures. Most of the existing studies on those subjects are focused on the no-crack concrete, though the existence of crack may strongly affect the chloride ion penetration and carbonation. To evaluate the influence of crack on the chloride ion penetration and carbonation and to assess the service life of reinforced concrete more accurately, finite volume analyses (FVA) were performed based on the FV mesh containing the ideal crack whose width is uniform along the depth. Analytical results show that the influence of crack width and depth is much more pronounced for the chloride ion penetration than for the carbonation.

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New experiment recipe for chloride penetration in concrete under water pressure

  • Yoon, In-Seok;Nam, Jin-Won
    • Computers and Concrete
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    • v.17 no.2
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    • pp.189-199
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    • 2016
  • Chloride penetration is considered as a most crucial factor for the determination of the service life of concrete. A lot of experimental tools for the chloride penetration into concrete have been developed, however, the mechanism was based on only diffusion, although permeability is also main driving forces for the chloride penetration. Permeation reacts on submerged concrete impacting for short to long term durability while capillary suction occurs on only dried concrete for very early time. Furthermore, hydrostatic pressure increases in proportional to measured depth from the surface of water because of the increasing weight of water exerting downward force from above. It is thought, therefore, that the water pressure has a great influence on the chloride penetration and thereby on the service life of marine concrete. In this study, new experiment is designed to examine the effect of water pressure on chloride penetration in concrete quantitatively. As an experiment result, pressure leaded a quick chlorides penetration by a certain depth, while diffusion induced chlorides to penetrate inward slowly. Therefore, it was concluded that chloride should penetrates significantly by water pressure and the phenomena should be accelerated for concrete exposed to deep sea. The research is expected as a framework to define the service life of submerged concrete with water pressure and compute water permeability coefficient of cementitious materials.

The Effect of Mineral Admixtures' Type on the Chloride Penetration Resistance of Concrete (콘크리트의 염화물 침투저항성에 미치는 무기질 혼화재 종류의 영향)

  • Kim, Young-Jin;Kim, Dong-Seok;Yu, Jae-Kang
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.802-805
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    • 2004
  • This study was performed to investigate the effect of mineral admixture' type and replacement ratios on the chloride penetration resistance of concrete which was immersed in the artificial chloride solution. The chloride penetration resistance was evaluated by penetration depth and chloride diffusion coefficient. As a result, all of the mineral admixtures were effective on the chloride penetration resistance of concrete compared to ordinary portland cement only.

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Effect of Micro-Cracks on Chloride Ions Penetration of Concrete II: Examination of Critical Crack Width (미세균열이 콘크리트의 염소이온 침투에 미치는영향 II: 임계 균열폭의 고찰)

  • Yoon, In-Seok
    • Journal of the Korea Concrete Institute
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    • v.19 no.6
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    • pp.707-715
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    • 2007
  • The vulnerability of concrete to its environment is significantly dependent on the fact that concrete is a porous material. For well-consolidated and well-cured concrete, its service life is a very long and an entrance of aggressive substance might be only pores. However, for cracked concrete, cracks should be preferential channel for the penetration of aggressive substance such as chloride ions. The effect of crack on chloride penetration depends on its size for example, crack width and crack depth. The purpose of this study is examining the effect of crack width and crack depth on chloride penetration. In order to visualize chloride penetration via cracks, RCM (rapid chloride migration) testing is accomplished. Crack width is examined using an optical microscope and CMOD value is used to estimate average crack width. From the examination on the trend of chloride diffusion coefficients of concrete specimens with various crack widths, a critical crack width and a critical crack depth are found out.

Analysis of Chloride ion Penetration of Marine Concrete Structure (해양 콘크리트 구조물의 염소이온 침투해석)

  • 한상훈;박우선;김동현
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.15 no.2
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    • pp.71-79
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    • 2003
  • The estimation functions were proposed for calculating diffusion coefficient, chloride binding, and evaporable water. The program estimating chloride ion penetration was developed on the basis of these functions and the effects of humidity, curing temperature, water-cement ratio, and $C_3$A on chloride penetration were analyzed. The relative humidity increases the depth of chloride ion penetration and the trend becomes greater with aging. On the contrary, the influence of curing temperature on chloride ion penetration decreases with aging. By the way, the rise of $C_3$A in cement increases total chloride concentration on the surface as the bound chloride concentration increases but it decreases total chloride concentration on the inner part as the diffusion velocity of free chloride decreases. The fall of water-cement ratio decreases the chloride penetration depth rapidly. Therefore, the reduction of water-cement ratio may be the most effective method for reducing of the steel corrosion by chloride penetration.