Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 21 of 21

Full-Text Articles in Engineering

Environmental Study Of The Release Of Btex From Asphalt Modified With Used Motor Oil And Crumb Rubber Modifier, Daniel Bergerson, Magdy Abdelrahman, Mohyeldin Ragab Dec 2014

Environmental Study Of The Release Of Btex From Asphalt Modified With Used Motor Oil And Crumb Rubber Modifier, Daniel Bergerson, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The need to be more environmentally conscious has recently shifted toward the forefront of society. With this new focus on environmentally responsible behavior comes the practice of using recycled materials in construction when possible. Therefore it is necessary to carefully evaluate the safety of any recycled materials being used in pavement materials. Under this study, a reference of testing is presented and implemented to test leachate of samples of two different asphalt binder types containing used motor oil (UMO) and/or crumb rubber modifier (CRM) for the presence of benzene, toluene, ethylbenzene, and xylenes (BTEX). Alongside batch leaching tests, air testing …


Phytoscreening: A Comparison Of In Planta Portable Gc-Ms And In Vitro Analyses, Matt A. Limmer, Gregory D. Martin, Christopher J. Watson, Camilo Martinez, Joel Gerard Burken Dec 2014

Phytoscreening: A Comparison Of In Planta Portable Gc-Ms And In Vitro Analyses, Matt A. Limmer, Gregory D. Martin, Christopher J. Watson, Camilo Martinez, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Phytoscreening Has Been Proven to Rapidly Delineate Subsurface Contaminant Plumes for Semiquantitative Site Assessment, with Minimal Impact to Property or Ecology through the Collection and Analysis of Tree Cores. Here, Three Phytoscreening Methods Were Applied Concurrently to Identify Multiple Chlorinated Volatile Organic Compounds (CVOCs) in a Phytoremediation Treatment System at a Contaminated Industrial Facility. Tree Coring, in Planta Gas Chromatography-Mass Spectrometry (GC-MS), and in Planta Passive Sampling Showed General Agreement, with the in Planta GC-MS Providing the Quickest But Least Quantitative Results. the Portable GC-MS Sampling and Analysis Method Identified Six CVOCs in the Xylem of Hybrid Poplars (Populus Sp.) …


Phytomonitoring Of Chlorinated Ethenes In Trees: A Four-Year Study Of Seasonal Chemodynamics In Planta, Matt A. Limmer, Amanda J. Holmes, Joel Gerard Burken Sep 2014

Phytomonitoring Of Chlorinated Ethenes In Trees: A Four-Year Study Of Seasonal Chemodynamics In Planta, Matt A. Limmer, Amanda J. Holmes, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Long-Term Monitoring (LTM) of Groundwater Remedial Projects is Costly and Time-Consuming, Particularly When using Phytoremediation, a Long-Term Remedial Approach. the Use of Trees as Sensors of Groundwater Contamination (I.e., Phytoscreening) Has Been Widely Described, Although the Use of Trees to Provide Long-Term Monitoring of Such Plumes (Phytomonitoring) Has Been More Limited Due to Unexplained Variability of Contaminant Concentrations in Trees. to Assess This Variability, We Developed an in Planta Sampling Method to Obtain High-Frequency Measurements of Chlorinated Ethenes in Oak (Quercus Rubra) and Baldcypress (Taxodium Distichum) Trees Growing above a Contaminated Plume during a 4-Year Trial. the Data Set Revealed …


Corrosion Resistance Of A Sand Particle-Modified Enamel Coating Applied To Smooth Steel Bars, Fujian Tang, Genda Chen, Richard K. Brow, Michael L. Koenigstein Sep 2014

Corrosion Resistance Of A Sand Particle-Modified Enamel Coating Applied To Smooth Steel Bars, Fujian Tang, Genda Chen, Richard K. Brow, Michael L. Koenigstein

