Digital Commons Network^™

Field Implementation Of Cement-Based Composite Strengthening Technologies, Michael Andrew Janke

Masters Theses

"With infrastructure continuing to age, technologies are being developed to strengthen structures as a more sustainable option than replacement. The use of fiber-reinforced cementitious matrix (FRCM) strengthening systems is a promising new technology for adding flexural and shear capacity to existing reinforced concrete members. While cement based systems with carbon, PBO, and steel have all been implemented in a lab setting, there is not research data available for installation in the field. FRCM composites have advantages over more widely used fiber reinforced polymer (FRP) composites such as heat resistance and compatibility with concrete substrate. FRP systems have previously been field …

Numerical Modeling Of Capillary-Driven Flow In Open Microchannels: An Implication Of Optimized Wicking Fabric Design, Mehrad Gholizadeh Ansari

Masters Theses

"The use of microfluidics to transfer fluids without applying any exterior energy source is a promising technology in different fields of science and engineering due to their compactness, simplicity and cost-effective design. In geotechnical engineering, to increase the soil's strength, hydrophilic wicking fibers as type of microfluidics have been employed to transport and drain water out of soil spontaneously by taking advantage of natural capillary force without using any pumps or other auxiliary devices. The objective of this study is to understand the scientific mechanisms of the capability for wicking fiber to drain both gravity and capillary water out of …

Examination Of Shear Friction Design Provisions, Nikkolas J. Edgmond

Masters Theses

"This thesis reports the results of research conducted to establish a state-of-the-art database of shear-friction studies to be turned over to ACI Committee 445-0D as a living document, utilize a subset of the established database to examine the effectiveness of the ACI 318 Code (2014), PCI Design Handbook (2010), AASHTO LRFD Bridge Design Specification (2016) and CSA A23.3 Design of Concrete Structures Standard (2014) provisions to predict shear transfer strength, and examine the effective coefficient of friction (µ_e) approach allowed in the PCI Design Handbook (2010).The shear friction design concept is applicable in conditions where direct shear must …

Bioaccessibility Of Lead From Contaminated Soil Using Phosphate Treatment -- Physiologically Based Extraction Test And In Vitro Gastrointestinal Method Test, Austin Charles Doss

Masters Theses

"Phosphate treatments are used to immobilize lead in soil by forming pyromorphite. Soil from Bonne Terre, Mo was collected to study whether such treatment decreases the bioaccessibility of lead. The soil was treated using 0.5 soil wt% of phosphate. Treatments were: none, phosphoric acid, triple super phosphate, and organic bone meal. Each sample was studied after one, four, sixteen, and twenty weeks; during this time span, water was added approximating the average rainfall rate. Percolated water was collected to test the leached phosphate concentrations. Phosphate was below the detection limit in that leachate. Remediated soil samples were used in Physiologically …

Simultaneous Enhancement Of Fluidity And Thixotropy Of Vibration-Free Concrete, Piyush Rajendra Lunkad

Masters Theses

"This research articulates the development of a vibration-free concrete for slip-form paving enabling a simple and rapid construction process. To achieve this, properties such as rheology including thixotropy, shape stability, and workability loss with time are mainly investigated. Concrete mixture with high thixotropic strength and its shape holding ability, flowability, and workability retention with time is evaluated. This study consists of two phases: (1) selection of paste component from rheology of cement paste incorporating various micro- and nano- sized particles (2) study of fresh properties of concrete mixtures using the excess paste layer concept.

From the cement paste study, it …

Nonlinear Finite Element Analysis Of Concrete Columns Subjected To Complex Loading, Adam Christopher Morgan

Masters Theses

"This study details the development and implementation of a finite element model within a commercial finite element code, Abaqus CAE, for the analysis of reinforced concrete (RC) bridge columns containing interlocking spirals subjected to combined loading conditions including axial, shear, bending, and torsional loads, including the post-peak response. The model is a first of its kind attempt at simulating the response of RC columns with continuous spiral transverse reinforcement and subjected to combined loading conditions including torsion. The model is utilized to determine the quasi-static load-deformation response under various proportions of the input loads and displacements. The resulting quasi-static load-deformations, …

Cellulose And Sulfate Degradation In A Biochemical Reactor During Treatment Of Mine Drainage, Sweta Ojha

