Civil Engineering Commons^™

Reuse Of Calcium Carbonate (Caco3) Recovered From Discarded Carpets As Filler In Fiber-Reinforced Polymer (Frp) Composites, Roshan Devkota

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over four billion pounds of carpet are discarded annually in the United States, making carpet waste a significant environmental concern. Calcium carbonate (CaCo₃) constitutes up to 45% of the mass of most synthetic carpets. Reusing this CaCo₃ as a filler in the rapidly growing fiber-reinforced polymer (FRP) industry, which is projected to reach USD 10.38 billion, presents a low-cost, practical approach to developing a market-based solution to post-consumer carpet waste.

This study investigates the reuse of CaCo₃ recovered from discarded carpet backing as a filler in FRP composites, focusing on its mechanical viability in comparison to virgin CaCo₃. The methodology …

Anti-Corrosion Performance Of Magnesium Potassium Phosphate Cement Coating On Steel Reinforcement: The Effect Of Boric Acid, Fan Zhang, Jihui Qin, Kangyi Cai, John J. Myers, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It has recently been found that magnesium potassium phosphate cement (MKPC) paste coating applied on the surface of steel reinforcement can effectively retard the onset of corrosion and suppress corrosion reactions. However, the fast-setting nature of MKPC—which is a merit in repair—can be problematic in a practical engineering process of coating the steel reinforcement with MKPC paste. To address this problem, boric acid (H₃BO₃) was added as a retarder in an MKPC formulation to prolong the setting time. This work investigated the impact of boric acid (at 5% by weight of MgO) on the anti-corrosion performance …

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …

Proportioning And Performance Of Ultra-High Performance Concrete (Uhpc) For High Friction Surface Treatment (Hfst) On Pavement And Bridge Decks, Adam R. Biehl

All Theses

High Friction Surface Treatment (HFST) is a roadway remediation technique used to improve pavement’s coefficient of friction, to enhance roadway safety. The application of HFSTs has repeatedly demonstrated the ability to significantly reduce crashes in both wet and dry conditions. Typically, epoxy-resins and calcined bauxite aggregate are used in HFST treatment. However, the high material costs and scarcity of calcined bauxite render this form of HFST an expensive and limited option for roadway rehabilitation. Therefore, the identification of alternative binders and HFST aggregates is needed for broad scale implementation. One potential alternative binder is Ultra-High-Performance Concrete (UHPC), a specialty cementitious …

Performance Evaluation Of Asphalt Binder Modified With Recycled Plastics, Abeeb G. Oyelere

Graduate Theses and Dissertations (2019 - present)

The surge in the production of plastic waste has become a pressing global environmental issue. To address this, repurposing plastic waste to modify asphalt binders in asphalt pavement is being explored This study investigates the potential of recycled high-density polyethylene (rHDPE) and recycled polypropylene (rPP) as asphalt binder modifies to improve pavement performance and sustainability while mitigating plastic waste's adverse environmental impacts. Laboratory investigations were conducted to assess the rheological performances as well as the compatibility of rHDPE and rPP-modified asphalt. Additionally, the impact of aging and mixing temperature on rheological performance was investigated. Experimental results indicated that adding these …

An In – Depth Analysis Of Natural Fibers :A Comprehensive Review Of Properties And Performance Characteristics, Abbas Chour, Jamal Khatib

BAU Journal - Science and Technology

The purpose of this research is to investigate the usage of natural fibers in plant-based natural fiber-reinforced cement-based composites for sustainable construction materials. It summarizes research on various fiber kinds, their properties, and their impact on cement-based products, with a focus on renewable possibilities such as flax, jute, ramie, hemp, cotton, sisal, and kenaf. Due to their hydrophilic nature, plant fibers and polymers present compatibility concerns and moisture damage when combined. The paper examines ways for improving durability, such as physical and chemical treatments to improve aging resistance, optimizing binder components, and modifying curing regimens to reduce alkalinity in the …

