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Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
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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
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 …
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
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 …
Chloride Binding Mechanism In Seawater-Mixed Uhpc, Wei Zhang, Dawei Ding, Mengmeng Li, Tiao Wang, Hongyan Ma, Binmeng Chen, Hongxing Hu, Jizhou Chen, Xiaomin Liu, Dongshuai Hou
Chloride Binding Mechanism In Seawater-Mixed Uhpc, Wei Zhang, Dawei Ding, Mengmeng Li, Tiao Wang, Hongyan Ma, Binmeng Chen, Hongxing Hu, Jizhou Chen, Xiaomin Liu, Dongshuai Hou
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The rapid development of marine concrete structures and the sharp shortage of freshwater resources contribute to the wide investigation of seawater-mixed ultra-high-performance concrete (swuhpc). However, few studies have investigated the chloride ions (cl-) binding mechanism of swuhpc. Herein, the chloride binding experiments and molecular dynamics (md) simulation were carried out to reveal the physically and chemically bound cl- mechanisms of swuhpc. The results of the experiments clearly demonstrate that the addition of silica fume (sf) led to a significant decrease in the capacity of cl- binding. Conversely, the incorporation of metakaolin (mk) resulted in a marked increase in the content …
A Review Of Whipple Shield Ballistic Limit Equations, S. Ryan, W. (William) P. Schonberg
A Review Of Whipple Shield Ballistic Limit Equations, S. Ryan, W. (William) P. Schonberg
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Ballistic limit equations (BLEs) are semi-analytical expressions used to predict the risk posed by micrometeoroid and orbital debris (MMOD) impacts on a spacecraft. A foundational BLE, known as the new non-optimum (NNO) equation was published by Eric Christiansen of NASA Johnson Space Center in 1990 for application on Whipple shields – two-plate configurations consisting of a thin sacrificial plate located at some standoff in front of the spacecraft pressure hull or structural wall. Today, BLEs for almost all multi-plate spacecraft structures, e.g., honeycomb sandwich panels, monolithic structures with thermal insulation blankets, etc., are based on the NNO Whipple BLE. We …
Four-Way Cfd-Dem Coupling To Simulate Concrete Pipe Flow: Mechanism Of Formation Of Lubrication Layer, Tooran Tavangar, Masoud Hosseinpoor, Jeffrey S. Marshall, Ammar Yahia, Kamal H. Khayat
Four-Way Cfd-Dem Coupling To Simulate Concrete Pipe Flow: Mechanism Of Formation Of Lubrication Layer, Tooran Tavangar, Masoud Hosseinpoor, Jeffrey S. Marshall, Ammar Yahia, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study introduced a four-way CFD-DEM coupling approach to simulate the shear-induced particle migration (SIPM) mechanism leading to formation of the lubrication layer (LL) during concrete pumping. The CFD-DEM simulations considered the coupled effect of concentration (10 %–40 %) and wide size distribution (1–17 mm) of aggregate and rheology of the mortar for forces between the suspending matrix and the particles (and vice versa), as well as force transmission directly between particles (and the pipe wall). The formation of the LL was successfully simulated through a more realistic understanding the SIPM mechanism and rheological evaluation across the pipe with comparable …
Modeling Inflation Transmission Among Different Construction Materials, Mohamad Abdul Nabi, Islam H. El-Adaway, Rayan H. Assaad
Modeling Inflation Transmission Among Different Construction Materials, Mohamad Abdul Nabi, Islam H. El-Adaway, Rayan H. Assaad
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Cost estimating in the construction industry is challenging due to the high uncertainty associated with the supply chain, especially after the COVID-19 pandemic. Some research studies have addressed such problems by developing models that predict material cost. In fact, all material can be interconnected and interrelated with lead-lag relationships such that any inflation in one material's price can be associated with inflation in other materials' prices, referred to as transmission of inflation. Despite the latter, none of the existing studies have investigated inflation transmission among all construction materials. This paper fills this knowledge gap. The authors used a multistep research …
