Civil Engineering Commons^™

Investigation Of Control Parameters, Strategies, And Transport Modeling For Effective Electrokinetic Nanoparticle Treatment Of Cementitious Materials, Huayuan Zhong

Doctoral Dissertations

Various deleterious chemical species (including sulfates, chlorides, and others) contaminate concrete structures which are inherently porous and thus suffer from compromised durability. Several technologies have been developed for repairing concrete or enhancing the service life. Nevertheless, their efficiency, practicability, and cost can vary widely. Compared with chemical grout, fiber wrap, and traditional repair technology, electrokinetic nanoparticle treatment (EN) has been found to provide remarkable benefits for strength restoration and mitigation of durability problems via porosity reduction. Nanoparticle instability and over dosage issues can arise and lead to problems during treatments. In many cases, these treatment processes have been accompanied by …

Lateral Torsional Buckling Resistance Of Continuous Steel Stringers In Existing Bridges, Dinesha Malky Kuruppuarachchi Kuruppuarachchi Appuhamilage Don

Doctoral Dissertations

Some of the Louisiana’s bridges built in the 1950s and 1960s used two-girder or truss systems, in which floorbeams are carried by main members and the continuous (spliced) stringers are supported by the floorbeams. The main members are either two edge (fascia) girders or trusses. When the flexural capacity of continuous stringers is calculated, the moment gradient factor (Cb) is not accurately calculated considering the lateral torsional buckling (LTB) at the negative moment section. In particular, the bracing effect of the non-composite concrete deck is not accounted for, and as a result, the current practice has underestimated the LTB strength …

Valorization Of Secondary Agriculture Residues, Narendra Kumar

Doctoral Dissertations

Secondary agriculture residues have the potential to be major contributors as resources for energy and sustainably sourced materials production. Separating secondary agricultural residues, which have already been transported to processing centers, into individual biomass components could convert these wastes into bioproducts. Many types of pretreatments to achieve this separation involve chemicals that are hazardous for the environment. Several deep eutectic solvents (DES) that are biocompatible have been investigated for their ability to deconstruct rice hulls and sugarcane bagasse. Mass yield, enzymatic hydrolysis of the pretreated biomass, fiber analysis, and Fourier transform infrared spectroscopy have confirmed that the DES formic acid:choline …

Collaborative Planning In The Construction Industry: A Holistic Framework For Assessing Collaborative Planning Practices And Predicting Project Performance, Amr Elsayegh

Doctoral Dissertations

"The fragmentation of the construction industry prompted developing novel methods such as collaborative planning, lean construction, advancements in technology, integrated project delivery, and relational contracting. Current research focused on specific facets of collaborative planning without presenting a comprehensive analysis of its factors. As such, the goal of this research is to develop a holistic framework that studies and evaluates collaborative planning practices in construction projects. This research offers significant addition to the body of knowledge through various theoretical and practical contributions. In relation to that, this research developed a comprehensive framework by (1) identifying a comprehensive list of factors influencing …

Studies On Tornado-Structure Interactions And Guidance On Design Tornadic Wind Loading, Zhi Li

Doctoral Dissertations

“Tornadoes are violent natural hazards that could caused significant property loss and fatalities. Statistical data indicates that most fatalities during tornado incidents were caused by the building failure under tornadoes. For example, in the 2011 Joplin Tornado, 161 people were killed, and 84 percent of the fatalities were related to the failure of buildings. In addition, most of the significant, tornado-induced property loss and fatalities are relevant to the tornadoes passing through the densely populated regions. Besides buildings, bridges were also severely damaged or destroyed by tornadoes in the United States. To reduce the tornado-induced loss, it is imperative to …

Experimental And Numerical Studies Of Novel Thermal Energy Storage Materials For Applications In Concrete And Energy Storage Systems, Wenyu Liao

Doctoral Dissertations

In this work, several types of novel thermal energy storage (TES) materials and composites are explored, and a series of numerical simulation models and experimental protocols are developed to evaluate the potentials of these materials to be applied in concrete, pavement, and thermal energy storage systems.

