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- Rheology (7)
- Microstructure (5)
- UHPC (4)
- Compressive strength (3)
- Expansive agent (3)
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- Mechanical properties (3)
- Cable-stayed bridge (2)
- Carbon nanotube (2)
- Fiber alignment (2)
- Graphite nanoplatelet (2)
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- Infrastructure (2)
- Infrastructure management and system preservation (2)
- Internal resonance (2)
- Limestone calcined clay cement (2)
- Lubrication layer (2)
- Machine learning (2)
- Magnesium phosphate cement (2)
- Molecular dynamics (2)
- Numerical simulation (2)
- Object detection (2)
- Recycled materials (2)
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- Self-consolidating concrete (2)
- Shrinkage (2)
- Shrinkage reducing admixture (2)
- Superabsorbent polymer (2)
- 3D printing (1)
- 4-mm plates (1)
- Abrasion resistance (1)
Articles 61 - 82 of 82
Full-Text Articles in Architecture
Simplified Analytical Model To Assess Key Factors Influenced By Fiber Alignment And Their Effect On Tensile Performance Of Uhpc, Le Teng, Huanghuang Huang, Kamal Khayat, Xiaojian Gao
Simplified Analytical Model To Assess Key Factors Influenced By Fiber Alignment And Their Effect On Tensile Performance Of Uhpc, Le Teng, Huanghuang Huang, Kamal Khayat, Xiaojian Gao
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The increase in single-fiber pullout strength usually improves tensile strength and toughness of UHPC. An increase in fiber orientation angle (θ) up to 45° to the direction of pullout load was found to enhance the single-fiber pullout strength. However, such increase in predominant θ value along tensile strength specimens led to a reduction in tensile strength of UHPC. In order to elucidate this controversial observation, analytical models combined with experiments were carried out to assess the key factors influencing the tensile properties of UHPC due to variations of fiber orientation. The test parameters involved the evaluation of the effect of …
Influence Of Phosphorus Sources On The Compressive Strength And Microstructure Of Ferronickel Slag-Based Magnesium Phosphate Cement, Cuirong Yan, Hongyan Ma, Zhongqiu Luo, Xintao Zhou, Luxing Wang
Influence Of Phosphorus Sources On The Compressive Strength And Microstructure Of Ferronickel Slag-Based Magnesium Phosphate Cement, Cuirong Yan, Hongyan Ma, Zhongqiu Luo, Xintao Zhou, Luxing Wang
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Electric furnace ferronickel slag (EFS) is a typical magnesium-rich industrial by-product discharged from the manufacture of nickel and iron-nickel alloys. The approach to use it as the raw material for the preparation of magnesium phosphate cement (MPC) has potential and proves effec-tive. In this study, three different phosphorus sources (PS) including phosphoric acid (H3 PO4, PA), sodium dihydrogen phosphate (NaH2 PO4, SDP) and potassium dihydrogen phosphate (KH2 PO4, PDP) were used to react with EFS to prepare the EFS-based MPC (EMPC), and the effects of raw material mass ratio (EFS/PA, EFS/SDP, EFS/PDP) on the compressive strength, early hydration temperature and …
M&S Highlight: De Larrard Et Al. (1998) Fresh Concrete: A Herschel-Bulkley Material, Dimitri Feys
M&S Highlight: De Larrard Et Al. (1998) Fresh Concrete: A Herschel-Bulkley Material, Dimitri Feys
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
No abstract provided.
