Experimental research was conducted to investigate structural performance o
f reinforced concrete columns confined with welded grids. Ten full-scale co
lumns with different volumetric ratios, spacing, and arrangement of welded
reinforcement grids were tested under simulated seismic loading. The column
s were subjected to constant axial compression accompanied by incrementally
increasing lateral deformation reversals. Results indicate that welded rei
nforcement grids can be used effectively as confinement reinforcement, prov
ided the steel used has sufficient ductility and the welding process employ
ed does not alter the strength and elongation characteristics of steel. The
grids improved the structural performance of columns, which developed late
ral drift ratios in excess of three percent with the spacing and volumetric
ratio of transverse reinforcement similar to those required by the ACI 318
-95 Building Code. Drift capacity further increased when grids with larger
number of cells were used. Furthermore, the use of grids reduced congestion
of reinforcement while the dimensional accuracy provided effective support
to longitudinal reinforcement.