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The protective performance of a sand particle-modified enamel coating on reinforcing steel bars was evaluated in 3.5 wt% NaCl solution by electrochemical impedance spectroscopy (EIS). Seven percentages of sand particles by weight were investigated: 0%, 5%, 10%, 20%, 30%, 50% and 70%. The phase composition of the enamel coating and sand particles were determined with the X-ray diffraction (XRD) technique. The surface and cross-sectional morphologies of the sand particle-modified enamel coating were characterized using scanning electron microscopy (SEM). XRD tests revealed three phases of sand particles: SiO2, CaCO3 and MgCO3. SEM images demonstrated that the …


Modot Pavement Preservation Research Program, David Newton Richardson, Neil Lennart Anderson, John Bowders, Andrew Z. Boeckmann, Ronaldo Luna, S. Michael Lusher, Brent Rosenblad, Lesley Sneed Aug 2014

Modot Pavement Preservation Research Program, David Newton Richardson, Neil Lennart Anderson, John Bowders, Andrew Z. Boeckmann, Ronaldo Luna, S. Michael Lusher, Brent Rosenblad, Lesley Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The following report documents a research project on pavement preservation performed by the Missouri University of Science and Technology (Missouri S&T) and the University of Missouri-Columbia (UMC) on behalf of the Missouri Department of Transportation (MoDOT). the report consists of a Summary Report followed by six detailed technical reports. to achieve the goal of reducing maintenance costs and improving minor road ratings, MoDOT has embarked upon a plan of formalizing its maintenance/preservation planning. to assist in developing the plan, MoDOT contracted with the Missouri S&T and UMC to conduct a research project, entitled "MoDOT Pavement Preservation Research Program". the product …


Splice Performance Evaluation Of Enamel-Coated Rebar For Structural Safety, Genda Chen, Chenglin Wu Jun 2014

Splice Performance Evaluation Of Enamel-Coated Rebar For Structural Safety, Genda Chen, Chenglin Wu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This report summarizes the findings and results from an experimental study of vitreous enamel coating effects on the bond strength between deformed rebar and normal strength concrete. A total of 24 beam splice specimens were tested under four-point loading with four parameters investigated: bar size, lap splice length, coating, and confinement conditions. As the splice length increases, the ratio of bond strength between coated rebar and black rebar first increases from 1.0 to a maximum value of 1.44, and then decreases to 1.0. The maximum bond strength ratio corresponds to the near initial yielding of coated rebar. On the average, …


Unbonded Portland Cement Concrete Overlay/Pavement Monitoring With Integrated Grating And Scattering Optical Fiber Sensors, Genda Chen, Ying Huang, Yi Bao Jun 2014

Unbonded Portland Cement Concrete Overlay/Pavement Monitoring With Integrated Grating And Scattering Optical Fiber Sensors, Genda Chen, Ying Huang, Yi Bao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This report summarizes the findings and results from a laboratory and field study on the strain distribution and crack development in 3" thick concrete panels cast on top of existing concrete pavements as a rapid rehabilitation strategy for roadways. Both fiber Bragg gratings (FBG) and Brillouin Optical Time Domain Reflectometry/Analysis (BOTDR/A) were applied and tested for their feasibility and effectiveness in distributed strain measurement and crack detection. For laboratory tests, six 6'×6" panels were cast similar to their corresponding field construction. Each was tested under both truck loads and under threepoint loads. The performance of distributed BOTDR/A strain measurements was …


Development Of Bridge Girder Movement Criteria For Accelerated Bridge Construction, Genda Chen, Yi Bao Jun 2014

Development Of Bridge Girder Movement Criteria For Accelerated Bridge Construction, Genda Chen, Yi Bao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

End diaphragms connect multiple girders to form a bridge superstructure system for effective resistance to earthquake loads. Concrete girder bridges that include end diaphragms consistently proved to perform well during previous earthquake events. However, whether concrete bridges without end diaphragms are definitively inadequate in seismic performance is yet to be answered. The 2010 Chile Earthquake indicated that properly designed bridge girders and their lateral movement stoppers (shear keys) may perform equally well with those with end diaphragms. In this report, a feasibility study on the design of girder bridges without end diaphragms is presented. This study is particularly significant in …


Utilizing Structural Equation Modeling In The Development Of A Standardized Intervention Assessment Tool, L. E. Voth-Gaeddert, Daniel B. Oerther May 2014