Understanding Effects Of Permafrost Degradation And Coastal Erosion On Civil Infrastructure In Arctic Coastal Villages: A Community Survey And Knowledge Co-Production, Min Liew, Ming Xiao, Louise Farquharson, Dmitry Nicolsky, Anne Jensen, Vladimir Romanovsky, Jana Peirce, Lilian Alessa, Christopher Mccomb, Xiong Zhang, Benjamin Jones
Understanding Effects Of Permafrost Degradation And Coastal Erosion On Civil Infrastructure In Arctic Coastal Villages: A Community Survey And Knowledge Co-Production, Min Liew, Ming Xiao, Louise Farquharson, Dmitry Nicolsky, Anne Jensen, Vladimir Romanovsky, Jana Peirce, Lilian Alessa, Christopher Mccomb, Xiong Zhang, Benjamin Jones
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper presents the results of a community survey that was designed to better under-stand the effects of permafrost degradation and coastal erosion on civil infrastructure. Observations were collected from residents in four Arctic coastal communities: Point Lay, Wainwright, Utqiaġvik, and Kaktovik. All four communities are underlain by continuous ice-rich permafrost with varying degrees of degradation and coastal erosion. The types, locations, and periods of observed permafrost thaw and coastal erosion were elicited. Survey participants also reported the types of civil infrastructure being affected by permafrost degradation and coastal erosion and any damage to residential buildings. Most survey participants reported …
Solving The Negative Earnings Dilemma Of Multistage Bidding In Public Construction And Infrastructure Projects: A Game Theory-Based Approach, Muaz O. Ahmed, Islam H. El-Adaway, Kalyn T. Coatney
Solving The Negative Earnings Dilemma Of Multistage Bidding In Public Construction And Infrastructure Projects: A Game Theory-Based Approach, Muaz O. Ahmed, Islam H. El-Adaway, Kalyn T. Coatney
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
With the tremendous increase in spending on public projects, contractors need to employ efficient and effective bidding strategies to cope with the competitive bidding environment. Usually, general contractors carry a portion of the work and subcontract other parts to eventually submit a holistic joint bid. This bidding setting is referred to as multistage bidding where subcontractors submit their quotations/bids to the general contractor, after which the general contractor submits a final joint bid for the whole project. In a multistage bidding environment, general contractors may be faced with an increase in the probability of negative or below normal profits. Despite …
Design, Dynamic Performance And Ecological Efficiency Of Fiber-Reinforced Mortars With Different Binder Systems: Ordinary Portland Cement, Limestone Calcined Clay Cement And Alkali-Activated Slag, Wu Jian Long, Zhuorui Wu, Kamal Khayat, Jingjie Wei, Biqin Dong, Feng Xing, Jinrui Zhang
Design, Dynamic Performance And Ecological Efficiency Of Fiber-Reinforced Mortars With Different Binder Systems: Ordinary Portland Cement, Limestone Calcined Clay Cement And Alkali-Activated Slag, Wu Jian Long, Zhuorui Wu, Kamal Khayat, Jingjie Wei, Biqin Dong, Feng Xing, Jinrui Zhang
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The dynamic mechanical properties and ecological efficiency of cement-based composites are of vital importance to the development of green building materials and dynamic loadings resistance. In this study, the dynamic mechanical properties, ecological and economic efficiency of fiber-reinforced mortars (FRMs) made with different binder systems, including ordinary Portland cement (OPC), limestone calcined clay cement (LC3), and alkali-activated slag (AAS), were compared. In addition, different rheological parameters were designed to evaluate the dynamic mechanical properties of FRMs. The fiber pull-out testing, Barrett-Joyner-Halenda (BJH) testing, and scanning electron microscope (SEM) were used to reveal the difference in the dynamic mechanical properties of …
Dynamical Properties Of Environmental High-Performance Composites With Calcined Clay, Jingjie Wei, Wu Jian Long, Kamal Khayat, Biqin Dong, Liu Mei, Feng Xing
Dynamical Properties Of Environmental High-Performance Composites With Calcined Clay, Jingjie Wei, Wu Jian Long, Kamal Khayat, Biqin Dong, Liu Mei, Feng Xing
