Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Transportation Engineering (15)
- Physical Sciences and Mathematics (14)
- Environmental Engineering (12)
- Environmental Sciences (8)
- Social and Behavioral Sciences (8)
-
- Materials Science and Engineering (7)
- Mechanical Engineering (7)
- Earth Sciences (6)
- Geotechnical Engineering (6)
- Water Resource Management (5)
- Hydrology (4)
- Business (3)
- Structural Engineering (3)
- Urban Studies and Planning (3)
- Arts and Humanities (2)
- Business Administration, Management, and Operations (2)
- Construction Engineering and Management (2)
- Electrical and Computer Engineering (2)
- Engineering Science and Materials (2)
- Geology (2)
- Public Affairs, Public Policy and Public Administration (2)
- Transportation (2)
- Acoustics, Dynamics, and Controls (1)
- Aerodynamics and Fluid Mechanics (1)
- Aerospace Engineering (1)
- Applied Mechanics (1)
- Architecture (1)
- Institution
- Publication Year
Articles 61 - 90 of 101
Full-Text Articles in Civil Engineering
Evaluation Of Asphalt Pavement Interface, Hyung Jun Ahn
Evaluation Of Asphalt Pavement Interface, Hyung Jun Ahn
Open Access Theses
This paper presents the development process of modified pull-off test for measurement of in-situ pavement interface bonding strength. The modified test method was validated using two case studies (i.e., delaminated vs. non-delaminated pavements on I-65 and intelligent compacted vs. non-intelligent compacted pavements on US-52) and used for developing a correlation model for estimating a probability of delamination failure at a given pull-off bonding strength. In addition, methodologies for probabilistic interpretations with pull-off test results were explored.
The results demonstrated that the modified pull-off test showed its applicability in measurement of interface bonding condition with both weak and strong conditions. Additionally, …
Effect Of Multivalent Ions On The Swelling And Mechanical Behavior Of Superabsorbent Polymers (Saps) For Mitigation Of Mortar Autogenous Shrinkage, Qian Zhu
Open Access Theses
The chemical and physical structure-property relationships of model superabsorbent polymer (SAP) hydrogels were characterized with respect to swelling behavior and mechanical properties in different ionic solutions (Na+ , Ca2+ , and Al3+ ). The model hydrogels were composed of poly(sodium acrylate-acrylamide) (PANa-PAM) copolymer with varying concentrations of PANa (0, 17, 33, 67, and 83 wt.%) and covalent crosslinking densities of 1, 1.5, and 2 wt.%. By synthesizing the hydrogels in-house, systems with independently tunable amounts of covalent crosslinking and anionic functional groups were created, allowing for the relative effects of covalent and ionic crosslinking on the properties of the hydrogels …
Increasing The Supply Of Affordable Housing In Urban India - Mumbai, Upasna Viswanathan
Increasing The Supply Of Affordable Housing In Urban India - Mumbai, Upasna Viswanathan
Open Access Theses
The need for housing in today's world is irrefutable. The growing population, accompanied with the fast pace of urbanization, are producing great housing demand, in urban areas in particular. This study focused on one segment of housing - affordable housing, in Mumbai, India, the demand for which has been on a steady rise over the past decade. Though traditionally the State was the provider of affordable housing, private sector has been increasingly involved in the segment, beginning the economic meltdown of 2008-2009. Yet there is a huge demand-supply gap that exists, which needs to be filled. The researcher looks at …
Excessive Delays In Closeouts Can Be Removed With The Adaptation Of Better Practices, Vasudha Kaul
Excessive Delays In Closeouts Can Be Removed With The Adaptation Of Better Practices, Vasudha Kaul
Open Access Theses
Until recent times, closeout was not given its due diligence simply because the damage it created was not appreciated. Literature, thought-provoking discussions and thoughtful deliberations have punctuated the absolute need for a project closeout planning at the very beginning of a project. Many experienced project managers fail to plan the closeout of a job and concentrate solely on completing the contractual scope of work without paying much heed to the final percent of construction projects, the one percent that is an extremely time-consuming and expensive process if not catered for well in advance. The closeout stage is given its due …
