The Transportation Of Corrosion Products In Cementitious Material Under Chloride-Rich Environment,
2022
Zhejiang University
The Transportation Of Corrosion Products In Cementitious Material Under Chloride-Rich Environment, Yuzhou Wang
International Conference on Durability of Concrete Structures
Corrosion products, forming on steel bar in cementitious material, can lead to concrete cracking. Clear the transportation of corrosion products is of great significance to predict corrosion-induced structural deterioration. This study investigates the corrosion products in steel-reinforced concrete specimen. By Raman spectroscopy and SEM method, the chemical constituents and micromorphology of corrosion products at steel-concrete interface as well as those inside the pore of cement paste are investigated. The proportion of corrosion products filling into the cement paste is determined by EDTA titration method. The results reveal that corrosion products diffuse in forms of ion in solution under chloride-rich environment, …
Research On Water Absorption And Frost Resistance Of Concrete Coated With Different Impregnating Agents For Ballastless Track Structure,
2022
China Academy of Railway Sciences
Research On Water Absorption And Frost Resistance Of Concrete Coated With Different Impregnating Agents For Ballastless Track Structure, Xin Ge, Yanbin Tan, Xiaowei Wang, Yongjiang Xie, Qinfei Li, Linxiang Li, Lu Yang, Zhongwei Feng
International Conference on Durability of Concrete Structures
In consideration of performance requirement of ballastless track concrete in cold regions of China, 3 types of commercially available impregnating agents were employed to research their effect on water absorption and frozen resistance of concrete, containing silanes, potassium silicate and osmotic curing agent. The results presented that coating silanes was the most effective on the reduction of water absorption among all employed impregnating agents, because of the most significant character change of concrete surface from hydrophilicity to hydrophobicity which could be proved by the contact angle test of concrete. The promotion on frozen resistance of concrete was not as significant …
Study On Corrosion Resistance Of Portland Cement-Calcium Sulphoaluminate Cement Binary System In A Sodium Chloride Environment,
2022
Nanjing Tech University
Study On Corrosion Resistance Of Portland Cement-Calcium Sulphoaluminate Cement Binary System In A Sodium Chloride Environment, Shilin Song, Tao Xing, Yu Zhang, Jianzheng Wang, Xiaodong Shen, Ying Ma
International Conference on Durability of Concrete Structures
Portland cement is widely used in civil engineering. However, Portland cement-based materials are easy to be corroded by seawater in marine environment. Many research show the corrosion resistance of Portland cement mortar can be improved by add appropriate amount of mineral admixture.Sulphoaluminate cement have high strength and good corrosion seawater resistance. However, the short setting time and high hydration heat of sulphoaluminate cement limit its application in civil engineering.Portland cement-sulphoaluminate cement (PC-CSA) not only have high strength and corrosion resistance but also long setting time.In this work, the sulphoaluminate cement was used to partially replace Portland cement. The replacement level …
Predicting Tensile Strength For Prestressed Reinforced Concrete-Driven Piles,
2022
The University of Texas Rio Grande Valley
Predicting Tensile Strength For Prestressed Reinforced Concrete-Driven Piles, Thuyet N. Nguyen, Thang Pham, Thuy Vu, Adnan A. Malik, Duc N. Dinh
Civil Engineering Faculty Publications
Reinforced concrete piles installed by impact hammers have been used as a common solution for deep foundations because they are cost effective and require less time for construction. Driven piles are often used in large volumes for infrastructure and industrial projects in rural areas. Unlike other installation methods, installing piles using impact hammers can generate tensile stress during construction, which can result in pile failures. Induced tensile stress occurs when piles are being driven through a hard soil layer to a softer soil layer, and transverse cracks happen when induced tensile stress exceeds the pile tensile strength. This issue is …
