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Description
As more and more stadia structures nowadays are being built by making use of new high strength building materials which tend to be lighter than the "old" ones, composite systems and also the fact that engineers, contractors and clients want their structures as optimized as possible, in terms of minimal

As more and more stadia structures nowadays are being built by making use of new high strength building materials which tend to be lighter than the "old" ones, composite systems and also the fact that engineers, contractors and clients want their structures as optimized as possible, in terms of minimal materials used, there is an inevitable side effect that comes with this. The result is that structures are more flexible, and thus they become susceptible to undergone vibration problems due to the action of dynamic loading. Pop/rock concerts, exhibitions, boxing matches, and so forth are staged to supplement the football/sport seasons. Consequently, stadia structures must resist not only static loading, but also dynamic loading, such as the human induced loads from various activities of the spectators which include, standing, jumping, stamping, clapping and dancing, particularly in response to touchdowns (in football matches) or musical beats (during concerts). Active and passive models of humans are studied to see how they influence the response in TCF Bank Stadium for different ranges in excitation frequencies, by performing dynamic analyses and comparing the results with the ones obtained from static analysis. Parameter estimation and system identification in mechanical sciences and structural engineering have become increasingly important areas of research in the last three decades. Many nondestructive testing methods are based on the concepts of system identification and parameter estimation. In this document, two parameter estimation algorithms are studied, namely the Equation Error Estimator and the Output Error Estimator, through the simulation of modal data obtained from a computer structural analysis program and comparisons of their results are presented so that future researchers are better informed about the two and therefore can decide which one would give the best results for their application.
ContributorsAldaco Lopez, Manuel (Author) / Hjelmstad, Keith D. (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Fafitis, Apostolos (Committee member) / Arizona State University (Publisher)
Created2014
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Description
ABSTRACT Enzyme-Induced Carbonate Precipitation (EICP) using a plant-derived form of the urease enzyme to induce the precipitation of calcium carbonate (CaCO3) shows promise as a method of stabilizing soil for the mitigation of fugitive dust. Fugitive dust is a significant problem in Arizona, particularly in Maricopa County. Maricopa County is

ABSTRACT Enzyme-Induced Carbonate Precipitation (EICP) using a plant-derived form of the urease enzyme to induce the precipitation of calcium carbonate (CaCO3) shows promise as a method of stabilizing soil for the mitigation of fugitive dust. Fugitive dust is a significant problem in Arizona, particularly in Maricopa County. Maricopa County is an EPA air quality non-attainment zone, due primarily to fugitive dust, which presents a significant health risk to local residents. Conventional methods for fugitive dust control, including the application of water, are either ineffective in arid climates, very expensive, or limited to short term stabilization. Due to these limitations, engineers are searching for new and more effective ways to stabilize the soil and reduce wind erosion. EICP employs urea hydrolysis, a process in which carbonate precipitation is catalyzed by the urease enzyme, a widely occurring protein found in many plants and microorganisms. Wind tunnel experiments were conducted in the ASU/NASA Planetary Wind Tunnel to evaluate the use of EICP as a means to stabilize soil against fugitive dust emission. Three different soils were tested, including a native Arizona silty-sand, a uniform fine to medium grained silica sand, and mine tailings from a mine in southern Arizona. The test soil was loosely placed in specimen container and the surface was sprayed with an aqueous solution containing urea, calcium chloride, and urease enzyme. After a short period of time to allow for CaCO3 precipitation, the specimens were tested in the wind tunnel. The completed tests show that EICP can increase the detachment velocity compared to bare or wetted soil and thus holds promise as a means of mitigating fugitive dust emissions.
ContributorsKnorr, Brian (Author) / Kavazanjian, Edward (Thesis advisor) / Houston, Sandra (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created2014
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Description
The main objective of this study is to numerically investigate: (i) the ionic transport, especially chloride ion penetration into cementitious materials under imposed electric fields, and (ii) moisture transport through cracked concretes as a function of the crack geometry. Numerical methods were implemented to simulate the ionic transport process, based