Investigating Causes Of Disputes Resulting In Litigation In Airport Development Projects In The United States Using Graph-Based Techniques, Ramy Khalef, Islam H. El-Adaway
Investigating Causes Of Disputes Resulting In Litigation In Airport Development Projects In The United States Using Graph-Based Techniques, Ramy Khalef, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Airports represent a crucial a sector of the US infrastructure, but they were documented to have scored a D+. To mitigate this, governmental authorities have issued initiatives to update the airport infrastructure. With an expected critical junction for a major transformation in the airport sector, it is anticipated that airport projects will increase. This shall result in an escalation in the number of disputes. Previous research analyzed dispute concerns within the construction sector, but none tackled the perspective of airport projects. Accordingly, the goal of this study is to investigate the leading causes of disputes in litigation within US airport …
Ensemble-Learning Model Based Ultimate Moment Prediction Of Reinforced Concrete Members Strengthened By Uhpc, Woubishet Zewdu Taffese, Yanping Zhu, Genda Chen
Ensemble-Learning Model Based Ultimate Moment Prediction Of Reinforced Concrete Members Strengthened By Uhpc, Woubishet Zewdu Taffese, Yanping Zhu, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Data-driven model development brings new approaches to solve conventional civil engineering problems, which are usually considered and answered by experimental, analytical, and numerical methods. This study aims to develop an ensemble learning model (i.e., XGBoost: eXtreme Gradient Boosting) to predict ultimate moment of reinforced concrete (RC) members strengthened by a newly developed concrete technology – ultrahigh performance concrete (UHPC). The study considered two scenarios, incorporating eighteen and seventeen features, with one feature modification involving the transformation of width and height to the cross-sectional area of RC members. Incorporating three substrate damage levels, two substrate surface treatments preceding UHPC strengthening, and …
Risk–Reward Share Allocation Under Different Integrated Project Delivery Relational Structures: A Monte-Carlo Simulation And Cooperative Game Theoretic Solutions Approach, Radwa Eissa, Mohamad Abdul Nabi, Islam H. El-Adaway
Risk–Reward Share Allocation Under Different Integrated Project Delivery Relational Structures: A Monte-Carlo Simulation And Cooperative Game Theoretic Solutions Approach, Radwa Eissa, Mohamad Abdul Nabi, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Sharing of risks and rewards is considered to be one of the key benefits and principles of integrated project delivery (IPD). Despite its importance, risk–reward strategies are not implemented widely in IPD construction projects due to the lack of a well-defined basis for establishing adequate allocation plans. This paper fills this knowledge gap. This research followed a multistep methodology. First, the authors calculated the risk control valuations of all potential combinations of coalitions for IPD stakeholders. This was performed using interrelated steps of risk identification and quantification, risk assignment based on associated contractual analysis, establishment of a coordination network, and …
Comprehensive Understanding Of Factors Impacting Competitive Construction Bidding, Muaz O. Ahmed, Islam H. El-Adaway, Aubrie Caldwell
Comprehensive Understanding Of Factors Impacting Competitive Construction Bidding, Muaz O. Ahmed, Islam H. El-Adaway, Aubrie Caldwell
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Construction competitive bidding has been studied by many researchers; however, their focus was mainly on certain bidding aspects. Thus, despite their value, existing bidding models have limited applicability for various reasons including the non-inclusion of some real-life factors that impact bidding-related decisions. As such, there is a need for identifying a comprehensive list of bidding factors that impact construction bidding-related decisions, studying their associations, and identifying understudied factors to direct future research efforts. This paper fills this knowledge gap. First, the authors conducted a systematic selection of 124 construction bidding-related articles published within the past 40 years. Second, the authors …
