Server maintenance is scheduled for Saturday, December 21st between 6am-10am CST.
During that time, parts of our website will be affected until maintenance is completed. Thank you for your patience.
Use GIVING24 at checkout to save 20% on eCourses and books (some exclusions apply)!
Chloride-induced corrosion of steel reinforcement in concrete structures usually experiences two stages: pitting corrosion initiation and propagation.1-2 Initiation of pitting corrosion occurs as the chloride content on the surface of a steel bar exceeds a critical value (or chloride threshold) and breaks down the passive film locally.3-4 Depending on environmental factors at the steel-concrete interface, such as temperature, moisture, and availability of oxygen, pitting corrosion initiation is not stable in the very beginning and some corrosion pits may continue to develop and become stable, while others cease.
This study aims to statistically analyze the distribution characteristics of localized corrosion along the length of corroded steel bars with spectral analysis techniques. Steel bars were embedded in a concrete prism and subjected to accelerated corrosion to levels ranging from 5.0 wt.% to 30.0 wt.% mass loss. After the corrosion test, the corroded steel bars were taken out of the concrete and cleaned with a sand blaster, and then scanned with a 3D laser scanner. The scanned point clouds were processed with an image processing software to determine the residual cross-sectional area distribution. Empirical mode decomposition (EMD) was performed by considering the area distribution of the steel bars as a nonlinear and non-stationary time series and the length as time. The intrinsic mode functions (IMFs) extracted from the EMD reveal the characteristics of pitting corrosion of various sizes, and the magnitude of the IMF is related to the cross-sectional area of corrosion pits. To extract the characteristic length of pitting corrosion, the fast Fourier transform (FFT) was performed on each IMF. Results show that the EMD-FFT successfully extracts the spatial distribution characteristics of corroded steel bars including surface irregularity, deformation (ribs and lugs), small corrosion pits and big corrosion pits. Presence of pitting corrosion changes the characteristic length of surface irregularity and rib spacing compared to a non-corroded bar.
Carbon dioxide (CO2) saturated brines containing high levels of calcium are commonly encountered across the energy sector: from hydrocarbon recovery to the harvesting of geothermal energy and re-deposition of CO2 for permanent storage. These brines originate in deep underground reservoirs at elevated pressures and temperatures. Despite susceptibility to corrosive attack under these conditions, carbon steels are the preferred choice of pipeline materials for such processes, attributable to their low cost, availability and ease of manufacture.
We are unable to complete this action. Please try again at a later time.
If this error continues to occur, please contact AMPP Customer Support for assistance.
Error Message:
Please login to use Standards Credits*
* AMPP Members receive Standards Credits in order to redeem eligible Standards and Reports in the Store
You are not a Member.
AMPP Members enjoy many benefits, including Standards Credits which can be used to redeem eligible Standards and Reports in the Store.
You can visit the Membership Page to learn about the benefits of membership.
You have previously purchased this item.
Go to Downloadable Products in your AMPP Store profile to find this item.
You do not have sufficient Standards Credits to claim this item.
Click on 'ADD TO CART' to purchase this item.
Your Standards Credit(s)
1
Remaining Credits
0
Please review your transaction.
Click on 'REDEEM' to use your Standards Credits to claim this item.
You have successfully redeemed:
Go to Downloadable Products in your AMPP Store Profile to find and download this item.
TSA is mainly used to protect offshore steel structures, including atmospheric, splash and immersed zones. During installation or in service, the coating is likely to be damaged due to erosion, wear, scratch etc. TSA coatings protect by acting as a barrier and offering cathodic protection even if the substrate is exposed to seawater.
When two long-time operators of natural gas storage wells in southwestern Ontario merged, it was an opportune time for the combined company to evaluate the effectiveness and impact of cathodic protection (CP). Staff from both legacy operators expressed general satisfaction with the longevity of their storage wells, typically 30+ years, but they had relied on two different approaches to corrosion control: one had isolated wells from flowlines and operated without CP, while the second had resistively bonded wells to cathodically protected flowlines. For the second operator, typical well currents were in the range of ~3 A.