Engineering Commons^™

Low-Cement Concrete Mixture For Bridge Decks And Rails, Soumitra Das, George Morcous Ph.D., Jiong Hu

Nebraska Department of Transportation: Research Reports

Right after construction, drying shrinkage of restrained concrete bridge decks and rails causes early-age cracking, insertion of water and chemicals, and corrosion of reinforcing steel that eventually leads to delamination and spalling of concrete. The main objective of this research is to control early-age shrinkage cracking by reducing cementitious material content in bridge deck and rail concrete mixtures. Several reduced cementitious materials concrete (RCMC) mixtures were developed by optimizing aggregate particle packing and conducting overall performance evaluation. This evaluation was carried out in three phases. The first phase investigated the feasibility of new RCMC mixtures by testing workability, compressive strength, …

Erosion Resistant Rock Shoulder, Chung R. Song, Richard L. Wood, Basil Abualshar, Mark O'Brien, Bashar Al-Nimri, Mitra Nasimi

Nebraska Department of Transportation: Research Reports

Highway shoulder rocks are exposed to continuous erosion force due to unexpected floodings caused by climate change. The evaluation methods of the erosion resistance of highway shoulder rocks are not currently well-developed. This study developed a new large-scale testing device, the University of Nebraska-Lincoln Erosion Testing Bed (UNLETB), which has the capability of testing the shoulder gravels. Different gradations were tested using UNLETB, and the results distinguished a high-resistant group and a low-resistant group. The low resistant group was treated with different binding agents: Ammonium Lignosulfonate (LIGNO10), Soybean Soap Stock, and DirtGlue. The treated samples showed better erosion resistance based …

Energy Dissipation Optimization For Circular Culverts, David M. Admiraal, Chi Zhang

Nebraska Department of Transportation: Research Reports

Two types of energy dissipation devices at circular culvert outlets were investigated: full-length weirs and staggered weirs. Related literature was reviewed; a model broken-back circular culvert and dissipation basin was built; instrumentation was installed to measure discharge, piezometric head, and velocities; and four sizes of full-length and staggered weirs were tested over a range of discharges and tailwaters. Weir heights ranged from D/8 to 4D/8, in which D was the culvert diameter. The two weir types were subjected to two styles of tests: (1) tests unaffected by tailwater and (2) tailwater-influenced tests. For tall full-length weirs (3D/8 and 4D/8), basin …

Truck Platooning Effects On Girder Bridges: Phase Ii-Service, Joshua Steelman, Jay Puckett, Daniel Linzell, Bowen Yang

Nebraska Department of Transportation: Research Reports

Truck platooning—wirelessly linking two or more trucks to travel in a closely spaced convoy—is federally promoted to save fuel, improve the environment, and improve traffic operations. Platooning places trucks much closer than current design codes anticipate. While this strategy can provide higher fuel efficiency, it also can potentially overload structures. Previous reliabilitybased studies (Steelman et al., 2021; Yang et al., 2021) have focused on the Strength I limit state and have shown that trucks can operate at weights exceeding standard legal load limits even with short headways at operating-level reliability. However, service limit states in the AASHTO LRFD Bridge Design …

Crashworthy Perforated Square Steel Tube (Psst) Mailbox Support – Phase I, Robert W. Bielenberg, Cody S. Stolle, Ronald K. Faller

Nebraska Department of Transportation: Research Reports

Federal requirements have made it mandatory that safe mailbox support systems be designed to yield or breakaway whenimpacted by a vehicle. The Nebraska Department of Transportation (NDOT) has previously used a non-proprietary, U-channel post mailbox support that was evaluated at the Midwest Roadside Safety Facility (MwRSF) in the 1980's. NDOT desires that the mailbox support be updated to meet MASH 2016 TL-3 safety performance criteria and be redesigned to use perforated square steel tubing (PSST) for the mailbox support post.

