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Missouri University of Science and Technology

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

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Full-Text Articles in Engineering

Quantitative Evaluation Of Asphalt Binder Extraction From Hot Mix Asphalt Pavement Using Ashing And Centrifuge Methods, Ahmed Hemida, Magdy Abdelrahman, Eslam Deef-Allah Oct 2020

Quantitative Evaluation Of Asphalt Binder Extraction From Hot Mix Asphalt Pavement Using Ashing And Centrifuge Methods, Ahmed Hemida, Magdy Abdelrahman, Eslam Deef-Allah

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder requires more investigation to be accurately and precisely extracted since it is a significant procedure for quality control quality assurance (QC/QA) and subsequent binder characterization. In this research, the authors provided a hands-on experience with binder extraction to deliver recommendations concerning the sensitive steps that may affect the outcomes (extracted binder content, Pbe %). Based on the extraction by the centrifuge method, two mineral matter determination methods (ashing and centrifuge) were addressed. Field cores were investigated with comparing the Pbe % to the actual binder content, Pba %. Analysis of variance (ANOVA) and Tukey Post-Hoc statistical analyses ...


Rheological And Component Characterization Of An Innovative Bio-Binder Using Guayule Resin In Partial And Entire Asphalt Replacement, Ahmed Hemida, Magdy Abdelrahman Oct 2020

Rheological And Component Characterization Of An Innovative Bio-Binder Using Guayule Resin In Partial And Entire Asphalt Replacement, Ahmed Hemida, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt cement will not last for a long time as the world encounters a diminishment in the crude oil. For sustainable, flexible pavement development, new resources can provide a contribution to replace it partially or entirely. In this study, asphalt was partially and entirely replaced by guayule resin as a bioresource by-product, extracted during the guayule natural rubber production. Crumb rubber modifier (CRM) was used as an asphalt enhancer. The Superpave grading system was followed at high, intermediate, and low temperatures to evaluate such innovative binder for rutting, fatigue, and thermal cracking, respectively, in addition to viscosity. Therefore, the original ...


Component Analysis Of Bio-Asphalt Binder Using Crumb Rubber Modifier And Guayule Resin As An Innovative Asphalt Replacer, Ahmed Hemida, Magdy Abdelrahman Sep 2020

Component Analysis Of Bio-Asphalt Binder Using Crumb Rubber Modifier And Guayule Resin As An Innovative Asphalt Replacer, Ahmed Hemida, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This research seeks to interpret the component analysis of an innovative bio-asphalt binder using guayule resin in addition to crumb rubber modifier (CRM) at high concentrations. Such asphalt modification aims to minimize the dependency on virgin asphalt binder and provide new solutions concerning sustainable, flexible pavement industry. Guayule resin is a promising bioresource for asphalt binder replacement. By now, it could be considered a no value byproduct extracted during the guayule natural rubber production. CRM is a recycled material derived from scrap tires. The provided interpretation could help in understanding the asphalt-rubber-guayule interaction mechanism. Fourier transform infrared spectroscopy (FTIR), supported ...


Synthesis And Characterization Of Free-Stand Graphene/Silver Nanowire/Graphene Nano Composite As Transparent Conductive Film With Enhanced Stiffness, Chuanrui Guo, Yanxiao Li, Yanping Zhu, Chenglin Wu, Genda Chen Jul 2020

Synthesis And Characterization Of Free-Stand Graphene/Silver Nanowire/Graphene Nano Composite As Transparent Conductive Film With Enhanced Stiffness, Chuanrui Guo, Yanxiao Li, Yanping Zhu, Chenglin Wu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As-grown graphene via chemical vapor deposition (CVD) has potential defects, cracks, and disordered grain boundaries induced by the synthesis and transfer process. Graphene/silver nanowire/graphene (Gr/AgNW/Gr) sandwich composite has been proposed to overcome these drawbacks significantly as the AgNW network can provide extra connections on graphene layers to enhance the stiffness and electrical conductivity. However, the existing substrate (polyethylene terephthalate (PET), glass, silicon, and so on) for composite production limits its application and mechanics behavior study. In this work, a vacuum annealing method is proposed and validated to synthesize the free-stand Gr/AgNW/Gr nanocomposite film on ...