The Hong Kong-Zhu Hai-Macau Bridge: Impacts On The Greater Pearl River Delta, Jun He
The Hong Kong-Zhu Hai-Macau Bridge: Impacts On The Greater Pearl River Delta, Jun He
Open Access Theses
This research looks at the impacts of megaprojects on their host regions through a case study of the Hong Kong-Zhu Hai-Macau Bridge (HZMB). The purpose of this study is to analyze the potential economic impact of the HZMB on the region through existing data and stakeholder interviews. The research will specifically focus on megaprojects' impacts on tourism industry and economic development in general. The research results are aimed to address the four research objectives of the study, which are similarities and differences between the HZBM and other megaprojects, common issues involved in developing megaprojects, the future impacts of the HZMB …
Risk-Based Bridge Inspection Practices, Rebecca Reising
Risk-Based Bridge Inspection Practices, Rebecca Reising
Open Access Theses
Improving bridge safety, reliability, and the allocation of bridge inspection resources are the goals of the proposed risk based bridge inspection practices. Currently, most bridges in the United States are inspected at a fixed calendar interval of 24 months, without regard to the condition of the bridge. Newer bridges with little or no damage are inspected with the same frequency as older, more deteriorated bridges thus creating inefficiency in the allocation of inspection resources. Because of limited resources, it is not possible to spend the necessary time examining bridges that are in poor condition and require extra attention since equal …
Investigating The Role Of Dem Resolution And Accuracy On Flood Inundation Mapping, Siddharth Saksena
Investigating The Role Of Dem Resolution And Accuracy On Flood Inundation Mapping, Siddharth Saksena
Open Access Theses
Saksena, Siddharth. M.S.C.E., Purdue University, May 2014. Investigating the Role of DEM Resolution and Accuracy on Flood Inundation Mapping. Major Professor: Venkatesh Merwade. Topography plays an important role in determining the accuracy of flood inundation maps. A lot of the current flood inundation maps are created using topographic information derived from Light Detection and Ranging (LiDAR) data. Although LiDAR data is very accurate, it is expensive, computationally time consuming and not available in several areas across the United States and around the world. As a result, coarser resolution DEMs which are easily available but less accurate are used for flood …
Floodplain Mapping Using Soil Survey Geographic (Ssurgo) Database, Nikhil Sangwan
Floodplain Mapping Using Soil Survey Geographic (Ssurgo) Database, Nikhil Sangwan
Open Access Theses
Floods are the most damaging of all natural disasters, adversely affecting millions of lives and causing financial losses worth billions of dollars every year across the globe. Flood inundation maps play a key role in assessment and mitigation of the potential flood hazards. However, there are several communities in the United States for which the flood risk maps have not been published yet, as the current flood inundation mapping methods are typically very expensive and time consuming. The objective of this study is to develop and examine an economical alternative approach to floodplain mapping using widely available soil survey data. …
Rheological Properties Of Laponite And Chemically Modified Laponite Suspensions, Meng Shen
Rheological Properties Of Laponite And Chemically Modified Laponite Suspensions, Meng Shen
Open Access Theses
This research investigates the rheological properties of concentrated laponite RD suspensions modified through the addition of laponite RDS and sodium pyrophosphate (SPP). The work is aimed at establishing the possible suitability of these materials for treating liquefaction susceptible sands. This application requires that a laponite suspension initially exhibits liquid like behavior and low viscosity that allow its delivery into the pore space of a sand, but that over time the suspension develop a gel structure with solid like behavior that can serve to restrict sand particle mobility during earthquake shaking.
