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Articles 271 - 300 of 1257

Full-Text Articles in Architectural Engineering

Assessing The Predictive Capability Of The Nno Ballistic Limit Equation For Low-Density Projectile Impact, William P. Schonberg Jan 2023

Assessing The Predictive Capability Of The Nno Ballistic Limit Equation For Low-Density Projectile Impact, William P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The design of nearly all Earth-orbiting spacecraft includes some sort of added shielding that protects the spacecraft against impacts by meteoroids and orbital debris. The effectiveness of the shielding is typically assessed using ballistic limit equations (BLEs) that are developed using data from high-speed impact tests on key spacecraft components and elements. These equations predict whether or not a particular system or structural element will sustain a critical failure following a specific impact event. As such, they are essential components of spacecraft system design as well as any quantitative spacecraft risk assessments that may need to be performed as part …

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Measurement Of Volumetric Deformation, Strain Localization, And Shear Band Characterization During Triaxial Testing Using A Photogrammetry-Based Method, Sara Fayek, Xiong Zhang, Xiaolong Xia, Qingqing Fu, Jeffrey D. Cawlfield Jan 2023

Measurement Of Volumetric Deformation, Strain Localization, And Shear Band Characterization During Triaxial Testing Using A Photogrammetry-Based Method, Sara Fayek, Xiong Zhang, Xiaolong Xia, Qingqing Fu, Jeffrey D. Cawlfield

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Triaxial Testing Has Been Routinely Used as a Standard Laboratory Test that Allows Correct Determination of Soil Characteristics. Previously the Volumetric Strain of the Triaxial Specimen Was Considered to Be Uniformly Distributed Along with the Specimen during the Isotropic and Deviatoric Loading. Although This Assumption Might Hold True under Isotropic Loading, the Effects of Restrained Ends and Disturbance during the Procedures of Specimen Installation and Testing Can Cause Nonuniform Strains throughout the Whole Specimen. This Paper Investigates the Effects of Specimen Preparation and Misalignment on the Strain Uniformity Along with the Soil Specimen during Triaxial Testing. a Series of Consolidated …

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Point Density For Soil Specimen Volume Measurements In Image-Based Methods During Triaxial Testing, Sara Fayek, Xiong Zhang, Javad Galinmoghadam, Jeffrey D. Cawlfield Jan 2023

Point Density For Soil Specimen Volume Measurements In Image-Based Methods During Triaxial Testing, Sara Fayek, Xiong Zhang, Javad Galinmoghadam, Jeffrey D. Cawlfield

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Discrete Measurement Targets Were Frequently Utilized in Image-Based Methods on the Specimen's Surface to Monitor the Soil Specimen during Triaxial Testing. However, the Required Density of Measurement Targets that Should Be Used in Triaxial Testing to Achieve Highly Accurate Volume Measurement Has Not Been Investigated. to overcome This Limitation, This Paper Presents a Parametric Study to Determine the Optimum Target/point Densities to Be Utilized on the Triaxial Soil Specimen Surface to Achieve the Desired Level of Volume Measurement Accuracy in Image-Based Methods. LiDAR Scanning Was Applied to Establish the "Ground Truth" Volume of the Specimen. the Effects of Deformation and …

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Analytical And Numerical Behavior Of Double Composite Steel Bridges, Emad M. Hassan, Hussam Mahmoud Jan 2023

Analytical And Numerical Behavior Of Double Composite Steel Bridges, Emad M. Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel plate girders are considered a viable solution for the construction of medium- to long-span bridges. Despite their many advantages, various concerns have been raised regarding their maintenance due to the potential of fatigue crack initiation at welded details, accelerated corrosion in thin webs, and trapped debris around stiffeners. The use of rolled beams, on the other hand, can be very beneficial because they require much less maintenance. However, they are limited in size, which imposes constraints on their use to relatively short-span bridges due to deflection requirements. In this study, the behavior of the double composite superstructure system was …

