Engineering Commons^™

Effects Of Warm-Mix Asphalt Additives On Asphalt Mixture Characteristics And Pavement Performance, Jun Zhang

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

The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera synthetic zeolite) were evaluated. For a more realistic evaluation of the WMA approaches, trial pavement sections of the WMA mixtures and their HMA counterparts were implemented in Antelope County, Nebraska. More than one ton of field-mixed loose mixtures were collected at the time of paving and were transported to the NDOR and UNL laboratories to conduct comprehensive laboratory evaluations and pavement performance predictions of the …

Soil Behavior Under Blast Loading, Jichong An

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

Understanding the behavior of soil under blast loading is very important to engineers in mining, tunneling, and military construction. Due to the very complex structure of a soil mass it is very difficult to describe its constitutive relation, especially when it has different water contents and it is under blast loading conditions. New protective system designs subjected to blast loading need to be proved its validation prior to predict effect of explosive before implementation. Full-scale, buried explosive tests are costly. Finite element simulations play a significant role in the design of protective systems, for example a bottom platform of lightweight …

A Generalized Non-Parametric Approach For Uncertainty Evaluation In Travel Time Prediction Models, Bhaven Naik

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

A core component within Advanced Traveler Information Systems is travel time information because it is easily understood and perceived by travelers. However, the suggested travel time information should be based not only on historical and real-time conditions, but also on forecasted or “unknown” future conditions.

Existing research has focused primarily on developing models that forecast point estimates of the mean travel time that are in close comparison to their respective field values. There has been limited research on any insight into the reliability or uncertainty margin that exists around the forecasted point estimate. As well, these researches have a limitation …

Embedded Radio Frequency Identification Device License Plates For Roadside Use In Nebraska, Dwight L. Mosby Jr

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

The transportation industry has many stakeholders with different needs that work with advanced technologies. Radio Frequency Identification (RFID) is an emerging technology that is used to track inventory and it holds promise for the transportation industry. This research identifies how to evaluate transportation stakeholder requirements for RFID technologies using a tool described as the House of Quality (HOQ). This research investigates RFID’s ability to work in license plates and may provide infrastructure to support identifying RFID enabled commercial vehicles. This research considers variables that affect the performance of a RFID License Plate System that will use a scanner located at …

The Green, Blue And Grey Water Footprint Of Farm Animals And Animal Products. Volume 1: Main Report, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

The projected increase in the production and consumption of animal products is likely to put further pressure on the globe’s freshwater resources. The size and characteristics of the water footprint vary across animal types and production systems. The current study provides a comprehensive account of the global green, blue and grey water footprints of different sorts of farm animals and animal products, distinguishing between different production systems and considering the conditions in all countries of the world separately. The following animal categories were considered: beef cattle, dairy cattle, pig, sheep, goat, broiler chicken, layer chicken and horses. The study shows …

The Green, Blue And Grey Water Footprint Of Farm Animals And Animal Products. Volume 2: Appendices, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Contents

Appendix I: Feed conversion efficiencies – in kg of feed (dry mass) per kg of output – per animal category and region

Appendix II: Estimated consumption of feed per animal category and world region (10³ ton dry mass/yr)

Appendix III. Estimated consumption of feed per production system and world region (10³ ton dry mass/yr)

Appendix IV. Drinking and service water footprint per animal

Appendix V. Water footprint of animals and animal products (m³/ton). Period 1996-2005

Performance Evaluation Of Brass Breakaway Couplings, Joseph G. Putjenter, Scott K. Rosenbaugh, Karla A. Lechtenberg, Ronald K. Faller, Dean L. Sicking, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Dynamic Impact Testing Of Wood Posts For The Midwest Guardrail System Placed Adjacent To A 2h:1v Fill Slope, Karla A. Lechtenberg, Robert W. Bielenberg, Ronald K. Faller, Dean L. Sicking, Mary D. Mcghee, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of The Mgs Approach Guardrail Transition Using Standardized Steel Posts, Scott K. Rosenbaugh, Ronald K. Faller, Robert W. Bielenberg, Karla A. Lechtenberg, Dean L. Sicking, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Investigating The Use Of A New Universal Breakaway Steel Post -- Phase Iii, Dean L. Sicking, Ronald K. Faller, Robert W. Bielenberg, Karla A. Lechtenberg, Jennifer D. Schmidt

Nebraska Department of Transportation: Research Reports

No abstract provided.