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 …

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 …

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 …

Smart Manufacturing Of Cement: From Lab-Scale Simulation And Testing To Industry-Scale Deployment., Juan David Tabares Tamayo

Electronic Theses and Dissertations

Cement kilns are controlled by experienced process operators who follow experience-based industry guidelines using data collected and fundamental knowledge. The manufacturing process, which is equipped with sensors and equipment, transfers data/information to the operators to aid standardized decision-making operations. In contrast, companies have used such data to develop and implement digital solutions for predictive control systems; in effect, FLSmidth and Rockwell Automation. However, despite the availability of automated control systems and investigation in automation for process monitoring and optimization, opportunities to radically optimize cement manufacturing are still abundant and in need of implementation. Therefore, this research developed simulation models and …

Quasi-Static And Impact Load Response Of Bfrp-Reinforced Concrete Beams And Post-Terrorist-Attack Sub-Assemblages, José Luis Carrasquillo

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a theoretical and experimental study of Basalt Fiber Reinforced Polymer (BFRP) reinforced concrete beams and post-terrorist-attack subassemblages subjected to either quasi-static or impact load. Both BFRP reinforcement as well as BFRP fabric are used in this investigation. The sub-assemblage consists of an otherwise two-span beam converted to a fixed-end single-span one owing to the loss of a middle column blasted off during the terrorist attack. The simply supported beams are subjected to a midspan quasistatic or an impact load. However, each sub-assemblage is subjected to a quasi-static load up to collapse to simulate the …

Thermo-Elasto-Plastic Stability Of Biaxially Loaded Hollow Rectangular Section Steel Beam-Columns With Applied Torsion, George Adomako Kumi

Civil & Environmental Engineering Theses & Dissertations

Presented herein is an experimental and theoretical study of biaxially loaded hollow rectangular section steel beam-columns with applied torsion at elevated temperatures. The theoretical analysis is based on a system of simultaneous materially nonlinear differential equations of equilibrium for which an iterative semi-analytic solution approach is formulated. Although the primary goal of this research is to study the influence of elevated temperatures on the steel member with the complex loading, rigorous analysis is also conducted of the member at ambient temperature for comparison. The experimental part of the study involves conducting tests on the members at both ambient and high …

Thermal Insulation And Fire Protection Plaster For Frp System Incorporating Aerogel Nanoparticles And Phyllosilicates, Athnasious Ghaly

Theses and Dissertations

For more than two decades, new innovative materials have been introduced to the market such as nano materials that can be utilized for their high performance in different aspects of the construction industry. Structural repair and strengthening is one of the most demanding fields in the construction industry for innovative and high-performance materials due to its specialty. Time, quality, economy, and sustainability are the main factors that control this field, and for that, new systems keep being introduced to the market to reduce the time of repair and enhance its efficiency. Fiber Reinforced Polymers (FRP) Systems are the most advanced …

Mechanical And Electromagnetic Properties Of Incorporating Graphene Oxide In Cementitious Mixtures, Cherif Khalil

Theses and Dissertations

This multidisciplinary study aimed at investigating the impact of incorporating graphene oxide (GO) on the mechanical properties and electromagnetic (EM) shielding effectiveness of cementitious mixtures, as well as critically examining the mechanism with which GO affects their microstructure properties. Analysis of the literature review showed that there are discrepancies in reporting the impact of GO on the mortar mix. Consequently, this study focuses on exploring the cause for such discrepancies and identifies three main factors which are thoroughly investigated. The factors were the different sonication energies applied to the GO (Shear Mixing, 1.5 kJ/ml, 3 kJ/ml and 6 kJ/ml), the …

Research On Orthogonal Test Of Mgo-Fiber Cement Soil′S Deformation Modulus, Hu Qizhi, Yu Yang, Ma Qiang, Zhuang Xinshan

