Digital Commons Network^™

Developments In Performance Monitoring Of Concrete Exposed To Extreme Environments., W. J. Mccarter, T. M. Chrisp, G. Starrs, A. Adamson, E. Owens, P. A. M. Basheer, S. V. Nanukuttan, S. Srinivasan, Niall Holmes

Articles

The performance of the surface zone of concrete is acknowledged as a major factor governing the rate of deterioration of reinforced concrete structures because it provides the only barrier to the ingress of water containing dissolved ionic species such as chlorides, which ultimately initiate corrosion of the reinforcement. In situ monitoring of cover-zone concrete is therefore critical in attempting to make realistic predictions as to the in-service performance of the structure. To this end, this paper presents developments in a remote interrogation system to allow for continuous, real-time monitoring of the cover-zone concrete from an office setting. Use is made …

Bias Correction And Downscaling Of Climate Model Outputs Required For Impact Assessments Of Climate Change In The U.S. Northeast, Kazi F. Ahmed

Master's Theses

Global Climate Models (GCMs) are the typical sources of future climate data required for impact assessments of climate change. However, GCM outputs are related to model-related uncertainties and involve a great deal of biases. Bias correction of model outputs is, therefore, necessary before their use in impact studies. The coarse resolution of GCM simulations is another hindrance to their direct use in fine-scale impact analysis of climate change. Although downscaling of GCM outputs can be performed by dynamical downscaling using Regional Climate Models (RCMs), it requires large computational capacity. When daily climate data from multiple GCMs are required to be …

Adapting To Climate Change While Planning For Disaster: Footholds, Rope Lines, And The Iowa Floods, Robert R.M. Verchick, Abby Hall

BYU Law Review

No abstract provided.

2011 Fall Engr333 Project Final Report, Fall 2011 Engr333

ENGR 333

Analysis of the Bunker Interpretive Center (BIC) began during the spring of 2011 with the Engineering 382 Instrumentation Lab. To determine the energy use at the BIC, sensing equipment was placed on 44 different energy consuming devices, ranging from pumps to lights to heating and ventilation (HVAC) equipment. These data were collected over the spring and summer and then analyzed by the Engineering 333 Thermal Systems Design class during the fall of 2011. The class was tasked with determining whether or not the BIC was eligible for Energy Star certification. While the building was built to be LEED Gold certified, …

Safety Issues Among Hispanic Construction Workers Along The Wasatch Front In Utah, Phavel Israel Loayza Chahuayo

Theses and Dissertations

During the last few decades immigration by foreigners seeking work in the construction industry in the United States has increased dramatically. Of those seeking jobs in construction, Hispanics represent the largest and fastest growing population. The proportion of reportable accidents among Hispanic on-site construction workers in the United States is higher than that of non-Hispanics. This trend of on-site construction accidents is evident not only in states that have traditionally high populations of Hispanics, such as New York, Florida, California, Arizona, and Texas, it is also manifested in the State of Utah. This research focused on causes of accidents among …

Damage Tolerance Of Unidirectional Basalt/Epoxy Composites In Co-Cured Aramid Sleeves, Devin Nelson Allen

Theses and Dissertations

Unidirectional basalt fiber rods consolidated with an aramid sleeve were measured for compression strength after impact at various energy levels and compared to undamaged control specimens. These structural elements represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® technologies) that are continuously fabricated using advanced three-dimensional braiding techniques. The unidirectional core specimens, nominally 8 mm (5/16") and 11 mm (7/16") in diameter, were manufactured using bi-directional braided sleeves or unidirectional spiral sleeves with full or partial (approximately half) coverage of the core fibers. The 51 mm (2") specimens were shorter than the critical buckling …

Damage Tolerance Of Buckling-Critical Unidirectional Carbon, Glass,And Basalt Fiber Composites In Co-Cured Aramid Sleeves, Michael D. Embley

Theses and Dissertations

Compression strength after impact tests were conducted on unidirectional composite rods with sleeves. These elements represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® technologies). The unidirectional cores composed of carbon, glass, or basalt fiber/epoxy composites were co-cured in aramid sleeves. Sleeve patterns included both bi-directional (unsymmetric) braids and unidirectional spiral wraps with sleeve coverage ranging from nominally half to full. The diameters were nominally 8 and 11 mm (5/16 and 7/16 in). The larger diameter had nominally twice the cross-sectional area, to quantify the effects of scaling. The specimens were long enough to …

Strength Of Concrete Masonry Prisms Constructed With Non-Traditional Grout And Type-M Mortar, Scott Michael Watterson

