Civil and Environmental Engineering Commons^™

Additive Manufacturing And Performance Of Architectured Cement-Based Materials, Mohamadreza Moini, Jan Olek, Jeffrey P. Youngblood, Bryan Magee, Pablo D. Zavattieri

Lyles School of Civil Engineering Faculty Publications

There is an increasing interest in hierarchical design and Additive Manufacturing (AM)of cement-based materials. However, the brittle behavior of these materials and the presence of interfaces from the additive manufacturing process represent the current major challenges. Our work focuses on harnessing the heterogeneous interfaces by employing clever designs from bio-inspired Bouligand architectured materials. In this paper, we aim to demonstrate some key mechanisms that can allow brittle hardened cement-based materials to gain flaw-tolerant properties. Mechanisms such as cracktwisting at the interfaces have been previously observed in naturally-occurring orsynthetic composite Bouligand architectures. In this paper, a heterogeneous interface with porous characteristics …

Evaluation Of Traffic Incident Timeline To Quantify The Performance Of Incident Management Strategies, Henrick Joseph Haule

UNF Graduate Theses and Dissertations

Transportation agencies are introducing new strategies and techniques that will improve traffic incident management. Apart from other indicators, agencies measure the performance of the strategies by evaluating the incidents timeline. An effective strategy has to reduce the length of the incident timeline. An incident timeline comprises various stages in the incident management procedure, starting when the incident was detected, and ending when there is the recovery of normal traffic conditions. This thesis addresses three issues that are related to the traffic incident timeline and the incident management strategies.

First, co-location of responding agencies has not been investigated as other incident …

The Role Of Wave Self-Similarity In Nearshore Wave Spectra, Morgan M. Smith

UNF Graduate Theses and Dissertations

Nonlinear wave-wave interactions and wave breaking contribute to nearshore wave energy dissipation. These factors can be analyzed by the principles of wave self-similarity. The equilibrium range can be shown in wind-driven wave spectra that exist in the form ( ) and However, the appropriate methods used to determine this loss of energy are controversial. This study examines an approach that reinvestigates the self-similarity principles. Wave spectra with lower peak periods are dominated by nonlinear wave-wave interactions which produce a scaling in shallow water. This thesis investigates the relative role of spectral similarity in different conditions in the nearshore region of …

Soil Improvement Using Microbial Induced Calcite Precipitation And Surfactant Induced Soil Strengthening, Matthew P. Davies

UNF Graduate Theses and Dissertations

Microbially induced calcite precipitation (MICP) has been used for a number of years as a technique for the improvement of various geological materials. MICP has been used in a limited capacity in organic rich soils with varying degrees of success. Investigators hypothesized that microbially-induced cementation could be improved in organic soils by using a surfactant. Varying amounts of Sodium Dodecyl Sulfate (SDS) were added to soils of varying organic content and a mixing procedure was used to treat these soils via MICP. Treated specimens were tested for unconfined compressive strength (UCS). Results appeared to show direct relationships between SDS content …

Shear Performance And Behavior Of Long Carbon Fiber Reinforced Concrete, Benjamin Paul Gliha

Doctoral Dissertations

”In this study, a laboratory testing program was developed to investigate the shear performance of fiber reinforced concrete beams. Long carbon fibers, to be included with a traditional fresh concrete mix, were developed and their shear performance was evaluated and compared to the performance and behavior of unreinforced concrete, traditionally reinforced concrete, and fiber reinforced concrete (FRC) with other fiber types.

The experimental program consisted of 30 large-scale beams tested for shear performance under monotonic loading. In addition to the large-scale beams, small-scale specimens were constructed of the same materials to correlate large-scale performances to ASTM C1609 testing and to …

Terahertz Imaging Of Thin Film Layers With Matched Field Processing, Scott Schecklman, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

Terahertz (THz) time of flight (TOF) tomography systems offer a new measurement modality for non-destructive evaluation (NDE) of the subsurface layers of protective coatings and/or laminated composite materials for industrial, security and biomedical applications. However, for thin film samples, the time-of-flight within a layer is less than the duration of the THz pulse and consequently there is insufficient range resolution for NDE of the sample under test. In this paper, matched field processing (MFP) techniques are applied to thickness estimation in THz TOF tomography applications, and these methods are demonstrated by using measured THz spectra to estimate the the thicknesses …

