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Articles 31 - 60 of 2023
Full-Text Articles in Structural Engineering
Evaluating Crumb Rubber Modified (Crm) Asphalt As A Sustainable Binder Alternative For High-Friction Surface Treatments, Abdallah Aboelela, Alireza Roshan, Magdy Abdelrahman
Evaluating Crumb Rubber Modified (Crm) Asphalt As A Sustainable Binder Alternative For High-Friction Surface Treatments, Abdallah Aboelela, Alireza Roshan, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
High-friction surface treatments (HFSTs) are widely applied to improve pavement safety by enhancing long-term skid resistance. Although epoxy resins are commonly used due to their strength and durability, their high cost, susceptibility to delamination, incompatibility with substrates of flexible pavements, and adverse environmental concerns limit their long-term performance. This study presents crumb rubber modified (CRM) asphalt as a sustainable alternative binder for HFST applications. CRM binders offer high performance and compatibility with existing pavement surfaces, cost effectiveness and reduced environmental impacts as compared to epoxy binders. In addition, the binder development utilizes enhanced recycling technologies for interacting with used tire …
Comparative Study Of Interfacial Bond Strength Of Steel H-Pile With Ultra-High Performance And Polymer Concrete Jacket, Binod Shrestha, Mohanad M. Abdulazeez, Mohamed A. Elgawady
Comparative Study Of Interfacial Bond Strength Of Steel H-Pile With Ultra-High Performance And Polymer Concrete Jacket, Binod Shrestha, Mohanad M. Abdulazeez, Mohamed A. Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study investigates the bond behavior of steel H-pile encased in concrete jackets under push-out loading, considering the effects of concrete type and embedment length. Nine full-scale specimens were tested using three concrete types: ultra-high-performance concrete (UHPC), Methyl Methacrylate Polymer Concrete (MMA-PC), and conventional concrete (CC), with embedment lengths of 63.5 mm, 127 mm, and 190.5 mm. The experimental results revealed that MMA-PC jacket demonstrated the highest bond strength, though gains were marginal beyond 127 mm. UHPC exhibited superior tensile strength and ductility, preventing splitting failure. UHPC also displayed the highest interfacial fracture energy of 9.63 N/mm, exceeding MMA-PC and …
Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat
Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The injection of carbon dioxide (CO2) into cementitious systems has emerged as a promising approach to enhancing sustainability in concrete production. This study explores the impact of CO2 injection on the rheological behavior, structural build-up, and particle size evolution of cement paste by systematically varying the water-to-cement ratio (w/c) (0.35, 0.4, and 0.5) and CO2 concentration (0.06, 0.28, and 0.84 mol). Rheological analysis revealed a significant increase in initial yield stress with CO2 injection. Using the Modified Bingham model, yield stress increased by 72 % and 150 % for 0.28- and 0.84-mol CO2, …
Interfacial Shear Transfer Between Steel H-Piles And Concrete Encased In Cfrp, Mohanad M. Abdulazeez, Binod Shrestha, Mohamed A. Elgawady
Interfacial Shear Transfer Between Steel H-Piles And Concrete Encased In Cfrp, Mohanad M. Abdulazeez, Binod Shrestha, Mohamed A. Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Numerous in-service steel H-piles, a common structural element in the bridge industry, suffer severe corrosion. One of the adopted solutions is to use concrete jackets to encase the corroded sections. Therefore, interfacial shear strength between the uncorroded section and the jacket is crucial. This paper presents an experimental investigation of the interfacial shear stresses of 18 full-scale H-piles encased in concrete jackets and subjected to push-out static testing. The concrete jackets are confined using different carbon fiber-reinforced polymer (CFRP) confinement ratios. Different cross-sectional areas and distributions of shear studs are investigated. The average and maximum bond stresses are evaluated and …
Experimental And Theoretical Studies Of Novel Resilient Smart Shear Keys For Speedy Functional Recovery Of Highway Bridges After Extreme Events, Xinzhe Yuan, Jun Han, Jian Zhong, Haibin Zhang, Genda Chen