Anthropogenic Stressors Compound Climate Impacts On Inland Lake Dynamics: The Case Of Hamun Lakes,
2022
Boise State University
Anthropogenic Stressors Compound Climate Impacts On Inland Lake Dynamics: The Case Of Hamun Lakes, Arash Modaresi Rad, Jason Kreitler, John T. Abatzoglou, Kendra Fallon, Kevin R. Roche, Mojtaba Sadegh
Civil Engineering Faculty Publications and Presentations
Inland lakes face unprecedented pressures from climatic and anthropogenic stresses, causing their recession and desiccation globally. Climate change is increasingly blamed for such environmental degradation, but in many regions, direct anthropogenic pressures compound, and sometimes supersede, climatic factors. This study examined a human-environmental system – the terminal Hamun Lakes on the Iran-Afghanistan border – that embodies amplified challenges of inland waters. Satellite and climatic data from 1984 to 2019 were fused, which documented that the Hamun Lakes lost 89% of their surface area between 1999 and 2001 (3809 km2 versus 410 km2), coincident with a basin-wide, multi-year …
Performance Modeling And Analysis Of A Thermoelectric Building Envelope For Space Heating,
2022
Purdue University
Performance Modeling And Analysis Of A Thermoelectric Building Envelope For Space Heating, Xiaoli Liu, Ming Qu, Kazuaki Yazawa, Jorge Kohanoff, Piotr Chudzinski, Lorenzo Stella, Brian Norton, Niall Holmes Dr., Ruchita Jani, Hongxi Yin
Conference papers
To provide energy-efficient space heating and cooling, a thermoelectric building envelope (TBE) embeds thermoelectric devices in building walls. The thermoelectric device in the building envelope can provide active heating and cooling without requiring refrigerant use and energy transport among subsystems. Thus, the TBE system is energy and environmentally friendly. A few studies experimentally investigated the TBE under limited operating conditions, and only simplified models for the commercial thermoelectric module (TEM) were developed to quantify its performance. A holistic approach to optimum system performance is needed for the optimal system design and operation. The study developed a holistic TBE-building system model …
Structural Health Monitoring Of Fatigue Cracks For Steel Bridges With Wireless Large-Area Strain Sensors,
2022
University of South Carolina
Structural Health Monitoring Of Fatigue Cracks For Steel Bridges With Wireless Large-Area Strain Sensors, Sdiq Anwar Taher, Jian Li, Jong-Hyun Jeong, Simon Laflamme, Hongki Jo, Caroline Bennett, William N. Collins, Austin Downey
Faculty Publications
This paper presents a field implementation of the structural health monitoring (SHM) of fatigue cracks for steel bridge structures. Steel bridges experience fatigue cracks under repetitive traffic loading, which pose great threats to their structural integrity and can lead to catastrophic failures. Currently, accurate and reliable fatigue crack monitoring for the safety assessment of bridges is still a difficult task. On the other hand, wireless smart sensors have achieved great success in global SHM by enabling long-term modal identifications of civil structures. However, long-term field monitoring of localized damage such as fatigue cracks has been limited due to the lack …
The Effects Of Recycled Waste On Concrete Mixture Properties,
2022
Kennesaw State University
The Effects Of Recycled Waste On Concrete Mixture Properties, Noral Hadbawi
Master of Science in Civil Engineering Theses
Recent years have seen an exponential increase in plastic product consumption worldwide. Manufacturing, and individuals rely on plastics in almost every aspect, as a result, a negative impact on the environment is detected due to the large quantities and low biodegradability of plastic waste. The massive amount of plastic waste and end-of-life tires produced annually required a vast area of landfills, which became a major concern far and wide. To address these issues, an eco-friendly approach consisting of incorporating plastic and rubber waste into engineering applications, such as plastic concrete, and rubberized concrete was proposed. A primary objective of this …
