Thesis (Ph. D.)--University of Hong Kong, 2007. / Also available online.

Thesis (MSc)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 190-192).

A limited number of studies have been conducted in the literature to examine the effect of stacking sequence and fiber orientation on the compressive behavior of fiber reinforced polymer (FRP) confined concrete. This thesis presents the results of an experimental investigation examining the effect of parameters such as fiber orientation, amount of confinement, and specimen size on the behavior of FRP-confined concrete. As part of the experimental study, a large set of concrete cylinders having two different sizes (100 mm x 200 mm and 150 mm x 300 mm) were jacketed with carbon fiber reinforced polymer (CFRP) sheets having various orientations and tested under pure axial compressive loading. The specimens were confined using various CFRP stacking sequences, with fibers oriented at 0⁰, 90⁰, and ±45⁰ (both unidirectional and woven). Furthermore, within each stacking sequence, the numbers of layers was varied between 4, 6, and 8 to examine the impact of number of plies on the behavior of the FRP-confined concrete cylinders. In addition, the research program included a large number of CFRP coupons made from CFRP laminates having the same properties as the CFRP jackets used in the strengthening of the cylinder series. The analytical program assesses the accuracy and suitability of using various FRP confinement models in the literature to predict the stress-strain response of the confined cylinders tested in the experimental program. The results indicate that parameters such as fiber orientation, stacking sequence, number of confinement layers and specimen size have a direct impact on the strength, ductility and stress-strain behavior of CFRP confined concrete. However, the level of influence varies from one parameter to the other, with the results demonstrating that fiber orientation has a more noticeable effect when compared to the other parameters. The results of the analytical program demonstrate the need to develop reliable confinement models which can take into account the effects of fiber orientation.

A method is developed for construction of deflection curves of beam-columns stressed into plastic range by thrusts and equal end moments producing single curvature bending. Actual deflection curves are plotted for 8x8 WF 31 lb/ft section acted upon by moments and thrusts of different magnitudes. These are used for construction of the end moment vs. end slope diagrams and the interaction curves which present in graphical form the ultimate strength of beam-columns of different lengths under various combinations of thrusts and moments. The latter are compared with similar graphs contained in current specifications. The study is based on moment vs. curvature relations developed at Lehigh University. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

This thesis consists of two parts. The first part describes the analysis and implementation of a finite element computer model for the general prediction of failure of wood members in bending or in combined bending and axial compression. Both instability and material strength failures are included. The program is verified using available analytical and test results. A good agreement with the results predicted by this program is observed. The second part describes a procedure for the structural reliability evaluation of a compression member assuming random loads and material variables. The program developed here for the reliability study links the finite element program and the Rackwitz-Fiessler algorithm for the calculation of the reliability index β. The gradient of the failure function, which is a necessary input to the Rackwitz-Fiessler algorithm, is computed numerically using the finite element routine. The results of the reliability study for a typical column problem are compared against the available results obtained by following the code procedures [as outlined in CAN3-086.1-M84 (1984)] for different slenderness ratios. A performance factor ɸ⍴ = 0.75, for compression members of any length is recommended in order to obtain a more accurate and consistent level of reliability in the design process. It is estimated that if this factor ɸ⍴ = 0.75 adopted in the current design practices, a level reliability index of the order of 4.0 can be achieved. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Master of Science

A consideration of the physical principles involved in evaporative drying of soil indicates that several physical processes might possibly limit the rate of evaporation. These include the rate of supply of energy to the site of evaporation, the rate of transfer of water vapor through the sample or through the atmosphere above the sample, and the rate of unsaturated flow of water to the soil surface or to the site of evaporation.

No description available.