Behavior of High-Strength Concrete Rectangular Columns

This paper summarizes the test results of an extensive research program sponsored by the US Transportation Research Board of the National Research Council to examine the behavior of high-strength concrete rectangular columns subjected to concentric and eccentric loading conditions. The variables considered in this investigation were concrete strength ranging from 7.9 ksi (55 MPa) to 16.5 ksi (114 MPa), longitudinal and transverse reinforcement ratios. Test results were combined with reported data in the literature to examine the validity of the current AASHTO LRFD Bridge Design Specification for high-strength concrete up to 18 ksi (124 MPa). Research findings indicate that the current specification overestimate the load carrying capacity of columns with high-strength concrete under both concentric and eccentric loading conditions. This paper recommends several provisions to the current AASHTO LRFD Bridge Design Specifications to extend the use of high-strength concrete up to 18 ksi (124 MPa) for axially and eccentrically loaded short columns.