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Articles 211 - 240 of 7868

Full-Text Articles in Civil and Environmental Engineering

Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali Jan 2025

Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali

Materials Science and Engineering Faculty Research & Creative Works

Efficient oxide scale removal is critical for maintaining surface quality and process efficiency in steel manufacturing. This study optimizes water jet descaling by evaluating the performance of flat and rotary jet nozzles under varying process parameters. Using a combined approach of experimental analysis and computational fluid dynamics, it investigates the influence of pressure (138–275 bar), lead angle (0°, 15°, 25°), working distance (50–100 mm), and spray angle (15°–25°) on descaling efficiency. Findings indicate that flat jet nozzles achieve superior performance at short working distances due to concentrated impact forces, while rotary jet nozzles sustain efficiency over extended distances through dynamic …


Ultrafast Belite (Β-C2s) Production Using Biofuel-Based Combustion Synthesis, Shubham Agrawal, Sayee Srikarah Volaity, Oluwadamilare Charles Adesina, Bryan K. Aylas-Paredes, Taihao Han, Srinivas Kilambi, Aditya Kumar, Narayanan Neithalath Jan 2025

Ultrafast Belite (Β-C2s) Production Using Biofuel-Based Combustion Synthesis, Shubham Agrawal, Sayee Srikarah Volaity, Oluwadamilare Charles Adesina, Bryan K. Aylas-Paredes, Taihao Han, Srinivas Kilambi, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

This study presents a novel low-temperature, combustion synthesis (CS) approach for the rapid production of belite-rich cements. CS leverages the exothermic heat released from the combustion of biofuels such as lignin and/or biomass, intermixed with pelletized limestone and quartz. At an imposed furnace temperature of ∼700°C (as opposed to 1200°C–1300°C required in a conventional kiln), the source materials are rapidly transformed to belite, resulting in energy, emissions, and economic benefits. This work explores the influence of various process parameters, viz., fuel types and contents, airflow rate, porosity, holding temperature, and holding time on the efficiency of CS-based belite synthesis. Through …


Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck Jan 2025

Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck

Materials Science and Engineering Faculty Research & Creative Works

The effect of gating system design on the inclusion population and size distribution in an aluminum-killed low-alloy advanced high strength steel casting was studied. A mold with four different gating systems: pressurized and non-pressurized with side risers, naturally pressurized with a side riser, and naturally pressurized with a top riser, was designed using computational fluid dynamics and solidification software. The design allowed inclusion populations in castings produced with each gating system to be compared during the same pouring event. Samples taken from different positions just below the top surface of each casting were analyzed using an SEM/EDS system with automated …


Investigating The Effects Of Fly Ash On The Properties Of Silica-Deficient High Alumina Materials, Sai Akshay Ponduru Jan 2025

Investigating The Effects Of Fly Ash On The Properties Of Silica-Deficient High Alumina Materials, Sai Akshay Ponduru

Doctoral Dissertations

This research is made up of five studies mainly focused on attaining sustainability in high alumina cements like calcium aluminate cement (CAC) and calcium sulfoaluminate belite cements (CSAB) by partially replacing them with additives and supplementary cementitious materials (SCMs) like fly ash (FA). The first study focused on understanding the reaction kinetics of CAC and FA binders at different replacement levels (i.e. between 10%-to-50% by mass) and their effect on mechanical properties. It was also shown that the reactive nature of FAs can be determined by calculating a single parameter called number of constraints (nc) derived from topological constraint theory. …


Drone-Based Multimodal Sensing On Vegetations And Data Analytics For Early Detection Of Gas Leakage From Underground Pipelines, Pengfei Ma Jan 2025

Drone-Based Multimodal Sensing On Vegetations And Data Analytics For Early Detection Of Gas Leakage From Underground Pipelines, Pengfei Ma

