Engineering Commons^™

Effect Of Antioxidant Additives And Recycling Agents On Performance Of Asphalt Binders And Mixtures - Phase I, Nitish R. Bastola, Mahdieh Khedmati, Hamzeh Haghshenas, Jamilla Teixeira

Nebraska Department of Transportation: Research Reports

The use of reclaimed asphalt pavement (RAP) in asphalt mixtures has notably increased in recent times. Nevertheless, the inherent stiff and aged characteristics of RAP materials have consistently raised concerns regarding cracking performance. The use of recycling agents (RAs) has gained popularity in recent years since they can effectively modify the engineering properties of the aged asphalt binder. Besides that, the combination of RA with antioxidant (AO) additives has shown promise in enhancing the long-term performance of RAP mixtures. This research aims to investigate the effect of various RAs and one AO additive on performance of asphalt binders and high-RAP …

Laboratory Evaluation Of The Residue Of Rubber-Modified Emulsified Asphalt, Dongdong Ge, Xiaodong Zhou, Siyu Chen, Dongzhao Jin, Zhanping You

Michigan Tech Publications

Emulsified asphalt has been widely used in various surface treatment methods such as chip seal for low-volume road preservation. Using modified emulsified asphalt made it possible to use chip seal technology on medium-and even high-volume traffic pavements. The main objective of the study is to quantify the residue characteristics of rubber-modified emulsified asphalt and to assess the effectiveness of using crumb rubber to modify emulsified asphalt binder. The four emulsified asphalt residues used the distillation procedure. Then, the rheology characteristics of emulsified asphalt residue were evaluated. The Fourier transform infrared spectroscopy (FTIR) test analyzed the chemical change of emulsified asphalt …

Agenator: An Open Source Computer-Controlled Dry Aging System For Beef, Soon Kiat Lau, Felipe Azevedo Ribeiro, Jeyamkondan Subbiah, Chris R. Calkins

Department of Biological Systems Engineering: Papers and Publications

Dry aging of beef is a process where beef is exposed to a controlled environment with the ultimate goal of drying the beef to improve its quality and value. Comprehensive investigations into the effects of various environmental conditions on dry aging are crucial for understanding and optimizing the process, but the lack of affordable equipment focused on data collection makes it difficult to do so. The Agenator was thus developed as an open source system with a suite of features for investigating dry aging such as: measuring and recording relative humidity, temperature, mass, air velocity, and fan rotational speed; precise …

Viscoelastic Analysis And Fatigue Characterization Of Bituminous Materials In Two Length Scales Under The Influence Of Aging, Santosh Reddy Kommidi

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Fatigue cracking in asphalt concrete (AC) is of immense importance to pavement design and analysis because it is one of the most important forms of distress that can lead to structural failure in pavement. Once started, these types of cracks can be combined with other environmental factors leading to detrimental effects such as faster rates of pavement deterioration and shortened pavement life and functionality.

Currently AASHTO TP101, also known as linear amplitude sweep (LAS) specification, is being widely used to evaluate the ability of an asphalt binder to resist fatigue. The LAS method, although mechanistic in its approach, has certain …

Evaluation Of Durability And Homogeneity Of Rejuvenated Asphalt Binders, Mojtaba Mohammadafzali

FIU Electronic Theses and Dissertations

Despite the widespread recycling of Reclaimed Asphalt Pavement (RAP), a large portion of it is still wasted. One of the main reasons is the concern with the performance of high RAP mixtures. Asphalt binder aging and subsequent rejuvenation is one source of uncertainty. Rejuvenators are frequently added to high RAP mixes to enhance the properties of the binder. This enhancement is often perceived as simply lowering the viscosity. Two important parameters that are not adequately addressed by existing methods are durability and homogeneity of the recycled binder. This research investigated these two concerns and provided quantitative indicators to measure them. …

Optimizing Chemical & Rheological Properties Of Rejuvenated Bitumen, Dominic Nguyen, Hamzeh Haghshenas Fatmehsari, Santosh Kommidi, Yong-Rak Kim

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Bitumen has long been a material used in the construction of roadways, yet new pavement only consists of low fractions of recycled materials due to poor compatibility of aged bitumen and new materials. Thus, rejuvenators, chemical additives, have been used in an attempt to re-balance the chemical composition and restore the physical properties of aged bitumen back to its virgin state. A fundamental understanding of how one particular rejuvenator, soybean oil, revitalizes bitumen was investigated using a multi-scale approach.

Fourier-transform infrared spectroscopy (FTIR) was used to determine the changes in chemical properties of pure and rejuvenated virgin and aged samples. …

Second Phase Study Of Changes In In-Service Asphalt (Vol 1: Main Report), Khaled A. Galal, Thomas D. White, Adam J. Hand

JTRP Technical Reports

In response to the need to improve asphalt pavement performance, the Strategic Highway Research Program (SHRP) was initiated in 1987. Products from SHRP included performance-based specifications for asphalt binders and performance-based mix design tests and criteria for asphalt mixtures. The Superpave asphalt binder specification addresses performance of in-service pavements for given environmental and traffic conditions. During the 1985 paving season in Indiana, the original asphalt binder and HMA (truck mix samples) from a number of pavements were sampled and retained. Cores were also taken from these pavements after seven or eight years of service. Condition surveys were performed on these …

The Effects Of Bag House Fines And Incomplete Combustion Products In A Drum Drier On The Characteristics Of Asphalt Paving Mixtures, Phase Ii, Jyh-Dong Lin, Leonard E. Wood

JTRP Technical Reports

An extensive laboratory study of the asphalt paving mixtures containing baghouse fines has been conducted through seven sets of experimental designs to characterize the performance of pavement. Marshall size specimens of asphalt paving mixtures with different kinds and amounts of baghouse fines were fabricated using the gyratory testing machine. The following techniques were used to evaluate the influence of the various variables upon mechanical properties such as: gyratory parameters, resilient modulus, indirect tensile strength, indirect creep, and Hveem stability tests to evaluate their mechanical properties. In addition, in the asphalt paving mixtures, asphalt cement was replaced with baghouse fines in …