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Full-Text Articles in Engineering

Implementation Of The Linear Amplitude Sweep Test To Evaluate Fatigue Resistance Of Highly Polymerized Asphalt Binders, Jun Liu, Yizhuang David Wang, Jenny Liu May 2022

Implementation Of The Linear Amplitude Sweep Test To Evaluate Fatigue Resistance Of Highly Polymerized Asphalt Binders, Jun Liu, Yizhuang David Wang, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Highly polymerized asphalt binders (HPABs) such as PG 64-40 have been increasingly used in cold regions such as Alaska in recent years. However, there are currently considerable data gaps when it comes to the characterizations of the HPABs, especially their fatigue behaviors. The objective of this study is to apply the linear amplitude sweep (LAS) test with the viscoelastic continuum damage (VECD) model to assess the fatigue resistance of HPABs. Three HPABs (PG 52-40, PG 64-40, and PG 52-46) and one unmodified binder (PG 52-28) were used in the study. The fatigue failure during LAS tests on HPABs was defined, …


Linking Bad Credentials To Safety Issues, Andrew Martin, Jeeyen Koo, Valerie Keathley-Helil, Mallory Brown, Jennifer Walton May 2022

Linking Bad Credentials To Safety Issues, Andrew Martin, Jeeyen Koo, Valerie Keathley-Helil, Mallory Brown, Jennifer Walton

Kentucky Transportation Center Research Report

This study assesses (1) the effectiveness of the Kentucky Automated Truck Screening (KATS) system, (2) the relationship between credential and vehicle safety violations, (3) the relationship between credential and driver safety violations, and (4) the relationship between credential violations and crashes. The KATS system, which is installed at weigh stations throughout the Commonwealth of Kentucky, is highly effective at detecting KYU, IFTA, and UCR violations with sensitivities of 80.54, 87.56, and 88.28 percent, respectively. However, the system is less effective at detecting IRP violations (sensitivity = 20.83 percent). There is a statistically significant relationship between credentialing and vehicle safety violations, …


Improving Flood Inundation And Streamflow Forecasts In Snowmelt Dominated Regions, Irene Garousi-Nejad May 2022

Improving Flood Inundation And Streamflow Forecasts In Snowmelt Dominated Regions, Irene Garousi-Nejad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Much effort has been dedicated to expanding hydrological forecasting capabilities and improving understanding of the continental-scale hydrological modeling used to predict future hydrologic conditions and quantify consequences of climate change. In 2016, the National Oceanic and Atmospheric Administration’s (NOAA) Office of Water Prediction implemented the National Water Model (NWM) to provide nationally consistent, operational hydrologic forecasting capability across the continental U.S. The primary goal of this research was to develop hydrological tools that include modeling of flood inundation mapping and snowmelt contributions to river flow in snowmelt-dominated regions across the Western U.S. This dissertation first presents terrain analysis enhancements developed …


Advancing Data Collection, Management, And Analysis For Quantifying Residential Water Use Via Low Cost, Open Source, Smart Metering Infrastructure, Camilo J. Bastidas Pacheco May 2022

Advancing Data Collection, Management, And Analysis For Quantifying Residential Water Use Via Low Cost, Open Source, Smart Metering Infrastructure, Camilo J. Bastidas Pacheco

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Urbanization, climate change, aging infrastructure, and the cost of delivering water to residential customers make it vital that we achieve a higher efficiency in the management of urban water resources. Understanding how water is used at the household level is vital for this objective.Water meters measure water use for billing purposes, commonly at a monthly, or coarser temporal resolutions. This is insufficient to understand where water is used (i.e., the distribution of water use across different fixtures like toilets, showers, outdoor irrigation), when water is used (i.e., identifying peaks of consumption, instantaneous or at hourly, daily, weekly intervals), the efficiency …


Evaluation Of Human And Ecological Water Management Tradeoffs In A Seasonal Watershed With Spatially-Distributed Demands, Jesse Lee Rowles May 2022