Effects Of Rest Time And Curing Regime On Short- And Long-Term Strength Of Class C Fly Ash-Based Alkali-Activated Mortars, Cedric Kashosi, Ahmed Gheni, Eslam Gomaa, Mohamed Elgawady
Effects Of Rest Time And Curing Regime On Short- And Long-Term Strength Of Class C Fly Ash-Based Alkali-Activated Mortars, Cedric Kashosi, Ahmed Gheni, Eslam Gomaa, Mohamed Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study investigated how different rest times affect the strength development of fly-ash-based alkali-activated mortar (aam) over a period of 90 days. Two types of fly ash with varying calcium oxide contents of 37 and 21% were used. The rest times ranged from 2 to 36 h, and three curing methods (ambient, oven, and steam) were tested. The results showed that the rest time significantly influenced the compressive strength of the aam. The optimal rest time was found to be between 12 and 30 h depending on the curing method and fly ash type. Beyond this range, there were only …
Modeling And Understanding Dispute Causation In The Us Public-Private Partnership Projects, Mohamad Abdul Nabi, Rayan H. Assaad, Islam H. El-Adaway
Modeling And Understanding Dispute Causation In The Us Public-Private Partnership Projects, Mohamad Abdul Nabi, Rayan H. Assaad, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The partnership between the public and private sectors has led to a new and innovative way of delivering infrastructure projects that is referred to as public-private partnership (PPP). There are various benefits associated with PPP delivery methods including risk sharing, access to private funding, innovation, and flexibility, among others. Despite the proved benefits, contract conflicts and disputes are very common in PPP projects. While previous research studies examined the risks and the potential causes of conflicts in PPP projects, little-to-no research efforts were directed to study and model the interconnectivities between the different causes of conflicts in PPP agreements. To …
Comprehensive Numerical Modeling Of Prestressed Girder Bridges Under Low-Velocity Impact, Mohamed T. Elshazli, Mohanad M. Abdulazeez, Mohamed Elgawady, Ahmed Ibrahim
Comprehensive Numerical Modeling Of Prestressed Girder Bridges Under Low-Velocity Impact, Mohamed T. Elshazli, Mohanad M. Abdulazeez, Mohamed Elgawady, Ahmed Ibrahim
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Accidental Collisions Involving Over-Height Trucks That Exceed Vertical Clearance Limits And Bridge Superstructures Frequently Happen, Resulting In Compromised Girders And Potential Threats To Structural Safety And Performance. The Numerical Simulation Of Large-Scale Prestressed Girder Bridge Collisions Poses Challenges Due To The Associated Nonlinearities, As Well As The Limited Availability Of Large-Scale Experimental Testing Data In The Literature Due To Cost And Complexity Constraints. This Study Introduces A Numerical Modeling Approach To Efficiently Capture The Response Of Prestressed Girder Bridges Under Lateral Impact Loads. A Finite Element (FE) Model Was Developed Using LS-DYNA And Meticulously Validated Against Experimental Data From The …
Natural Gas Induced Vegetation Stress Identification And Discrimination From Hyperspectral Imaging For Pipeline Leakage Detection, Pengfei Ma, Ying Zhuo, Genda Chen, Joel G. Burken
Natural Gas Induced Vegetation Stress Identification And Discrimination From Hyperspectral Imaging For Pipeline Leakage Detection, Pengfei Ma, Ying Zhuo, Genda Chen, Joel G. Burken
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Remote Sensing Detection of Natural Gas Leaks Remains Challenging When using Ground Vegetation Stress to Detect Underground Pipeline Leaks. Other Natural Stressors May Co-Present and Complicate Gas Leak Detection. This Study Explores the Feasibility of Identifying and Distinguishing Gas-Induced Stress from Other Natural Stresses by Analyzing the Hyperspectral Reflectance of Vegetation. the Effectiveness of This Discrimination is Assessed Across Three Distinct Spectral Ranges (VNIR, SWIR, and Full Spectra). Greenhouse Experiments Subjected Three Plant Species to Controlled Environmental Stressors, Including Gas Leakage, Salinity Impact, Heavy-Metal Contamination, and Drought Exposure. Spectral Curves Obtained from the Experiments Underwent Preprocessing Techniques Such as Standard …