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An Insight Into The Effect Of Sharp And Round Edges On The Flow Field-A Cfd Simulation, Abid Hussain, Gao Puzhen, M. Mustafa Azeem, Muhammad Zubair, Muhammad Aamir, Muhammad Irfan Khaleed Jan 2023

An Insight Into The Effect Of Sharp And Round Edges On The Flow Field-A Cfd Simulation, Abid Hussain, Gao Puzhen, M. Mustafa Azeem, Muhammad Zubair, Muhammad Aamir, Muhammad Irfan Khaleed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents a numerical investigation of pressure drop and distribution in a channel around a sharp edge and a disc that is connected to the base of a circular rod. We have employed computational fluid dynamics (CFD)-Fluent for the validation of our models. It was found that the edge sharpness of the disc influences the pressure drop., i.e. sharp edge has higher turbulence and pressure drop. We also observed that pressure drops in the case of the circular disc are less than that of the sharp edge. However, pressure drop has essentially the same values for both shapes after …

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Dissipated Hysteretic Energy Reconstruction For High-Resolution Seismic Monitoring Of Instrumented Buildings, Milad Roochi, Eric M. Hernández, David V. Rosowsky Jan 2023

Dissipated Hysteretic Energy Reconstruction For High-Resolution Seismic Monitoring Of Instrumented Buildings, Milad Roochi, Eric M. Hernández, David V. Rosowsky

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper proposes a high-resolution seismic monitoring framework that employs dissipated energy as a feature for damage detection and localization in instrumented building structures. The the methodology consists of (1) implementing a nonlinear state observer to reconstruct the dynamic response at all degrees of freedom (DoF) of a structural model, (2) employing the reconstructed response to estimate element-by-element forces and displacements, and (3) using estimated displacement, forces, and constitutive laws to estimate elementlevel dissipated energy. The main advantages of the proposed energy-based approach are that i) the proposed feature is physically meaningful and correlates well with the level of cyclic …

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Variation Of Moisture Content And Temperature Under The Road Shoulder Improved With Wicking Geotextile, Javad Galinmoghadam, Xiong Zhang Jan 2023

Variation Of Moisture Content And Temperature Under The Road Shoulder Improved With Wicking Geotextile, Javad Galinmoghadam, Xiong Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Several Pavement Distresses Are Associated with Excess Water in the Pavement System. Hence, Controlling Subsurface Water is Crucial to Pavement's Long-Term Performance. Improving Pavement Drainage is Commonly Used to Control the Water Content in Pavement Layers. Conventional Drainage Systems Can Work under Saturated Conditions but Cannot Effectively Drain Capillary Water. a New Type of Wicking Geotextile Has Been Developed that Can Drain Water under Both Saturated and Unsaturated Conditions. in This Study, the Performance of This New Type of Geotextile in Draining Water from a Paved Road Shoulder is Evaluated. a Full-Scale Test Section Along Interstate 44 Was Constructed and …

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Field Reconnaissance And Observations From The February 6, 2023, Turkey Earthquake Sequence, Gulen Ozkula, Robert K. Dowell, Tugce Baser, Jui Liang Lin, Ozgun A. Numanoglu, Okan Ilhan, C. Guney Olgun, Cheng Wei Huang, Tunc Deniz Uludag Jan 2023

Field Reconnaissance And Observations From The February 6, 2023, Turkey Earthquake Sequence, Gulen Ozkula, Robert K. Dowell, Tugce Baser, Jui Liang Lin, Ozgun A. Numanoglu, Okan Ilhan, C. Guney Olgun, Cheng Wei Huang, Tunc Deniz Uludag

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

On February 6, 2023, a sequence of earthquakes hit Kahraman Maras, Turkey, with magnitudes of M w = 7.8 and 7.5, at 4:17 am and 1:24 pm local time, respectively. According to the records, the M w = 7.8 event was the biggest earthquake since the 1939 Erzincan earthquake of the same magnitude and second-strongest recorded after the 1668 North Anatolia Earthquake. However, it was the most devastating earthquake in the history of Turkey in terms of structural and geotechnical damage and fatalities caused by this. The objective of this article is to explore the aftermath of this major seismic …

