Experimental Investigation On The Seismic Behaviors Of Severe Earthquake Damaged RC Bridge Piers Repaired With Wrapped CFRP Sheets

Failure or even collapse of bridge structures in past earthquakes were largely,which can bring the severe damages to the buildings.Consequently,it is quite meaningful to study the feasibility of rapid repair of earthquake-damaged bridge piers for the restoration of the transport network to ensure timely earthquake relief work carried out,as well as for reconstruction funds saved.Carbon fiber reinforced polymer or plastics(CFRP) has been widely used as a new material for strengthening existing civil infrastructures because of its superior properties in high tensile strength,light weight,ease for construction,no addition to dimensions of members,etc.However,studies about seismic behavior of earthquakedamaged RC bridge piers repaired with wrapped CFRP sheets is scarce in China.In this paper, a test program on seismic behavior of earthquake-damaged bridge piers repaired with wrapped CFRP sheets,the high-fluidity and early strength concrete is presented.The detail works are summarized as follows:(1)Systematically reviewing the research progress in home and abroad on seismic behaviors of earthquake-damaged RC bridge piers repaired with wrapped CFRP sheets.(2)Six RC bridge piers repaired with wrapped CFRP sheets were tested under cyclic lateral force and a constant load equal to 10%～15%of the bridge piers axial load capacity. The paper has studied the questions such as characteristic of resilience,skeleton curve, degeneration of load,degeneration of rigidity,ductility,energy consumption,the strain of steel hoop and CFRP.The result indicates that repaired with CFRP not only increase bridge piers' ultimate strength but also improve the performance such as energy consumption, ductility and so on.(3) The formula of CFRP amount based on "Code for Design of Highway reinforced Concrete and Prestressed Concrete Bridges and Culverts" has been deduced.At the same time, the reduction factor k showed for the loss of strength in the transverse steel is brought forward while the strain of steel hoop is analyzed.(4) This thesis summarizes the novel ideas and raises some problems for future studies.