Antimicrobial Resistance Needs To Be Combated At Primary Levels Of Prevention By Nurses, Sarah Oerther, Daniel B. Oerther May 2020

Antimicrobial Resistance Needs To Be Combated At Primary Levels Of Prevention By Nurses, Sarah Oerther, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Identifying Opportunities For Educators To Pursue Collaboration At The Interface Of Nursing And Engineering -- And A Word Of Caution, Daniel B. Oerther, Patricia Yoder-Wise, Beverly Malone Apr 2020

Identifying Opportunities For Educators To Pursue Collaboration At The Interface Of Nursing And Engineering -- And A Word Of Caution, Daniel B. Oerther, Patricia Yoder-Wise, Beverly Malone

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Estimation Of Lubrication Layer Thickness And Composition Through Reverse Engineering Of Interface Rheometry Tests, Alexis Salinas, Dimitri Feys Apr 2020

Estimation Of Lubrication Layer Thickness And Composition Through Reverse Engineering Of Interface Rheometry Tests, Alexis Salinas, Dimitri Feys

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

During concrete pumping, a lubrication layer is formed near the pipe wall. Extensive research has been performed on measuring and modeling the properties of this layer and using these values to predict pumping pressures. However, there are numerous discussions in the literature about the composition and thickness of this layer: can it be considered mortar, a micromortar, or is it cement paste? In this paper, possible solutions for the thickness and composition of the lubrication layer are derived from interface rheometry tests. It is assumed that the lubrication layer is composed of one or more concentric layers of paste or ...


Interfacial Shear Bond Strength Between Steel H-Piles And Polymer Concrete Jackets, Mohanad M. Abdulazeez, Kyle Brown, Mohamed Elgawady Mar 2020

Interfacial Shear Bond Strength Between Steel H-Piles And Polymer Concrete Jackets, Mohanad M. Abdulazeez, Kyle Brown, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel H-piles have been used widely in bridge construction throughout the U.S. because of their relatively large load-carrying capacity while occupying a small area. However, many H-piles suffer from corrosion, which may lead to abrupt collapse. A cost-effective repair technique, including encasing the corroded region of the steel pile into a concrete jacket, which acts as an alternative load path for the applied axial load, has been used by several state Departments of Transportation. Methyl methacrylate polymer concrete (MMA-PC) is a type of concrete that is commonly used as a repair material. However, there is limited research on the ...


Corrosion-Induced Mass Loss Measurement Under Strain Conditions Through Gr/Agnw-Based, Fe-C Coated Lpfg Sensors, Chuanrui Guo, Liang Fan, Genda Chen Mar 2020

Corrosion-Induced Mass Loss Measurement Under Strain Conditions Through Gr/Agnw-Based, Fe-C Coated Lpfg Sensors, Chuanrui Guo, Liang Fan, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, graphene/silver nanowire (Gr/AgNW)-based, Fe-C coated long period fiber gratings (LPFG) sensors were tested up to 72 hours in 3.5 w.t% NaCl solution for corrosion-induced mass loss measurement under four strain levels: 0, 500, 1000 and 1500 µ∈. The crack and interfacial bonding behaviors of laminate Fe-C and Gr/AgNW layer structures were characterized using Scanning Electron Microscopy (SEM) and electrical resistance measurement. Both optical transmission spectra and electrical impedance spectroscopy (EIS) data were simultaneously measured from each sensor. Under increasing strains, transverse cracks appeared first and were followed by longitudinal cracks on ...


The Ethical Challenges Of Antimicrobial Resistance For Nurse Practitioners, Sarah Oerther, Daniel B. Oerther Jan 2020

The Ethical Challenges Of Antimicrobial Resistance For Nurse Practitioners, Sarah Oerther, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Measurement Of Sub-2 Nm Stable Clusters During Silane Pyrolysis In A Furnace Aerosol Reactor, Miguel Vazquez-Pufleau, Yang Wang, Pratim Biswas, Elijah Thimsen Jan 2020

Measurement Of Sub-2 Nm Stable Clusters During Silane Pyrolysis In A Furnace Aerosol Reactor, Miguel Vazquez-Pufleau, Yang Wang, Pratim Biswas, Elijah Thimsen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The initial stages of particle formation are important in several industrial and environmental systems; however, the phenomenon is not completely understood due to the inability to measure cluster size distributions. A high resolution differential mobility analyzer with an electrometer was used to map out the early stages of Si particle formation from pyrolysis of SiH4 in a furnace aerosol reactor. We detected for the first time subnanometer stable clusters from silane pyrolysis, and the diameter was measured to be about 0.7 nm. This diameter is within the range of probable sizes that the reported families of critical silane clusters ...