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Nucleotide Detection Mechanism And Comparison Based On Low-Dimensional Materials: A Review, M. Mustafa Azeem, Muhammad Shafa, Muhammad Aamir, Muhammad Zubair, Basma Souayeh, Mir Waqas Alam Jan 2023

Nucleotide Detection Mechanism And Comparison Based On Low-Dimensional Materials: A Review, M. Mustafa Azeem, Muhammad Shafa, Muhammad Aamir, Muhammad Zubair, Basma Souayeh, Mir Waqas Alam

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The recent pandemic has led to the fabrication of new nucleic acid sensors that can detect infinitesimal limits immediately and effectively. Therefore, various techniques have been demonstrated using low-dimensional materials that exhibit ultrahigh detection and accuracy. Numerous detection approaches have been reported, and new methods for impulse sensing are being explored. All ongoing research converges at one unique point, that is, an impetus: the enhanced limit of detection of sensors. There are several reviews on the detection of viruses and other proteins related to disease control point of care; however, to the best of our knowledge, none summarizes the various …

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Extending The Nno Ballistic Limit Equation To Foam-Filled Dual-Wall Systems, William P. Schonberg Jan 2023

Extending The Nno Ballistic Limit Equation To Foam-Filled Dual-Wall Systems, William P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A key component in the quantitative assessment of the risk posed to spacecraft by the micrometeoroid and orbital debris (MMOD) environment is frequently referred to as a ballistic limit equation (BLE). A frequently used BLE for dual-wall configurations (which are commonly used on spacecraft to protect them against the MMOD environment) is the New Non-Optimum, or "NNO", BLE. In design applications where a BLE is needed for a new structural system that has not yet been tested, but resembles to a fair degree a dual-wall system, it is common practice to equivalence the materials, thicknesses, etc., of the new system …

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Evaluation Of Thermal And Rheological Properties Of Phase Change Material-Incorporated Asphalt Mastic With Porous Fillers, Farshad Saberi Kerahroudi, Yizhuang David Wang, Jenny Liu Jan 2023

Evaluation Of Thermal And Rheological Properties Of Phase Change Material-Incorporated Asphalt Mastic With Porous Fillers, Farshad Saberi Kerahroudi, Yizhuang David Wang, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Incorporating phase change material (PCM) into paving materials can regulate the pavement temperature, improve the pavement durability, and mitigate the heat-island effects. In this research, porous fillers were used as the PCM carrier, and the thermal and rheological behaviors of the asphalt mastic with the PCM were evaluated. Two different carrier materials (diatomite and expanded perlite) and four types of PCMs were used in the study. The candidate filler, PCM, and proper blending ratios were determined based on the results of scanning electron microscope image analysis, the filter paper test, and the temperature sweep test. The thermal and rheological behaviors …

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Integrating Life-Cycle Analysis Into Civil Infrastructure Resilience Decision Making: Illustrative Application To Seismic Resilience Modeling Of Us Communities, Milad Roohi, Jiate Li, W. Van De Lindt Jan 2023

Integrating Life-Cycle Analysis Into Civil Infrastructure Resilience Decision Making: Illustrative Application To Seismic Resilience Modeling Of Us Communities, Milad Roohi, Jiate Li, W. Van De Lindt

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper aims to integrate life-cycle analysis into civil infrastructure resilience modeling and decision-making in seismic-prone communities. To achieve this aim, the authors present a methodology for modeling seismic life-cycle resilience of interdependent buildings and lifeline systems and subsequently informing resilience decisions directly related to the maintenance and retrofit of interdependent infrastructure to enhance a community’s physical, social, and economic systems. The methodology consists of 1) community data collection, 2) seismic hazard analysis, 3) physical damage analysis, and 4) system-level functionality and restoration analysis, 5) socio-economic impact analysis, 6) life-cycle optimization and retrofit decisionmaking. The methodology begins by developing geospatial …

