Seismic performance of low-rise building using graded concrete as flexural elements

Graded concrete is a material innovation in the field of civil engineering that aims to create environmentally friendly and economical construction materials. Previous research has shown that graded concrete increases material rigidity so that graded concrete can increase the level of serviceability of structures, indicated by the decreasing of deflection. Investigations on the performance of structures using graded concrete as building material need to be studied further with broader structural indicators. Further studies related to structural performance including base shear reactions, fundamental periods, storey stiffness, storey drift, and storey displacement, should also be discussed. In this study, a 3-storey residential building is modelled using ETABS in 3D approach. The effect of disparity in concrete strength on structural performance is examined. The buildings that employ graded concrete as a construction material can offer a better level of occupant comfort due to the lesser vibration period generated. The application of graded concrete in beam components can increase the value of the storey stiffness. It is because of the greater the modulus of elasticity, the greater the stiffness produced by the beam. It increases the confinement of the enclosed plate so that the stiffness of the building floor also increases. The use of high strength concrete in the beams will change the mode shape of the structure from flexure to shear type. In shear mode shape, the column will form a double curvature so that the mode shape of the structure tends to form a convex pattern. The benefit of the shear-type mode shape is the lesser value of storey displacement at the top level.