Doctoral Dissertations

"This study explored the feasibility of using multimodal remote sensors in the early detection of natural gas leaks from underground pipelines, as vegetation situated above pipelines can discern microbial changes in soil when affected by gas and exhibit physiological stress symptoms on leaves. Three sensors (RBG, thermal, and hyperspectral cameras) were utilized to monitor vegetation stress as an indicator of gas leaks. A laboratory experiment was conducted to evaluate the workability of vegetation for gas leak detection. Regular hyperspectral imagery was collected from test vegetations to identify gas stress and distinguish it from other environmental stressors such as salinity impact, …


Nmr Relaxometry Approach For The Detection Of Asphalt Binder Performance Properties, Rebecca Herndon Jan 2025

Nmr Relaxometry Approach For The Detection Of Asphalt Binder Performance Properties, Rebecca Herndon

Doctoral Dissertations

"Asphalt is a necessary material for transportation infrastructure. Understanding the material properties of asphalt binders is critical for improving infrastructure and enhancing the lifetime of pavements. While the physical properties of asphalt binders are well-defined by standard procedures and parameters, the chemical environment lacks definition. Physical parameters like viscosity and stiffness are traditionally used to differentiate asphalt binders, describe aging, and indicate the impact of additives. However, these tests have limited insight into the material's chemical environment. Therefore, a nondestructive analytical technique, nuclear magnetic resonance (NMR) relaxometry, was employed to investigate the chemical environment of asphalt binders. Although NMR relaxometry …


Characterization And Modeling Of Properties Of Unsaturated And Partially Damaged Cement-Based Materials, Rezwana Binte Hafiz Jan 2025

Characterization And Modeling Of Properties Of Unsaturated And Partially Damaged Cement-Based Materials, Rezwana Binte Hafiz

Doctoral Dissertations

"Transport properties, governing the resistance of cement-based materials to harmful substances are essential considerations for long-term performance. This study addressed the often-overlooked dimension of transport properties in unsaturated cement-based materials, crucial as most concrete structures face variable environmental conditions, leading to partial saturation. A two-scale model was introduced, enhancing our comprehension of transport properties in conditions reflecting real-world scenarios. Empirical correlation representing bulk paste characteristics was established, facilitating the upscaling of properties to mortar and concrete. The model was extended to predict the transport properties of mortar as well.

Environmental factors can contribute to the degradation of cement-based materials, with …


Characterizations Of Eco-Friendly Class C Fly Ash-Based Alkali-Activated Mixtures For Various 3d-Printing Techniques, Fareh Abudawaba Jan 2025

Characterizations Of Eco-Friendly Class C Fly Ash-Based Alkali-Activated Mixtures For Various 3d-Printing Techniques, Fareh Abudawaba

Doctoral Dissertations

This study explored the potential of using high-calcium class C fly ash (FA) as the main precursor for synthesizing alkali-activated mortar (AAM) suitable for 3D-printed concrete (3DPC) applications. The objective was to broaden the selection of AAMs, designed to suit various printing techniques, including continuous mixing and pumping, large batch mixing, and set-on-demand processes. The study began by assessing the fresh properties of various mixtures, utilizing tests such as open time (OT), initial setting time (IST), immediate axial deformation, and penetration test (PT), to determine the mixtures' extrudability and buildability. The study optimized mixtures with a broad spectrum of cycle …


2024 Scholarly Productivity Report, Missouri University Of Science And Technology Dec 2024

2024 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.


Harmonizing Vaccine And Infrastructure Development To Tame Cholera Outbreaks Across Africa, Amira Mohamed Taha, Hussam Mahmoud, Emad M. Hassan, Mohamed M. Ghonaim Dec 2024

Harmonizing Vaccine And Infrastructure Development To Tame Cholera Outbreaks Across Africa, Amira Mohamed Taha, Hussam Mahmoud, Emad M. Hassan, Mohamed M. Ghonaim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Vaccines and clean water shortages continue to give rise to cholera outbreaks in Africa. Coordinated efforts to increase vaccine distribution and improve physical infrastructure are needed while considering future outbreaks and water demands due to conflicts and climate events.


