Eighteen short concrete columns reinforced with longitudinal steel and elli
ptical hoops were tested to failure under monotonic uniaxial compression. T
he effects of the amount of lateral reinforcement and the Shape of the elli
ptical hoops on the behavior of columns were investigated. The results indi
cate that elliptical hoops can provide effective lateral confinement of con
crete that increases the strength and ductility of concrete The effectivene
ss of such confinement diminishes as the aspect ratio, that is, the ratio o
f the major axis 2A to the minor, axis 2B (designated as A/B), increases an
d becomes insignificant when A/B is greater than 2.6. The strength enhancem
ent is linearly proportional to the volumetric ratio of the lateral reinfor
cement, but decreases linearly with the increases in A/B. The confinement f
rom the elliptical hoops increases the strain at peak stress, but the incre
ase is not linearly proportional to the volumetric ratio of the lateral rei
nforcement.