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Full-Text Articles in Transportation Engineering

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 Jan 2020

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 Jan 2020

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 Jan 2020

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 Jan 2020

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 …


Long-Term Performance Evaluation Of Nudeck In Kearney East Bypass, George Morcous, Marc Maguire Dec 2019

Long-Term Performance Evaluation Of Nudeck In Kearney East Bypass, George Morcous, Marc Maguire

Nebraska Department of Transportation: Research Reports

The Kearney East Bypass bridge is the first project that implements the newly developed precast concrete deck system (known as 2nd generation NUDECK). The new system consists of full-depth full-width precast prestressed concrete deck panels that are 12 ft (3.66 m) long each. The panels have covered shear pockets at 4 ft (1.22 m) spacing on each girder line to host clustered shear connectors that are adjustable in height. Narrow unreinforced transverse joints are used to eliminate the need for deck overlay. Also, deck panels are post-tensioned in the longitudinal direction using a new post-tensioning system that eliminates the need …


Standard Design For Nebraska County Bridges, Chungwook Sim, Jiong Hu, Maher K. Tadros, Alexander Bleyhl, David Gee Dec 2019

Standard Design For Nebraska County Bridges, Chungwook Sim, Jiong Hu, Maher K. Tadros, Alexander Bleyhl, David Gee

Nebraska Department of Transportation: Research Reports

Many county-owned bridges in Nebraska need replacement due to their structural deficiency. Most of the bridges needing replacement are in the 40 to 60 ft range. This span range lacks a standard design that fits Nebraska county practices in terms of speed and simplicity of construction. The current systems being used are (a) Precast 1 by 2 ft planks which can span up to 30 ft, (b) Cast-in-place slab bridges which can span up to 50 ft but require extensive field formwork, concrete placing, and curing, and are best when constructed in three-span units, and (c) Inverted tees which can …


Precast Concrete Deck-To-Girder Connection Using Uhpc, George Morcous, Mostafa Abo El-Khier Dec 2019

Precast Concrete Deck-To-Girder Connection Using Uhpc, George Morcous, Mostafa Abo El-Khier

Nebraska Department of Transportation: Research Reports

The implementation of ultra-high-performance concrete (UHPC) in bridge construction has been growing rapidly in the last two decades due to its excellent mechanical properties, workability, and durability. This report presents a new UHPC connection between precast concrete deck panels and bridge girders that eliminates changes to the design and production of girder shear connectors commonly used in conventional cast-in-place concrete deck construction. In conventional construction, girder shear reinforcement or studs are extended into the cast-in-place concrete deck to transfer interface shear and create composite section. In the new connection, girder shear reinforcement or studs are kept underneath the deck panels, …


Development Of High-Performance Rapid Patching Materials For Pavement Repair, Gholami Shayan, Jiong Hu, Yong-Rak Kim Dec 2019

Development Of High-Performance Rapid Patching Materials For Pavement Repair, Gholami Shayan, Jiong Hu, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

Concrete pavements exhibiting severe distresses which require patching are commonly observed in the concrete pavement in Nebraska. Due to the requirements of opening pavement to traffic after placing the rapid patching materials, it is essential for that concrete to achieve high early strength. To ensure this, a high cement content and chloride-based accelerators are currently used in the Nebraska Department of Transportation (NDOT) Portland cement-based rapid-patching materials. Besides its associated high cost, high cement content tends to result in a less stable mix with high shrinkage, high heat of hydration, and high cracking potential. In addition, using chloride-based accelerators has …


Condition Assessment Of Bridge Decks With Asphalt Overlay, Sepehr Pashoutani, Jinying Zhu Dec 2019

Condition Assessment Of Bridge Decks With Asphalt Overlay, Sepehr Pashoutani, Jinying Zhu

Nebraska Department of Transportation: Research Reports

Ground penetrating RADAR (GPR) is a widely used nondestructive testing (NDT) method for bridge deck evaluation. However, the current GPR signal and data processing software and algorithms are not able to provide comprehensive information about bridge deck condition. Although the original objective of this research project was to develop GPR analysis algorithms for condition assessment of bridge decks with asphalt overlay, the scope of work has been expanded to concrete bridge decks with or without overlays.

