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Full-Text Articles in Engineering
A Computational Investigation Of The Interstitial Oxidation Thermodynamics Of A Mo-Nb-Ta-W High Entropy Alloy Beyond The Dilute Regime, Adib J. Samin
A Computational Investigation Of The Interstitial Oxidation Thermodynamics Of A Mo-Nb-Ta-W High Entropy Alloy Beyond The Dilute Regime, Adib J. Samin
Faculty Publications
High entropy alloys (HEAs) are promising candidates for high-temperature structural material applications. Oxidation is a major factor that must be accounted for when designing such materials and it is thus important to study the oxidation behavior of HEAs to enable the optimum design of next generation materials. In this study, the thermodynamic behavior of interstitial oxygen in a Mo-Nb-Ta-W high entropy alloy was explored beyond the dilute limit. This was accomplished by sampling configurations of the HEA and HEA-oxygen systems from an isothermal–isobaric ensemble using a series of first-principle-based Monte Carlo simulations. It was found that the interstitial oxygen had …
Development Of Corrosion Inhibiting Geopolymers Based Cement For Transportation Infrastructure, Homero Castaneda, Miladin Radovic, Changkyu Kim, Oscar Huang
Development Of Corrosion Inhibiting Geopolymers Based Cement For Transportation Infrastructure, Homero Castaneda, Miladin Radovic, Changkyu Kim, Oscar Huang
Data
Geopolymers are gaining attention as affordable, sustainable, and eco-friendly replacement for Ordinary Portland Cement (OPC) in concrete civil structures. More importantly, Geopolymer-based Cement (GPC) provide sustainable and environmentally friendly alternative to OPCs as GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g., fly ash) or abounded natural sources (e.g., clay) and thus reduce significant CO2 production associated with processing of OPC. Although, a lot of work has been done on improving mechanical properties of GPC over the last two decades, there are only a few studies on effects of GPC concrete on steel rebar …
Development Of Corrosion Inhibiting Geopolymers Based Cement For Transportation Infrastructure, Homero Castaneda, Miladin Radovic, Changkyu Kim, Oscar Huang
Development Of Corrosion Inhibiting Geopolymers Based Cement For Transportation Infrastructure, Homero Castaneda, Miladin Radovic, Changkyu Kim, Oscar Huang
Publications
Geopolymers are gaining attention as affordable, sustainable, and eco-friendly replacement for Ordinary Portland Cement (OPC) in concrete civil structures. More importantly, Geopolymer-based Cement (GPC) provide sustainable and environmentally friendly alternative to OPCs as GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g., fly ash) or abounded natural sources (e.g., clay) and thus reduce significant CO2 production associated with processing of OPC. Although, a lot of work has been done on improving mechanical properties of GPC over the last two decades, there are only a few studies on effects of GPC concrete on steel rebar …
Longer Service Life Bridge Coatings, Danny Wells, Theodore Hopwood, Bobby Meade, Sudhir Palle
Longer Service Life Bridge Coatings, Danny Wells, Theodore Hopwood, Bobby Meade, Sudhir Palle
Kentucky Transportation Center Research Report
The Kentucky Transportation Cabinet (KYTC) has maintenance oversight responsibilities for approximately 1,100 steel bridges; it also helps local governments and other entities with maintenance painting on other steel bridges. Because maintaining steel bridges is costly, Cabinet officials asked Kentucky Transportation Center (KTC) researchers to identify materials and methods that will prolong their service lives. Steel bridges are uniquely vulnerable to deterioration resulting from exposure to atmospheric conditions (e.g. moisture, ultraviolet rays) and chlorides, the latter due to the application of deicing materials. This study examines two strategies for extending service lives. First, it appraises a novel method of hot dip …
Prototype System For Implementing The Ultrasonic Guided Wave Method On The Field, Ece Erdogmus, Eric Garcia, Michael Schuller, Ahmad Shoaib Amiri
Prototype System For Implementing The Ultrasonic Guided Wave Method On The Field, Ece Erdogmus, Eric Garcia, Michael Schuller, Ahmad Shoaib Amiri