The main objective of this study is to numerically investigate: (i) the ionic transport, especially chloride ion penetration into cementitious materials under imposed electric fields, and (ii) moisture transport through cracked concretes as a function of the crack geometry. Numerical methods were implemented to simulate the ionic transport process, based on coupling the Nernst-Planck equation and Poisson's equation to account for transport dominated by electromigration. This mathematical model was also modified to account for the chloride binding mechanism (physical and chemical trapping of chlorides by the cement hydrates) and the concentration dependence of the diffusion coefficient of each ion in the transport process. To validate the numerical model, experimental data from a companion work was used in this study. The non-steady state migration test, which is one of the common accelerated chloride ion transport test, is numerically simulated. The simulation provides a linear relationship between ionic concentration and ionic flux, which indicates that the diffusion part is negligible under a strong external voltage environment. The numerical models along with adjustments for the concentration-dependent diffusion coefficients, a pore structure factor (from electrical measurements) and chloride binding considerations are found to be successful in predicting the chloride penetration depth into plain and modified concretes under imposed electrical potentials. Moisture transport through cracked concrete was examined in the second part of this thesis. To better understand the crack's influence on the permeability, modified Louis' equation was chosen to relate the permeability with crack characteristics. 3D concrete crack models were developed using a MATLAB program with distinct crack tortuosities, roughnesses and sizes. As a comparison, Navier-Stokes equation and the Lattice Boltzmann method were also applied on the 3D model of the cracked concrete to evaluate their permeability. The methodology developed here is expected to be useful in understanding the influence of cracking on moisture transport, and when properly coupled with an ionic transport model that will be further developed, helps comprehensively understand the coupling effects of moisture and ionic transport on deterioration in concrete structures.
ContributorsYang, Pu (Author) / Neithalath, Narayanan (Thesis advisor) / Dharmarajan, Subramaniam (Committee member) / Mobasher, Barzin (Committee member) / Arizona State University (Publisher)
Created2014
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Description
Contrary to many previous travel demand forecasts there is increasing evidence that vehicle travel in developed countries may be peaking. The underlying causes of this peaking are still under much debate and there has been a mobilization of research, largely focused at the national scale, to study the explanatory drivers

Contrary to many previous travel demand forecasts there is increasing evidence that vehicle travel in developed countries may be peaking. The underlying causes of this peaking are still under much debate and there has been a mobilization of research, largely focused at the national scale, to study the explanatory drivers but research focused at the metropolitan scale, where transportation policy and planning are frequently decided, is relatively thin. Additionally, a majority of this research has focused on changes within the activity system without considering the impact transportation infrastructure has on overall travel demand. Using Los Angeles County California, we investigate Peak Car and whether the saturation of automobile infrastructure, in addition to societal and economic factors, may be a suppressing factor. After peaking in 2002, vehicle travel in Los Angeles County in 2010 was estimated at 78 billion and was 20.3 billion shy of projections made in 2002. The extent to which infrastructure saturation may contribute to Peak Car is evaluated by analyzing social and economic factors that may have impacted personal automobile usage over the last decade. This includes changing fuel prices, fuel economy, population growth, increased utilization of alternate transportation modes, changes in driver demographics , travel time and income levels. Summation of all assessed factors reveals there is at least some portion of the 20 billion VMT that is unexplained in all but the worst case scenario. We hypothesize that the unexplained remaining VMT may be explained by infrastructure supply constraints that result in suppression of travel. This finding has impacts on how we see the role of hard infrastructure systems in urban growth and we explore these impacts in the research.
ContributorsFraser, Andrew (Author) / Chester, Mikhail V (Thesis advisor) / Pendyala, Ram M. (Committee member) / Seager, Thomas P (Committee member) / Arizona State University (Publisher)
Created2014
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Description

ABSTRACT Pre-treated crumb rubber technologies are emerging as a new method to produce asphalt rubber mixtures in the field. A new crumb rubber modifier industrially known as "RuBind" is one such technology. RuBindTM is a "Reacted and Activated Rubber" (RAR) that acts like an elastomeric asphalt extender to improve the

ABSTRACT Pre-treated crumb rubber technologies are emerging as a new method to produce asphalt rubber mixtures in the field. A new crumb rubber modifier industrially known as "RuBind" is one such technology. RuBindTM is a "Reacted and Activated Rubber" (RAR) that acts like an elastomeric asphalt extender to improve the engineering properties of the binder and mixtures. It is intended to be used in a dry mixing process with the purpose of simplifying mixing at the asphalt plant. The objectives of this research study were to evaluate the rheological and aging properties of binders modified with RuBindTM and its compatibility with warm mix technology. Two binders were used for this study: Performance Grade (PG) 70-10 and PG 64-22, both modified with 25% by weight of asphalt binder. Laboratory test included: penetration, softening point, viscosity, Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR). Tests were conducted under original, short and long -term aging conditions. Observations from the test results indicated that there is a better improvement when RuBindTM is added to a softer binder, in this case a PG 64-22. For short-term aging, the modified binder showed a similar aging index compared to the control. However, long term aging was favorable for the modified binders. The DSR results showed that the PG 64-22 binder high temperature would increase to 82 °C, and PG 70-10 would be increased to 76 °C, both favorable results. The intermediate temperatures also showed an improvement in fatigue resistance (as measured by the Superpave PG grading parameter |G*|sinä). Test results at low temperatures did not show a substantial improvement, but the results were favorable showing reduced stiffness with the addition of RuBindTM. The evaluation of warm mix additive using EvothermTM confirmed the manufacturer information that the product should have no negative effects on the binder properties; that is the modified binder can be used in a warm mix process. These results were encouraging and the recommendation was to continue with a follow up study with mixture tests using the RuBindTM modified binders.

