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Articles 121 - 150 of 7868
Full-Text Articles in Civil and Environmental Engineering
Data-Driven Shear Capacity Prediction Of Studs Embedded In Uhpc For Steel-Uhpc Composite Structures, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen
Data-Driven Shear Capacity Prediction Of Studs Embedded In Uhpc For Steel-Uhpc Composite Structures, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study employs ensemble learning algorithms to accurately predict the shear capacity of studs embedded in ultrahigh performance concrete (UHPC), a critical aspect of structural engineering. Using a comprehensive data set featuring six UHPC slab features, seven stud features, and one shear pocket feature, 35 ensemble models are developed across five cases and seven algorithms (bagging, random forest, AdaBoost, gradient boosting, XGBoost, CatBoost, and LightGBM). The Shapley additive explanations (SHAP) analysis is conducted on the top-performing models to gain insights into their decision-making mechanisms. Results indicate that transforming UHPC slab geometry parameters into a volume, alongside different diameter ratios, proves …
Temporal Evolution Of Workforce Fatality-Linked Factors In The Transportation Construction Sector, Mariam Elazhary, Islam H. El-Adaway
Temporal Evolution Of Workforce Fatality-Linked Factors In The Transportation Construction Sector, Mariam Elazhary, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Despite advancements in safety measures, fatalities in the transportation sector remain disproportionately higher than in other industries. Transportation sector fatalities arise from a combination of demographic, environmental, and occupational factors that amplify the overall risk. While strides have been made in understanding the factors contributing to fatalities, there remains a critical gap in research focused on their temporal evolution. The goal of this study is to investigate the temporal evolution of fatality-linked association factors in the transportation construction sector. The methodology encompassed three stages. Stage 1 was preprocessing the data: the US Census of Fatal Occupational Injuries, covering 3,792 fatality …
Labor Productivity Losses Across Construction Trades: A Machine Learning Approach, Tamima Elbashbishy, Islam H. El-Adaway
Labor Productivity Losses Across Construction Trades: A Machine Learning Approach, Tamima Elbashbishy, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Labor productivity is a major concern in the construction industry. Existing research on construction labor productivity (CLP) within specific trades has produced inconsistent findings due to differences in the factors analyzed. This lack of consistency makes it difficult to identify the most critical drivers of productivity losses across trades. To address this gap, this study adopts a cross-trade analytical approach to systematically identify and evaluate the inefficiencies impacting labor productivity in multiple construction trades. Specifically, the study (1) identified common organizational and project-level inefficiencies that influence labor performance; (2) conducted an expert-based survey to measure the frequency and perceived impact …
Failure Analysis Of Prestressed Concrete Girder Bridges Under Over-Height Truck Impacts, Mohamed T. Elshazli, Mohamed Elgawady, Tao Xing, Ahmed Ibrahim
Failure Analysis Of Prestressed Concrete Girder Bridges Under Over-Height Truck Impacts, Mohamed T. Elshazli, Mohamed Elgawady, Tao Xing, Ahmed Ibrahim
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Accidental collisions between over-height trucks and bridge superstructures are a common threat to existing bridge infrastructure. These incidents often stem from illegal over-height vehicles or truck operators' unawareness of clearance limits, posing serious safety risks and causing substantial structural damage. This study presents a comprehensive numerical investigation of the dynamic response of prestressed concrete girder bridges subjected to over-height truck impacts. Large-scale finite element models were developed in LS-DYNA, with validation conducted against experimental results. The parametric study explored impact speeds ranging from 16 to 113 km/h (10 to 70 mph), impactor masses between 2 and 6 tons, impact locations, …
