Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation, 2024 Missouri University of Science and Technology
Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation, Le Teng, Ming Jin, Jiadi Du, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Thin bonded ultra-high-performance concrete (UHPC) overlay is an advanced technology for bridge deck rehabilitation. UHPC should be tailored to secure adequate flowability and high thixotropy to facilitate mixing and placement with a low risk of sagging of the material on sloped bridge deck surfaces. The synergetic effect between nano clay (NC) and polycarboxylate ether (PCE) superplasticizer or cellulose-based viscosity modifying admixture (VMA) and PCE on the rheological properties (yield stress, plastic viscosity, and thixotropy), cement hydration, autogenous shrinkage, compressive strength, and porosity was systematically investigated. The bond strength between conventional concrete (CC) representing existing bridge deck concrete and thixotropic UHPC …
A Review Of Whipple Shield Ballistic Limit Equations, 2024 Missouri University of Science and Technology
A Review Of Whipple Shield Ballistic Limit Equations, S. Ryan, W. (William) P. Schonberg
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Ballistic limit equations (BLEs) are semi-analytical expressions used to predict the risk posed by micrometeoroid and orbital debris (MMOD) impacts on a spacecraft. A foundational BLE, known as the new non-optimum (NNO) equation was published by Eric Christiansen of NASA Johnson Space Center in 1990 for application on Whipple shields – two-plate configurations consisting of a thin sacrificial plate located at some standoff in front of the spacecraft pressure hull or structural wall. Today, BLEs for almost all multi-plate spacecraft structures, e.g., honeycomb sandwich panels, monolithic structures with thermal insulation blankets, etc., are based on the NNO Whipple BLE. We …
Utilizing Biomimicry To Design Sustainable Architecture, 2024 University of Arkansas, Fayetteville
Utilizing Biomimicry To Design Sustainable Architecture, Virginia Hammond
Architecture Undergraduate Honors Theses
Nature has an integral relationship with architecture and serves as a sustainable role model and inspiration for designers. The process of biomimicry in architecture has the potential to produce more sustainable design solutions and foster a connection between humans and nature. Existing biomimetic design projects have varying strengths and weaknesses as examples of the process. Utilizing guidelines and references from key leaders in biomimetic design consultancy (Biomimicry 3.8), selected case studies are assessed for their ability to demonstrate the benefits of this design strategy. Using these evaluations, the case studies are diagrammed and critiqued to determine how new projects could …
Methodology To Design Eco-Friendly Fiber-Reinforced Concrete For 3d Printing, 2024 Missouri University of Science and Technology
Methodology To Design Eco-Friendly Fiber-Reinforced Concrete For 3d Printing, Haodao Li, Alfred Addai-Nimoh, Eric Kreiger, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Greater use of locally available supplementary cementitious materials (SCM) to reduce cement content and addition of fiber reinforcement can enhance the performance of 3D printing (3DP) technology in construction. In this study, three classes of eco-friendly 3D printable fiber-reinforced mixtures were targeted, namely ultra-high-performance concrete (UHPC), high-performance concrete (HPC), and conventional concrete (CC). A step-by-step methodology was proposed to maximize the substitution rate of cement with SCM and limestone filler and optimize fiber volume for the successful development of 3D printable fiber-reinforced materials. Binder combinations were initially investigated on the paste level to determine the packing density and robustness. Selected …
Characterization Of Alkali-Silica Reaction (Asr) Products And C-S-H Using Swir Spectroscopy For Nondestructive Detection Of Asr, 2024 Missouri University of Science and Technology
Characterization Of Alkali-Silica Reaction (Asr) Products And C-S-H Using Swir Spectroscopy For Nondestructive Detection Of Asr, Pengfei Ma, Wenyu Liao, Ying Zhuo, Hongyan Ma, Yanping Zhu, Genda Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study explores the feasibility of characterizing alkali-silica reaction (ASR) products and calcium silicate hydrates (C-S-H) from short-wave infrared (SWIR) spectroscopy. ASR products and C-S-H samples with different Ca/Si ratios were synthesized and analyzed through XRD, 29Si nuclei magnetic resonance (NMR) and SWIR spectroscopy. Fourier-transform infrared spectroscopy (FTIR) was collected to help interpret the results from the SWIR spectroscopy. The obtained spectroscopic features were applied to quantify the ASR product abundance denoted by the length expansion of mortar bars after an accelerated ASR test. The results show that the SWIR spectra of the synthetic ASR gels are similar regardless of …
Evolution Of Sbs-Modified Asphalt Performance Under Aging And Rejuvenation Cycle Conditions, 2024 Missouri University of Science and Technology