ContributorsMedina, Jose R. (Jose Roberto) (Author) / Kaloush, Kamil (Thesis advisor) / Underwood, Shane (Thesis advisor) / Mamlouk, Michael (Committee member) / Stempihar, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2014
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Description
Expansive soils impose challenges on the design, maintenance and long-term stability of many engineered infrastructure. These soils are composed of different clay minerals that are susceptible to changes in moisture content. Expansive clay soils wreak havoc due to their volume change property and, in many cases, exhibit extreme swelling and

Expansive soils impose challenges on the design, maintenance and long-term stability of many engineered infrastructure. These soils are composed of different clay minerals that are susceptible to changes in moisture content. Expansive clay soils wreak havoc due to their volume change property and, in many cases, exhibit extreme swelling and shrinking potentials. Understanding what type of minerals and clays react in the presence of water would allow for a more robust design and a better way to mitigate undesirable soil volume change. The relatively quick and widely used method of X-ray Diffraction (XRD) allows identifying the type of minerals present in the soil. As part of this study, three different clays from Colorado, San Antonio Texas, and Anthem Arizona were examined using XRD techniques. Oedometer-type testing was simultaneously preformed in the laboratory to benchmark the behavior of these soils. This analysis allowed performing comparative studies to determining if the XRD technique and interpretation methods currently available could serve as quantitative tools for estimating swell potential through mineral identification. The soils were analyzed using two different software protocols after being subjected to different treatment techniques. Important observations include the formation of Ettringite and Thaumasite, the effect of mixed-layer clays in the interpretation of the data, and the soils being subject to Gypsification. The swelling data obtained from the oedometer-type laboratory testing was compared with predictive swelling functions available from literature. A correlation analysis was attempted in order to find what index properties and mineralogy parameters were most significant to the swelling behavior of the soils. The analysis demonstrated that Gypsification is as important to the swelling potential of the soil as the presence of expansive clays; and it should be considered in the design and construction of structures in expansive soils. Also, the formation of Ettringite and Thaumasite observed during the treatment process validates the evidence of Delayed Ettringite Formation (DEF) reported in the literature. When comparing the measured results with a proposed method from the University of Texas at Arlington (UTA), it was found that the results were somewhat indicative of swell potential but did not explain all causes for expansivity. Finally, it was found that single index properties are not sufficient to estimate the free swell or the swell pressure of expansive soils. In order to have a significant correlation, two or more index properties should be combined when estimating the swell potential. When properties related to the soil mineralogy were correlated with swell potential parameters, the amount of Gypsum present in the soil seems to be as significant to the swell behavior of the soil as the amount of Smectite found.
ContributorsShafer, Zachery (Author) / Zapata, Claudia (Thesis advisor) / Kavazanjian, Edward (Committee member) / Houston, Sandra (Committee member) / Arizona State University (Publisher)
Created2014
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Description

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

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.

ContributorsPaul, Sanjay (Author) / Pendyala, Ram M. (Thesis advisor) / Kaloush, Kamil (Committee member) / Ahn, Soyoung (Committee member) / Arizona State University (Publisher)
Created2014
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Description
The environmental and economic assessment of neighborhood-scale transit-oriented urban form changes should include initial construction impacts through long-term use to fully understand the benefits and costs of smart growth policies. The long-term impacts of moving people closer to transit require the coupling of behavioral forecasting with environmental assessment. Using new