The experimental program made use of a Physica MCR 301 …
Signalized Corridor Assessment, William Benjamin Smith
Signalized Corridor Assessment, William Benjamin Smith
Open Access Theses
Traffic engineers are often required to investigate the operation of a corridor and determine if there are any areas for improvement. Typical performance measures used to aid in the analysis are volume-to-capacity ratio and average delays based on the Highway Capacity Manual method. Signal timing software might also be used to adjust the split timings in effort to improve the corridor. This thesis discusses procedure to implement split timing optimization and delay analysis to enhance the current process of corridor assessment.
This study examined the newly opened US-231 bypass corridor outside of West Lafayette, IN. Initially, all intersections were operating …
Guidelines For Construction Companies To Decide Between Outsourcing And Self-Performing For Prefabricated Components, Sebastian Soto Ortiz
Guidelines For Construction Companies To Decide Between Outsourcing And Self-Performing For Prefabricated Components, Sebastian Soto Ortiz
Open Access Theses
Prefabrication and modularization has been used in the construction industry for decades. It has recently made a resurgence worldwide providing increased productivity, safety, quality and construction schedule. This research has focused on the situation where a construction company has decided to use prefabrication and faces two possibilities, they either will self-perform or they will outsource the construction of the prefabricated components. The decision making process used by a construction company to determine whether to outsource or self-perform prefabricated components is examined and analyzed.
Prefabrication is an industrial process in which certain components are manufactured in a specialized facility. These items …
Attached-Growth System For Nitrification At Low Temperature, Zhe Sun
Attached-Growth System For Nitrification At Low Temperature, Zhe Sun
Open Access Theses
Attached-growth biological treatment systems have potential to conduct nitrification in cold-temperature climates. In this research, in order to simulate the attached-growth nitrification process (using BOBBER biological reactor) at a real wastewater treatment facility, two laboratory-scale mini-BOBBER systems were installed in a temperature-controlled room and were operated for 101 days with pure ammonium chloride feed solution. Steady-state conditions were approached at 20°C, 15°C, 10°C, and 5°C. In addition, a series of batch experiments were conducted at temperatures of 20°C and 5°C to investigate the relationship between nitrification rate and ammonia-N concentration. Results from these experiments were analyzed and compared with the …
Retrofiting Lid Practices Into Existing Neighborhoods: Is It Worth It?, Timothy Wright
Retrofiting Lid Practices Into Existing Neighborhoods: Is It Worth It?, Timothy Wright
Open Access Theses
Low impact development (LID) practices are gaining popularity as a way to manage stormwater close to the source. This reduces infrastructure requirements and helps to maintain hydrologic processes close to predevelopment conditions. Studies have shown LID practices to be effective in reducing runoff and improving water quality. However, little has been done to aid decision makers in selecting the most effective practices for their needs and budgets.
To this end, the L-THIA LID model has been applied. Using readily available data sources, multiple scenarios can quickly be examined, and then analyzed to determine the cost of implementation and the approximate …
An Analysis On Causes Of Late Final Payment And Release Of Retainage: Electrical Subcontractors’ View, Xuejing Zhang
An Analysis On Causes Of Late Final Payment And Release Of Retainage: Electrical Subcontractors’ View, Xuejing Zhang
Open Access Theses
Using the survey approach, this study identified the underlying causes of late payments and release of retainage for electrical subcontractors, attempting to answer the questions, "What were the minimum, maximum and average delay days of final payment and release of retainage?", "What were the rank of factors in terms of significance on delaying final payment and release of retainage?", and "What were the rank of factors in terms of frequency on delaying final payment and release of retainage?" A survey questionnaire was developed and distributed to about 150 professionals in electrical subcontractors. 29 reports were collected. Based upon the analysis …
Small Strain Stiffness Of A Carbonatic Fine Grained Soil, Sulaiman Dawood
Small Strain Stiffness Of A Carbonatic Fine Grained Soil, Sulaiman Dawood
Open Access Theses
The work presented in this thesis is part of a broad effort aimed at the characterization of the engineering properties, microstructure and mineralogy of soft fine-grained carbonatic soil deposit in Southwestern Indiana (Daviess Co.). The specific focus of this thesis is the characterization, through both field and laboratory measurements, of the small strain behavior of this soil, commonly referred to as a "marl."