Masters Theses

"Seventy-two biochemical reactors were set up, and operated using a mixture of chip-bark, horse manure, and gravel as the biochemical treatment substrate. The simulated mine water containing sulfate (1000 mg/l) was pumped into each reactor at a flow rate of 0.5 ml/minute (approximate), giving an empty bed contact time of 8 days. The main idea is that the microorganisms present in horse manure would convert the cellulose in chip-bark into volatile fatty acids. The produced volatile fatty acid would enhance the metabolism of sulfate-reducing bacteria (SRB) initially present in horse manure, which would degrade (and eventually remove) the sulfate from …

Compressive Behavior Of Masonry Columns Confined With Steel Reinforced Grout (Srg) Composite, Sarah Elizabeth Jemison

Masters Theses

"In this study, a new type of composite comprised of steel fiber cords embedded in a natural hydraulic lime mortar matrix, known as steel reinforced grout (SRG), is explored for the use in confinement of masonry columns. An experimental study was carried out to understand the behavior of solid clay brick masonry columns confined by SRG jackets. Twenty-four confined and seven unconfined columns with a square cross-section were tested to failure under a monotonic concentric compressive load. Test parameters considered were the column corner condition, number of fiber jacket layers, and number of fiber overlapping faces. SRG confinement improved the …

Imaging The Subsurface In Eastern Part Of Lake Chesterfield Using A Combination Of Geophysical Tools, Jiawei Li

Masters Theses

"The Lake Chesterfield North Dam in Wildwood city, Missouri has been leaking, more or less continuously since the dam was constructed in 1986 despite mitigation efforts in 1988, 1994, 1995, 2004, and 2005. Neither the grouting efforts in 1988, 1994, 1995, 2004 or 2005, nor the placement and rehabilitation of an impervious clay liner in 2005 has solved the problem. Indeed, in June of 2017, the water level in Lake Chesterfield dropped at an alarmingly rapid rate.

Prior to authorizing additional mitigation work, the Lake Chesterfield Home Owners Association (LCHOA) decided to acquire geophysical data across the dry lake bed. …

Cyclic Axial Compression Behavior Of Concrete-Filled Hybrid Large Rupture Strain Frp Tubes, Monika Nain

Masters Theses

"This study introduces an experimental investigation of the behavior of concrete filled fiber reinforced polymer (FRP) tubes (CFFTs) under cyclic axial compression. The FRP used in this study were either small rupture strain FRP (SRS-FRP) or large rupture strain FRP (LRS-FRP). This paper also presents the first-ever experimental study on the behavior of concrete confined using hybrid LRS-FRP and SRS-FRP. LRS-FRP included PEN (polyethylene napthalate) and PET (polyethylene terephthalate) where both of them having ultimate axial strain larger than 5%, and low stiffness. SRP-FRP included carbon and glass FRP having small rupture strains, smaller than 2%, and high stiffness. The …

Numerical And Experimental Analysis Of Local Buckling Of Axially Loaded Steel Tubes Confined By Concrete And Frp, Nicholas Colbert

Masters Theses

“The hollow core Fiber-Reinforced-Polymer (FRP) concrete circular-steel (HC-FCS) column consists of an outer circular fiber reinforced polymer (FRP) tube, an inner thin-walled circular steel tube concentrically aligned, and a concrete shell between them. Research has been performed on the performance of the member as a whole, but to date, there has been no investigation into the behavior of the steel tube confined in the column. 17 small-scale columns were tested under axisymmetric axial compressions applied directly to the steel tube under displacement control. The conducted parametric study examined the effects of diameter-to-thickness (D/t) ratio, concrete unconfined compressive strength, FRP thickness, …

Thermal Curing Efficiency Of Geopolymer Mortars, Simon Peter Sargon

Masters Theses

”Missouri is the fourth largest coal consumer in the U.S. with coal-fired power plants generate 81.3% of the electricity in the state which generate about 2.7 million tons of coal combustion residuals (CCRs) annually. The CCR, including fly ash, disposal issue is not limited to Missouri, rather it is a national issue with CCRs being the second largest waste stream in the U.S. Ninety million tons of fly ash are stored in landfills and ash ponds annually. Hence, using this waste product effectively is necessary. One of the emerging applications of fly ash is to use it as binder in …