The first two types of novel TES materials/composites are at the micro-scale, which use micro diatomite (DE) and cenosphere (Ceno) as carriers of phase change material (PCM), respectively. The third type of novel TES material is at the macro-scale, utilizing lightweight sand (LWS) and lightweight coarse aggregate as carriers to load PCM. The last …

Innovative Modeling And Management Of Infrastructure Systems, Engineering And Construction Operations, And Offsite Construction Technology Using Computational Data Analytics, Rayan Hassane Assaad

Doctoral Dissertations

“The construction industry has been facing considerable challenges due to the inadequacy of the traditional methods in executing, managing, and modeling infrastructure and construction projects. While many techniques have been developed to improve the decision-making process in the industry, there is no evidence of sufficient and continuous improvements in the industry’s adoption and implementation of innovative techniques such as new management approaches, modern modeling methods, and emerging computational data analytics. To this end, the goal of this research is to address some of the recent challenges faced in the industry with a focus on infrastructure asset management, construction engineering and …

Reveal Wind Loading Of Tornadoes And Hurricanes On Civil Structures Towards Hazard-Resistant Design, Ryan Honerkamp

Doctoral Dissertations

"Extreme winds impacting civil structures lead to death and destruction in all regions of the world. Specifically, tornadoes and hurricanes impact communities with severe devastation. On average, 1200 tornadoes occur in the United States every year. Tornadoes occur predominantly in the Central and Southeastern United States, accounting for an annual $1 billion in economic losses, 1500 injuries, and 90 deaths. The Joplin, MO Tornado in 2011 killed 161 people, injured more than 1000, destroyed more than 8000 structures, and caused $2.8 billion of property loss. Hurricanes occur predominantly on the United States East coast regions and along the coast of …

Use Of Portable Seismic Property Analyzer And Ground Penetrating Radar To Assess Bridge Decks, Samie Ramadan A Hamad

Doctoral Dissertations

The Montauk Bridge deck was assessed based on the portable seismic property analyzer and ground penetrating radar data. Based on the analysis of the portable seismic property analyzer data, it was determined that over 65% of bridge conditions were rated serious to poor condition with an average compressive strength of less than 2500 psi; less than 35% of bridge deck conditions were rated fair to good with an average compressive strength over 2500 psi. Based on ground penetrating radar data, it was determined that 72% of the bridge deck was in serious to poor condition, and only 28% of the …

Hydromechanical Stress And Internal Erosion Under Earthen Structures, Kerry Allen Magner

Doctoral Dissertations

"Dam failures by seepage and internal erosion have reportedly been attributed to up to 40% of all dam failures in the United States. Backwards piping erosion either through the embankment or foundation soils has been reported to be the major contributing method to seepage and internal erosion dam failures. This proposed research is motivated by the lack of understanding of the complex stress regimes associated with internal erosion in cohesionless soils under earthen structures. The overall goal of this research is to provide a fundamental understanding of internal erosion and the hydromechanical stress conditions necessary for the initiation and continuation …

Fiber Reinforced Polymer Bar Investigation: Long-Term In-Situ Durability And Bond Strength Assessment In Conventional And Sustainable Concrete, Ali Fadhil Al-Khafaji

Doctoral Dissertations

"Corrosion of steel reinforcement and carbon dioxide emissions are two major global problems. Different methods, techniques, and materials have been implemented to mitigate these problems. Glass fiber-reinforced polymer (GFRP) bar presents itself as a solid alternative to replace conventional steel reinforcement owing to its fantastic features in resisting corrosion. Its demand is progressively increasing. Cement-based concrete, on the other hand, is not eco-friendly due to the excessive amount of carbon dioxide (CO₂) emissions yielded from its cement production. One of the alternatives used to mitigate the use of cement in concrete is fly ash. Fly ash is considered …