Evolution Of Sbs-Modified Asphalt Performance Under Aging And Rejuvenation Cycle Conditions, Ke Shi, Feng Ma, Jenny Liu, Zhen Fu, Ruimeng Song, Dongdong Yuan, Aboudou Wassiou Ogbon
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Improving the poor long-term service performance of rejuvenated SBS-modified asphalt (REF-LT) is highly challenging. In this study, a blend of aged and virgin binders was used to rejuvenate REF-LT and the evolution of the asphalt performance was observed during regeneration and reaging processes. An SBS-modified asphalt (SBM) and base asphalt (BA) were mixed with REF-LT in specified ratios to prepare SBM- and BA-rejuvenated asphalts. The rejuvenated asphalts were subjected to short- and long-term aging. The high/low-temperature rheological properties, fatigue resistance, rejuvenation mechanism, and changes in the functional groups of the rejuvenated and reaged asphalts were characterized using a dynamic shear …
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, 2024 Missouri University of Science and Technology
Numerical And Experimental Investigation Of Negative Stiffness Beams And Honeycomb Structures, Yasser Darwish, Mohamed A. Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Metamaterial structures that exhibit negative stiffness (MSNS) behavior have shown the potential to be used as energy dissipation systems in different applications. Negative stiffness honeycomb structures consist of multiple pre-buckled beams that snapping through from one pre-buckled mode to another buckled mode, when subjected to transverse loads, displaying negative stiffness, and dissipating a significant portion of the input energy. This paper presents finite element models (FEMs) developed to investigate the performance of negative stiffness pre-buckled beams and honeycombs. The FEMs were validated using experimental results of single pre-buckled beams and honeycomb structures. The experimental testing of the pre-buckled beams was …
Synergistic Effect Of Macro Synthetic Fiber And Shrinkage-Reducing Admixture On Engineering Properties Of Fiber-Reinforced Super-Workable Concrete, 2024 Missouri University of Science and Technology
Synergistic Effect Of Macro Synthetic Fiber And Shrinkage-Reducing Admixture On Engineering Properties Of Fiber-Reinforced Super-Workable Concrete, Jingjie Wei, Nima Farzadnia, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study aims to enhance fiber-reinforced super-workable concrete (FR-SWC) by optimizing the system of shrinkage-reducing admixture (SRA) and macro-synthetic fiber (MSF) for low shrinkage and uncompromised mechanical properties. A factorial design approach was employed to model the effect of fiber content, SRA dosage, and combined ratios of two types of MSF on performance of FR-SWC. MSF content had the greatest impact on mechanical properties, followed by SRA and MSF combination. Using MSF increased equivalent flexural strength ratio by 310% compared to the control mixture, regardless of MSF combination and SRA. SRA had the most significant effect on drying shrinkage, followed …
Use Of Hybrid Fibers And Shrinkage Mitigating Materials In Scc For Repair Applications, 2024 Missouri University of Science and Technology
Use Of Hybrid Fibers And Shrinkage Mitigating Materials In Scc For Repair Applications, Kamran Aghaee, Kamal H. Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Self-consolidating concrete (SCC) is used to repair structural elements with congested reinforcement or restricted access to placement and consolidation. In addition to adequate flowability, passing ability, filling capacity, and stability, adequate bonding to the substrate and reinforcing bars, low shrinkage and cracking resistance are required for successful repair. This study employs various shrinkage mitigating materials, including expansive agent (EA), coupled use of EA with shrinkage reducing admixture (SRA), and EA with pre-saturated lightweight sand (LWS) to fulfill these requirements. The effect of these materials on the performance of SCC made with a hybrid synthetic (PP) fiber and a hybrid steel-synthetic …
The Influence Of Green Building Design On Tourists' Intention To Stay In Eco-Friendly Hotels: A Study On Perceptions And Preferences, 2024 Modern University for Technology and Information, Egypt-
The Influence Of Green Building Design On Tourists' Intention To Stay In Eco-Friendly Hotels: A Study On Perceptions And Preferences, Enas Al Sayed Salama Dr., Gehad Nasr Abdelsalam Dr.
Journal of Engineering Research
Green building design involves integrating sustainable and environmentally friendly practices into the construction and operation of buildings, including hotels, with the goal of minimizing the adverse impact on the environment. This paper delves into the pivotal role of green building design and eco-service provision within the context of green hotels. The aim is to investigate the interconnections among tourists' environmental concerns, their perceived significance of green building design, and their intention to choose green hotels.
