Open Access. Powered by Scholars. Published by Universities.®
Civil and Environmental Engineering Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Transportation Engineering (331)
- Life Sciences (11)
- Physical Sciences and Mathematics (7)
- Plant Sciences (7)
- Agronomy and Crop Sciences (5)
-
- Ecology and Evolutionary Biology (4)
- Environmental Sciences (4)
- Horticulture (4)
- Agriculture (3)
- Arts and Humanities (3)
- History (3)
- Oceanography and Atmospheric Sciences and Meteorology (3)
- Social and Behavioral Sciences (3)
- Water Resource Management (3)
- Atmospheric Sciences (2)
- Behavior and Ethology (2)
- Geotechnical Engineering (2)
- History of Art, Architecture, and Archaeology (2)
- Meteorology (2)
- Other History of Art, Architecture, and Archaeology (2)
- Urban Studies and Planning (2)
- Animal Sciences (1)
- Apiculture (1)
- Architecture (1)
- Biology (1)
- Bioresource and Agricultural Engineering (1)
- Botany (1)
- Climate (1)
- Keyword
-
- NDOR (139)
- Transportation (85)
- Road (71)
- Street (30)
- Bridge (29)
-
- Safety (26)
- Pavement (25)
- Concrete (23)
- Highway (21)
- Asphalt (17)
- Nebraska (12)
- Guardrail (11)
- Highway Safety (11)
- Midwest guardrail system (11)
- Roadway (11)
- Barrier (10)
- Bridges (10)
- Roadside Appurtenances (9)
- Crash Test (8)
- Roads (8)
- Roadside (8)
- Crash (7)
- Vegetation (7)
- Construction (6)
- Design (6)
- Intersection (6)
- MASH (6)
- Median (6)
- Non-proprietary (6)
- Traffic (6)
- Publication Year
- File Type
Articles 61 - 90 of 335
Full-Text Articles in Civil and Environmental Engineering
Biopolymerized Slope/Subgrade Stabilization And Advanced Field Monitoring, Chung R. Song, Layla Bitar, Richard L. Wood, Yong-Rak Kim, Jongwan Eun, Binyam M. Bekele, Basil Abualshar
Biopolymerized Slope/Subgrade Stabilization And Advanced Field Monitoring, Chung R. Song, Layla Bitar, Richard L. Wood, Yong-Rak Kim, Jongwan Eun, Binyam M. Bekele, Basil Abualshar
Nebraska Department of Transportation: Research Reports
The slightly overconsolidated glacial tills and weathered shales in Midwestern states of the USA often show substantial strength degradation after construction. This strength reduction often causes time dependent slope failures along the roadside. This study investigated the possibility of applying biopolymer based soil modification techniques to mitigate the strength reduction phenomenon of these soils. For this research, several different biopolymers were evaluated through laboratory tests, two biopolymers were selected for extensive weathering tests, then a higher-performing biopolymer, Xanthan, was applied to a test slope in Verdigre, Nebraska with heavy instrumentation. The followings are the summary of the results.
The unweathered …
Low-Cost Modal Identification Sensors For Bridge Field Testing, Daniel Linzell, Saaed Eftekhar Azam, Samira Ardani, Ahmed E Rageh
Low-Cost Modal Identification Sensors For Bridge Field Testing, Daniel Linzell, Saaed Eftekhar Azam, Samira Ardani, Ahmed E Rageh
Nebraska Department of Transportation: Research Reports
This report provides a framework for experimental load rating of bridges via inclusion of low-cost dynamic sensors and dynamic tests. Currently 25% of the bridges in Nebraska are posted for live load. According to the National Bridge Inventory (NBI) in 2012, 93% of all postings in the US were based analytical load ratings, 7% were posted using field evaluation and engineering judgement, and 1% were posted using experimental load rating methods.