Nebraska Department of Transportation: Research Reports
This report presents the latest improvements in a recently developed nondestructive testing (NDT) technique for early detection of various flaws such as corrosion, delamination, and concrete cracking in reinforced concrete (RC) bridge decks. The method, named Ultrasonic Guided Wave Leakage (UGWL) method by the developing authors, involves use of internal steel reinforcement (rebar) as a wave guide for transmitting ultrasonic waves through the system and the measurement of leaked energy at the surface of the concrete. This report builds upon the progress made in the previously published phases of the project (M029 and M066), and aims to further explore the …
Prediction On Service Life Of Concrete Pipeline Buried In Chlorinated Environment Under Nonuniformly Distributed Earth Pressure, Lin Li, Weibing Gong, Jingpei Li
Prediction On Service Life Of Concrete Pipeline Buried In Chlorinated Environment Under Nonuniformly Distributed Earth Pressure, Lin Li, Weibing Gong, Jingpei Li
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
This paper proposes an analytical model to estimate the service life of concrete pipelines buried in chloride contaminated soils, which properly considers the effects of nonuniformly distributed earth pressures on both the internal tensile stress of concrete protective cover and the chloride diffusion coefficient through the nonhomogeneous coefficient of earth pressure. It is assumed that the underground concrete pipeline arrives at the service life end when cracking induced by expansion pressure due to the corrosion products occurs in the concrete protective cover. Hence, the whole service life of underground concrete pipeline is composed of chloride diffusion period and protective cover …
Bridge Resilience Assessment With Inspire Data, Iris Tien, Yijian Zhang
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 …
A Novel Structural Health Monitoring Method For Reinforced Concrete Bridge Decks Using Ultrasonic Guided Waves, Ece Erdogmus, Eric Garcia, Ahmad Shoaib Amiri, Michael Schuller
A Novel Structural Health Monitoring Method For Reinforced Concrete Bridge Decks Using Ultrasonic Guided Waves, Ece Erdogmus, Eric Garcia, Ahmad Shoaib Amiri, Michael Schuller
Durham School of Architectural Engineering and Construction: Faculty Publications
This article presents the latest improvements in a recently developed nondestructive testing (NDT) approach for early detection of various flaws (corrosion, delamination, and concrete cracking) in reinforced concrete (RC) bridge decks. The proposed method involves the use of internal steel reinforcement as a wave guide for transmitting ultrasonic waves through the system and the measurement of leaked energy from the surface of the concrete. This paper builds upon the progress made in the previously published phases of the project and aims to further explore the capabilities and practicality of the proposed NDT method. Specifically, the limits of propagation distance, effect …
Degradation Mechanism Due To Water Ingress Effect On The Top Contact Of Cu(In,Ga)Se2 Solar Cells, Deewakar Poudel, Shankar Karki, Benjamin Belfore, Grace Rajan, Sushma Swaraj Atluri, Sina Soltanmohammad, Angus Rockett, Sylvain Marsillac
Degradation Mechanism Due To Water Ingress Effect On The Top Contact Of Cu(In,Ga)Se2 Solar Cells, Deewakar Poudel, Shankar Karki, Benjamin Belfore, Grace Rajan, Sushma Swaraj Atluri, Sina Soltanmohammad, Angus Rockett, Sylvain Marsillac
Electrical & Computer Engineering Faculty Publications
The impact of moisture ingress on the surface of copper indium gallium diselenide (CIGS) solar cells was studied. While industry-scale modules are encapsulated in specialized polymers and glass, over time, the glass can break and the encapsulant can degrade. During such conditions, water can potentially degrade the interior layers and decrease performance. The first layer the water will come in contact with is the transparent conductive oxide (TCO) layer. To simulate the impact of this moisture ingress, complete devices were immersed in deionized water. To identify the potential sources of degradation, a common window layer for CIGS devices—a bilayer of …