Enabling Carbon Dioxide Mineralization And Active Set Control In Portlandite-Based Cementitious Suspensions, Xiaodi Dai, Sharu Bhagavathi Kandy, Rui Xiao, Manas Sarkar, Shubham Wani, Thiyagarajan Ranganathan, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gädt, Samanvaya Srivastava, Gaurav Sant
Enabling Carbon Dioxide Mineralization And Active Set Control In Portlandite-Based Cementitious Suspensions, Xiaodi Dai, Sharu Bhagavathi Kandy, Rui Xiao, Manas Sarkar, Shubham Wani, Thiyagarajan Ranganathan, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gädt, Samanvaya Srivastava, Gaurav Sant
Materials Science and Engineering Faculty Research & Creative Works
The real-time control of concrete's stiffening allows users to better control pumping and extrusion during 3D-printing processes. Here, a portlandite-based cementitious formulation (i.e., slurry or suspension) that features the potential for rapid CO2 uptake is adapted for 3D-printing applications. In particular, we showcase a portlandite-fly ash binder system combined with a thermo responsive polymer, wherein precise control via thermal activation allows set control and rapid solidification. Through the thermally induced polymerization of polyacrylamide, the hybrid binder system rapidly undergoes stiffening at trigger onset temperatures ranging from 60 °C to 80 °C, exhibiting average stiffening rates of up to 2600 …
Exploring The Adoption Of Construction Technologies In Infrastructure Projects: Bridging Perceptions Of Experts With Real Project Data, Fareed Salih, Islam H. El-Adaway
Exploring The Adoption Of Construction Technologies In Infrastructure Projects: Bridging Perceptions Of Experts With Real Project Data, Fareed Salih, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Infrastructure projects have progressively adopted construction technologies, yet previous studies have not fully explored technology utilization by comparing the perceptions of experts with actual project data. This research fills this knowledge gap. The authors (1) developed, distributed, and collected a survey completed by 52 construction practitioners to investigate the use of these technologies and their associated benefits; (2) checked the survey reliability and validity using Cronbach's alpha test; (3) investigated the perceptions of utilizing construction technologies across industry sectors; (4) explored the perceptions of benefits across industry sectors; (5) analyzed the impact of construction technologies on project objectives and phases …
Guiding State-Specific Studies On Highway Disasters: Examining Differences In Postdisaster Funding, Mariam Elazhary, Islam H. El-Adaway
Guiding State-Specific Studies On Highway Disasters: Examining Differences In Postdisaster Funding, Mariam Elazhary, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The highway sector is frequently and severely impacted by natural disasters. To mitigate these effects and reduce the need for large relief budgets or emergency funds, it is crucial to study the resilience of the transportation network. As such, defining resilience in absolute terms is not enough; instead, it is equally important to analyze specific case studies and build a lessons-learned rapport. This is critical because it helps identify unique vulnerabilities and strengths that might be overlooked in broader analyses. However, current research on highway resilience often lacks empirical evidence to support the selection of these unique and significant case …
Detection Of Bacterial Genomic Dna Fragments Using The Mxene Crispr-Cas9 Field-Effect Transistor, Jiaoli Li, Ali Taheri, Weijia Liu, Ying Zhuo, Pengfei Ma, Chenglin Wu
Detection Of Bacterial Genomic Dna Fragments Using The Mxene Crispr-Cas9 Field-Effect Transistor, Jiaoli Li, Ali Taheri, Weijia Liu, Ying Zhuo, Pengfei Ma, Chenglin Wu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Clustered regularly interspaced short palindromic repeats (CRISPR)-based field-effect transistor (FET) sensors provide a promising platform for highly specific and amplification-free nucleic acid detection. However, their direct application in identifying target sequences within intact genomic DNA remains underexplored. We developed a CRISPR-Cas9 FET sensor for detecting DNA sequences by immobilizing Cas9 onto a graphene-MXene sensing interface via (3-aminopropyl)triethoxysilane (APTES) functionalization. The sensor targeted Stx1, a 440 bp laboratory-amplified fragment associated with Shiga toxin production in pathogenic E. coli. Gel electrophoresis confirmed the precise cleavage of Stx1, while the nontarget sequence Stx2 remained undetected. FET measurements further validated the sensor's specificity, showing …
