Engineering Commons^™

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 …

Research On High-Rap Mixtures With Rejuvenator - Field Implementation, Nitish R. Bastola, Mahdieh Khedmati, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

The use of Rejuvenating Agents (RAs), as Recycled Asphalt Pavement (RAP) modifiers, has been increasing over the past years. However, the field performance of asphalt mixtures containing high-RAP materials and modified with RAs has raised some concerns regarding the long-term performance of RAs. This study evaluated the laboratory and field performance of high-RAP mixtures with and without bio-oil RA. Three sets of plant-produced specimens were collected: 1) laboratory-compacted; 2) field-compacted and cored after paving; and 3) field-compacted and cored after one and two years. The Hamburg Wheel Tracking (HWT) test was used to evaluate the specimens' resistance to rutting and …

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

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 …

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 …

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 …

Evaluation Of Tack Coating Practices For Asphalt Overlays In Nebraska, Soroosh Amelian, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

The strength of the bond between asphalt layers affects the lifespan of pavement structures. It is also a key factor in preventing major pavement distresses, such as slippage cracking and delamination. This research project evaluates and compares the effectiveness and performance of different tack coating approaches to ensure the proper bond strength is achieved in asphalt concrete (AC) interlayers through an experimental study. Various tack coat materials, including different types of emulsified asphalt and asphalt binders, at multiple application rates and dilution ratios were investigated. In the first part of this study, laboratory-prepared samples were used to evaluate the sensitivity …

Research On High-Rap Asphalt Mixtures With Rejuvenators And Wma Additives, Hamzeh Haghshenas, Hesanaddin Nabizadeh, Yong-Rak Kim, Kommidi Santosh

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of A Semicircular Bend (Scb) Test Method For Performance Testing Of Nebraska Asphalt Mixtures, Gabriel Nsengiyumva, Yong-Rak Kim, Taesun You

Nebraska Department of Transportation: Research Reports

No abstract provided.

Evaluation Of Thin Asphalt Overlay Practice Preserving Nebraska's Asphalt Pavement, Soohyok Im, Yong-Rak Kim, Hamzeh Haghshenas Fatmehsari, Gabriel Nsengiyumva, Taesun You

Nebraska Department of Transportation: Research Reports

No abstract provided.

Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Yong-Rak Kim, Thaddaeus Bode

Nebraska Department of Transportation: Research Reports

This research was conducted to study more realistic explanations of how variables are created and dealt with during hot mix asphalt (HMA) paving construction. Several paving projects across the state of Nebraska have been visited where sensory devices were used to test how the selected variables contribute to temperature differentials including density, moisture content within the asphalt, material surface temperature, internal temperature, wind speed, haul time, and equipment type. Areas of high temperature differentials are identified using an infrared camera whose usefulness was initially confirmed with a penetrating thermometer. A non-nuclear density device was also used to record how the …

Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Thaddaeus Bode, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

No abstract provided.

Moisture Sensitivity Of Hot Mix Asphalt Mixtures In Nebraska -- Phase Ii, Ingryd Pinto, Hoki Ban, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

No abstract provided.

Moisture Sensitivity Of Hot Mix Asphalt (Hma) Mixtures In Nebraska – Phase Ii, Yong-Rak Kim, Hoki Ban, Ingryd Pinto

Mid-America Transportation Center: Final Reports and Technical Briefs

As a consequential effort to the previous NDOR research project (P564) on moisture damage, this report presents outcomes from this project incorporated with the previous project. Performance changes and fundamental material characteristics associated with moisture damage due to various anti-stripping additives in asphalt mixtures are studied through various experimental approaches and a numerical simulation. Three additives (i.e., one reference additive, hydrated lime, and two alternative additives: fly ash and cement) are investigated by adding them into two types of mixes (SP2 for low-traffic-volume roadways and SP5 for high-traffic-volume roadways) where two different asphalt binders (PG 64-22 for the SP2 mix …

A Performance-Based Incentive Program For Asphalt Pavement, Tim Wentz, Satya Peruri, Wayne Jensen, Bruce Fischer

Nebraska Department of Transportation: Research Reports

No abstract provided.

Material Selection And Design Consideration For Moisture Damage Of Asphalt Pavement, Jamilla Emi Sudo Lutif, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

No abstract provided.