Instrumentation costs and traffic interruptions can be problematic when load testing is necessary to accurately assess in-situ bridge live load capacity. Recent advances in (i) sensing technology and (ii) …
Truck Platooning Effects On Girder Bridges, Joshua Steelman, Jay A. Puckett, Daniel Linzell, Bowen Yang
Truck Platooning Effects On Girder Bridges, Joshua Steelman, Jay A. Puckett, Daniel Linzell, Bowen Yang
Nebraska Department of Transportation: Research Reports
Truck platooning – digitally linking two or more trucks to travel in a closely spaced convoy – is increasingly used to save fuel, and reduce driver work and road congestion. Currently, the platoon load effects with several constant headways on bridges have been evaluated and compared to AASHTO design and legal loads. However, reliability assessment and a more rigorous investigation of headway spacing assumptions for truck platoons are lacking. This research provides a framework for determining how much a platoon permit load might be increased given strict control over the load characteristics and operational tactics. The present research evaluates the …
Research On Weather Conditions And Their Relationship To Crashes, Mark R. Anderson, Aemal Khattak, Muhammad Umer Farooq, John Cecava, Curtis L. Walker
Research On Weather Conditions And Their Relationship To Crashes, Mark R. Anderson, Aemal Khattak, Muhammad Umer Farooq, John Cecava, Curtis L. Walker
Nebraska Department of Transportation: Research Reports
The objectives of the research were to conduct a seasonal investigation of when winter weather conditions are a factor in crashes reported in Nebraska, to perform statistical analyses on Nebraska crash and meteorological data and identify weather conditions causing the significant safety concerns, and to investigate whether knowing the snowfall amount and/or storm intensity/severity could be a precursor to the number and severity of crashes.
Nebraska Department of Transportation (NDOT) crash data were combined with meteorological data on winter weather season basis, reported road surface condition at crash time, and reported weather conditions at crash time. Overall, the key finding …
Nebraska Rail Crossing Safety Research, Aemal Khattak, Yashu Kang, Huiyuan Liu
Nebraska Rail Crossing Safety Research, Aemal Khattak, Yashu Kang, Huiyuan Liu
Nebraska Department of Transportation: Research Reports
The research objectives of this project were to update Nebraska Department of Transportation (NDOT) 1999 Nebraska Accident Prediction Model for Highway-Rail Grade Crossings (HRGCs) and to develop guidelines using Lancaster County Nebraska HRGCs for improving safety at urban gated HRGCs that are not designated quiet zones but are in the vicinity of quiet zone crossings.
FRA crash and HRGC inventory data were utilized for estimation of the new model after inventory information on 742 HRGCs was updated. HRGC crashes for 2008-2018 period were used for model estimation while 2019 HRGC crashes were used for model prediction validation. After consideration of …
To Automate Detecting, Quantifying And Mapping Of Delamination Via Arial Thermography, Ziqi Shen, Chongsheng Cheng, Ri Na, Zhexiong Shang
To Automate Detecting, Quantifying And Mapping Of Delamination Via Arial Thermography, Ziqi Shen, Chongsheng Cheng, Ri Na, Zhexiong Shang
Nebraska Department of Transportation: Research Reports
The goal of this project is to develop a UAV-based Arial thermographic method to detect and map the delamination on concrete bridge decks. Several image processing methods such as level-set and machine-learning were developed in this project. The developed method is high-efficient and low-cost and requires no-traffic-closure during the surveying process. The coring outcomes from four different concrete bride decks validated the performance of this developed method. The coring results suggested that this method outperformed several existing methods in detecting delamination in concrete bridge decks in terms of efficiency, accuracy, cost, and safety.