Demystifying The Discharge Coefficient For Flow Over Thin Weirs And Sills, Joseph E. Pugh, Subhas Karan Venayagamoorthy, Timothy K. Gates
Demystifying The Discharge Coefficient For Flow Over Thin Weirs And Sills, Joseph E. Pugh, Subhas Karan Venayagamoorthy, Timothy K. Gates
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
A revised derivation of the discharge coefficient for flows over thin weirs and sills in the limits of wall overflow to a free overfall is given. Using dimensional analysis, we show that the discharge coefficient, (Formula presented), in the classical weir-discharge equation is best understood as a weir Froude number, (Formula presented), which accounts for the combined effects of inertia, contraction and viscous energy losses within the flow field. A comprehensive set of experimental data from historical studies is complimented by new data from the authors, featuring both laboratory flume experiments and three-dimensional numerical simulations of weir flows. Synthesis of …
Stabilization Of Cr³⁺ Using Iron Rich Slag-Derived Phosphate Cement: An Integrated Solution For Heavy Metals And Hazardous Solid Wastes, Ting Huang, Hongyan Ma, Zhongqiu Luo, Xintao Zhou, Zhengqing He, Peiwen Lv, Xiunan Cai, Pingyan Wang
Stabilization Of Cr³⁺ Using Iron Rich Slag-Derived Phosphate Cement: An Integrated Solution For Heavy Metals And Hazardous Solid Wastes, Ting Huang, Hongyan Ma, Zhongqiu Luo, Xintao Zhou, Zhengqing He, Peiwen Lv, Xiunan Cai, Pingyan Wang
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
A novel iron-based phosphate cement (IPC), derived from iron-rich smelting slag (ISS), was developed as a sustainable and efficient binder for the stabilization/solidification of trivalent chromium (Cr3+). The mechanical properties, hydration behavior, microstructure, leaching toxicity, chromium chemical forms, and environmental safety of chromium-stabilized iron phosphate cement (CIPC) were thoroughly evaluated. The results showed that, with a mass ratio of ISS to ammonium dihydrogen phosphate (ADP) of 2.0, and even with the addition of 20 % chromium nitrate nonahydrate (CN), the compressive strength of CIPC reached 4.2 MPa after curing for 28 d. Furthermore, chromium leaching was well below …
Influence Of Mixing Duration And Absorption Characteristics Of Superabsorbent Polymers On The Fresh And Hardened Properties Of High-Performance Concrete, Yu Cun Gu, Kamal H. Khayat
Influence Of Mixing Duration And Absorption Characteristics Of Superabsorbent Polymers On The Fresh And Hardened Properties Of High-Performance Concrete, Yu Cun Gu, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study investigates the combined influence of superabsorbent polymers (SAPs) with distinct absorption kinetics and extended mixing sequences on the rheological, mechanical, and transport properties of high-performance concrete (HPC). Two SAPs—an ionic acrylamide-co-acrylic acid copolymer (SAP-P) and a non-ionic acrylamide polymer (SAP-B)—were incorporated at an internal curing level of 100%. The impact of extended mixing times (3, 5, and 7 min) following SAP addition was systematically evaluated. Results showed that longer mixing durations led to increased superplasticizer demand and higher plastic viscosity due to continued water absorption by SAPs. However, yield stress remained relatively stable owing to the dispersing effect …
Localized Multivariate Statistical Assessment Of United States Construction Labor Shortages, Ahmed Shiha, Islam H. El-Adaway
Localized Multivariate Statistical Assessment Of United States Construction Labor Shortages, Ahmed Shiha, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Craft labor shortage is a persistent challenge facing the construction industry across various markets. The historically low geographic mobility of construction labor exacerbates and localizes labor shortages. Several research efforts relied on subjective evaluations to quantify the existence of labor shortages on a national level. As such, there is a lack of empirical quantification of labor shortages at different geospatial levels. This paper fills this knowledge gap. To this end, the authors adopted a methodology that encompassed: (1) conducting a literature review to identify and collect national-level and subnational indicators that explain the changes in labor supply and demand; (2) …
