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Full-Text Articles in Engineering

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, …


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 …


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 …


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 …


Environmental Engineering 3.0: Faced With Planetary Problems, Solutions Must Scale-Up Caring, Daniel B. Oerther, Sarah Oerther, Linda A. Mccauley Sep 2024

Environmental Engineering 3.0: Faced With Planetary Problems, Solutions Must Scale-Up Caring, Daniel B. Oerther, Sarah Oerther, Linda A. Mccauley

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal.


Quantitative Assessment Of The Architect's Role Under Us Standard Construction Contracts: A Graph Theory Approach, Mariam Elazhary, Ahmed Shiha, Islam H. El-Adaway, Sammi Young Sep 2024

Quantitative Assessment Of The Architect's Role Under Us Standard Construction Contracts: A Graph Theory Approach, Mariam Elazhary, Ahmed Shiha, Islam H. El-Adaway, Sammi Young

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Evaluating the Architect's Role in Construction Contracts is Vital for Improving the Contractual Relationship and Preventing Disputes. Standard Contracts Define the Architect as an Owner's Agent And/or a Contract Administrator. Studies Often Use Qualitative and Subjective Evaluations to Analyze the Architect's Role. However, there is a Lack of Quantitative Measures that Objectively Evaluate the Architect's Capacities in Construction Contracts. This Paper Fills This Knowledge Gap. This Study Proposes a Quantitative Graph Theory-Based Approach to Analyze the Architect's Roles under Three Standard Forms of Construction Contracts in the US: (1) Extracting and Classifying Party Interactions; (2) Modeling the Interactions using Network …


The Role Of The Metaverse In Transforming The Management Skill Set Of Construction Practitioners, Ali M. Saad, Islam H. El-Adaway Sep 2024

The Role Of The Metaverse In Transforming The Management Skill Set Of Construction Practitioners, Ali M. Saad, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Reduction In Scc Form Pressure Through In-Situ Co2 Mineralization, Sean Monkman, Soo Duck Hwang, Kamal Khayat Sep 2024

Reduction In Scc Form Pressure Through In-Situ Co2 Mineralization, Sean Monkman, Soo Duck Hwang, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

One challenge of using self-consolidating concrete (SCC) for cast-in-place structural applications is that the rheological properties of the concrete (low yield stress and low plastic viscosity) can lead to increased lateral pressure exerted on the formwork. High structural build up and thixotropy can reduce the lateral pressure, thereby allowing for simpler formwork and faster construction. The addition of CO2 to SCC, in proportions from 0.063 % to 0.250 %, by weight of cement, was investigated as a rheology modifier. The CO2 served to increase the plastic viscosity with little impact on the dynamic yield stress up to a …


Price Escalation In Construction Projects: Examining National And International Contracts, Bahaa Chammout, Islam H. El-Adaway, Mohammad Abdul Nabi, Rayan H. Assaad Sep 2024

Price Escalation In Construction Projects: Examining National And International Contracts, Bahaa Chammout, Islam H. El-Adaway, Mohammad Abdul Nabi, Rayan H. Assaad

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The construction industry has witnessed unprecedented disruptions in the supply chain (SC) over the past four years due to the consecutive impacts of the 2018 steel and aluminum tariffs, the COVID-19 pandemic, and the Russian-Ukrainian war. SC disruptions have been linked to price escalations, the management of which varies across different construction contracts. Thus, there is a timely need to understand the contractual implications of price escalation clauses. This article fulfills this research requirement by following an interdependent research methodology. First, the authors analyzed and compared price escalation provisions under various US-based, international, and UK-based standard design-bid-build contracts. Second, the …


Forecasting Construction Material Prices Using Macroeconomic Indicators Of Trading Partners, Ahmed Shiha, Islam H. El-Adaway Sep 2024

