Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Climate change (8)
- Drinking water (5)
- Cold-formed steel (3)
- Traffic safety (3)
- Uncertainty (3)
-
- Water quality (3)
- Clay (2)
- Disinfection by-products (2)
- EPS (2)
- Ferrate (2)
- Micromechanics (2)
- Optimization (2)
- Oxidation (2)
- Paratransit (2)
- Pareto Frontier (2)
- Triaxial test (2)
- Wastewater (2)
- 100% choice set coverage (1)
- : Alkali activation; Carbon-based nanomaterials; Cavitation; Isothermal adsorption; Nanoindentation; Organosilanes; Sol-gel; Surface hierarchical; Superhydrophobicity (1)
- ANSI/APA PRG 320 (1)
- Abrasion (1)
- Adaptive routing (1)
- Additive manufacturing (1)
- Adsorptive contactors (1)
- Aeration-free wastewater treatment (1)
- Agency Cost (1)
- Agent-based (1)
- Agent-based model (1)
- Aggregation (1)
- Algae (1)
Articles 1 - 30 of 85
Full-Text Articles in Engineering
Drivers’ Hazard Avoidance During Vehicle Automation: Impact Of Mental Models And Implications For Training, Ganesh Pai Mangalore
Drivers’ Hazard Avoidance During Vehicle Automation: Impact Of Mental Models And Implications For Training, Ganesh Pai Mangalore
Doctoral Dissertations
Advanced Driver Assistance Systems (ADAS) are vehicle automation systems that have become more accessible and prevalent in vehicles in recent years. But the introduction of such technologies introduces new human factors challenges. Past literature suggests that users of vehicle automation lack the necessary and appropriate knowledge about their automation system. This may play a negative role in their hazard avoidance abilities when driving with automation features. Improving mental models and knowledge could generally lead to safer interactions with vehicle automation systems, but any effort to develop hazard avoidance skills when driving with vehicle automation is impeded by the lack of …
Steel Deck Diaphragms: Characterizing The Hysteretic Behavior Of Light Gage Steel, Screw-Fastened, Support And Sidelap Connections And The Influence Of Support Connections On The Stability Behavior Of Panels, Divyansh Kapoor
Doctoral Dissertations
Steel deck diaphragms are planar structures that serve as critical components of a metal building’s lateral force-resisting system. These can be found in walls, floors, and roofs of metal buildings and aid with the lateral stability of the structure. The diaphragm design process involves the selection of materials, deck geometry, connections, and connection detailing across the steel panels. The American Iron and Steel Institute’s AISI S310 and Steel Deck Institutes DDM04 both provide design guidance on the selection and detailing of materials and fasteners for the applicable limit states of connections and stability of the panels. Both design codes provide …
Functionalizing Three-Dimensional Superhydrophobic Materials, Li He
Functionalizing Three-Dimensional Superhydrophobic Materials, Li He
Doctoral Dissertations
Traditional bulk superhydrophobic materials are usually characterized by high porosity, low fracture toughness, and extremely low strength due to the low surface energy on the internal surface. Therefore, it is very challenging to achieve a bulk superhydrophobic material with high strength and mechanical durability. This dissertation presents an experimental study of strengthening a superhydrophobic siloxane using carbon-based nanomaterials, emphasizes the effects of microscale dispersion and macroscale distribution of reinforcing graphene on the uniformity and strength of the composite, studies the impact factors on the water adsorption for hydrophilic and hydrophobic materials, and applies chemical modification modify the surface of clay …
Water Resources Planning Under Deep Uncertainty For Physically, Socially, And Politically Complex Systems, Sarah St. George Freeman
Water Resources Planning Under Deep Uncertainty For Physically, Socially, And Politically Complex Systems, Sarah St. George Freeman
Doctoral Dissertations
