Engineering Commons^™

Evaluation Of Residual Flexural Behavior Of Corroded Fiber-Reinforced Super Workable Concrete Beams, Jingjie Wei, Nima Farzadnia, Alfred Addai-Nimoh, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Study Investigates the Effect of Macro Synthetic Fiber (MSF) Volume and Crack Widths on Corrosion of the Reinforcing Bars and Residual Flexural Behavior of Fiber-Reinforced Super-Workable Concrete (FR-SWC) Beams Exposed to Accelerated Corrosion. FR-SWC Beams Prepared with 0, 0.33%, and 0.66% MSF Were Pre-Cracked at 0.2-, 0.4-, and 0.75-Mm Widths Before Corrosion Testing. the Controlled Crack Width Was Initiated in One Set of Beams that Were Then Unloaded. the Crack Width Was Maintained for Another Set of Beams during Corrosion Testing by Inserting a Shim. Test Results Showed that the Use of 0.33% and 0.66% MSF Reduced Crack Development …

Coating Condition Detection And Assessment On The Steel Girder Of A Bridge Through Hyperspectral Imaging, Pengfei Ma, Jiaoli Li, Ying Zhuo, Pu Jiao, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The organic coating of bridge steel girders is subjected to physical scratches, corrosion, and aging in natural weathering. The breakdown of the coating may cause serviceability and safety problems if left unnoticed. Conventional coating inspection is time-consuming and lacks information about the coating's chemical integrity. A hyperspectral imaging method is proposed to detect the condition of steel coatings based on coating-responsive features in reflectance spectra. A field test was conducted on the real-world bridge, which shows obvious signs of degradation. The hyperspectral signature enables an assessment of the coating's health and defect severity. The results indicated that the coating scratch …

Wavelet Power And Shannon Entropy Applied To Acoustic Emission Signals For Corrosion Detection And Evaluation Of Reinforced Concrete, Jinrui Zhang, Ziye Kang, Dongshuai Hou, Biqin Dong, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Acoustic emission (AE) signals detected from corrosion test on a steel reinforced concrete beam subjected to the coupling effects of corrosive wet-dry cycles and static load are analyzed by power spectral density, wavelet transform, and Shannon entropy. The degradation process of the corroded reinforced concrete beam can be divided into four stages on the basis of the accumulated event number (AEN). Due to the difference of material properties, steel reinforcement and concrete matrix have distinguished AE features. The time-frequency characteristics of AE signals can reflect the microstructural degradation mechanism of steel corrosion and concrete cracking. The corrosion evaluation entails investigating …

Bridge Resilience Assessment With Inspire Data, Iris Tien, Yijian Zhang

Project RR-1

This project proposed a methodology to assess the impact of corrosion on the performance of bridges. The combined analytical and numerical modeling of shear-critical and lap-spliced columns is detailed, and outcomes are verified with previous experimental test data. The impact of corrosion on risk is assessed through conducting fragility analyses. Results quantify the increase in failure probabilities of these structures, measured by increasing probabilities of exceeding defined damage states, with increasing levels of corrosion. Corrosion is found to have a larger impact on increasing probabilities of exceeding more severe damage states. Twenty percent mass loss of reinforcement increases the probability …

Spatial Delineation Of Corrosion Zones For Metal Culverts Based On Coastal Louisiana Soil Characteristics, Sanjay Tewari, Francis Manning

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Corrosion of metal pipes used as culverts is a problem that affect many agencies directly involved in designing and maintaining these culverts. The corrosive environment of soil types found in a region could vary in a significant way (mildly corrosive to extremely corrosive) based on soil characteristics. Environmental conditions such as high water table, acidity and presence of various salts could make a soil corrosive to metal pipes. In this article, authors have applied a methodology of processing readily available soil data such as spatial distribution of soil types and soil characteristics (e.g. pH and conductivity) in delineating spatial corrosion …

Identifying Corrosion Zones In Coastal Regions For Metal Pipes -- A Gis Approach, Sanjay Tewari, Francis Manning

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Transportation agencies often allow metal pipes as an option for cross drains under/along roads and highways. Metal culverts can corrode over time at various rates based on their environmental conditions (e.g., corrosive nature of coastal soils, high water table and saltwater intrusion). This paper focuses on applying readily available soil data such as spatial distribution of soil types and soil characteristics (e.g., pH and conductivity) towards creating a geospatial information system (GIS) based approach to identifying corrosion zones in the coastal regions. A combination of data, obtained from field surveys provided by the Louisiana Transportation Research Center and Web Soil …

Corrosion Map For Metal Pipes In Coastal Louisiana, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Transportation agencies often allow metal pipes as an option for cross drains under/along roads and highways. Metal culverts can corrode over time at various rates based on their environmental conditions (e.g., corrosive nature of coastal soils, high water table, and saltwater intrusion).

This project was focused on applying available soil data, such as spatial distribution of soil types and soil characteristics (e.g., pH and conductivity), towards creating a Geographic Information System (GIS) based map to identify corrosion zones in coastal Louisiana. The effect of the soil characteristics (pH and conductivity) was incorporated in to the published corrosion models for calculating …

Weak Magnetic Field Accelerates Chromate Removal By Zero-Valent Iron, Pian Feng, Xiaohong Guan, Yuankui Sun, Wonyong Choi, Hejie Qin, Jianmin Wang, Junlian Qiao, Lina Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Weak magnetic field (WMF) was employed to improve the removal of Cr(VI) by zero-valent iron (ZVI) for the first time. The removal rate of Cr(VI) was elevated by a factor of 1.12-5.89 due to the application of a WMF, and the WMF-induced improvement was more remarkable at higher Cr(VI) concentration and higher pH. Fe2+ was not detected until Cr(VI) was exhausted, and there was a positive correlation between the WMF-induced promotion factor of Cr(VI) removal rate and that of Fe²⁺ release rate in the absence of Cr(VI) at pH 4.0-5.5. These phenomena imply that ZVI corrosion with Fe^{2+ …}