High-Mast Tower Foundation, Chungwook Sim, Chung R. Song, Brandon Kreiling, Jay Puckett
High-Mast Tower Foundation, Chungwook Sim, Chung R. Song, Brandon Kreiling, Jay Puckett
Nebraska Department of Transportation: Research Reports
High-Mast Tower (HMT) foundations have been traditionally designed and constructed using cast-in-place foundation with anchor bolts that are used to secure the tower to the foundation. This type of design requires a base plate that is welded to the tower shaft. The Nebraska Department of Transportation (NDOT) has recently experienced issues with stresses that this type of design presents at the anchor bolt/foundation or base plate/tower shaft interface. This issue in worst cases may lead to a premature failure due to high-cycle fatigue as one of the towers at Milford, Nebraska that fell down during a winter snow storm event …
Data Analysis Of Nebraska Pavements Containing Rap, Abdullah Azzam, Yong-Rak Kim, Mohammad Rahmani, Jiong Hu
Data Analysis Of Nebraska Pavements Containing Rap, Abdullah Azzam, Yong-Rak Kim, Mohammad Rahmani, Jiong Hu
Nebraska Department of Transportation: Research Reports
Nebraska has used reclaimed asphalt pavement (RAP) materials (in a range of 20-50%) over more than 10 years in pavement construction. Despite the immediate economic and environmental benefits it has been reported that incorporating RAP may reduce pavement durability and crack resistance. This study used NDOT’s database to investigate the effect of RAP amount on the overall behavior of pavement performance. Toward that end, we collected data of pavement performance, mixture design, traffic, and environment of a total 254 pavement projects constructed between 2009 and 2012. Using the data, several analyses (such as descriptive, inferential, and life cycle cost) were …
Preparing For A Driverless Future, Daniel P. Piatkowski, Santosh Pitla, Joe Luck, Josephine K. Hazelton
Preparing For A Driverless Future, Daniel P. Piatkowski, Santosh Pitla, Joe Luck, Josephine K. Hazelton
Nebraska Department of Transportation: Research Reports
Autonomous vehicles (AVs) are widely considered to be the future of surface transportation in the United States, but little is understood about how people will interact with these vehicles, what they will use them for, and how they will impact our roads. However, farmers have been interacting with some degree of AV technology, primarily auto-guidance, in Nebraska for at least the last 10 years. The research in Section 1 first utilizes in-depth qualitative interviews to understand farmers’ experiences with using highly automated technology in order to inform adoption and diffusion patterns of AVs. The findings in Section 1 lead to …
Investing In Bicycle Infrastructure To Spur Statewide Economic Growth Through Bicycle Tourism, Pedro Aguero Arroyo, Daniel P. Piatkowski, F. Alsaleem
Investing In Bicycle Infrastructure To Spur Statewide Economic Growth Through Bicycle Tourism, Pedro Aguero Arroyo, Daniel P. Piatkowski, F. Alsaleem
Nebraska Department of Transportation: Research Reports
Bicycle tourism is a growing industry that has been shown by prior studies to contribute significantly to the economy of numerous states. The economic benefits of recreational bicycling are not limited to the direct effects of the transactions of bicyclists in related industries, but also spillover effects such as the reduction of automobile activity and its associated costs to society, or the decrease of the costs of obesity and inactivity to the healthcare system. This study focuses on the former and provides a qualitative and quantitative analysis of the economic impacts derived from recreational bicycling expenditure, as well as an …
A Big Data Approach For Improving Nebraska Cycling Routes, Fadi Alsaleem, Ali Al-Ramini, Mohammad Ali Takallou, Daniel P. Piatkowski
A Big Data Approach For Improving Nebraska Cycling Routes, Fadi Alsaleem, Ali Al-Ramini, Mohammad Ali Takallou, Daniel P. Piatkowski
Nebraska Department of Transportation: Research Reports
More people are becoming interested in creating healthy lifestyle habits for themselves. It has been proved that cycling has several health benefits. Therefore, governments are planning towards more cycling-friendly infrastructures and environments. To understand the cycling activities in Nebraska, we analyze Strava data for the last three years, providing valuable insight into cycling activities for urban planning purposes.
We analyze commute and recreational cycling patterns varying between weekdays and weekends to identify peak hours. Moreover, we study the effect of weather on cycling activity patterns for the last three years. Also, we use the impact of the outside temperature as …
Utilizing Kryton Kim Technology In Bridge Deck And Rail Construction To Protect Against Chloride Ion Penetration, Mick Syslo, Wally Heyen, Lieska Halsey, David Hansen, Tim Kranson
Utilizing Kryton Kim Technology In Bridge Deck And Rail Construction To Protect Against Chloride Ion Penetration, Mick Syslo, Wally Heyen, Lieska Halsey, David Hansen, Tim Kranson
Nebraska Department of Transportation: Research Reports
No abstract provided.