Thermal Conductivity Characterization Of High Oleic Vegetable Oils Based Hybrid Nanofluids Formulated Using Gnp, Tio2, Mos2, Al2o3 Nanoparticles For Mql Machining, Anthony Chukwujekwu Okafor, Tobechukwu Kingsley Abor, Saidanvar Esanjonovich Valiev, Ignatius Echezona Ekengwu, Abiodun Saka, Monday Uchenna Okoronkwo Dec 2024

Thermal Conductivity Characterization Of High Oleic Vegetable Oils Based Hybrid Nanofluids Formulated Using Gnp, Tio2, Mos2, Al2o3 Nanoparticles For Mql Machining, Anthony Chukwujekwu Okafor, Tobechukwu Kingsley Abor, Saidanvar Esanjonovich Valiev, Ignatius Echezona Ekengwu, Abiodun Saka, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper presents the results of thermal conductivity characterization of six high oleic soybean oil (HOSO) and four high oleic canola oil (HOCO)-Based hybrid nanofluids formulated with four types of nanoparticles (Graphene nanoplatelet (xGnP), TiO2, MoS2, and Al2O3) at nanoparticles wt.% concentration from 1 % to 7 % in 1 % increment using the two-step method for use in MQL machining of difficult-to-cut metals. Thermal conductivity of the formulated hybrid nanofluids were measured using Thermtest Transient Hot Wire Liquid Thermal Conductivity Meter at temperatures from 25 °C to 75 °C in increment …


A Strategic Insight Into The Market For Carbon Management Capacity, Mahelet G. Fikru, Ting Shen, Jennifer Brodmann, Hongyan Ma Dec 2024

A Strategic Insight Into The Market For Carbon Management Capacity, Mahelet G. Fikru, Ting Shen, Jennifer Brodmann, Hongyan Ma

Economics Faculty Research & Creative Works

This study presents the market for carbon management capacity via carbon capture, utilization, and storage technologies, identifying demand and supply forces, as well as clarifying the potential impact of market and non-market-based shocks on technology developers versus adopters. The paper addresses a prevailing gap in market analysis, introducing a microeconomic framework and unique dataset to identify key players, market forces, and policy incentives shaping the carbon capture, utilization, and storage landscape. The analysis equips industry stakeholders, policymakers, and investors with valuable insights regarding (1) leaders in the design, development, and manufacture of carbon capture, utilization, and storage technologies (supply), (2) …


Fitting Quality Of Nmr Relaxation Data To Differentiate Asphalt Binders, Rebecca M. Herndon, Kevin Lai, Magdy Abdelrahman, Klaus Woelk Dec 2024

Fitting Quality Of Nmr Relaxation Data To Differentiate Asphalt Binders, Rebecca M. Herndon, Kevin Lai, Magdy Abdelrahman, Klaus Woelk

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder performance grades (PGs) are important metrics in designing pavements for effective transportation infrastructure. the PG system relies on the binder's stiffness and is determined through energy- and time-intensive physical testing. Physical properties, like stiffness, can also be determined by spin–lattice NMR relaxometry, a non-destructive chemical method. NMR relaxometry can quantify the molecular mobility of materials by determining relaxation times from exponential decays of excited nuclear magnetization. While relaxation times have been used to determine physical properties of materials, a quantitative relation to the PG grades of asphalt binder is yet to be established. in this study, T1 NMR …


Assessing The Critical Factors Influencing Worker Safety In Roadway Work Zones, Bahaa Chammout, Muaz O. Ahmed, Islam El-Adaway Dec 2024

Assessing The Critical Factors Influencing Worker Safety In Roadway Work Zones, Bahaa Chammout, Muaz O. Ahmed, Islam El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Ongoing roadway construction and maintenance activities are essential for sustaining and improving infrastructure. Nonetheless, work zones in the United States continue to experience concerning frequencies of occupational and traffic accidents. Previous research highlighted multiple factors influencing work zone safety, yet their relative impact and importance remain unclear. This study addresses this gap following a multistep methodology. First, 32 safety factors were identified through an extensive literature review in a previous study. Second, a survey was administered among 298 professionals from diverse backgrounds, with an average of 17.75 years of construction experience and 13.78 years of work zone experience, to assess …