Theses and Dissertations

The Concrete Masonry Association of California and Nevada in conjunction with Brigham Young University devised a masonry prism testing scheme to aid in the determination of whether prisms constructed with grouts possessing high levels of supplemental cementitious materials could meet minimum masonry compressive strength requirements. ASTM standards, identical to that of concrete, place restrictions on quantities, by weight, of supplemental materials that can replace ordinary Portland cement. For an all fly ash replacement, up to 40% of Portland cement can be replaced while up to 70% can be replaced by a fly ash-slag combination. Research is focused on class F …

Reduction In Wick Drain Effectiveness In Typical Utah Clays, Gabriel M. Smith

Theses and Dissertations

Consolidation theory states that decreasing the spacing of prefabricated vertical drains will decrease the time required to achieve primary consolidation. Previous field tests have shown that there exists a "critical" drain spacing, which is the point at which further spacing decrease does not decrease the time of primary consolidation. This "critical" spacing is thought to be due to disturbance effects from installation of the drains. Previous studies have found that the "critical" drain spacing may be dependent upon soil layering and drain and mandrel dimensions. Thin, interbedded clay layers have been found to be affected greatly due to the smear …

2011 Fall Engr333 Student Seminar Presentation, 2011 Fall Engr333

ENGR 333

File for student presentation, given by students in the Fall 2010 class of ENGR333.

The Cuahsi Community Hydrologic Information System (Invited), David G. Tarboton, D. R. Maidment, I. Zaslavsky, Daniel Ames, J. L. Goodall, R. P. Hooper, Jeffery S. Horsburgh

Civil and Environmental Engineering Faculty Publications

Hydrologic information is collected by many individuals and organizations in government and academia for many purposes, including general monitoring of the condition of the water environment and specific investigations of hydrologic processes. Comprehensive understanding of hydrology requires integration of this information from multiple sources. The Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) has developed a Hydrologic Information System (HIS) to provide better access to data by enabling the publication, cataloging, discovery and retrieval of hydrologic data using web services. This paper describes HIS capability developed to promote data sharing and interoperability in the Hydrologic Sciences with …

Determining A Community Retrofit Strategy For The Aging Housing Stock Using Utility And Assessor Data, Nathan A. Barry

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Residential buildings account for about 21.5% of the nation’s primary energy consumption and carbon emissions, and about 38% of electricity use. The housing stock in the United States consists of over 128 million residences with over 60% being constructed prior to 1979 when building codes and regulations began standardizing building practices. Seeking an opportunity to understand and reduce consumption, the scientific community developed a number of model-driven auditing software. While these computer models have been successful in predicting usage patterns in newer residential structures, they have been inaccurate in predicting and analyzing energy use in aging housing stock, predominantly homes …

Virtual Microstructure Generation Of Asphaltic Mixtures, Mohammad Haft-Javaherian

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis describes the development and application of a virtual microstructure generator incorporated with post-processing image analysis methods that can be used to fabricate a virtual, two-dimensional microstructure of asphaltic mixtures. In the generator, geometrical characteristics such as aggregate gradation, aggregate area fraction, angularity, orientation, and elongation were used to transform data from a three-dimensional (3D) mixture into its two-dimensional (2D) microstructure. The 2D virtual microstructures were generated from real 3D mixture information of asphaltic composites. Resulting virtual microstructures were then compared to real cross-sectional microstructure images obtained from actual samples for validation. Comparison presented a good agreement between the …

A New Method Of Producing High Strength Oil Palm Shell Lightweight Concrete, Hilmi Mahmud

Hilmi Mahmud

This paper presents a new method to produce high strength lightweight aggregate concrete (HSLWAC) using an agricultural solid waste, namely oil palm shell (OPS). This method is based on crushing large old OPS. Crushed OPS are hard and have a strong physical bond with hydrated cement paste. The 28 and 56. days compressive strength achieved in this study were about 53 and 56. MPa, respectively. Furthermore, it was observed that it was possible to produce grade 30 OPS concrete without the addition of any cementitious materials. Compared to previous studies, significantly lower cement content was used to produce this grade …

Designing Carbon Taxation Schemes For Automobiles: A Simulation Exercise For Germany, Adamos Adamou, Sofronis Clerides, Theodoros Zachariadis

Theodoros Zachariadis

Vehicle taxation based on CO2 emissions is increasingly being adopted worldwide in order to shift consumer purchases to low-carbon cars, yet little is known about the effectiveness and overall economic impact of these schemes. We focus on feebate schemes, which impose a fee on high-carbon vehicles and give a rebate to purchasers of low-carbon automobiles. We estimate a discrete choice model of demand for automobiles in Germany and simulate the impact of alternative feebate schemes on emissions, consumer welfare, public revenues and firm profits. The analysis shows that a well-designed scheme can lead to emission reductions without reducing overall welfare.

