Architecture Commons^™

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

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 …

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 …

Some Insights On Flow Over Sharp-Crested Weirs Using Computational Fluid Dynamics: Implications For Enhanced Flow Measurement, Joseph M. Sinclair, S. Karan Venayagamoorthy, Timothy K. Gates

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study reexamines flow over a sharp-crested weir using computational fluid dynamics (CFD) to identify the optimal operating range under which the weir functions with accuracy as a free-flowing measurement device. A numerical parametric study was conducted for two separate channel and weir geometries under a range of flow rates resulting in different h/P values, where h is the elevation head over the weir crest, and P is the weir height. Analysis of velocity and pressure profiles over the weir revealed three distinct flow regimes: a high acceleration regime, an ideal operating regime, and a weir-inundated regime that may lead …

Seismic Risk Assessment Of A Steel Building Supported On Helical Pile Groups, Maryam Shahbazi, Amy B. Cerato, Emad M. Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Designing structures to be the least vulnerable within earthquake-prone areas is a serious challenge for structural engineers. One common and useful tool that structural engineers use to predict the vulnerability of a structure during an earthquake is a fragility curve. However, most structural fragility curves do not take into consideration the contribution of pile foundation systems in the structural vulnerability. Therefore, this study aims to modify existing fragility curves of a six-story fixed-base steel frame hospital building with buckling-restrained braces, to incorporate the effect of helical pile group behavior on the fragility of the structure. To that end, a finite …

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 …

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 …

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 …

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 …

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 …

Healthcare And Education Networks Interaction As An Indicator Of Social Services Stability Following Natural Disasters, Emad M. Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Healthcare and education systems have been identified by various national and international organizations as the main pillars of communities' stability. Understanding the correlation between these main social services institutions is critical to determining the tipping point of communities following natural disasters. Despite being defined as social services stability indicators, to date, no studies have been conducted to determine the level of interdependence between schools and hospitals and their collective influence on their recoveries following extreme events. In this study, we devise an agent-based model to investigate the complex interaction between healthcare and education networks and their overall recovery, while considering …

Orchestrating Performance Of Healthcare Networks Subjected To The Compound Events Of Natural Disasters And Pandemic, Emad M. Hassan, Hussam N. Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The current COVID-19 pandemic has demonstrated the vulnerability of healthcare systems worldwide. When combined with natural disasters, pandemics can further strain an already exhausted healthcare system. To date, frameworks for quantifying the collective effect of the two events on hospitals are nonexistent. Moreover, analytical methods for capturing the dynamic spatiotemporal variability in capacity and demand of the healthcare system posed by different stressors are lacking. Here, we investigate the combined impact of wildfire and pandemic on a network of hospitals. We combine wildfire data with varying courses of the spread of COVID-19 to evaluate the effectiveness of different strategies for …

The Bridge Newsletter Winter 2021, Missouri University Of Science And Technology

The Bridge Newsletter

-S&T contributes to infrastructure through national center
-Brinkmann leads Missouri Highways and Transportation Commission
-Wu wins NSF CAREER Award for 2D metals work
-Academy of Civil Engineers induction and 150^th celebration

Common Ground Newsletter Fall 2021, Missouri University Of Science And Technology

Common Ground

-Lighting the way with solar panel inspections
-CArEE Miner athletes score recognition
-Celebrating 150 years of civil engineering at S&T

Random Packing Material In Disinfection Contactors: Effects On Baffling And Energy Loss, Jessica L. Baker, Subhas K. Venayagamoorthy, Susan K. De Long

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the potential improvement in the hydraulic disinfection efficiency and the possible energy loss as a result of the presence of random packing material (RPM) in a laboratory-scale chlorine contactor. Tracer tests were conducted on a 55-gal drum tank filled with RPM in varying amounts in different configurations to measure the efficiency of each setup in terms of baffling factor (BF). The bulk pressure drop was measured to determine the energy loss for each configuration. The results of this study show that securing RPM near the inlet, in any amount, improves the BF by 300% to more than …

Achieving Domestic Internationalization And Global Competence Through On-Campus Activities And Globally Responsive Education, Sanjay Tewari, Peng Zhang, Yuan Zhuang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The impacts of the COVID-19 pandemic on students and educators are well known. However, there is a paucity of literature available on its impact on educational institutions in the context of their abilities to develop global competence in the middle of an ongoing pandemic. The virtual communication and remote delivery of educational content have been a popular trend for many universities to adapt to the pandemic challenges and re-think their internationalization strategies.