Coupling Effect Of Abrasion And Erosion On Ultrahigh-Performance Seawater-Sea Sand Concrete, Dawei Ding, Wei Zhang, Lanqin Wang, Hongyan Ma, Biqin Dong, Song Han, Hongjian Xu, Dongshuai Hou
Coupling Effect Of Abrasion And Erosion On Ultrahigh-Performance Seawater-Sea Sand Concrete, Dawei Ding, Wei Zhang, Lanqin Wang, Hongyan Ma, Biqin Dong, Song Han, Hongjian Xu, Dongshuai Hou
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Preparing ultrahigh-performance seawater-sea sand concrete (UHPSSC) to mitigate the scarcity of freshwater and river sand resources has generated considerable recent research interest. However, the deterioration mechanisms of UHPSSC under the effect of abrasion and erosion remain unstudied. In this paper, the underwater steel ball method was conducted to evaluate the impact of seawater, sea sand, steel fiber, and seawater abrasion on the abrasion resistance of UHPSSC. Then the stress erosion models of calcium-silicate-hydrate (C-S-H) were constructed to investigate the degradation mechanisms of UHPSSC under the effect of external stress and seawater erosion. The results show that the application of seawater …
Visceral, Neural, And Immunotoxicity Of Per- And Polyfluoroalkyl Substances: A Mini Review, Pietro Martano, Samira Mahdi, Tong Zhou, Yasmin Barazandegan, Rebecca Iha, Hannah Do, Joel Burken, Paul Ki-Souk Nam, Qingbo Yang, Ruipu Mu
Visceral, Neural, And Immunotoxicity Of Per- And Polyfluoroalkyl Substances: A Mini Review, Pietro Martano, Samira Mahdi, Tong Zhou, Yasmin Barazandegan, Rebecca Iha, Hannah Do, Joel Burken, Paul Ki-Souk Nam, Qingbo Yang, Ruipu Mu
Chemistry Faculty Research & Creative Works
Per- and polyfluoroalkyl substances (PFASs) have gained significant attention due to their widespread distribution in the environment and potential adverse health effects. While ingestion, especially through contaminated drinking water, is considered the primary route of human exposure, recent research suggests that other pathways, such as inhalation and dermal absorption, also play a significant role. This review provides a concise overview of the toxicological impacts of both legacy and emerging PFASs, such as GenX and perfluoro butane sulfonic acid (PFBS), with a particular focus on their effects on the liver, kidneys, and immune and nervous systems, based on findings from recent …
Utilization Of Ftir-Atr For Material Characterization And Forensic Analysis, Helmut Leodarta, Ahmed S. El-Ashwah, Punyaslok Rath, Magdy Abdelrahman, William G. Buttlar
Utilization Of Ftir-Atr For Material Characterization And Forensic Analysis, Helmut Leodarta, Ahmed S. El-Ashwah, Punyaslok Rath, Magdy Abdelrahman, William G. Buttlar
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The growing use of chemical modifiers and additives in asphalt mixtures necessitates a reliable system for their identification and quantification, crucial for quality control, assurance, and forensic investigations. Fourier Transform Infrared (FTIR) spectroscopy offers a cost-effective method by analyzing the interaction of infrared light with chemical groups, producing distinct spectral fingerprints. This study evaluates 44 materials, including binders, warm mix additives (WMAs), rejuvenators, release agents, and concrete admixtures. It also assesses the ability of FTIR testing to identify and quantify chemical changes and aging in asphalt binders with rejuvenator addition. An Attenuated Total Reflectance (ATR) accessory was employed for practical …
Mechanical And Deformation Behavior Of Silt Reinforced With Wicking Geotextile: An Experimental Study, Yipeng Guo, Yiyong Xue, Yongjie Zhang, Wei Ruan, Yafeng Li, Xiong Zhang, Zhili Han
Mechanical And Deformation Behavior Of Silt Reinforced With Wicking Geotextile: An Experimental Study, Yipeng Guo, Yiyong Xue, Yongjie Zhang, Wei Ruan, Yafeng Li, Xiong Zhang, Zhili Han
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Silt is widely utilized as a filling material in transportation construction, However, it frequently suffers from problems, such as excess pore water pressure buildup, settlement, and mud pumping. Wicking geotextiles have emerged as a sustainable solution by improving both drainage and reinforcement capacities, yet their optimal design parameters remain unclear. To address this gap, a series of tests were performed to investigate the effects of compaction degree, reinforcement configuration (number, spacing, position), and specimen geometry on the mechanical and consolidation of silt reinforced with wicking geotextiles. The results reveal that the failure mechanism of reinforced silt progresses through four distinct …