Impact Of Critical Path Method (Cpm) Of Scheduling On On-Time Completion Of Transportation Projects, Fahim Ahmed

Theses and Dissertations

This study addresses the effectiveness of Critical Path Method (CPM) scheduling on project delivery. Specifically, the on-time completion of projects with and without a CPM schedule is explored. The paper uses data from 2,097 South Carolina transportation projects let after February 2008 and substantially completed by August 2015. The delay analysis uses the original contract completion date as well as the completion date adjusted by change orders. Chi-Squared tests are used to examine the relationship between CPM scheduled projects and delayed projects, and t-tests are used to compare the mean delay (in days) between CPM scheduled and unscheduled projects. The …

Evaluation Of Sonocatalytic Degradation Of Ibuprofen And Sulfamethoxazole In The Presence Of Various Catalysts, Yasir Alhamadani

Theses and Dissertations

Over the last two decades, large quantities of products, such as medicines, disinfectants, and personal care products, have been released into surface waters and wastewater treatment facilities by the pharmaceutical and chemical industries which have come to the attention of scientists with regard to their impacts on life in lakes, rivers, and groundwater. Among various types of treatment processes, ultrasonic (US) treatment process was used in this study to investigate the effect catalysts and removal of selected pharmaceutical’s (PhACs) compounds (ibuprofen (IBP) and sulfamethoxazole (SMX)). Carbon nanomaterials (CNMs) have become candidates for numerous applications in nanocomposites, microelectric devices, sensors, energy …

Analysis On The Influence Factors Of Accident Severity: Evidence From Urban River-Crossing Tunnels In Shanghai Of China, Wan He, Zhuoye Zhang, Linjun Lu, Zhenyu Wang

CUTR Faculty Journal Publications

To analyze various factors influencing the accident severity of urban river-crossing tunnels, 12 influence factors were selected according to the three traffic elements of vehicle, road, and environment, including accident-involved vehicle type, tunnel length, tunnel speed limit, accident occurrence time, and weather. These factors were based on the historical data of 14 urban river-crossing tunnels in Shanghai. A binary logistic regression model was also utilized to identify significant influence factors and analyze the influence degrees of their accident severity. Significance analysis reveals that accident occurrence place, accident-involved vehicle type, tunnel speed limit, number of vehicles involved, and accident type are …

Analysis Of Cracked Body Repaired By Adhesively Bonded Patches By Bem-Fem Coupling, Binh Viet Pham

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents an efficient numerical technique capable of handling the stress analysis of three-dimensional cracked bodies strengthened or repaired by adhesively bonded patches. The proposed technique is implemented within the framework of the coupling of the weakly singular boundary integral equation method and the standard finite element procedure. The former is applied to efficiently treat the elastic body containing cracks whereas the latter is adopted to handle both the adhesive layers and the patches. The approximation of the near-front relative crack-face displacement is enhanced by using local interpolation functions that can capture the right asymptotic behaviour. This also offers …

The Relationship Of Influential Factors On Material Management Effectiveness In Building Construction Projects: Case Study In Vietnam, Bao Van Pham

Chulalongkorn University Theses and Dissertations (Chula ETD)

The improvement of management processes in construction could be seen as one of the important keys to project success in which material management should be appropriately taken into consideration. Although many previous research studies have examined the components of construction material management, the relationship of factors influencing material management effectiveness has not been explored. This study was carried out to identify influential factors on material management effectiveness and develop a model to explain the relationships between these factors and the effectiveness of material management based on practical projects. The research method included the collection of contractors' opinions in building projects …

Sbfe Analysis Of Layered Elastic Media With Consideration Of Surface Energy Effect, Chantha Chhuon

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents an efficient and accurate numerical technique for determining mechanical response of a two-dimensional, infinite, elastic, layered medium under arbitrary surface loading and surface stress effects. Governing equations of a generic bulk layer are formulated from the classical linear elasticity theory via a SBFE technique whereas those of the generic material surface are obtained from a full version of Gurtin-Murdoch surface elasticity theory. The formulation is established sufficiently general allowing both homogenous and functionally graded bulk materials to be treated for each layer. By enforcing the continuity at the interface of the material surface and the bulk, it …

