Nighttime visibility of pavement markings is provided by glass beads embedded into the striping surface. The glass beads take light from the vehicle headlamps and reflect it back to the driver. This phenomenon is known as retroreflection. Literature suggests that the amount of the bead embedded into the striping surface has a profound impact on the intensity of the retroreflected light. In order to gain insight into how the glass beads provide retroreflection, an experiment was carried out to produce paint stripes with glass beads and measure the retroreflection. Samples were created at various application rates and embedment depths, in an attempt to verify the optimal embedment and observe the effect of application rate on retroreflection. The experiment was conducted using large, airport quality beads and small, road quality beads. Image analysis was used to calculate the degree to which beads were embedded and in an attempt to quantify bead distribution on the stripe surface. The results from the large beads showed that retroreflection was maximized when the beads were embedded approximately seventy percent by bead volume. The results also showed that as the application rate increased, the retroreflection increased, up to a point and then decreased. A model was developed to estimate the retroreflectivity given the amount of beads, bead spacing, and distribution of bead embedment. Results from the small beads were less conclusive, but did demonstrate that the larger beads are better at providing retroreflection. Avenues for future work in this area were identified as the experiment was conducted.

The activity-based approach to travel demand analysis and modeling, which has been developed over the past 30 years, has received tremendous success in transportation planning and policy analysis issues, capturing the multi-way joint relationships among socio-demographic, economic, land use characteristics, activity participation, and travel behavior. The development of synthesizing population with an array of socio-demographic and socio-economic attributes has drawn remarkable attention due to privacy and cost constraints in collecting and disclosing full scale data. Although, there has been enormous progress in producing synthetic population, there has been less progress in the development of population evolution modeling arena to forecast future year population. The objective of this dissertation is to develop a well-structured full-fledged demographic evolution modeling system, capturing migration dynamics and evolution of person level attributes, introducing the concept of new household formations and apprehending the dynamics of household level long-term choices over time. A comprehensive study has been conducted on demography, sociology, anthropology, economics and transportation engineering area to better understand the dynamics of evolutionary activities over time and their impacts in travel behavior. This dissertation describes the methodology and the conceptual framework, and the development of model components. Demographic, socio-economic, and land use data from American Community Survey, National Household Travel Survey, Census PUMS, United States Time Series Economic Dynamic data and United States Center for Disease Control and Prevention have been used in this research. The entire modeling system has been implemented and coded using programming language to develop the population evolution module named `PopEvol' into a computer simulation environment. The module then has been demonstrated for a portion of Maricopa County area in Arizona to predict the milestone year population to check the accuracy of forecasting. The module has also been used to evolve the base year population for next 15 years and the evolutionary trend has been investigated.

One of the main requirements of designing perpetual pavements is to determine the endurance limit of Hot Mix Asphalt (HMA). The purpose of this study was to validate the endurance limit for HMA using laboratory beam fatigue tests. A mathematical procedure was developed to determine the endurance limit of HMA due to healing that occurs during the rest periods between loading cycles. Relating healing to endurance limit makes this procedure unique compared to previous research projects that investigated these concepts separately. An extensive laboratory testing program, including 468 beam tests, was conducted according to AASHTO T321-03 test procedure. Six factors that affect the fatigue response of HMA were evaluated: binder type, binder content, air voids, test temperature, rest period and applied strain. The endurance limit was determined when no accumulated damage occurred indicating complete healing. Based on the test results, a first generation predictive model was developed to relate stiffness ratio to material properties. A second generation stiffness ratio model was also developed by replacing four factors (binder type, binder content, air voids, and temperature) with the initial stiffness of the mixture, which is a basic material property. The model also accounts for the nonlinear effects of the rest period and the applied strain on the healing and endurance limit. A third generation model was then developed by incorporation the number of loading cycles at different locations along the fatigue degradation curve for each test in order to account for the nonlinearity between stiffness ratio and loading cycles. In addition to predicting endurance limit, the model has the ability to predict the number of cycles to failure at any rest period and stiffness combination. The model was used to predict fatigue relationship curves for tests with rest period and determining the K1, K2, and K3 fatigue cracking coefficients. The three generation models predicted close endurance limit values ranging from 22 to 204 micro strains. After developing the third generation stiffness ratio model, the predicted endurance limit values were integrated in the strain-Nf fatigue relationships as a step toward incorporating the endurance limit in the MEPDG software. The results of this study can be used to design perpetual pavements that can sustain a large number of loads if traffic volumes and vehicle weights are controlled.