A New Type Of Crumb Rubber Asphalt Mixture: A Dry Process Design And Performance Evaluation, Feng Ma, Jiasheng Dai, Zhen Fu, Jenny Liu, Wenhao Dong, Zhen Huang Jan 2020

A New Type Of Crumb Rubber Asphalt Mixture: A Dry Process Design And Performance Evaluation, Feng Ma, Jiasheng Dai, Zhen Fu, Jenny Liu, Wenhao Dong, Zhen Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To obtain a crumb rubber asphalt mixture with excellent performance, this study combined trans-polyoctenamer rubber (TOR), crumb rubber, and other additives to establish a new type of crumb rubber (CRT). The objective of this study was to design and evaluate the road performance of the new type of crumb rubber asphalt mixture (CRTAM) with a skeleton dense texture through a dry process. First, the skeleton intrusion compact volume method was used to optimize the grading of coarse and fine aggregates, and the design of the CRTAM gradation was carried out through the same and unequal volume replacement grading method. Then ...


Review On Rheological Characterization Of Bio-Oils/Bio- Binders And Their Applicability In The Flexible Pavement Industry, Ahmed Hemida, Magdy Abdelrahman Dec 2019

Review On Rheological Characterization Of Bio-Oils/Bio- Binders And Their Applicability In The Flexible Pavement Industry, Ahmed Hemida, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper mainly presents a qualitative review on to what extent the bio-oil has the potential to replace asphalt binder for a sustainable, flexible pavement industry. The current research comprises reviews on the rheological characterization of pure bio-oils and bio-oil modified binders (bio-binders) investigated in the literature. The literature showed that several sources of bio-oils have the potential to contribute to the flexible pavement industry. This research mainly discusses the high-temperature properties, especially viscosity for the construction process (mixing and compaction) and viscoelasticity for the elevated temperature of in-service roads. This review paper encourages orientation towards these kinds of renewable ...


Behavior Of Hollow-Core Composite Bridge Columns Having Slender Inner Steel Tubes, Mohanad M. Abdulazeez, Mohamed Elgawady Dec 2019

Behavior Of Hollow-Core Composite Bridge Columns Having Slender Inner Steel Tubes, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper experimentally investigates the seismic behavior of three large-scale hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) columns. An HC-FCS column consisted of a concrete shell sandwiched between an outer glass fiber-reinforced polymer (GFRP) tube and an inner steel tube. Both tubes provided continuous confinement for the concrete shell along with the height of the column. The columns had two different steel tube diameter-to-thickness (Ds/ts) ratios of 85, and 254. Each steel tube was embedded into the footing, with an embedded length of 1.25-1.6 times its diameter, while the GFRP tube was not embedded into the footing. Two columns were ...


Mechanical Properties Of Hydrogenated Amorphous Silicon (A-Si:H) Particles, Taizhi Jiang, Fardin Khabaz, Aniket Marne, Chenglin Wu, Raluca Gearba, Revanth Bodepudi, Roger T. Bonnecaze, Kenneth M. Liechti, Brian A. Korgel Nov 2019

Mechanical Properties Of Hydrogenated Amorphous Silicon (A-Si:H) Particles, Taizhi Jiang, Fardin Khabaz, Aniket Marne, Chenglin Wu, Raluca Gearba, Revanth Bodepudi, Roger T. Bonnecaze, Kenneth M. Liechti, Brian A. Korgel

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A nanoindenter was used to compress individual particles of hydrogenated amorphous silicon (a-Si:H) ranging in diameter from 290 nm to 780 nm. The colloidal synthesis used to produce the particles enables the hydrogen content to be manipulated over a wide range, from about 5 at. % to 50 at. %, making these a-Si:H particles promising for applications in lithium ion batteries, hydrogen storage, and optical metamaterials. Force-displacement curves generated using a tungsten probe flattened with focused ion beam exhibited elastic and then plastic deformations, followed by fracture and crushing of the particles. For particles with 5% and 50% H, Young ...