Compression Behavior Of Fire-Damaged Concrete-Filled Steel Tubular Columns Confined With Fiber-Reinforced Polymer Sheets, Dat Thanh Vu

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research investigates the axial compression behavior of fire-damaged circular concrete-filled steel tube (CFST) stub columns externally confined with fiber-reinforced polymer (FRP) sheets. A total of 38 CFST specimens were tested under axial compression to investigate the load capacity, ductility, stiffness and failure mode of fire-damaged CFST columns before and after strengthening with FRP sheets. The test variables include the level of fire damage (no damage and 2-hour ISO standard fire), compressive strength of infill concrete (24MPa and 55MPa), type of FRP sheets (carbon and glass), and the number of FRP layers (0, 1, and 2 layers). The test results …

A Bim-Database-Integrated System For Evaluating Building Life-Cycle Costs Using A Multi-Parametric Model, Hang Thi Thu Le

Chulalongkorn University Theses and Dissertations (Chula ETD)

Life-cycle cost analysis (LCCA) has become an essential requirement of the sustainable procurement for many construction projects. Conventional building LCCA methods are extremely complex and time-consuming due to repetitive works, numerous required data, scattered data inputs, and various regulatory requirements, which subsequently lead to inaccurate building life-cycle costs (LCC). Building information modeling (BIM) offers a revolutionary information technology, which can overcome the asperities of the conventional building LCCA. This research develops the BIM-database-integrated system for evaluating building life-cycle costs using a multi-parametric model (BIM-BLCC). The BIM-BLCC consists of four interrelated modules. The relational database management module collects and organizes the …

Improved Response Spectrum Analysis Procedure For Design Of Reinforced Concrete Tall Buildings, Kimleng Khy

Chulalongkorn University Theses and Dissertations (Chula ETD)

Response spectrum analysis (RSA) procedure commonly used in design practice has been found to underestimate design forces in tall buildings. Failure and damage of reinforced concrete (RC) shear walls in mid-rise and high-rise buildings have been observed in recent earthquakes. In this dissertation, a modified RSA (MRSA) procedure to compute shear forces and strains in RC walls and columns to identify locations requiring ductile detailing was proposed. Six tall RC shear-wall buildings of 15 to 39 stories and four RC moment-frame buildings of 3 to 15 stories subjected to earthquake ground motions expected in Bangkok and Chiang Mai were first …

Development Of Causal Relationship Model Of Knowledge Sharing In Construction Projects, Lambada Roeun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Knowledge sharing among construction project members is very crucial for improving project success and project performance. It can also reduce mistakes in the construction process. Project management has been growing more complicated, and project members need to learn best practice from others. Currently, knowledge sharing is not well performed yet; especially, few research studies have been focused on the relationship evaluation of supporting factors that affect knowledge sharing from different contexts in construction projects. Therefore, this study aims to develop the causal relationship model of supporting factors from psychological, individual, organizational, and technological factors that affect mediators - knowledge sharing …

The Influences Of Granite Particle As A Mixing Material Of High-Strength Concrete, May Thazin Khine

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this study is to investigate the effect of granite particle on the properties of high strength concrete by the partial substitution as fine aggregate. By grouping two categories as concrete with and without admixture is also performed in this experiment. The granite particle substitution percentage for concrete with admixture is set with 0%, 20%, 30%, 40% and 50% by weight of fine aggregate and 0%, 10%, 15% and 20% by weight of fine aggregate for concrete without admixture. The testing of concrete strength is conducted with compressive, split tensile, flexural, water permeability, and microstructure. The result shows …

Geophysical Site Investigation And Ground Response Analysis Of Bangkok Subsoil Due To Earthquake, Muhammad Fatih Qodri

Chulalongkorn University Theses and Dissertations (Chula ETD)

The potential damages on building and infrastructure could be affected by long-distance earthquakes since the vibrations can appear ground motion amplification during the wave propagation. Bangkok urban area is located a hundred kilometers away from the potential area of the earthquake epicenter. However, some people in Bangkok could feel the shaking during the earthquake. It indicates that the long-period shaking could happen during the earthquake. In line with this phenomenon, this study aims to interpret the amplification effect and spectral acceleration in the local site of Bangkok due to remoted earthquakes. The microtremor measurement was conducted at four locations in …