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Concrete structures may be exposed to dynamic loadings within short periods such as earthquakes and vehicles load, resulting in substantial damage to human life and property because of the collapse of concrete structures. The research achievements on dynamic properties of high-performance composites with LC3 (HPC-LC3) are limited, although dynamic loadings are commonly encountered in infrastructure. The study aims to develop a new-green concrete product (HPC-LC3) with high dynamical properties and promote its mass use in a vibration service environment by investigating dynamical properties of HPC-LC3. Dynamical properties of structure can be promoted at material level by means of enhancing the …
Novel Tri-Viscous Model To Simulate Pumping Of Flowable Concrete Through Characterization Of Lubrication Layer And Plug Zones, Tooran Tavangar, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat
Novel Tri-Viscous Model To Simulate Pumping Of Flowable Concrete Through Characterization Of Lubrication Layer And Plug Zones, Tooran Tavangar, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In this study, computational fluid dynamics (CFD) was employed to simulate the pipe flow of 18 self-consolidating and four highly workable concrete mixtures in a 30-m long pumping circuit. Pressure loss (ΔP) in 100- and 125-mm diameter (DP) pipelines was measured under low (1.2–6.2 l/s) and high (8.1–16.4 l/s) flow rates (Q). The numerical simulation was successfully carried out using a two-fluid model and a new variable-viscosity single-fluid approach, namely double-Bingham and tri-viscous models, respectively. The radial variation of rheological properties of the concrete across the pipe section, representing the plug flow, sheared concrete, and lubrication layer (LL) zones was …
Water Film Depth Prediction Model For Highly Textured Pavement Surface Drainage, Alireza Pourhassan, Ahmed A. Gheni, Mohamed Elgawady
Water Film Depth Prediction Model For Highly Textured Pavement Surface Drainage, Alireza Pourhassan, Ahmed A. Gheni, Mohamed Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Water film depth (WFD) is an important factor for road traffic safety because of its direct connection with skid resistance, hydroplaning speed, and the tendency of splash and spray. Increasing the pavement macrotexture reduces WFD. However, existing models for WFD prediction have not been developed on highly textured surfaces such as chip seal. Furthermore, the rainfall intensities used for developing most of these models were relatively low, leaving no or low WFD on chip seal surfaces. To propose a WFD prediction model suitable for highly textured surfaces and to consider the effect of surface material type, an experimental study was …
Setting Times Of Early-Age Mortars Determined From Evolution Curves Of Poisson’S Ratio, Bate Bate, Xiao Chen, Chao Chen, Hongyan Ma, Jianfeng Zhu, Junnan Cao, Jiakai Chen, Kamal Khayat, Shuai Zhang
Setting Times Of Early-Age Mortars Determined From Evolution Curves Of Poisson’S Ratio, Bate Bate, Xiao Chen, Chao Chen, Hongyan Ma, Jianfeng Zhu, Junnan Cao, Jiakai Chen, Kamal Khayat, Shuai Zhang
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Setting times, as the early-age properties of cement-based materials, are important properties to ensure the quality and long-term performance of engineering structures. To determine the initial and final setting times of cementitious materials, the compressive wave velocity and shear wave velocity of six early-age mortar samples were monitored. Their time evolution curves of Young's modulus, shear modulus, bulk modulus, and Poisson's ratio were then calculated and analyzed. The signature times of the derivatives of the Poisson's ratio evolution curves correlate well with the initial and final setting times, and the remarkably high coefficient of determination values relative to the data …
Management Of Change Orders In Infrastructure Transportation Projects, Rayan H. Assaad, Muaz O. Ahmed, Islam H. El-Adaway, Pramen P. Shrestha
Management Of Change Orders In Infrastructure Transportation Projects, Rayan H. Assaad, Muaz O. Ahmed, Islam H. El-Adaway, Pramen P. Shrestha
