Implementation of a Hybrid Teaching Environment for a Traffic Engineering Course

Students learn in different styles. They learn via hearing and visualizing. They can also reflect and act upon what is presented to them. Afterwards, they start to reason in a logical and intuitive ways as well as memorizing and visualizing, and eventually building mathematical models. Teaching approaches also differ from one course to another and from one instructor to another. Some instructors tend to lecture, others demonstrate or discus while some focus on principles and applications. The quality of student learning process is controlled by the student’s own ability and previous preparation but it also depends on the affinity of the student’s learning style and the instructor’s teaching delivery style. This case study illustrates the transition of a four-thousand level traffic engineering course from a pure face-to-face to a hybrid environment. The implemented hybrid teaching style included one face-to-face weekly lecture besides another lecture being posted online as a YouTube video. Analytical comparisons were conducted between two offerings of the course: before and after the hybrid teaching style Implementation. Based on the presented results, including improved overall grades, student enrollment increase, and positive evaluation feedback, it can be concluded that the implementation process was successful.Cockrell School of Engineerin

Prediction of average annual surface temperature for both flexible and rigid pavements

The surface temperature of pavements is a critical attribute during pavement design. Surface temperature must be measured at locations of interest based on time-consuming field tests. The key idea of this study is to develop a temperature profile model to predict the surface temperature of flexible and rigid pavements based on weather parameters. Determination of surface temperature with traditional techniques and sensors are replaced by a newly developed method. The method includes the development of a regression model to predict the average annual surface temperature based on weather parameters such as ambient air temperature, relative humidity, wind speed, and precipitation. Detailed information about temperature and other parameters are extracted from the Federal Highway Administration's (FHWA) Long Term Pavement Performance (LTPP) online database. The study was conducted on 61 pavement sections in the state of Alabama for a 10-year period. The developed model would predict the average annual surface temperature based on the known weather parameters. The predicted surface temperature model for asphalt pavements was very reliable and can be utilized while designing a pavement. The study was also conducted on seven rigid pavement sections in Alabama to predict their surface temperature, in which a successful model was developed. The outcome of this study would help the transportation agencies by saving time and effort invested in expensive field tests to measure the surface temperature of pavements

City of Tyler Hub-and-Spoke Bicycle Lane Network

4th Annual Lyceum at The University of Texas at Tyler.https://scholarworks.uttyler.edu/student_posters/1036/thumbnail.jp

3-D Move Mechanistic Analysis and Cost Effectiveness of Asphalt Rubber and Polymer Modified Asphalt Pavement Under Various Axle Loading Conditions

A variety of axle loading conditions can lead to different tensile strains in asphalt pavements. One way to increase resistance to these tensile strains is to add materials such as crumb rubber or polymers to the pavement mixture. Using three given asphalt pavement design mixtures, a 3D-Move mechanistic analysis was performed to determine the fatigue life of three given mixtures: unmodified reference, asphalt rubber, and polymer modified. These mixtures were tested under various axle loading conditions. This mechanistic analysis was then combined with a cost analysis which showed that despite the increase in cost, the asphalt rubber design mixture was the most cost-effective, with the polymer modified mixture finishing in second ahead of the unmodified reference mixture.

3-D Move Mechanistic Analysis and Cost Effectiveness of Asphalt Rubber and Polymer Modified Asphalt Pavement Under Various Axle Loading Conditions

A variety of axle loading conditions can lead to different tensile strains in asphalt pavements. One way to increase resistance to these tensile strains is to add materials such as crumb rubber or polymers to the pavement mixture. Using three given asphalt pavement design mixtures, a 3D-Move mechanistic analysis was performed to determine the fatigue life of three given mixtures: unmodified reference, asphalt rubber, and polymer modified. These mixtures were tested under various axle loading conditions. This mechanistic analysis was then combined with a cost analysis which showed that despite the increase in cost, the asphalt rubber design mixture was the most cost-effective, with the polymer modified mixture finishing in second ahead of the unmodified reference mixture.

