Small-Column Compression Tests on Concrete Confined by WWF

Tests on 127 × 127 × 381 mm concrete columns were carried out to study the efficacy of welded-wire fabric (WWF) as confining transverse reinforcement in columns. Three different wire spacings and a total of five wire sizes were used. The WWF was placed transversely in columns at close longitudinal spacing. The longitudinal spacing to column width ratio (S/D) varied from 0.1 to 0.3. For each of the five wire sizes, four different S/D ratios were used. This resulted in 20 reinforced column specimen designs. Each design was tested under displacement-controlled uniaxial compression with three identical specimens. The axial stress-strain curves were recorded. For the range of parameters tested, the WWF reinforcement provided varied degree of confinement to the concrete, as reflected in the varied level of enhancement of concrete strength and ductility. The S/D ratio seems to have a more dominant effect on confinement than the volumetric ratio of WWF. From the test results, a relationship between the S/D ratio and the volumetric ratio of WWF was deduced to serve as a boundary separating ductile behavior of the confined concrete from brittle behavior. It is concluded that, with proper design, WWF can be effective in providing lateral confinement to concrete in column construction. Further study using large columns is suggested.