Circular Economy Policies For Decarbonization Of Us Commercial Building Stocks: Data Integration And System Dynamics Coflow Modeling Approach, Radwa Eissa, Islam H. El-Adaway
Circular Economy Policies For Decarbonization Of Us Commercial Building Stocks: Data Integration And System Dynamics Coflow Modeling Approach, Radwa Eissa, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Despite the recognition of the built environment as a sector with high potential for reducing embodied emissions, there is a lack of national-level data on embodied carbon emissions attributed to the US commercial building stocks. Hence, there is a need to benchmark the current state of embodied emissions attributed to the commercial built environment and the impact of circular economy (CE) policies for their decarbonization to facilitate well-informed decision-making. This paper fills this knowledge gap through providing policy makers with a framework that estimates the current and future projections of embodied carbon emissions attributable to the US commercial building stocks …
Methodology To Design Eco-Friendly Fiber-Reinforced Concrete For 3d Printing, Haodao Li, Alfred Addai-Nimoh, Eric Kreiger, Kamal H. Khayat
Methodology To Design Eco-Friendly Fiber-Reinforced Concrete For 3d Printing, Haodao Li, Alfred Addai-Nimoh, Eric Kreiger, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Greater use of locally available supplementary cementitious materials (SCM) to reduce cement content and addition of fiber reinforcement can enhance the performance of 3D printing (3DP) technology in construction. In this study, three classes of eco-friendly 3D printable fiber-reinforced mixtures were targeted, namely ultra-high-performance concrete (UHPC), high-performance concrete (HPC), and conventional concrete (CC). A step-by-step methodology was proposed to maximize the substitution rate of cement with SCM and limestone filler and optimize fiber volume for the successful development of 3D printable fiber-reinforced materials. Binder combinations were initially investigated on the paste level to determine the packing density and robustness. Selected …
Distributed Solar Generation: Current Knowledge And Future Trends, Gasser G. Ali, Islam H. El-Adaway
Distributed Solar Generation: Current Knowledge And Future Trends, Gasser G. Ali, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Distributed solar generation (DSG) has been growing over the previous years because of its numerous advantages of being sustainable, flexible, reliable, and increasingly affordable. DSG is a broad and multidisciplinary research field because it relates to various fields in engineering, social sciences, economics, public policy, and others. Developing a holistic understanding of the state of research related to DSG can be difficult. Motivated to provide that understanding, the goal of this paper is to explore current and emerging multidisciplinary research trends associated with DSG. To achieve that, (1) a large data set of approximately 66,000 publications was collected; (2) the …
Characterization Of Alkali-Silica Reaction (Asr) Products And C-S-H Using Swir Spectroscopy For Nondestructive Detection Of Asr, Pengfei Ma, Wenyu Liao, Ying Zhuo, Hongyan Ma, Yanping Zhu, Genda Chen
Characterization Of Alkali-Silica Reaction (Asr) Products And C-S-H Using Swir Spectroscopy For Nondestructive Detection Of Asr, Pengfei Ma, Wenyu Liao, Ying Zhuo, Hongyan Ma, Yanping Zhu, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study explores the feasibility of characterizing alkali-silica reaction (ASR) products and calcium silicate hydrates (C-S-H) from short-wave infrared (SWIR) spectroscopy. ASR products and C-S-H samples with different Ca/Si ratios were synthesized and analyzed through XRD, 29Si nuclei magnetic resonance (NMR) and SWIR spectroscopy. Fourier-transform infrared spectroscopy (FTIR) was collected to help interpret the results from the SWIR spectroscopy. The obtained spectroscopic features were applied to quantify the ASR product abundance denoted by the length expansion of mortar bars after an accelerated ASR test. The results show that the SWIR spectra of the synthetic ASR gels are similar regardless of …
