SEISMIC DAMAGE MODEL OF CIRCULAR REINFORCED CONCRETE COLUMNS STRENGTHENED WITH PRESTRESSED CFRP STRIPS

To study the seismic damage behavior of circular reinforced concrete columns strengthened with pre-stressed Carbon Fiber Reinforced Polymer (CFRP) strips, the Park-Ang damage model was modified by studying the test data of 13 RC columns, and then the seismic damage model of circular concrete columns strengthened with pre-stressed CFRP strips was established. According to the nonlinear regression analysis of axial load ratio, longitudinal reinforcement ratio and double transverse confinement from pre-stressed CFRP strips and stirrups, the experienced expression of the combination parameter of the recommended model was proposed. Based on the recommended model, damage indexes corresponding with the feature points of different damage statuses were calculated, and then the criteria for the classification of seismic performance levels for reinforced concrete circular columns strengthened with pre-stressed CFRP were concluded. The finite element analysis results of the damage indexes showed good agreement with the experiment results, which indicates the rationality of the recommended damage model and the classification standards for reinforced concrete circular columns strengthened with pre-stressed CFRP.