Forecasting Construction Material Prices Using Macroeconomic Indicators Of Trading Partners, Ahmed Shiha, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Supply chain instabilities and inflated material prices have had a disruptive impact on cost estimating of construction projects. While several research efforts used national macroeconomic indicators to forecast the prices of domestically produced construction materials, none of the existing studies investigated whether the lagged macroeconomic indicators of the main trading partners could enhance the predictability of the prices of cement, steel, and lumber in the US construction sector. This paper fills this knowledge gap. The authors adopted a multi-step methodology that included: (1) collecting data on the target variables and the candidate leading indicators; (2) identifying the structural breaks in …


Molecular Dynamics Simulation Insights Into Rejuvenating Aged Asphalt With Waste Soybean Oil And Polymers, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang Aug 2024

Molecular Dynamics Simulation Insights Into Rejuvenating Aged Asphalt With Waste Soybean Oil And Polymers, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study utilized molecular dynamics simulations to assess the rejuvenation of aged asphalt (AA) with waste soybean oil (WSO) and functionalized SBS polymers, focusing on: 1) constructing and validating models for virgin asphalt (VA), AA, and composite rejuvenated asphalt with WSO and polymers; 2) analyzing diffusion effects and binding abilities in these rejuvenated models; 3) evaluating interface binding and diffusion behaviors in composite rejuvenated models. The addition of functionalized SBS molecules and WSO improved the diffusion rates of various components within these models. Specifically, functionalized linear-SBS (LSBS) molecules demonstrated superior diffusion performance compared to star-SBS (SSBS) molecules. Incorporating WSO and …


Investigation Of The Cohesive Behavior Of Water-Intervened Rejuvenated Sbs-Modified Bitumen, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang Aug 2024

Investigation Of The Cohesive Behavior Of Water-Intervened Rejuvenated Sbs-Modified Bitumen, Ke Shi, Feng Ma, Zhen Fu, Jenny Liu, Ruimeng Song, Dongdong Yuan, Yujie Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

When water interacts with bitumen, the diffusion and cohesion characteristics between the components of bitumen are negatively impacted. Molecular dynamics simulations were employed to construct various bitumen models, including bitumen–bitumen (without water), water-containing single bitumen, water-containing bitumen–bitumen, and bitumen–water–bitumen models. The primary research objectives were as follows: comparing the changes in the densities of bitumen models with and without water, analyzing the interlayer cohesive energies of bitumen models interacting with water, evaluating the hydrogen bonds in water-containing bitumen models, and characterizing the diffusion behaviors of bitumen components. The results indicated that when water interacted with the bitumen, it filled internal …


Effect Of Superabsorbent Polymer On 3d Printing Characteristics As Rheology-Modified Agent, Yu Cun Gu, Kamal H. Khayat Aug 2024

Effect Of Superabsorbent Polymer On 3d Printing Characteristics As Rheology-Modified Agent, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to investigate the effects of two superabsorbent polymer (SAP) types, S1 and S2 (with continual absorption and rapid desorption, respectively) as rheology-modified agent on 3D printing characteristics. Three base mixtures were selected with different thixotropic behaviors (i.e., mixtures with high re-flocculation (τfloc), high structuration rate (Athix), and both low τfloc and Athix, respectively). The initial mini-slump flow of 190±10 mm was secured by adjusting superplasticizer (SP) or water demand (increasing w/b by either 0.025 or 0.05). An extrudable region was determined within the range of τfloc (200-890 Pa) and Athix (15-60 Pa/min). The use of the S2 …


Coupled Effect Of Fiber Type And Reinforcement Ratio On Flexural Behavior Of Reinforced Beams Cast With Super Workable Concrete, Jingjie Wei, Le Teng, Kamal H. Khayat Aug 2024

Coupled Effect Of Fiber Type And Reinforcement Ratio On Flexural Behavior Of Reinforced Beams Cast With Super Workable Concrete, Jingjie Wei, Le Teng, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigated the effect of 5-dimensional hooked-end fiber (5D) on the structural performance of beams and compared its efficiency with other fibers in strengthening structural performance of reinforced concrete (RC) beams with an increase in reinforcement ratio (ρ). The potential of using fibers to reduce the longitudinal rebar based on various design criteria was investigated. The fibers included 5D, a combination of 80 % 3-dimensional hooked-end and 20 % short steel fibers (STST), and two combinations of macro synthetic fibers A and B (MSF). Experimental results indicated that, compared to non-fibrous beams, using 5D was the most efficient in …