The limited travel opportunities because of the pandemic have highlighted a big need for the domestic internationalization mechanism at educational institutions. In this paper, the authors discuss how …

Early-Age Strength Of Co2 Cured Alkali-Activated Blast Furnace Slag Pastes, Yubin Jun, Seong Ho Han, Jae Hong Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The effect of CO₂ curing including pre-conditioning on alkali-activated slags, activated by different alkaline activators (NaOH, Na₂SiO₃, and KOH solution), is studied. While dry pre-conditioning before the CO₂ curing increases the strengths of all mixtures, the effect of pre-conditioning time is dependent on the alkali activator used to produce samples. The CO₃-bearing reaction product in samples also depends on the alkali activator. Gaylussite, pirssonite, hydrotalcite, and calcite are observed in the NaOH activator, and calcite, hydrotalcite, and C₄AcH₁₁ are detected in the NaOH and Na₂SiO₃ (9:1) …

Influence Of Seawater On Alkali-Activated Slag Concrete, Yubin Jun, Jae Hong Kim, Seong Ho Han, Taewan Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study examines the use of natural seawater as mixing water for alkali-activated slag concrete and reports the characteristics of alkali-activated slag concrete with exposure to seawater. Preliminary experiments were conducted on pastes in order to measure pH and select optimum activator content under the experimental conditions. Wet-sieved pastes from fresh concrete were used to evaluate the mineralogical and microstructural characteristics of reaction products. Compressive strengths and chloride contents were measured with the hardened concrete samples. The activators used in alkali-activated slag concrete were sodium hydroxide (5% weight of slag) and liquid sodium silicate (5% weight of slag). The alkali-activated …

Solar Panel Recycling In The United States, Divyesh Shelar

Undergraduate Research Conference at Missouri S&T

The last decade has seen enormous growth in the solar industry across the globe. According to the International Renewable Energy Agency (IREnA) in 2015 solar energy produced about 222 gigawatts worldwide with expected growth to top 4500 gigawatts by 2050. By comparison the United States is expected to see an additional 10.6 gigawatts in 2018. The Midwest has seen similar growth in the solar industry within the past decade. The problem is the technology used to convert the sun’s rays into electrical energy does not last forever. On average the industry rates a solar panel's life span around 25-30 years. …

Solar Panel Recycling In The United States, Hattie Matthews

Undergraduate Research Conference at Missouri S&T

The last decade has seen enormous growth in the solar industry across the globe. According to the International Renewable Energy Agency (IREnA) in 2015 solar energy produced about 222 gigawatts worldwide with expected growth to top 4500 gigawatts by 2050. By comparison the United States is expected to see an additional 10.6 gigawatts in 2018. The Midwest has seen similar growth in the solar industry within the past decade. The problem is the technology used to convert the sun’s rays into electrical energy does not last forever. On average the industry rates a solar panel's life span around 25-30 years. …

Spectral Induced Polarization Study On Enzyme Induced Carbonate Precipitations: Influences Of Size And Content On Stiffness Of A Fine Sand, Bate Bate, Junnan Cao, Chi Zhang, Na Hao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Heterogeneity in either chemically or microbiologically induced carbonate-based ground improvement methods is a major obstacle in engineering application. Spectral induced polarization (SIP), an innovative and nondestructive method, which has demonstrated promise in monitoring microbial activity, was used in this study to monitor enzyme induced carbonate precipitation (EICP). The complex conductivities, together with the shear wave velocities (Vs), of an EICP modified sand were monitored using a self-developed spectral induced polarization–bender element column. The mean precipitate size was calculated by relaxation time (τ) and the Schwarz equation. The precipitate contents were calculated by cumulative gamma distribution function on the global polarization …

Impact Of Multiple Waves Of Covid-19 On Healthcare Networks In The United States, Emad M. Hassan, Hussam N. Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The risk of overwhelming hospitals from multiple waves of COVID-19 is yet to be quantified. Here, we investigate the impact of different scenarios of releasing strong measures implemented around the U.S. on COVID-19 hospitalized cases and the risk of overwhelming the hospitals while considering resources at the county level. We show that multiple waves might cause an unprecedented impact on the hospitals if an increasing number of the population becomes susceptible and/or if the various protective measures are discontinued. Furthermore, we explore the ability of different mitigation strategies in providing considerable relief to hospitals. The results can help planners, policymakers, …