Journal of China & Foreign Highway

Appropriate amounts of MgO and fiber can improve the compressive strength of cement soil. In order to further study the mechanical properties of MGO-fiber cement soil, Minitab software was used to design an orthogonal test method, and sensitivity analysis and influence analysis were carried out. The change rules of deformation modulus of MgO content, fiber content, and fiber length were studied at three different levels. The regression equations of MgO content, fiber content, and fiber length with cement soil deformation modulus were obtained by using Matlab software to process the test data. The sample was tested by scanning electron microscope …

Experimental Study On Performance Of Cast Asphalt Mixture Basedon Dry Modification, Wang Ming, Li Bo, Bao Guangzhi, Hu Deyong

Journal of China & Foreign Highway

Cast asphalt mixture is the most widely used material for the pavement of long-span steel bridge decks, and the special asphalt binder cannot be produced and used in small batches. The wet modification process is obviously not suitable for the production of the cast asphalt mixture during the operation and maintenance period. In this paper, according to the requirements of cast asphalt mixture and its binder, combined with the requirements of the dry modification process, the developed direct injection modifier was employed to conduct the mix design of cast asphalt mixture and tests of the fluidity, penetration and increment, low-temperature …

Effect Of Admixtures On Rapid Hardening, Self-Consolidating Concrete, Haley Johnson

Theses and Dissertations--Civil Engineering

Self-consolidating, rapid-hardening concrete is a sought-after product in the market now, however the effects of admixtures on fresh and hardened concrete rheology are still uncertain. This study aims to create a self-consolidating concrete (SCC) using calcium sulfoaluminate (CSA) cement for its rapid-hardening properties, and tests two set time retarders and two viscosity-modifying admixtures (VMAs) to determine how they affect the properties of concrete. The properties studied in this thesis are workability, viscosity, set times, air content, compressive strength, and freeze-thaw resistance of self-consolidating concrete. It was found that tartaric acid creates a very workable SCC with consistent results regardless of …

Thermal Alteration Of The Mineralogy Of Calcium Sulfoaluminate Cements: Implications For The Performance Of Rapid Repair Materials, Jillian Cavellier

Theses and Dissertations--Earth and Environmental Sciences

Calcium sulfoaluminate (CSA) was developed in part to lessen the environmental impact of cementitious materials compared to traditional Portland cements. CSA was first put into production in the 1970s and has been undergoing various performance testing to investigate its durability. Yet to be evaluated is CSA’s response to a rapid, high temperature event. In this study, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectrometry and scanning electron microscope imaging were used to analyze alterations in the mineralogy due to such an event. As found in previous studies, after ~125°C, ettringite has been completely dehydrated. Ettringite decomposes into bassanite and calcium …

Degree Of Dispersion/Exfoliation And Surface Functionalization Of 1d And 2d Carbon Nanostructured Materials: Interface Interactions And Effects On Mechanical Properties, Michail Margas

Material Science and Engineering Dissertations - Archive

The development of advanced cementitious nanocomposites relies heavily on understanding the interfacial interactions between carbon-based nanomaterials and the cement matrix, which significantly influence the material’s performance. The goal of this dissertation is to investigate the effect of dispersion/exfoliation and surface functionalization of 1D multiwall carbon nanotubes (MWCNTs), carbon nanofibers (CNFs), and 2D graphene nanoplatelets (GNPs) in aqueous suspensions on the interface interactions of nanoengineered cementitious composites. The first objective of this dissertation is to quantitatively evaluate the degree of nanomaterial dispersion for MWCNT and CNF suspensions, in a converging manner for cement-based materials applications using spectroscopic techniques, such as UV-vis …

Isolation And Characterization Of Caffeine-Degrading Bacteria From Coffee Plantation Areas In Malaysia, Elvina Clarie Dullah, Mohd Fazli Farida Asras

