Civil Engineering Commons^™

Structural Fiber Mesh Reinforcement Of A Polymeric Heart Valve: Improving Valve Durability And Leaflet Closure Effectiveness, Peter J. Choi, Hugo Zazueta, John A. Acevedo, Philip Park

Civil Engineering Faculty Publications

Objective: Bioprosthetic valves using either porcine or bovine pericardium have been widely used for transcatheter heart valve replacements. However, producing bioprosthetic valves is not a sustainable solution. Acquiring animal tissue is often not readily available and costly and requires time-consuming modifications. Moreover, its primary tissue failure requires reoperation after roughly 15 years. The suggested replacement of porcine and bovine leaflets with biocompatible polymers appears to be an attractive alternative to bioprosthetic valves. In this study, engineered fiber-reinforced polymers were developed, which are less degenerative and offer greater hemocompatibility in relation to mechanical valves.
Methods: Polydimethylsiloxane (PDMS) polymer reduces calcification significantly …

Fitness For Service (Ffs) And Fatigue Assessment For Shell Distorted Steel Storage Tank Based On Api 579-1/Asme Ffs-1, Wira Herucakra Sr. Structure Engineer, Luh Putri Adnyani, Ic Farid Hadi Prasetyo, Alviani Rahma Rizkhita

Journal of Materials Exploration and Findings

A shell distortion was occurred due to incorrect in the welding procedure during construction of a new built above ground steel storage tank. The assessment level 1 then performed referred to original construction code of API Standard 650 was performed, the roundness data of tank plate was obtained through to laser scanning survey, and the result on assessment level 1 known that the minimum radius of measured point is exceeding the radius tolerance. This unacceptable condition of assessment level 1 requires to be performed the higher level of assessment. A fitness for service assessment level 3 for tank 1000 KL …

Development Of 485 Mpa Class High Strength Low Alloy Steel For Power Plant Infrastructures, Agung Baskoro, Rini Riastuti

Journal of Materials Exploration and Findings

Currently, Indonesia is progressing to build 35,000 MW of power plants, which will increase the demand for materials, especially steel. One of these power plants is fossil fuel-based, which generates not only electricity but also flue gas containing sulfur that may cause corrosion to power plant infrastructure such as chimney or boiler areas. In addition, apart from being resistant to corrosion in sulfuric and hydrochloric acid conditions, the steel used in power plant infrastructure must also have good strength, toughness, and weldability. Therefore, the present paper describes about steel development for power plant applications that has not only corrosion resistance …

Optimizing Flash Flood Prediction In Arid And Semi-Arid Regions: A Comparative Evaluation Of Infiltration Models And Parameter Estimation Guidance Across Spatial Scales, Sara Rassa

Civil Engineering ETDs

This study improves flash flood prediction by analyzing the vital role of infiltration models in hydrologic modeling, especially for areas with scarce data. It offers new parameter estimation guidance for three infiltration models—initial-constant (IC), linear-constant (LC), and Green-Ampt (GA)—based on plot-scale rainfall simulations. The research emphasizes the impact of soil texture, moisture, and crust on model parameters. A comparative analysis of four models (curve-number, IC, GA, and LC) using data from Arizona's Walnut Gulch Experimental Watershed under different calibration scenarios shows the GA model's superiority in certain conditions, though it faces issues of equifinality in unconstrained calibrations. Meanwhile, the simpler …

Flexural Investigation And Retrofit Of Aashto Type Iii Prestressed Girder-Deck System With Strand Bond Damage, Haoran Ni

Dissertations - ALL

Prestressed concrete (PC) bridge girders play an important role in highway bridges because of their embedded prestressing strands and low cost. They can provide adequate flexural strength depending on the integrity of the concrete-strand bond. However, highway bridges near industrial facilities are often subjected to heavy trucks. Under frequent overloads, the large deflections of bridge girders may induce deterioration of the bond between the strands and concrete at critical sections during bending, resulting in debonding of the strands in the most critical section region, over the span length. This study describes an in-depth analysis of the flexural strength of a …

Multi-Scale Analysis Of The Structure-Mechanics Relationship Of Mycelium-Based Bio-Composites, Libin Yang

Dissertations - ALL

The construction industry faces significant challenges due to the environmental impact of traditional materials like steel and concrete, whose production is energy-intensive and contributes to environmental pollution. This issue is exacerbated by the growing global demand for construction materials, driven by an increasing population. Concurrently, the agricultural and wood industrial sectors produce vast byproducts, such as straw, husk, coir, sawdust, and wood chips. They are often considered as wastes and disposed of through methods like burning. Such a reckless treatment releases greenhouse gases that further lead to environmental degradation. Mycelium, the vegetative part of fungi, presents a natural, promising solution …

Investigating The Effects Of Suspended Algal Content, Dissolved Oxygen, And Temperature On A High-Frequency Acoustic Attenuation System In A Controlled Laboratory Environment, Noah Watson

Honors Theses

The Single Frequency Acoustic Attenuation System (SFAAS) has been developed at the National Center for Physical Acoustics (NCPA). This system uses acoustic methods to monitor fine suspended sediment concentration in streams. Site-specific calibrations are necessary for this system, and previous research has indicated that algal concentration or dissolved oxygen concentration of water may affect collected data. Temperature, dissolved oxygen concentration, and fluorescence, used as a proxy for algal concentration, were monitored during this system’s use, and calibrations were derived to account for the effect of each of these variables on acoustic measurements. It has been shown that temperature has a …

The Use Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Properties Of Green Roof Media And Granular Soils, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr.