Best Practices To Address Issues Of Excess Aggregate Dust In Nebraska, Jiong Hu, Yong-Rak Kim, Temirlan Barissov, Shaya Gholami, Julia Grasley
Best Practices To Address Issues Of Excess Aggregate Dust In Nebraska, Jiong Hu, Yong-Rak Kim, Temirlan Barissov, Shaya Gholami, Julia Grasley
Nebraska Department of Transportation: Research Reports
The negative impacts of an excessive amount of dust on concrete performance have been known and reported in different states. The extent and impact of dust on concrete performance, which depends not only on quantity but also on the nature of dust could be complicated. For example, clay coatings showed a more harmful impact on concrete performance compared with carbonates (limestone dust) or stone dust. While clays that weakly adhere to aggregate will be dispersed in the mixing water and could lead to the workability or air entrainment issues, clays that are strongly bonded to the aggregate surface will remain …
Feasibility And Implementation Of Balanced Mix Design In Nebraska, Gabriel Nsengiyumva, Yong-Rak Kim, Jiong Hu
Feasibility And Implementation Of Balanced Mix Design In Nebraska, Gabriel Nsengiyumva, Yong-Rak Kim, Jiong Hu
Nebraska Department of Transportation: Research Reports
Balanced mixture design is an alternative asphalt concrete design method that incorporates the performance of mixtures during the design. Balanced mixture design consists of performance test methods and performance criteria. Compared to the existing Superpave design method which mostly relies on volumetrics to design mixtures, balanced mixture design is more suited to account for performance improvements originating from reclaimed asphalt pavement and other foreign additives such as rejuvenators, warm- mix asphalt additives, polymers, and anti-stripping agents. This study investigated the feasibility of the implementation of balanced mixture design in Nebraska mixtures by exploring appropriate test methods (i.e., for fracture and …
Development And Testing Of A Bridge Rail For Low-Volume Roads, Scott K. Rosenbaugh, Jacob Delone, Ronald K. Faller, Robert W. Bielenberg
Development And Testing Of A Bridge Rail For Low-Volume Roads, Scott K. Rosenbaugh, Jacob Delone, Ronald K. Faller, Robert W. Bielenberg
Nebraska Department of Transportation: Research Reports
A new steel bridge rail was developed for use on low-volume bridges. The railing consisted 31-in. tall, 12-gauge Wbeam guardrail mounted on S3x5.7 posts, which were supported by steel square-tube sockets attached to the side of the bridge deck. The sockets were to be attached to the steel C-channel that is typically placed along the edges of rural bridge decks in the state of Nebraska. The bridge railing was developed for use on both 7-in. thick cast in place decks and 12-in. thick prestressed concrete beam slabs.
Various welded and bolted socket-to-channel attachment designs were evaluated through dynamic bogie testing …
Colloidal Silica: Cement Enhancing Admixture Product Evaluation, Lieska Halsey, David Hansen
Colloidal Silica: Cement Enhancing Admixture Product Evaluation, Lieska Halsey, David Hansen
Nebraska Department of Transportation: Research Reports
As Class F- fly ash (F-ash) becomes scarce, PCC engineers will look to other supplemental cementitious materials (SCM) to replace F-ash and its ASR mitigating properties. Colloidal silica (CS), or nano-silica, has been shown to mitigate ASR at certain replacement levels; however, CS cannot be a full replacement of F-ash. Engineers at the Nebraska Department of Transportation (NDOT) learned of CS from a presentation given by Intelligent Concrete, Inc. at the 2019 Nebraska Concrete Professionals Association Conference and decided to investigate the potential use of CS in NDOT concrete mix designs.