Modeling Framework To Quantify And Gauge Project Cost Risks Due To Construction Material Price Volatilities Using Predictive Probabilistic Deep-Learning Algorithms And Stochastic Risk Modeling, Yasser Jezzini, Rayan H. Assaad, Islam H. El-Adaway
Modeling Framework To Quantify And Gauge Project Cost Risks Due To Construction Material Price Volatilities Using Predictive Probabilistic Deep-Learning Algorithms And Stochastic Risk Modeling, Yasser Jezzini, Rayan H. Assaad, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Material price fluctuations pose significant challenges for executing construction projects and adhering to budgetary estimates. Existing research studies focused on forecasting construction material prices rather than quantifying and gauging overall project cost risks related to price volatilities, and they relied on traditional time-series forecasting methods that are incapable of offering full probabilistic distributions of price fluctuations and of providing a comprehensive assessment of risk uncertainties associated with material price fluctuations. This paper addresses these gaps by developing an integrated framework to quantify and gauge project risks due to construction material price volatilities. The framework's validity and practicality were demonstrated using …
Ftir Characterization Of Asphalt Sara Fractions In Response To Rubber Modification, Mohyeldin Ragab, Eslam Deef-Allah, Magdy Abdelrahman
Ftir Characterization Of Asphalt Sara Fractions In Response To Rubber Modification, Mohyeldin Ragab, Eslam Deef-Allah, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Asphalt–rubber binders (A-RBs) have a long and deep history of use; however, little is known regarding the interrelated chemical behaviors and miscibility of rubber with the asphalt fractions [saturates, aromatics, resins, and asphaltenes (SARA)]. This study comprehensively attempted to address this knowledge deficiency by employing Fourier transform infrared spectroscopy (FTIR) to investigate the chemical evolution of A-RBs. A-RB interacted at 190 °C and 3000 min−1 for 8 h was deemed to have the optimal rheological performance. FTIR of the liquid fractions of A-RB 190–3000 showed a prominent chemical shift in the SARA fractions, with new peaks that showed rubber …
Characterization Of The Effects Of Waste Mullite Powder On Seawater Sea Sand Cementitious Materials, Xiao Sun, Zehui Zhou, Wenjie He, Yudong Bi, Yao Wang, Hengrui Liu, Rui Zhong, Hongyan Ma
Characterization Of The Effects Of Waste Mullite Powder On Seawater Sea Sand Cementitious Materials, Xiao Sun, Zehui Zhou, Wenjie He, Yudong Bi, Yao Wang, Hengrui Liu, Rui Zhong, Hongyan Ma
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Maintaining the durability of coastal concrete structures while reducing construction costs remains a formidable challenge. Drawing inspiration from the volcanic concrete used by ancient Greeks and Romans, this study explores the feasibility of using waste mullite powder (WMP) with a high alumina content in seawater sea sand concrete to conserve natural resources and enhance durability. The experimental results demonstrate that the incorporation of seawater and WMP exerts detrimental impacts on the flow characteristics and workability of cementitious composites. While the sulfate content in seawater and sea sand can bolster the early strength of sea sand seawater concrete, sulfate attack compromises …
Geopolymer Clsm With Off-Specification Fly Ash And Bottom Ash: A Sustainable Approach To Hazardous Waste Utilization, Alexis K. Vandomelen, Ahmed A. Gheni, Eslam Gomaa, Mohamed A. Elgawady