Experimental And Theoretical Studies Of Novel Resilient Smart Shear Keys For Speedy Functional Recovery Of Highway Bridges After Extreme Events, Xinzhe Yuan, Jun Han, Jian Zhong, Haibin Zhang, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Sacrificial shear keys in small-to-medium-span highway bridges mainly provide lateral support to the bridge superstructure under extreme events such as earthquake and/or tsunami. However, such support could lead to irreparable harm to important bridge elements like abutments and bent caps (base), delaying the functional recovery of bridges in the aftermath. In addition, existing designs of the shear key primarily emphasize resistant capacity but overlook resilience. This study introduces a new sliding, modular, adaptive, replaceable, and two-dimensional (SMART) shear key designed to enhance the resilience of I-girder highway bridges. The SMART shear key has three primary goals: 1) enabling the rapid …
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 …
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, …
Understanding The Relationship Between Structural Failure And Fatalities In Tornadoes: A Quantitative Investigation Of The 2021 Midwest Tornado Outbreak, Yi Zhao, Ruwen Qin, John W. Van De Lindt, Justin Sharpe, Grace Yan
Understanding The Relationship Between Structural Failure And Fatalities In Tornadoes: A Quantitative Investigation Of The 2021 Midwest Tornado Outbreak, Yi Zhao, Ruwen Qin, John W. Van De Lindt, Justin Sharpe, Grace Yan
Engineering Management and Systems Engineering Faculty Research & Creative Works
During 1950-2011, the number of fatalities caused by tornadoes in the U.S. significantly exceeded the fatalities caused by both hurricanes and earthquakes. To reduce tornado induced fatalities, it is essential to understand how structures/building failures correlate with fatalities and who are more vulnerable to tornadoes. Insights from this study are intended to help provide information to decision-makers on where to allocate limited resources for enhancing tornado resilience. By examining both the fatality data and structural damage data in the 2021 Midwest Tornado Outbreak, the objective of this study is to examine the occurrence of fatalities during tornadoes across various types …
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 …
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 …
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 …
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 …
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.
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 …
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, …
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 …
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 Highly Modified Asphalt-Based Binders In High Friction Surface Treatment: Comparative Study With Epoxy-Based System, Alireza Roshan, Magdy Abdelrahman, Mohyeldin Ragab
Performance Evaluation Of Highly Modified Asphalt-Based Binders In High Friction Surface Treatment: Comparative Study With Epoxy-Based System, Alireza Roshan, Magdy Abdelrahman, Mohyeldin Ragab
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
High Friction Surface Treatments (HFSTs) are frequently used to increase skid resistance and reduce collisions, particularly in crash-prone zones, including horizontal curves and intersections. Epoxy-based binders traditionally have been the sole option for HFSTs, but their drawbacks, such as high costs and compatibility challenges, have led to the search for substitute binders, including asphalt-based options. This study investigates the comparative performance of highly modified asphalt-based binders, including polymer-modified, mastic, and highly modified emulsions, in HFST applications using two aggregate types, Calcined Bauxite (CB) and Rhyolite with different gradations, with an emphasis on their frictional properties, durability, and resistance to polishing. …
Fast Penetration Test As An In-Situ Method For Assessing Buildability In 3d Concrete Printing, Ali Fasihi, Nicolas Ali Libre
Fast Penetration Test As An In-Situ Method For Assessing Buildability In 3d Concrete Printing, Ali Fasihi, Nicolas Ali Libre
Miners Solving for Tomorrow Research Conference
No abstract provided.
Digital Fabrication With Fiber-Reinforced Concrete, Haodao Li, Kamal H. Khayat
Digital Fabrication With Fiber-Reinforced Concrete, Haodao Li, Kamal H. Khayat
Miners Solving for Tomorrow Research Conference
No abstract provided.
