Civil Engineering Commons^™

Impact Of Clay Contamination On Rutting Performance Of Asphalt Mixes, Sharmila Afsha

Open Access Theses & Dissertations

Sustainability of asphalt mixtures can be improved by using natural sands. They can enhance workability and lower the amounts required for asphalt binder and manufactured fine aggregate of mixes. However, one of the primary concerns with incorporating natural sands in a mixture is clay contamination. Harmful clays are chemically active particles that swell when exposed to moisture and reduce the bond between aggregate and asphalt binder. As a result, this study explores the effect of clay contamination on the rutting and moisture susceptibility of asphalt mixes. Twenty-one clay combinations of material passing the 0.075 mm (#200) sieve were selected utilizing …

Effect Of Impurities In Plastic Waste On The Performance Of Plastic Road, Niloy Gupta

Civil Engineering Dissertations

Plastic waste generation has become a global concern, with a large portion of plastics ending up in landfills. China's recent decision to stop importing waste from various countries, including the USA, has exacerbated the issue of plastic pollution. These plastics, as coming from the household and commercial trash, contain impurity and contamination. This makes the recycling process of plastics more hectic and causes issues in reusing them for other purposes. Impurity and contamination, in fact, is a major issue in material science. Researchers have been studying ways to improve the performance of bituminous pavement, as highways are experiencing increased demand …

Design Of Crack Attenuating Mix Using Waste Plastic, Shruti Singh

Civil Engineering Dissertations

Plastic has many good properties such as inexpensiveness, light weightedness and durability, but it comes with one major catch i.e., its ‘indestructibility’. Plastic waste is now omnipresent and highlights that all plastic ever produced still exists in some shape or form either as macro, micro or nano plastics, making it one of the greatest challenges our planet is facing today. At the same time many existing pavements are experiencing structural and functional deficiencies due to rapid growth in traffic volume. This has led to an ever-increasing rise in construction and rehabilitation cost. So, an alternative has been explored through this …

Evaluation Of Surface Asphalt Mixes Containing Recycled Asphalt Materials In North-East Texas Using Accelerated Pavement Testing, Ana Maria Coca

Civil Engineering Dissertations

Reclaimed asphalt pavement (RAP) and Reclaimed Asphalt Shingles (RAS) has proved to be an effective alternative to virgin materials in HMA production. Despite that recycling asphalt creates a cycle that optimizes the use of natural resources and sustains the pavement industry, State transportation departments have limited the maximum amount of RAP used in surface layers because of the variability concerns and lack of guidance provided. Even though at the moment, the United Stated recycles more RAP than Europe does in terms of percentage of the total RAP extracted from old pavements, it still lags Japan and other countries. A special …

Reuse Of Recycled Plastic For Plastic Road Design, Tahsina Islam

Civil Engineering Dissertations

The ever-increasing volume of traffic and the volatility of daily and seasonal temperatures that are being experienced globally make it essential that the quality and durability of roads are improved. Modifiers can improve the engineering properties of the asphalt mix in these situations. Perhaps plastics are the most promising of all types of modifiers. Since the disposal of plastic waste is a major concern for the environment, recycling of these waste materials is highly desired. The recycling and reuse of plastic waste is a prime example of sustainable waste management. It reduces the buildup of waste in landfills, thereby reducing …

Harmonizing Asphalt Mix Selection With Pavement Structural Design, Mahdi Saghafi

Open Access Theses & Dissertations

The state-of-the-practice in asphalt concrete (AC) mix design and pavement structural design are based on two divergent concepts. The laboratory tests that are used for mix design, especially under the balanced mix design concept, are pragmatically accelerated surrogate tests developed to ensure the stability or ranking of mixes. Pavement structural design methods, being empirical or mechanistic, ignore these laboratory test results, in favor of other mechanical parameters. As such, the selection of the type of mix to be placed on a project is based on the local experience, and a set of consensus limits, rather than the demand of the …

Variability In The Hamburg Wheel-Tracking Device (Hwtd) Data And Results, Ilerioluwa S. Giwa

LSU Master's Theses

Over the years, the Hamburg Wheel-Tracking Test (HWTT) has become one of the most popular devices used for characterizing asphalt mixtures for rutting potential and moisture susceptibility. However, although the HWTT is a reliable standard test for evaluating asphalt mixtures, it is not exempt from variability in the test data and result. Variability in the HWTT test data and results have been majorly attributed to imprecision in the test practice and due to some limitations in the HWT device setup.

The primary goal of this study is to evaluate the variability in the HWTT data and result by investigating a …

New Generation Of Performance-Engineered Asphalt Mixtures Based On Balanced Mix Design Concept, Victor Manuel Garcia

Open Access Theses & Dissertations

Asphalt mixtures must ideally exhibit long-lasting durability and stability to perform wellin the field. However, improving the stability and durability of asphalt mixtures has become a major concern. Given that available design approaches rely mainly on stringent volumetric criteria for asphalt mixtures, design approaches and specifications that incorporate performance tests are needed to follow a performance-engineered mix design (PEMD) process, especially with the introduction of the balanced mix design (BMD) concept

This Dissertation study presents a comprehensive investigation of a feasible designapproach that can be implemented to develop PEMD specifications and produce BMD mixtures. An experimental evaluation of different mix …

Enhancements Of Shear Tests For Asphalt Concrete, Yazeed Suleiman Jweihan

Civil Engineering Dissertations

The measurement of the fundamental shear properties of asphalt mixes is imperative to the improvement of modelling of rutting development in asphalt concrete. The Duplicate Shear Tester (DST) is a recent device developed at the University of Texas at Arlington as a replacement to the Superpave Shear Tester (SST). It measures the average shear properties of two asphalt concrete specimens at the same time. It has ability to perform the two common SST tests: the FSCH and RSCH in according to the standard test method AASHTO T-320. Although the DST has successfully satisfied the objectives of being a reliable, inexpensive …