Publications and Research

This study investigates using repurposed whole textiles to modify the mechanical and hydrogeological properties of lightweight Green Roof media and granular pavement soils.

Green Roof Media Green roofs aim to bring the advantages of suburban agriculture to urban environments while improving energy efficiency and enhancing stormwater management in public, commercial, and residential buildings. Previous studies by City Tech undergraduate research assistants demonstrated significant modification in hydrogeological properties when incorporating textile fabric up to 3% textile by weight (%Tex) at an aspect ratio of 1:1. The effects of mixing repurposed whole textile fiber with Green Roof media is evaluated with regards …

Effect Of Waste Covid-19 Masks On Compaction Characteristics Of Silty-Clay Soil, Sydney K. Lawson

Honors College Theses

The present study aims to explore the effect of adding shredded waste Covid-19 masks to silty-clay soil on the soil’s compaction characteristics for beneficial use in embankment, the subgrade of roadways, or backfill. This was accomplished by using two different types of masks: blue surgical masks and KN95 masks. Both mask types were hand shredded into half-inch sections using safety-scissors. The maximum dry density (MDD) and optimum moisture content (OMC) are the two most important compaction characteristics, and they were determined by the Standard Proctor Compaction Test (ASTM D698 / AASHTO T99). The change of both the MDD and OMC …

Quality Assurance And Quality Control For Reinforced Concrete Inspections, Calvin O. Walters Jr.

Publications and Research

Ensuring the safety and longevity of structures is paramount in concrete construction projects. Cases like the Big Dig ceiling collapse, which occurred on July 10, 2006, when a concrete ceiling panel measuring 20' x 40' and debris weighing 26 short tons (52,000 lb) fell within Boston's Fort Point Channel Tunnel, underscore this importance (Wald, M. L., 2007). Quality Assurance (QA) and Quality Control (QC) are crucial in mitigating such risks. QA ensures that materials and methods meet predetermined performance, design, and reliability standards specified in contracts and customer arrangements. On the other hand, QC is a strategic process businesses use …

Environmental Drivers Impact The Accumulation And Diversity Of Antibiotic Resistance In Green Stormwater Infrastructure, Kassidy N. O'Malley, Patrick J. Mcnamara, Christopher Marshall, Emily Lou Lamartina, Thuy Duyen Lam, Numair Ali, Walter M. Mcdonald

Civil and Environmental Engineering Faculty Research and Publications

Antibiotic resistance poses an urgent public health concern, with the environment playing a crucial role in the development and dissemination of resistant bacteria. There is a growing body of research indicating that stormwater is a significant source and transport vector of resistance elements. This research sought to characterize the role of green stormwater infrastructure (GSI), designed for stormwater infiltration, in accumulating and propagating antibiotic resistance in the urban water cycle. Sampling included 24 full-scale GSI systems representing three distinct types of GSI - bioswales, bioretention cells, and constructed wetlands. The results indicated that GSI soils accumulate antibiotic resistance genes (ARGs) …

Creating A Bio-Based Circular Economy From Louisiana Sugarcane Byproducts, G. Aita, D. Bhatnagar, G. O. Bruni, M. Deliberto, G. Eggleston, A. Finger, K. Gravois, M. Isied, W. Judice, K. T. Kasson, I. M. Lima, J. L. Purswell, Mena I. Souliman, E. Terrell, B. S. Tubana, H. L. Waguespack Jr., J. J. Wang, P. M. White Jr.

Civil Engineering Faculty Publications and Presentations

Sugarcane (Saccharum officinarum) is Louisiana's number one row crop. Growing and processing sugarcane produces significant amounts of byproducts, including bagasse, crop residue, molasses, filter-press mud, and boiler fly ash. These products represent an important opportunity to generate value-added and specialty products and enhance sugarcane's sustainability by facilitating a circular economy, where agricultural by-products are reused instead of disposing them (linear economy), in order to reduce resource use and energy demand. Examples of value-added products range from biochar, construction materials, animal feed, biofuels, nanoparticles, and fertilizer. Paramount to the success of the bio-based circular economy is creating useful products that are …

Comparison Of Embodied Carbon Footprint Of A Mass Timber Building Structure With A Steel Equivalent, Mahboobeh Hemmati, Tahar Messadi, Hongmei Gu, Jacob Seddelmeyer, Moein Hemmati

Architecture Faculty Publications and Presentations

The main purpose of this study is to quantify and compare the embodied carbon (EC) from the materials used or designed to build the Adohi Hall, a residence building located on the University of Arkansas campus in Fayetteville, AR. It has been constructed as a mass timber structure. It is compared to the same building design with a steel frame for this study. Based on the defined goal and scope of the project, all materials used in the building structure are compared for their global warming potential (GWP) impact by applying a life cycle assessment (LCA) using a cradle-to-construction site …