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The Illinois Department of Transportation (IDOT) will handle many upcoming projects due to the recent statewide infrastructure strategic plan and the fast-track efforts affecting many infrastructure projects amid COVID-19. Nevertheless, many change orders are anticipated to occur on IDOT's projects. Thus, this paper examines the proper contractual management of changes within IDOT infrastructure transportation projects by following a research method based on the integration between a desktop analysis and a focus group analysis. The desktop analysis involved collecting information and data from existing resources, case studies, and documents related to change orders. The focus group analysis involved consulting with change …
Viscosity Modifying Agents: Key Components Of Advanced Cement-Based Materials With Adapted Rheology, Hela Bessaies-Bey, Kamal Khayat, Marta Palacios, Wolfram Schmidt, Nicolas Roussel
Viscosity Modifying Agents: Key Components Of Advanced Cement-Based Materials With Adapted Rheology, Hela Bessaies-Bey, Kamal Khayat, Marta Palacios, Wolfram Schmidt, Nicolas Roussel
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Viscosity modifying agents (VMAs) are essential ingredients for the production of flowable cement-based materials. This paper presents an overview of commonly used VMAs and attempts to shed some light on the underlying physics at the origin of their mechanisms of action. The main molecular parameters of VMA controlling the rheological properties of the cement pore solution are highlighted. As the mechanisms of action of VMAs in cement-based materials are closely related to their affinity with the surface of cement particles, the adsorption of the main VMA types is discussed. The effect of VMAs on flow properties and stability of cement-based …
Developing Mix Proportions For Class C Fly Ash-Based Alkali-Activated 3d-Printed Concrete Mixtures, Fareh Abudawaba, Eslam Gomaa, Ahmed Gheni, Mohamed Elgawady
Developing Mix Proportions For Class C Fly Ash-Based Alkali-Activated 3d-Printed Concrete Mixtures, Fareh Abudawaba, Eslam Gomaa, Ahmed Gheni, Mohamed Elgawady
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study investigated the use of class C fly ash (FA) as a precursor for alkali-activated mortar (AAM) for 3D-printed concrete (3DPC). AAMs with different water-to-FA (W/FA), alkaline activator-to-FA (Alk/FA), and sodium silicate-to-sodium hydroxide (SS/SH) ratios were examined to develop mixtures that can be tailored for different structural applications of 3DPC. The fresh properties, including extrudability and buildability, were evaluated through the open time (OT) and immediate deformation tests, respectively. Different cycle times (CTs) were applied to achieve a strain limit state necessary to maintain the printed shape. The strength of AAMs in different directions at different CTs was examined. …
Examining The Effect Of A Chitosan Biopolymer On Alkali-Activated Inorganic Material For Aqueous Pb(Ii) And Zn(Ii) Sorption, Sukanta K. Mondal, Chenglin Wu, Felix C. Nwadire, Ali A. Rownaghi, Aditya Kumar, Yusuf Adewuyi, Monday Uchenna Okoronkwo
Examining The Effect Of A Chitosan Biopolymer On Alkali-Activated Inorganic Material For Aqueous Pb(Ii) And Zn(Ii) Sorption, Sukanta K. Mondal, Chenglin Wu, Felix C. Nwadire, Ali A. Rownaghi, Aditya Kumar, Yusuf Adewuyi, Monday Uchenna Okoronkwo
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Biopolymers and alkali-activated materials have attracted a great deal of attention as adsorbents for the removal of heavy metal contaminants from aqueous solutions. Both materials are sustainable and feature unique properties, but biopolymers are relatively more expensive or difficult to prepare and exhibit low mechanical and surface properties, a narrow pH range, and thermal stability. In this study, hybrid adsorbents were prepared from both types of material, by alkali activation of low-cost fly ash precursors accompanied by incorporation of 0-2%mass chitosan biopolymer. Two types of alkaline activating solutions, NaOH and Na2SiO3, were employed to generate two sets of hybrid adsorbents …
Molecular Insight Into The Fluidity Of Cement Pastes: Nano-Boundary Lubrication Of Cementitious Materials, Muhan Wang, Kaixuan Zhang, Xiang Ji, Pan Wang, Hongyan Ma, Jun Zhang, Dongshuai Hou