Treated Versus Untreated Aggregate Bases For Flexible Pavements: A Nationwide Comparitive Study, Hemant Gc, Mena I. Souliman

Civil Engineering Theses

Aggregates are a major part of highway construction and its quality as well as strength affects the overall performance of the pavement structure. The base material near the construction site does not always meet the strength requirement needed for the pavement construction and the hauling of quality aggregate increases the construction costs. For better use of local available materials, stabilizing agents such as lime and asphalt cement have been utilized to increase the strength of crushed aggregate bases. Performance of pavement structures is heavily influenced by the thickness of the structure as well as material properties of each layer. The …

Mechanistic Analysis And Economic Benefits Of Fiber-Reinforced Asphalt Mixtures, Ashish Tripathi

Civil Engineering Theses

Fatigue cracking and permanent deformation (rutting) are major distresses that occur in flexible pavements. Four-point bending beam as well as flow number laboratory tests have been used for several decades to evaluate the long-term fatigue and rutting resistance for asphalt mixture, respectively. One of the most significant solutions to prolong the fatigue life and improve rutting resistance for an asphaltic mixture is to utilize flexible materials such as fibers. In 2008 a laboratory testing program was performed on a conventional and fiber-reinforced mixtures to investigate the impact of added fibers on the mechanical, mechanistic, and economical attributes of asphaltic mixtures. …

Influence Of Mix Design Parameters On Performance Of Balanced Asphalt Mixtures, Luiza Helena Barros

Open Access Theses & Dissertations

With the popularity of the Balanced Mix Design (BMD) concept, the need for performance tests that can reliably evaluate the cracking and rutting potentials of asphalt concrete (AC) mixes has become more critical. A great deal of effort has been focused on incorporating test methods that can potentially improve the current AC mix-design processes and consequently screen underperforming AC mixes. However, the influence of mix design parameters on the performanceof BMD mixes that provide pavement engineers and designers with thorough guidelines and a reliable and consistent test protocol has not been extensively documented.

This Thesis presents an experimental evaluation of …

Improvements To The Duplicate Shear Tester, Yazeed Suleiman Jweihan

Civil Engineering Theses

Rutting in the asphalt concrete layer is a major distress in flexible pavements caused by the permanent shear deformation in asphalt mixes. The shear deformation is induced by heavy truck axis during hot summer days. Rutting affects directly the safety and users comfort. Therefore, developing of an appropriate test device for measuring the fundamental shear properties of asphalt mixes is important in order to improve the rutting resistance of asphalt mixes and pavement performance. The desired device should be simple, inexpensive, and accurate to be able to be incorporated for a quality control or quality assurance process, as well as …

Rheological Study Of Asphalt Binders With A Wax-Based Warm Mix Additive And Its Relationships To Mix Compaction And Rutting, Rajan Saha

Doctoral Dissertations

Although the energy saving Warm Mix Asphalt (WMA) technology that produces asphalt mixes at lower temperatures are around for about a decade, there still exist some concerns that are hindering its wide spread implementation. The overall objective of this study is to investigate if the viscosity reductions at higher temperatures have any impacts on asphalt mix compaction and rutting performances. This study reveals that there exists a critical temperature for each asphalt binder below which viscosity will increase with addition of Sasobit®. Therefore, compaction below the critical temperature can negatively impact density.

For PG 64-22, the critical temperature is 104 …

The Effects Of Fundamental Mixture Parameters On Hot-Mix Asphalt Performance Properties, Wenbin Zhao

All Dissertations

Asphalt pavements are composed of three components: aggregate, asphalt binder, and air. In the process of plant production and on-site construction, the construction quality can vary in the three component and the variability can further affect a pavement's future performance.. This research identifies aggregate gradation, binder content, and air voids content as the fundamental parameters. Understanding the fundamental parameters' influence on the HMA mixture's performance properties can provide valuable information on how to improve the current quality insurance practice. The objective of this study is to conduct well-controlled experiments to investigate how mix gradation, air voids and small range binder …

Integrated Finite Element Analysis Program To Evaluate Pavement Performance And Predict Non-Destructive Testing Response, Cesar Tirado

Open Access Theses & Dissertations

The response of a pavement system under wheel loading has been a subject of research for many decades. Several models have been developed to predict pavement performance based on layer deformation and fatigue cracking. Among them stand out computer programs based on linear elasto-static layered systems and viscoelastic-plastic models; however, newer or more advanced constitutive models cannot be rigorously incorporated into them. In contrast, finite element techniques allow incorporation of nonlinear and viscoelastic-plastic behavior of the pavement materials but licensing of software and the need to train personnel greatly limits its use by highway agencies. A mechanistic-empirical (M-E) approach for …

Comparative Performance Of Rubberized Hot Mix Asphalt Under Alf Loading, Hanlin Qin

Doctoral Dissertations

In response to the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, Louisiana constructed five projects to evaluate several methods of using discarded tire rubber in highway pavements. The field performance was quite variable. To achieve the agreement among state agencies on the engineering benefits of using crumb rubber modifier (CRM) in HMA pavement and to define the circumstances where the LaDOTD can use asphalt rubber materials in the most cost effective way, a full-scale research program has been conducted at the Louisiana Transportation Research Center (LTRC) to evaluate the performance of CRM-HMA asphalt pavement under Accelerated Loading Facilities (ALF). …