Extrudability Window And Offline Test Methods To Predict Buildability Of 3d Printing Concrete, Yu Cun Gu, Kamal H. Khayat Aug 2024

Extrudability Window And Offline Test Methods To Predict Buildability Of 3d Printing Concrete, Yu Cun Gu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Study Investigates the Effect of Thixotropy and Stiffness Evolution on the Extrudability and Buildability of 3D Printing Concrete. Different Types of Supplementary Cementitious Materials and Limestone Filler Were Used to Prepare Mortars with Varying Levels of Thixotropy and Early-Age Stiffness. Mixtures with Yield Stress and Flocculation (Τfloc) of 180–400 and 420–950 Pa, Respectively, Exhibited Adequate Extrudability Without Plastic Collapse. the Printing Was Completed 8–15 Min after Mixing at a Vertical Build-Up Rate of 138 Mm/min. Several Process Parameters, Including Rest Time to Secure a Penetration Resistance of 150 KPa (T150) and Penetration Resistance at Various Rest Times Were Developed …


Quantifying The Impact Of Technology Utilization On Schedule And Cost Performance In Construction Projects, Fareed Salih, Islam H. El-Adaway Aug 2024

Quantifying The Impact Of Technology Utilization On Schedule And Cost Performance In Construction Projects, Fareed Salih, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

There Has Been a Plethora of Research on the Performance of Schedule and Cost in Construction Projects. However, Current Research Falls Short in Investigating the Combined Contribution of Different Construction Technologies on Project Performance Metrics. Specifically, None of the Previous Efforts Have Used Integrated Earned Value Management (EVM) Parameters and Utilized Construction Technologies to Assess Project Schedule and Cost Performance. This Paper Fills This Knowledge Gap. to This End, a Multistep Research Methodology Was Employed to (1) Explore the Utilization Ratings of 13 Construction Technologies based on Data Collected from 52 Industry Experts; (2) Rank These Technologies in Terms of …


Accelerating The Circular Economy Transition: A Construction Value Chain-Structured Portfolio Of Strategies And Implementation Insights, Radwa Eissa, Islam H. El-Adaway Aug 2024

Accelerating The Circular Economy Transition: A Construction Value Chain-Structured Portfolio Of Strategies And Implementation Insights, Radwa Eissa, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Despite the Increasing Recognition of the Potential of Circular Economy (CE) Strategies, their Effective Application to Decarbonize the Construction Value Chain Faces Multiple Challenges. Ambiguity Surrounding CE, stemming from a Lack of Clarity on Actionable Strategies, is a Common Concern. Existing Studies Lack a Holistic Approach for Systematically Integrating CE Principles throughout the Construction Value Chain, resulting in a Scarcity of Information on How to Practically Adopt CE within Projects. This Research Aims to Accelerate CE Adoption by Creating a Value Chain-Structured Portfolio of CE Strategies and Analyzing the Implementation of Such Strategies in Actual Projects. to This End, a …


Rheology Modification Of Flowable Mortar With Co2, Sean Monkman, Soo Duck Hwang, Kamal Khayat Aug 2024

Rheology Modification Of Flowable Mortar With Co2, Sean Monkman, Soo Duck Hwang, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Rheological Properties of Mortar Samples with Different Additions of CO2 during Mixing Were Determined. Flowable Cement-Based Mortars at Three Different W/c (0.55, 0.45 and 0.35) Were Produced and the Effects of CO2 Gas Were Examined on the Fresh Properties of Slump Flow, Yield Stress and Plastic Viscosity. According to the Experimental Results, the Mortar Yield Stress and Plastic Viscosity Increased Faster over Time Than in a Reference System with the Increasing Addition of CO2 and Greater Effects Were Seen at the Lowest W/c of 0.35 Than at the Others. the Impact of the CO2 on …