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Higher-Order Effects In Biaxial Flexure Of Gfrp I-Section Beams, Zia Razzaq, Faridoon Z. Razzaq Jan 2023

Higher-Order Effects In Biaxial Flexure Of Gfrp I-Section Beams, Zia Razzaq, Faridoon Z. Razzaq

Civil & Environmental Engineering Faculty Publications

A theoretical study of Glass Fiber Reinforced Polymer (GFRP) beams subjected to biaxial bending moments is presented with a focus on the influence of higher-order effects on maximum normal stresses. It is shown that the biaxial bending type of loading causes a dramatic increase in the maximum normal stress for a GFRP beam when induced torsional effects are included. The study demonstrates that the traditional first-order theory can grossly underestimate the maximum normal stress in a GFRP beam. Based on the numerical results presented using a higher-order theory which also accounts for induced warping normal stresses, the maximum normal stress …

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Cold-Formed Steel Strength Predictions For Combined Bending And Torsion, Yu Xia, Robert S. Glauz, Benjamin W. Schafer, Michael Seek, Hannah B. Blum Jan 2023

Cold-Formed Steel Strength Predictions For Combined Bending And Torsion, Yu Xia, Robert S. Glauz, Benjamin W. Schafer, Michael Seek, Hannah B. Blum

Engineering Technology Faculty Publications

Locally slender cross-section members, such as cold-formed steel Cee and Zee sections, are susceptible to significant twisting and high warping torsion stresses. Torsion considerations are complicated by whether it is derived as a first-order effect from loading or a second-order effect from instability. The current design for combined bending and torsion interaction has some limitations, including only considering the first yield in torsion and ignoring the cross-section slenderness in torsion. Previous work has derived a simple uniform equation to predict the bimoment capacity and two bimoment strength curves for local and distortional buckling under torsion only. This work is extended …

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2022 Scholarly Productivity Report, Missouri University Of Science And Technology Dec 2022

2022 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.

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Energy Efficiency Retrofit And Decarbonization Of Old And Historic Buildings In California, Daria Nikolaeva Dec 2022

Energy Efficiency Retrofit And Decarbonization Of Old And Historic Buildings In California, Daria Nikolaeva

Master's Projects and Capstones

Buildings are responsible for almost 40% of total global greenhouse gas emissions and the retrofitting of existing buildings is an essential part of solving the problem. About 75% of buildings in Californian were constructed before the first energy-efficiency building code was adopted in 1978. Old buildings are inefficient, responsible for large carbon footprints and must be retrofitted to stay on track with the state's climate targets. However, current policies do not require substantial changes and tend to favor historic preservation over energy efficiency, missing improvement opportunities. Recognizing the significance of carbon intensity, the 2019 California Energy Efficiency Action Plan shifted …

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Applying Unsupervised Machine Learning Clustering Techniques To Early Childcare Soundscapes, Kenton Hummel, Erica E. Ryherd, Iason Konstantzos, Abbie Raikes Dec 2022

Applying Unsupervised Machine Learning Clustering Techniques To Early Childcare Soundscapes, Kenton Hummel, Erica E. Ryherd, Iason Konstantzos, Abbie Raikes

Durham School of Architectural Engineering and Construction: Faculty Publications

Early childhood is a critical time period for language, brain, cognitive, and social/emotional development. Out-of-home childcare is a normative, typical experience for millions of young children. Although Indoor Environmental Quality (IEQ) in K-12 settings has received recent, significant attention, the links between IEQ and children’s learning and development in early childcare settings is a less understood topic. This work focuses specifically on the sound aspect of IEQ in early childcare settings to better understand typical noise levels and occupant experience. Standard approaches to analyzing background noise will be presented alongside more detailed statistical analyses utilizing unsupervised machine learning clustering techniques. …

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Use Of Precious Plastic Method Of Bricks For The Construction Of Tiny Homes, Haylie E. Tallon Dec 2022

Use Of Precious Plastic Method Of Bricks For The Construction Of Tiny Homes, Haylie E. Tallon

