Civil Engineering Commons^™

Experimental And Predicted Behavior Of Frp Beam-Columns Including Retrofitting, Ali Al-Huazy

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of a theoretical and experimental study of Fiber Reinforce Polymer (FRP) beam-columns with uniaxial bending and including retrofitting. The research involved the design and fabrication of a testing apparatus which was then used for a series of beam-column tests. Three different types of beam-column cross sections were used, namely, channel section, I-section, and square tube section. Six non-retrofitted beam-columns were tested in addition to two retrofitted ones. The members were subjected to an eccentric vertical load applied through a lever arm generating gradually increasing axial load and uniaxial bending moment up to the maximum load. …

Effect Of Void Geometry On Strength, Stiffness, And Failure Modes Of Rock-Like Materials, Omed Yousif

UNLV Theses, Dissertations, Professional Papers, and Capstones

The host rock of portion of the first proposed high-level nuclear waste repository in the United States of America (Yucca Mountain, Nevada) is tuff rock that contains voids (lithophysae) with different shapes, sizes, and distributions. The existence of these voids can cause a dramatic change in the rock's mechanical properties such as uniaxial compressive strength, UCS, and Young's modulus, E. Accordingly, in an experimental program, the effects of void existence on the engineering properties of the tuff rocks was explored in a work of US Department of Energy conducted in the Department of Civil and Environmental Engineering and Construction of …

Stabilization Of Iron Mine Tailings Through Microbially Induced Calcite Precipitation, Noah D. Buikema

Dissertations, Master's Theses and Master's Reports - Open

Mine tailings are deposited into large-scale impoundments. Seasonal temperature fluctuations destabilize particles on the impoundment surface. Wind-induced shear stresses on the destabilized particles can in turn result in suspension of micron-sized particles into the atmosphere, creating dust storms that pose hazards to humans and the environment. Thus, efficient and sustainable methods of dust abatement are needed. One novel method for controlling dust emissions is biomodification. For example, Sporosarcina pasteurii can promote biocalcification in soil via ureolysis. However, application of this method to fined grained materials, such as mine tailings, is challenging. The goal of this work was to perform a …

Geomechanical Characterization Of Marcellus Shale, Rafael Villamor Lora

Graduate College Dissertations and Theses

Given their potential applications for a number of engineering purposes, the geomechanics of shale reservoirs is becoming one of the most important issues in modern geomechanics. Borehole stability modeling, geophysics, shale oil and shale gas reservoirs, and underground storage of CO2 and nuclear waste are some of these potential applications to name a few. The growing interest in these reservoirs, as a source for hydrocarbons production, has resulted in an increasing demand for fundamental material property data.

Laboratory analysis and constitutive models have shown that rock elastic and deformational properties are not single-value, well-defined parameters for a given rock. Finding …

Mechanical Behavior Of Grouted Sands, Ryan C. Ortiz

Theses and Dissertations--Civil Engineering

Grouting techniques have been in used for many years, but several new grout materials have surfaced in recent decades that have re-defined the boundaries of the limitations of grouting programs. Typically these applications are used for seepage control in earthen impoundments, but strength of these earthen impoundments should be considered where there is potential for movement in the grouted soil mass. This study investigated initial conditions that could affect grout application effectiveness. The initial conditions in question were soil grain size and in situ moisture content. Two grouts were used, ultrafine and acrylate, and variations in pure grout properties were …

Mechanical Characteristics Of Organically Modified Fly Ash-Kaolinite Mixtures, Xin Kang

Doctoral Dissertations

"Fly ash is a hazardous waste material to the environment. Beneficial reuse of fly ash, however, brings economic and environmental benefits, i.e., decreases the cost of disposal, reduces greenhouse gas emission, and improves mechanical properties of construction materials. Due to the lack of pozzolanic properties, the reuse rate of Class F fly ash in geotechnical engineering is relatively low (ACAA 2013). In order to promote the effectiveness and sustainability of high volume reuse of class F fly ash in geotechnical engineering, biopolymers (Chitosan, and Xanthan gum) and synthetic polymers (Polyethylene Oxide, PEO) were used instead of the traditional stabilizers to …