Thermal Conductivity Characterization Of High Oleic Vegetable Oils Based Hybrid Nanofluids Formulated Using Gnp, Tio2, Mos2, Al2o3 Nanoparticles For Mql Machining, Anthony Chukwujekwu Okafor, Tobechukwu Kingsley Abor, Saidanvar Esanjonovich Valiev, Ignatius Echezona Ekengwu, Abiodun Saka, Monday Uchenna Okoronkwo Dec 2024

Thermal Conductivity Characterization Of High Oleic Vegetable Oils Based Hybrid Nanofluids Formulated Using Gnp, Tio2, Mos2, Al2o3 Nanoparticles For Mql Machining, Anthony Chukwujekwu Okafor, Tobechukwu Kingsley Abor, Saidanvar Esanjonovich Valiev, Ignatius Echezona Ekengwu, Abiodun Saka, Monday Uchenna Okoronkwo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents the results of thermal conductivity characterization of six high oleic soybean oil (HOSO) and four high oleic canola oil (HOCO)-based hybrid nanofluids formulated with four types of nanoparticles (Graphene nanoplatelet (xGnP), TiO2, MoS2, and Al2O3) at nanoparticles wt.% concentration from 1 % to 7 % in 1 % increment using the two-step method for use in MQL machining of difficult-to-cut metals. Thermal conductivity of the formulated hybrid nanofluids were measured using Thermtest Transient Hot Wire Liquid Thermal Conductivity Meter at temperatures from 25 °C to 75 °C in increment of 10 °C. Obtained results showed that thermal …


Final Report - Qa/Qc Guidelines On Drone-Based Remote Sensing For Bridge Element Inspection, Genda Chen, Woubishet Z. Taffese, Ritesh Sharma, Zhenhua Shi Nov 2024

Final Report - Qa/Qc Guidelines On Drone-Based Remote Sensing For Bridge Element Inspection, Genda Chen, Woubishet Z. Taffese, Ritesh Sharma, Zhenhua Shi

Project IM-4

Remote sensing of elevated infrastructure via robotic platforms has recently gained increasing interest in bridge inspection. Such automated bridge inspection can not only overcome accessibility and safety challenges but also improve objectivity and consistency of the measured data compared to current visual inspection practices. With the advent of advanced technologies, quality assurance (QA) and quality control (QC) for robot-based bridge inspection become imperative. This study aims (1) to understand actionable inspection activities and procedures in route planning, sensor preparation and measurement, ground truth selection, and statistical analysis; (2) to outline assessment matrices and best practices for drone-based images to achieve …


Energetics Of Mode-1 Internal Waves Interacting With Topographic Ridges Of Varying Height And Slope, Matthew R. Klema, Subhas K. Venayagamoorthy Nov 2024

Energetics Of Mode-1 Internal Waves Interacting With Topographic Ridges Of Varying Height And Slope, Matthew R. Klema, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Energetics of mode-1 internal waves interacting with topographic ridges are investigated using high-resolution two-dimensional simulations at spatial scales of m that span between classical laboratory-scale (m) and field-scale simulations (m). This paper focuses on the energetics of wave-Topography interaction, with emphasis on systematically examining the partitioning of the incident wave energy as a function of wave forcing and topographic parameters. Partitioning of energy into the transmitted, reflected and dissipated components is quantified as a function of wave Froude number (velocity amplitude of forcing and internal wave celerity), slope criticality, where topographic slope and wave characteristic slope, and the ratio of …


Enhancing Frp-Concrete Interface Bearing Capacity Prediction With Explainable Machine Learning: A Feature Engineering Approach And Shap Analysis, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen Nov 2024