Perpetual Pavements, if properly designed and rehabilitated, it can last longer than 50 years without major structural rehabilitation. Fatigue endurance limit is a key parameter for designing perpetual pavements to mitigate bottom-up fatigue cracking. The endurance limit has not been implemented in the Mechanistic Empirical Pavement Design Guide software, currently known as DARWin-ME. This study was conducted as part of the National Cooperative Highway Research Program (NCHRP) Project 9-44A to develop a framework and mathematical methodology to determine the fatigue endurance limit using the uniaxial fatigue test. In this procedure, the endurance limit is defined as the allowable tensile strains at which a balance takes place between the fatigue damage during loading, and the healing during the rest periods between loading pulses. The viscoelastic continuum damage model was used to isolate time dependent damage and healing in hot mix asphalt from that due to fatigue. This study also included the development of a uniaxial fatigue test method and the associated data acquisition computer programs to conduct the test with and without rest period. Five factors that affect the fatigue and healing behavior of asphalt mixtures were evaluated: asphalt content, air voids, temperature, rest period and tensile strain. Based on the test results, two Pseudo Stiffness Ratio (PSR) regression models were developed. In the first model, the PSR was a function of the five factors and the number of loading cycles. In the second model, air voids, asphalt content, and temperature were replaced by the initial stiffness of the mix. In both models, the endurance limit was defined when PSR is equal to 1.0 (net damage is equal to zero). The results of the first model were compared to the results of a stiffness ratio model developed based on a parallel study using beam fatigue test (part of the same NCHRP 9-44A). The endurance limit values determined from uniaxial and beam fatigue tests showed very good correlation. A methodology was described on how to incorporate the second PSR model into fatigue analysis and damage using the DARWin-ME software. This would provide an effective and efficient methodology to design perpetual flexible pavements.

Asphalt concrete is the most recycled material in the United States and its reclamation allows the positive reuse of the constituent aggregates and asphalt binder, contributing to the long-term sustainability of the transportation infrastructure; decreasing costs, and the total energy and greenhouse emissions embodied into new materials and infrastructure. Although the national trends in Reclaimed Asphalt Pavements (RAP) usage are encouraging, the environmental conditions in Phoenix, Arizona are extreme and needs further consideration.

The objective of this research study was to evaluate the viability of using RAP in future pavement maintenance and rehabilitation projects for the City. Agencies in the State of Arizona have been slow adopting the use of RAP as a regular practice. While the potential benefits are great, there is some concern on the impact to long-term pavement performance.

RAP millings were sampled from the city’s stockpiles; processed RAP and virgin materials were provided by a local plant. Two asphalt binders were used: PG 70-10 and PG 64-16. RAP variability was evaluated by aggregate gradations; extracted and recovered binder was tested for properties and grading.

A mixture design procedure based on the City’s specifications was defined to establish trial blends. RAP incorporation was based on national and local practices. Four different RAP contents were studied 10%, 15%, 25%, and 25% content with a softer binder, in addition to a control mix (0% RAP).

Performance tests included: dynamic modulus to evaluate stiffness; Flow Number, to assess susceptibility for permanent deformation (rutting); and Tensile Strength Ratio as a measure of susceptibility to moisture damage.

Binder testing showed very stiff recovered asphalts and variable contents with a reasonable variability on aggregate gradations. Performance test results showed slightly higher modulus as RAP content increases, showing a slight improvement related to rutting as well. For moisture damage potential, all mixtures performed well showing improvement for RAP mixtures in most cases.

Statistical analysis showed that 0%, 10%, 15% and 25% with softer binder do not present significant statistical difference among mixtures, indicating that moderate RAP contents are feasible to use within the City paving operations and will not affect greatly nor negatively the pavement performance.

The built environment is responsible for a significant portion of global waste generation.

Construction and demolition (C&D) waste requires significant landfill areas and costs

billions of dollars. New business models that reduce this waste may prove to be financially

beneficial and generally more sustainable. One such model is referred to as the “Circular

Economy” (CE), which promotes the efficient use of materials to minimize waste

generation and raw material consumption. CE is achieved by maximizing the life of

materials and components and by reclaiming the typically wasted value at the end of their

life. This thesis identifies the potential opportunities for using CE in the built environment.

It first calculates the magnitude of C&D waste and its main streams, highlights the top

C&D materials based on weight and value using data from various regions, identifies the

top C&D materials’ current recycling and reuse rates, and finally estimates a potential

financial benefit of $3.7 billion from redirecting C&D waste using the CE concept in the

United States.