Water supply systems, particularly those of large cities, are complex systems linking supply, regulatory and distribution infrastructure, and points of use. Despite their physical complexities, it is infrequent that full supply, distribution, end use, and feedbacks therein are considered in an integrated manner. These complex systems-of-systems face large uncertainties related to physical aspects such as degradation of infrastructure, changing demand, and climate variability and change. Though great, such physical uncertainties often pale in comparison to the those related to the human systems in place to manage them and yet uncertainty in the decision-making landscape is often grossly simplified in our …
Predicting Water Quality Vulnerability Under Climate Change With Machine Learning, Khanh Thi Nhu Nguyen
Predicting Water Quality Vulnerability Under Climate Change With Machine Learning, Khanh Thi Nhu Nguyen
Doctoral Dissertations
Water quality deterioration is a global and pervasive issue due to pollution caused by industrialization, urbanization, agriculturalization, and human population growth in the modern era. This issue is even more challenging in the context of climate change due to warming temperatures and the intensification of precipitation. Therefore, assessing the potential impacts of climate change on water quality is a concern. Assessment is necessary so that planners can prepare for and reduce the negative impacts on water quality. At present, climate change impact assessment frameworks are relatively adolescent. Most studies rely on climate projections from General Circulation Models for simulations of …
Experimental Investigation Of Clay Aggregate And Granular Biofilm Behavior, Tao Jiang
Experimental Investigation Of Clay Aggregate And Granular Biofilm Behavior, Tao Jiang
Doctoral Dissertations
Clay minerals are a class of phyllosilicates as the major solid constituents in cohesive fine-grained soils (e.g., clays). Owing to their tiny size (i.e., < 2 μm), high aspect ratio, and active surface properties that inherit from the geological process, clay minerals can extensively interact with other suspended matter (e.g., exoployemers, microorganisms) and dissolved ions via the process of flocculation and aggregation, resulting in the formation of larger, porous cohesive particulate aggregates or flocs. Such a complex mechanism of microscale particle interaction generates significant challenges for understanding the bulk clay behavior as a particulate system. In order to better characterize the flocculation and aggregation of clay minerals under various stimuli and to understand the underlying mechanism of particle interactions, particle/aggregate size kinetics of flocculated suspensions of illite, a representative 2:1 clay mineral abundant in marine soils, are studied with varied ionic strength induced by monovalent salt (NaCl), pH, and hydrodynamic shearing in the first phase of this research. Furthermore, a new statistical data binning method termed “bin size index” (BSI) was employed to determine the probability density function (PDF) distributions of flocculated illite suspensions. The statistical results demonstrate that the size kinetics of flocculated illite suspensions is chiefly controlled by the face-to-face and edge-to-face interparticle interactions under the mutual effects of ionic strength and pH, while the hydrodynamic shearing has minimal effects on the variation of particle size groups. In the second phase of this research, the mechanics of clay aggregates are studied using an innovative measurement technique and analytical approach. Individual clay minerals prepared with different mineralogy and salinities are tested via unconfined compression, which shows that the increasing ionic strength can improve the strength and stiffness of clay aggregates, which are further affected by the mineralogical compositions and dominant microfabric in different water chemistry. In the final phase of this research, a collaborative study with an environmental engineer on an NSF CAREER project was conducted to investigate the mechanical behavior of macroscale, light-induced oxygenic granules (biofilm aggregates) using the same technique and analytics developed for the individual clay aggregates. The findings are expected to provide reference values to subsequent studies and engineering practices associated with the water treatment process.