Evolution Of Sbs-Modified Asphalt Performance Under Aging And Rejuvenation Cycle Conditions, Ke Shi, Feng Ma, Jenny Liu, Zhen Fu, Ruimeng Song, Dongdong Yuan, Aboudou Wassiou Ogbon
Evolution Of Sbs-Modified Asphalt Performance Under Aging And Rejuvenation Cycle Conditions, Ke Shi, Feng Ma, Jenny Liu, Zhen Fu, Ruimeng Song, Dongdong Yuan, Aboudou Wassiou Ogbon
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Improving the poor long-term service performance of rejuvenated SBS-modified asphalt (REF-LT) is highly challenging. In this study, a blend of aged and virgin binders was used to rejuvenate REF-LT and the evolution of the asphalt performance was observed during regeneration and reaging processes. An SBS-modified asphalt (SBM) and base asphalt (BA) were mixed with REF-LT in specified ratios to prepare SBM- and BA-rejuvenated asphalts. The rejuvenated asphalts were subjected to short- and long-term aging. The high/low-temperature rheological properties, fatigue resistance, rejuvenation mechanism, and changes in the functional groups of the rejuvenated and reaged asphalts were characterized using a dynamic shear …
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, Yasser Darwish, Mohamed A. Elgawady
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, Yasser Darwish, Mohamed A. Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Metamaterial structures that exhibit negative stiffness (MSNS) behavior have shown the potential to be used as energy dissipation systems in different applications. Negative stiffness honeycomb structures consist of multiple pre-buckled beams that snapping through from one pre-buckled mode to another buckled mode, when subjected to transverse loads, displaying negative stiffness, and dissipating a significant portion of the input energy. This paper presents finite element models (FEMs) developed to investigate the performance of negative stiffness pre-buckled beams and honeycombs. The FEMs were validated using experimental results of single pre-buckled beams and honeycomb structures. The experimental testing of the pre-buckled beams was …
Wearable Mxene-Graphene Sensing Of Influenza And Sars-Cov-2 Virus In Air And Breath: From Lab To Clinic, Yanxiao Li, Zhekun Peng, Jiaoli Li, Congjie Wei, Shangbin Liu, Weixing Hao, Huanyu Cheng, Casey Burton, Yang Wang, Yue-Wern Huang, Chang Soo Kim, Fang Yao Stephen Hou, Donghyun (Bill) Kim, Chenglin Wu
Wearable Mxene-Graphene Sensing Of Influenza And Sars-Cov-2 Virus In Air And Breath: From Lab To Clinic, Yanxiao Li, Zhekun Peng, Jiaoli Li, Congjie Wei, Shangbin Liu, Weixing Hao, Huanyu Cheng, Casey Burton, Yang Wang, Yue-Wern Huang, Chang Soo Kim, Fang Yao Stephen Hou, Donghyun (Bill) Kim, Chenglin Wu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The rapidly expanding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants demand a continuous monitoring method through portable and wearable devices. Utilizing the rich surface chemistry and high chemical-to-electrical signal conversion of 2D MXene-graphene heterostructure thin films, a field-effect-transistor (FET) sensor, which has a flexible substrate to be assembled onto the mask and combines with a Bluetooth system for wireless transmission is developed, to detect the influenza and SARS-CoV-2 viruses in air and breath. At first, the developed sensors are examined in the laboratory through direct contact with sensing targets in solution form. The results show a low …
Synergistic Effect Of Macro Synthetic Fiber And Shrinkage-Reducing Admixture On Engineering Properties Of Fiber-Reinforced Super-Workable Concrete, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat
Synergistic Effect Of Macro Synthetic Fiber And Shrinkage-Reducing Admixture On Engineering Properties Of Fiber-Reinforced Super-Workable Concrete, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study aims to enhance fiber-reinforced super-workable concrete (FR-SWC) by optimizing the system of shrinkage-reducing admixture (SRA) and macro-synthetic fiber (MSF) for low shrinkage and uncompromised mechanical properties. A factorial design approach was employed to model the effect of fiber content, SRA dosage, and combined ratios of two types of MSF on performance of FR-SWC. MSF content had the greatest impact on mechanical properties, followed by SRA and MSF combination. Using MSF increased equivalent flexural strength ratio by 310% compared to the control mixture, regardless of MSF combination and SRA. SRA had the most significant effect on drying shrinkage, followed …