Mechanistic Analysis and Economic Benefits of Fiber-Reinforced Asphalt Overlay Mixtures

Among the various distresses in flexible pavement structures, rutting and fatigue cracking can be accounted as two of the major distresses that need to be addressed by pavement engineers. Laboratory tests, such as four-point bending beam and flow number are utilized to characterize the rutting and cracking resistance of flexible pavements. Various construction practices are introduced to reduce the effect of fatigue and rutting in pavement structures. One of such methods is applying fibers to the asphalt mixture to prolong the serviceability and the performance of the pavement structures. The use of fibers is applicable to freshly constructed pavements as well as in the pavement rehabilitation and maintenance work, such as overlay. This paper primarily analyses the application of fibers in the overlay of pavements. The two major cases of the pavement with original asphalt overlay and the one with fibers mixed asphalt overlay is considered utilizing a developed testing program where the mechanistic analysis as well as the economic effectiveness is evaluated. 3D move analysis software package is utilized extensively as a means of mechanistic analysis tool. It is found that the fiber mixture pavement overlay had a higher pavement life than the ordinary asphalt overlay. In addition, the cost effectiveness in terms of fatigue and rutting of fiber-reinforced overlay structures were 4.4 and 4.1 times the unmodified mixtures, respectively. The use of fibers in the overlay of pavement resulted in higher pavement life with a high cost effectiveness

CHANGE IN RESILIENT MODULUS OF BASE LAYERS IN ASPHALT PAVEMENT STRUCTURES OVER TEXAS

The properties of materials change over time and the same case happens for the HMA pavement. The various components of HMA pavement such as surface, base, sub-base, and sub-grade have time related functions. In particular, the base layer which is the immediate layer below the surface, comprising of various materials such as crush aggregates and HMA also have a time related function. Among the numerous properties of the base layers which are dependent with time is its resilient modulus. Therefore, this paper correlates the effect of the change in resilient modulus with time including the various varying conditions such as rutting, thickness of base layer, precipitation, traffic, temperature, IRI index, wheel path length cracked, cracking percentage, crack length, liquid limit, plastic limit, optimum moisture content, and % fine passing below 200 sieve. Each individual factor has different effects over the resilient modulus of the base layer, but their effects are more severe when they act at once in a pavement structure

Worldwide Applications of Geosynthetics Reinforced Walls for Soil Reinforcement

Geosynthetics have become well established construction materials for geotechnical applications in most parts of the world. Because they constitute manufactured materials, new products and applications are developed on a routine basis to provide solutions to routine and critical problems alike. Results from recent research and from monitoring of instrumented structures throughout the years have led to new design methods for different applications of geosynthetics. Because of the significant breath of geosynthetics applications, this paper focuses on recent advances on geosynthetics products, applications and design methodologies for reinforced soil using geosynthetics reinforced walls

International Case Studies of Peat Stabilization by Deep Mixing Method

The purpose of this paper is to advance the knowledge on peat soil stabilization by critically examining and documenting the current state of practice. Deep mixing method is emphasized on column type techniques using lime/cement. This paper is essentially a comprehensive review of available academic literature on deep soil stabilization utilizing this approach. Deep mixing with lime or lime-cement columns and methods of combined soil stabilization with vertical columns are discussed. Furthermore, applications of these methods are illustrated in a variety of conditions and several case histories are presented

Mechanistic and Economical Characteristics of Asphalt Rubber Mixtures

Load associated fatigue cracking is one of the major distress types occurring in flexible pavement systems. Flexural bending beam fatigue laboratory test has been used for several decades and is considered to be an integral part of the new superpave advanced characterization procedure. One of the most significant solutions to prolong the fatigue life for an asphaltic mixture is to utilize flexible materials as rubber. A laboratory testing program was performed on a conventional and Asphalt Rubber- (AR-) gap-graded mixtures to investigate the impact of added rubber on the mechanical, mechanistic, and economical attributes of asphaltic mixtures. Strain controlled fatigue tests were conducted according to American Association of State Highway and Transportation Officials (AASHTO) procedures. The results from the beam fatigue tests indicated that the AR-gap-graded mixtures would have much longer fatigue life compared with the reference (conventional) mixtures. In addition, a mechanistic analysis using 3D-Move software coupled with a cost analysis study based on the fatigue performance on the two mixtures was performed. Overall, analysis showed that AR modified asphalt mixtures exhibited significantly lower cost of pavement per 1000 cycles of fatigue life per mile compared to conventional HMA mixture