No description available.

The stress-strain relationship of concrete in flexure is one of the essential parameters in assessing the flexural strength and ductility of reinforced concrete (RC) structures. An overview of previous research studies revealed that the presence of strain gradient would affect the maximum concrete stress and respective strain developed in flexure. Previously, researchers have conducted experimental studies to investigate and quantify the strain gradient effect on maximum concrete stress and respective strain by developing two strain-gradient-dependent factors k3 and ko for modifying the flexural concrete stress-strain curve. In this study, the author established a new analytical concrete constitutive model to describe the stress-strain behavior of both normal-and high-strength concrete in flexure with the effect of strain gradient considered. Based on this, comprehensive parametric studies have been conducted to investigate the combined effects of strain gradient and concrete strength on flexural strength and ductility design of RC beams and columns with concrete strength up to 100 MP a by employing the strain-gradient-dependent concrete stress-strain curve using non-linear moment-curvature analysis. From the results of the parametric studies, it is evident that both the flexural strength and ductility of RC beams and columns are improved under strain gradient effect. A design value of ultimate concrete strain of 0.0032and anew equivalent rectangular concrete stress block incorporating the combined effects of strain gradient and concrete strength have been proposed and validated by comparing the proposed theoretical strength with the strength of 198 RC beams and 275 RC columns measured experimentally by other researchers. It is apparent from the comparison that the proposed equations can predict more accurately the flexural strength of RC beams and columns than the current RC design codes. Lastly, for practical engineering design purpose, design formulas and charts have been produced for flexural strength and ductility design of RC beams and columns incorporating the combined effects of strain gradient and concrete strength. / published_or_final_version / Civil Engineering / Master / Master of Philosophy

No description available.

No description available.

No description available.

No description available.

No description available.

Thesis (Ph. D.)--University of Wisconsin, 1964. / Typescript. Vita. Bibliography: leaves 159-161.

Thesis (M.S.)--University of Wisconsin--Madison, 1960. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 84).

The optimum design, with respect to cost, of reinforced concrete structures, satisfying Building Code Requirements (ACI 318-63), is investigated, using Box's Complex Method. Variables considered are: geometry, topology, member sizes and material properties. The optimum design, with respect to volume of single span, pin-connected, plane trusses, is investigated, using Box's Complex Method. Variables considered are: member sizes and nodal co-ordinates. The feasibility of the Complex Method is probed by checking the results, either by conducting exhaustive search or comparing them with solutions obtained with linear programming methods. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate