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2013

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Articles 1201 - 1230 of 1513

Full-Text Articles in Civil and Environmental Engineering

Improving Productivity Of Tunnel Boring Machines, Nicholas Jencopale Jan 2013

Improving Productivity Of Tunnel Boring Machines, Nicholas Jencopale

Civil Engineering Theses - Archive

Tunneling with tunnel boring machines (TBMs) is one of the most mechanized and sophisticated processes within the construction industry. However, there are risks when venturing down several hundred feet where the conditions cannot be accurately determined in advance. Months and years of planning, engineering, profiling, researching, and scheduling go into a typical tunneling project before any ground breaking event. This thesis will discuss in detail the growing technologies of the tunneling process using tunnel boring machines (TBM). First, some background information on tunneling and the use of a TBM will be provided to introduce the process and the industry being …


Corrosion Potentials Of Lightweight Concrete Wrapped With Fiber Reinforced Polymers (Frp), Eric Goucher Jan 2013

Corrosion Potentials Of Lightweight Concrete Wrapped With Fiber Reinforced Polymers (Frp), Eric Goucher

Civil Engineering Theses - Archive

The purpose of this research was to investigate the effects of Fiber Reinforced Polymer wraps on corrosion protection of lightweight concrete. Many studies have been undertaken for normal density concrete, but there are very few studies regarding lightweight concrete and externally bonded FRP wraps. This experiment involved the use of an accelerated corrosion test to determine the corrosion protection that FRP would afford lightweight concrete, while making a comparison with a similarly proportioned normalweight mix. 42 cylinders were subject to a constant 12 V power from a DC Power Supply while being immersed in a 5% NaCl for a period …


Structural And Material Performance Of Rubberized And Hybrid Concrete Pipes, Mohammad Mohammadagha Jan 2013

Structural And Material Performance Of Rubberized And Hybrid Concrete Pipes, Mohammad Mohammadagha

Civil Engineering Theses - Archive

This study investigates how the combination of steel fiber, crumb rubber, synthetic fiber, and conventional steel cage will improve the ductility of regular concrete pipes and thin-walled semi-rigid concrete pipes. In this study, pipes with four different concrete mixtures were produced and tested: (1) Steel Bar Reinforced Concrete Pipe (SBRCP), (2) Crumb Rubber Reinforced Concrete Pipe (CRRCP), (3) Steel Fiber Reinforced Concrete Pipe (SFRCP), and (4) Synthetic Fiber Reinforced Concrete Pipe (SNFRCP). This study investigates how the variation of the fiber volume fraction and crumb rubber content in concrete mix affects the behavior of pipes with diameters ranging from 24in. …


Ensemble Streamflow Forecasting For The Upper Trinity River Basin In Texas, Manabendra Saharia Jan 2013

Ensemble Streamflow Forecasting For The Upper Trinity River Basin In Texas, Manabendra Saharia

Civil Engineering Theses - Archive

By allowing for routine use of longer-lead quantitative precipitation forecast (QPF) in hydrologic prediction, ensemble forecasting offers hope for extending the lead time for short-range streamflow forecasting. In this work, this potential is assessed by comparatively evaluating ensemble streamflow hindcasts forced by Day 1-3 QPF with those forced by Day 1 QPF for five headwater basins in the Upper Trinity River Basin in North Texas. The hindcasts are generated for a 7-year period of 2004 to 2010 using the Hydrologic Ensemble Forecast Service (HEFS), which operates on the Community Hydrologic Prediction System (CHPS) of the National Weather Service (NWS). HEFS …


The Relation Between Freeway Average Speed And Speed Noise, Bahar Zarin Jan 2013

The Relation Between Freeway Average Speed And Speed Noise, Bahar Zarin

Civil Engineering Theses - Archive

A significant amount of energy could be saved by applying traffic management policies. Many factors affect the fuel consumption rate, and the most important traffic-related ones include variables such as speed, number of stops, the speed noise, and the acceleration noise. Fuel consumption models for both urban and highway traffic are used to evaluate the effect of these factors. Previous literature shows the speed and the acceleration of the individual vehicles as well as the aero-dynamic effects are the most considered parameters in highway fuel consumption models. However, the existing models are based on the average or cruising speed and …


Gis-Based Expert Systems Model For Predicting Habitat Suitability Of Blackside Dace, Benjamin L. Blandford, John Ripy, Ted H. Grossardt, Ryan Evans, Sara Hines Jan 2013

Gis-Based Expert Systems Model For Predicting Habitat Suitability Of Blackside Dace, Benjamin L. Blandford, John Ripy, Ted H. Grossardt, Ryan Evans, Sara Hines

Kentucky Transportation Center Presentations

This study presents a GIS-based predictive habitat suitability model for the blackside dace, a federally-listed threatened species of the Upper Cumberland River basin in southeastern Kentucky. The model is a rules-based system which incorporates expert knowledge about habitat preferences for the species. The five habitat factors identified by experts and included in this model are stream gradient, canopy coverage, riparian vegetation type, riparian zone width, and stream order. Using GIS, the five habitat parameters were parameterized and combined across the entire stream network. Combinations were evaluated by blackside dace experts in terms of habitat suitability. The resulting model was tested …


Characterization Of Impact Damage And Fiber Reinforced Polymer Repair Systems For Metallic Utility Poles, Cara Johnson Jan 2013

Characterization Of Impact Damage And Fiber Reinforced Polymer Repair Systems For Metallic Utility Poles, Cara Johnson

Electronic Theses and Dissertations

Previous studies have demonstrated that the behavior of fiber reinforced polymers (FRPs) bonded to metallic utility poles are governed by the following failure modes; yielding of the metallic substrate, FRP tensile rupture, FRP compressive buckling, and debonding of FRP from the substrate. Therefore, an in situ method can be devised for the repair of utility poles, light poles, and mast arms that returns the poles to their original service strength. This thesis investigates the effect of damage due to vehicular impact on metallic poles, and the effectiveness of externally-bonded FRP repair systems in restoring their capacity. Damage is simulated experimentally …


In-Plant And Distribution System Corrosion Control For Reverse Osmosis, Nanofiltration, And Anion Exchange Process Blends, Samantha Jeffery Jan 2013

In-Plant And Distribution System Corrosion Control For Reverse Osmosis, Nanofiltration, And Anion Exchange Process Blends, Samantha Jeffery

Electronic Theses and Dissertations

The integration of advanced technologies into existing water treatment facilities (WTFs) can improve and enhance water quality; however, these same modifications or improvements may adversely affect finished water provided to the consumer by public water systems (PWSs) that embrace these advanced technologies. Process modification or improvements may unintentionally impact compliance with the provisions of the United States Environmental Protection Agency’s (USEPA’s) Safe Drinking Water Act (SDWA). This is especially true with respect to corrosion control, since minor changes in water quality can affect metal release. Changes in metal release can have a direct impact on a water purveyor’s compliance with …


Experimental And Numerical Investigations On Bond Durability Of Cfrp Strengthened Concrete Members Subjected To Environmental Exposure, Haider Al-Jelawy Jan 2013

Experimental And Numerical Investigations On Bond Durability Of Cfrp Strengthened Concrete Members Subjected To Environmental Exposure, Haider Al-Jelawy

Electronic Theses and Dissertations

Fiber reinforced polymer (FRP) composites have become an attractive alternative to conventional methods for external-strengthening of civil infrastructure, particularly as applied to flexural strengthening of reinforced concrete (RC) members. However, durability of the bond between FRP composite and concrete has shown degradation under some aggressive environments. Although numerous studies have been conducted on concrete members strengthened with FRP composites, most of those studies have focused on the degradation of FRP material itself, relatively few on bond behavior under repeated mechanical and environmental loading. This thesis investigates bond durability under accelerated environmental conditioning of two FRP systems commonly employed in civil …


Monitoring For Underdetermined Underground Structures During Excavation Using Limited Sensor Data, Nader Mehdawi Jan 2013

Monitoring For Underdetermined Underground Structures During Excavation Using Limited Sensor Data, Nader Mehdawi

Electronic Theses and Dissertations

A realistic field monitoring application to evaluate close proximity tunneling effects of a new tunnel on an existing tunnel is presented. A blind source separation (BSS)-based monitoring framework was developed using sensor data collected from the existing tunnel while the new tunnel was excavated. The developed monitoring framework is particularly useful to analyze underdetermined systems due to insufficient sensor data for explicit input force-output deformation relations. The analysis results show that the eigen-parameters obtained from the correlation matrix of raw sensor data can be used as excellent indicators to assess the tunnel structural behaviors during the excavation with powerful visualization …


