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Accelerated corrosion of steel in dry-cast reinforced concrete pipes after initiation
Title
Accelerated corrosion of steel in dry-cast reinforced concrete pipes after initiation.
Creator
Weber, Brian W., Presuel-Moreno, Francisco, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Instrumented dry-cast reinforced concrete pipe (DC-RCP) specimens in which corrosion of the reinforcing steel had initiated were selected to accelerate the corrosion. Type C and type F DC-RCP were used. An anodic current density of various magnitudes (0.5 μA/cm2, 1 μA/cm2 and 2.5 μA/cm2) was applied during the corrosion propagation stage. The specimens were placed in high humidity and selected specimens were later covered with wet sand. Selected specimens were terminated for visual...
Show moreInstrumented dry-cast reinforced concrete pipe (DC-RCP) specimens in which corrosion of the reinforcing steel had initiated were selected to accelerate the corrosion. Type C and type F DC-RCP were used. An anodic current density of various magnitudes (0.5 μA/cm2, 1 μA/cm2 and 2.5 μA/cm2) was applied during the corrosion propagation stage. The specimens were placed in high humidity and selected specimens were later covered with wet sand. Selected specimens were terminated for visual examination and gravimetric analysis. Typically, the reinforcement potentials during the accelerated corrosion period were more negative for F specimens compared to C specimens. The C specimens experienced ~2× more corrosion than the F specimens. The accumulated corrosion products did not cause cracks. A method was developed that allows for modest corrosion acceleration during the corrosion propagation stage of DC-RCP.
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Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004233, http://purl.flvc.org/fau/fd/FA00004233
Subject Headings
Concrete -- Deterioration, Corrosion and anti corrosives, Pipelines -- Design and construction, Tubular steel structures -- Deterioration
Format
Document (PDF)
Initiation and propagation of corrosion in dry-cast reinforced concrete ring specimens
Title
Initiation and propagation of corrosion in dry-cast reinforced concrete ring specimens.
Creator
Seo, Bongjoon, Presuel-Moreno, Francisco, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The corrosion propagation stage of D-CRP (types F and C) was tested under immersion in water, high humidity, and covered with wet sand. The half-cell potential, linear polarization test, and electrochemical impedance spectroscopy measurements were performed. Selected specimens were terminated after 300 days of exposure and visually inspected. Based on corrosion potential measurements obtained during the corrosion propagation observation, and calculated corrosion rate based on LPR measurements...
Show moreThe corrosion propagation stage of D-CRP (types F and C) was tested under immersion in water, high humidity, and covered with wet sand. The half-cell potential, linear polarization test, and electrochemical impedance spectroscopy measurements were performed. Selected specimens were terminated after 300 days of exposure and visually inspected. Based on corrosion potential measurements obtained during the corrosion propagation observation, and calculated corrosion rate based on LPR measurements: all specimens were actively corroding. Additionally, EIS-Rc values were calculated for FS, CS and CH specimens. The Rc_EIS were generally greater than Rc_LPR values. EIS spectra for CI and FI specimens usually included mass transport limitations, as these specimens were immersed. Both type of specimens immersed in water (FI and CI), appeared to have higher corrosion rate based on LPR-Rc. However, upon autopsy it was revealed that a more modest amount of corrosion occurred on the reinforcing steel of FI and CI terminated specimens.
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Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004226, http://purl.flvc.org/fau/fd/FA00004226
Subject Headings
Concrete -- Deterioration, Concrete construction, Corrosion and anti corrosives, Reinforced concrete -- Chemical resistance, Tubular steel structures -- Deterioration
Format
Document (PDF)
Initiation and propagation of corrosion in dry-cast reinforced concrete pipes
Title
Initiation and propagation of corrosion in dry-cast reinforced concrete pipes.
Creator
Balasubramanian, Hariharan, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This study investigates corrosion initiation and propagation in instrumented specimens obtained from segments of dry-cast reinforced concrete pipes. Potential, LPR and EIS measurements were carried out. During the propagation stage in different exposures, reinforcement eventually reached negative potentials values, which suggest mass transfer limitations. So far these specimens show no visual signs of corrosion such as cracks or corrosion products with one exception; where corrosion products...
Show moreThis study investigates corrosion initiation and propagation in instrumented specimens obtained from segments of dry-cast reinforced concrete pipes. Potential, LPR and EIS measurements were carried out. During the propagation stage in different exposures, reinforcement eventually reached negative potentials values, which suggest mass transfer limitations. So far these specimens show no visual signs of corrosion such as cracks or corrosion products with one exception; where corrosion products have reached the surface. Moreover, the apparent corrosion rate values obtained suggest high corrosion rate. No crack appearance so far, could be explained by the high porosity of the specimens; the corrosion products are filling these pores. It is speculated that although, there might be mass transfer limitations present, the current demanded by the anode is being balanced by a larger cathode area due to macrocell effects, since the high moisture conditions likely reduced the concrete resistivity and increased the throwing power.
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Date Issued
2013
PURL
http://purl.flvc.org/fcla/dt/3362341
Subject Headings
Concrete, Deterioration, Tubular steel structures, Deterioration, Pipelines, Design and construction, Concrete construction, Corrosion and anti-corrosives
Format
Document (PDF)