Underlying Mechanisms Of The Effect Of Microfines Of Manufactured Sand On Non-Linear Structural Build-Up Of Cement Paste, Jiang Zhu, Jiaping Liu, Kamal H. Khayat, Xin Cheng, Wei Zhao, Zhen Li, Xin Shu, Yongbo Huang
Underlying Mechanisms Of The Effect Of Microfines Of Manufactured Sand On Non-Linear Structural Build-Up Of Cement Paste, Jiang Zhu, Jiaping Liu, Kamal H. Khayat, Xin Cheng, Wei Zhao, Zhen Li, Xin Shu, Yongbo Huang
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The rheological properties of cement-based materials made with manufactured sand vary with the content and physio-chemical properties of microfines in the sand. However, the evaluation of rheological properties regarding the structural build-up at early-age hydration remains challenging for the cementitious materials prepared with different manufactured sands, due to complicated underlying structuration mechanisms. This paper studies the effect of disparate microfines of different manufactured sands on the non-linear growth of static yield stress of cement pastes at rest. The paste mixtures were prepared with 0.40 and 0.275 water-to-cement mass ratio (W/C) and had a fixed mini-slump flow of 240 ± 5 …
Quality Assurance Framework For Recovered Binders And Aggregates From Asphalt Mixtures Incorporating Recycled Materials, Eslam Deef-Allah, Magdy Abdelrahman
Quality Assurance Framework For Recovered Binders And Aggregates From Asphalt Mixtures Incorporating Recycled Materials, Eslam Deef-Allah, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study proposes that a proactive quality assurance (QA) framework for asphalt mixes with recycled materials, i.e., reclaimed asphalt pavement and recycled asphalt shingles, should be developed. Quality control (QC) is generally concerned with the contractor's obligation to produce mixes which meet the job mix formula (JMF) targets. However, QA considers the variability in fabrication processes and materials and offers monitoring by evaluating the contractor's performance. Although both aggregate gradations and asphalt contents were within the JMF specifications, the recovered binders revealed significant differences from the contract binders in the JMF. Rheological tests indicated increased stiffness and elasticity but reduced …
Impact Of Aggregate Characteristics On Frictional Performance Of Asphalt-Based High Friction Surface Treatments, Alireza Roshan, Magdy Abdelrahman
Impact Of Aggregate Characteristics On Frictional Performance Of Asphalt-Based High Friction Surface Treatments, Alireza Roshan, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
High Friction Surface Treatments (HFST) are recognized for their effectiveness in enhancing skid resistance and reducing road accidents. While Epoxy-based HFSTs are widely applied, they present limitations such as compatibility issues with existing pavements, high installation and removal costs, and durability concerns tied to substrate quality. As an alternative to traditional Epoxy-based HFSTs, this study investigated the effects of aggregate gradation as designated by agencies on the performance of asphalt-based HFST. Various aggregate types were assessed to evaluate friction performance and the impact of polishing cycles on non-Epoxy HFST. It was found that adjustments in aggregate size and gradation may …
Correlating The Compositional Changes To The Rheological Properties Of Recovered Asphalt Binders From Recycled Asphalt Mixtures: Insights From The Thermogravimetric Measurements, Eslam Deef-Allah, Magdy Abdelrahman
Correlating The Compositional Changes To The Rheological Properties Of Recovered Asphalt Binders From Recycled Asphalt Mixtures: Insights From The Thermogravimetric Measurements, Eslam Deef-Allah, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Assessing the binder performance of thermal characterization is critical for quality control. This is pertinent for recovered binders from mixtures, which may not be in adequate quantities to evaluate their performance, particularly in mixtures containing reclaimed asphalt pavement (RAP). The present study deployed a thermogravimetric analyzer to evaluate compositional changes in recovered binders from RAP-containing mixtures, focusing on thermograph and derivative of thermograph (DTG) characteristics and correlating the results to rheological features. Incorporating RAP in mixtures influenced recovered binders' DTG shapes, reducing low-combusted components (%LCC) and increasing residues (%R). The recovered binder from the zero-RAP-containing mixture showed a 4.36% increase …
Effect Of Shrinkage-Mitigating Materials, Fiber Type, And Repair Thickness On Flexural Behavior Of Beams Repaired With Fiber-Reinforced Self-Consolidating Concrete, Jingjie Wei, Kamal H. Khayat
Effect Of Shrinkage-Mitigating Materials, Fiber Type, And Repair Thickness On Flexural Behavior Of Beams Repaired With Fiber-Reinforced Self-Consolidating Concrete, Jingjie Wei, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
