Experimental Research on Pre stress Loss of Concrete Circular Columns Confined with Post tensioned FRP

Abstract:

A new self locking anchor (SLA) is proposed in order to apply the lateral pre stress to the concrete columns. By using this device, the lateral fiber reinforced polymer (FRP) sheets can be post tensioned effectively so that the core concrete can be actively confined. Then the strength and ductility of concrete columns can be highly enhanced and strengthened with lateral pre stressed FRP sheets, and the strength of FRP can be fully used. According to the construction process of SLA, the major reason for the lateral pre stress loss is analyzed. Based on the experimental research and theory analysis, including the friction loss，carbon fiber reinforced polymer(CFRP) relaxation loss，concrete creep loss and other factors, various discipline and related relationship are found. Finally, proposals to reduce the lateral pre stress loss are put forward.

Key words:pre stress loss; pre tensioned fiber reinforced polymer; concrete column; self locking anchor system (SLA); active confinement