Architectural Engineering

Precious Plastics, a Netherlands based company, created an open source project that can be used to create different objects from recycled plastics. The San Luis Obispo area has a large amount of recyclable plastic that is being treated as trash, adding to the pollution of the ocean and the air. This project is to determine the necessary steps to create plastic building blocks, using the Precious Plastic process, as a construction material for low-income, temporary housing. This report covers the process that was used to build two of the machines that will be used to create the bricks. This requires …

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The Bridge Newsletter Winter 2022, Missouri University Of Science And Technology Dec 2022

The Bridge Newsletter Winter 2022, Missouri University Of Science And Technology

The Bridge Newsletter

-Missouri S&T CO2 research is rock solid
-Bringing circular economy to construction projects
-Ph.D. graduate wins Fellowship for solar farm protection research
-Rockne presents 2022 Mathes Lecture on ways to evolve engineering education
-Missouri S&T Ph.D. graduate wins $70,000 Laegeler Fellowship for solar farm protection research

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Basalt Fibers For Underwater Fatigue Repair Of Steel Panels, Guillermo Riveros, Emad M. Hassan, Lauren Hudak, Hussam Mahmoud Nov 2022

Basalt Fibers For Underwater Fatigue Repair Of Steel Panels, Guillermo Riveros, Emad M. Hassan, Lauren Hudak, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fatigue damage is a major threat to the safety and integrity of many steel structures. Steel hydraulic structures (SHS), in particular, experience fatigue loading during operation and are exposed to harsh environmental conditions that can further reduce fatigue life through mechanisms. The traditional inspection and repair process for SHS is time-consuming and leads to economic losses. Studies investigating the behavior and advantages of using bonded carbon fiber-reinforced polymer (CFRP) to repair fatigue cracks in SHS are lacking. The main objectives of this study are to increase the bonding of CFRP, investigate the effectiveness of different fiber-reinforced polymers, and test different …

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Foreign Object Debris Detection For Airport Pavement Images Based On Self-Supervised Localization And Vision Transformer, Travis Munyer, Daniel Brinkman, Xin Zhong, Chenyu Huang, Iason Konstantzos Oct 2022

Foreign Object Debris Detection For Airport Pavement Images Based On Self-Supervised Localization And Vision Transformer, Travis Munyer, Daniel Brinkman, Xin Zhong, Chenyu Huang, Iason Konstantzos

Durham School of Architectural Engineering and Construction: Faculty Publications

Supervised object detection methods provide subpar performance when applied to Foreign Object Debris (FOD) detection because FOD could be arbitrary objects according to the Federal Aviation Administration (FAA) specification. Current supervised object detection algorithms require datasets that contain annotated examples of every to-be-detected object. While a large and expensive dataset could be developed to include common FOD examples, it is infeasible to collect all possible FOD examples in the dataset representation because of the openended nature of FOD. Limitations of the dataset could cause FOD detection systems driven by those supervised algorithms to miss certain FOD, which can become dangerous …

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Optimization Of Mixture Parameter For Physical And Mechanical Properties Of Reactive Powder Concrete Under External Sulfate Attack Using Taguchi Method, Umut Bakhbergen, Chang Seon Shon, Dichuan Zhang, Jong Ryeol Kim, Jenny Liu Oct 2022

Optimization Of Mixture Parameter For Physical And Mechanical Properties Of Reactive Powder Concrete Under External Sulfate Attack Using Taguchi Method, Umut Bakhbergen, Chang Seon Shon, Dichuan Zhang, Jong Ryeol Kim, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Reactive powder concrete (RPC) is defined as a cementitious composite material with an optimized size of granular constituents, very low water-to-binder ratio (w/b), pozzolanic materials like silica fume (SF), and discontinuous fiber reinforcement. RPC applications include bridge decks and girders, seismic columns, wind turbine towers, and pile foundations. Especially, a durable and robust RPC pile foundation with long service life is essential in building construction because continuous maintenance is impossible. Moreover, natural in-situ conditions such as water table, temperature, and sulfate concentration in soil to which the pile foundation is exposed are critical and related to deteriorating the pile foundation. …

