Study on the ductility of high strength reinforced concrete columns

Based on the experimental research of 48 reinforced concrete columns with high strength and normal strength concrete under monotonic and cyclic loading, the factors which affect the ductility such as the concrete strength, axial load ratio, stirrup ratio, etc. are analysed. It can be concluded that the axial load ratio is the most important factor that affects ductility. The axial load ratio limits and relative stirrups ratio limits were proposed under the condition of limited ductility (μΔ≥3). The experiments also show that the relationship between stirrup ratio and axial load ratio is not linear if the axial load ratio is high, which is different from previous researches. In the design, a simplified bilinear relationship can be adopted which agrees well the experimental results. (author)