Utilizing Structural Equation Modeling In The Development Of A Standardized Intervention Assessment Tool, L. E. Voth-Gaeddert, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

There are numerous approaches to measuring multidimensional poverty; these include the Human Development Index and the Multidimensional Poverty Index among others [1]. However, a gap in the literature is found when intervention assessment tools are investigated. The idea of creating a standardized assessment tool would allow for a deeper understanding of poverty on a per community basis. Structural Equation Modeling (SEM) offers a robust platform in which to establish such a tool. An overview of SEM and several other general approaches to data aggregation are addressed. The notion of a standardized intervention assessment tool is discussed; this is focused on …


Chemical And Hydrodynamic Mechanisms For Long-Term Geological Carbon Storage, Susan J. Altman, Wen Deng, For Full List Of Authors, See Publisher's Website. May 2014

Chemical And Hydrodynamic Mechanisms For Long-Term Geological Carbon Storage, Susan J. Altman, Wen Deng, For Full List Of Authors, See Publisher's Website.

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Geological storage of CO₂ (GCS), also referred to as carbon sequestration, is a critical component for decreasing anthropogenic CO₂ atmospheric emissions. Stored CO₂ will exist as a supercritical phase, most likely in deep, saline, sedimentary reservoirs. Research at the Center for Frontiers of Subsurface Energy Security (CFSES), a Department of Energy, Energy Frontier Research Center, provides insights into the storage process. The integration of pore-scale experiments, molecular dynamics simulations, and study of natural analogue sites has enabled understanding of the efficacy of capillary, solubility, and dissolution trapping of CO₂ for GCS. Molecular dynamics simulations provide insight on relative wetting of …


Utilizing Mobile Health Technology At The Bottom Of The Pyramid, Sarah E. Oerther, Phalakshi Manjrekar, Daniel B. Oerther May 2014

Utilizing Mobile Health Technology At The Bottom Of The Pyramid, Sarah E. Oerther, Phalakshi Manjrekar, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Among the Millennium Development Goals, MDG 5 Maternal Health has as its dual objectives: (a) reduce by three quarters the maternal mortality ratio; and (b) achieve universal access to reproductive health. Existing maternal health survey instruments were evaluated, modified, adapted, and used to assess perceptions and practices by mothers in villages located in the state of Gujarat in western India as well as women residing in urban Mumbai (formerly Bombay). Women who had recently given birth were asked a series of questions regarding maternal attitudes and behaviors before, during, and shortly after pregnancy including basic health data (i.e., height and …


Plant Translocation Of Organic Compounds: Molecular And Physicochemical Predictors, Matt A. Limmer, Joel Gerard Burken Feb 2014

Plant Translocation Of Organic Compounds: Molecular And Physicochemical Predictors, Matt A. Limmer, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Root-Soil Boundary Represents One of the Largest Global Biotic-Abiotic Mass-Transfer Interfaces and is a Primary Pollutant Entry Point to the Food Chain. This Interface is Also Critically Important in Phytoremediation Efforts and Herbicide Design. Experimental Data and Single-Parameter Models Have Resulted in the Current Understanding that Moderately Hydrophobic Organic Compounds Are Most Likely to Be Translocated by Plants, Although Recent Evidence Indicates Plants Can Also Translocate Some Hydrophilic Compounds. Molecular Descriptors Initially Applied for Drug Discovery and for Transmembrane Migration in Mammalian Systems Were Applied Here to Determine the Physicochemical Domains and Weighted Desirability Functions to Identify Compounds Amenable …


Spatial And Temporal Modeling Of Radar Rainfall Uncertainties, Gabriele Villarini, Bong Chul Seo, Francesco Serinaldi, Witold F. Krajewski Jan 2014

Spatial And Temporal Modeling Of Radar Rainfall Uncertainties, Gabriele Villarini, Bong Chul Seo, Francesco Serinaldi, Witold F. Krajewski