To enhance the understanding of tourist behavior and its implications for tourism in Egypt, a questionnaire was administered in Sharm El Sheikh, a prominent Egyptian …
Using Biomimicry To Increase Daylighting Efficiency In Egyptian Office Buildings, 2024 Modern university for technology and information
Using Biomimicry To Increase Daylighting Efficiency In Egyptian Office Buildings, . Nervana Osama Hanafy
Journal of Engineering Research
The aim is to design a biomimicry-inspired building skin for Giza City's business towers. Tasks to complete include enhancing daylighting efficiency and promoting visual comfort To improve the daylighting performance of office buildings in Giza City, Egypt, this article presents 144 alternatives for biomimicry-inspired building skin to improve daylighting efficiency and visual comfort for Giza City's business towers For modeling, Revit, Rhino v6, and Grasshopper were utilized. The suggested daylighting simulation application, ClimateStudio (v1.8.8244.25334), was chosen. The building orientation, used materials, surface level measurement, working hours, and pertinent weather file data have all been provided. The evaluation criteria include Annual …
Visual Privacy As An Approach To Improve Human Needs In Residential Buildings In Egypt, 2024 Tanta University
Visual Privacy As An Approach To Improve Human Needs In Residential Buildings In Egypt, Inas Samir Ibrahim, Walaa Nour, Mustafa Alwan
Journal of Engineering Research
Architecture reflects a nation’s cultural, social, and environmental characteristics. As a result of the recent globalization, countries have lost their distinctive architectural identities; due to this, it is difficult to identify A country’s unique identity locally and regionally. Specifically, in Egypt, houses in the traditional style are considered one of the most iconic architectural styles. There is an amazing local identity and a unique spatial quality in the region that characterizes Egypt. On the other hand, Western influences have caused many of the values and attributes of houses to fade. One of the most prominent values is the home’s loss …
The Effect Of Building Information Modeling Technology On The Future Of Architecture Education Development In Universities, 2024 Tanta University - Faculty of Engineering - Postgraduate studies
The Effect Of Building Information Modeling Technology On The Future Of Architecture Education Development In Universities, Mohamed Abd Elnaser Hamoda, Mahmoud Ahmed Zaki, Marwa Ahmed Kamer Faculty Of Engineering, Tanta University
Journal of Engineering Research
At the beginning of the current century , and with the development of computer technology , a new system based on three-dimensional drawings and modeling appeared with an accurate definition and description of all the elements in the submitted design , with the big development of construction methods and the advancement of the related technology and software, the advantages of the new system were defined and became more specific and relied in many organizations , companies and in design and construction institutions , and this system was called the building information modeling (BIM) .
Despite the importance of the system …
Comparative Analysis Between The Performance Of Vernacular Articulations And Enhanced Architectural Articulations -Case Study Mashrabiya –, 2024 Tanta University - Faculty of Engineering
Comparative Analysis Between The Performance Of Vernacular Articulations And Enhanced Architectural Articulations -Case Study Mashrabiya –, Reham Elsayed Altobaa, Ayman Gamal Abdeltawab, Walaa Mehanna
Journal of Engineering Research
Abstract- Architectural heritage is a powerful image of the community's identity and is only a natural result of human interaction with the surrounding environment. heritage–based -architectural articulations are a way to achieve human comfort in certain conditions and environments. This paper discusses the relationship between architectural heritage and community identity.