An Example Of Convergence: Guatemala Research On Wash (Grow), Daniel B. Oerther Nov 2019

An Example Of Convergence: Guatemala Research On Wash (Grow), Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Influence Of Guayule Resin As A Bio-Based Additive On Asphalt-Rubber Binder At Elevated Temperatures, Ahmed Hemida, Magdy Abdelrahman Sep 2019

Influence Of Guayule Resin As A Bio-Based Additive On Asphalt-Rubber Binder At Elevated Temperatures, Ahmed Hemida, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study seeks to find the influence of replacing a portion of the asphalt–rubber binder with the bio-based material “guayule resin.” This replacement could be beneficial in terms of sustainability, economics, and environmental concerns related to the asphalt industry. Nine asphalt-rubber-guayule binders were investigated to find their rheological properties. Consecutively, the study proceeded with five selected binders being compared to the original asphalt (PG64-22). Investigations underwent whole matrices (crumb rubber modifier (CRM) residue included) and liquid phases (CRM residue extracted). Additionally, these properties were partially sought for their corresponding asphalt–rubber binders to compare and judge the contribution of ...


Developing High Performance Magnesium Phosphate Cement Composite Bipolar Plates For Fuel Cells, Wenbin Hao, Hongyan Ma, Guoxing Sun, Zongjin Li Aug 2019

Developing High Performance Magnesium Phosphate Cement Composite Bipolar Plates For Fuel Cells, Wenbin Hao, Hongyan Ma, Guoxing Sun, Zongjin Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, we report a comprehensive study on developing high performance magnesium phosphate cement (MPC) composite bipolar plates for fuel cells. The MPC composite bipolar plates composed of MPC with partial replacement of fly ash as the binding matrix phase and multiple carbon-based materials (including graphite, carbon fiber and multi-walled carbon nanotubes) as the conductive phase. A simple hot-press process was applied to produce the MPC composite. After the optimization on the formula and the structure of the MPC composite and the processing parameters, all the US DOE 2015 technical targets, including electrical conductivity, flexural strength, corrosion resistance were ...


Remote Sensing Of Explosives-Induced Stress In Plants: Hyperspectral Imaging Analysis For Remote Detection Of Unexploded Threats, Paul V. Manley, Vasit Sagan, Felix B. Fritschi, Joel Gerard Burken Aug 2019

Remote Sensing Of Explosives-Induced Stress In Plants: Hyperspectral Imaging Analysis For Remote Detection Of Unexploded Threats, Paul V. Manley, Vasit Sagan, Felix B. Fritschi, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Explosives contaminate millions of hectares from various sources (partial detonations, improper storage, and release from production and transport) that can be life-threatening, e.g., landmines and unexploded ordnance. Exposure to and uptake of explosives can also negatively impact plant health, and these factors can be can be remotely sensed. Stress induction was remotely sensed via a whole-plant hyperspectral imaging system as two genotypes of Zea mays, a drought-susceptible hybrid and a drought-tolerant hybrid, and a forage Sorghum bicolor were grown in a greenhouse with one control group, one group maintained at 60% soil field capacity, and a third exposed to ...


Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin Jul 2019

Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two-dimensional transition metal carbides (MXenes) have attracted a great interest of the research community as a relatively recently discovered large class of materials with unique electronic and optical properties. Understanding of adhesion between MXenes and various substrates is critically important for MXene device fabrication and performance. We report results of direct atomic force microscopy (AFM) measurements of adhesion of two MXenes (Ti3C2Tx and Ti2CTx) with a SiO2 coated Si spherical tip. The Maugis-Dugdale theory was applied to convert the AFM measured adhesion force to adhesion energy, while taking into account surface ...


Load Distribution Of A Prestressed Self-Consolidating Concrete Bridge, Eli S. Hernandez, John J. Myers Jul 2019

Load Distribution Of A Prestressed Self-Consolidating Concrete Bridge, Eli S. Hernandez, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Bridge A7957 is the first Missouri Department of Transportation (MoDOT) large-scale project using self-consolidating concrete (SCC) and high-strength self-consolidating concrete (HS-SCC). The objective of this research was to monitor the initial in-service behavior of the precast-prestressed concrete primary elements of Bridge A7957 and to obtain the load distribution of the bridge using field and finite element models (FEM) data. An initial series of diagnostic load tests was conducted on the bridge superstructure. Embedded sensors recorded strain variations at different section of the instrumented girders for different load configurations. An automated total station (ATS) collected the vertical deflection of the girders ...