A Real-Time Crane Service Scheduling Decision Support System (Css-Dss) For Construction Tower Cranes, Amir Tork Jan 2013

A Real-Time Crane Service Scheduling Decision Support System (Css-Dss) For Construction Tower Cranes, Amir Tork

Electronic Theses and Dissertations

The success of construction projects depends on proper use of construction equipment and machinery to a great extent. Thus, appropriate planning and control of the activities that rely on construction equipment could have significant effects on improving the efficiency of project operations. Cranes are the largest and most conspicuous construction equipment, widely used in typical construction sites. They play a major role in relocation of materials in horizontal and vertical directions on construction sites. Given the nature of activities relying on construction cranes in various stages of a project, cranes normally have control over the critical path of the project …


Real-Time Traffic Safety Evaluation Models And Their Application For Variable Speed Limits, Rongjie Yu Jan 2013

Real-Time Traffic Safety Evaluation Models And Their Application For Variable Speed Limits, Rongjie Yu

Electronic Theses and Dissertations

Traffic safety has become the first concern in the transportation area. Crashes have cause extensive human and economic losses. With the objective of reducing crash occurrence and alleviating crash injury severity, major efforts have been dedicated to reveal the hazardous factors that affect crash occurrence at both the aggregate (targeting crash frequency per segment, intersection, etc.,) and disaggregate levels (analyzing each crash event). The aggregate traffic safety studies, mainly developing safety performance functions (SPFs), are being conducted for the purpose of unveiling crash contributing factors for the interest locations. Results of the aggregate traffic safety studies can be used to …


Life Cycle Sustainability Assessment Framework For The U.S. Built Environment, Murat Kucukvar Jan 2013

Life Cycle Sustainability Assessment Framework For The U.S. Built Environment, Murat Kucukvar

Electronic Theses and Dissertations

The overall goals of this dissertation are to investigate the sustainability of the built environment, holistically, by assessing its Triple Bottom Line (TBL): environmental, economic, and social impacts, as well as propose cost-effective, socially acceptable, and environmentally benign policies using several decision support models. This research is anticipated to transform life cycle assessment (LCA) of the built environment by using a TBL framework, integrated with economic input-output analysis, simulation, and multicriteria optimization tools. The major objectives of the outlined research are to (1) build a system-based TBL sustainability assessment framework for the sustainable built environment, by (a) advancing a national …


Sustainability Assessment Of Wind Energy For Buildings, Mehdi Noori Jan 2013

Sustainability Assessment Of Wind Energy For Buildings, Mehdi Noori

Electronic Theses and Dissertations

Due to increasing concerns for global climate change, onshore and offshore wind energy technologies have stimulated a tremendous interest worldwide, and are considered as a viable solution to mitigate the environmental impacts related to electricity generation. Although wind energy technologies have been considered as one of the cleanest energy sources, they have a wide range of direct and indirect environmental impacts when the whole supply chain is considered. This study aims to quantify the direct and indirect environmental impacts of onshore and offshore wind power technologies by tracing all of the economy-wide supply chain requirements. To accomplish this goal, we …


Ozone And Gac Treatment Of A Central Florida Groundwater For Sulfide And Disinfectant By-Product Control, Tara Lamoureux Jan 2013

Ozone And Gac Treatment Of A Central Florida Groundwater For Sulfide And Disinfectant By-Product Control, Tara Lamoureux

Electronic Theses and Dissertations

This study evaluated the combination of ozone and granular activated carbon (GAC) treatment for the removal of sulfide and disinfection byproduct (DBP) precursors in drinking water at the pilot-scale. The research conducted was performed at the Auxiliary (Aux) and Main Water Treatment Plants (WTPs) in Sanford, Florida. Both WTPs rely upon groundwater sources that contain total sulfide ranging from 0.02 to 2.35 mg/L and total organic carbon (TOC) ranging from 0.61 to 2.20 mg/L. The Aux WTP’s raw water contains, on average, 88% more sulfide and 24% more TOC than the Main WTP. Haloacetic acids (HAA5) and total trihalomethanes (TTHMs) …


