Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Civil Engineering


The purpose of the overall project was to observe the effect of span length on ultimate moment of concrete beams due to flexure. The general field of structural analysis has made significant advance in recent years due to the combined influence of computer technology, the common use of higher mathematics, and the acceptance of the ultimate moment theory. Since ultimate design has been in great demand, extensive testing and research has been conducted concerning the properties of beams such as I beams, wood beams, plain concrete beams, and reinforced concrete beams. The present equations to predict the ultimate moment of these beams include all the different properties and dimensions of the beams except the span length, i.e, the span length has no effect on the ultimate moment. The probability of reaching failure in the longer span is the same as in the shorter span under the same conditions of loadings; in other words, the span length has no effect on ultimate moment. To study this theory two sets of plain and reinforced concrete beams were cast and tested in the Civil Engineering Laboratories at South Dakota State University. This study, therefore, was conducted to determine the effect of span length on the ultimate moment in plain and reinforced concrete beams.

Library of Congress Subject Headings

Reinforced concrete construction


Includes bibliographical references



Number of Pages



South Dakota State University