Problem-Based Learning As A Pedagogy For Individual Students -- Quantifying The Long-Term Effects Of Land Subsidence And Rising Sea Levels In Coastal Areas For Greater Student Engagement, Sanjay Tewari Jun 2019

Problem-Based Learning As A Pedagogy For Individual Students -- Quantifying The Long-Term Effects Of Land Subsidence And Rising Sea Levels In Coastal Areas For Greater Student Engagement, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Course-based class discussions usually are limited to course syllabus and topics of lectures. If a discussion goes beyond course syllabus and the topics, usually there is a time constraint of class/lab periods, keeping educators and students from going deeper. Even without time constraints of class/lab settings, some students get engaged in the overall learning process more when they are challenged or tasked to solve a problem. This paper focuses on the pedagogical aspect of problem-based learning and its application for greater engagement of these students in quantifying the long term effects of land subsidence and rising sea levels ...


Utility Of Reading Assignments In Environmental Engineering Education For Effective Learning And Greater Student Engagement In An Era Of Innovative Pedagogy And Emerging Technologies, Sanjay Tewari Jun 2019

Utility Of Reading Assignments In Environmental Engineering Education For Effective Learning And Greater Student Engagement In An Era Of Innovative Pedagogy And Emerging Technologies, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Making teaching more effective has been a never-ending pursuit since the dawn of education. Engineering education is no exception to this. There have been numerous pedagogical advances making engineering education more effective. Most engineering majors, some more than others, have dedicated laboratories for hands-on learning of specific concepts and techniques. However, a major portion of teaching still takes places in classroom settings. Educators adopt various pedagogical practices, teaching-aids, and technologies to engage students in the controlled environment of classrooms. In ideal class settings, an instructor should be able to reach out to all students regardless of their learning styles. Introductory ...


Uav/Satellite Multiscale Data Fusion For Crop Monitoring And Early Stress Detection, V. Sagan, M. Maimaitijiang, P. Sidike, M. Maimaitiyiming, H. Erkbol, S. Hartling, K. T. Peterson, J. Peterson, Joel Gerard Burken, F. Fritschi Jun 2019

Uav/Satellite Multiscale Data Fusion For Crop Monitoring And Early Stress Detection, V. Sagan, M. Maimaitijiang, P. Sidike, M. Maimaitiyiming, H. Erkbol, S. Hartling, K. T. Peterson, J. Peterson, Joel Gerard Burken, F. Fritschi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Early stress detection is critical for proactive field management and terminal yield prediction, and can aid policy making for improved food security in the context of climate change and population growth. Field surveys for crop monitoring are destructive, labor-intensive, time-consuming and not ideal for large-scale spatial and temporal monitoring. Recent technological advances in Unmanned Aerial Vehicle (UAV) and high-resolution satellite imaging with frequent revisit time have proliferated the applications of this emerging new technology in precision agriculture to address food security challenges from regional to global scales. In this paper, we present a concept of UAV and satellite virtual constellation ...


Affordable Learning Solutions And Interactive Content In Engineering Mechanics, Nicolas Ali Libre Jun 2019

Affordable Learning Solutions And Interactive Content In Engineering Mechanics, Nicolas Ali Libre

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Digital Affordable Learning Solutions (ALS) provides students with quality yet affordable educational content and enables instructors to utilize multimedia and interactive technology as effective ways of delivering course material. The reduced course content expenses not only allow more students to access the educational material, but also permit the instructors to customize and adapt the material to their teaching style. Incorporation of interactive technology through visually appealing media such as animations, graphics, simulations, videos, and three-dimensional models promotes students' interest in learning theoretical and abstract subjects in science and engineering. In this study, the incorporation of an interactive eBook as an ...