The Effectiveness Of Waste Tire Pyrolysis Oils (Wtpos) As Rejuvenating Agents For Asphalt Materials, Ahmed S. El-Ashwah, Magdy Abdelrahman Aug 2024

The Effectiveness Of Waste Tire Pyrolysis Oils (Wtpos) As Rejuvenating Agents For Asphalt Materials, Ahmed S. El-Ashwah, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The continuous increase in solid waste materials, such as waste tires, underscores the critical importance of recycling them to mitigate environmental impact and promote sustainable resource management. This research study evaluated the effectiveness of utilizing waste tire pyrolysis oils (WTPOs) as recycling agents for asphalt materials. The chemical composition and thermal behavior of WTPO were analyzed using Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). Mechanically, the prepared WTPO binders were assessed by measuring dynamic viscosity and changes in high- and intermediate-temperature performance grades. Additionally, the cracking susceptibility of the binders was evaluated using the Glover-Rowe (G-R) parameter. The …


Indefinability Of Effective Stress For Unsaturated Soils, Xiong Zhang, Sandra Houston Aug 2024

Indefinability Of Effective Stress For Unsaturated Soils, Xiong Zhang, Sandra Houston

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

For decades, researchers have searched for an unsaturated soil effective stress that performs analogously to effective stress for saturated soils and provides some simplifications over net stress and suction approaches. A recent debate is whether problems identified with unsaturated soil effective stress can be resolved via elastoplastic analyses. Effective stress equations are reviewed and categorized as being based on volume change, shear strength, yield, or degree of saturation. These equations are evaluated for consistency with saturated soil effective stress expectations using the Barcelona basic model (BBM), simplified into an integrated elastoplastic framework using the modified state surface approach (MSSA). Under …


Effect Of Absorption Kinetics Of Superabsorbent Polymers On Printability And Interlayer Bond Of 3d Printing Concrete, Yu Cun Gu, Shuyi Zheng, Hongyan Ma, Wu Jian Long, Kamal H. Khayat Aug 2024

Effect Of Absorption Kinetics Of Superabsorbent Polymers On Printability And Interlayer Bond Of 3d Printing Concrete, Yu Cun Gu, Shuyi Zheng, Hongyan Ma, Wu Jian Long, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study examines the effect of the material characteristics of superabsorbent polymers (SAPs) on the printability and interlayer bond strength of 3D printing concrete. Three types of SAP, including two acrylamide-co-acrylic polymers with coarse and fine particle sizes (S1 and S2) and an acrylic copolymer (S3), were employed. The investigated mortar mixtures had a fixed initial mini-slump flow of 195 ± 10 mm and yield stress of 290 ± 25 Pa. The fluidity of SAP-incorporated mortars was maintained by either adjusting the superplasticizer dosage or increasing the water content. Test results indicate that particle flocculation is dependent on SAP absorption …


Influence Of Aggregate Properties On Skid Resistance Of Pavement Surface Treatments, Alireza Roshan, Magdy Abdelrahman Aug 2024

Influence Of Aggregate Properties On Skid Resistance Of Pavement Surface Treatments, Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Skid resistance is a critical aspect for traffic safety since it significantly influences vehicle control and minimizes the distance required for emergency braking. The surface characteristics of pavements play a pivotal role in determining skid resistance. To achieve the optimal skid resistance performance, the pavement must sustain a specific level of friction. Thus, it is advantageous to apply surface treatments in areas that require enhanced friction. This study investigates the impact of factors such as the aggregate source, size, morphological properties, and abrasion levels on the skid resistance and frictional characteristics of a high-friction surface treatment (HFST). A complete investigation …


Development Of Multivariate-Coupled Grouting Diffusion Model For Rcc, Xiao Sun, Yao Wang, Hengrui Liu, Zhuanjia Yang, Hongyan Ma Jul 2024