Effects Of Calcium Addition On Structure And Bioavailability Of Soil Organic Matter, Ankit Balaria

Civil and Environmental Engineering - Dissertations

The northeastern USA has a long history of acid rain, which has impacted soil fertility and raised concerns about the sustainability of the forests in the region. To facilitate recovery of these forests, calcium addition, in the form of wollastonite, was evaluated as a remedial tool at Hubbard Brook Experimental Forests in New Hampshire, USA. In order to study the effects of these amendments on soil organic matter and soil microbes, I characterized the structural chemistry of soil organic matter (SOM) and its hot-water extractable organic matter (HWEOM) fraction for Hubbard Brook soils and studied the changes in the structure …

Multiscale/Multiphysics Modeling Of Concrete Structures, Yang Lu

Yang Lu

Concrete structure modeling is not easy. Cement concrete has a complex microstructure, which is still not completely elucidated. A lot of study has been carried out in cement concrete materials and structures modeling. The microstructure of concrete contains random features over a wide range of length scales, from nanometers to millimeters, with each length scale presenting a random composite. In its engineering uses, concrete is considered as a uniform material at the length scale of meters. Concrete research topics include complex failure processes, such as, atomic scale cementitious hydration, micro-pore structure formation and moisture transport in microstructure, calcium ion transport …

Water Quality Monitoring Of An Urban Stream For Total Maximum Daily Load Assessment, Jeffrey K. Mihulka

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The purpose of this research project was to assess the water quality of an urban stream for total maximum daily load assessment in Omaha, Nebraska. This was accomplished by sampling the water quality at four different sites. These sites included sampling upstream, within, and downstream of the city. These samples were conducted throughout 2010 and 2011.

The results showed that concentrations of Escherichia coli (E. coli) are routinely above established criteria for the state of Nebraska. Concentrations of E. coli that exist in the Papillion Creek Watershed upstream of the City of Omaha have also been shown to be above …

Sensitivity Analysis On Mapping Evapotranspiration At High Resolution Using Internal Calibration (Metric), Venkata Naga Ravi Kumar Choragudi

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Mapping EvapoTranspiration at high Resolution using Internal Calibration (METRIC) is most widely used to quantify evapotranspiration (ET) spatially and temporally. It is essential to inspect the model’s response to errors in various parameters used in the model. Landsat 5 images from May 30 2009, July 1 2009 and a Landsat 7 image from September 27 2009 are used in this study. Fourteen different fields composed of Corn, Soybeans, Alfalfa are randomly chosen for each crop type.

Two kinds of errors are addressed in this study. One, with the errors that are transferred and potentially compensated by calibration (Global error) and …

Calibration Of Highway Safety Manual: Predictive Models For Oregon State Highways, Fei Xie, Kristie Gladhill, Karen Dixon, Christopher Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

The recently released "Highway Safety Manual" (HSM) published by AASHTO provides a comprehensive set of tools for evaluating and identifying opportunities to improve safety for highway facilities. Included in the HSM is a quantitative method for predicting crashes on the basis of recently developed scientific approaches. These predictive methods currently exist for three facility types: rural two-lane roads; rural multilane highways; and urban and suburban arterial highways. To enhance precision, each HSM predictive method should be calibrated for location conditions. This paper demonstrates the HSM calibration procedure for total crashes in Oregon. The research identified three critical data collection limitations …

Evaluation Of Pre-Consolidation Stress Determination Methods, Omar Conte, Stephanie Rust, Louis Ge, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Pre-Consolidation Pressure Provides Valuable Information About Soil Behavior And, Specifically, Settlement under an Induced Load. Soil is Expected to Have Less Settlement Before its Pre-Consolidation Pressure and Much More Settlement after that Point. the Pre-Consolidation Pressure and the Compressibility of the Soil Can Be Determined from the Results of a One-Dimensional Consolidation Test. Different Methods Have Been Developed to Obtain the Accurate Pre-Consolidation Pressure from One Dimensional Consolidation Test Data. This Paper Presents and Discusses the Results of the One-Dimensional Consolidation Test Data from an Extensive Testing Program. the Test Specimens Used Were Obtained from Multiple Borehole Locations and Were …

Modeling Unbound Granular Materials Under Complex Stress Paths, Cheng Chen, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Developing reliable and versatile constitutive models for geomaterials has been challenging tasks for nonlinear finite element analysis of geotechnical engineering systems. the fuzzy set plasticity theory has been developed to account for the nonlinear soil stress-strain response under complex stress paths. the theory in many ways resembles the bounding surface plasticity, where the plastic modulus is a function of the distance between the current and image stress states in the stress space. based on the concept of fuzzy set theory in mathematics, a membership function whose value ranges from 1 and 0 is introduced in the Fuzzy Set Plasticity Theory …

Application Of Threshold Concepts To Improve A Design-Focused Course In Transportation Engineering, Dan Cernusca, Ghulam Bham

