Evaluation of the AgNO3 solution spray method for measurement of chloride penetration into hardened cementitious matrix materials

63Marine durability of 30-year-old concrete specimens made with ordinary portland cement (OPC), high early strength portland cement (HES), moderate heat portland cement (MH), slag cement of type B (SCB), and alumina cement (AL) was investigated. Other parameters include sulfate content in cement, mixing water, and different exposure zones. Compressive strength, chloride ingress, corrosion of steel bars in concrete, microstructure, mineralogy of concrete, and steel-matrix and aggregate-matrix interfaces were investigated. Chloride ingress in concrete was sequenced as OPC, HES, MH>SCB>AL. However, for AL mixed with tap water, corrosion on steel bars in concrete was higher. For SCB and AL, the pore volume at the outer region of the specimens is reduced due to the ingress of chloride and other ions from seawater. Marine Durability of 30-Year Old Concrete Made with Different CementsTarek Uddin Mohammed 1 , Hidenori Hamada 2 and Toru Yamaji 3 Abstract 1. Introduction

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“…The passivity grades are defined as 0, 1, 2, 3, 4, and 5. Lower grade of passivity means higher corrosion activity (Otsuki et al 1992).…”

Section: Casementioning

confidence: 99%

“…At the deeper cover depths less current density is observed. The passivity grades of the steel bars were evaluated based on the procedure developed by Otsuki et al (1992) and are listed in Table 7 Anodic current density at 0.2V and 0.6V. Vol.…”

Section: Electrochemical Evaluation Of Corrosionmentioning

confidence: 99%

Marine Durability of 30-Year Old Concrete Made with Different Cements

Mohammed

Hamada

Yamaji

2003

ACT

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“…Similar process was done after 60 and 90 days salt ponding of other specimens successively. This process is known as colorimetric process ( [10], [11]) which is less time consuming and simpler than other methods. …”

Section: Determination Of Depth Of Salt Penetrationmentioning

confidence: 99%

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

Mamun¹,

Islam²

2017

Journal of Construction Engineering and Project Management

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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.

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“…6 Concept of the passivity grade. 10) using the grinder and polisher until the thickness of the test piece became 0.5mm. Then the test piece was fixed at the center of acrylic cylinder cell.…”

Section: Chloride Diffusion Coefficient In Cement Pastementioning

confidence: 99%

“…The method described by Otsuki et al 10) as shown in Fig. 6 which measured the polarization curve was used.…”

Section: Grade Of Passivitymentioning

confidence: 99%

Corrosion of Steel Bars in Autoclaved Concrete Pile Containing γ-2CaO·SiO2 with an Accelerated Carbonation Curing Submerged in the Real Marine Environment

Saphouvong

Saito

Otsuki

et al. 2012

J. Soc. Mat. Sci., Japan

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This paper presents a set of the investigation of corrosion of steel bars in autoclaved concrete pile containing γ -2CaO ·SiO2 (γ -C2S) with carbonation curing. OPC, γ -C2S, and fine silica powder were used as the binders; the replacement ratio of OPC by γ -C2S was 0%, 40%, and 80% by mass. Autoclaved concrete pile after carbonation was submerged in real marine environment at Kurihama Bay for two years. After immersion, visual observation of steel bars was conducted to confirm the corrosion state of steel inside the concrete pile. Furthermore, to evaluate the corrosion of steel bars -weight loss, corrosion current density, and anodic polarization curve were measured ; various corrosion substances also were measured to evaluate the permeability of corrosion factors. In addition, cement past sample with same mixed proportion and curing condition was made for explaining the permeable characteristics of corrosion substances. As the results, the steel bars in the 80% γ -C2S replacement ratio did not corrode while steel bars in the other mixed proportions had corroded. The weight loss of steel bar in the 80% γ -C2S replacement ratio after carbonation reduced by 39% and corrosion current density reduced more than 95% compared with the 0% γ -C2S replacement ratio. Furthermore, the corrosion substances in concrete pile -carbonation depth, total chloride ion content, and oxygen diffusion rate, reduced significantly at the 80% replacement ratio of γ -C2S. Based on the overall results of this study, we suggest that, when using γ -C2S with an autoclave curing, accelerated carbonation curing is able to do to densify the concrete surface preventing the steel from corrosion for the long-term exposure.Key words : γ-2CaO ·SiO2

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Evaluation of the AgNO3 solution spray method for measurement of chloride penetration into hardened cementitious matrix materials

Cited by 115 publications

References 1 publication

Marine Durability of 30-Year Old Concrete Made with Different Cements

Marine Durability of 30-Year Old Concrete Made with Different Cements

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

Corrosion of Steel Bars in Autoclaved Concrete Pile Containing γ-2CaO·SiO2 with an Accelerated Carbonation Curing Submerged in the Real Marine Environment

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