Development Of Multivariate-Coupled Grouting Diffusion Model For Rcc, Xiao Sun, Yao Wang, Hengrui Liu, Zhuanjia Yang, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Grouting Quality of Grout-Enriched Roller Compacted Concrete (RCC) is Difficult to Be Quantified Due to the Fact that the Crucial Effects, Such as Infiltration and the Compaction of the Skeleton of the RCC, Are Not Taken into Consideration. Combined with Model Testing, This Study Proposes an Improved Grouting Prediction Model Which Considers the Coupling Effect of Pore Fractal Properties, Time Variation of Grout Rheological Properties and Infiltration. Moreover, the Influence of Construction Parameters Such as Grouting Parameters, Construction Period Selection, Grouting Pipe Arrangement on the Grouting Effect Was Clarified. the Tests Indicated that the Maximum Diffusion Range of Slurry …


Early Detection Of Pipeline Natural Gas Leakage From Hyperspectral Imaging By Vegetation Indicators And Deep Neural Networks, Pengfei Ma, Tarutal Ghosh Mondal, Zhenhua Shi, Mohammad Hossein Afsharmovahed, Kevin Romans, Liujun Li, Ying Zhuo, Genda Chen Jul 2024

Early Detection Of Pipeline Natural Gas Leakage From Hyperspectral Imaging By Vegetation Indicators And Deep Neural Networks, Pengfei Ma, Tarutal Ghosh Mondal, Zhenhua Shi, Mohammad Hossein Afsharmovahed, Kevin Romans, Liujun Li, Ying Zhuo, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The timely detection of underground natural gas (NG) leaks in pipeline transmission systems presents a promising opportunity for reducing the potential greenhouse gas (GHG) emission. However, existing techniques face notable limitations for prompt detection. This study explores the utility of Vegetation Indicators (VIs) to reflect vegetation health deterioration, thereby representing leak-induced stress. Despite the acknowledged potential of VIs, their sensitivity and separability remain understudied. In this study, we employed ground vegetation as biosensors for detecting methane emissions from underground pipelines. Hyperspectral imaging from vegetation was collected weekly at both plant and leaf scales over two months to facilitate stress detection …


Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation, Le Teng, Ming Jin, Jiadi Du, Kamal H. Khayat Jul 2024

Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation, Le Teng, Ming Jin, Jiadi Du, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Thin bonded ultra-high-performance concrete (UHPC) overlay is an advanced technology for bridge deck rehabilitation. UHPC should be tailored to secure adequate flowability and high thixotropy to facilitate mixing and placement with a low risk of sagging of the material on sloped bridge deck surfaces. The synergetic effect between nano clay (NC) and polycarboxylate ether (PCE) superplasticizer or cellulose-based viscosity modifying admixture (VMA) and PCE on the rheological properties (yield stress, plastic viscosity, and thixotropy), cement hydration, autogenous shrinkage, compressive strength, and porosity was systematically investigated. The bond strength between conventional concrete (CC) representing existing bridge deck concrete and thixotropic UHPC …


Freezing-Thawing Hysteretic Behavior Of Soils, Jidong Teng, Antai Dong, Sheng Zhang, Xiong Zhang, Daichao Sheng Jul 2024

Freezing-Thawing Hysteretic Behavior Of Soils, Jidong Teng, Antai Dong, Sheng Zhang, Xiong Zhang, Daichao Sheng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The soil freezing characteristic curve (SFCC) plays a crucial role in investigating the soil freezing-thawing process. Due to the challenges associated with measuring the SFCC, there is a shortage of high-quality or rigorous test results with sufficient metadata to be effectively used for applications. Current researchers typically conduct freezing tests to measure the SFCC and assume a singular SFCC when studying the freezing-thawing process of soils, although limited studies indicated that there is a hysteresis during the freezing and thawing process. In this paper, a series of freezing-thawing tests were performed to assess the SFCC, utilizing a precise nuclear magnetic …


