Title: Behavior of Hoop Confined Concrete Under High Strain Rates
Author(s): Shuaib H. Ahmad and Surendra P. Shah
Publication: Journal Proceedings
Appears on pages(s): 634-647
Keywords: confined concrete; modulus of elasticity; plain concrete: spiral reinforcement; strains; stress-strain relationships.
Results of an experimental investigation to establish the response of hoop confined concrete when subjected to high strain rates under short-term compressive loading are summarized. Preliminary studies were conducted to study the effect of specimen geometry and gage length on the complete stress-strain curve of concrete. In the final study, the main variables were strength of concrete, amount of confinement, strain rate, and the aggregate type. The experimental program included tests of 42 specimens in the preliminary studies and 94 specimens in the final study. Stress-strain curves of hoop confined concrete under different strain rates are reported. Based on results of normal-weight aggregate concrete, empirical equations are proposed to predict the effect of strain rate on secant modulus of elasticity, maximum stress, and the corresponding strain. A fractional equation is used to predict the stress-strain curve of hoop confined concrete under high strain rates. Comparisons of analytical and experimental curves are presented.