Flexural behaviour of RC columns using wire ropes as lateral reinforcement

Abstract

The use of high-strength, high-flexibility wire ropes for lateral reinforcement in reinforced concrete (RC) columns helps resolve troubles encountered during bending of the high-strength steel bar as well as in the preparation of congested steel bars. Five column specimens were tested to failure under constant axial load and cyclic lateral loads in order to examine the practical application of a spiral-type wire rope for lateral reinforcement in rectangular concrete columns. The main variables investigated were the configuration of spiral wire ropes and the axial load level. The test results were then compared with test results obtained by other researchers for conventional tied columns with rectangular hoops. At a similar lateral reinforcing index level, greater displacement ductility ratios and work damage indicators were observed in the columns containing spiral wire ropes than in conventional tied columns. These results indicate that wire rope is highly effective in enhancing the ductility of columns and preventing the buckling of longitudinal reinforcement. The effect of the configuration of wire rope and the axial load level on the crack propagation and flexural capacity of the columns was similar to the trend commonly observed in tied columns. On the other hand, the flexural capacity and monotonic lateral load–displacement response of RC columns confined with high-strength spiral-type wire ropes could be appropriately predicted by a simple analytical approach derived using the section laminae method and idealised curvature–displacement relationship. Overall, the wire ropes possess great potential for practical applications to lateral reinforcement.