From Pumping To Deposition: A Comprehensive Review Of Test Methods For Characterizing Concrete Printability, Ali Fasihi, Nicolas A. (Ali) Libre
From Pumping To Deposition: A Comprehensive Review Of Test Methods For Characterizing Concrete Printability, Ali Fasihi, Nicolas A. (Ali) Libre
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
3D concrete printing (3DCP) technology has gained significant attention in the construction industry due to its potential to revolutionize the way buildings are designed and constructed. However, successful application of 3DCP requires robust standard test procedures to characterize the printability of concrete. Printability is a measure of workability for a printing material in the 3DCP process, which is characterized by pumpability, extrudability, and buildability. This paper presents a comprehensive review of the test methods that could be used for material characterization during various printing steps, including pumping, extrusion, and layer deposition. The underlying mechanisms relevant to each step, key governing …
Advancing Occupational Health In Mining: Investigating Low-Cost Sensors Suitability For Improved Coal Dust Exposure Monitoring, Mirza Muhammad Zaid, Nana Amoah, Ashish Kakoria, Yang Wang, Guang Xu
Advancing Occupational Health In Mining: Investigating Low-Cost Sensors Suitability For Improved Coal Dust Exposure Monitoring, Mirza Muhammad Zaid, Nana Amoah, Ashish Kakoria, Yang Wang, Guang Xu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Exposure to coal dust in underground coal mines poses significant health risks to workers, including the development of diseases such as coal workers' pneumoconiosis and silicosis. Current available methods for monitoring coal dust exposure are expensive and time-consuming, necessitating the exploration of alternative approaches. Low-cost light scattering particulate matter sensors offer a promising solution, and its development in recent years has demonstrated some success in air quality monitoring However, its application in sensing coal particles is limited partially due to that the operating condition in a mine is different than the atmosphere. Thus, the objective of this paper is to …
Use Of Hybrid Fibers And Shrinkage Mitigating Materials In Scc For Repair Applications, Kamran Aghaee, Kamal H. Khayat
Use Of Hybrid Fibers And Shrinkage Mitigating Materials In Scc For Repair Applications, Kamran Aghaee, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Self-consolidating concrete (SCC) is used to repair structural elements with congested reinforcement or restricted access to placement and consolidation. In addition to adequate flowability, passing ability, filling capacity, and stability, adequate bonding to the substrate and reinforcing bars, low shrinkage and cracking resistance are required for successful repair. This study employs various shrinkage mitigating materials, including expansive agent (EA), coupled use of EA with shrinkage reducing admixture (SRA), and EA with pre-saturated lightweight sand (LWS) to fulfill these requirements. The effect of these materials on the performance of SCC made with a hybrid synthetic (PP) fiber and a hybrid steel-synthetic …
Data-Driven Analysis Of Progressive Design Build In Water And Wastewater Infrastructure Projects, Fareed Salih, Radwa Eissa, Islam H. El-Adaway
Data-Driven Analysis Of Progressive Design Build In Water And Wastewater Infrastructure Projects, Fareed Salih, Radwa Eissa, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The United States has invested heavily in water and wastewater infrastructure projects to address growing demand and aging systems. To ensure the effective delivery of these projects, agencies are shifting toward alternative delivery methods such as progressive design build (PDB), which has demonstrated accelerated schedule and enhanced cost performance across the literature as well as multiple projects compared to traditional DB. This has raised a need for evaluating PDB's state of adoption and performance in the water and wastewater sector. To this end, the authors: (1) conducted descriptive and statistical analyses of the 21 PDB water and wastewater projects available …