A Deep Learning Image Segmentation Model For Agricultural Irrigation System Classification,
2022
Shiraz University
A Deep Learning Image Segmentation Model For Agricultural Irrigation System Classification, Ehsan Raei, Ata Akbari Asanjan, Mohammad Reza Nikoo, Mojtaba Sadegh, Shokoufeh Pourshahabi, Jan Franklin Adamowski
Civil Engineering Faculty Publications and Presentations
Effective water management requires a large-scale understanding of agricultural irrigation systems and how they shift in response to various stressors. Here, we leveraged advances in Machine Learning and availability of very high resolution remote sensing imagery to help resolve this long-standing issue. To this end, we developed a deep learning model to classify irrigation systems at a regional scale using remote sensing imagery. After testing different model architectures, hyper parameters, class weights and image sizes, we selected a U-Net architecture with a Resnet-34 backbone for this purpose. We applied transfer learning to increase training efficiency and model performance. We considered …
Influence Of Rainfall-Induced Erosion On The Stability Of Sandy Slopes Treated By Micp,
2022
Tennessee State University
Influence Of Rainfall-Induced Erosion On The Stability Of Sandy Slopes Treated By Micp, Shihui Liu, Kang Du, Kejun Wen, Catherine Armwood-Gordon, Lin Li
Civil and Architectural Engineering Faculty Research
As an environmentally friendly technology, microbially induced calcite precipitation (MICP) is widely used to improve the engineering properties of soil. The goal of this study was to investigate the effect of rainfall-induced erosion on the stability of sandy slopes which were treated by MICP technology. The observation of the erosion pattern of low concentration (0.25 M Ca) and high concentration (0.5 M Ca) of MICP-treated slopes, the mechanical behaviors of MICP-treated and cement-treated samples, and the effects of rainfall-induced erosion on the roughness of 0.5 M Ca MICP-treated and 10% cement-treated slope were studied through visual observation, unconfined compressive tests, …
Experimental Study And Piezoresistive Mechanism Of Electrostatic Self-Assembly Of Carbon Nanotubes–Carbon Black/Epoxy Nanocomposites For Structural Health Monitoring,
2022
Dalian University of Technology
Experimental Study And Piezoresistive Mechanism Of Electrostatic Self-Assembly Of Carbon Nanotubes–Carbon Black/Epoxy Nanocomposites For Structural Health Monitoring, Yanlei Wang, Yao Fu, Ziping Meng, Baolin Wan, Baoguo Han
Civil and Environmental Engineering Faculty Research and Publications
Since electrostatic self-assembly carbon nanotubes–carbon black (CNTs–CB) composite fillers have good electrical conductivity and an easy dispersion process, they were incorporated into epoxy matrix to fabricate the CNTs–CB/epoxy nanocomposites. The mechanical properties, electrical conductivity, piezoresistivity, as well as microstructure characterization of the CNTs–CB/epoxy nanocomposites were experimentally investigated. The piezoresistive mechanisms of the CNTs–CB/epoxy nanocomposites were also established based on tunneling conduction and contacting conduction. The significant improvements in compressive yielding strength and elastic modulus of the nanocomposites could be attributed to the stable interfacial interaction. A moderate percolation threshold was obtained at 0.41 vol% for the CNTs–CB/epoxy nanocomposites in comparison …
Meta-Analysis Of The Prevalence Of Dissolved Organic Nitrogen (Don) In Water And Wastewater And Review Of Don Removal And Recovery Strategies,
2022
Marquette University
Meta-Analysis Of The Prevalence Of Dissolved Organic Nitrogen (Don) In Water And Wastewater And Review Of Don Removal And Recovery Strategies, Synthia P. Mallick, Zayed Mallick, Brooke K. Mayer
Civil and Environmental Engineering Faculty Research and Publications
Most wastewater removal and recovery processes primarily target dissolved inorganic nitrogen (DIN) species, leaving the untreated non-reactive dissolved organic nitrogen (DON) in the effluent. This DON fraction can account for a substantial part of the total nitrogen (N) load. We analyzed large datasets of N species and concentrations (with a focus on quantifying the fraction of DON) in surface water, ground water, and wastewater effluent across the United States. We then reviewed strategies to remove and recover DON based on results of a range of treatment technologies reported in the literature, including laboratory-scale up to full-scale operation in wastewater treatment …