Experimental Study On The Detection Of The Existence And Location Of Mimicked And Unexpected Interface Debonding Defects In An Existing Rectangular Cfst Column With Pzt Materials, Qian Liu, Bin Xu, Genda Chen, Weilong Ni, Zhixun Liu, Chun Lin, Zhiyou Zhuang Jul 2024

Experimental Study On The Detection Of The Existence And Location Of Mimicked And Unexpected Interface Debonding Defects In An Existing Rectangular Cfst Column With Pzt Materials, Qian Liu, Bin Xu, Genda Chen, Weilong Ni, Zhixun Liu, Chun Lin, Zhiyou Zhuang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Interface bonding conditions between concrete and steel materials play key roles in ensuring the composite effect and load-carrying capacity of concrete–steel composite structures such as concrete-filled steel tube (CFST) members in practice. A method using both surface wave and electromechanical impedance (EMI) measurement for detecting the existence and the location of inaccessible interface debonding defects between the concrete core and steel tube in CFST members using piezoelectric lead zirconate titanate (PZT) patches as actuators and sensors is proposed. A rectangular CFST specimen with two artificially mimicked interface debonding defects was experimentally verified using PZT patches as the actuator and sensor. …


Rotational Rheometry Test Of Portland Cement-Based Materials – A Systematic Literature Review, Laura Silvestro, Artur Spat Ruviaro, Geannina Lima, Luís Urbano Durlo Tambara Júnior, Dimitri Feys, Ana Paula Kirchheim Jun 2024

Rotational Rheometry Test Of Portland Cement-Based Materials – A Systematic Literature Review, Laura Silvestro, Artur Spat Ruviaro, Geannina Lima, Luís Urbano Durlo Tambara Júnior, Dimitri Feys, Ana Paula Kirchheim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Study Systematically Reviews 62 Papers on the Use of Rotational Rheometry to Assess the Fresh State Behavior of Portland Cement-Based Materials. the Research Highlights the Wide Variation in Test Methods and Aims to Provide a Comprehensive overview. Findings Reveal that 50.0% of Studies Employed Vane Geometry, despite its Limitations in Providing Transformation Equations. Regarding Dynamic Shearing Tests, 67.0% Followed a Consensus using a Pre-Shearing Step and a Stepwise Routine with Stabilization Times ≥ 10 S. While the Bingham Model is Commonly Used, the Study Emphasizes the Importance of Considering Shear-Thinning Behavior in Cementitious Materials. Models Like Herschel-Bulkley and Modified …


Application Of Multidisciplinary Community Resilience Modeling To Reduce Disaster Risk: Building Back Better, Wanting "Lisa" Wang, John W. Van De Lindt, Blythe Johnston, P. Shane Crawford, Guirong Grace Yan, Thang Dao, Trung Do, Katie Skakel, Mojtaba Harati, Tu Nguyen, Robinson Umeike, Silvana Croope, Andre R. Barbosa Jun 2024

Application Of Multidisciplinary Community Resilience Modeling To Reduce Disaster Risk: Building Back Better, Wanting "Lisa" Wang, John W. Van De Lindt, Blythe Johnston, P. Shane Crawford, Guirong Grace Yan, Thang Dao, Trung Do, Katie Skakel, Mojtaba Harati, Tu Nguyen, Robinson Umeike, Silvana Croope, Andre R. Barbosa

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

From december 10 to december 11, 2021, a deadly tornado outbreak struck across several states in the us, including arkansas, illinois, kentucky, and tennessee. This tornado outbreak resulted in at least $3.9 Billion in damage, more than 90 fatalities, and hundreds of injuries. Mayfield, kentucky, a small city in the eastern united states, was hit by a long-track tornado rated as an enhanced fujita 4 (ef4) scale and was one of the communities most heavily damaged during the tornado outbreak. Following the 2021 tornado event, an analysis was performed in the interdependent networked community resilience modeling environment (in-core) for the …