Chapter Green Nanotechnology: Development Of Nanomaterials For Environmental And Energy Applications, Rachel Fagan, Changseok Han, Joel Andersen, Suresh Pillai, Polycarpos Falaras, Anthony Byrne, Patrick S.M. Dunlop, Hyeok Choi, Wenjun Jiang, Kevin O’Shea, Dionysios D. Dionysiou Jan 2013

Chapter Green Nanotechnology: Development Of Nanomaterials For Environmental And Energy Applications, Rachel Fagan, Changseok Han, Joel Andersen, Suresh Pillai, Polycarpos Falaras, Anthony Byrne, Patrick S.M. Dunlop, Hyeok Choi, Wenjun Jiang, Kevin O’Shea, Dionysios D. Dionysiou

Books/Book Chapters

This book chapter discusses the syntheses of various nanomaterials, for green nanotechnology applications in detail. Special attention is given to the development of emerging areas, such as environmental as well as energy materials. Various approaches for preparing nanostructured photocatalysts, such as titanium dioxide, zinc oxide, iron oxide, and metal sulfides, different conventional methods and novel methods, including sol-gel methods, hydrothermal methods, microwave-assisted methods and sonochemical methods are introduced. The use of nanomaterials as photocatalysts, supporting materials for solar cells, and disinfectants is reported for environmental remediation and energy applications. Advanced applications of nanomaterials for water detoxification, air purification, and the …


Regional Integration Of Renewable Energy Systems In Ireland: The Role Of Hybrid Energy Systems For Small Communities, Craig Goodbody, Eileen Walsh, Kevin Mcdonnell, Philip Owende Jan 2013

Regional Integration Of Renewable Energy Systems In Ireland: The Role Of Hybrid Energy Systems For Small Communities, Craig Goodbody, Eileen Walsh, Kevin Mcdonnell, Philip Owende

Articles

Due to a lack of indigenous fossil energy resources, Ireland’s energy supply constantly teeters on the brink of political, geopolitical, and geographical unease. The potential risk to the security of the energy supply combined with the contribution of anthropogenic greenhouse gas emissions to climate change gives a clear indication of Ireland's need to reduce dependency on imported fossil fuels as primary energy source. A feasibility analysis to investigate the available renewable energy options was conducted using HOMER software. The Net Present Cost, the Cost of Energy, and the CO2 emissions of each potential energy combination were considered in determining the …


Investigation Of Longitudinal Joints Between Precast Prestressed Deck Bulb Tee Girders Using Latex Modified Concrete, Clark Baer Jan 2013

Investigation Of Longitudinal Joints Between Precast Prestressed Deck Bulb Tee Girders Using Latex Modified Concrete, Clark Baer

Theses and Dissertations

This study investigates the behavior and performance of latex modified concrete (LMC) as a closure pour material with a U-bar connection detail in longitudinal joints between precast deck bulb tee bridge girders with integral concrete decks. The objective was to determine if the joint detail was capable of resisting service shear and moment stresses as well as eliminate the formation of cracks in the joint during fatigue loading. This study tested two large scale reinforced concrete slab specimens measuring 6 ft x 6 ft x 8 in joined together by the longitudinal joint detail in fatigue flexure shear loading. The …


Using Weigh-In-Motion Data To Determine Aggressiveness Of Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright Jan 2013

Using Weigh-In-Motion Data To Determine Aggressiveness Of Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright

Articles

This paper presents results based on the analysis of an extensive database of weigh-in-motion (WIM) data collected at five European highway sites in recent years. The data are used as the basis for a Monte Carlo simulation of bridge loading by two lane traffic, both bidirectional and same-direction. Long runs of the simulation model are used to calculate characteristic bridge load effects (bending moments and shear forces), and these characteristic values are compared with design values for bridges of different length as specified by the Eurocode for bridge traffic loading. Various indicators are tested as possible bases for a “Bridge …


Location Of Cerium In Coal-Combustion Fly Ashes: Implications For Recovery Of Lanthanides, James C. Hower, John G. Groppo, Prakash Joshi, Shifeng Dai, David P. Moecher, Michelle N. Johnston Jan 2013

Location Of Cerium In Coal-Combustion Fly Ashes: Implications For Recovery Of Lanthanides, James C. Hower, John G. Groppo, Prakash Joshi, Shifeng Dai, David P. Moecher, Michelle N. Johnston