The objective of this research project is to develop a non-proprietary mailbox support using PSST support posts that is MASH …

Nebraska Balanced Mix Design – Phase I, Farzad Yazdipanah, Mahdieh Khedmati, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

Balanced mix design (BMD) is an alternative concept for designing asphalt mixtures that mainly focuses on performance of mixtures rather than only volumetric analysis. Using this concept, it would be possible to account for the incorporation of recycled asphalt mixtures, warm technology, polymers, rejuvenators, and other foreign additives, as well as external effective factors on the mix design such as environmental effects. This project sought to investigate performance-based methodologies for the asphalt mix design by taking a step to develop a preliminary Nebraska BMD framework. With that, selection of appropriate performance tests, finding a functional laboratory aging protocol, and defining …

Inventory, Operations, And Safety At Free Right-Turn Ramps, Aemal Khattak, Jonathon Camezind, Mm Shakui Haque

Nebraska Department of Transportation: Research Reports

This research focused on traffic safety and operational performance of rural, minor approach stop-controlled intersections with free right-turn (FRT) ramps. The objectives of the research were to:

• Create a statewide inventory of rural FRT ramp intersections and provide to the Nebraska Department of Transportation (NDOT),
• Using NDOT 10-year crash data, conduct statistical safety analysis of rural FRT intersections extending ¼-mile in each direction from the intersection,
• Study vehicular operations at rural intersections with and without FRT ramps including a comparison of vehicular conflicts, and
• Develop guidelines for operations and safety tradeoffs to assist with NDOT projects on maintaining similar locations, …

Feasibility Study: Application Of Steel Sheet-Piles For The Abutment Of Water-Crossing Bridges In Nebraska, Seunghee Kim, Jongwan Eun, Chung R. Song, Chungwook Sim, Hung Phi Van, Basil Abualshar, Ramin Ziaei Tabari

Nebraska Department of Transportation: Research Reports

The overall goal of this study is to investigate the anticipated performance of steel sheet-pile bridge abutments to encourage its wider application to not only new construction but also repair and replacement of existing water-crossing bridges in Nebraska. For this purpose, this study first reviewed several bridge cases with axially loaded sheet pile abutments, as well as previous in-depth studies related to the bearing capacity of sheet piles. Then, this study conducted the large-scale direct shear tests to better understand the interaction between sheet pile and soil. As a result, about four-fifths of the internal friction angle of fill sand …

Establishment Of Wildflower Islands To Enhance Roadside Health, Ecological Value, And Aesthetics Phase Ii, Jackson Ebbers, Heidi L. Hillhouse, John A. Guretsky, Thomas J. Weissling

Nebraska Department of Transportation: Research Reports

No abstract provided.

Performance Of High Early-Strength Materials Used In Concrete Bridge Repair, Zina Ebrahim, Fray F. Pozo-Lora, Zachary Benson, Mohammad Mastali, Marc Maguire, Jiong Hu

Nebraska Department of Transportation: Research Reports

High early-strength materials are widely used for rapid concrete patching projects to limit road closure time and traffic obstruction. This research investigated the field performance of multiple high early-strength materials used in maintenance projects across Nebraska. Data from high early-strength products included in the state’s approved product list were collected and compared to field performance. In addition, a survey was prepared and distributed to the surrounding states to understand standard practices related to appropriate specifications of these materials that can be later used to develop specifications for the utilization of high early strength materials in Nebraska based on experimental and …

Uhpc Decked I-Beam For Accelerated Bridge Construction, George Morcous, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

Ultra-High-Performance Concrete (UHPC) is an excellent material for bridge construction due to its exceptional durability and superior mechanical properties. Several Departments of Transportations (DOTs), including NDOT, have limited the use of UHPC in bridge construction to joints and connections between bridge components due to the relatively high materials cost of commercially UHPC products. Recently, NDOT has sponsored a research project to develop a non-proprietary UHPC using local materials to reduce materials cost and ensure its availability to local contractors and precast producers. The project was completed successfully and an economical UHPC mix that satisfied all workability, durability, and strength requirements …