Molecular Insight Into The Fluidity Of Cement Pastes: Nano-Boundary Lubrication Of Cementitious Materials, Muhan Wang, Kaixuan Zhang, Xiang Ji, Pan Wang, Hongyan Ma, Jun Zhang, Dongshuai Hou
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The workability mechanism of fresh concrete at the molecular level remains essentially unexplored. To understand the molecular origin for cement fluidity, molecular dynamics and Density Function Theory (DFT) were utilized to construct a shear model of Calcium-Silicate-Hydrate (C-S-H) layers. The structure, dynamics, and reactivity of ultra-confined pore solution between C-S-H gels are systematically investigated. Under shear loading, periodic oscillation of friction force is observed as the typically Couette flow and the interfacial friction force is reduced from 35.2 Kcal/mol·Å to 3.3 Kcal/mol·Å with water content increasing. All of the systems contain breakage of noncovalent bonds of water-Ca and water-water in …
Effect Of Type And Content Of Expansive Agent On Performance Of Fiber-Reinforced Concrete With Adapted Rheology, Ahmed Abdelrazik, Kamal Khayat
Effect Of Type And Content Of Expansive Agent On Performance Of Fiber-Reinforced Concrete With Adapted Rheology, Ahmed Abdelrazik, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
A performance-based mixture design approach was utilized to optimize the binder content and composition for fiber-reinforced super workable concrete (FR-SWC) and fiber-reinforced self-consolidating concrete (FR-SCC). The test parameters included the replacement ratio of the cement by a Class C fly ash (FA), type and content of expansive agent (EA), and total binder content. Hooked-end steel fibers measuring 30 mm in length were used at 0.5% by volume. The investigated concrete was tested for slump flow, modified J-ring, sieve stability, bleeding, visual stability index, air content, unit weight, as well as compressive and splitting tensile strengths. The elastic modulus, autogenous, drying …
Parenting Pre-Teens During Covid-19 In A Rural Midwestern Community: An Interpretive Phenomenological Study, Sarah Oerther, Daniel B. Oerther
Parenting Pre-Teens During Covid-19 In A Rural Midwestern Community: An Interpretive Phenomenological Study, Sarah Oerther, Daniel B. Oerther
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
To uncover the experiences of parenting Generation Z pre-teen children in rural communities impacted by the Stay Home Missouri order from April through May 2020. Researchers have focused on urban parents, leading to gaps in understanding the impact of the COVID-19 quarantine on rural parents and children. A qualitative study employing interpretive phenomenology. 14 white cis-male-sexed fathers and cis-female-sexed mothers living in midwestern rural communities participated in this study. Semi-structured interviews with 14 participants parenting pre-teen children were conducted. The interviews were analyzed using interpretive phenomenology. The COREQ checklist was followed. One theme that emerged from the narratives was the …
Fan-Shaped Model For Generating The Anisotropic Catchment Area Of Subway Stations Based On Feeder Taxi Trips, Shiwei Liu, Yajuan Deng, Xianbiao Hu, Jiaxing Zhou, Jianming Chen
Fan-Shaped Model For Generating The Anisotropic Catchment Area Of Subway Stations Based On Feeder Taxi Trips, Shiwei Liu, Yajuan Deng, Xianbiao Hu, Jiaxing Zhou, Jianming Chen
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The catchment areas of subway stations have always been considered as a circular shape in previous research. Although some studies show the catchment area may be affected by road conditions, public transportation, land use, and other factors, few studies have discussed the shape of the catchment area. This study focuses on analyzing the anisotropy of catchment areas and developing a sound methodology to generate them. Based on taxi global positioning system (GPS) data, this paper first proposes a data mining method to identify feeder taxi trips around subway stations. Then, a fan-shaped model is proposed and applied to Xi'an Metro …
Bcmnet: Cross-Layer Extraction Structure And Multiscale Downsampling Network With Bidirectional Transpose Fpn For Fast Detection Of Wildfire Smoke, Jiayong Li, Guoxiong Zhou, Aibin Chen, Chao Lu, Liujun Li