Coal Combustion and Gasification Products Journal Archive

Given the worldwide demand for rare earth elements (REEs) in modern electronics, all potential sources of the REEs should be investigated. Coal-combustion fly ash represents a potential source of REEs. Fly ashes, derived from the combustion of coals from Kentucky in the United States and Jungar in China, were examined by wavelength-dispersive spectrometry electron microprobe analysis of epoxy-bound polished pellets. From previous studies, it was known that the REEs did not show any enrichment relative to flue gas temperature at the point of collection or to the particle size, that is, external surface area, of the particles. Cerium, the most …


Chemical Partitioning And Mobility Of Trace Elements In Dry Disposed Weathered Ash Conditioned With High-Saline Effluents, S.A. Akinyemi, A. Akinlua, W.M. Gitari, R.O. Akinyeye, L.F. Petrik Jan 2013

Chemical Partitioning And Mobility Of Trace Elements In Dry Disposed Weathered Ash Conditioned With High-Saline Effluents, S.A. Akinyemi, A. Akinlua, W.M. Gitari, R.O. Akinyeye, L.F. Petrik

Coal Combustion and Gasification Products Journal Archive

Weinvestigated the mobility of inorganic elements in the ash dump due to chemical interaction of weathered dry disposed ash conditioned with high-saline effluents and ingressed CO2 from atmosphere and percolating rainwater. Drilled ash core samples collected from dry disposed ash dump at a South African coal-burning power station were characterized using X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses. A modified sequential extraction procedure was selected to determine the mineralogical association of the investigated elements in the 1-year-old drilled ash cores. Major mineral phases are quartz and mullite and other minor phases included hematite, lime, calcite, anorthite, mica, and enstatite. …


Effects Of Coal Combustion By-Product–Encapsulated Ammonium Nitrate On Wheat Yield And Uptake Of Nitrogen And Metals, Eton E. Codling Jan 2013

Effects Of Coal Combustion By-Product–Encapsulated Ammonium Nitrate On Wheat Yield And Uptake Of Nitrogen And Metals, Eton E. Codling

Coal Combustion and Gasification Products Journal Archive

Ammonium nitrate (AN) is an essential plant nutrient for plant growth. Ammonium nitrate is also an ingredient in explosives. Research is being conducted on reducing the explosiveness of AN by encapsulating it with the use of coal by-products. The objective of this greenhouse pot study was to determine the effects of class C and F fly ash and flue gas desulfurization-gypsum-encapsulated AN on biomass, grain, and straw yield and nitrogen and metals uptake by wheat. Encapsulated AN was mixed with a low-nitrogen soil at 56 and 112 kg N ha^-1^, as well as unencapsulated AN as a control, and planted …


Geotechnical Characterization Of Clinker-Stabilized Fly Ash–Coal Mine Overburden Mixes For Subbase Of Mine Haul Road, Soumya Ranjan Mallick, Manoj Kumar Mishra Jan 2013

Geotechnical Characterization Of Clinker-Stabilized Fly Ash–Coal Mine Overburden Mixes For Subbase Of Mine Haul Road, Soumya Ranjan Mallick, Manoj Kumar Mishra

Coal Combustion and Gasification Products Journal Archive

Fly ash is a major by-product of thermal power plants that adversely affects land, water, and air. Its gainful utilization in many areas is being continuously explored. Use of fly ash in opencast coal mine haul road construction is one such option. This article reports detailed laboratory investigations carried out on clinker-stabilized fly ash–mine overburden mixes to evaluate their suitability for subbase of mine haul roads. Composite materials were prepared from fly ash, mine overburden, and clinker at different proportions. Proctor compaction test, unconfined compressive strength (UCS), and ultrasonic pulse velocity tests were carried out at different curing periods. UCS …


Finding The Area Of A Major League Baseball Field, Jacob Courchaine Jan 2013

Finding The Area Of A Major League Baseball Field, Jacob Courchaine

Undergraduate Journal of Mathematical Modeling: One + Two

Using a Major League Baseball (MLB) baseball field template for guidelines, we estimate the cost of building the largest possible field accepted under MLB standards. This includes finding the areas of both the clay and grassy regions and determining how many bags of clay and fertilizer are required to cover the field.