Characterization Of Alaskan Modified Asphalt Binders And Mixtures, Jun Liu

Doctoral Dissertations

"Modified asphalt binders and mixtures have been used more in recent years in Alaska. However, there has not been systematic characterization and performance data development for these materials. This study intends to systematically characterize the Alaskan asphalt binders and mixtures and identify the performance benefits of these materials through laboratory tests and field sections monitoring. The research contains five sections: 1) a comprehensive characterization on the morphologies, chemical and rheological properties of modified asphalt binders and mechanical properties of asphalt mixtures with these modified asphalt binders. The lab testing results were further confirmed through field surveys of recent paving projects …

Bond Behavior Of Advanced Fiber Reinforced Composite-Concrete Joints, Xingxing Zou

Doctoral Dissertations

“Externally bonding advanced composite materials to concrete structures is an effective way to improve their strength, ductility, and durability. The interfacial bond behavior is fundamental to understand the overall structural performance of concrete structures strengthened with advanced composite materials. This study includes a comprehensive investigation of the bond behavior of composite-concrete joints with different fiber reinforced composite types. First, a direct approach to determine the bond-slip relationship for fiber reinforced cementitious matrix (FRCM)-concrete joints based on fiber strain measurements was proposed. Then, an analytical solution to predict the full-range response of FRCM-concrete joints was derived by assuming a trilinear bond-slip …

Seismic Behavior Of Composite Bridge Columns, Mohanad M. Abdulazeez

Doctoral Dissertations

“This study investigates experimentally and numerically the seismic behavior of large-scale hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) innovative bridge columns as a sustainable approach to endure and rapidly recover from natural disasters such as earthquakes. The HC-FCS column consisted of a concrete shell sandwiched between an outer fiber-reinforced polymer (GFRP) tube and an inner steel tube to provided continuous confinement for the concrete shell along with the height of the column. The columns have a slender inner steel tube with diameter-to-thickness (D_s/t_s) ratios ranged between 85 to 254. Each steel tube was embedded into the footing, while the …

Studying The Effects Of Various Process Parameters On Early Age Hydration Of Single- And Multi-Phase Cementitious Systems, Rachel Cook

Doctoral Dissertations

”The hydration of multi-phase ordinary Portland cement (OPC) and its pure phase derivatives, such as tricalcium silicate (C₃S) and belite (ß-C₂S), are studied in the context varying process parameters -- for instance, variable water content, water activity, superplasticizer structure and dose, and mineral additive type and particle size. These parameters are studied by means of physical experiments and numerical/computational techniques, such as: thermodynamic estimations; numerical kinetic-based modelling; and artificial intelligence techniques like machine learning (ML) models. In the past decade, numerical kinetic modeling has greatly improved in terms of fitting experimental, isothermal calorimetry to kinetic-based modelling …

Minimizing The Negative Effect Of Pumping On Scc Freeze-Thaw Durability, Daniel Galvez-Moreno

Doctoral Dissertations

“The durability of concrete must be ensured to reduce the carbon footprint of the production of portland cement. If concrete is properly designed to preserve its integrity under adverse exposure conditions, the service life of the material can be extended with minimum maintenance. Nevertheless, bad handling, placing, finishing or curing practices can abate the durability potential and service life of even the best mix design. Pumping concrete is a very efficient placing technique that offers significant cost reduction and versatility at the jobsite, but it also has the potential of altering the air void system parameters, which are key to …

Complexities Observed During The Development Of A Rheological Testing Procedure For Small Cement Paste Samples, Aida Margarita Ley-Hernandez

Doctoral Dissertations

“Rheology has been widely used to describe the flow properties of fresh cement-based suspensions. The use of a rheometer to characterize these properties is not a straightforward task due to the dependency to different preparation conditions, mixing processes, testing procedures and measuring instruments employed. In addition, shear and time dependency of the material which undergoes chemical and physical particle bonding, caused by hydration of cement and flocculation. Nevertheless, the characterization and understanding of the rheological behavior of cement-based materials have become essential with the recent introduction of novel applications like digital construction in the field of civil engineering, among others. …

Detection And Elimination Of Rock Face Vegetation From Terrestrial Lidar Data Using The Virtual Articulating Conical Probe Algorithm, Kenneth John Boyko