Lateral Response Of Cold-Formed Steel Diaphragms With Variable Sheathing, Hernan Castaneda
Lateral Response Of Cold-Formed Steel Diaphragms With Variable Sheathing, Hernan Castaneda
Doctoral Dissertations
Cold-formed steel (CFS) framed buildings and subsystems have demonstrated safe and reliable performance while under lateral and seismic loads. Combined with their structural efficiency, this makes CFS-framed buildings popular choice even in high seismic zones. However, due to the complexity in response of CFS members and their interaction in subsystem and system levels, more research needs to be conducted to better understand the overstrength in the system, as well as the contribution of non-structural components to the overall response of the building. The lateral force resisting system (LFRS) of CFS framed buildings consist primarily of shear walls and diaphragms. The …
Optimizing Transportation Systems With Information Provision, Personalized Incentives And Driver Cooperation, Sayeeda Ayaz
Optimizing Transportation Systems With Information Provision, Personalized Incentives And Driver Cooperation, Sayeeda Ayaz
Doctoral Dissertations
Poor performance of the transportation systems has many detrimental effects such as higher travel times, increased travel costs, higher energy consumption, and greenhouse gas emissions, etc. This thesis optimizes the transportation systems by addressing the traffic congestion problem and climate change impact resulting from the inefficient operation of these systems. I first focus on the key player of the transportation systems e.g., human being/traveler, and model travelers' route choice behavior with real-time information. In this study, I define looking-ahead behavior in route choice as a traveler's taking into account future diversion possibilities enabled by real-time information in a network with …
Remote Sensing Of High Latitude Rivers: Approaches, Insights, And Future Ramifications, Merritt E. Harlan
Remote Sensing Of High Latitude Rivers: Approaches, Insights, And Future Ramifications, Merritt E. Harlan
Doctoral Dissertations
High latitude rivers across the pan-Arctic domain are changing due to changes in climate and positive Arctic feedback loops. Understanding and contextualizing these changes is challenging due to a lack of data and methods for estimating and modeling river discharge, and mapping rivers. Remote sensing, and the availability of satellite imagery can provide ways to overcome these challenges. Through combining various forms of fieldwork, modeling, deep learning, and remote sensing, we contribute methodologies and knowledge to three key challenges associated with better understanding high latitude rivers. In the first chapter, we combine field data that can be rapidly deployed with …
Enhancing Management Of Built And Natural Water And Sanitation Systems With Data Science, Nelson Da Luz
Enhancing Management Of Built And Natural Water And Sanitation Systems With Data Science, Nelson Da Luz
Doctoral Dissertations
In the age of the data revolution, the civil engineer can enhance the management of infrastructure systems using new techniques focused on data. This dissertation present three studies in which data science approaches are used to enhance management of water and sanitation systems in both the built and natural environments. Chapters 1 and 2 focus on improving methods for data collection relating to water quality monitoring. In Chapter 1, the efficacy of different water quality sampling program designs is evaluated as the programs relate to meeting monitoring goals. Considerations include how timing, location, and distribution system operations can affect monitoring …
Equitable Resource Allocation To Improve Safety: An Evaluation Based On Risk, Alyssa M. Ryan
Equitable Resource Allocation To Improve Safety: An Evaluation Based On Risk, Alyssa M. Ryan
Doctoral Dissertations
Transportation safety continues to be a serious issue throughout the world. Proven safety measures have been developed to increase the safety on all roadways, but have not been universally and equitably implemented due to lack of resources, inefficiencies, and understanding. Additionally, the relative level of mobility safety remains higher in certain environments than others, creating an inequitable landscape. In this dissertation, the efficiency of using local and statement resources to improve safety is investigated while controlling for level of safety risk in vulnerable environments and locations using a comprehensive approach. Several methodologies and techniques are employed and developed to examine …