In this study, the research team developed a complete GPR analysis procedure that includes the following components: 1) obtain zero-time for GPR reflection at …


Investigation Of Dsr Test Methods To Determine Binder Low Temperature Properties, Kommidi Santosh, Yong-Rak Kim Aug 2019

Investigation Of Dsr Test Methods To Determine Binder Low Temperature Properties, Kommidi Santosh, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

The low temperature rheology of bituminous binders is of great interest because low temperature cracking is one of the primary asphalt pavement failure modes observed in cold-climate places such as Nebraska. Low temperature binder characterization/grading has been primarily conducted using the bending beam rheometer (BBR), while the dynamic shear rheometer (DSR) can alternatively be used to characterize the low temperature properties of binders with the recent advancement of DSR equipment that can cover a wide range of testing temperatures. This study investigates alternative testing-analysis methods using the DSR to determine low temperature asphalt binder properties that have been measured by …


Performance Evaluation Of Inverted Tee (It) Bridge System, Garrett P. Martindale, Daniel Watson, Antony Mohsen Kamal Masoud Kodsy, Mostafa Abo El-Khier, Richard L. Wood, George Morcous Aug 2019

Performance Evaluation Of Inverted Tee (It) Bridge System, Garrett P. Martindale, Daniel Watson, Antony Mohsen Kamal Masoud Kodsy, Mostafa Abo El-Khier, Richard L. Wood, George Morcous

Nebraska Department of Transportation: Research Reports

The Inverted Tee (IT) girder bridge system was originally developed in 1996 by the University of Nebraska–Lincoln (UNL) researchers and Nebraska Department of Transportation (NDOT) engineers. This bridge system currently accounts for over 110 bridges in Nebraska used for both state highways and local county roads. Extensive longitudinal and transverse deck cracking have been observed and noted in numerous bridge inspection reports. Since the IT girder bridge system is relatively new, limited data and knowledge exist on its structural performance and behavior. This study evaluates the IT girder bridge system by conducting twenty field observations as well as recording accelerometer, …


Restricted Crossings On Rural Highways, John Sangster, Tim Adams Jun 2019

Restricted Crossings On Rural Highways, John Sangster, Tim Adams

Nebraska Department of Transportation: Research Reports

This study examines the potential for replacing the standard intersection design at two-way stop control (TWSC) and all- way stop control (AWSC) intersections along rural highways with a roundabout or a restricted crossing u-turn (RCUT) facility. The geometry of the RCUT design prohibits left and through movements from the side road, and provides a u-turn location downstream from the main crossing. This type of facility has been implemented for rural highways extensively in both Maryland and North Carolina, as well as in limited cases in many other states such as Minnesota and Missouri, with the potential to serve as a …


Asphalt Binder Laboratory Short-Term Aging, Hamzeh Haghshenas, Robert C. Rea May 2019

Asphalt Binder Laboratory Short-Term Aging, Hamzeh Haghshenas, Robert C. Rea

Nebraska Department of Transportation: Research Reports

The Rolling Thin Film Oven (RTFO) is widely used to simulate asphalt binder short-term aging. However, there is a general interest to improve the current short-term aging protocol especially for reducing the aging time. Besides, there are some doubts about the capability of RTFO in the simulation of aging of highly polymer modified asphalt binders which is mainly due to improper dispersion of such binders in the bottles during rotating and creeping of highly viscous binder out of the bottles during rotation. This work addresses the effect of time, temperature, airflow rate, and weight of asphalt binder on the laboratory …


Evaluation Of Nebraska’S Aggregate Reactivity By The Miniature Concrete Prism Test Method – Aashto T380, Lieska Halsey, Wally Heyen Jan 2019

Evaluation Of Nebraska’S Aggregate Reactivity By The Miniature Concrete Prism Test Method – Aashto T380, Lieska Halsey, Wally Heyen

Nebraska Department of Transportation: Research Reports

The evaluation of nine different aggregates shows the viability of the T380 test method as an alternative to the standard C1293 test method. The T380 assesses the Alkali-Silica Reaction potential of aggregates with the same reliability as C1293 and correlates well with the C1293 test method. Results are obtained within 56 days by T380 compared to 365 days required by C1293. The T380 method at 56 days appears to characterize the aggregate reactivity similarly to C1293 for all the aggregates evaluated in this study. Therefore, T380 will be part of the Department test method for approval of interground/blended cements along …


Effect Of Moisture Condition On Concrete Core Strengths, Wally Heyen, Lieska Halsey Jan 2019

Effect Of Moisture Condition On Concrete Core Strengths, Wally Heyen, Lieska Halsey

Nebraska Department of Transportation: Research Reports

The main purpose of this study was to determine if there would be any major differences between curing methods of cores taken for acceptance testing from a highway slab on a project. The comparison provided data to determine the effect of the moisture gradients created by these different curing treatments on core strength and core permeability. The strengths were measured of moist cured cores and sealed plastic bag cured cores from the day cores were obtained (14, 21 and 26 days) until they reached 28 days. Permeability was also measured at 26, 28 and 32 days. According to ASTM C42, …