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It is widely acknowledged that radar-based estimates of rainfall are affected by uncertainties (e.g., mis-calibration, beam blockage, anomalous propagation, and ground clutter) which are both systematic and random in nature. Improving the characterization of these errors would yield better understanding and interpretations of results from studies in which these estimates are used as inputs (e.g., hydrologic modeling) or initial conditions (e.g., rainfall forecasting). Building on earlier efforts, the authors apply a data-driven multiplicative model in which the relationship between true rainfall and radar rainfall can be described in terms of the product of a systematic and random component. The systematic …


Study On Surface Permeability Of Concrete Under Immersion, Jun Liu, Feng Xing, Biqin Dong, Hongyan Ma, Dong Pan Jan 2014

Study On Surface Permeability Of Concrete Under Immersion, Jun Liu, Feng Xing, Biqin Dong, Hongyan Ma, Dong Pan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, concrete specimens are immersed in ultrapure water, to study the evolutions of surface permeability, pore structure and paste microstructure following the prolonging of immersion period. According to the results, after 30-day immersion, the surface permeability of concrete becomes higher as compared with the value before immersion. However, further immersion makes the surface permeability decrease, so that the value measured after 150-day immersion is only half that measured after 30-day immersion. The early increase in surface permeability should be mainly attributed to the leaching of calcium hydroxide, while the later decrease to the refinement of pore structure due …


Effect Of Crumb Rubber Dissolution On Low-Temperature Performance And Aging Of Asphalt-Rubber Binder, Amir Ghavibazoo, Magdy Abdelrahman Jan 2014

Effect Of Crumb Rubber Dissolution On Low-Temperature Performance And Aging Of Asphalt-Rubber Binder, Amir Ghavibazoo, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder plays a critical role in defining the low-temperature performance of asphalt pavement, and, therefore, enhancing its mechanical behavior at low service temperatures through modification always has been of great interest. Crumb rubber modification of asphalt is one of the common practices in the industry. However, the effect of a crumb rubber modifier (CRM) on low-temperature performance of the binder is not well understood. A CRM swells by absorbing the aromat-ics and light molecular components of asphalt at low interaction temperatures (i.e., 160°C) and dissolves at higher interaction temperatures (i.e., 190°C, 220°C). Each of those activities affects the performance …


Effects Of Interaction Conditions On Internal Network Structure Of Crumb Rubber-Modified Asphalts, Mohyeldin Ragab, Magdy Abdelrahman Jan 2014

Effects Of Interaction Conditions On Internal Network Structure Of Crumb Rubber-Modified Asphalts, Mohyeldin Ragab, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Investigation of the effect of interaction conditions on the development of the internal network structure of crumb rubber-modified asphalt (CRMA) was carried out. Enhancements in the CRMA physical properties, such as stiffness, expressed in the complex modulus (G*), and elasticity, expressed in the phase angle (δ), as a result of the development of three-dimensional (3-D) entangled network structure were achieved. These results came from controlling the interaction conditions of CRMA synthesis to regulate the crumb rubber-modified (CRM) components that were responsible for the formation of the 3-1) entangled network structure. Dissolution tests and thermogravimetric analysis (TGA) were performed on the …


Parametric Analysis Of Resilient Modulus Modeling For Recycled Asphalt Pavement In Base Layer, Ehab Noureldin, Magdy Abdelrahman Jan 2014

Parametric Analysis Of Resilient Modulus Modeling For Recycled Asphalt Pavement In Base Layer, Ehab Noureldin, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The resilient modulus (MR) has been found to be the most important parameter in the Mechanistic-Empirical Pavement Design Guide (MEPDG) for the base layer. A literature review showed that the use of recycled asphalt pavement (RAP) in the base layer had many economic and structural benefits. The prediction of MR with the specific MEPDG model for the base layer mixed with RAP was found to be reliable for several field conditions. However, further studies of the MEPDG model are needed for an understanding of the physical meaning of each parameter in the model. The most important factor …


Thermophysical And Mechanical Properties Of Hardened Cement Paste With Microencapsulated Phase Change Materials For Energy Storage, Hongzhi Cui, Wenyu Liao, Shazim Ali Memon, Biqin Dong, Waiching Tang Jan 2014