Geopolymer Clsm With Off-Specification Fly Ash And Bottom Ash: A Sustainable Approach To Hazardous Waste Utilization, Alexis K. Vandomelen, Ahmed A. Gheni, Eslam Gomaa, Mohamed A. Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Conventional controlled low-strength material (CLSM) is a self-consolidating cementitious material with high flowability and low strength, traditionally composed of cement, sand, and water. This study explores the sustainable utilization of off-specification fly ash (OSFA) and bottom ash (BA), classified as industrial by-products with potential environmental hazards, to develop eco-friendly geopolymer CLSM as an alternative to conventional CLSM. Sodium hydroxide (NaOH) was used as an alkali activator to stabilize and solidify both two-part (liquid NaOH) and one-part (solid NaOH pellets) geopolymer CLSM mixtures. These mixtures were evaluated based on flowability (ASTM D6103-17) and compressive strength (< 300 psi per ACI Committee 229 guidelines for excavatability). A cost analysis was also conducted. The results demonstrated that incorporating OSFA as a cement replacement increased water demand by 15% to meet flowability requirements, while BA substitution for sand led to segregation challenges requiring mixture adjustments. For two-part mixtures, higher carbon content in OSFA necessitated an increased water-to-fly ash ratio. All self-consolidating mixtures exhibited 1-day compressive strengths ranging from 5 psi (0.03 MPa) to 87 psi (0.6 MPa). One-part mixtures showed a 1% to 34% reduction in 7-day compressive strength compared to two-part mixtures, improving excavatability. Increasing the BA-to-OSFA ratio from 1:1 to 3:1 reduced water demand due to lower surface area but increased the NaOH/OSFA ratio. This study highlights the potential of geopolymer CLSM to reduce costs by up to 94% at current NaOH prices (USD 6 per cubic yard) while repurposing hazardous industrial by-products, offering a cost-efficient, sustainable, and environmentally responsible solution for CLSM production.
Retraction: A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas(Seismological Research Letters (2022), 93, 5, (2731–2739), 10.1785/0220210310), Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li
Retraction: A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas(Seismological Research Letters (2022), 93, 5, (2731–2739), 10.1785/0220210310), Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
An earlier version of this article (Liu et al., 2022) included private data from the Himalayan-III program which should not have been made public. The authors acknowledge and regret their negligence during the selection of the measurements. The impacted data represent only 2.7% of the total data published in this article, and after review, the authors and the editors agree that this unintentional error has no bearing on the work's scientific conclusions. Therefore, we are retracting the impacted data and have made corrections to remove any Himalayan-III program data from the article's text, figures, and supplemental tables.
Investigating The Thixotropy Of Fresh Struvite Cement-Based Composite: Insights On Mechanisms Of The Pastes’ Thixotropic Behavior, Ugochukwu Ewuzie, Abdulkareem O. Yusuf, Damilola Daramola, Monday Uchenna Okoronkwo
Investigating The Thixotropy Of Fresh Struvite Cement-Based Composite: Insights On Mechanisms Of The Pastes’ Thixotropic Behavior, Ugochukwu Ewuzie, Abdulkareem O. Yusuf, Damilola Daramola, Monday Uchenna Okoronkwo
Chemical and Biochemical Engineering Faculty Research & Creative Works
Struvite (ST) recovered during wastewater treatment has been sparsely applied in cement-based composites. This study systematically evaluated the thixotropic behavior of cement-struvite (CST) pastes, a mix of 5–20 % ST by mass of cement, and proposed the interaction mechanisms leading to the pastes' thixotropy. The hysteresis loop area was used to establish the pastes' thixotropy and investigate its relationship with increased ST content, temperature, and yield stress. In the thixotropic behavior model used, the equilibrium shear stress was employed to examine the CST pastes' irreversible change; the characteristic time of deflocculation was used to study the flocs destruction process; and …
Data-Driven Prediction Of Binder Rheological Performance In Rap/Ras-Containing Asphalt Mixtures, Eslam Deef-Allah, Magdy Abdelrahman
Data-Driven Prediction Of Binder Rheological Performance In Rap/Ras-Containing Asphalt Mixtures, Eslam Deef-Allah, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Asphalt recycling technologies have advanced considerably over the last few decades with the utilization of reclaimed asphalt pavements (RAP) and recycled asphalt shingles (RAS). Characterizing aged and heterogeneous binders in these mixtures is challenging, particularly with limited extracted binders. This study suggests a data-driven framework that considers the rheological, chemical, and thermal characteristics to predict the binders' performance. Ninety-seven mixtures with 0–35% of the asphalt binder replaced with RAP/RAS binders were included as cores from the field, plant-produced mixtures, and laboratory-fabricated mixtures. The binders were chemically quantified using aging, aromatic, and aliphatic indices. Thermal analyses of the binders involved the …