Investigating The Interaction Of Ndot Hot-Pour Pcc Joint Sealant And Penetrating Concrete Sealers, Bruce Barrett, Dale Byre, Wally Heyen, Lieska Halsey, David Hansen Jan 2019

Investigating The Interaction Of Ndot Hot-Pour Pcc Joint Sealant And Penetrating Concrete Sealers, Bruce Barrett, Dale Byre, Wally Heyen, Lieska Halsey, David Hansen

Nebraska Department of Transportation: Research Reports

Based on the field observations on NE-83, PCS potentially impacts the bond between the concrete and hot-pour sealant after application. If penetrating sealers break the interfacial bond after application, concrete pavements could become compromised and subject to freeze-thaw damage, chloride attack, and other deleterious effects.

The results show that discoloration occurred when applying the five PCS products to the NE-3405 hot-pour sealed testing blocks. All three test methods of application; spraying, 1-min, and 5-min soaks, caused discoloration. The level of discoloration increased with the duration of contact with the PCS. Despite discoloration, none of the five PCS products caused de-bonding …


Research On High-Rap Asphalt Mixtures With Rejuvenators - Phase Ii, Hamzeh Haghshenas, Gabriel Nsengiyumva, Yong-Rak Kim, Kommidi Santosh, Soroosh Amelian Jan 2019

Research On High-Rap Asphalt Mixtures With Rejuvenators - Phase Ii, Hamzeh Haghshenas, Gabriel Nsengiyumva, Yong-Rak Kim, Kommidi Santosh, Soroosh Amelian

Nebraska Department of Transportation: Research Reports

A previous study by the authors have demonstrated effectiveness of three rejuvenators: R1 (triglyceride/fatty acid: agriculture-tech based), R2 (aromatic extract: petroleum-tech based), and R3 (tall oil: green-tech based) on rejuvenating properties of the aged binder. In that study, it was observed that the rejuvenators made high-RAP mixtures softer and more compliant, which may increase the rutting potential, while they simultaneously improve cracking resistance of the high-RAP materials. Research outcomes and findings from the previous study resulted in consequential research needs for more specific investigation of high-RAP mixtures with rejuvenators in order to achieve realistic implementation into future high-RAP paving projects …


Validation Of The Mechanical Rocker Test Method For Ice Melting Capacity (Mrt-Imc), Lieska Halsey, David Hansen Jan 2019

Validation Of The Mechanical Rocker Test Method For Ice Melting Capacity (Mrt-Imc), Lieska Halsey, David Hansen

Nebraska Department of Transportation: Research Reports

The anti-icing and deicing industry has interest in the development of an objective, repeatable test procedure for the evaluation and comparison of anti-icing and deicing products. Pursuant to this goal, the Nebraska Department of Transportation (NDOT) funded research at the University of Nebraska-Lincoln (UNL) to investigate methods for evaluating deicing products, beginning in 2011[1]. Researchers at UNL developed the procedure for the Mechanical Rocker Test for Ice Melting Capacity (MRT or MRT-IMC) in 2014[2].

From 2017-2019, NDOT evaluated the MRT-IMC procedure for validity and suitability as a standard test procedure for assessing deicer performance. NDOT also explored opportunities to improve …


Cpt-Based Pile Design, Chung R. Song, Seunghee Kim, Binyam Bekele, Jingtao Zhang, Alex Silvey Jan 2019

Cpt-Based Pile Design, Chung R. Song, Seunghee Kim, Binyam Bekele, Jingtao Zhang, Alex Silvey

Nebraska Department of Transportation: Research Reports

The geotechnical design of a pile foundation is concerned with the determination of the safe magnitude of an external load that the foundation can carry without jeopardizing the stability of the supported structure. In recent years, in-situ sounding tests are becoming a more attractive method to predict pile capacity due to the rapid development of testing instruments, improved understanding of their mechanics and interpretation, and cost efficiency. The cone penetration test (CPT) and its upgraded version, the piezocone penetration test (PCPT), are the most widely used in situ sounding tests to predict pile capacity. This research report compared eight CPT-based …


Data-Driven Development Of A Roadside Safety Marketing Campaign For Tree Removal – Phase I, Cody S. Stolle, Thomas Ammon, Chris M. Vargas, Ronald K. Faller, Karla A. Lechtenberg, Erin L. Urbank Jul 2018

Data-Driven Development Of A Roadside Safety Marketing Campaign For Tree Removal – Phase I, Cody S. Stolle, Thomas Ammon, Chris M. Vargas, Ronald K. Faller, Karla A. Lechtenberg, Erin L. Urbank

Nebraska Department of Transportation: Research Reports

Since the 1970s, tree crashes have been one of the most common and deadly fixed-object fatal crash types, resulting in more than 3,000 fatal crashes and 3,500 fatalities each year. While fatal tree crashes could be prevented by removing trees adjacent to the roadway, an extensive national tree removal project would be unnecessary, cost-prohibitive, and would experience significant political resistance.