Evaluation Of Mixtures And Pavement Performance For Rehabilitation Methods, Mohammad Rahmani, Gabriel Nsengiyumva, Yong-Rak Kim, Jiong Hu
Evaluation Of Mixtures And Pavement Performance For Rehabilitation Methods, Mohammad Rahmani, Gabriel Nsengiyumva, Yong-Rak Kim, Jiong Hu
Nebraska Department of Transportation: Research Reports
Pavement rehabilitation practice involves milling an asphalt surface and placing a new layer. The incorporation of reclaimed asphalt pavement (RAP) mixtures brings cost savings and preserves the environment and natural resources. However, the use of recycled materials can compromise pavement performance, in particular, RAP can contribute to cracking because the mixtures with recycled materials become more brittle. In Nebraska, pavement rehabilitation has mostly been conducted by milling old 4-in. asphalt surface and placing a new 4-in. layer. Due to the potentially increased use of RAP mixtures for pavement rehabilitation, it is necessary to look into potential applications of RAP-induced overlay …
Supporting Bridge Management With Advanced Analysis And Machine Learning, Joshua Steelman, Francisco Garcia
Supporting Bridge Management With Advanced Analysis And Machine Learning, Joshua Steelman, Francisco Garcia
Nebraska Department of Transportation: Research Reports
A supplemental Artificial Neural Network (ANN)-based tool was developed to support the Nebraska Department of Transportation (NDOT) in optimizing bridge management investments when choosing between refined modeling, field testing, retrofitting, or bridge replacement. Load ratings typically increase by approximately 15% to 20% when using detailed finite element analysis (FEA) instead of AASHTO approximate analysis methods. The ANN tool is implemented in an Excel spreadsheet to accept ten input parameters readily available to NDOT engineers performing typical load ratings, and predicts FEA- equivalent critical girder distribution factors (GDFs), removing unnecessary conservativism from approximate AASHTO GDFs, potentially justifying load posting removal for …
Prototype System For Implementing The Ultrasonic Guided Wave Method On The Field, Ece Erdogmus, Eric Garcia, Michael Schuller, Ahmad Shoaib Amiri
Prototype System For Implementing The Ultrasonic Guided Wave Method On The Field, Ece Erdogmus, Eric Garcia, Michael Schuller, Ahmad Shoaib Amiri
Nebraska Department of Transportation: Research Reports
This report presents the latest improvements in a recently developed nondestructive testing (NDT) technique for early detection of various flaws such as corrosion, delamination, and concrete cracking in reinforced concrete (RC) bridge decks. The method, named Ultrasonic Guided Wave Leakage (UGWL) method by the developing authors, involves use of internal steel reinforcement (rebar) as a wave guide for transmitting ultrasonic waves through the system and the measurement of leaked energy at the surface of the concrete. This report builds upon the progress made in the previously published phases of the project (M029 and M066), and aims to further explore the …
Research On School Zone Safety, Aemal Khattak, Yashu Kang
Research On School Zone Safety, Aemal Khattak, Yashu Kang
Nebraska Department of Transportation: Research Reports
This research investigated different aspects of school zone safety including the effects of speed differentials on drivers’ speeds in active school zones, the effects of school and surrounding characteristics on drivers’ speeds in active school zones, and the safety benefits and costs associated with active school zones. The research team identified 18 schools in Nebraska for data collection that consisted of drivers’ speed data, school and surrounding characteristics, and 2014-2018 reported crash data. The 18 schools were categorized by the school zone speed limit differentials: 35 to 25 mph, 40 to 25 mph, 30 to 25 mph, and 35 to …
Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu
Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu
Nebraska Department of Transportation: Research Reports
Due to the relatively high cement content and low water-to-cement ratio (w/c) used, bridge deck concrete is prone to premature cracking. Internal curing has been found to greatly reduce the chance of premature cracking as well as concrete deterioration. This research project was intended to develop internally cured bridge deck concrete based on a local mix design in Nebraska. Four different lightweight fine aggregate (LWFA) as internal curing agents were evaluated, and their effects on fresh, mechanical, durability, and shrinkage properties of concrete were studied. To identify the most effective LWFA dosage for shrinkage reduction, different replacement rates of sand …