Ultra-Low Dosages Of Novel Graphene Types Enhance The Rheological Properties And Buildability Of 3d Printed Binders, Sahil Surehali, Akshay Venkatachalam, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath
Ultra-Low Dosages Of Novel Graphene Types Enhance The Rheological Properties And Buildability Of 3d Printed Binders, Sahil Surehali, Akshay Venkatachalam, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath
Materials Science and Engineering Faculty Research & Creative Works
The use of graphene as a high-performance concrete additive is attractive; but, its cost and concerns about production scalability and dispersion efficiency in concrete are impediments to widespread use. This study explores the impact of ultra-low dosages (≤0.02 % by mass of binder) of two novel graphene types—fractal graphene (FG) and reactive graphene (RG)—produced through a cost-effective, environmentally friendly, and scalable process, on the rheological properties of 3D-printable concrete. Both FG and RG significantly enhance the dynamic and static yield stresses and viscoelastic properties of the binder, with RG-modified mixtures exhibiting slightly more pronounced enhancements due to the presence of …
Treatment And Activation Effects On Kaolinite-Based Earth Concrete, Mojtaba Kohandelnia, Maroua Zerzouri, Ammar Yahia, Kamal H. Khayat
Treatment And Activation Effects On Kaolinite-Based Earth Concrete, Mojtaba Kohandelnia, Maroua Zerzouri, Ammar Yahia, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Self-consolidating earth concrete (SCEC) addresses the long construction process of conventional earthen constructions and their structural limitations, while further efforts are needed to enhance its sustainability. This study explores the development of a kaolinite-based self-consolidating earth paste (SCEP) due to their blended powder system, incorporating raw and treated (calcined and ground-calcined) kaolinite under various activation techniques, such as water hydration, sodium hexametaphosphate (NaHMP), and sodium hydroxide (NaOH) activation. The synergistic effect of calcination and mechanosynthesis on rheological, mechanical, structural, and microstructural properties of SCEP were investigated. Mechanically treated kaolinite increased yield stress, plastic viscosity, storage modulus evolution, and build-up index, …
Circular Economy In Construction: Decision-Making Factors And Future Research Avenues, Bahaa Chammout, Islam H. El-Adaway
Circular Economy In Construction: Decision-Making Factors And Future Research Avenues, Bahaa Chammout, Islam H. El-Adaway
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The construction sector is a major consumer of raw materials and a significant contributor to environmental degradation. Circular economy (CE) - an economic and systemic approach aimed at minimizing waste and fostering sustainable resource use - offers a remedy for these impacts. However, CE adoption in construction remains under-researched and limited. Accordingly, there is a need to provide a comprehensive understanding of CE decision-making factors in construction. This paper addresses this research need. First, the authors reviewed 138 journal articles on CE in construction, published between 2015 and 2023, and compiled a comprehensive list of 40 factors influencing CE decision-making. …
Microstructural Evolution And Rheological Enhancement Of Asphalt–Rubber Binders: Unveiling The Role Of Morphology In Performance, Eslam Deef-Allah, Mohyeldin Ragab, Mohamed Attia, Magdy Abdelrahman