Index tests indicate that the 3.5 m marl layer present at the site is characterized by two soil types alternating in small sublayers: a high plasticity silt (soil M) with wn ∼60% and CaCO3 ∼60%, mostly in …
Detailed Finite Element Analysis And Preliminary Study Of The Effects Of Friction And Fastener Pre-Tension On The Mechanical Behavior Of Fastened Built-Up Members, Francisco Javier Bonachera Martin
Detailed Finite Element Analysis And Preliminary Study Of The Effects Of Friction And Fastener Pre-Tension On The Mechanical Behavior Of Fastened Built-Up Members, Francisco Javier Bonachera Martin
Open Access Theses
The characterization of fatigue resistance is one of the main concerns in structural engineering, a concern that is particularly important in the evaluation of existing bridge members designed or erected before the development of fatigue design provisions. The ability of a structural member to develop alternate load paths after the failure of a component is known as member-level or internal redundancy. In fastened built-up members, these alternate load paths are affected by the combination of fastener pre-tension and friction between the structural member components in contact. In this study, a finite element methodology to model and analyze riveted and bolted …
Graphical Performance Measures For Practitioners To Identify Split Failures, Richard Scott Freije
Graphical Performance Measures For Practitioners To Identify Split Failures, Richard Scott Freije
Open Access Theses
Detector occupancy is commonly used to measure traffic signal performance. Despite improvements in controller computational power, there have been relatively few innovations in occupancy-based performance measures or integration with other data. This thesis introduces and demonstrates the use of graphical performance measures based on detector occupancy ratios to verify potential split failures and other signal timing shortcomings reported to practitioners by the public. The proposed performance measures combine detector occupancy during the green interval, detector occupancy during the first five seconds of the red interval, and phase termination cause (gap out or force off). These are summarized by time of …
Manifold Learning Based Spectral Unmixing Of Hyperspectral Remote Sensing Data, Jun-Hwa Chi
Manifold Learning Based Spectral Unmixing Of Hyperspectral Remote Sensing Data, Jun-Hwa Chi
Open Access Dissertations
Nonlinear mixing effects inherent in hyperspectral data are not properly represented in linear spectral unmixing models. Although direct nonlinear unmixing models provide capability to capture nonlinear phenomena, they are difficult to formulate and the results are not always generalizable. Manifold learning based spectral unmixing accommodates nonlinearity in the data in the feature extraction stage followed by linear mixing, thereby incorporating some characteristics of nonlinearity while retaining advantages of linear unmixing approaches. Since endmember selection is critical to successful spectral unmixing, it is important to select proper endmembers from the manifold space. However, excessive computational burden hinders development of manifolds for …
Effect Of Lightweight Aggregate Moisture Content On Internally Cured Concrete, Casey Jones
Effect Of Lightweight Aggregate Moisture Content On Internally Cured Concrete, Casey Jones
Graduate Theses and Dissertations
Putting an end to the rapid deterioration of concrete structures in the United States will only occur through the introduction of better materials and construction methods. The American Society of Civil Engineers (ASCE) reports the overall condition of concrete bridges in the United States to be a "C+". Though better than other areas of the infrastructure, there is still room for improvement in concrete bridges. One major area that may be improved is that of the concrete bridge deck. The bridge deck is comprised of the actual driving surface. It is subject to many deterioration mechanisms including freeze/thaw cycles, de-icing …
Return To Traffic Of Full Depth Reclamation Pavements, Robert Benjamin Hill
Return To Traffic Of Full Depth Reclamation Pavements, Robert Benjamin Hill
Graduate Theses and Dissertations
Full-Depth Reclamation (FDR) is a cost-effective rehabilitation treatment for deteriorated pavements. However, when using asphalt emulsion based rehabilitation techniques one of the most challenging aspects of FDR is determining when traffic can be returned to the rehabilitated pavement surface. Since asphalt emulsion mixtures need ample time for curing, they cannot be sealed with a surface layer until the water has evaporated from the rehabilitated layer. It is often not possible to keep the road closed until all of the water has evaporated and the surface layer is placed, therefore, at some point the traffic needs to be returned to the …
