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Long Term Performance Of Gravel Base Course Layers In Asphalt, Hani H. Titi, Mahmoud Dakwar, Mohammad Sooman, Habib Tabatabai Dec 2018

Long Term Performance Of Gravel Base Course Layers In Asphalt, Hani H. Titi, Mahmoud Dakwar, Mohammad Sooman, Habib Tabatabai

Civil and Environmental Engineering Faculty Articles

This research investigated the performance of base layer aggregates in HMA pavements using laboratory tests (standard compaction, particle size analysis, Atterberg Limits, sodium sulfate soundness, Micro-Deval abrasion, absorption, specific gravity, and soaked CBR) on existing base layer materials as well as pavement surface visual and automated distress surveys. The purpose of this research was to investigate potential degradation of aggregate bases, strength variations over time, and the likely causes for both. Analysis of laboratory and field test results indicated significant variability in the properties and characteristics of base layer aggregate materials in various pavement test sections. Based on the results …


Use Of Ultra-High-Performance Fiber-Reinforced Concrete (Uhp-Frc) For Fast And Sustainable Repair Of Pavements, Shih-Ho Chao Dec 2018

Use Of Ultra-High-Performance Fiber-Reinforced Concrete (Uhp-Frc) For Fast And Sustainable Repair Of Pavements, Shih-Ho Chao

Publications

This research presents a new methodology, which enables streets, roads, highways, bridges, and airfields to use an advanced fiber-reinforced concrete material, which can delay or prevent the deterioration of these transportation infrastructure when subjected to traffic and environmental loadings. The major problem of concrete is its considerable deterioration and limited service life due to its brittleness and limited durability. As a result, it requires frequent repair and eventual replacement, which consumes more natural resources. Ultra-high-performance fiber-reinforced concrete (UHP-FRC) introduces significant enhancement in the sustainability of concrete structures due to its dense microstructure and damage-tolerance characteristics. These characteristics can significantly reduce …


A Threshold To Utilize Guayule Resin As A New Binder In Flexible Pavement Industry, Ahmed Hemida, Magdy Abdelrahman Dec 2018

A Threshold To Utilize Guayule Resin As A New Binder In Flexible Pavement Industry, Ahmed Hemida, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study denotes a threshold to utilize Guayule Resin as a new bio-based binder or asphalt cement (AC) proportion, both with/out crumb rubber modifier (CRM), regarding solutions for environment, cost, and sustainability aspects. Via this research, 15 designated binders will be presented, all of them were tested as unaged and RTFO, whereas eight binders proceeded with PAV. Superpave was utilized to study their physical properties. Viscosity was examined upon some guayule-based binders with/out CRM, getting 114cP (at 135℃) for BGR, increased to about 3 times with 10%CRM (by weight of liquid binder) and about 7-8 times with 20%CRM. Comparisons among …


Evaluation Of The Performance And Cost-Effectiveness Of Engineered Cementitious Composites (Ecc) Produced From Region 6 Local Materials, Gabriel Andres Arce Amador, Tyson Rupnow, Marwa Hassan Oct 2018

Evaluation Of The Performance And Cost-Effectiveness Of Engineered Cementitious Composites (Ecc) Produced From Region 6 Local Materials, Gabriel Andres Arce Amador, Tyson Rupnow, Marwa Hassan

Publications

The project objective is to develop cost-effective Engineered Cementitious Composites (ECC) with locally available ingredients in Region 6 to address the deficiencies observed in ordinary concrete materials. The study explored the utilization of two types of river sands (coarse and fine), two types of PVA fibers (long and short), four levels of cement replacement with Class F fly ash, and the implementation of recycled crumb rubber in the performance of ECC materials. A total of 24 mix designs were prepared and evaluated in compression, tension, and bending to assess its mechanical properties. Furthermore, the cracking characteristics of the materials produced …


Understanding Asphalt Concrete Aging Using Nanoindentation, Hasan M. Faisal Jul 2018

Understanding Asphalt Concrete Aging Using Nanoindentation, Hasan M. Faisal

Civil Engineering ETDs

Asphalt concrete (AC) is created by mixing liquid asphalt binder with solid aggregates. When asphalt binder is mixed with aggregates, it creates a thin film (about 7-16 microns thick) around the aggregate surface. Fine aggregate (smaller than 0.075 mm size) get entrapped within the binder film or mixed with the binder, and create a phase called mastic. Both asphalt film and mastic play significant roles in aging of asphalt pavement. To this day, tests were performed mainly on the bulk liquid asphalt, but not on the film or mastic. In this study, for the first time, nanoindentation tests were done …


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 …


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.


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

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

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.


Effect Of Polypropylene Fiber Reinforcement On The Consolidation, Swell And Shrinkage Behavior Of Lime Blended Expansive Soil, Arif Ali Baig Moghal, Bhaskar C.S. Chittoori, B. Munwar Basha Jan 2018

Effect Of Polypropylene Fiber Reinforcement On The Consolidation, Swell And Shrinkage Behavior Of Lime Blended Expansive Soil, Arif Ali Baig Moghal, Bhaskar C.S. Chittoori, B. Munwar Basha

Civil Engineering Faculty Publications and Presentations

In this article, synthetic fibers in the presence of lime stabilization are proposed as an alternative to overcome the issues related to shrink-swell distress in expansive soils. Two types of synthetic fibers, Fiber Cast® (FC) and Fiber Mesh® (FM), were studied by conducting one dimensional fixed ring Oedometer swell-consolidation and bar linear shrinkage tests. Three dosages (0.2, 0.4 and 0.6% percent by weight of soil) and two lengths of the fibers (6 and 12 mm) were evaluated with and without lime treatments. The results indicated that FC fibers had better swell restricting performance in the absence of lime treatment, while …


Optimization For The Allocation Of Funds For Pavement Maintenance In Pavement Management Systems, Armando Ramirez Jan 2018

Optimization For The Allocation Of Funds For Pavement Maintenance In Pavement Management Systems, Armando Ramirez

Open Access Theses & Dissertations

Pavement maintenance and rehabilitation are critical and costly elements for highway agencies. A challenge for transportation agencies is to preserve roadways in an appropriate condition and extend the pavement service life while maintaining the safety and satisfaction of its users, and maximize the benefits obtained by the repair investments. Pavement maintenance programming is increasing in complexity due to limited resources and increments in traffic and population. Management decisions are usually based on personal judgment by pavement managers and sometimes those decisions are not even supported by previous experience. Research shows that optimization methods can produce significant benefits when transportation agencies …


Guayule Plant Extracts As Binder Modifiers In Flexible (Asphalt) Pavement Mixtures, Steven Michael Lusher Jan 2018

Guayule Plant Extracts As Binder Modifiers In Flexible (Asphalt) Pavement Mixtures, Steven Michael Lusher

Doctoral Dissertations

"The guayule (pronounced, 'why-YOO-lee') plant is a woody perennial shrub that is native to areas of the southwestern United States and northern Mexico, and is a well-documented source of high-quality natural rubber. The U.S. needs a domestic source of natural rubber to allay concerns about its future availability. Cultivation of guayule in North America has been attempted many times since the late 19th century, and companies, including major tire manufacturers, are again investing in guayule research. However, full-scale commercialization of guayule rubber needs established markets for the two basic by-products of guayule rubber extraction: the plant resins (primarily non-rubber compounds) …