The Midwest Pooled Fund Program jointly funded a research study to develop marketing methods and approaches which would focus on tree removal, replacement, or relocation in the most critical areas. Researchers conducted an extensive background investigation into tree crashes, other …


New Mixture Additives For Sustainable Bituminous Pavements, Gabriel Mukristu Nsengiyumva, Kommidi Santosh, Yong-Rak Kim, Helan Xu, Yiqi Yang May 2018

New Mixture Additives For Sustainable Bituminous Pavements, Gabriel Mukristu Nsengiyumva, Kommidi Santosh, Yong-Rak Kim, Helan Xu, Yiqi Yang

Nebraska Department of Transportation: Research Reports

In an effort to improve mechanical properties of asphalt concrete, an exploratory research using mixture additives was attempted. Two different types of additives on two material scales were used: asphalt concrete (AC) level and binder level. At the start of this study, the effect of natural cornhusk fibers on the resistance of two types of AC mixtures on cracking were tested for hot-mix asphalt (HMA) and cold-mix asphalt (CMA). The results showed slight improvements in cracking resistance in cornhusk reinforced HMA, and in the case of the CMA, marshal flow. Overall, based on the test results, cornhusk-reinforced HMA and CMA …


Mash Test No. 3-10 Of A Non-Proprietary, High-Tension, Cable Median Barrier For Use In 6h:1v V-Ditch (Test No. Mwp-9), Mojdeh Asadollahi Pajouh, Karla A. Lechtenberg, Ronald K. Faller, James C. Holloway, Robert W. Bielenberg, Scott K. Rosenbaugh Mar 2018

Mash Test No. 3-10 Of A Non-Proprietary, High-Tension, Cable Median Barrier For Use In 6h:1v V-Ditch (Test No. Mwp-9), Mojdeh Asadollahi Pajouh, Karla A. Lechtenberg, Ronald K. Faller, James C. Holloway, Robert W. Bielenberg, Scott K. Rosenbaugh

Nebraska Department of Transportation: Research Reports

The Midwest Pooled Fund Program has been developing a prototype design for a non-proprietary, high-tension, cable median barrier for use in a 6H:1V median V-ditch. This system incorporates four evenly spaced cables, Midwest Weak Posts (MWPs) spaced at 8 to 16 ft (2.4 to 4.9 m) intervals, and a bolted, tabbed bracket to attach the cables to each post. Full-scale crash testing was needed to evaluate the barrier’s safety performance. According to the Manual for Assessing Safety Hardware 2016 (MASH) testing matrix for cable barriers installed within a 6H:1V median V-ditch, a series of eight full-scale crash tests are required …


Phase Ii Evaluation Of Floor Pan Tearing For Cable Barrier Systems, Dylan T. Meyer, Mojdeh Asadollahi Pajouh, Karla A. Lechtenberg, Ronald K. Faller, Robert W. Bielenberg, James C. Holloway Mar 2018

Phase Ii Evaluation Of Floor Pan Tearing For Cable Barrier Systems, Dylan T. Meyer, Mojdeh Asadollahi Pajouh, Karla A. Lechtenberg, Ronald K. Faller, Robert W. Bielenberg, James C. Holloway

Nebraska Department of Transportation: Research Reports

The objective of this research effort was to mitigate the potential for floor pan tearing and penetration into the occupant compartment by modifying the posts utilized in a prototype cable barrier system. A series of dynamic component tests were conducted on the modified Midwest Weak Post (MWP). A bogie vehicle was equipped with a simulated floor pan designed to replicate the height, thickness, and strength of the floor pan of a Kia Rio. Two methods of post modification were investigated, including edge protection on the top of the MWP as well as weakening of the MWP at the ground line. …


Hot Applied Sealant Bond Test For Joints With Penetrating Sealers, Lieska Halsey Feb 2018

Hot Applied Sealant Bond Test For Joints With Penetrating Sealers, Lieska Halsey

Nebraska Department of Transportation: Research Reports

Recently a concern has been raised for hot applied sealant bond for joints with penetrating sealers. The objective of this study will be to determine if the bond between the sealant and the concrete is compromised by the sealer currently approved to be used in Nebraska. The expected results will be that the bond is not compromised and is serving for the expected joint service life.