Simple Rebar Anchorage Slip Macromodel Considering Corrosion,
2022
The University of Akron
Simple Rebar Anchorage Slip Macromodel Considering Corrosion, Ahmad Soraghi, Qindan Huang
Civil and Environmental Engineering Faculty Research and Publications
Reinforcement slip in the footing of a reinforced concrete (RC) column can significantly influence the lateral displacement of the column, a critical structural response under lateral loads such as seismic loading. Many past researchers studied and developed models to capture the anchorage slip of rebar; however, there is still a need for a model that can reflect the actual bond-slip relationship (especially in the presence of corrosion) and yet is simple-to-use for structural analysis. In this study, a simple bar stress-slip macromodel is developed to predict reinforcement anchorage slip given a rebar stress. The proposed rebar anchorage slip model is …
Seasonal And Spatial Patterns Differ Between Intracellular And Extracellular Antibiotic Resistance Genes In Urban Stormwater Runoff,
2022
Marquette University
Seasonal And Spatial Patterns Differ Between Intracellular And Extracellular Antibiotic Resistance Genes In Urban Stormwater Runoff, Kassidy N. O'Malley, Patrick J. Mcnamara, Walter M. Mcdonald
Civil and Environmental Engineering Faculty Research and Publications
Antibiotic resistance is a public health threat that is exacerbated by the dispersion of antibiotic resistance genes (ARGs) into aquatic environments. Urban stormwater runoff has been recognized as a source of and a mechanism by which intracellular ARGs (iARGs) can be transported into receiving environments. The prevalence and behavior of extracellular ARGs (eARGs) in stormwater, however, has yet to be considered. This study quantified four iARGs and eARGs under baseflow and stormflow conditions. Urban stormwater runoff was found to be a source of all the ARGs examined, with the absolute concentration of all iARGs and two eARGs (ermF …
Sequential Electrolysis And Reverse Osmosis To Improve Arsenic Removal From Water,
2022
Marquette University
Sequential Electrolysis And Reverse Osmosis To Improve Arsenic Removal From Water, Yizhi Hou, Brooke K. Mayer
Civil and Environmental Engineering Faculty Research and Publications
Reverse osmosis (RO) typically removes >98% arsenate (As[V]) but removes arsenite (As[III]) comparatively poorly (approximately 50%–80%). Therefore, oxidizing As(III) to As(V) can improve arsenic removal using RO. In this study, electrolytic oxidation was used to oxidize As(III) in the feed water, and an extreme low-pressure RO membrane was subsequently used to remove the arsenic. Using Ti/IrO2 electrodes under 30 mA DC current in 500 mg/L NaCl solution primarily generated free chlorine, which completely oxidized 300 μg/L As(III) to As(V). Subsequent arsenic removal by RO increased from 54.2% without oxidation to 98.2% with oxidation. Using electrolysis-RO, arsenic removal significantly increased beyond …
Impact Of Stormwater Infiltration On Rainfall-Derived Inflow And Infiltration: A Physically Based Surface–Subsurface Urban Hydrologic Model,
2022
Marquette University
Impact Of Stormwater Infiltration On Rainfall-Derived Inflow And Infiltration: A Physically Based Surface–Subsurface Urban Hydrologic Model, Kun Zhang, Anthony J. Parolari
Civil and Environmental Engineering Faculty Research and Publications
The subsurface fate of stormwater infiltration enhanced by green infrastructure (GI) is unknown. GI redirects stormflows from the surface into the subsurface, which can be partitioned to evapotranspiration or baseflow, or be intercepted by buried infrastructure trenches. Stormwater that infiltrates sanitary sewer pipes is referred to as rainfall-derived inflow and infiltration (RDII) and represents a rapid pathway for infiltrated stormwater to reach receiving waters. To quantify the partitioning of infiltrated stormwater between slow and fast flows, a physically-based hydrologic model was developed integrating coupled surface–subsurface processes and urban sewer systems and applied to a sewershed near Milwaukee, WI. In this …
