Experimental Study On Seismic Behavior Of Precast Prestressed Self-centering RC Shear Walls

The self-centering structure system is a new type precast system aimed to improve the ability of restoration of the structure after earthquake.Compared with the traditional structure,the self-centering structure system would be damaged slightly with small residual deformation and easy to be repaired after earthquake.In this paper,experimental study on seismic performance of RC self-centering shear walls has been done to provide basic data on the application of the RC self-centering shear walls in our country.In this paper,quasi-static tests have been carried out to study the seismic performance of the RC self-centering shear walls;the test specimens include one castin-place shear wall and four RC self-centering shear walls.Comparison analysis of the cast-in-place shear wall and RC self-centering shear walls has been used to study the different seismic performance of those two wall systems and to study the effect of different moment contribution ratio on the seismic performance of RC self-centering shear walls.In addition,Comparison analysis of RC self-centering shear walls with same moment contribution ratio but different aspect ratio has also been used to study the effect of different aspect ratio on the on seismic performance of specimens.Compared to the cast-in-place walls,RC self-centering shear walls developed with less cracks,and the deformation of the structure was focused on the interface between the base panel and the foundation,present as concrete cover spalling and no significant damage to the upper panel.The cast-in-place RC wall has a full hysteretic curve,and its skeleton curve presents the typical "S" type;Obvious pinching occurs in the hysteresis curves of the RC self-centering shear walls,whose skeleton curve presents multi-lines shape.With the decrease of moment contribution ratio,the ability of energy dissipation increases,but the residual deformation becomes lager and the ability of selfcentering becomes weaker.With same moment contribution ratio but different aspect ratio,the proportion of shear deformation in the specimens with lager aspect ratio is smaller and no shear failure was observed during the test,and the proportion of shear deformation in the specimens with smaller aspect ratio is greater and shear failure occurred during the test;no significant difference has been found in the energydissipating ability of the specimens with same moment contribution ratio but different aspect ratio,but residual deformation of the specimen with smaller aspect ratio is much lesser than the specimen with lager aspect ratio.Based on ACI ITG-5.2 and New Zealand Standard,a method for calculating bearing capacity and the design procedure are summarized.Then the bearing capacity of each specimen at the typical drift is calculated according to this method.According to the results,the calculated value matches the test value quite well.With rational design and proper structural measures,the capacity identical to the cast-in-place walls and good energy-dissipating ability can be achieved by the RC selfcentering shear walls.Since this structure has the characteristics of less damage and easy restoration after earthquake,it can be promoted and used in the seismic zone.