Corrosive Strength Of Concrete Cylinders By Different Preparation Methods: Sulphur, Neoprene Pads And Grinding, Wally Heyen, Lieska Halsey, Tim Krason Feb 2018

Corrosive Strength Of Concrete Cylinders By Different Preparation Methods: Sulphur, Neoprene Pads And Grinding, Wally Heyen, Lieska Halsey, Tim Krason

Nebraska Department of Transportation: Research Reports

The purpose of this evaluation is to compare the effects of four types of cylinder preparation methods prior to compressive strength testing in accordance to ASTM C 39.


Engineering Standards In Highway Design Litigation, Michael Lewyn Jan 2018

Engineering Standards In Highway Design Litigation, Michael Lewyn

Scholarly Works

Highway engineers sometimes believe that if they redesign streets to improve pedestrian safety (for example, by introducing traffic calming techniques) they might be successfully sued for negligent design by motorists. This chapter suggests that in such situations, governments are likely to be protected by discretionary function immunity. In addition, the chapter discusses a variety of technical issues.


Winter Maintenance Of Akron Roadways, Kayla Hillegass Jan 2018

Winter Maintenance Of Akron Roadways, Kayla Hillegass

Williams Honors College, Honors Research Projects

The city of Akron experiences several hundred crashes each winter season due to winter road and weather conditions. The winter maintenance practices of the city follow a guide by the Salt Institute that uses a combination of plowing and salting to clear the roads. This paper provides an understanding of winter maintenance from its beginnings to present day and will discuss how certain practices came to be. Looking at three other cities across the United States with similar characteristics in size or snowfall amount show many similarities with a few new concepts that Akron can consider (e.g., better communication via …


Evaluation Of Opportunities And Challenges Of Using Inrix Data For Real-Time Performance Monitoring And Historical Trend Assessment, Anuj Sharma, Vesal Ahsani, Sandeep Rawat Dec 2017

Evaluation Of Opportunities And Challenges Of Using Inrix Data For Real-Time Performance Monitoring And Historical Trend Assessment, Anuj Sharma, Vesal Ahsani, Sandeep Rawat

Nebraska Department of Transportation: Research Reports

In recent years there has been a growing desire for the use of probe vehicle technology for congestion detection and general infrastructure performance assessment. Unlike costly traditional data collection by loop detectors, wide-area detection using probe-sourced traffic data is significantly different in terms of measurement technique, pricing, coverage, etc. This affects how the new technology is applied and used to solve current traffic problems such as traffic incident management and roadway performance assessment. This report summarizes the experiences and lessons learned while using probe data for traffic operations and safety management in the state of Nebraska and makes recommendations for …


Increased Span Length For The Mgs Long-Span Guardrail System Part Iii: Failure Analysis, Sagheer A. Ranjha, Robert W. Bielenberg, John D. Reid, Ronald K. Faller Sep 2017

Increased Span Length For The Mgs Long-Span Guardrail System Part Iii: Failure Analysis, Sagheer A. Ranjha, Robert W. Bielenberg, John D. Reid, Ronald K. Faller

Nebraska Department of Transportation: Research Reports

The objective of this research study was to review and analyze the system failure observed during crash testing of an increased span length for the MGS long-span guardrail system in test no. MGSLS-2. Test no. MGSLS-2 was a full-scale crash test conducted on the MGS long-span guardrail with a span length of 311⁄4 ft (9.5 m). This test utilized universal breakaway steel posts (UBSPs) adjacent to the long span in lieu of the controlled release terminal (CRT) wood posts used in previous long span systems.

An engineering analysis was undertaken to review the downstream end anchorage failure observed in test …


Evaluation Of Adjustable Continuity Joint Variations For Use In The Restore Barrier, Scott Rosenbaugh, Jennifer D. Schmidt, Ronald K. Faller, James C. Holloway Jun 2017

Evaluation Of Adjustable Continuity Joint Variations For Use In The Restore Barrier, Scott Rosenbaugh, Jennifer D. Schmidt, Ronald K. Faller, James C. Holloway

Nebraska Department of Transportation: Research Reports

During MASH TL-4 full-scale crash testing of the RESTORE barrier, concrete cracking and spalling was observed on the barrier beams that would likely require repairs or replacement. This study sought to evaluate joint design alternatives for use in the RESTORE barrier in order to limit the amount of system damage. Three variations of the Adjustable Continuity Joint (ACJ) were identified as potential modifications: 1) incorporating rubber bearing pads within the ACJ, 2) utilizing normal weight concrete instead of lightweight concrete, and 3) incorporating a steel end cap into the ends of the beam segments.

Four dynamic component tests were conducted …