The Role Of Extracellular Polymeric Substances In The Accumulation And Transport Of Polystyrene Nanoparticles In Biofilms, Joann Marie Rodríguez Suarez
The Role Of Extracellular Polymeric Substances In The Accumulation And Transport Of Polystyrene Nanoparticles In Biofilms, Joann Marie Rodríguez Suarez
Doctoral Dissertations
With the increasing number of nanotechnology applications, it is reasonable to expect nanoparticles to be ubiquitous in biofilms found in natural and engineered aquatic systems. We studied the impact of the degree of cross-linking on the deposition and diffusion of polystyrene nanoparticles (NPs) in alginate model biofilm matrices in the presence and absence of calcium cross-linkers using image correlation methods and single particle tracking. We found that cross-linking increases the viscoelasticity and hydration of the polymeric matrix and leads to structural changes that can restrict and alter the diffusive behavior of NPs, but the magnitude of the effects on diffusion …
Assessing The Impact Of Bicycle Treatments On Bicycle Safety: A Multi-Methods Approach, Aikaterini Deliali
Assessing The Impact Of Bicycle Treatments On Bicycle Safety: A Multi-Methods Approach, Aikaterini Deliali
Doctoral Dissertations
Compared to other modes, bicyclists are disproportionally affected by crashes considering their low mode share. There is evidence that crashes between bicyclists and motorized vehicle take place at road segments and signalized intersections where bicycle treatments (e.g., bike lanes) are present, urging for in-dept analysis of the safety impact of the various bicycle treatment types. Additionally, it is important to identify sensor types that have the potential to advance field data collection and traffic monitoring in multi-modal road environments. In this dissertation, three approaches, namely crash analysis, traffic conflict analysis, and analysis of driver speeding and glancing behavior, were implemented …
Analysis And Fate Of 2,6-Dichloro-1,4-Benzoquinone In Real And Model Drinking Waters, Aarthi Mohan
Analysis And Fate Of 2,6-Dichloro-1,4-Benzoquinone In Real And Model Drinking Waters, Aarthi Mohan
Doctoral Dissertations
For many years chlorination has served as a barrier to protect human health from waterborne disease outbreaks. Chlorine is viewed as a near-universal oxidant and disinfectant, that provides a stable residual preventing microbial re-growth all the way through the consumer’s tap. Upon reaction with natural organic matter (NOM) however, it forms disinfection by-products (DBPs) many of which are potent human carcinogens and therefore have been of research interest since the 1970’s (Froese et al., 1999; Krasner et al., 2006, 1989; Richardson, 2003; Rook, 1976, 1974; Singer, 1994). The trihalomethanes (THMs) and haloacetic acids (HAAs) are the most prevalent (Krasner et …
Size Progression Of Oxygenic Photogranules (Opgs) And Its Effect On Opg Wastewater Treatment, Ahmed S.A. Abouhend
Size Progression Of Oxygenic Photogranules (Opgs) And Its Effect On Opg Wastewater Treatment, Ahmed S.A. Abouhend
Doctoral Dissertations
In recent years, the oxygenic photogranule (OPG) process has gained increasing interest because of its potential to treat wastewater without supplemental aeration. Oxygenic photogranules (OPGs) are dense spherical aggregates comprised of phototrophic and nonphototrophic microorganisms. In OPG wastewater treatment reactors, photogranules grow in number as well as in size. The primary goal of this dissertation was to investigate how OPGs grow in size and how the growth affects their structure and functions. We found that OPGs undergo structural changes as they grow bigger in size. As OPGs grow larger, filamentous cyanobacteria become enriched while other phototrophic microbes diminish significantly. OPGs …
Big Data Nanoindentation: Concepts, Principles And Applications To Cemented Materials, Yucheng Li
Big Data Nanoindentation: Concepts, Principles And Applications To Cemented Materials, Yucheng Li
Doctoral Dissertations
The exploration of oil/gas in the petroleum industry presents a lot of issues both during and after the drilling process, such as wellbore stability, formation clogging, and cementation. Understanding the chemo-mechanical alterations caused by drilling activities to the surrounding formations has been a crucial part of a successful drilling operation. However, as multi-phases, multi-scales, heterogeneous composites, the mechanical properties of rock can vary significantly with its diverse constituent minerals (e.g., quartz, feldspar, and clay minerals) and sometimes hard to be characterized due to the availability of rock samples (i.e., cylindrical core samples are arduous to acquired especially at deep formations). …
