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Missouri University of Science and Technology

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Articles 31 - 60 of 1052

Full-Text Articles in Civil Engineering

Atomistic Insights Into Dual Mechanisms For Nacl-Driven Dissolution And Polymerization Of Tricalcium Silicate, Wei Zhang, Jia Sun, Juntao Dang, Bo Tao Huang, Biqin Dong, Hongyan Ma, Dongshuai Hou Oct 2025

Atomistic Insights Into Dual Mechanisms For Nacl-Driven Dissolution And Polymerization Of Tricalcium Silicate, Wei Zhang, Jia Sun, Juntao Dang, Bo Tao Huang, Biqin Dong, Hongyan Ma, Dongshuai Hou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, experimental characterization and reactive molecular dynamics simulations were integrated to reveal the effects of NaCl on the early hydration of tricalcium silicate (C3S). The results demonstrate that NaCl significantly accelerates the early hydration of C3S by promoting Ca dissolution and silicate tetrahedra polymerization. Specifically, Cl–ions coordinate with surface Ca, weakening the Ca–O bonds in C3S and reducing the energy barrier for Ca dissolution. Meanwhile, Na+ions compete with Ca2+for the O atoms, creating localized charge imbalance and attracting protons, which destabilize Si–O bonds and facilitate the polymerization of silicate tetrahedra. These effects …

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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 Oct 2025

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, …

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Carbonated High-Al Steel Slag As Supplementary Cementitious Material: Synergy Of Carbonation At Elevated Temperature And Addition Of Gypsum, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Lingyu Chi, Hongyan Ma Sep 2025

Carbonated High-Al Steel Slag As Supplementary Cementitious Material: Synergy Of Carbonation At Elevated Temperature And Addition Of Gypsum, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Lingyu Chi, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-Al steel slags, such as ladle metallurgy furnace (LMF) slag, substantially retard the early hydration of cement when incorporated into cement pastes, primarily due to the high mayenite content. In this study, carbonation of slag at elevated temperatures of 60°C and 80°C, combined with gypsum addition, was proposed to synergistically mitigate the retardation effect and enhance the early-age strength of cement pastes. The physical and chemical properties of slags carbonated at various temperatures were analyzed to elucidate their impact on cement performance as a supplementary cementitious material. The results indicate that higher temperatures enhance carbonation reactivity, accelerating the carbonation of …

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Magnesium Sulfate Attack Of Alite Paste And Mitigation By Surface Carbonation: Monitoring And Comparison Using Novel Portable Fiber-Optic Raman Probe, Bohong Zhang, Gao Deng, Hongyan Ma, Jie Huang Sep 2025

Magnesium Sulfate Attack Of Alite Paste And Mitigation By Surface Carbonation: Monitoring And Comparison Using Novel Portable Fiber-Optic Raman Probe, Bohong Zhang, Gao Deng, Hongyan Ma, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Sulfate attack on cement matrix is still a "confused world" especially when magnesium sulfate (MgSO4) is the sulfate source. Accurate assessment of sulfate attack is essential for evaluating the structural integrity and durability of concrete in relevant environments. This study presents a portable fiber-optic Raman probe approach with 125 μm spatial resolution, designed for depth-resolved sulfate ingress monitoring in tricalcium silicate (C₃S, Alite) pastes. The probe is also used to evaluate the effectiveness of surface carbonation in mitigating sulfate attack. The results demonstrate a strong correlation between sulfate penetration depth and Raman spectral intensity ratios of sulfate-related vibrational …

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Data-Driven Shear Capacity Prediction Of Studs Embedded In Uhpc For Steel-Uhpc Composite Structures, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen Sep 2025

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 …

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Amorphous Sio2-Stabilized High-Valent Iron-Oxo Complexes Derived From Fe- And Si-Rich Solid Wastes For Efficient Tetracycline Hydrochloride Degradation, Cuirong Yan, Hongyan Ma, Xiunan Cai, Zhongqiu Luo, Jinyu Shi, Wenhao Li, Xintao Zhou Sep 2025

Amorphous Sio2-Stabilized High-Valent Iron-Oxo Complexes Derived From Fe- And Si-Rich Solid Wastes For Efficient Tetracycline Hydrochloride Degradation, Cuirong Yan, Hongyan Ma, Xiunan Cai, Zhongqiu Luo, Jinyu Shi, Wenhao Li, Xintao Zhou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-valent iron-oxo complexes show promise as green oxidants for water remediation but suffer from critical limitations in stability and pH adaptability. Herein, we report a facile method to synthesize amorphous SiO2-stabilized high-valent iron-oxo complexes via Na+ diffusion activation of iron/silicon-rich copper smelting slag. In the complex, the synergistic coexistence of two distinct silica‑oxygen tetrahedral configurations-basic Na2SiO3 and acidic SiO2 oxides establishes a self-regulating pH buffering system that stabilizes solution neutrality. This unique structural design ensures sustained oxidative activity of the complex, representing a significant advancement over conventional silica-supported catalysts due to its intrinsic acid-base …

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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 Sep 2025

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 …

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Positive Effects Of Sulfates On Performance Of Cement Paste Incorporating Low-Grade, High-Aluminum Steel Slag, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Hongyan Ma Sep 2025