Enhancing Frp-Concrete Interface Bearing Capacity Prediction With Explainable Machine Learning: A Feature Engineering Approach And Shap Analysis, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study introduces a novel approach to predict the shear bearing capacity of FRP-concrete interfaces using explainable machine learning. Eight algorithms are employed: three standalone models (Artificial Neural Network, Support Vector Regression, and Decision Tree) and five ensemble learning models (Bagging, Random Forest, Adaptive Boosting, Gradient Boosting, and Extreme Gradient Boosting). Four scenarios with varying input features, including engineered features inspired by mechanics-based bearing capacity equations, are examined. Notably, the inclusion of engineered features such as the stiffness of the FRP strip (Kf) significantly enhanced prediction accuracy and efficiency, although the width correction coefficient (bf/bc) did not yield significant benefits, …


Three-Dimensional Technique For Accurate Pavement Macrotexture Measurement Using Surface Volume Parameters, Alireza Pourhassan, Ahmed A. Gheni, Mohamed A. Elgawady Nov 2024

Three-Dimensional Technique For Accurate Pavement Macrotexture Measurement Using Surface Volume Parameters, Alireza Pourhassan, Ahmed A. Gheni, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study introduces a novel three-dimensional (3D) pavement macrotexture measurement technique using ISO 25178 Surface Volume Parameters (SVP). The method calculates pavement material volume and texture height using cutoff thresholds based on the cumulative probability density function of measured heights. The research aims to optimize these cutoff thresholds for accurate 3D analysis of pavement macrotexture. The study evaluates the performance of various 3D and 2D parameters—assessing their repeatability, reliability, and accuracy—across thirty pavement samples with diverse macrotexture conditions. Findings show that the 3D SVP method, with optimized cutoff thresholds, strongly correlates with sand patch mean texture depth (MTD) and exhibits …


Human-Centered Approach For Resilience Assessment Of Healthcare Networks Subjected To Sequential Earthquakes, Emad Hassan, Hussam Mahmoud Nov 2024

Human-Centered Approach For Resilience Assessment Of Healthcare Networks Subjected To Sequential Earthquakes, Emad Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Healthcare services are critical for community resilience and stability as their role after disastrous events is indispensable to reducing casualties and returning the community to normalcy. Sequential mainshock-aftershock events can damage hospital components, reduce utility availability, and cause multiple patient surges. No studies have been conducted to evaluate the impact of mainshock-aftershock events on healthcare resilience. Accordingly, here we investigate the impact of multiple earthquakes on the healthcare network in Shelby County, Tennessee, and determine the optimal resources needed to enhance its functionality. The functionality is estimated by combining functionality quantity and quality terms. The quantity is calculated based on …


The Effects Of Wildfires On The Mental And Physical Health Of School-Age Children In North America: A Scoping Review, Sarah Oerther, Sarah Manspeaker, Alison Wix, Daniel Oerther, Carmen Marsit Nov 2024

The Effects Of Wildfires On The Mental And Physical Health Of School-Age Children In North America: A Scoping Review, Sarah Oerther, Sarah Manspeaker, Alison Wix, Daniel Oerther, Carmen Marsit

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Background: Wildfires are occurring more often and with greater intensity, leading to longer and harsher fire seasons. As a result, children are more frequently exposed to wildfire smoke, which increases their risk of mental and physical health effects. Purpose: The purpose of our scoping review is to explore the current literature on what is known about the direct and indirect impacts of wildfires on the mental and physical health of school-age children in North America (5 to 18-year-olds). Methods: A health sciences librarian-assisted literature search, with input from the research team, was performed. Results: A total of 16 studies were …


Anti-Corrosion Performance Of Magnesium Potassium Phosphate Cement Coating On Steel Reinforcement: The Effect Of Boric Acid, Fan Zhang, Jihui Qin, Kangyi Cai, John J. Myers, Hongyan Ma Nov 2024

