Influence of Bleeding on Minute Properties and Steel Corrosion in Concrete

Baccay, Melito A.; Nishida, Takahiro; Otsuki, Nobuaki; Hamamoto, Junpei; Chin, K.J.

doi:10.3151/jact.2.187

Cited by 7 publications

(5 citation statements)

References 9 publications

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“…The bleeding affects the integrity of the reinforced concrete owing to the larger gaps or voids formed at the steel and concrete interface. According to past investigation, the bleeding of fresh concrete qualitatively diminishes the durability of horizontal steel bars embedded in concrete structures (Mohammed et al, 2002;Baccay et al, 2004).…”

Section: Effects Of Bleeding On the Corrosion Of Horizontal Steel Barmentioning

confidence: 99%

Effects of Bleeding on the Corrosion of Horizontal Steel Bars in Reinforced Concrete Column Specimens

Sandra¹,

Kawaai²,

Ujike³

et al. 2019

IJTech

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The durability of reinforced concrete has proven to be predominantly influenced by its resistance against the ingress of harmful substances such as chloride ions, carbon dioxide and moisture. The corrosion of steel bars which occurs especially in marine environments is likely to be severe, depending on the availability of oxygen and the moisture consumed by cathodic reactions. This study aims to investigate the effects of bleeding on the corrosion of horizontal steel bars placed in reinforced concrete column specimens. The issue was examined through electro-chemical tests, including half-cell potential, polarization resistance and corrosion current density, conducted using specimens in which corrosion was induced via dry and wet (NaCl 10%) cycles. The presence or absence of copper slag fine aggregate and fly ash replacement was employed as an experimental parameter. The results suggest that the corrosion of horizontal steel bars in the upper part of the column concrete specimens was adversely affected, even in the case of OPC specimens with relatively lower bleeding water. This was attributed to lower resistance against the ingress of corrosive substances, especially in such locations. In the case of fly ash mixtures, resistance to corrosion was significantly improved owing to lower oxygen permeability of less than 1.0×10-11 mol/cm²/sec, measured via the cathodic polarization technique. The replacement of fly ash is effective in facilitating more uniform quality in the column specimens due to a lower level of bleeding water and higher resistance to segregation and pozzolanic reactions.

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Section: Effects Of Bleeding On the Corrosion Of Horizontal Steel Barmentioning

confidence: 99%

Effects of Bleeding on the Corrosion of Horizontal Steel Bars in Reinforced Concrete Column Specimens

Sandra¹,

Kawaai²,

Ujike³

et al. 2019

IJTech

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“…Also, the presence of gaps/vulnerable zone at the steel-concrete interface causes the complete loss of passivity with the presence of chloride. A part of concrete affected by bleeding exhibited weaker strength, higher permeability, lower concrete resistance, and higher oxygen permeability [6,7].…”

Section: Fig2 Microcell and Macrocell Corrosionmentioning

confidence: 99%

“…The macrocell current flowing can be calculated based on Eq. (1), the readings obtained from the ammeter and dividing them with the surface area of the steel [7]. where Imacro: macrocell corrosion current density (A/cm 2 ); Ii: current flowing of steel element (A); and Si: surface area of steel element i (cm 2 )…”

Section: Macrocell (Corrosion Rate)mentioning

confidence: 99%

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Corrosion Current Density of Macrocell of Horizontal Steel Bars in Reinforced Concrete Column Specimen

Sandra¹

2019

GEOMATE

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Chloride-induced corrosion of steel bar in concrete is one of the main problems affecting the durability of reinforced concrete (RC) structures. Expansive products are formed due to corrosion at the interface between concrete and steel bar. In this study, the differences in the magnitude of the macrocell corrosion current density in RC column specimens cast using copper slag fine aggregate and fly ash replacement were examined. This study aimed at investigating corrosion formation with respect to macrocell corrosion current density. The experimental study was carried out through dry and wet (NaCl 10%) cycles for specimens with different cover depths, which was investigated by electrochemical measurements. The result shows that the largest macrocell corrosion current density was measured in the steel bars located at the upper part of reinforced column specimens for each case of the specimens with a cover depth of 30 mm. This could be partly attributed to the loss of the integrity of the steel and concrete interface which is examined based on the oxygen permeability in the upper and lower sides of segmented steel bars. The variation of oxygen permeability contributes to the macrocell corrosion formation especially in the steel bars affected by bleeding water. Besides the integrity between steel bars and concrete cover, the quality of concrete cover and variations in chloride ion concentrations are significant factors contributing to the macrocell corrosion formation.

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“…Baccay and et al (2004). Viscosity modifying admixtures and cellulose fibers as beneficial options has been explored by various scholars and results were reported.…”

Section: Introductionmentioning

confidence: 99%

Concrete Lining Pathology for Bleeding: Penstock and Surge Tank of Upper Gotvand Dam

Zabihollahzadeh¹,

Ghorbani²

2015

IJET

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Abstract-Several problems involved with concrete excess bleeding, such as durability and strength mitigation, unsightly surface, delayed finishing or postponed mold translocation. The purpose of study is to detectmajor cause for excess bleeding in Gotvand affiliated projects.Thus, interaction among different ingredientswas surveyed viaslurry mixes. That way the most consistent components and subsequently approperiate mixes were emerged . Besides that some alternative treatments were proposed as well.Then sort of physical model was devised to evaluate bleeding rate and capacity for each alternative mixes.Chemically inconsistent behaviorof components, poor fine content, nonuniform cement manufacturing have beeen recognized as major motives. Bringing stone powder back to sand production cycle was concluded as an effective as well as most economic treatment option.Concrete placement into segment through mere one access point at each elevation of formwork, thus unfavorable concrete displacement using formwork vibrators was identified as the most harmful executive cause as well.

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Influence of Bleeding on Minute Properties and Steel Corrosion in Concrete

Cited by 7 publications

References 9 publications

Effects of Bleeding on the Corrosion of Horizontal Steel Bars in Reinforced Concrete Column Specimens

Effects of Bleeding on the Corrosion of Horizontal Steel Bars in Reinforced Concrete Column Specimens

Corrosion Current Density of Macrocell of Horizontal Steel Bars in Reinforced Concrete Column Specimen

Concrete Lining Pathology for Bleeding: Penstock and Surge Tank of Upper Gotvand Dam

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