Evaluation Of Human And Ecological Water Management Tradeoffs In A Seasonal Watershed With Spatially-Distributed Demands, Jesse Lee Rowles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River managers must balance the needs of the ecosystems that rely on the river by leaving water instream, often while also considering human demands. It is especially difficult to balance these water needs in systems that are highly seasonal and have no instream storage (e.g., reservoirs) since water cannot be stored for use throughout the year. An example of a watershed that has both of these characteristics is the South Fork Eel River in coastal northern California. In order to evaluate tradeoffs between human and ecological demands in this system, a water allocation model with water management scenarios and environmental …


Assessing The Role Of Magnetite In Municipal Wastewater Treatment, Patricia Ayaa May 2022

Assessing The Role Of Magnetite In Municipal Wastewater Treatment, Patricia Ayaa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Some municipal wastewater treatment (MWWT) facilities have adopted magnetite in their treatment processes through a technology called BioMag® to meet effluent regulatory requirements for total nitrogen and total phosphorus. However, there is limited information on the mechanisms and efficiency of magnetite in the removal of nitrogen (N) and phosphorus (P) from wastewater. This research, therefore, estimated its effectiveness in the removal of these nutrients, with a case study of the Marlay-Taylor Water Reclamation Facility in Maryland. The intervention analysis model was used, but a new forecasting approach to the model was proposed to fit the data in this study and …


Network-Wide Pedestrian And Bicycle Crash Analysis With Statistical And Machine Learning Models In Utah, Md Rafiur Rahman May 2022

Network-Wide Pedestrian And Bicycle Crash Analysis With Statistical And Machine Learning Models In Utah, Md Rafiur Rahman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent trends in crashes indicate a dramatic increase in both the number and share of pedestrian and bicyclist injuries and fatalities nationally and in many states. Crash frequency modeling was undertaken to identify crash prone characteristics of segments and non-signalized intersections and explore possible non-linear associations of explanatory variables with crashes. Crowdsourced “Strava” app data was used for bicycle volume, and pedestrian counts estimated from nearby signalized intersections were used as pedestrian volume. Multiple negative binomial models investigated crashes at different spatial scales to account for different levels of data availability and completeness. The models showed high traffic volume, steeper …


Advances In Process Understanding And Methods To Support River Temperature Modeling In Large Regulated Systems, Bryce A. Mihalevich May 2022

Advances In Process Understanding And Methods To Support River Temperature Modeling In Large Regulated Systems, Bryce A. Mihalevich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River temperatures play a key role in determining the suitability of habitat for aquatic ecosystems. While thermal regimes are influenced by many factors, flow and temperature patterns in large rivers are often shaped by water development. As such, water management associated with large reservoirs and diversions have also altered aquatic ecosystems. As climate change introduces new climate and hydrologic patterns, the decisions water managers make to address changes in runoff may further impact aquatic ecosystems. This calls for robust modeling tools that can predict river and reservoir temperature responses to water management decisions over large regions. However, highly variable topography …


Evaluation Of Hydrograph Separation Techniques With Uncertain End-Member Composition, Eileen Page Lukens May 2022

Evaluation Of Hydrograph Separation Techniques With Uncertain End-Member Composition, Eileen Page Lukens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to precipitation and temperature occurring as a result of climate change can influence water sources (such as groundwater or snowmelt) that contribute to stream flow in a watershed. This is significant, as shifts in the amount of water coming from different water sources can shape watershed management decisions. One technique often used to investigate changes in water sources is hydrograph separation, a mathematical tool that allows for the quantification of the amount of water that came from different water sources. However, it can be difficult to perform hydrograph separations in remote watersheds as there may be insufficient infrastructure, i.e. …


Using Experiments, 3d Scanning, And Computational Fluid Dynamics To Analyze Variance In Minor Loss Coefficients, Adam B. Pack May 2022

Using Experiments, 3d Scanning, And Computational Fluid Dynamics To Analyze Variance In Minor Loss Coefficients, Adam B. Pack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As water moves through pipes, it loses energy. The energy losses are due to friction and the minor losses associated with various pipe fittings, which change the direction of flow. Pipe bends, or elbows, are a common pipe fitting and a significant source of energy loss in piping systems. This research was performed to better understand the variability of energy loss due to different pipe elbow designs and to investigate methods to replicate these losses using numerical simulations.