The Bridge Newsletter Spring 2021, Missouri University Of Science And Technology

The Bridge Newsletter

-Researchers investigate improved bridge repair after collisions
-White initiated as 132^nd honor member of Chi Epsilon
-Bereyso named New Face of Civil Engineering by ASCE
-150-year Celebration of Civil Engineering

Transdermal Uptake Of Benzophenone-3 From Clothing: Comparison Of Human Participant Results To Model Predictions, Azin Eftekhari, Jonathan T. Hill, Glenn C. Morrison

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Background: Models of transdermal uptake of chemicals from clothing have been developed but not compared with recent human subject experiments. In a well-characterized experiment, participants wore t-shirts pre-dosed with benzophenone-3 (BP-3) and BP-3 and a metabolite were monitored in urine voids. Objective: Compare a dynamic model of transdermal uptake from clothing to results of the human subject experiment. Methods: The model simulating dynamic transdermal uptake from clothing was coupled with direct measurements of the gas phase concentration of benzophenone-3 (BP-3) near the surface of clothing to simulate the conditions of the human subject experiment. Results: The base-case model results were …

Computational Analysis Of High Carbon Steel For Optimal Design, Muhammad Zubair, Aneela Wakeel, M. Mustafa Azeem, Aneeqa Tabbassum

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To increase the reliability of materials the computational analysis has been considered a vital tool for designing the components in the mechanical and nuclear engineering. By increasing a high percentage of carbon in liquid steel subsequently enhance the hardness, elasticity and toughness of the materials. In this research high carbon steel has been used due to its wear resistance properties in order to increasing hardness and strength. The findings of this research reveal the high carbon steel a good replacement material for conventional iron due to its low weight. Modeling and analysis of the steel, metallic glass and high carbon …

2020 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.

Shear Wave Velocity Anisotropy Of Salt- And Polymer-Amended Kaolinite, X. Kang, J. Cao, B. Bate

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Shear wave velocity (Vs) anisotropy of kaolinite mixed with sodium chloride (NaCl) and organic polymer (polyethylene oxide, xanthan gum, and chitosan) solutions was investigated using a custom-made floating wall consolidometer-type bender element testing system. The addition of salt and polymers influenced the microfabric anisoopy of platy kaolinite particles, thus resulted in the increment or decrement in the Vs anisotropy. The Vs of kaolinite in all three orthogonal directions increased as the NaCl concentration increased; however, the Vs anisotropy decreased. PEO and chitosan increased the Vs of kaolinite, while xanthan gum exhibited counter-effects. Vs anisotropy (Vs−hh/Vs−vh and Vs−hv/Vs−vh) of polymer amended …

The Bridge Newsletter Winter 2020, Missouri University Of Science And Technology

The Bridge Newsletter

-Kummers give largest single gift in the history of Missouri higher education
-$1M gift from the Sunderland Foundation completes ACML lab
-Miner alumni step up
-Academy of Civil Engineers inducts 11 new members

Resilience Of School Systems Following Severe Earthquakes, Emad M. Hassan, Hussam N. Mahmoud, Bruce R. Ellingwood

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Natural disasters may have catastrophic and long-lasting impacts on communities' physical, economic, and social infrastructure. Slow recovery of educational services following such events is likely to cause traumatic stress in children, lead families to out-migrate, and affect the community's overall social stability. Methods for quantifying and assessing the restoration process of educational systems and their dependencies on other supporting infrastructure have not received adequate attention. This study introduces, for the first time, a new framework to evaluate the functionality, recovery, and resilience of a school system following severe earthquake events. The framework considers both the quantity and quality of education …

Co2 Curing Efficiency For Cement Paste And Mortars Produced By A Low Water-To-Cement Ratio, Seong Ho Han, Yubin Jun, Tae Yong Shin, Jae Hong Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Curing by CO₂ is a way to utilize CO₂ to reduce greenhouse gas emissions. Placing early-age cement paste in a CO₂ chamber or pressure vessel accelerates its strength development. Cement carbonation is attributed to the quickened strength development, and CO₂ uptake can be quantitatively evaluated by measuring CO₂ gas pressure loss in the pressure vessel. A decrease in CO₂ gas pressure is observed with all cement pastes and mortar samples regardless of the mix proportion and the casting method; one method involves compacting a low water-to-cement ratio mix, and the other method comprises a …