Performance-Based Seismic Design Of Unbonded Precast Post-Tensioned Concrete Filled Gfrp Tube Piers, Haitham M. Dawood, Mohamed Elgawady Jan 2013

Performance-Based Seismic Design Of Unbonded Precast Post-Tensioned Concrete Filled Gfrp Tube Piers, Haitham M. Dawood, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents a seismic design procedure for self-centering precast post-tensioned bridge piers. The piers presented in this manuscript consisted of concrete filled fiber reinforced polymer (FRP) tubes. A large set of 84 piers with different design parameters were analyzed using finite element models. The backbone curve of each pier was developed and bilinearized. The idealized backbone curves were used to develop a set of empirical equations that were able to reproduce the bilinearized backbone curve of a given pier. Different performance criteria have been proposed for the system according to the intensity and the frequency of occurrence of a …


Simulation Modeling And Analysis Of Complex Port Operations With Multimodal Transportation, Mariam Kotachi, Ghaith Rabadi, Mohammad F. Obeid Jan 2013

Simulation Modeling And Analysis Of Complex Port Operations With Multimodal Transportation, Mariam Kotachi, Ghaith Rabadi, Mohammad F. Obeid

Engineering Management & Systems Engineering Faculty Publications

World trade has been increasing dramatically in the past two decades, and as a result containers exchange has grown significantly. Accordingly, container terminals are expanding to meet this increase and new container ports have opened. Ports with one or more container terminals are considered complex systems in which many resources, entities and transporters interact to achieve the objective of safely moving containers delivered by ships inland as well as loading containers delivered by trucks and rail onto ships. Ports with multimodal transportation systems are in particular complex as they typically operate with ships arriving to one or more terminals, multiple …


Investigation Of Usage Of Velocity And Pressure Data Within A Water Distribution Lab Model For Calibrating Hydraulic Models, Robert Craig Ashby Jan 2013

Investigation Of Usage Of Velocity And Pressure Data Within A Water Distribution Lab Model For Calibrating Hydraulic Models, Robert Craig Ashby

Theses and Dissertations--Civil Engineering

Water distribution modeling for hydraulics and water quality is an important tool for managing system performance of water utilities. An important component of a water distribution model is the calibration of a network model with field data in the real world system. The calibration effort requires a protocol or selection criteria for the location of field measurements that best support the calibration effort. A water distribution model was constructed at the University of Kentucky hydraulics lab for the purpose of investigating the performance of water distribution models. The lab model contains numerous hydraulic (pressure, flows) and water quality (concentrations) sensors …


Predicting The Dynamic Behavior Of Coal Mine Tailings Using State-Of-Practice Geotechnical Field Methods, Ali Salehian Jan 2013

Predicting The Dynamic Behavior Of Coal Mine Tailings Using State-Of-Practice Geotechnical Field Methods, Ali Salehian

Theses and Dissertations--Civil Engineering

This study is focused on developing a method to predict the dynamic behavior of mine tailings dams under earthquake loading. Tailings dams are a by-product of coal mining and processing activities. Mine tailings impoundments are prone to instability and failure under seismic loading as a result of the mechanical behavior of the tailings. Due to the existence of potential seismic sources in close proximity to the coal mining regions in the United States, it is necessary to assess the post-earthquake stability of these tailings dams.

To develop the aforementioned methodology, 34 cyclic triaxial tests along with vane shear tests were …


An Experimental Study On Shear Strength Of Chemically-Based Self-Consolidating Concrete, Mahdi Arezoumandi, Jeffery S. Volz Jan 2013

An Experimental Study On Shear Strength Of Chemically-Based Self-Consolidating Concrete, Mahdi Arezoumandi, Jeffery S. Volz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An experimental investigation was conducted to compare the shear strength of full-scale beams constructed with chemically based, self-consolidating concrete (SCC) with conventional concrete (CC). This experimental program consisted of 16 rectangular beams (12 without shear reinforcing and 4 with shear reinforcing in the form of stirrups), 8 beams for each mix design. Additionally, three different longitudinal reinforcement ratios were evaluated within the test matrix. The beam specimens were tested under a simply supported four-point condition. The experimental shear strengths of the beams were compared with both the shear provisions of selected standards (U.S., Australia, Canada, Europe, and Japan) and a …


Rheological Study Of Asphalt Binders With A Wax-Based Warm Mix Additive And Its Relationships To Mix Compaction And Rutting, Rajan Saha Jan 2013

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 …