Nonlinear Finite Element Analysis Of Steel Pipe With Stiffener Plate, Rut Su

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents the numerical studies of steel hollow section columns connected to corbels under industry crane loads, and the stiffening design using steel plates to enhance the maximum loading capacity against premature local buckling failures. The influences of inelastic material properties and geometry nonlinearity on the overall load carrying capacity of the columns were considered. Square hollow section columns were modelled in 3D using standard eight-node solid finite elements using an ANSYS software. The plate stiffener design algorithm involving variation of plate thicknesses was coded in MATLAB with a direct application programming interface to ANSYS. The full history of …

Mechanical Performances Of Concrete Beams With Hybrid Usage Of Steel And Frp Reinforcement, Linh Van Hong Bui

Chulalongkorn University Theses and Dissertations (Chula ETD)

Fiber-reinforced polymer (FRP) bars have been recently employed to reinforce concrete members due to their high tensile strength and especially in corrosive environments to improve the durability of concrete structures. However, FRP composites have a low modulus of elasticity and a linear elastic behavior up to rupture, thus reinforced concrete (RC) components with such materials would express a lack of ductility. In order to increase the mechanical performances of RC beams, the hybrid usage (also called combined usage) of FRP and steel reinforcements in shear and flexure is proposed. At first, an experimental investigation of concrete beams strengthened in shear …

Strengthening Of Shear Critical Reinforced Concrete Columns By Steel-Rod Collars, Phawe Suit Theint

Chulalongkorn University Theses and Dissertations (Chula ETD)

The inadequate shear strength of the existing old reinforced concrete columns located in the seismically active areas can lead the catastrophic shear failure. In this study, strengthening of shear-critical reinforced concrete columns by the steel-rod collar method is investigated. This proposed method is less intrusive to the existing building components. The steel-rod collar comprises the four sets of welded steel angles connected by steel-rods threaded at the ends. The three specimens were divided into one unstrengthened column, and the two strengthened columns. All the specimens were tested under the constant axial load and the reversed cyclic loadings. In addition, the …

Habal-Habal: Characteristics Of Motorcycle Taxi Users In Metropolitan Manila, Sebastian Mapili Cano

Chulalongkorn University Theses and Dissertations (Chula ETD)

Motorcycle taxi services in the Philippines (locally referred to as habal-habal) has been deemed to be operating only in rural areas wherein public transportation is inadequate or is utterly absent. It is also perceived as illegal and unsafe for urban operations, especially in a conurbation like Metro Manila wherein more than 30% of recorded fatal road accidents come from motorcycles. However, the worsening traffic congestion in the metropolis has spurred its growing urban presence and has led the attention of commuters to alternative modes of transport that are fast, reliable, and affordable. Inadequate understanding of habal-habal's role in the urban …

Risk Management Of Public-Private Partnership (Ppp) Infrastructure Projects In Laos, Siamphone Maneevong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Public-private partnership (PPP) is a popular option of project delivery and contractual scheme between the public and private sectors public infrastructure projects. Many factors contribute to the success of PPP projects, most of which are country-specific. Since Laos has recently adopted PPP for several infrastructure projects, all stakeholders must understand the critical risks that influence the performance of PPP projects. In this research, we identify, evaluate and rank the critical risk factors and risk categories that affect the PPP project development of in Laos. The questionnaire survey and In-depth interviews were used to gather information from nine respondents, who represent …

A Study Of Applying Para Rubber Sheets In Railway Track By Using Ballast Box Test, Somkith Dethvongsone

Chulalongkorn University Theses and Dissertations (Chula ETD)

Recently, attempts to reduce ballast degradation have been a major topic for many railways and researchers. Nowadays, a successfully proven alternative is applied elastic under-sleeper pads in between sleeper and ballast particles, and also as the ballast mat placed under the ballast layer. The using of synthetic material as the elastic element is able to decrease the deterioration of ballast and vibrations. Para rubber is a natural elastic material and it is abundant in South East Asia countries. Therefore, this study is aimed to investigate using para rubber as an alternative element of reducing ballast breakage in ballasted track. Experiments …

