Experimental study on eccentric compression behavior of hybrid strengthened square timber columns

Abstract:

To tackle the problems of strengthening and repairing ancient timber columns, this paper proposes an economic and feasible method of strengthening. Seven square timber columns were strengthened with carbon fiber reinforced polymer (CFRP) strips and steel bars to investigate changes in bearing capacity and ductility under eccentric compression, mainly considering the amount of embedded bars and the eccentricity of timber columns. Test results show that the failure of the hybrid strengthened timber column which was wrapped with a layer of CFRP strips at intervals and embedded with steel bars occurred mainly in the interval between the CFRP strips, indicating a better integrity than the unstrengthened timber columns. When the eccentricity was 0, all four sides of the timber column were destroyed; with the eccentricity increased, the timber column was destroyed only on the pressure side. Under the same eccentricity, the bearing capacity and ductility of the hybrid strengthened timber columns were improved obviously, and the extent of improvement increased with the increase of the amount of steel bars. With the same strengthening method, when the eccentricity increased from 0 to 50 mm, the bearing capacity of the timber column decreased significantly, but the ductility coefficient was little affected.