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Upcycling Steel Slag In Producing Eco-Efficient Iron–Calcium Phosphate Cement, Yue Ma, Yunlong Luo, Hongyan Ma, Xintao Zhou, Zhongqiu Luo Oct 2022

Upcycling Steel Slag In Producing Eco-Efficient Iron–Calcium Phosphate Cement, Yue Ma, Yunlong Luo, Hongyan Ma, Xintao Zhou, Zhongqiu Luo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In the present study, steel slag powder (SSP) was utilized as the raw material to prepare iron-calcium phosphate cement (ICPC) by reacting with ammonium dihydrogen phosphate (ADP). The influences of the raw materials (SSP/ADP) mass ratios ranging from 2.0 to 7.0 on the properties and microstructures of ICPC pastes were investigated. The compressive strengths of ICPC pastes at all ages firstly increased and then decreased with the increase of SSP/ADP, and the SSP/ADP of 6.0 gave the highest strength. Crystalline mundrabillaite and amorphous phases [i.e. Fe(OH)3, Al(OH)3 and H4SiO4] were formed as the …

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Homogenous Flow Performance Of Steel Fiber-Reinforced Self-Consolidating Concrete For Repair Applications: Developing A New Empirical Set-Up, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat Oct 2022

Homogenous Flow Performance Of Steel Fiber-Reinforced Self-Consolidating Concrete For Repair Applications: Developing A New Empirical Set-Up, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, a new empirical Square-Box test was employed to evaluate the homogeneous flow performance of fiber-reinforced self-consolidating concrete (FR-SCC) under confined-flow conditions that are typical of repair applications. The Square-Box set-up consisted of a closed-circuit box, providing 2.4-m flow distance and a closed-surface cross section of 100-mm width and 200-mm height, equipped with 0 and 4 rows of reinforcing bar grids with 45-mm clear spacing. The flow performance was assessed in terms of dynamic stability and passing ability. The investigated mixtures were considered as diphasic suspensions of fiber-coarse aggregate (F-A > 5 mm) in suspending mortars containing particles finer …

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Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat Oct 2022

Synergistic Effect Of Shrinkage Mitigating Materials On Rheological Properties Of Flowable And Thixotropic Cement Paste, Kamran Aghaee, Ricarda Sposito, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the effect of individual and combined additions of CaO-based expansive agent (EA), shrinkage reducing admixture (SRA), and super absorbent polymer (SAP) on key characteristics of flowable cement paste mixtures proportioned with a water-to-cement ratio of 0.40. Of special interest is the effectiveness of these admixtures to mitigate shrinkage of cementitious materials for 3D printing. Static and dynamic yield stress, plastic and apparent viscosities, and thixotropy were evaluated at 20-min intervals up to 90 min. Compressive strength development and autogenous shrinkage were also determined. A factorial design approach was developed to evaluate the synergetic effects of the shrinkage …

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Spiral Deployment Of Optical Fiber Sensors For Distributed Strain Measurement In Seven-Wire Twisted Steel Cables, Post-Tensioned Against Precast Concrete Bars, Yanping Zhu, Genda Chen Oct 2022

Spiral Deployment Of Optical Fiber Sensors For Distributed Strain Measurement In Seven-Wire Twisted Steel Cables, Post-Tensioned Against Precast Concrete Bars, Yanping Zhu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

On-time monitoring and condition assessments of steel cables provide mission-critical data for informed decision making, ensuring the structural safety of post-tensioned concrete structures. This study aimed to develop a spiral deployment scheme of distributed fiber optic sensors (DFOS) and to monitor/assess the post-tensioned force in seven-wire twisted steel cables, based on the pulse-pre-pump Brillouin optical time domain analysis. Each DFOS was placed in a spiral shape between two surface wires of a steel cable and glued to the steel cable by epoxy. Image observations were conducted to investigate the entireness and bonding condition between the optical fiber and the steel …

