Effect of monotonic lateral load on the performance of reinforced graded concrete column, an experimental study

A gradation pattern in the strength of concrete columns is unavoidable due to the presence of static and dynamic segregation. The effect of concrete uniformity on columns subjected to monotonic lateral load is investigated experimentally in this study. Reinforced concrete columns with cross- sectional dimensions of 150 x 150 mm and a height of 1000 mm are prepared as graded concrete column (GCC) specimens and controlling specimens. The columns are designed with a reinforcement ratio of 1%. Two concrete mixes with a strength of 20 MPa and 30 MPa are cast in moulds using the gradual compaction procedure to create a satisfactory strength transition throughout the specimens' height. The resulting lateral deformation and resisting load are utilised for further analysis. The analyses show that the GCC exhibits a lower peak load and lateral deformation than the control specimen, and a distinct failure mode is observed. The GCC also shows more brittle behaviour in the post-peak region.