A Comprehensive Protocol For Inspection And Assessment Of Aging Steel Bridges: Experiments, Computations And 3d Laser Scanning Of Field Corroded Girders, Georgios Tzortzinis
A Comprehensive Protocol For Inspection And Assessment Of Aging Steel Bridges: Experiments, Computations And 3d Laser Scanning Of Field Corroded Girders, Georgios Tzortzinis
Doctoral Dissertations
According to a recent evaluation, our nation's infrastructure has increasingly presenting signs of deterioration with some elements exhibiting significant deficiencies in conditions and functionality. Regarding the transportation network condition, from the over than 600,000 bridges which are included in the National Bridge Inventory, 46,154 of them are characterized as structurally deficient with the backlog of bridge rehabilitation needs estimated at US$125 billion. Among the many aspects of structural deficiency, corrosion is considered a common cause, both for reinforced concrete and steel bridge deterioration. For steel bridges, corrosion has historically triggered bridge failures resulting to fatalities and injuries. To prevent similar …
Density State And Shear Behavior Of Granular Soils With Influence Of Particle Size Distribution, Yibing Deng
Density State And Shear Behavior Of Granular Soils With Influence Of Particle Size Distribution, Yibing Deng
Doctoral Dissertations
Heterogeneous granular soils are ubiquitous in nature and man-made deposits. Heterogeneity of soil is characterized by its particle size distribution (or fines content for gap-graded soils). The particle size distribution of soil is the main factor that affects its mechanical properties. However, in soil mechanics, the influence of particle size distribution on mechanical properties is only considered in an empirical manner. There are few analytical methods that can explicitly account for the effect of particle size distribution. In this study, there are two purposes: 1) to develop a particle packing theory for modeling the effect of particle size distribution on …
Extracellular Polymeric Substances In Oxygenic Photogranules: Investigation Of Their Role In Photogranulation In A Hydrostatic Environment, Wenye Camilla Kuo-Dahab
Extracellular Polymeric Substances In Oxygenic Photogranules: Investigation Of Their Role In Photogranulation In A Hydrostatic Environment, Wenye Camilla Kuo-Dahab
Doctoral Dissertations
The purpose of this dissertation was to assess the critical role of extracellular polymeric substances (EPS) in the photogranulation of activated sludge, in a hydrostatic environment. The first section evaluates the fate and dynamics of different fractions of EPS in sludge-based photogranulation under hydrostatic conditions. The study shows that during the transformation of activated sludge into a photogranular biomass, sludge’s base-extractable proteins selectively degrade. Strong correlations between base-extracted proteins and the growth of chlorophyll a and chlorophyll a/b ratio suggest that the bioavailability of this organic nitrogen is linked with selection and enrichment of filamentous cyanobacteria under hydrostatic conditions. The …
Multiscale Investigation Of Thixotropy In Soft Clays, Jing Peng
Multiscale Investigation Of Thixotropy In Soft Clays, Jing Peng
Doctoral Dissertations
Fine-grained clay particles of <2 >µm in size are ubiquitous in soils and sedimentary rocks. Due to their platy shape, high aspect ratio, and surface charges, clay particles play a dominant role in controlling the mechanical properties of those fine-grained geomaterials such as soft clays and shales. In physics and engineering, some materials show that the strength and stiffness increases with time even if the boundary conditions remain unchanged (e.g., no change in pressure, temperature, or composition), and such a phenomenon is called thixotropy. It is generally agreed that the principle of thixotropy of wet clays is complex. For a closed, …
Understanding The Safety Impacts Of Left-Turn Infrastructure On The Vulnerable Driving Population, Francis Tainter
Understanding The Safety Impacts Of Left-Turn Infrastructure On The Vulnerable Driving Population, Francis Tainter
Doctoral Dissertations