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Characterizing And Modeling The Coupled Hydro-Mechanical Cyclic Behavior Of Unsaturated Soils Using Constant Water Content Oedometer And Direct Shear Tests, Beshoy Riad, Xiong Zhang Oct 2022

Characterizing And Modeling The Coupled Hydro-Mechanical Cyclic Behavior Of Unsaturated Soils Using Constant Water Content Oedometer And Direct Shear Tests, Beshoy Riad, Xiong Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Most transportation infrastructures are constructed on compacted soils that are typically unsaturated above the groundwater table. The soils are subjected to cyclic traffic loadings and seasonal wetting–drying cycles. Although problems associated with unsaturated soils are ubiquitous in the US, coupled hydro-mechanical analysis is rarely included in the design/analysis of transportation geosystems. This can be attributed to two main reasons: (a) there are no simple devices/methods which can be used to rapidly characterize stress–strain behavior for unsaturated soils, and (b) there is a lack of a constitutive model to study coupled hydro-mechanical cyclic behavior for unsaturated soils in a consistent way. …

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Benefits And Drawbacks Of Using Multiple Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat Oct 2022

Benefits And Drawbacks Of Using Multiple Shrinkage Mitigating Strategies On Performance Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Shrinkage mitigating strategies have been successfully used to prevent concrete cracking. Numerous studies have demonstrated the efficiency of shrinkage mitigating materials (SMM), such as expansive agent (EA), shrinkage reducing admixture (SRA), and superabsorbent polymer (SAP) on reducing shrinkage and cracking; however, few studies have addressed the limitations of using these materials. In addition, the mechanism of negative effect on microstructure and mechanical properties when these materials are used at high contents or in combinations is not well defined. This study investigates the effect of CaO-based EA, SRA, and SAP on compressive strength development, fiber pull-out strength, and shrinkage of fiber-reinforced …

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A Novel Iron Phosphate Cement Derived From Copper Smelting Slag And Its Early Age Hydration Mechanism, Yunlong Luo, Xintao Zhou, Zhongqiu Luo, Hongyan Ma, Yu Wei, Qin Liu Oct 2022

A Novel Iron Phosphate Cement Derived From Copper Smelting Slag And Its Early Age Hydration Mechanism, Yunlong Luo, Xintao Zhou, Zhongqiu Luo, Hongyan Ma, Yu Wei, Qin Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Copper slag (CS), a by-product of copper smelting, is normally stockpiled, leading to wastes of resource and space as well as environment pollution. It has not been massively reutilized as a supplementary cementitious material in Portland cement due to its low reactivity. In the present study, CS is for the first time utilized as the base component to prepare an iron phosphate cement (IPC) by reacting with ammonium dihydrogen phosphate (ADP) at room temperature. The influence of the raw materials mass ratio (CS/ADP) on the microstructure and performance of IPC pastes are investigated. It is found that the compressive strength …

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Studying Dynamic Pricing In Electrical Power Markets With Distributed Generation: Agent-Based Modeling And Reinforcement-Learning Approach, Gasser G. Ali, Islam H. El-Adaway, Charles Sims, J. Scott Holladay, Chien Fei Chen Oct 2022

Studying Dynamic Pricing In Electrical Power Markets With Distributed Generation: Agent-Based Modeling And Reinforcement-Learning Approach, Gasser G. Ali, Islam H. El-Adaway, Charles Sims, J. Scott Holladay, Chien Fei Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Distributed generation (DG) refers to small-scale generation resources that are located at or near end-consumers, such as photovoltaic (PV) solar systems. DG systems have become increasingly popular in recent years owing to their economic efficiency, reliability, and sustainability. However, the increasing adoption of DG is creating new obstacles for system operators due to the uncertainty in forecasting future demand. One concern is the possibility of facing a utility death spiral as a feedback loop between, on the one hand, the increasing adoption of DG and increasing electricity rates to cover generation and transmission overheads with, on the other hand, reduced …

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