Second Generation Precast Deck Panel (Nudeck) System, Kromel E. Hanna, George Morcous, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Layer Moduli Of Nebraska Pavements For The New Mechanistic Empirical Pavement Design Guide, Soohyok Im, Yong-Rak Kim, Hoki Ban

Nebraska Department of Transportation: Research Reports

No abstract provided.

Hydraulic Conductivity, Infiltration, And Runoff From No-Till And Tilled Cropland, Jessica H. Deck

Department of Environmental Engineering: Theses and Student Research

Infiltration and runoff are important processes that affect the efficiency of center pivot irrigation systems. No-till planting systems potentially influence the hydraulic properties of soils and the soil surface conditions. The result of long-term use of no-till could be higher infiltration and lower runoff from rainfall and irrigation.

This potential was investigated in Nebraska on two center pivot irrigated sites; Fillmore County and Phelps County, one furrow irrigated site; South Central Agriculture Laboratory (SCAL), and one dryland site; Rogers Farm. Paired treatments were used at each location, one that was no-till planted and one that used two to three operations …

Comparison Of Subsurface And Surface Runoff Phosphorus Transport Capacities In Alluvial Floodplains, Aaron R. Mittelstet, Derek M. Heeren, Daniel E. Storm, Garey A. Fox, M. J. White, R. B. Miller

Biological Systems Engineering: Papers and Publications

There have been numerous studies on phosphorus (P) contributions from surface runoff, but studies comparing the contribution of surface versus subsurface P are limited, as subsurface transport is often considered negligible. Previous work has shown that the transport of P in the gravelly subsurface at two sites in northeast Oklahoma can be significant, especially in preferential flow paths (PFPs), hypothesized to be buried gravel bars. The objective of this project was to quantify subsurface P losses based on field data, and compare with surface runoff P losses derived from Pasture Phosphorus Management Calculator (PPM Plus) simulations. Ozark ecoregion study sites …

Changes In The Structure And Function Of Microbial Communities In Drinking Water Treatment Bioreactors Upon Addition Of Phosphorus, Xu Li, Giridhar Upadhyaya, Wangki Yuen, Jess Brown, Eberhard Morgenroth, Lutgarde Raskin

Department of Civil and Environmental Engineering: Faculty Publications

Phosphorus was added as a nutrient to bench-scale and pilot-scale biologically active carbon (BAC) reactors operated for perchlorate and nitrate removal from contaminated groundwater. The two bioreactors responded similarly to phosphorus addition in terms of microbial community function (i.e., reactor performance), while drastically different responses in microbial community structure were detected. Improvement in reactor performance with respect to perchlorate and nitrate removal started within a few days after phosphorus addition for both reactors. Microbial community structures were evaluated using molecular techniques targeting 16S rRNA genes. Clone library results showed that the relative abundance of perchlorate-reducing bacteria (PRB) Dechloromonas and Azospira …

Characterization And Pollutant Loading Estimation For Highway Runoff In Omaha, Nebraska, Camilo Torres

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

Stormwater from roadways could have negative effects on the environment. Typical highway runoff pollutants include heavy metals, petroleum hydrocarbons, gasoline constituents, PAHs (polyaromatic hydrocarbons), oxygen demanding compounds measured as COD (chemical oxygen demand) and BOD (biochemical oxygen demand), and road salts.

The objectives of this research were: characterize the pollutants in roadway runoff and determine the effectiveness of the existing stormwater BMPs at the study site. To accomplish these objectives, eleven rainfall events were sampled from November 2008 through November 2010.

First flush and composite highway runoff samples were analyzed for heavy metals, anions, nutrients, particulates, BOD, COD, VOCs, and …

Rapid Construction Of Pacific Street Bridge, Kromel E. Hanna, George Morcous, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Optimal Design Of Work Zone Median Crossovers, Karen Schurr, Brian R. Garnder, Shashwat Rijal

Nebraska Department of Transportation: Research Reports

No abstract provided.

