Collapse Behavior of Low Strength Concrete under Cyclic Loading

Abstract

The paper aims at investigating the failure mechanism of extremely poor quality reinforced concrete (RC) columns with very low amount of longitudinal reinforcement ratio recommended by design standard. This type of column was generally found in many developing country. Four column specimens representative of poor quality columns with similar axial stress but different longitudinal reinforcement ratios and concrete strength were test under cyclic loading. The test result revealed that the lateral drift of the column with higher strength is larger compared to those with lower strength. The amount of longitudinal reinforcement ratio did not significantly affect the maximum drift at collapse but may affect axial shortening at the stage near collapse. It was evidently observed that the axial shortening of the column at the nearly collapse stage of column with higher longitudinal reinforcement ratio is lower than those with lower ratio.