| dc.description.abstract | There are two parts in this thesis. In first part, a triaxial confined model for evaluating the stress-strain behavior of RC short columns with external confinement is proposed. It’’s valid for rectangular and circular section. In the second part, by using the confined concrete stress-strain relationship in the first part, the flexural behavior of the columns is then predicted. In the study, the confining material comprises steel hoop, FRP and steel plate respectively. In this thesis, a computer program was developed to evaluate the RC columns confined with different confining materials basing on the Mender’’s triaxial arching confined model, by using the average stress-strain to perform the section analysis, hence apply the moment-curvature area method to the prediction of flexural behavior of columns.
In the investigation of arching effect, concrete columns expend due to the axial compression, hence a passive confinement were activated, induced an arching effect, the arch curve as a parabola, and the initial angle of the parabola have a great influence in the load capacity of the columns. The arching angle of the parabola must be taken care while the analysis is performed. By using the modified Mander confined model, the poisson’s ratio of 0.5, and a suitable arching angle are selected to predict the confined behavior of the columns in a accurate way. As a result of analysis, it found that dual confinement (from hoop and FRP confinement) have a better enhancement in load bearing capacity than the single confinement. However, the experimental result did not agree with the results of flexural analysis well. This is due mainly to the influence of shear and fixed end rotation on not accounting for the prediction. The effect of the shear deformation and fixed end rotation will be followed up in the future. | en_US |