Makara Journal of Technology

Decaffeination by microbial degradation is currently the most optimal and low-cost approach, involving only microbial cells and/or their enzymes. The bacterium was characterized using a series of biochemical tests. Positive results were obtained from carbohydrate fermentation, citrate utilization, and catalase tests, while negative results were obtained from Voges-Proskauer (VP) and indole tests. Three different caffeine concentrations of 0.25%, 0.4%, and 2% were tested and measured through Gas Chromatography-Mass Spectrophotometry (GC-MS) analysis. The highest caffeine reduction (89.25%) was found when 0.25% caffeine was used in the media. Only a small amount of caffeine was reduced to 0.4% and 2%, with 34.78% …

Optimization Of The Building Envelope And Roof Shading To Reduce The Energy Consumption Of College Low-Rise Buildings In Indonesia, Nasruddin Nasruddin, Azimil Gani Alam, Mohammad Imroz Sohel

Makara Journal of Technology

Energy consumption in buildings is a crucial concern globally, prompting researchers to explore innovative solutions to mitigate its impact. This study investigates the optimization of building envelopes and roof shading systems of existing buildings in Indonesia to realize notable energy savings. Multiple scenarios were explored, with modifications to building envelopes and roof shading, highlighting the overall thermal transfer value as a key parameter. Using EnergyPlus simulations, the efficacy of natural ventilation in corridors and roof shading modifications was assessed in reducing energy consumption. The findings revealed that renovating existing buildings by optimization of the building envelope and roof shading by …

Modeling Of Asphalt Concrete For Cross-Anisotropic Visco-Elasticity And Heterogeneity, Zafrul Hakim Khan

Civil Engineering ETDs

Asphalt Concrete (AC) is a cross-anisotropic viscoelastic material. This study has developed a methodology to backcalculate the cross-anisotropic properties of the AC layer from the Falling Weight Deflectometer (FWD) sensor and pavement response data from embedded sensors inside a pavement section. This study has also developed a two-way coupled Multiscale Finite Element Model (MsFEM) with Phase Field Fracture (PFF) to study the microstructural heterogeneity and damage of the AC layer based on the actual field loadings. A Finite Difference Time Domain (FDTD) and Machine learning-based backcalculation algorithm were developed to determine the layer thickness and dielectric constant from air-coupled Ground …

Evaluation Of The Long-Term Performance Of Ogfc In South Carolina, Rishiraj Brahmbhatt

All Theses

Since the 1970s, South Carolina has employed open graded friction courses (OGFC) on high-speed asphalt roadways to enhance wet weather safety. While these mixes have indeed enhanced safety, they still grapple with durability issues, particularly concerning raveling. This research aimed to assess the prolonged performance of OGFC pavements in South Carolina, with a specific emphasis on isolated raveling occurrences. In 2012, the South Carolina Department of Transportation (SCDOT), constructed the first Warm Mix OGFC test section in South Carolina on I-20 Eastbound in Kershaw County, spanning 3.9 miles, using the Evotherm additive and excluding fibers. Following the success of this …

Structural Performance And Resiliency Of Reinforced Concrete Bridge Pier Columns, Multi-Column Piers, And Bridge Systems Subjected To Multiple Hazards – Fire, Collision, And Air Blast, Qusai Abdulkarim Alomari

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Given their close proximity to traffic and improper employment of protective systems, bridges and bridge piers are vulnerable to multi-hazard events triggered by vehicle collisions coupled with correlated and cascading events, such as explosions and fires. Despite recent catastrophic incidents that have highlighted the profound consequences of these extreme demands, including substantial damage, adverse economic impact, and loss of life, there has been a notable lack of research investigating the performance of bridges and bridge structural components under the aforementioned multi-hazards. Furthermore, current bridge design codes do not address these events assuming that, after these destructive events, replacement of the …

Study On Performance And Dynamic Response Of Composite Stress Absorber Layer, Yang Sanqiang, Li Pengfei, Liu Lu, Cao Zilong