Performance Of Smart Shear Keys In Concrete Bridges Under Tsunami Loading: An Experimental Study, Haibin Zhang, Xinzhe Yuan, Genda Chen, Pedro Lomonaco
Performance Of Smart Shear Keys In Concrete Bridges Under Tsunami Loading: An Experimental Study, Haibin Zhang, Xinzhe Yuan, Genda Chen, Pedro Lomonaco
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Bridges have recently been exposed to an increasing number of natural hazards such as earthquakes and tsunamis. These extreme events have resulted in transverse offsets, overturning moments, and even dropping-off of superstructures due to their weak connection to substructures. These outcomes are potentially prevented or mitigated by developing and deploying sliding, modular, adaptive, replaceable, and two-dimensional (SMART) shear keys as fuse elements between superstructures and substructures. The novelty of SMART shear keys is to enable an adaptive control of both the force and displacement of bridges under different types of loads. In this study, the performance of SMART shear keys …
An Accurate-Pricing Estimate Game-Theoretic Model For Determining Price Escalations In Construction Projects During Economic Uncertainties, Yasser Jezzini, Rayan H. Assaad, Islam H. El-Adaway, Mohamad Abdul Nabi
An Accurate-Pricing Estimate Game-Theoretic Model For Determining Price Escalations In Construction Projects During Economic Uncertainties, Yasser Jezzini, Rayan H. Assaad, Islam H. El-Adaway, Mohamad Abdul Nabi
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Economic Market Uncertainties, Such As Those Experienced During The COVID-19 Pandemic, Can Make Determining Accurate Prices Estimate For Construction Materials A Challenging Task. While Previous Research Focused On The Contractual Aspect Of This Issue By Studying Price Escalation Clauses, There Is Still A Gap In The Literature When It Comes To Proposing An Accurate Pricing Model. Thus, This Study Develops An Accurate Pricing-Estimate Game-Theoretical Model That Can Efficiently And Competitively Account For Escalations In Construction Materials Prices During Uncertain Market Conditions. First, Data On Past Producer Price Indexes (PPIs) Of Different Construction Materials Were Collected. Second, The Percentage Changes In …
Predicting Construction Costs Under Uncertain Market Conditions: Probabilistic Forecasting Using Autoregressive Recurrent Networks Based On Deepar, Ghiwa Assaf, Rayan H. Assaad, Islam H. El-Adaway, Mohamad Abdul Nabi
Predicting Construction Costs Under Uncertain Market Conditions: Probabilistic Forecasting Using Autoregressive Recurrent Networks Based On Deepar, Ghiwa Assaf, Rayan H. Assaad, Islam H. El-Adaway, Mohamad Abdul Nabi
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Projects Often Experience Cost Overruns Due To Market Uncertainty And Price Escalations. Traditional Cost Estimation Methods That Rely On Point Estimation Are Incapable Of Providing Prediction Intervals As Well As Probabilistic Assessment. Thus, There Is Need For An Innovative Approach To Predict The Changes And Uncertainties In Construction Material Costs. This Paper Proposes A Novel Stochastic Model To Estimate Construction Material Costs By Applying Probabilistic Forecasting Using Autoregressive Recurrent Networks. First, Price Data Was Collected For Four Different Construction Materials. Second, Data Was Divided Into A Training Set (Pre-COVID-19) And A Testing Test (Post-COVID-19). Third, The State-Of-The-Art DeepAR Algorithm Was …
Assessing The Impact Of Skilled Labor Shortages On Project Cost Performance, Tamima S. Elbashbishy, Islam H. El-Adaway
Assessing The Impact Of Skilled Labor Shortages On Project Cost Performance, Tamima S. Elbashbishy, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Over The Past Decade, There Has Been A Notable Increase In Skilled Labor Shortages Within The Construction Industry. This Shortage Has Numerous Negative Consequences On Construction Projects, Such As Delays In Completion, Compromised Quality, And Higher Costs. Therefore, The Goal Of This Paper Is To Examine The Extent Of Skilled Labor Shortages Observed Throughout The Industry And Their Impact On The Cost Performance Of Construction Projects. To Achieve This Goal, The Authors Identified 10 Key Construction Trades That Heavily Rely On Skilled Labor. Subsequently, An Industry Survey Was Conducted To Measure The Extent Of Skilled Labor Shortages, As Well As …