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Design is an integral part of engineering courses. to address its associated problems, however, is a challenging task in instruction because of design's open-endedness and complexity. in this study, two theoretical models were implemented in an introductory transportation engineering course to address the challenges associated with design of a highway. First, the theoretical framework proposed by the threshold concepts model was used to identify a candidate concept for the instructional redesign process. Two major characteristics of threshold concepts, integrativity and transformativity, were used to identify horizontal alignment as a candidate concept for the highway design process. Second, concept mapping was …

Characterization Of Crushed Rock-Concrete Interface Behavior Through The Parallel Gradation Technique, Domenica Cambio, Xin Kang, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The response of a soil-structure system subjected to monotonic or cyclic loading is influenced significantly by the mechanical behavior of soil-structure interface. in this paper, the friction characteristics of the crushed rock-concrete interface and the role of the crushed rock deformability were examined through a series of monotonic and cyclic direct shear tests. the physical modeling technique of parallel gradation was adopted where two parallel gradation curves of the crushed rocks were prepared and used in the tests. the tests were carried out in dry condition and with two initial void ratios representing both loose and dense states. Two concrete …

Regeneration Of Carbon Aerogel Exhausted In Water Purification, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Carbon has been used electrochemically in various forms for water treatment and the carbon aerogel is one of them. Carbon Aerogels (CA) are used as electrodes due to their high surface capacity and high electrical conductivity. They are also known as Carbon Nanofoams (CNF). CA electrodes attract oppositely charged ions that are nearby. This concept is known as Capacitive De-Ionization (CDI). The use of CA in CDI for water purification is well documented, but not much work has been done on regeneration of CA electrodes. Once saturated, these electrodes lose their ability to adsorb additional ions and it must be …

The Role Of Eddies Inside Pores In The Transition From Darcy To Forchheimer Flows, Kuldeep Chaudhary, M. Bayani Cardenas, Wen Deng, Philip C. Bennett

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

We studied the role of intra-pore eddies, from viscous to inertial flows, in modifying continuum-scale flow inside pores. Flow regimes spanning Reynolds Number Re ∼ 0 to 1350 are divided into three zones - one zone follows Darcy flow, and the other two zones describe non-Darcy or Forchheimer flow. During viscous flows, i.e., Re < 1, stationary eddies occupy about 1/5 of the pore volume. Eddies grow when Re > 1, and their growth leads to the deviation from Darcy's law and the emergence of Forchheimer flow manifested as a characteristic reduction in the apparent hydraulic conductivity K_a. The reduction in K_a is due to the narrowing of the flow channel which is …

Measuring Global Response Of A Wind Turbine To Simulated Earthquake Shaking Assisted By Point Tracking Videogrammetry, Ian Prowell, Tim Schmidt, Ahmed Elgamal, Chia Ming Uang, Hal Romanowitz, J. Edward Duggan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Experiments investigating earthquake response of structures traditionally use conventional wired instruments such as strain gauges, displacement transducers, and accelerometers deployed at key areas of interest throughout structure. for wind turbines the rotor is one of these key areas, but due to rotation it is not possible to use wired instruments without a special slip ring. in a recent experiment conducted using the Network for Earthquake Engineering Simulation (NEES) Large High Performance Shake Table (LHPOST) at the University of California, San Diego (UCSD) the global response of a full scale 65-kW turbine (22 m hub height) was monitored using a novel …

Ole Miss Engineer 2011-2012

Ole Miss Engineer

No abstract provided.

Flood Routing In Natural Channels Using Muskingum Methods, Safa Elbashir

Other resources

The accuracy of flood routing is an important subject for research in hydrology and hydraulics. Accurate information of the flood peak attenuation and the duration of the high water levels obtained by channel routing are of most importance in flood forecasting operations and flood protection works (Subramanya, 2008). This study implements two hydrological methods for channel routing, the basic Muskingum and the constant coefficient Muskingum-Cunge methods on the River Brosna, Co. Offaly in Ireland. Previous researches have reported the simplicity and applicability of these methods on most natural streams within certain limits. These limitations are encountered in the River Brosna …

Modeling Passive Solar Distillation Production In Las Vegas, Nevada, Noe I. Santos

UNLV Theses, Dissertations, Professional Papers, and Capstones

A study has been performed to examine the effects of daily weather on the performance of commercial solar distillation basins (solar stills). The objectives of this study were to evaluate the long term performance of solar stills, to instrument two solar stills and record sub-hourly thermal properties, to evaluate existing heat transfer modeling methods for hourly production, and to create new models to predict daily production using experimental distillate production and local weather data by utilizing artificial neural networks, genetic algorithms, and multivariate regression. A system dynamics model was also created to determine the required basin area and storage volume …