Product Characterization And Headspace Analysis Of Solar Irradiated Aqueous C60 Clusters, Dan Su
Product Characterization And Headspace Analysis Of Solar Irradiated Aqueous C60 Clusters, Dan Su
Open Access Theses
Buckminsterfullerene (C60) is an important fullerene material that has drawn much attention and is currently being applied in many different fields. It was discovered in 1985. As its production has largely increased to meet these industrial needs, it is obvious that its environmental occurrence, especially in aqueous systems, will occur. To further provide information for environmental toxicity studies and for its risk assessment, this thesis focuses on the photo transformation processes of aqueous C60 clusters (Aqu/nC60), with a particular interest in measuring any mineralization that occurs under different irradiation conditions. Two sets of experiments were conducted to test for CO2 …
Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi
Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi
Open Access Dissertations
The objectives of this dissertation are to: (1) review the breadth and depth of land use land cover (LUCC) issues that are being addressed by the land change science community by discussing how an existing model, Purdue's Land Transformation Model (LTM), has been used to better understand these very important issues; (2) summarize the current state-of-the-art in LUCC modeling in an attempt to provide a context for the advances in LUCC modeling presented here; (3) use a variety of statistical, data mining and machine learning algorithms to model single LUCC transitions in diverse regions of the world (e.g. United States …
Interactional Analysis Of Emergent Risks In Institutionally Diverse Construction Projects, Nader Naderpajouh
Interactional Analysis Of Emergent Risks In Institutionally Diverse Construction Projects, Nader Naderpajouh
Open Access Dissertations
Naderpajouh, Nader Ph.D., Purdue University, December 2013. Interactional Analysis of Emergent Risks in Institutionally Diverse Construction Projects. Major Professor: Makarand Hastak.
Construction projects, as complex systems of systems (SOS), increasingly involve institutionally diverse actors that escalate complexity of the projects. Examples of these actors include the export credit agencies, international organizations such as the World Bank, non-governmental organizations (NGO), regulatory actors, transnational organizations, as well as public and community groups. The observed surge in complexity of the projects aim to enhance their robustness in: i) sustaining the increasing demand for service of these projects, and ii) sustaining the contextual fluctuation …
Performance And Cost Analysis Of A Structured Concrete Thermocline Thermal Energy Storage System, Matt Nicholas Strasser
Performance And Cost Analysis Of A Structured Concrete Thermocline Thermal Energy Storage System, Matt Nicholas Strasser
Graduate Theses and Dissertations
Increasing global energy demands and diminishing fossil fuel resources have raised increased interest in harvesting renewable energy resources. Solar energy is a promising candidate, as sufficient irradiance is incident to the Earth to supply the energy demands of all of its inhabitants. At the utility scale, concentrating solar power (CSP) plants provide the most cost-efficient method of harnessing solar energy for conversion to electrical energy. A major roadblock to the large-scale implementation of CSP plants is the lack of thermal energy storage (TES) that would allow the continued production of electricity during the absence of constant irradiance. Sensible heat TES …
Risk Analysis And Reliability Improvement Of Mechanistic-Empirical Pavement Design, Xingqiang Danny Xiao
Risk Analysis And Reliability Improvement Of Mechanistic-Empirical Pavement Design, Xingqiang Danny Xiao
Graduate Theses and Dissertations
Reliability used in the Mechanistic Empirical Pavement Design Guide (MEPDG) is a congregated indicator defined as the probability that each of the key distress types and smoothness will be less than a selected critical level over the design period. For such a complex system as the MEPDG which does not have closed-form design equations, classic reliability methods are not applicable. A robust reliability analysis can rely on Monte Carlo Simulation (MCS). The ultimate goal of this study was to improve the reliability model of the MEPDG using surrogate modeling techniques and Monte Carlo simulation.