Correlation Analysis Of Mdss And Newins, Mark R. Anderson, Curtis L. Walker, Nancy Barnhardt, Nathan Rick, Cameron Wunderlin
Correlation Analysis Of Mdss And Newins, Mark R. Anderson, Curtis L. Walker, Nancy Barnhardt, Nathan Rick, Cameron Wunderlin
Nebraska Department of Transportation: Research Reports
Improving winter maintenance is a goal of most transportation agencies including the Nebraska Department of Transportation (NDOT). One approach is to develop a decision support system to aid in the winter maintenance recommendations. Iteris has developed a maintenance decision support system (MDSS) and has teamed up with NDOT to provide winter weather guidance for operations. This report investigates how well the MDSS functions for several routes across Nebraska for different storm systems. The analysis was performed from saved events within MDSS and compared to meteorological observations during different storm events, mainly Colorado or Alberta Clipper type storms that moved through …
Development And Implementation Of A Moving Nondestructive Evaluation Platform For Bridge Deck Inspection, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Brian Mazzeo, Spencer Guthrie
Development And Implementation Of A Moving Nondestructive Evaluation Platform For Bridge Deck Inspection, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Brian Mazzeo, Spencer Guthrie
Nebraska Department of Transportation: Research Reports
Degradation in concrete bridge decks is typically manifested as rebar corrosion, concrete delamination, and surface cracks. Nondestructive evaluation and testing (NDE/NDT) technologies have been increasingly used in concrete bridge deck evaluation to identify, localize, and quantify deterioration in bridge decks. Each NDE method has its advantages and limitations on the type of defect that can be detected. Therefore, combining multiple NDE technologies is needed in order to give comprehensive and reliable information about the bridge deck condition. For effective application of multiple NDE tests, we need to use automated positioning for each NDE to facilitate post-processing and data fusion of …
Improvement Of Low Traffic Volume Gravel Roads In Nebraska, Richard L. Wood, Yong-Rak Kim, Yijun Liao, Mohammad E. Mohammadi
Improvement Of Low Traffic Volume Gravel Roads In Nebraska, Richard L. Wood, Yong-Rak Kim, Yijun Liao, Mohammad E. Mohammadi
Nebraska Department of Transportation: Research Reports
In the state of Nebraska, over one-third of roadways are unpaved, and consequently require a significant amount of financial and operational resources to maintain their operation. Undesired behavior of surface gravel aggregates and the road surfaces can include rutting, corrugation, and ponding that may lead to reduced driving safety, speed or network efficiency, and fuel economy. This study evaluates the parameters that characterize the performance and condition of gravel roads overtime period related to various aggregate mix designs. The parameters, including width, slope, and crown profiles, are examples of performance criteria. As remote sensing technologies have advanced in the recent …
Synthesis Of Repair Practices Of Damaged Precast/Prestressed Concrete Girders, George Morcous, Richard L. Wood, Antony Mohsen Kamal Masoud Kodsy
Synthesis Of Repair Practices Of Damaged Precast/Prestressed Concrete Girders, George Morcous, Richard L. Wood, Antony Mohsen Kamal Masoud Kodsy
Nebraska Department of Transportation: Research Reports
Bridge girders are constantly subjected to various types of damage during their service life. There is currently limited knowledge or guidelines provided by the NDOT Bridge Office Policies and Procedures (BOPP) regarding the assessment and repair procedures of damaged precast/prestressed concrete girders. This report aims to develop a comprehensive repair manual for precast/prestressed concrete girders subjected to damage caused by over-height vehicular collision and damage located at the girder ends. Over-height vehicular collision damage typically occurs at the middle portion of the exterior girders and the primary concerns are focused on flexural deficiencies. Girder end damage can occur due to …