Eight pipe elbows, all 3-inch, 90-degree, schedule 40 PVC elbows that vary by radius of curvature and/or end connection type, were tested …


Exploring The Effects Of Upstream Disturbances On Elbow Meter Performance With Numerical Modeling Applications, Riley D. Manwaring May 2022

Exploring The Effects Of Upstream Disturbances On Elbow Meter Performance With Numerical Modeling Applications, Riley D. Manwaring

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Physical data was collected for a 6-in. long-radius elbow meter in order to determine the effects of certain upstream disturbances on its metering performance. Discharge coefficients are calculated for each of the three tested configurations at various installation distances between the upstream disturbance and the elbow meter. Computational Fluid Dynamics (CFD) software was used to determine which turbulence models most accurately modeled the observed physical results in order to provide a base from which to model the effects of additional upstream disturbances not modeled in this study.


Long Term Feasibility Of Inductive Power Transfer Systems Embedded In Concrete Pavement Panels, Nathan J. Raine May 2022

Long Term Feasibility Of Inductive Power Transfer Systems Embedded In Concrete Pavement Panels, Nathan J. Raine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electric vehicles (EVs) have a variety of issues that prevent widespread acceptance. Range limitations, charging times, and lack of accessible locations are all viable concerns when considering the future of EVs. This research seeks to address lack of useable infrastructure and battery life by embedding wireless chargers directly into roadway concrete. These embedded chargers would make it possible to charge an EV while it is in transit, addressing many concerns associated with owning an EV.

Embedding a wireless charger, or Inductive Power Transfer System (IPTS), can cause premature failure in the concrete. To determine the long-term feasibility of the technology, …


Electrochromic Windows: Return On Investment Analysis, Thomas Michael Caprio May 2022

Electrochromic Windows: Return On Investment Analysis, Thomas Michael Caprio

Construction Management

In recent years, sustainability in construction has become a topic of undeniable interest. With sustainability certifications becoming more prominent and desirable, members of the construction industry have begun to seek alternatives for standard systems to keep up with market trends. One of the main issues that the construction industry faces is accessibility of technology. While there are new products and technologies being released frequently, members of the construction industry lack knowledge on the specific details and implications of working with newer systems. One piece of technology that was recently introduced is electrochromic glass, or smart glass. Electrochromic windows analyze sunlight …


Installation Of Electrical System For Paso Robles Police Department, Peter D. Strykers, Jacob M. Studebaker May 2022

Installation Of Electrical System For Paso Robles Police Department, Peter D. Strykers, Jacob M. Studebaker

Construction Management

This paper outlines the process that Peter Strykers and Jacob Studebaker went through to set up the lighting and power system for the Paso Robles Police Department gun range located off highway 46. Before our installation, the gun range had zero lighting so the officers could not use it after sunset. We allowed the officers to light the gun range with outdoor LED lights, light up both the storage units on site, and have access to multiple outlets inside and out of the storage units. The power source that the electrical system runs on comes from a Kubota generator because …


Application Of Lanthanides In Wastewater Treatment And Water Reuse, George William Kajjumba May 2022

Application Of Lanthanides In Wastewater Treatment And Water Reuse, George William Kajjumba

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the world’s population feed on grains (wheat, rice, and corn). Corn is as sensitive as it is productive. This thirsty, fast-growing plant goes into thermal shock in drought. In 2014, California lost over $2.2 billion in crop production due to drought. The Horn of Africa (in 2011) and Sahel (in 2012) faced humanitarian disasters due to food and water scarcity. The higher frequency of climate change and the erratic nature of rain, combined with underlying economic and social vulnerabilities, has meant that food and water scarcity is here to stay. To improve food and water scarcity, water reclamation …


Behavior Of Axially-Restrained Reinforced Concrete Beams Under High Sustained Loads, Ghazaleh Mehdikhan Laleh May 2022

