Engineering Commons^™

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 tested as as-built …

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 …

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's …

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

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Inter-Comparison Of Reflectivity Measurements Between Gpm Dpr And Nexrad Radars, Munsung Keem, Bong Chul Seo, Witold F. Krajewski, K. Robert Morris

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study demonstrates the potential use of the NASA's Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR) to examine ground radar (GR) miscalibration and other uncertainty sources (e.g., partial beam blockage). We acquired the GPM Ground Validation System Validation Network reflectivity matchups between the DPR and three GRs (two in Iowa and one in South Dakota) for 2014–2017. We then refined the matching parameters (e.g., time separation) to reduce uncertainty in the matchup samples by analyzing the sensitivity of the matchup statistical properties to changes in these parameters. To reconcile the same observables (i.e., reflectivity) with different observational properties among …

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 the guayule …

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

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

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 (Ti₃C₂T_x and Ti₂CT_x) 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 …

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 …

Artificial Neural Network Model For Bridge Deterioration And Assessment, G. Ali, A. Elsayegh, R. Assaad, Islam H. El-Adaway, I. S. Abotaleb

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Missouri has the seventh largest number of bridges nationwide, yet must maintain its inventory with funding from just the fourth lowest gasoline tax in the country. Estimation and prediction of the condition of bridges is necessary to create and optimize future maintenance, repair, and rehabilitation plans as well as to assign the necessary associated budgets. Previous studies have used statistical analysis, fuzzy logic, and Markovian models to develop algorithms for predicting future bridge conditions. Due to the non-linear nature of the relationship between the characteristics of bridges and their deterioration behavior, Artificial Neural Networks (ANN) have shown to be more …

Contractual Guidelines For Contractors Working Under Projects Funded By Southeastern Us Dots, Islam H. El-Adaway, Amr Elsayegh, I. S. Abotaleb, C. Smith, M. Bootwala, S. Eteifa

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Transportation projects in the infrastructure sector contribute to approximately 42% of the total expenditures on public construction projects in the US. The main source of funding of these projects is the taxpayer's hard-earned money. The ever-growing problem by transportation projects is that the available funds are less than those required to have a stable and well maintained transportation network. Unnecessary costs in these projects are mainly caused by Conflicts, Claims and Disputes (C2D). According to recent reports, C2D in construction is greatly attributed to poor contract administration. The goal of this paper is to provide better understanding and utilization of …

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 …

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 …

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

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

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 numerically obtained breakthrough …

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 …

Mechanism Of Tricalcium Silicate Hydration In The Presence Of Polycarboxylate Polymers, Rachel Cook, Hongyan Ma, Aditya Kumar

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Abstract: The early-age hydration of cement is inhibited in the presence of comb-shaped polycarboxylate ether (PCE) polymer -- a dispersant commonly added to control rheological properties of fresh cement paste. This study employs a series of microcalorimetry experiments and phase boundary nucleation and growth simulations to elucidate the effects of dosage and molecular architecture of PCE on hydration of tricalcium silicate (Ca₃SiO₅ or C₃S in cement notation), the dominant phase in cement. Results show that PCE -- regardless of its molecular architecture -- suppresses early-age hydration of C₃S. PCE-induced retardation becomes increasingly more …

Balancing The Performance And Environmental Concerns Of Used Motor Oil As Rejuvenator In Asphalt Mixes, Eslam Deef-Allah, Magdy Abdelrahman, Mark W. Fitch, Mohyeldin Ragab, Mousumi Bose, Xiaolong He

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Road deterioration inspires researchers to enhance the properties of asphalt binder for better performing mixes. Recycled tire rubber, or crumb rubber modifier (CRM), and used motor oil (UMO) are two modifiers that enhance asphalt binder performance through two different mechanisms. CRM affects high-temperature properties while UMO modifies low-temperature properties. Potential environmental concerns arising from the use of UMO have been raised in the literature. In this paper, the two recycled materials were investigated for their ability to complement each other. Both performance benefits of using both materials and the environmental concerns of using UMO were studied. Four CRM asphalt binders …

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 …

Sea Level Rise And Land Subsidence In Coastal Louisiana: Forecasting, Mapping And Identification Of At-Risk Transportation Infrastructure, Sanjay Tewari, Francis Manning, Wesley Palmer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The coast of Louisiana is under threat because of sea level rise and land subsidence. Sea water is encroaching deeper inland and as a result Louisiana is losing land at an alarming rate. The combined effect of sea level rise and land subsidence is variable spatially. This paper focuses on this combined effect in identifying the transportation infrastructure that is at risk of getting affected by the seawater inundation of the land.

This paper attempts to account for land elevation data monitored continuously at various locations along the coast of Louisiana and combining it with local sea level rise to …

Smart Building And Construction Materials, Donglu Shi, Julian Wang, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

In Situ Mechanical Characterization Of The Mixed- Mode Fracture Strength Of The Cu/Si Interface For Tsv Structures, Chenglin Wu, Congjie Wei, Yanxiao Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In situ nanoindentation experiments have been widely adopted to characterize material behaviors of microelectronic devices. This work introduces the latest developments of nanoindentation experiments in the characterization of nonlinear material properties of 3D integrated microelectronic devices using the through-silicon via (TSV) technique. The elastic, plastic, and interfacial fracture behavior of the copper via and matrix via interface were characterized using small-scale specimens prepared with a focused ion beam (FIB) and nanoindentation experiments. A brittle interfacial fracture was found at the Cu/Si interface under mixed-mode loading with a phase angle ranging from 16.7° to 83.7°. The mixed-mode fracture strengths were extracted …

Smart Building And Construction Materials, Donglu Shi, Julian Wang, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Advances and innovations in materials science and engineering have always played a substantial role in civil engineering, building structural design, and construction. In recent years, extensive effort has been devoted to the applications of stimuli-responsive smart materials and nanostructures in buildings. These smart materials used in the built environment can be defined as those offering specific functional and adaptable properties in response to thermal, optical, structural, and environmental stimuli. Not only do these materials enhance the overall performance of new building construction but also promise safer structures, longer durability of building elements, efficient building energy savings, greater environmental sustainability, and …