Anti-Corrosion Performance Of Magnesium Potassium Phosphate Cement Coating On Steel Reinforcement: The Effect Of Boric Acid, Fan Zhang, Jihui Qin, Kangyi Cai, John J. Myers, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It has recently been found that magnesium potassium phosphate cement (MKPC) paste coating applied on the surface of steel reinforcement can effectively retard the onset of corrosion and suppress corrosion reactions. However, the fast-setting nature of MKPC—which is a merit in repair—can be problematic in a practical engineering process of coating the steel reinforcement with MKPC paste. To address this problem, boric acid (H3BO3) was added as a retarder in an MKPC formulation to prolong the setting time. This work investigated the impact of boric acid (at 5% by weight of MgO) on the anti-corrosion performance …


Circular Economy Integration In Leed: A Decade Of Materials And Resources Credit Achievement Patterns, Radwa Eissa, Islam H. El-Adaway Nov 2024

Circular Economy Integration In Leed: A Decade Of Materials And Resources Credit Achievement Patterns, Radwa Eissa, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Previous studies consistently label the Materials and Resources (MR) credit category of the Leadership in Energy and Environmental Design (LEED) as the least attainable, despite its critical role in transitioning to a circular economy (CE). To this end, a long-standing gap exists in understanding the MR credit achievement, especially in LEED v4, which has been in use for nearly over a decade. This paper evaluates the level of CE integration in LEED v4 across 971 US-based certified projects. The study comprehensively analyzed the projects achievement patterns of the five MR credits: Building Life Cycle Impact Reduction (C1), Environmental Product Declarations …


Semi-Annual Progress Report #15, Missouri University Of Science And Technology Oct 2024

Semi-Annual Progress Report #15, Missouri University Of Science And Technology

Semi-Annual Progress Reports

No abstract provided.


2017-2024 Emerging Technologies And Milestone Achievements Toward Automated Bridge Inspection And Maintenance, Genda Chen Oct 2024

2017-2024 Emerging Technologies And Milestone Achievements Toward Automated Bridge Inspection And Maintenance, Genda Chen

INSPIRE Archived Webinars

Main hardware and software systems developed in the INSPIRE University Transportation Center from 2017 to 2024 will be presented. Their characteristic parameters, operation procedures, performance metrics, advantages over the state of practice, and application limitations will be summarized. These systems include, but not limited to,

 Flying and climbing robots for high-quality data collection from remote sensing and nondestructive testing,

 Explainable artificial intelligence and machine learning for element segmentation and defect classification,

 3D reconstruction and digital twins for virtual inspection,

 Framework for the probability of detection for various defects and damage from in-situ sensors,

 Defect detection, …


Improving Mechanical Properties Of Magnesium Phosphate Cement-Based Ultra-High Performance Concrete By Ultrafine Fly Ash Incorporation, Jihui Qin, Zhichao Zhang, Hongyan Ma, Xiaobing Dai, Xing Cheng, Xingwen Jia, Jueshi Qian Oct 2024

Improving Mechanical Properties Of Magnesium Phosphate Cement-Based Ultra-High Performance Concrete By Ultrafine Fly Ash Incorporation, Jihui Qin, Zhichao Zhang, Hongyan Ma, Xiaobing Dai, Xing Cheng, Xingwen Jia, Jueshi Qian

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Magnesium phosphate cement-based ultra-high-performance concrete (MPC-UHPC) develops strength rapidly but shows unsatisfactory ultimate strength (<150 >MPa). In this study, ultrafine fly ash (UFA) was incorporated in MPC-UHPC to improve mechanical properties. The effect of UFA content, varying from 0 % to 15 %, by weight of binder, on microstructure, fiber pullout behavior, mechanical strengths, flexural and tensile properties of MPC-UHPC reinforced with 2 vol% steel fibers was investigated. Experimental results indicate that the incorporation of 10 %–15 % UFA with mean particle size of 1.4 µm was effective in reducing porosity and microcracks of binder matrix and fiber–matrix interface, thereby …


Novel Insights On The Setting Process, Hardened Properties, And Durability Of Sustainable Ultra-High-Performance Seawater Sea Sand Concrete, Wei Zhang, Dawei Ding, Jianxing Sun, Feng Guo, Haibao Feng, Hongyan Ma, Shuxian Hong, Biqin Dong, Dongshuai Hou Oct 2024