Microstructural Evolution And Rheological Enhancement Of Asphalt–Rubber Binders: Unveiling The Role Of Morphology In Performance, Eslam Deef-Allah, Mohyeldin Ragab, Mohamed Attia, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Understanding the development of an asphalt binder's internal network structure is essential when interacting asphalt and crumb rubber. Thus, the focus of this study was to reveal the development of asphalt–rubber binders' (A-RBs) network structures at different interaction times and their correlation with performance. Atomic force microscopy (AFM) was utilized to image the morphologies of the binders, and the binders' performances were explored rheologically with a dynamic shear rheometer. Extending the interaction time to 8 h and utilizing a soft binder altered the network structures from agglomerated dispersoids—minuscule distributed phase zones embedded in the continuous matrix of the asphalt binder—to …
Performance Evaluation Of Aminated Multi-Walled Carbon Nanotubes Incorporated With Green Synthesized Iron Nanoparticles For Toxic Dyes Sequestration From Textile Wastewater, Titus Chinedu Egbosiuba, Cynthia Chukwuemeka, Jonah Chukwudi Umeuzuegbu, Nwanneka Chibuzo Mmonwuba, Ugochukwu Ewuzie, Monday Uchenna Okoronkwo, Valentine Chikaodili Anadebe, Saheed Mustapha, Ambali Saka Abdulkareem, Jimoh Oladejo Tijani, Ashish Patel, Virendra Kumar Yadav
Performance Evaluation Of Aminated Multi-Walled Carbon Nanotubes Incorporated With Green Synthesized Iron Nanoparticles For Toxic Dyes Sequestration From Textile Wastewater, Titus Chinedu Egbosiuba, Cynthia Chukwuemeka, Jonah Chukwudi Umeuzuegbu, Nwanneka Chibuzo Mmonwuba, Ugochukwu Ewuzie, Monday Uchenna Okoronkwo, Valentine Chikaodili Anadebe, Saheed Mustapha, Ambali Saka Abdulkareem, Jimoh Oladejo Tijani, Ashish Patel, Virendra Kumar Yadav
Chemical and Biochemical Engineering Faculty Research & Creative Works
This study evaluates the performance of aminated multi-walled carbon nanotubes (AM-MWCNTs) integrated with zerovalent iron nanoparticles (ZVI) synthesized using cashew leaf (Anacardium occidentale) extract (AM-MWCNTs@ZVI) for the removal of Congo Red (CR) and Methylene Blue (MB) dyes from textile industrial wastewater. The nanocomposite was characterized using FTIR, XRD, BET, HRSEM, and HRTEM analyses, confirming its functional groups, crystalline structure, and enhanced surface area of 1050.4 m2/g. The ecological risk degree of the textile pollutants was assessed to determine the percentage concentrations of crystal violet, Congo red, methyl orange, methylene blue and rhodamine B. Batch adsorption experiments identified optimal …
Comparative Analysis Of Lab-Data-Driven Models For International Friction Index Prediction In High Friction Surface Treatment (Hfst), Alireza Roshan, Magdy Abdelrahman
Comparative Analysis Of Lab-Data-Driven Models For International Friction Index Prediction In High Friction Surface Treatment (Hfst), Alireza Roshan, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
High Friction Surface Treatments (HFSTs) are often utilized as a spot treatment to enhance selected areas with high friction demand rather than extended pavement sections and are helpful in increasing skid resistance and minimizing road accidents. A laboratory design approach was created to assess the fundamental ideas behind the international friction index (IFI) concept and update the present IFI model parameters for HFST applications based on test findings to gain a better understanding of HFST performance. Two aggregate types in three sizes were tested under controlled polishing cycles. Friction and texture were measured using the Dynamic Friction Tester (DFT) and …
Effect Of Coarse Aggregate On The Stability And Mechanical Performance Of Ultra-High Performance Concrete (Uhpc), Rui Zhong, Mingyan Pan, Hongyu Wu, Zhao Cheng, Jianzhong Liu, Jingquan Wang, Yiming Yao, Hongyan Ma
Effect Of Coarse Aggregate On The Stability And Mechanical Performance Of Ultra-High Performance Concrete (Uhpc), Rui Zhong, Mingyan Pan, Hongyu Wu, Zhao Cheng, Jianzhong Liu, Jingquan Wang, Yiming Yao, Hongyan Ma
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The effect of coarse aggregate (CA) on the stability and mechanical performance of ultra-high-performance concrete (UHPC) was investigated. To assess UHPC stability, a unique approach was developed that utilizes specially fabricated large specimens with a depth of 400 mm. It overcomes the drawback of limited CA migration distance using small specimens, which may not replicate conditions relevant to structural applications. The spatial distributions of various constituents along the vertical casting direction were quantified through image processing technology. Results showed an approximately 12 % reduction in CA content in the top layer, while the bottom layer exhibited 12 % more CA …