Behavior Of Axially-Restrained Reinforced Concrete Beams Under High Sustained Loads, Ghazaleh Mehdikhan Laleh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Following column failure in a reinforced concrete (RC) frame structure, a progressive collapse may result if the beams supported by the failed column cannot generate an alternate path to carry the redistributed gravity loads. Past studies of the collapse resistance of RC frame beams were limited to their short-time load-carrying capacity. Axially restrained frame beams experience a compressive arch action as a beneficial load-resisting mechanism not considered in a conventional structural design. Due to the compressive arch action, the column failure may not cause an immediate collapse; however, gravity loads still act on the damaged structure, inducing high sustained stresses …


Investigating The Resilience Of Accessibility To Emergency And Lifesaving Facilities Under Natural Hazards, Chih-Hao Wang, Na Chen May 2022

Investigating The Resilience Of Accessibility To Emergency And Lifesaving Facilities Under Natural Hazards, Chih-Hao Wang, Na Chen

Mineta Transportation Institute

Studying accessibility, including the resilience of city transportation networks, is critical to understand how these networks influence individuals’ mobility and lives. This study developed an analytical research framework to examine the resilience of accessibility to emergency and lifesaving facilities under the threats of natural hazards such as earthquakes and wildfires. With a cumulative-opportunity approach, the authors measured accessibility by counting emergency and lifesaving facilities (including parks, schools, hospitals, roads, and fire stations) that can be reached by driving at the census tract level in San Fernando Valley, CA. With the calculated accessibility, the authors run simulations to collect data showing …


Structural Design For Fire Conditions Of A Prototype Metal Building Using The New Proposed Appendix To Aisi S100, Xia Yan, Thomas Gernay May 2022

Structural Design For Fire Conditions Of A Prototype Metal Building Using The New Proposed Appendix To Aisi S100, Xia Yan, Thomas Gernay

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

Performance-based design for fire conditions has been increasingly adopted for different structural systems over the last decade. The objective of this project is to exemplify through a case study how the newly proposed Appendix 4 to AISI S100 [1] on ‘Structural Design for Fire Conditions’ could be used by the metal building industry. The scope of work on the project includes the following:

(1) Identification of a prototype metal building to serve as an exemplar case study for the structural fire design procedure.

(2) Definition of the performance objectives and design requirements for the building in the fire situation. This …


Precast Concrete Manufacturing Business Plan, John F. Will Jr. May 2022

Precast Concrete Manufacturing Business Plan, John F. Will Jr.

Construction Management

The Central Coast of California has been under development since the Great Recession of 2008. Throughout this development, there has been an exceedingly high demand for precast concrete products, specifically in the civil sector of the construction industry. These products are being utilized by more and more by contractors around the world. This demand has emerged from the lack of concrete product manufacturers in this region of California. This project introduces a business plan for a new precast concrete product manufacturer by the name of J.W. Concrete Products LLC. The objective of this business plan is to reflect the benefits …


Paso Robles Police Department Shooting Range Shade Structure, Evan Marshall Cogswell May 2022

Paso Robles Police Department Shooting Range Shade Structure, Evan Marshall Cogswell

Construction Management

The Paso Robles Police Department has been a partner for multiple senior projects working to develop improvements for their shooting range. The shooting range is used extensively by officers year-round, with the climate being hot in the summer and rainy in the winter. We wanted to provide a shade structure located between the two shipping containers used for storage so that the officers would have a sheltered place to provide instruction, clean their weapons, and rest in between rounds on the range. This type of project was new to all three of us in the group – Parker Smith, Kevin …


Installation Of Electrical System For Paso Robles Police Department, Jacob M. Studebaker, Peter D. Strykers May 2022

Installation Of Electrical System For Paso Robles Police Department, Jacob M. Studebaker, Peter D. Strykers

Construction Management

This paper outlines the process that Peter Strykers and Jacob Studebaker went through to set up the lighting and power system for the Paso Robles Police Department gun range located off highway 46. Before our installation, the gun range had zero lighting so the officers could not use it after sunset. We allowed the officers to light the gun range with outdoor LED lights, light up both the storage units on site, and have access to multiple outlets inside and out of the storage units. The power source that the electrical system runs on comes from a Kubota generator because …


Forecasting Salinity In The Laguna Madre Using Deep Learning, Martin J. Flores Jr. May 2022

Forecasting Salinity In The Laguna Madre Using Deep Learning, Martin J. Flores Jr.