Doctoral Dissertations

"A common use of terrestrial lidar is to conduct studies involving change detection of natural or engineered surfaces. Change detection involves many technical steps beyond the initial data acquisition: data structuring, registration, and elimination of data artifacts such as parallax errors, near-field obstructions, and vegetation. Of these, vegetation detection and elimination with terrestrial lidar scanning (TLS) presents a completely different set of issues when compared to vegetation elimination from aerial lidar scanning (ALS). With ALS, the ground footprint of the lidar laser beam is very large, and the data acquisition hardware supports multi-return waveforms. Also, the underlying surface topography is …

Chemically-Bonded Enamel-Coated Steel Pipelines For Corrosion Protection And Flow Efficiency, Liang Fan

Doctoral Dissertations

"This study is to explore and develop chemically-bonded enamel coating (200-300 um) on steel pipes, when subjected to soil and thermal environments, in order to improve the corrosion protection and safety of hazardous liquid and natural gas pipelines while reducing pressure loss. Out of five types of enamels and their various mixtures, Tomatec slurry and GP2118 powder were selected for steel pipeline applications. They were applied at approximately 810 °C to the inside surface of steel pipes in wet and electrostatic processes, respectively. The thickness and surface roughness of the enamel coating were measured using a gauge and an optical …

Development Of Lidar Assisted Terrestrial Radar Interferometry For Rock Deformation Monitoring, Ricardo Javier Romero Ramirez

Doctoral Dissertations

"Rock and soil slope movements cost millions of dollars annually. During the past few decades, engineers have relied on traditional methods to detect slope movements. These tools are valuable for small spatial areas but, may not be adequate or cost effective for large spatial areas. Remote sensing methods such as terrestrial laser scanning (TLS) and terrestrial radar interferometry (TRI) provide excellent spatial coverage, and with adequate post-data-processing software, sub-millimetric scale deformation sensitivity can be achieved.

This work will present a comparative experimental study between TLS and TRI. The comparative experimental study will allow us to achieve the two main objectives …

Dynamic Impact Induced By Tornadoes Through Simulations Based On Two-Way Wind-Structure Interactions, Tiantian Li

Doctoral Dissertations

"Tornadoes have become a significant cause of property damage, injuries and life losses. Investigations of tornadoes indicate that most fatalities were caused by building failure. For example, in the Joplin, MO tornado of 22 May 2011, 161 people were killed, and 84% fatalities were related to building failure. Therefore, it is imperative to develop science-based tornado-resistant building codes, in order to provide a better level of occupant protection from tornadoes and to minimize the tornado-induced damage. This requires in-depth understanding of the wind characteristics of tornadoes and their wind effects on civil structures, based on which design tornadic wind loading …

The Mechanics Of Precision Presplitting, Anthony Joseph Konya

Doctoral Dissertations

"Precision Presplitting is a widely used method of presplit blasting for the mining and construction industries. In recent years considerable effort has gone into the development of empirical equations based on field data to be able to better design the Precision Presplit for various rock types and structural environments. However, the most widely discussed theory about the mechanics of the presplit formation, that of shockwave collisions, does not appear to be applicable for this method of presplitting.

This research has disproven this theory based on insufficient magnitude of the shockwave from modeling with basic wave mechanics. Other authors have suggested …

Feasibility And Assessment Of Using Recycled Rubber For Infrastructure Applications, Ahmed A. Gheni

Doctoral Dissertations

“The United States needs to mine billions of tons of raw natural aggregate each year. At the same time, millions of scrap tires are stockpiled every year. Therefore, replacing natural aggregate with recycled crumb rubber aggregate will be beneficial to the construction industry and environment. This research aimed to investigate the feasibility of using recycled rubber in new construction applications. Based on size, recycled rubber was selected to match its natural counterpart. Different ratios of recycled crumb rubber were used as a fine aggregate replacement in concrete masonry units (CMUs) where the rubberized units showed a lower unit weight, higher …