The environmental and economic assessment of neighborhood-scale transit-oriented urban form changes should include initial construction impacts through long-term use to fully understand the benefits and costs of smart growth policies. The long-term impacts of moving people closer to transit require the coupling of behavioral forecasting with environmental assessment. Using new light rail and bus rapid transit in Los Angeles, California as a case study, a life-cycle environmental and economic assessment is developed to assess the potential range of impacts resulting from mixed-use infill development. An integrated transportation and land use life-cycle assessment framework is developed to estimate energy consumption, air emissions, and economic (public, developer, and user) costs. Residential and commercial buildings, automobile travel, and transit operation changes are included and a 60-year forecast is developed that compares transit-oriented growth against growth in areas without close access to high-capacity transit service. The results show that commercial developments create the greatest potential for impact reductions followed by residential commute shifts to transit, both of which may be effected by access to high-capacity transit, reduced parking requirements, and developer incentives. Greenhouse gas emission reductions up to 470 Gg CO2-equivalents per year can be achieved with potential costs savings for TOD users. The potential for respiratory impacts (PM10-equivalents) and smog formation can be reduced by 28-35%. The shift from business-as-usual growth to transit-oriented development can decrease user costs by $3,100 per household per year over the building lifetime, despite higher rental costs within the mixed-use development.
ContributorsNahlik, Matthew (Author) / Chester, Mikhail V (Thesis advisor) / Pendyala, Ram (Committee member) / Fraser, Matthew (Committee member) / Arizona State University (Publisher)
Created2014
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Description
The construction industry has accepted the uncertainty that is included with every project that is initiated. Because of the existing uncertainty, best practices with risk management are commonly recommended and educated to industry participants. However, the current status of the construction industry's ability to manage risk was found to be

The construction industry has accepted the uncertainty that is included with every project that is initiated. Because of the existing uncertainty, best practices with risk management are commonly recommended and educated to industry participants. However, the current status of the construction industry's ability to manage risk was found to be limited, unstructured, and inadequate. Furthermore, many barriers block organizations from implementing and improving risk management practices. A significant barrier with improving risk management methods is the lack of evidence that clearly demonstrates the need to improve risk management practices. Logical explanations of the benefits of risk management doesn't provide the necessary justification or motivation needed for many organizations to dedicate resources towards improving risk management.

Nevertheless, some organizations understand the importance of risk management practices and have begun to measure their risk maturity in order to identify weaknesses and improve risk management practices. Risk maturity measures the organization's ability and perceptions towards risk management. It is possible that many of the barriers to improving risk management would not exist if increased risk maturity was found to have a positive correlation with successful project performance.

The comprehensive hypothesis of the research is that increased risk maturity improves project performance. An exploratory study was conducted on data collected to identify measurable benefits with risk management. Quantitative and qualitative data was collected on 266 construction projects over a seven year period. Multiple statistical analyses were performed on the data and found a positive correlations between risk maturity and project performance. A positive correlations was found between customer satisfaction and contractors risk maturity. Additional findings from the recorded data included the increased ability to predict risks during construction projects within an organization. These findings provide clear reasoning for organizations to devote additional resources in which improve their risk management practices.
ContributorsPerrenoud, Anthony (Author) / Sullivan, Kenneth T. (Thesis advisor) / Weizel, Avi (Committee member) / Badger, William (Committee member) / Arizona State University (Publisher)
Created2014
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Description
Owner organizations in the architecture, engineering, and construction (AEC) industry are presented with a wide variety of project delivery approaches. Implementation of these approaches, while enticing due to their potential to save money, reduce schedule delays, or improve quality, is extremely difficult to accomplish and requires a concerted change management

Owner organizations in the architecture, engineering, and construction (AEC) industry are presented with a wide variety of project delivery approaches. Implementation of these approaches, while enticing due to their potential to save money, reduce schedule delays, or improve quality, is extremely difficult to accomplish and requires a concerted change management effort. Research in the field of organizational behavior cautions that perhaps more than half of all organizational change efforts fail to accomplish their intended objectives. This study utilizes an action research approach to analyze change message delivery within owner organizations, model owner project team readiness and adoption of change, and identify the most frequently encountered types of resistance from lead project members. The analysis methodology included Spearman's rank order correlation, variable selection testing via three methods of hierarchical linear regression, relative weight analysis, and one-way ANOVA. Key findings from this study include recommendations for communicating the change message within owner organizations, empirical validation of critical predictors for change readiness and change adoption among project teams, and identification of the most frequently encountered resistive behaviors within change implementation in the AEC industry. A key contribution of this research is the recommendation of change management strategies for use by change practitioners.
ContributorsLines, Brian (Author) / Sullivan, Kenneth (Thesis advisor) / Wiezel, Avi (Committee member) / Badger, William (Committee member) / Arizona State University (Publisher)
Created2014