Poroelastodynamic Solutions Of Transversely Isotropic Multi-Layered Media, Suraparb Keawsawasvong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation presents poroelastodynamic fundamental solutions of transversely isotropic poroelastic materials. Analytical general solutions for transversely isotropic poroelastic media under time-harmonic loading are derived for plane strain and axisymmetric problems by applying Fourier and Hankel integral transforms respectively. The fundamental solutions for a homogeneous half-space are then explicitly obtained by solving relevant boundary value-problems based on the derived general solutions. An exact stiffness matrix method is also employed based on the present general solutions to determine the fundamental solutions corresponding to multi-layered transversely isotropic poroelastic media. The obtained fundamental solutions are then employed in the analysis of dynamic interaction problems …

Analysis And Optimum Design Of Cold-Formed Steel Arch Structures, Thu Huynh Van

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents the development of a unified framework for cold-formed steel warehouse design at variations of clear roof spans. The work involves the advanced finite element analyses of nonlinear arch-shape warehouse structures, namely one that considers 2nd-order nonlinear geometry effects-sufficiently accurate approximation of large deformation responses. An optimum design procedure of 3D arch steel warehouse structures is conducted with the help of a novel algorithm, called mixed ESO-PSO approach. The generic idea is based on the implementation of a well-known evolutionary structural optimization algorithm (ESO), and further integrates a mapping, underpinning particle swarm optimization (PSO), technique of design variables …

Tio2 Nanoparticles Coated Forward Osmosis Membranes For Treatment Of Industrial Textile Effluent, Kaung Ko Ko Sint

Chulalongkorn University Theses and Dissertations (Chula ETD)

Textile wastewater occur as demanding water bodies to be treated by membrane separation due to the complex composition and presence of reactive constituents such as heavy metals and salts as well as nutrients, e.g. nitrogen, sulphate and phosphate. Numerous combination of osmosis process with photocatalysts has been experimentally conceived for the water and wastewater treatment and reuse of textile wastewater. The present work was devoted to study the operating feasibility using photocatalyst as TiO2 nano-particles were coated onto two commercially available FO membranes, a cellulose triacetate (CTA) membrane and an aquaporin (AqP) membrane through a specially designed 3-(trimethoxysilyl) propyl methacrylate–polymethyl …

Adsorption And Chemical Cleaning Process Of Anionic And Non-Ionic Surfactants On The Membrane Surface Through The Forward Osmosis Process: Application For Water Reuse, Kaiwit Ruengruehan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Forward osmosis (FO) process, an attractive membrane technologies, have been widely studied and applied in many fields to manufacture the clean water. This work, we focused on the fouling behavior and mechanisms of forward osmosis (FO) fouled by sodium dodecyl sulfate (SDS) as anionic surfactants and of nonylphenol ethoxylate (NPE, NP-40) as nonionic surfactant, including cleaning process to recover the system. FO process was run under different operating conditions (cross flow velocity, pH of feed solution, surfactant concentration). In addition, deionized-water (DI), 0.1 M NaCl, and alkaline solution (NaOH) were applied as agents for the cleaning process. The results revealed …

Roles And Regulation Of The Ai-2 Quorum Sensing Of Vibrio Parahaemolyticus In Nitrification Biofilter Of Shrimp Recirculating System., Monchai Pumkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

Thailand is the largest shrimp producing and exporter among Southeast Asia. Up-to-Date, Recirculating Aquaculture System (RAS) have been developed in order to control water quality and enable to conduct intensive cultivation without limitation of land-based cultivation method. Nevertheless, there is concern about pathogenic contamination in Biofilter. Therefore, the role of biofilter in terms of biosecurity is required to study. Recently, shrimp Early Mortality Syndrome (EMS) as known as AHPND/EMS, has spread to shrimp farm in several areas of Thailand. This contributes to severe productivity losses in the shrimp farm industry. It is evident that the causative agent of AHPND disease …

Information Provision And Economic Approach For Promotion Of Plastic Shopping Bag Reduction In Bangkok, Thailand., Nattapat Piromrat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to study the situations of plastic bag management from stakeholders, current plastic bag use trends, evaluate the effect of information provision and estimate the willingness to pay for plastic bag waste management in Bangkok. Online and field questionnaires had been distributed to collect the data. This study found that the trend of plastic bag use is moderate while most of respondents always reuse their plastic bag. Situations of plastic bag management indicate plastic bags are still distributed for free in the market, but some retailers started not to provide them. The plastic bag production is gradually affected …