Novel Insights On The Setting Process, Hardened Properties, And Durability Of Sustainable Ultra-High-Performance Seawater Sea Sand Concrete, Wei Zhang, Dawei Ding, Jianxing Sun, Feng Guo, Haibao Feng, Hongyan Ma, Shuxian Hong, Biqin Dong, Dongshuai Hou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Using seawater and sea sand to prepare concrete could effectively alleviate the shortage of freshwater and river sand resources and promote the sustainable development of concrete. However, the current research on the setting process, hardened properties, and sustainability of ultra-high-performance seawater sea sand concrete (UHPSSC) remain considerably limited. In this paper, the UHPSSC was designed to mitigate the autogenous shrinkage and enhance the sustainability, and the effect of seawater, untreated and desalinated sea sand on the setting process, mechanical properties, durability, and sustainability was explored by various tests. Results show that the abundant ions (e.g., Cl- and SO42-) in seawater …


On The Turbulent Viscosity Parameter Cμ In The K–Ε Model, Harshit Mishra, Subhas Karan Venayagamoorthy Oct 2024

On The Turbulent Viscosity Parameter Cμ In The K–Ε Model, Harshit Mishra, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Reynolds-averaged Navier–Stokes (RANS) models depend on empirical constants to close the Reynolds stress terms. The empirical constants were obtained using experiments conducted at low Reynolds numbers several decades ago. In this paper, we revisit the turbulent viscosity parameter Cμ, based on the stress–intensity ratio c2 = |uw|/k. Here, |uw| and k are the absolute values of the Reynolds stress and turbulent kinetic energy, respectively. Through a priori comparisons, we find that the currently accepted value of Cμ = 0.09 does not agree with the latest direct numerical simulation (DNS) and experimental datasets of wall-bounded turbulent planar flows. Therefore, …


Pozzolanic Reactivity Of Carbonated High-Calcium Fly Ash: A Mechanism Study, Gao Deng, Nannan Zhang, Wenyu Liao, Hongyan Ma, Yongjia He, Linnu Lu, Lingyu Chi Oct 2024

Pozzolanic Reactivity Of Carbonated High-Calcium Fly Ash: A Mechanism Study, Gao Deng, Nannan Zhang, Wenyu Liao, Hongyan Ma, Yongjia He, Linnu Lu, Lingyu Chi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This research investigates the impact of accelerated carbonation treatment on the pozzolanic reactivity of high-calcium fly ash (HFA) by monitoring the reaction heat of HFA/carbonated HFA (CFA)-calcium hydroxide (CH) blends and elucidates the underlying factors influencing the pozzolanic reactivity. The results indicate that in HFA/CFA-CH blends, CFA exhibits a comparable pozzolanic reactivity to that of HFA. This is attributed to the carbonation products accelerating the formation of MonoCarb aluminate (main) and C-S-H, compensating for the reduced heat resulting from the diminished highly reactive components after the carbonation treatment. Additionally, the increased surface area due to carbonation treatment is favorable for …


Performance Of Project Delivery Methods For Us Airport Projects: A Holistic Quantitative Risk-Based Assessment Through Perceptions Of Associated Industry Experts, Ramy Khalef, Islam H. El-Adaway Oct 2024

Performance Of Project Delivery Methods For Us Airport Projects: A Holistic Quantitative Risk-Based Assessment Through Perceptions Of Associated Industry Experts, Ramy Khalef, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The aviation sector received an underperforming D+ score, indicating its deteriorating qualities in comparison with the overall US infrastructure. In response, US governmental bodies issued investment bills that target the improvement of the nation's airport system. Airport projects are still being implemented through design-bid-build (DBB), which is notorious for its ineffective risk shift, low contractor input, and poor cost and schedule performance. Studies show that design-build (DB) possesses prospective cost and schedule benefits. Despite this, there is still reluctance toward DB's usage in airport projects. Moreover, current studies lack in offering frameworks that assist airport practitioners in guiding stakeholders toward …