Constructability Testing Of Folded Plate Girders, Luke A. Glaser

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

A new steel girder bridge system was developed at the University of Nebraska. The innovative girder design is a box girder folded from a single steel plate that has a trapezoid shape with an opening on the bottom. The girder has application in short span bridges and accelerated construction situations. The structural performance of the girder requires investigation in all stages of a bridge’s lifecycle. This thesis contains descriptions and results from the first two tests from a series of tests developed to evaluate this new girder shape. The objective of these two tests was to investigate the constructability of …

Experimental Investigation Of Folded Plate Girders And Slab Joints Used In Modular Construction, Kyle A. Burner

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

The folded plate girder, a newly proposed bridge girder, is investigated through this thesis. The folded plate girder is cold bent out of a single sheet of steel. The cold bending eliminates the costly and inconsistent shop welds found in traditional girders. The folded plate girder is meant for application in short span bridges. The girder was subjected to an equivalent 75 year lifetime loading to investigate the fatigue performance.

The rebar detail used in the closure region between adjacent slabs has been investigated in the past by the NCHRP 12-68 project. This thesis will proposes a hooked rebar detail …

Development Of Advanced Finite Element Material Models For Cable Barrier Wire Rope, John D. Reid, Karla A. Lechtenberg, Cody S. Stolle

Nebraska Department of Transportation: Research Reports

An improved LS-DYNA model of ¾-in. (19-mm) diameter 3x7 wire rope commonly used in roadside cable guardrail installations has been developed. A Belytschko-Schwer beam element was selected along with material *MAT_166. Numerical noise was reduced using part stiffness damping with a coefficient of 2%, and frequency range damping with a coefficient of 12%. The optimum element length based on timestep, accuracy, and computational cost was determined to be between 0.4 and 0.8 in. (10-20 mm). Dynamic component tests were conducted on wire rope to determine material properties. These tests were simulated and the results compared to the physical tests. The …

Bottom Flange Reinforcement In Nu I-Grinders, George Morcous, Kromel E. Hanna, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of A Low Cost, Energy-Absorbing Bridge Rail, Dean L. Sicking, Robert W. Bielenberg, Ronald K. Faller, Karla A. Lechtenberg, Scott K. Rosenbaugh, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

A Needs Assessment Of Highway Stakeholders Of An At–Grade Highway–Railroad Intersection In Lincoln, Nebraska, Ryan Haas

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

The University of Nebraska-Lincoln has deployed a data collection test bed along a rail

corridor in the City of Lincoln. The test bed spans about 2.5 miles along the corridor

which parallels Cornhusker Highway, with the focus placed on the Adams Street

highway rail grade crossing (HRGC). The test bed currently has some data-collecting

capabilities, but the possibility exists that there is additional data that could be useful to

various users of the rail crossings.

To gauge these possible unmet data needs of highway stakeholders, a needs

assessment was carried out by the author. A comprehensive literature review was done …

Impact Of Bottom Flange Confinement Reinforcement On Performance Of Prestressed Concrete Bridge Girders, Quinton Patzlaff

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

For many years AASHTO provided no recommendation to state DOT’s on bottom flange confinement reinforcement for their bridge superstructures. The 1996 edition of AASHTO Standard Specification for Highway Bridges stated that nominal reinforcement be placed to enclose the prestressing steel from the end of the girder for at least a distance equal to the girder’s height. A few years later the 2004 AASHTO LRFD Bridge Design Specification changed the distance over which the confinement was to be distributed from 1.0h to 1.5h, and gave minimum requirements for the amount of steel to be used, No.3 bars, and their maximum spacing, …

Design Aids Of Nu I-Grinder Bridges, Kromel Hanna, George Morcous, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of A Temporary Concrete Barrier To Permanent Concrete Median Barrier Approach Transition, Mitchell J. Wiebelhaus, Karla A. Lechtenberg, Ronald K. Faller, John R. Rohde, Ryan J. Terpsma, Robert W. Bielenberg, Dean L. Sicking, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Load Rating Of Complex Bridges, George Morcous, Kromel E. Hanna, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Foundation Design For High Tension Cable Guardrails, John R. Rohde, Ryan J. Terpsma, Ling Zhu

Nebraska Department of Transportation: Research Reports

No abstract provided.

Offset Right-Turn Lanes For Improved Intersection Sight Distance, Karen Schurr, Timothy J. Foss Jr.

Nebraska Department of Transportation: Research Reports

No abstract provided.