Journal of China & Foreign Highway

In order to compare the performance difference among the composite stress absorption layer, SBS stress absorption layer, and glass grille stress absorption layer, the dynamic response law of the composite stress absorption layer was explored. In this paper, based on the composite stress absorption layer composed of glass grille + rubber-modified asphalt gravel sealing layer, the UTM-25 test system was employed to carry out inter-layer shear, inter-layer tension, low temperature bending, and four-point fatigue test. By laying test sections and sensors, strain information of the stress absorption layer under different conditions was collected. It was found that the bonding force …

Durability Of Cfrp/Steel Bond In Natural Weather, Mastour Alsulami

USF Tampa Graduate Theses and Dissertations

Fiber reinforced polymers (FRP) are increasingly being used for infrastructurestrengthening and repair of steel structures. Though there have been several durability studies, exposures used are not representative of outdoor service conditions. Fewer studies have explored the effect of changing outdoor conditions typical in infrastructure use. The goal of the research is addressing this gap by evaluating the performance of commercially available CFRP systems under natural weather characteristic of hot, humid tropical conditions mainly and cold weather secondary in three different locations.

Thirty CFRP/steel joint specimens were prepared in laboratory conditions and exposed to ambient temperature on the Engineering building roofs …

Challenges In Optimization For The Performance On Sustainability Dimensions In Reverse Logistics Social Responsibility, Sumarsono Sudarto, Katsuhiko Takahashi, Mochammad Dewo

Makara Journal of Technology

Reverse logistics social responsibility is preferred as the most acceptable solution for addressing the challenges in stakeholders’ debate regarding social responsibility in supply chains because it involves as many actors as possible in the supply chain to perform social responsibility to achieve sustainability. This paper explores the challenges in achieving optimal policies in sustainability dimensions for collection and recycling facilities in reverse logistics. Sustainability dimensions include economic, environmental, and social aspects. The reverse logistics is modeled on System Dynamics, and a simplified statistical analysis using a contour chart is employed in numerical experiments. Results show a narrow area of optimal …

Mechanical And Durability Properties Of Fly Ash Geopolymer Concrete – A Review, Ali Shebli, Jamal Khatib, Adel Elkordi

BAU Journal - Science and Technology

Geopolymers have emerged as a promising alternative for Ordinary portland cement (OPC) in construction industry, due to their potential to minimize the emissions of carbon dioxide (CO₂) and improve the efficiency of waste recycling. This paper aims to study the fresh and hardened properties of fly ash geopolymer concrete (GPC), as well as to review the raw materials used in the production of geopolymers. Several factors impact the mechanical and durability properties of fly ash GPC, including the specific type of fly ash utilized, the curing temperature, the alkaline activator (AA) concentration, and the type of AA used. …

Integrating Steel Slag Aggregates Into Asphalt Paving By Harmonizing Availability, Quality, Economics, And The Environment, Timothy R. Murphy

Theses and Dissertations

This thesis provides guidance on how to balance matters related to the environmental stewardship, market sources, origin and uses, material properties, performance, and economic impact of using slag materials in pavements. The literature on this topic provides numerous references on the use of slag materials for specific applications, and this thesis aims to make use of those references along with other data from the author to describe slag materials from a holistic perspective and provide some suggestions for balancing several factors that impact optimal use of this resource within pavement structures. Discussion is given to the increased importance of recycling …

Review: Inelastic Constitutive Modeling: Polycrystalline Materials, Mirza Baig, Josiah Owusu-Danquah, Anne A. Campbell, Stephen F. Duffy Phd, Pe

Civil and Environmental Engineering Faculty Publications

This article provides a literature review that details the development of inelastic constitutive modeling as it relates to polycrystalline materials. This review distinguishes between inelastic constitutive models that account for nonlinear behavior at the microstructural level, time-independent classic plasticity models, and time-dependent unified models. Particular emphasis is placed on understanding the underlying theoretical framework for unified viscoplasticity models where creep and classical plasticity behavior are considered the result of applied boundary conditions instead of separable rates representing distinct physical mechanisms. This article establishes a clear understanding of the advantages of the unified approach to improve material modeling. This review also …