The severe impact of roadway fatalities has remained a significant concern for researchers in recent years. As of 2015, traffic fatalities were the leading cause of death for individuals between the ages of 15 and 20 years old and a significant safety concern for drivers over the age of 65 years old (otherwise known as the “vulnerable” driving population). Intersection-related crashes have also remained prevalent in these demographic categories. Through four primary crash data evaluations, this dissertation explores the safety implications on the “vulnerable” driving population in the Commonwealth of Massachusetts. Through the utilization of newly developed crash data linkage …
Material Property Heterogeneity In Dimensional Lumber And Its Relationship To Mass Timber Performance, Fiona O'Donnell
Material Property Heterogeneity In Dimensional Lumber And Its Relationship To Mass Timber Performance, Fiona O'Donnell
Doctoral Dissertations
According to the Environmental Protection Agency, buildings account for 38% of the United States' carbon dioxide emissions, providing architects and structural engineers a unique opportunity to mitigate a significant factor driving climate change by implementing innovative and sustainable technology in infrastructure design. Wood and mass timber products are becoming an increasingly popular alternative building material due to their economic and environmental benefits. The natural growth of wood leads to highly heterogeneous material properties. Defects such as checks, knots, and localized slope of grain contribute to some of this variation; however, wood properties vary significantly even in clear wood. Using mass …
Harnessing The Mechanics Of Thin-Walled Metallic Structures: From Plate-Lattice Materials To Cold-Formed Steel Shear Walls, Fani Derveni
Harnessing The Mechanics Of Thin-Walled Metallic Structures: From Plate-Lattice Materials To Cold-Formed Steel Shear Walls, Fani Derveni
Doctoral Dissertations
Thin-walled structures have received a lot of interest during the last years due to their light weight, cost efficiency, and ease in fabrication and transportation, along with their high strength and stiffness. This dissertation focuses on the mechanical performance of thin-walled metallic structures from cold-formed steel shear walls and connections (PART I) to plate-lattice architected materials (PART II) via computational, experimental, and probabilistic methods. Cold-formed steel (CFS) shear walls subjected to seismic loads is the focus of PART I of this dissertation. An innovative three-dimensional shell finite element model of oriented strand board (OSB) sheathed CFS shear walls is introduced …
Buckling Of Thin Cylindrical Shells: Imperfection Sensitivity, Non-Destructive Technique For Capacity Prediction And Application For Wind Turbine Towers, Kshitij Kumar Yadav
Buckling Of Thin Cylindrical Shells: Imperfection Sensitivity, Non-Destructive Technique For Capacity Prediction And Application For Wind Turbine Towers, Kshitij Kumar Yadav
Doctoral Dissertations
The presence of imperfections significantly reduces the load-carrying capacity of thin cylindrical shells and the reduction depends on the shape and the size of the imperfections. As a result, the prediction of the shells' buckling capacity requires a priori knowledge about the imperfections---a difficult, expansive, and time-consuming adventure, if not impossible. Consequently, thin cylindrical shells are designed conservatively using the knockdown factor approach that accommodates the uncertainties associated with the imperfections present in the cylinders; almost all the design codes follow this approach explicitly or implicitly. However, cylindrical shells can be designed more efficiently by making them insensitive to imperfections, …
Optimization And Technology-Based Strategies To Improve Public Transit Performance Accounting For Demand Distribution, Charalampos Sipetas
Optimization And Technology-Based Strategies To Improve Public Transit Performance Accounting For Demand Distribution, Charalampos Sipetas
Doctoral Dissertations
Public transit is important to societies worldwide. The operation of public transit systems is generally associated with great benefits for the users, but there are also cases in which these systems demonstrate inefficient performance. Quantifying transit performance is an important area of research over the last decades. This dissertation presents models to improve transit system performance through optimization techniques and new technologies, recognizing the effects of non-uniform distribution of demand over space and time. The contributions span fixed route transit services and on-demand transit, as well as models for flexible transit operations that lie in between. Regarding fixed route systems, …