While self-consolidating concrete (SCC) has emerged as a highly effective approach for the repair of concrete structures, there have been few investigations regarding the effect of the combination of different fiber and shrinkage-mitigating material types (shrinkage-reducing admixture, SRA; superabsorbent polymer, SAP; and expansive agent, EA) on the flexural behavior of repaired structures. This study aims to explore the influence of three different shrinkage-mitigating materials (1.25%–2.5 % SRA, 4%–8% EA, and 0.2%–0.4 % SAP), four fiber types (two macro synthetic fibers, MSFA and MSFB; 5D hooked steel fibers, 5D; a combination of 80 % 3D hooked steel +20 % short steel …
Simulation-Based Models For Postearthquake Response: A Survey And Research Directions, Abhijit Gosavi, Lauryn A. Spearing, Lesley H. Sneed
Simulation-Based Models For Postearthquake Response: A Survey And Research Directions, Abhijit Gosavi, Lauryn A. Spearing, Lesley H. Sneed
Engineering Management and Systems Engineering Faculty Research & Creative Works
Computer simulation is increasingly being used by emergency planners as a tool to improve disaster response given that it can model real-world scenarios, such as earthquakes. Although there has been an increase in simulation research focused on disaster response, much of this literature is from disparate fields and across disaster scenarios. To bridge this gap, this paper surveys simulation-based models for post-earthquake response from the year 2000 onward. Advantages of simulation over closed-form statistical models are discussed. Three main subproblems in post-earthquake response models are explored: (1) service distribution (e.g., food, water), (2) infrastructure restoration (at the building and transportation …
Class-Wise Histogram Matching-Based Domain Adaptation In Deep Learning-Based Bridge Element Segmentation, Tarutal Ghosh Mondal, Zhenhua Shi, Haibin Zhang, Genda Chen
Class-Wise Histogram Matching-Based Domain Adaptation In Deep Learning-Based Bridge Element Segmentation, Tarutal Ghosh Mondal, Zhenhua Shi, Haibin Zhang, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study focused on the problem of domain shift in deep learning-based bridge element segmentation. The impracticability of accounting for all possible variabilities vis-à-vis structural shape, size, color, texture, illumination, and other operational conditions in the training process leads to the deterioration in the model performance when applied to test data from novel unseen domains. In such situations, rebuilding the model with labeled training data from the target domain becomes prohibitively expensive and time-consuming in many practical cases. Recent advancements in unsupervised domain adaptation techniques are known to provide viable solutions to this problem. However, it was observed in this …
Flexural Post-Cracking Performance Of Macro Synthetic Fiber Reinforced Super Workable Concrete Influenced By Shrinkage-Reducing Admixture, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat
Flexural Post-Cracking Performance Of Macro Synthetic Fiber Reinforced Super Workable Concrete Influenced By Shrinkage-Reducing Admixture, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Most literature has focused on the effect of shrinkage-reducing admixture (SRA) in shrinkage mitigation resistance of concrete. This study aims to examine the impact of SRA on the efficiency of macro synthetic fibers (MSF) in enhancing the flexural post-cracking behavior of fiber-reinforced super workable concrete (FR-SWC). A comparative analysis of the influence of fiber combinations on the flexural post-cracking behavior of beams is also included. Results showed that a higher dosage of SRA, particularly at 5 % by mass of binder, had a noticeable negative impact on flexural post-cracking performance of beams while exhibiting positive effect on workability and shrinkage …
Unmanned Vehicle Having Flight Configuration And Surface Traverse Configuration, Genda Chen, Alec Reven, Bo Shang, Zenhua Shi, Liujun Li, Boyang Li
Unmanned Vehicle Having Flight Configuration And Surface Traverse Configuration, Genda Chen, Alec Reven, Bo Shang, Zenhua Shi, Liujun Li, Boyang Li
Patents
An unmanned vehicle includes a body, at least one power source coupled to the body, a flight propulsion system coupled to the at least one power source and configured to propel the unmanned vehicle through air, and a surface propulsion system coupled to the at least one power source and configured to propel the unmanned vehicle along a surface. The unmanned vehicle is configured to switch between a flight configuration in which the unmanned vehicle is propelled through air via the flight propulsion system, and a surface traverse configuration in which the unmanned vehicle is propelled along the surface via …
Energy Dissipation Using Negative Stiffness Shells, Mohamed El-Gawady, Yasser Darwish
Energy Dissipation Using Negative Stiffness Shells, Mohamed El-Gawady, Yasser Darwish
Patents
A negative stiffness shell has a convex first position, but can transition or snap to a concave second position under a force applied to the exterior surface of the shell in the convex first position. During the transition, the shell exhibits negative stiffness that permits a large amount of energy to be absorbed. The negative stiffness shell can withstand a high initial force threshold prior to transitioning. In the second, concave position the shell can still resist force. Moreover, it is possible for the shell to revert back to the first, convex position with minimal plastic deformation for subsequent use. …