Micro-Mechanical Characterization Of Uhpc Stiffness Mechanisms: Towards A Better Understanding Of Concrete Elastic Modulus, Charissa N. Puttbach

Graduate Theses and Dissertations

Current design code equations for estimating the elastic modulus of specialty concretes like ultra-high performance concrete are not all suitable. Developing empirical curves from exhaustive experimental testing is challenging for concretes that may have high levels of cement replacement with mineral admixtures and fibers at varying volume contents. As such, an alternative approach is taken that seeks to understand the constituent microscale stiffness mechanisms and relate the results to the macroscale. Micropillars are fabricated on several cement paste phases using a focused ion beam. A modified pico-indenter is used to determine the linear and non-linear behavior under micro-compression loading. Micropillar …

Providing A Statistical Analysis Framework For Agencies To Analyze The Parameters Influencing The Rutting And Cracking Performance Of Asphalt Mixtures, Mohammad Tahir Ansari

Graduate Theses and Dissertations

Many state agencies recognize that their current asphalt mixtures are susceptible to cracking and poor durability. Some agencies are adjusting their mix design procedures to increase the asphalt binder content, while others are moving toward a balanced mix design (BMD) to try and address both cracking and rutting. However, there is uncertainty on what asphalt mixture properties can impact cracking and rutting. This research explores the IDEAL-CT and APA data from two years of mix designs collected by ARDOT. To understand which asphalt mixture properties impact cracking and rutting in the field, Pearson correlation (PCM), Spearman rank correlation (SCM) and …

Proctor And Harvard Miniature Compaction Energy Comparison, Julia Loshelder

Graduate Theses and Dissertations

Compaction with the Harvard Miniature Compaction Apparatus (HMCA) was investigated to develop a method that can be used in place of typical Proctor compaction. Advantages for compaction with the HMCA include the need for less soil for testing and less preparation time. To investigate the potential for HMCA as a replacement, soil specimens were compacted with both the Proctor and HMCA methodologies at equivalent energies. For this testing, the testing included modified energy (56,250 ft-lbf/ft³ [2693 kN-m/m³]), standard energy (12,375 ft-lbf/ft³ [593 kN-m/m³]), and reduced energy (6188 ft-lbf/ft³ [296 kN-m/m³]). Because …

Cyclic Testing Of A Skewed Special Moment Frame Rbs Connection Having A Composite Concrete Slab, Adam Neil Kirchner

Graduate Theses and Dissertations

Special moment frames (SMFs) having reduced beam section (RBS) connections are commonly used in high seismic areas as they resist lateral forces while preserving critical welded connection regions. RBS SMFs provide brace-free, unobstructed frame options which can be favorable for architectural purposes. However, when building designs require non-rectangular framing, laterally skewed connections may be needed. Current design provisions for SMF connections provide only limited commentary on such non-orthogonal connections as limited research exists documenting skewed frame behavior. This study experimentally evaluates the cyclic behavior of a full-scale double-sided skewed SMF RBS specimen having a composite concrete slab. During the imposed …

Use Of Bcsa Cement In Soil-Cement Mixtures As A Rapid Flood Repair Technique, Mariel Mayori Rivero

Graduate Theses and Dissertations

The research discusses the vulnerable condition of hydraulic structures, specially dams and levees located in the United States, structures that are often times made of earthfill material and that have been greatly impacted by recent flood events. The need for a rapid setting material for active flood fighting efforts is inarguable, in order to mitigate collateral expenses caused by the often long closure times when repair is taking place, especially when dewatering is necessary. Therefore, this research tested different proportions of cement in soil-cement mixtures at varying moisture contents with the interest of evaluating the performance of the soil-cement when …

Investigating Rural Traffic Dynamics: A Traffic Study On E 2nd Street Intersection’S Behavior And Safety, Ma Anjelika Rose T. Pineda

2024 Spring Honors Capstone Projects - Archive

Traffic studies guide engineers in designing road networks to ensure smooth traffic flow and public safety. Such studies assess the need for traffic control devices to manage vehicle flow safely and efficiently. This is crucial at intersections which pose high risks of collision and congestion. A traffic analysis at the intersection of Island Grove and E 2nd Street on the FM-4 roadway in Cleburne, TX was conducted to evaluate the sufficiency of the current traffic control device. TxDOT warrants and standards and a field study were utilized and performed to justify the substitution for a traffic signal at the intersection. …

Effect Of Swirl Ratio On Simulated Vortech Chamber Vortex Parameters, Samuel Kolar

Civil Engineering Undergraduate Honors Theses

A numerical simulator can use computational fluid dynamics (CFD) to model an experimental tornado-simulating chamber at Texas Tech University (known as VorTECH). Previous studies evaluating this particular CFD model have produced results that compare the touchdown swirl ratio (S_TD), core radius (r_c), maximum tangential velocity at touchdown (V_tmax @ S_TD), and height of the maximum tangential velocity (z_c) reasonably well with experimental data from the VorTECH facility. The effects of swirl ratio beyond S_TD on important vortex parameters including r_c, V_tmax, z …