Seismic Performance Of Reinforced Concrete Special-shaped Column

Reinforced concrete special-shaped columns structure has much evident superiority.The width is equal between column and infilled wall. This avoids bulge of column inroom, and makes better use of available space, and improves the esthetic appearance ofstructure. It brings flexibility and convenience for the residential building design andapplication. In our country has been widely used in residential constructionIn this paper, Opensees was used to simulate tests of reinforced concretespecial-shaped columns under low-cyclic reversed loading, and the hystereticperformance was studied. Through choosing the proper material constitutive relations,restoring force models of section and element types, the finite element models ofl-shaped, t-shaped and cross-shaped three types of reinforced concrete special-shapedcolumn and frame with reinforced concrete special-shaped column were established.The calculated results were agreed to the experimental results. According to thecalculated results, the moment-curvature hysteretic loops of column roots andstress-strain loops of reinforcements and concrete, and the moment-curvature hystereticloops of beam and column of frame with reinforced concrete special-shaped columnswere obtained and analyzed, from which the mechanical properties of reinforcedconcrete special-shaped column and frame with reinforced concrete special-shapedcolumn were known. Furthermore, the parametric analysis of hysteretic properties ofreinforced concrete special-shaped columns and frame with reinforced concretespecial-shaped column was carried out from concrete strength, steel strength, axialcompression ratio, reinforcement ratio and the parameters of the steel bar diameter andso on several aspects.(1) for reinforced concrete special-shaped column, with the increment of concretestrength, the horizontal bearing capacity of the columns is increased, but the ductilityand capacity of energy dissipation are reduced. With the increment of reinforcementstrength, the horizontal bearing capacity and ductility of the columns are both increased,but the capacity of energy dissipation is reduced. With the increment of the axialcompression ratio, the horizontal bearing capacity of L-shaped and T-shaped columns isincreased at one loading direction and decreased at another loading direction, and thereis no significant effect on the horizontal bearing capacity of+-shaped columns. The ductility of all shaped columns is reduced, and the capacity of energy dissipation isincreased. With the increment of reinforcement ratio, the horizontal bearing capacity,ductility and capacity of energy dissipation of the columns are all increased.(2) For frame with reinforced concrete special-shaped columns, with the incrementof concrete strength, the horizontal bearing capacity of the frame is increased, but theductility is reduced. With the increment of reinforcement strength, the horizontalbearing capacity and ductility of the frame are both increased. With the increment of theaxial compression ratio, the horizontal bearing capacity of the frame is insignificantlyreduced, and the ductility is reduced too. With the increment of reinforcement diameter,the horizontal bearing capacity and ductility of the frame are both increased.According to the above research, the results can provide scientific basis andtechnical support for the engineering practice of reinforced concrete special-shapedcolumns, so can popularize the application of the structure.