To achieve this goal, four tasks …
Effects Of Testing Time On Anaerobic Toxicity Assessment, Omolola Atinuke Akintomide
Effects Of Testing Time On Anaerobic Toxicity Assessment, Omolola Atinuke Akintomide
Graduate Theses and Dissertations
Anaerobic digestion has been widely used for wastewater treatment for decades. Several Anaerobic Toxicity tests have been developed to screen wastewater for toxicity and assess the treatability of such toxicants. However, past research and reviews on Biochemical Methane Potential (BMP) test and Anaerobic Toxicity Assay (ATA) were considered in this study.
The experimental tests included ammonium-nitrogen and sodium chloride toxicity tests with varied concentration and solid retention time. These tests were designed to demonstrate the impact of ammonia- nitrogen and sodium chloride on the biological degradation process. The anaerobic test set-up includes bench-scale test reactors and respirometers used for measuring …
The Development Of A High Performance Concrete To Store Thermal Energy For Concentrating Solar Power Plants, Emerson Esmond John
The Development Of A High Performance Concrete To Store Thermal Energy For Concentrating Solar Power Plants, Emerson Esmond John
Graduate Theses and Dissertations
In recent years, due to rising energy costs as well as an increased awareness of the environmental effects of greenhouse gas emissions produced through traditional forms of energy production, there is great interest in developing alternative sources of energy. One of the most viable alternative energy sources is solar energy. In particular, concentrating solar power (CSP) technologies have been identified as an option for meeting utility needs in the U.S. Southwest. These systems are required to produce electricity not only during periods of high solar radiation but also during times of reduced radiation due to cloud cover, and even extend …
Investigating The Bond Of Prestressing Strands In Lightweight Self-Consolidating Concrete, Royce Woodrow Floyd
Investigating The Bond Of Prestressing Strands In Lightweight Self-Consolidating Concrete, Royce Woodrow Floyd
Graduate Theses and Dissertations
Lightweight self-consolidating concrete (LWSCC) is a relatively recent advancement in concrete technology. The reduced dead load from lightweight concrete is beneficial for precast elements and for elements where dead load is a significant portion of the total load, such as prestressed bridge girders. Self-consolidating concrete (SCC) is a specially proportioned concrete mixture that consolidates under its own weight without the need for vibration. The combination of lightweight concrete and self-consolidating behavior provides the benefits of both. Bond of prestressing steel has been a much debated topic since the 1950s. Limited data are available on the transfer and development length of …
New Insights Into Disinfection Byproduct Formation And Control: Assessing Dissolved Organic Matter Diffusivity And Chemical Functionality, Ashley Pifer
Graduate Theses and Dissertations
Methods were developed for application of asymmetric flow field-flow fractionation (AF4) and fluorescence parallel factor (PARAFAC) analysis to raw and treated samples from drinking water sources to improve characterizations of dissolved organic matter (DOM) and discover DOM properties correlated to disinfection byproduct (DBP) formation potential (FP). Raw water samples were collected from a reservoir, adjusted to pH 6, 7, and 8 and subjected to (1) jar tests using aluminum sulfate (alum) and (2) treatment with magnetic ion exchange (MIEX®) resin. Both treatments were followed by DBPFP tests at pH 7. AF4 was used to size DOM in raw …
Wheel Path Wandering Based On Field Data, Wenting Luo
Wheel Path Wandering Based On Field Data, Wenting Luo
Graduate Theses and Dissertations
The position and width of wheel path on a pavement lane is an important consideration in conducting pavement distress survey, especially for distinguishing longitudinal cracking from fatigue cracking. Currently, the widely used wheel path definition is derived from the LTPP distress manual with fixed width and position, in which the influence of traffic wander on wheel path was overlooked. This thesis attempts to develop a new wheel path definition based on the lateral placement investigation of heavy vehicles' wandering in the field. Generally, the factors influencing vehicle lateral placement can be divided into seven categories, but only four factors are …