It also analyses the different parameters of vernacular articulations and enhanced vernacular articulations that control indoor human thermal comfort. In addition, the paper focuses on the factors affecting these articulations such as airflow, wind, temperature regulation, and light control. the results of this analytical process indicate how design configurations of …
The Interpretative Structural Modeling For Stakeholder Involvement To Reduce Slum Settlements, 2024 Universitas Indonesia, Faculty of Engineering, Civil Engineering Department
The Interpretative Structural Modeling For Stakeholder Involvement To Reduce Slum Settlements, Bich Hanes Bich, Ayomi Dita Rarasati
Smart City
The array of problems originating from slum settlements not only results in unwholesome environment, unlawful land utilization, and various internal challenges within the vicinity but also impacts the surrounding regions and the overall urban infrastructure network. In pursuit of Indonesia's 2045 Vision, which emphasizes on "equitable and integrated infrastructure development", the zero slums constitutes a pivotal component of the Ministry of Public Works and Public Housing's overarching vision. Nonetheless, a disparity has been identified in addressing slum settlements in West Kalimantan, hindering the achievement of this objective. This research aims to identify the stakeholders and the priority factors in determining …
Mechanism Of Seismic Liquefaction For Heterogeneous Soil, 2024 California Polytechnic State University, San Luis Obispo
Mechanism Of Seismic Liquefaction For Heterogeneous Soil, Radu Popescu, Pradipta Chakrabortty
Architectural Engineering
In addition to inducing uncertainty in the predicted response, natural spatial variability of soil properties affects the mechanical response of geotechnical structures. When a failure surface is involved in the response, this surface can deviate from its theoretical location to pass through weaker zones of material. For the case of seismically induced soil liquefaction, it has been found that a larger amount of excess pore water pressure is generated in a soil exhibiting small-scale variability of its properties than in the corresponding uniform soil having geomechanical properties equal to the average properties of the heterogeneous soil. An explanation for this …
The Hydration, Microstructure, And Mechanical Properties Of Vaterite Calcined Clay Cement (Vc³), 2024 Missouri University of Science and Technology
The Hydration, Microstructure, And Mechanical Properties Of Vaterite Calcined Clay Cement (Vc³), Yaqiang Li, Yue Li, Hongyan Ma, Jiaqi Li
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Limestone (calcite) calcined clay cement (LC3) is a promising low-CO2 binder, but the low activity of calcite cannot compensate the reduction in clinker factor, resulting in low one-day strength and limiting its broad applications. As recent carbon capture and utilization technologies allow scalable production of vaterite, a more reactive CaCO3 polymorph, we overcome the challenge by introducing vaterite calcined clay cement (VC3), inspired by the vaterite-calcite phase change. In the present study, VC3 exhibits higher compressive strengths and faster hydration than LC3. Compared to hydrated LC3, hydrated VC3 exhibits increased amount of hemi- and mono-carboaluminate formation and decreased amount of …
Prediction Of Self-Consolidating Concrete Properties Using Xgboost Machine Learning Algorithm: Part 1–Workability, 2023 Missouri University of Science and Technology
Prediction Of Self-Consolidating Concrete Properties Using Xgboost Machine Learning Algorithm: Part 1–Workability, Amine El Mahdi Safhi, Hamed Dabiri, Ahmed Soliman, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Interest in Implementing Self-Consolidating Concrete (SCC) in Major Construction Projects Has Increased Significantly in Recent Years. This Paper Reports the Results of an Extensive Survey of Experimental Data of More Than 1700 SCC Mixtures from over 100 Studies Published in the Last Decade. the Survey Included the SCC Mixture Proportioning, Key Fresh Properties Including Flowability, Passing Ability, and Segregation Resistance, as Well as Some of the Derived Properties (E.g., Paste Volume). the Statistical Analysis of the Reported Parameters Showed Wide Variations in Values. the Outcome of the Survey Indicates that SCC Mixture Design and Workability Properties Do Not Systematically …
Design And Performance Of Fiber-Reinforced Shrinkage Compensating Eco-Friendly Concrete, 2023 Missouri University of Science and Technology
Design And Performance Of Fiber-Reinforced Shrinkage Compensating Eco-Friendly Concrete, Kamran Aghaee, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Eco-Crete is an ecological and economical concrete that benefits from high packing density of solid materials and reduced paste. Eco-Crete can enhance the service life of structures by reducing the risk of shrinkage cracking. In this study, shrinkage mitigating materials included an expansive agent (EA), a shrinkage reducing admixture (SRA), and a lightweight sand (LWS), as well as steel and synthetic fibers were used to minimize the risk of cracking. A total of 35 fiber-reinforced Eco-Crete mixtures were prepared with 350 kg/m3 of cementitious materials and 55 % substitution of fly ash and slag. Key fresh and mechanical properties in …
Effect Of A Geothermal Heat Pump System On Cooling Residential Buildings In A Hot, Dry Climate, 2023 The British University in Egypt
Effect Of A Geothermal Heat Pump System On Cooling Residential Buildings In A Hot, Dry Climate, Rania Rushdy Moussa, Ayman H. Mahmoud
Architectural Engineering
ABSTRACT In the last century, electricity demand has doubled due to urban expansion, which has contributed to the formation of more urban heat islands (UHI) and the appearance of environmental hazards such as the global climate change phenomenon. Since residential buildings are considered the main electricity consumer sector in Egypt, they consume up to 42% of total energy consumption, which contributes to increasing temperatures and constitutes UHI in cities. In this context, the research aims to examine the effectiveness of using the closed vertical loop geothermal system (GSHPCV) for cooling residential buildings in a hot, dry climate, such as Cairo, …