Lab-Scale Data And Microbial Community Structure Suggest Shortcut Nitrogen Removal As The Predominant Nitrogen Removal Mechanism In Post-Aerobic Digestion (Pad),
2022
Black & Veatch
Lab-Scale Data And Microbial Community Structure Suggest Shortcut Nitrogen Removal As The Predominant Nitrogen Removal Mechanism In Post-Aerobic Digestion (Pad), Fabrizio Sabba, Patrick J. Mcnamara, Eric Redmond, Mike Young, Leon Downing
Civil and Environmental Engineering Faculty Research and Publications
Implementing an aerobic digestion step after anaerobic digestion, referred to as “post aerobic digestion” (PAD), can remove ammonia without the need for an external carbon source and destroy volatile solids. While this process has been documented at the lab-scale and full-scale, the mechanism for N removal and the corresponding microbial community that carries out this process have not been established. This research gap is important to fill because the nitrogen removal pathway has implications on aeration requirements and carbon demand, that is, short-cut N-removal requires less oxygen and carbon than simultaneous nitrification–denitrification. The aims of this research were to (i) …
Oxidized Graphitic Nano-Amendment Of Cement Composites: Exploring Truly Low Concentrations And Novel Particle Morphologies,
2022
University of South Carolina
Oxidized Graphitic Nano-Amendment Of Cement Composites: Exploring Truly Low Concentrations And Novel Particle Morphologies, Shohana Iffat
Theses and Dissertations
Oxidized graphitic nanoparticles such as multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs), can produce enhancements in physicomechanical properties of cement composites that are relevant to structural and durability performance, provided that said nanoparticles are well dispersed in the composite. Lower-bound MWCNT concentrations are reported in the literature in the range 0.01-0.05% in weight of cement (wt%). Such concentrations may not be costeffective for practical applications and may also be excessive since they would result in a nanoparticle surface area at or above 105 m2 for 1 m3 of cement paste, or 104.5 m2 for 1 m 3 of concrete, …
Changes In Drought Characteristics Under Future Climate Projections,
2022
Florida Institute of Technology
Changes In Drought Characteristics Under Future Climate Projections, Diogo Stalin De Alcantara Araujo
Theses and Dissertations
Accumulating evidence on the impact of climate change on droughts, highlight the necessity for developing effective adaptation and mitigation strategies. Global Drought Layers were developed for historic and future runs of nine global climate models (GCM) of the Coupled Model Intercomparison Model 6th phase (CMIP6). Relative changes of drought characteristics were estimated, and hotspots were identified, especially in South America, Africa, Europe, Western USA, and Australia. Further, changes in future drought risk and severity in Australia are quantified. Historic conditions (1981-2014) and projections for mid-century (2015-2050) and end-century (2051-2100) from four shared socioeconomic pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) are …
Circular Reinforced Concrete Columns Damaged By Fire And Retrofitted With Cfrp And Steel Jacketing,
2022
Syracuse University
Circular Reinforced Concrete Columns Damaged By Fire And Retrofitted With Cfrp And Steel Jacketing, Jia Xu
Dissertations - ALL
In recent decades, the post-fire behavior of reinforced concrete (RC) columns with normal and high-strength concrete has become an important research topic. Numerous studies have demonstrated that RC columns exhibit good fire resistance owing to the thermal properties of concrete. Therefore, reinforced concrete structures rarely collapse within a finite fire duration and can be successfully repaired. Along with the increasing number of skyscrapers, high-strength concrete (HSC) has played an equally important role as normal-strength concrete (NSC) in the industry. In this study, the thermal behavior of RC columns with NSC and HSC exposed to ISO 834 standard fire for various …