Characterization Of Air Dissolution And Reappearance Under Pressure In Cement Pastes By Means Of Rheology, Daniel Galvez-Moreno, Dimitri Feys, Kyle Riding Apr 2019

Characterization Of Air Dissolution And Reappearance Under Pressure In Cement Pastes By Means Of Rheology, Daniel Galvez-Moreno, Dimitri Feys, Kyle Riding

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete pumping is the most used technique to transfer concrete from the mixer truck to the formwork. Numerous studies have been performed on the flow behavior of concrete in pipes, as well as the consequences of pumping on fluid and hardened concrete properties. One of the negative consequences of pumping concrete is a decrease in freeze-thaw resistance. This is caused by a decrease in air content and an increase in air bubble size, due to dissolution and reappearance of air and air bubble coalescence under pressure. This paper investigates the capability of rheology to understand air dissolution and reappearance in ...


Flexural Behavior Of Hybrid Composite Beam (Hcb) Bridges, Mohamed A. Aboelseoud, John J. Myers Mar 2019

Flexural Behavior Of Hybrid Composite Beam (Hcb) Bridges, Mohamed A. Aboelseoud, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A new hybrid composite beam (HCB) has recently been used in the construction of three bridges in Missouri, USA. HCB consists of self-consolidating concrete (SCC) that is poured into classical arch shape and tied at the ends by steel tendons. Both the concrete and the steel are tucked inside a durable fiberglass shell, and the voids are filled with polyiso foam. This paper aims to examine the flexural behavior of an in-service HCB, evaluate the current methodology and assumptions, and propose modifications to that methodology. To achieve these goals, the strains induced in HCB elements due to different loading stages ...


Seismicity Enhances Macrodispersion In Finite Porous And Fractured Domains: A Pore-Scale Perspective, Lizhi Zheng, Lichun Wang, Wen Deng Mar 2019

Seismicity Enhances Macrodispersion In Finite Porous And Fractured Domains: A Pore-Scale Perspective, Lizhi Zheng, Lichun Wang, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Understanding the effects of oscillating flow field induced by seismicity on the transport process is vital for predicting the fate and transport of solute in many dynamic environments. However, there is prominent discrepancy in arguing with the response of dispersion to the oscillating flow field (i.e., the longitudinal dispersion coefficient would decrease, increase, or maintain unchanged). To unravel the underpinning physics about this controversial response, we simulated two-hundred twenty pore-scale numerical experiments for the seismicity-induced oscillating flow field and associated solute transport in the idealized finite porous (i.e., fluidic plate) and fractured (i.e., parallel plates) domains. The ...


Probabilistic Seismic Demand Analysis Of A Bridge With Unbonded, Post-Tensioned, Concrete-Filled, Fiber-Reinforced Polymer Tube Columns, Manisha Rai, Mohamed Elgawady, Adrian Rodriguez-Marek Mar 2019

Probabilistic Seismic Demand Analysis Of A Bridge With Unbonded, Post-Tensioned, Concrete-Filled, Fiber-Reinforced Polymer Tube Columns, Manisha Rai, Mohamed Elgawady, Adrian Rodriguez-Marek

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Ground motions at sites close to a fault are sometimes affected by forward directivity, where the rupture energy arrives at the site in a form of a very short duration pulse. These pulses impose a heavy demand on structures located in the vicinity of the fault. In this research, a probabilistic seismic demand analysis (PSDA) for a self-centering bridge is carried out. The bridge columns consisted of unbonded, post-tensioned, concrete-filled, fiber-reinforced polymer tubes. A bridge model was developed and non-linear time history analyses were performed. Three different methodologies that used spectral accelerations to predict structural responses were used, and a ...


Review Of Fiber Optic Sensors For Structural Fire Engineering, Yi Bao, Ying Huang, Matthew S. Hoehler, Genda Chen Feb 2019

Review Of Fiber Optic Sensors For Structural Fire Engineering, Yi Bao, Ying Huang, Matthew S. Hoehler, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Reliable and accurate measurements of temperature and strain in structures subjected to fire can be difficult to obtain using traditional sensing technologies based on electrical signals. Fiber optic sensors, which are based on light signals, solve many of the problems of monitoring structures in high temperature environments; however, they present their own challenges. This paper, which is intended for structural engineers new to fiber optic sensors, reviews various fiber optic sensors that have been used to make measurements in structure fires, including the sensing principles, fabrication, key characteristics, and recently-reported applications. Three categories of fiber optic sensors are reviewed: Grating-based ...