Thermophysical And Mechanical Properties Of Hardened Cement Paste With Microencapsulated Phase Change Materials For Energy Storage, Hongzhi Cui, Wenyu Liao, Shazim Ali Memon, Biqin Dong, Waiching Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this research, structural-functional integrated cement-based materials were prepared by employing cement paste and a microencapsulated phase change material (MPCM) manufactured using urea-formaldehyde resin as the shell and paraffin as the core material. The encapsulation ratio of the MPCM could reach up to 91.21 wt%. Thermal energy storage cement pastes (TESCPs) incorporated with different MPCM contents (5%, 10%, 15%, 20% and 25% by weight of cement) were developed, and their thermal and mechanical properties were studied. The results showed that the total energy storage capacity of the hardened cement specimens with MPCM increased by up to 3.9-times compared with that …


Four-Dimensional Reflectivity Data Comparison Between Two Ground-Based Radars: Methodology And Statistical Analysis, Bong Chul Seo, Witold F. Krajewski, James A. Smith Jan 2014

Four-Dimensional Reflectivity Data Comparison Between Two Ground-Based Radars: Methodology And Statistical Analysis, Bong Chul Seo, Witold F. Krajewski, James A. Smith

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A methodology is proposed to compare radar reflectivity data obtained from two partially overlapping ground-based radars in order to explain relative differences in radar-rainfall products and establish sound merging procedures for multi-radar observing networks. To identify radar calibration differences, radar reflectivity is compared for well-matched radar sampling volumes viewing common meteorological targets. Temporal separation and three-dimensional matching of two different sampling volumes were considered based on the original polar coordinates of radar observation. Since the proposed method assumes radar beam propagation under standard atmospheric conditions, anomalous propagation cases were eliminated from the analysis. The reflectivity comparison results show systematic differences …


Development Of A Tribometer To Characterize Lubrication Layer Properties Of Self-Consolidating Concrete, Dimitri Feys, Kamal Khayat, Aurelien Perez-Schell, Rami Khatib Jan 2014

Development Of A Tribometer To Characterize Lubrication Layer Properties Of Self-Consolidating Concrete, Dimitri Feys, Kamal Khayat, Aurelien Perez-Schell, Rami Khatib

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Last Decade, Significant Advances Have Been Made in Investigating, Understanding and Predicting the Flow Characteristics during Pumping of Concrete. Kaplan Developed Theoretical Equations based on the Rheological and Tribological Properties of Concrete to Predict Pumping Pressures. Several Tribometers Were Developed to Characterize the Flow Properties of Concrete Along a Smooth Wall, But None of Them Allows the Use of Highly Workable Concretes. the Main Reason is that for the Calculation of the Yield Stress and Viscous Constant of the Lubrication Layer, the Concrete is Not Allowed to Be Sheared. in This Paper, a New Design for the Concrete Tribometer …


Cyber-Physical Codesign Of Distributed Structural Health Monitoring With Wireless Sensor Networks, Gregory Hackmann, Weijun Guo, Guirong Yan, Zhuoxiong Sun, Chenyang Lu, Shirley Dyke Jan 2014

Cyber-Physical Codesign Of Distributed Structural Health Monitoring With Wireless Sensor Networks, Gregory Hackmann, Weijun Guo, Guirong Yan, Zhuoxiong Sun, Chenyang Lu, Shirley Dyke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Our Deteriorating Civil Infrastructure Faces the Critical Challenge of Long-Term Structural Health Monitoring for Damage Detection and Localization. in Contrast to Existing Research that Often Separates the Designs of Wireless Sensor Networks and Structural Engineering Algorithms, This Paper Proposes a Cyber-Physical Codesign Approach to Structural Health Monitoring based on Wireless Sensor Networks. Our Approach Closely Integrates 1) Flexibility-Based Damage Localization Methods that Allow a Tradeoff between the Number of Sensors and the Resolution of Damage Localization, and 2) an Energy-Efficient, Multilevel Computing Architecture Specifically Designed to Leverage the Multiresolution Feature of the Flexibility-Based Approach. the Proposed Approach Has Been Implemented …