Theses and Dissertations

Salinity is an important metric in the Laguna Madre for establishing the long term health of the local ecological population. By utilizing Deep Learning (DL) techniques, the predicted and forecasted salinity in the Laguna Madre is generated from data provided by the Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua satellite.

Currently, only one other DL model has been used to forecast Sea Surface Salinity (SSS), being a Recurrent Neural Network (RNN). However, the RNN model requires the prediction of a full area of salinity to function.

As such, several model architectures were tested, with the best one, being a Multi-input MPNN, utilized …


Experimental And Numerical Analysis Of Soil-Geosynthetic Composite For A Geosynthetic-Reinforced Roadway System, Daniel Robertson May 2022

Experimental And Numerical Analysis Of Soil-Geosynthetic Composite For A Geosynthetic-Reinforced Roadway System, Daniel Robertson

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The present research conducted tests to evaluate the reinforcing performance of geosynthetics including three geogrids (GG1, GG2, and GG3) and one geotextile (GT) for three different soil types – sand, clay, and red shale. All geosynthetics showed great improvement under the lowest confining pressure. The report concluded that between the Large-Scale Direct Shear test, the Large-Scale Pullout Box, and the FLAC simulation, the three geogrids showed the greatest improvement when conducted with sand. The sand could withstand a much greater normal pressure than either clay or red shale. The biaxial geogrids, GG1 and GG3, had ideal results for lower stress …


Utilizing Shockwave Theory And Deep Learning To Estimate Intersection Traffic Flow And Queue Length Based On Connected Vehicle Data., Abdulmaged Algomaiah May 2022

Utilizing Shockwave Theory And Deep Learning To Estimate Intersection Traffic Flow And Queue Length Based On Connected Vehicle Data., Abdulmaged Algomaiah

Electronic Theses and Dissertations

The development of Connected Vehicles (CV) facilitates the use of trajectory data to estimate queue length and traffic volume at signalized intersections. The previously proposed models involved additional information that may require conducting different types of data collection. Also, most models need higher market penetration rate or more than a vehicle per cycle to provide adequate estimation. This is mainly because a significant number of the estimation models utilized only queued vehicles. However, the state of motion in non-queued vehicles, particularly slowed-down vehicles, provides much information about the traffic characteristics. There is a lack of exploiting the information from slowed-down …


Quantitative Holistic Assessment Of Implementing Collaborative Planning Practices, Amr Elsayegh, Islam H. El-Adaway May 2022

Quantitative Holistic Assessment Of Implementing Collaborative Planning Practices, Amr Elsayegh, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Practices of collaborative planning - as related to novel project delivery methods, information technologies, lean construction, and supply chain practices - can impact the cost and schedule performance of projects in the architectural, engineering, and construction (AEC) industry. However, there is a lack of research providing a quantitative holistic assessment of implementing collaborative planning practices. This paper fills this knowledge gap. Using an interdependent multistep research methodology, the authors (1) analyzed a holistic literature-based list of collaborative planning risks using 46 responses from industry expert surveys; (2) calculated the criticality of these risks and compared the obtained results using Spearman …


For The Improvement Of Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment Using Carbon Nanotube And Graphite Nanoplatelet, Huanghuang Huang, Le Teng, Kamal Khayat, Xiaojian Gao, Fazhou Wang, Zhichao Liu May 2022

