Papers by Keyword: Large Eccentricity

Abstract: The article proposes a new approach to improving the methodology for calculating the bearing capacity of the eccentrically compressed reinforced concrete elements for cases of their loading with large eccentricities. The basis of this technique is considered as a modified version of the deformation model for the reinforced concrete resistance force. The main feature of this model is the energy approach to transforming the reference diagrams of compression and concrete tension into the diagrams of non-uniform deformation, corresponding to the stress-strain state of the compressed and stretched zones of concrete in the cross section of the eccentrically compressed reinforced concrete structures. This way there is no falling branch in the concrete diagrams obtained by this method. A calculation diagram of the steel reinforcement deformation with a physical yield point was taken as a partial function, consisting of one linear and two non-linear equations. The proposed method also shows the possibility of taking into account the greatest curvature of an eccentrically compressed reinforced concrete element in the plane of its loading. The article presents all the necessary dependencies allowing the theoretical value of the carrying capacity of an eccentrically compressed reinforced concrete element determination. The results of the numerical studies performed using the design software developed by the authors for the personal computer are given.

Abstract: Based on concrete creep calculation model B3 and mechanical characteristics of concrete-filled steel tube (CFT) beam-column members of large eccentricity, a creep calculation model of CFT beam-column members of large eccentricity is constructed, which accords with mechanisms of concrete creep, and creep characteristics of concrete core of CFT beam-column members of large eccentricity have been taken into account. The model is verified against previous creep experiments for CFT beam-column specimens, by changing model B3 for ACI209, CEB90, GL2000 model, elastic continuation and plastic flow theory. The results show that introduction of model B3 to predicting creep of CFT beam-column members with a large eccentricity is necessary. Using the model, a study is then carried out on the effects of practical design parameters, such as concrete mix (e.g. water to cement ratio ( ), aggregate to cement ratio ( )), steel ratio and eccentricity ratio, on creep of CFT beam-column members with a large eccentricity.