Positive Effects Of Sulfates On Performance Of Cement Paste Incorporating Low-Grade, High-Aluminum Steel Slag, Nannan Zhang, Gao Deng, Wenyu Liao, Chuanlin Hu, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel slag with high aluminum (Al) content significantly delays the early hydration of cement when used as a supplementary cementitious material (SCM). To address this challenge, this study investigates the effects of gypsum (Gy) and sodium sulfate (SS) additions on the performance of cement pastes with 30 % high-Al ladle metallurgy furnace (LMF) slag. The mechanical properties, hydration kinetics, phase evolution, as well as the early-age hydration mechanism were explored. The results indicate that C3S hydration is substantially inhibited under high-Al conditions, mainly attributed to the rapid dissolution and reaction of reactive aluminates (particularly mayenite) in the slag. Both Gy …

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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 Aug 2025

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 …

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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 Aug 2025

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 …

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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 Aug 2025

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 …

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Utilization Of Ftir-Atr For Material Characterization And Forensic Analysis, Helmut Leodarta, Ahmed S. El-Ashwah, Punyaslok Rath, Magdy Abdelrahman, William G. Buttlar Jul 2025

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 …

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Data-Driven Prediction Of Binder Rheological Performance In Rap/Ras-Containing Asphalt Mixtures, Eslam Deef-Allah, Magdy Abdelrahman Jul 2025

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 …

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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 Jul 2025

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 …

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Ftir Characterization Of Asphalt Sara Fractions In Response To Rubber Modification, Mohyeldin Ragab, Eslam Deef-Allah, Magdy Abdelrahman Jul 2025

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 …

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Treatment And Activation Effects On Kaolinite-Based Earth Concrete, Mojtaba Kohandelnia, Maroua Zerzouri, Ammar Yahia, Kamal H. Khayat Jun 2025

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, …

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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 Jun 2025

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 …

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Comparative Analysis Of Lab-Data-Driven Models For International Friction Index Prediction In High Friction Surface Treatment (Hfst), Alireza Roshan, Magdy Abdelrahman Jun 2025

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 …

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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 May 2025

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 …

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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 May 2025

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. …

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Polymetal Phosphate Cement From Tin Fuming Furnace Slag: Hydration Mechanism, Mechanical Performance, And Environmental Safety, Peiwen Lv, Xintao Zhou, Zhongqiu Luo, Cuirong Yan, Xiunan Cai, Ting Huang, Pingyan Wang, Hongyan Ma Apr 2025

Polymetal Phosphate Cement From Tin Fuming Furnace Slag: Hydration Mechanism, Mechanical Performance, And Environmental Safety, Peiwen Lv, Xintao Zhou, Zhongqiu Luo, Cuirong Yan, Xiunan Cai, Ting Huang, Pingyan Wang, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Phosphate cement materials are ideal binders for the rapid repairment of civil engineering and solidification/stabilization of hazardous solid wastes due to their fast setting, high early strength and strong adhesion. However, the use of pure metal oxides as the raw base materials and their deactive pretreatment result in the high cost and energy consumption, limiting its broad applications. In this study, an eco-friendly polymetal phosphate cement (PMPC) was developed using tin fuming furnace slag (TFFS) as the primary base material. The hydration behavior, microstructure, mechanical properties, and environmental safety of PMPC were comprehensively evaluated. The results showed that the hydration …

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Quality Assurance Framework For Recovered Binders And Aggregates From Asphalt Mixtures Incorporating Recycled Materials, Eslam Deef-Allah, Magdy Abdelrahman Apr 2025

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 …

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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 Apr 2025

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 …

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Impact Of Aggregate Characteristics On Frictional Performance Of Asphalt-Based High Friction Surface Treatments, Alireza Roshan, Magdy Abdelrahman Mar 2025

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 …

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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 Mar 2025

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 …

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Multi-Scale Modeling Of Transport Properties In Cementitious Materials With Go Admixture, Bing Liu, Weichen Kang, Weixing Lian, Feng Xing, Hongfang Sun, Hongyan Ma Feb 2025

Multi-Scale Modeling Of Transport Properties In Cementitious Materials With Go Admixture, Bing Liu, Weichen Kang, Weixing Lian, Feng Xing, Hongfang Sun, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In coastal areas, the presence of concrete cracks provides pathways for hazardous ions to ingress from the exterior into the interior of concrete, while the migration of the ions further accelerates concrete deterioration and causes durability problems. The incorporation of graphene oxide (GO) into concrete can inhibit crack initiation and development starting at the nanoscale, improving the concrete microstructure, thereby affecting concrete's resistance to hazardous ion transport and the resulting deterioration. In this study, a multi-scale transport model for cementitious materials with a GO admixture was established to predict the resistance to hazardous ions. Based on the determination of hydration …

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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 Feb 2025

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 …

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Performance And Economic Evaluation Of Asphalt-Based High Friction Surface Treatment (Hfst) Applications, Alireza Roshan, Magdy Abdelrahman Jan 2025

Performance And Economic Evaluation Of Asphalt-Based High Friction Surface Treatment (Hfst) Applications, Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High Friction Surface Treatments (HFSTs) are recognized for enhancing friction between tires and road surfaces, with reduced road accidents being a key benefit. Epoxy-based HFSTs, though widely used, come with challenges like compatibility issues with existing pavements, higher installation and removal costs, and reduced durability tied to substrate quality. Recently, state agencies have increasingly focused on developing asphalt-based alternative binders for HFST applications as highlighted in the National Cooperative Highway Research Program (NCHRP) RFP #NCHRP 10-145. This study introduces asphalt-based HFSTs as an alternative to traditional epoxy-based treatments. Various aggregate types were examined for friction performance and the effect of …

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

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

Doctoral Dissertations

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

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Flexural Post-Cracking Performance Of Macro Synthetic Fiber Reinforced Super Workable Concrete Influenced By Shrinkage-Reducing Admixture, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat Jan 2025

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 …

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