Cold-Formed Steel Stud Assemblies Bearing On Concrete Slabs, Abbas Joorabchian
Cold-Formed Steel Stud Assemblies Bearing On Concrete Slabs, Abbas Joorabchian
Doctoral Dissertations
Cold-formed steel (CFS) bearing walls are frequently installed on concrete slabs, which do not provide perfectly rigid and uniform bearing conditions. Existing design guidance assumes bearing conditions have no impact on the axial capacity, though cold-formed steel compressive members are particularly susceptible to end conditions. Studs are typically installed at the edge of concrete slabs, which is prone to spalling and geometric irregularities. Moreover, they are occasionally installed inadvertently overhanging from concrete slabs. In this research project, the impact of non-uniform and partial bearing conditions on the axial strength of cold-formed steel wall assemblies is identified and characterized experimentally and …
Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari
Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari
Doctoral Dissertations
Oxygenic photogranules (OPGs) are dense spherical microbial aggregates that are used for self-aerating wastewater treatment. Filamentous cyanobacteria are key granulating species, providing structural backbone and integrity in OPGs. Currently, the mechanisms for selecting filamentous cyanobacteria and their ability to form spherical OPGs are not well understood. Literature shows that iron (Fe) availability plays a significant role in the cyanobacterial growth and colony formation. Moreover, Fe availability is known to be dependent upon light, which is an essential growth substrate for the phototrophs. This research has investigated the role of Fe in the photogranulation phenomenon and the impact of light intensity …
Scaling Up The Oxygenic Photogranule (Opg) Wastewater Treatment Process, Joseph G. Gitau
Scaling Up The Oxygenic Photogranule (Opg) Wastewater Treatment Process, Joseph G. Gitau
Doctoral Dissertations
Photogranular biomass has yet to be utilized at large scale for wastewater treatment despite their potential to lower energy demand due to self-aerating capacity in addition to better process control compared to conventional technologies. An evaluation of critical driving factors affecting scaling up has yet to be undertaken. The current generation of oxygenic photogranules under hydrostatic conditions (a deviation from orthodox conditions creating other granules) limit seeding of larger reactors in time and scale. In addition, evaluating the photosynthetic productivity of granules which exist as closely commingled consortia with tightly coupled production and consumption processes, has yet to be undertaken. …
Characterization Of A Natural Clayey Silt And The Effects Of Sample Disturbance On Soil Behavior And Engineering Properties, Øyvind Blaker
Characterization Of A Natural Clayey Silt And The Effects Of Sample Disturbance On Soil Behavior And Engineering Properties, Øyvind Blaker
Doctoral Dissertations
Silts are considered a challenging material to deal with in geotechnical engineering design practice and there has been limited research on determining the engineering parameters of silts either by in situ or laboratory testing. This thesis presents results of an extensive research program that investigated the in situ and laboratory behavior of a low plasticity silt deposit at the Norwegian National Geotechnical Test Site at Halden, Norway. Results from multiple in situ tests including: piezocone, pore pressure dissipation, in situ pore pressure measurements, field vane, self-boring pressuremeter and screw plate load tests were synthesized to characterize the Halden silt. Soil …
Synthesis And Characterization Of Geopolymers Cast And Cured In Saline Water And The Potential Application In Construction Engineering, Xiaonan Ge
Doctoral Dissertations
The characteristics of underwater cast and cured geopolymers were experimentally studied to understand the interactions between geopolymer slurry and curing saline water and pertinent effects on its strength development. Geopolymers were synthesized from a mixture of Class C fly ash and metakaolin, and the influences of two different Si/Al molar ratios (1.78 and 2.00) and four different Na/Al (0.67, 0.80, 0.84, and 1.00) molar ratios were investigated, respectively. The geopolymer slurry was prepared and then cast into porous molds, followed by immediately submerged into 0, 15, and 35 ppt saline solutions (prepared with commercial seasalts) for 28-days’ curing in ambient …