Bcmnet: Cross-Layer Extraction Structure And Multiscale Downsampling Network With Bidirectional Transpose Fpn For Fast Detection Of Wildfire Smoke, Jiayong Li, Guoxiong Zhou, Aibin Chen, Chao Lu, Liujun Li
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
At present, the wildfire smoke detection algorithm based on YOLOv3 has problems, such as low accuracy and slow detection speed. In this article, we propose a cross-layer extraction structure and multiscale downsampling network with bidirectional transpose FPN (BCMNet) for fast detection of wildfire smoke. First, a cross-layer extraction module, which combines linear feature multiplexing and receptive field amplification, is designed. It can improve the speed and accuracy of wildfire smoke detection. Second, a multiscale downsampling module with different convolution kernels and maximum pooling operation is designed to preserve the details of the image while downsampling. Then, a bidirectional transposed FPN …
Resonance Analysis Between Deck And Cables In Cable-Stayed Bridges With Coupling Effect Of Adjacent Cables Considered, Houjun Kang, Yunpeng Cai, Yunyue Cong, Xiaoyang Su, Guirong Grace Yan
Resonance Analysis Between Deck And Cables In Cable-Stayed Bridges With Coupling Effect Of Adjacent Cables Considered, Houjun Kang, Yunpeng Cai, Yunyue Cong, Xiaoyang Su, Guirong Grace Yan
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The nonlinear dynamic model of a shallow arch with multiple cables is developed to model a long-span cable-stayed bridge. Based on the veering phenomenon of cable-stayed bridges, the in-plane modal internal resonance between the first mode of the shallow arch and the first mode of the cable is investigated under both primary resonance and subharmonic resonance. Modulation equations of the dynamic system are obtained by Galerkin discretization and the multiple scales method, in which the equilibrium solution of modulation equations is obtained by the Newton–Raphson method. Meanwhile, the Runge–Kutta method is applied to directly solve the ordinary differential equations to …
Impact Of Deicers On Low-Temperature Performance Of Missouri Pavements, Jun Liu, Yizhuang David Wang, Farshad Kerahroudi Saberi, Jenny Liu
Impact Of Deicers On Low-Temperature Performance Of Missouri Pavements, Jun Liu, Yizhuang David Wang, Farshad Kerahroudi Saberi, Jenny Liu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The use of deicer chemicals for highway winter maintenance operations is an essential strategy for ensuring a reasonably high level of service. It's critical to quantify their effectiveness and potentially detrimental effects on transportation infrastructure (i.e., asphalt and concrete pavements). In this study, nine deicer chemicals used in the state of Missouri were collected. The ice-melting test was conducted to quantify the performance characteristics of deicer chemicals. Freeze-thaw (F-T) test of concrete in the presence of deicer was conducted to quantify the negative effects of deicers to concrete. Low-temperature behavior of asphalt mixture affected by deicers was quantified by asphalt …
Optimizing Exterior Lighting Illuminance And Spectrum For Human, Environmental, And Economic Factors., S. M. Simmons, Stuart Werner Baur, William L. Gillis, Devin Michael Burns, Heath Pickerill
Optimizing Exterior Lighting Illuminance And Spectrum For Human, Environmental, And Economic Factors., S. M. Simmons, Stuart Werner Baur, William L. Gillis, Devin Michael Burns, Heath Pickerill
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
With the recent widespread adoption of LED lighting in outdoor areas, numerous concerns have been raised about the potential for harmful effects on humans, animals, plants, and the night sky. These stem from the high blue light content of some LED bulbs and an incentive to increase lighting levels caused by higher efficiency and lower costs. While new lighting installations are often described as environmentally friendly due to their energy efficiency, factors such as light pollution are often neglected or not given enough weight. This research focuses on optimizing the design of exterior lighting for human, environmental, and economic factors …