For The Improvement Of Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment Using Carbon Nanotube And Graphite Nanoplatelet, Huanghuang Huang, Le Teng, Kamal Khayat, Xiaojian Gao, Fazhou Wang, Zhichao Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper investigates the influence of carbon nanotube (CNT) and graphite nanoplatelet (GNP) on the microstructure and mechanical characteristics of UHPC with steel fiber alignment. The content of CNT and GNP ranged from 0 to 0.3%, by mass of binder. Predominant fiber alignment was manipulated using a flow-induced casting method during UHPC placement. Experiment results indicated that the increase of CNT and GNP content from 0 to 0.3% led to 15%, 40%, and 50% improvement in compressive strength, flexural strength, and T150 (dissipated energy) of UHPC, respectively. Fiber alignment was shown to increase flexural strength and T150 by 30% and …


Administering Change Orders In Highway Projects, Muaz O. Ahmed, Rayan H. Assaad, Islam H. El-Adaway, Emily Echele, Kyle Govro, John Watson May 2022

Administering Change Orders In Highway Projects, Muaz O. Ahmed, Rayan H. Assaad, Islam H. El-Adaway, Emily Echele, Kyle Govro, John Watson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Change orders continue to be one of the main challenges faced by the construction industry. Despite many previous research efforts related to managing change orders in the construction industry, there is still a lack of research that investigates the contractual aspects of change orders for transportation projects. This paper tackles this knowledge gap within the context of Ohio Department of Transportation (ODOT) highway projects. To this end, the authors used an integrated research method comprised of (1) selection and analysis of ODOT case studies; (2) identification of the main change orders aspects that lead to conflicts, claims, and/or disputes in …


Understanding The Role Of Nano-Tio2 On The Toxicity Of Pb On C. Dubia Through Modeling—Is It Additive Or Synergistic?, Xuesong Liu, Jianmin Wang, Yue-Wern Huang May 2022

Understanding The Role Of Nano-Tio2 On The Toxicity Of Pb On C. Dubia Through Modeling—Is It Additive Or Synergistic?, Xuesong Liu, Jianmin Wang, Yue-Wern Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Nano-TiO2 can remarkably increase lead (Pb) toxicity in aquatic organisms. However, the mechanism of this toxicity, additive or synergistic, is not well understood. To explore this mechanism, we inspected the role of nano-TiO2 in the toxicity of Pb on Ceriodaphnia dubia (C. dubia), a model water flea species typically used for ecotoxicity studies. The effect of algae, a diet for aquatic organisms, on the effect of this binary mixture was also investigated. A two-compartment toxicokinetic (TK)-toxicodynamic (TD) modeling approach was used to quantify the Pb toxicity under these complex conditions and to develop critical parameters for understanding the …


Evolution Prediction Of Hysteresis Behavior Of Sand Under Cyclic Loading, Pingxin Xia, Longtan Shao, Wen Deng, Chao Zeng May 2022

Evolution Prediction Of Hysteresis Behavior Of Sand Under Cyclic Loading, Pingxin Xia, Longtan Shao, Wen Deng, Chao Zeng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Soil cyclic degradation is a serious issue that should be considered in engineering design and maintenance. The hysteretic response causes strength degradation and excessive settlement of soil structure in engineered and natural geosystems. Hysteresis is essentially the coupling deformation of elastic and plastic components during reloading and unloading processes. Conventional hysteretic models for sand in the elastoplastic framework rely highly on yield surface or potential surface evolution and fall short on complexity and inaccuracy. This study proposes a decoupling method to describe the hysteretic response of sand. In contrast to the conventional elastoplastic approach, this decoupling method can directly decouple …


Use Of Saturated Lightweight Sand To Improve The Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu May 2022

Use Of Saturated Lightweight Sand To Improve The Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper studied the influence of pre-saturated lightweight sand (LWS) on the mechanical and microstructural properties of UHPC cast with steel fiber alignment. The changes in hydration kinetics, porosity, nano-mechanical, and mechanical properties were studied. The LWS was used at 0–50% replacement volumes of total sand. Predominant fiber alignment was favored through a flow-induced casting method during casting of flexural prisms. Experiment results showed that the 28-d autogenous shrinkage was decreased from 450 to 275 μm/m with the LWS content increasing from 0 to 50%. The addition of 20% LWS led to maximum increases of 15%, 15%, and 20% in …