Use Of Wicking Geotextile To Dehydrate Road Embankments, Chuang Lin

Doctoral Dissertations

“Excess water within a pavement structure is the major cause of pavement deteriorations. A roadway is often constructed with soils compacted at the optimum water contents to achieve the best performance. After construction, the soil water content variation is controlled by the ambient environment. The base course aggregate is very sensitive to water content variations. Unfortunately, conventional drainage system can only drain gravity water, but not capillary water, and it cannot work under unsaturated conditions. Consequently, no matter how well the road is constructed, the water content is expected to increase with time and the excess water will inevitably accelerate …

Long-Term Behavior Of Fiber Reinforced Polymer (Frp) Confined Concrete Cylinders Subjected To Severe Weather And Seawater Solution Conditions, Song Wang

Doctoral Dissertations

"This study presents an experimental investigation on durability of fiber-reinforced polymer (FRP) confined concrete cylinders subjected to various environmental conditions. Two types of cylinders were tested in this experiment: concrete-filled FRP tube (CFFT) and hollow-core FRP-concrete-steel (HC-FCS), with FRP tubes having two different constitutive resin components: polyester and epoxy. The specimens were subjected to three different environmental conditions: combined freeze/thaw, wet/dry and heating/cooling cycles with options of continuous water immersion and sustained axial load in an environmental chamber, UV exposure in an UV chamber, and seawater immersion in water tanks with sustained axial load. Mechanical and material characterization tests were …

Dragline Excavation Simulation, Real-Time Terrain Recognition And Object Detection, Godfred Somua-Gyimah

Doctoral Dissertations

"The contribution of coal to global energy is expected to remain above 30% through 2030. Draglines are the preferred excavation equipment in most surface coal mines. Recently, studies toward dragline excavation efficiency have focused on two specific areas. The first area is dragline bucket studies, where the goal is to develop new designs which perform better than conventional buckets. Drawbacks in the current approach include operator inconsistencies and the inability to physically test every proposed design. Previous simulation models used Distinct Element Methods (DEM) but they over-predict excavation forces by 300% to 500%. In this study, a DEM-based simulation model …

Multi-Scale Investigation Of Microstructure, Fiber-Matrix Bond, And Mechanical Properties Of Ultra-High Performance Concrete, Zemei Wu

Doctoral Dissertations

"The main objective of this study is to provide new insights into enhancing fiber-matrix bond and mechanical properties of ultra-high performance concrete (UHPC). Three main strategies were investigated: 1) use of supplementary cementitious materials; 2) use of nano-particles; and 3) use of deformed fibers. A multi-scale investigation involving the evaluation of non-fibrous UHPC mortar phase (matrix), fiber-matrix interface phase, and then UHPC composite material was undertaken to determine microstructural characteristics, fiber bond to matrix, and key mechanical properties of the UHPC matrix and UHPC. Test results indicate that the incorporation of 10%-20% silica fume effectively improved the fiber-matrix bond and …

Sensitivity Of Rheological Properties Of Cement Paste With Scc Consistency, Azadehalsadat A. Asghari

Doctoral Dissertations

"Robustness, which is defined as the capacity of a mixture to tolerate small variations in constituent elements, mixing parameters or temperature that are inevitable with production at any significant scale, is a key property to expand the practical implementation of self-consolidating concrete (SCC). At the first step, the effect of different amount of water, amount of superplastizer, mixing time, mixing speed and the addition time of superplastizer on the rheological properties of cement pastes with SCC consistency, has been evaluated. Two different SCC mix design concepts, the powder-type and VMA-type were selected for this research. The results show that the …

Bio-Inspired Geomaterial Improvement And Development Of Innovative Characterization Methods, Junnan Cao

Doctoral Dissertations

"This study experimentally investigated the bio-inspired improvement on geomaterials, including enzyme induced calcite precipitation (EICP) and biopolymers. This study also developed several innovative characterization tools to advance the state-of-the-art testing techniques, including SIP-BE column, rotational sedimental panel, and backpressure saturated constant hydraulic gradient break through column. Firstly, EICP test was performed on Ottawa 50-70 sand in a newly developed SIP-BE column. Nondestructive techniques -- spectral induced polarization (SIP) and bender element were used to monitor the precipitation process and shear wave velocities (V_s). SIP, V_s, and SEM results all suggest contact cementation as the preferential precipitation …

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 …