The Finite Element Analysis of Reinforced Concrete Column Strengthened with Concrete Filling and Steel Tubes Jacket
Keywords:
Finite element modeling; strengthened of column; steel tubes; compressive load-shortening curve; confinement factor (CF); concrete contribution ratio (CCR)Abstract
Abstract
Column strengthening is used to restore the ultimate load capacity of RCC. The RCC strengthened contains a reinforcement cage, RCC, filled concrete, and steel tubes. The study was focused on the capacity of RCC strengthened by steel jackets. All parameter were carried out by FE software Abaqus 6.14. Nonlinear behavior of steel tubes, reinforcement and concrete (RCC and fill concrete) are included in FE models. In this paper, 12 specimens taken to evaluate the capacity of RCC, the axial load-shortening curve, and failure modes of column strengthened by steel tube jacket. From output, since the concrete strength increased from C-30 to C-50, the axial force increased by 22.45% and 37.71% of RCC without and with strengthened by steel tubes respectively. similarly, when thickness of steel tubes increased in FE models the axial forces of the column strengthened was increased. As same dynamic load was applied in the model, the RCC without strengthening was more damaged than the strengthened column due to the weight of fill concrete. since the concrete grade was increased the CCR directly increased but, the CF decreased. Similarly, the comparative analysis done between FEA with EC-4 and AISC predictions. The mean values of the Nu, AISC/Nu, FEA ratio is 0.90084 and standard deviation value was 3.90%. The EC4 result yield more acceptance prediction rather than other with the mean values of 0.93075 from Nu, EC4/Nu, FEA ratio, and with 3.77% standard deviations. In both codes, the results predicted were conservative when compared with FE results.
