Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 114 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 102-105).

The hydration of cement and water is an exothermic reaction capable of generating significant amounts of heat. Unaccounted for, the heat generated can alter the chemical reaction of the cement, producing massive cracks in the hardened concrete that sacrifice the integrity of the structural element. Alternatively, the heat produced can create thermal gradients capable of cracking the concrete and exposing the reinforcing steel to chlorides. To prevent either of these events from occurring, a software program known as ConcreteWorks was created as part of a previous research project funded by the Texas Department of Transportation. ConcreteWorks gives TxDOT engineers, contractors, and inspectors the ability to manage the structural design, mix proportions, and construction processes in order to minimize maximum concrete temperatures as well as temperature gradients. The free program has seen successful on several non-TxDOT projects, however, it has failed to become incorporated into standard TxDOT practices and specifications. The goal of this research, funded by TxDOT, was to promote widespread use and acceptance of the program within the DOT. In pursuit of this goal, a four-hour hands-on training class was developed and taught throughout the state of Texas, construction projects were selected for the use and validation of the software program, and a few modifications were suggested to make the program more helpful and easy to use. This thesis primarily focuses on the results of the validation of ConcreteWorks on mass concrete and precast applications. In total, four precast beams and two columns were instrumented. With regards to existing methods of predicting temperatures, the program was fairly accurate for mass concrete applications. The program was also very useful for precast elements; however, the lack of variables to match the model to the actual structure likely limits the software program from producing a more accurate prediction. / text

Existing reinforced concrete (RC) beams often need to be strengthened due to material deterioration or a change in usage. The bolted side-plating (BSP) technique, i.e., attaching steel plates to the side faces of RC beams using anchor bolts, effectively enhances the bearing capacity without significant loss in deformability thus receives wide acceptance. However, as a newly developed technique, only limited information is available in literature, which mainly focused on the overall load–deflection performance of lightly reinforced BSP beams. Little studies have been conducted on the partial interaction between steel plates and RC beams which is closely related to the performance of BSP beams. The longitudinal and transverse slips, which control the degree of partial interaction, have yet to be determined precisely. Accordingly, in this thesis, extensive experimental, numerical and theoretical studies on BSP beams are presented. The experimental behaviour of BSP beams was investigated. For the first time, special effort was put in precisely measuring the profiles of longitudinal and transverse slips. In order to investigate the behaviour of BSP beams under other load cases and beam geometries, a nonlinear finite element analysis was conducted. The numerical method is more economical and capable of overcoming the difficulty in measuring the transverse slips precisely. A new approach to evaluating the transverse bolt shear force was also developed through a parametric study. New partial interaction models were developed by isolating and considering the longitudinal and the transverse partial interaction separately. A longitudinal slip model was developed based on the BSP beam section analysis, in which different strains of steel plates and RC beams were considered but the difference in deflection hence the difference in curvature was not taken into account. Meanwhile, a piecewise linear model was also proposed for the transverse slip and bolt shear transfer by introducing Winkler’s model and defining the transverse slip as the difference in deflection. Formulas for the slips, the plate forces, the strain and the curvature factors that indicate the degree of partial interaction, were also deduced. Furthermore, these formulas allow us to evaluate the effect of partial interaction in the BSP strengthening design. A numerical program was originally developed to evaluate the performance of BSP beams with partial interaction. The balance between strengthening effect and strengthening efficiency was also achieved by a parametric optimization study, which would simplify the design procedure of BSP strengthening significantly. According to the numerical and theoretical results, a new design approach for BSP beams, which needs only minor modification to existing design formula for RC beams, was proposed to aid engineers in designing this type of BSP beams and to ensure proper details for desirable performance. Compared to the conventional design methods that assume a full interaction between steel plates and RC beams, this new method not only retains the features such as ease of use and fast calculation, but also yields results that are more reliable. / published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

This thesis is based upon a need to re-examine the assumptions and expand upon the results arrived at in recent studies on the flexural stiffness of reinforced concrete columns. A survey is presented of concrete column design over the last 200 years. Elastic and plastic behavior of concrete columns is discussed with respect to stiffness and Euler's buckling load. Some limitations and applications of buckling load are considered. Various current code approximations of stiffness are presented. Four possible methods for computing a more exact stiffness (EI) and their advantages and disadvantages are discussed. The formula EI = M/φ provides the best solution. The two dimensional program RECTCOL which is based on the P-M-φ relationships is developed and explained. Then RECTCOL is used to show how the column flexural stiffness varies with axial load, reinforcement ratio, yield strength of the reinforcing steel, concrete strength, cover, and column dimensions. A flow chart and source code are included by RECTCOL.

published_or_final_version / Civil Engineering / Master / Master of Philosophy

No description available.

No description available.

No description available.

No description available.

Thesis (MEng) -- University of South Australia, 1991