Early Detection Of Near-Surface Void Defects In Concrete Pavement Using Drone Based Thermography And Gpr Methods, Zhigang Shen, Ece Erdogmus, George Morcous, Chngsheng Cheng, Zhexiong Shang, Theresa Mccabe, Antony Mohsen Kamal Masoud Kodsy
Early Detection Of Near-Surface Void Defects In Concrete Pavement Using Drone Based Thermography And Gpr Methods, Zhigang Shen, Ece Erdogmus, George Morcous, Chngsheng Cheng, Zhexiong Shang, Theresa Mccabe, Antony Mohsen Kamal Masoud Kodsy
Nebraska Department of Transportation: Research Reports
The goal of this research is to evaluate the feasibility and the performance of using UAV-mounted infrared thermography (IRT) and ground penetration radar (GPR) to detect sub-surface voids caused by consolidation issues in concrete pavement. The motivation of the study is to identify the consolidation defects as early as the initial set of concrete to avoid having this problem in large pavement sections, which is costly and time consuming to repair. Using the two technologies in combination to detect subsurface voids in the concrete initial set stage is new and aims to take advantage of the strengths and minimize the …
Development Of An Ndt Tool For In-Situ Assessment Of Prestress Loss, Bibo Zhong, Jinying Zhu, George Morcous
Development Of An Ndt Tool For In-Situ Assessment Of Prestress Loss, Bibo Zhong, Jinying Zhu, George Morcous
Nebraska Department of Transportation: Research Reports
The research objective is to develop a non-destructive testing (NDT) method to evaluate the prestress loss in prestressed concrete bridge girders using ultrasonic waves. The work principle is based on acoustoelastic effect - ultrasonic wave velocity varies with stress level in prestressed concrete. A self-reference test setup was proposed to measure wave velocity in two orthogonal directions (prestress and unstressed directions) in the girder. This setup will be able to reduce effects of material variation and temperature change.
The concept was first validated on small concrete specimens (cylinders and beams) in laboratory. A signal analysis algorithm was developed to reliably …
Feasibility Study Of Development Of Ultra-High Performance Concrete (Uhpc) For Highway Bridge Applications In Nebraska, Flavia Ribeiro Furtado De Mendonca, Mostafa Abo El-Khier, George Morcous, Jiong Hu
Feasibility Study Of Development Of Ultra-High Performance Concrete (Uhpc) For Highway Bridge Applications In Nebraska, Flavia Ribeiro Furtado De Mendonca, Mostafa Abo El-Khier, George Morcous, Jiong Hu
Nebraska Department of Transportation: Research Reports
Ultra-high performance concrete (UHPC) is a new class of concrete that has superior mechanical, durability, and workability properties that far exceed those of conventional concrete. To achieve these properties, a specific mix design with a very dense internal structure, fiber reinforcement, and low water-to-binder ratio (w/b) is commonly used. The goal of this research is to develop a non-proprietary UHPC mix with constituent materials that are readily available in the state of Nebraska for bridge construction applications. In developing this mix, the particle packing model is used, and an experimental study of the impact of various design parameters on the …
Evaluation Of Tie-Bar Anchoring Methods: Non-Shrink Grout Vs. Epoxy, Wally Heyen, Lieska Halsey, Tim Krason, Brandon Varilek, David Hansen
Evaluation Of Tie-Bar Anchoring Methods: Non-Shrink Grout Vs. Epoxy, Wally Heyen, Lieska Halsey, Tim Krason, Brandon Varilek, David Hansen
Nebraska Department of Transportation: Research Reports
Tie bars are epoxy coated steel bars that connect the longitudinal joints in concrete pavement. Tie bars prevent faulting and joint separation between lanes Tie bars can be placed into the plastic concrete or inserted after curing by drilling and anchoring with epoxy or non-shrink grout. The specification for the tie bars requires the use of a No. 5 bar, 18 inches long and shall meet ASTM A775 / A775M [1], Section 1020.The Nebraska Department of Transportation “Standard Specifications for Highway Construction,” (Section 603.03) requires contractors to mechanically insert tie bars into the face of pavements during construction. Tie bars …
Influence Of Curing Conditions On Concrete Specimens (Cylinders) In Hot And Cold Weather In The Field, Wally Heyen, Lieska Halsey, Tim Krason, David Hansen
Influence Of Curing Conditions On Concrete Specimens (Cylinders) In Hot And Cold Weather In The Field, Wally Heyen, Lieska Halsey, Tim Krason, David Hansen
Nebraska Department of Transportation: Research Reports
No abstract provided.