Effect of Axial Compression Ratio on Seismic and Self-Centering Performance of Unbonded Prestressed Concrete Columns

Table 4

Ductility coefficients of the specimens.

Specimen No.	Loading direction	Yield load	Yield displacement	Peak load	Peak displacement	Ultimate load	Ultimate displacement	Ductility coefficient	Ductility coefficient average
PTRC-1	Forward direction	168.29	11.22	200.71	29.92	170.60	51.16	4.56	4.75
	Reverse direction	−160.80	−12.07	−173.20	−32.92	−147.22	−59.52	4.93
PURC-1	Forward direction	178.26	15.73	201.06	25.00	170.90	53.84	3.22	3.29
	Reverse direction	−188.98	−16.02	−195.19	−30.24	−165.91	−56.94	3.35
PURC-2	Forward direction	153.26	17.35	188.50	28.02	160.23	62.86	3.62	3.60
	Reverse direction	−154.33	−17.89	−193.57	−35.85	−164.53	−63.83	3.57
PURC-3	Forward direction	189.97	15.22	211.16	22.82	179.47	53.53	2.94	2.92
	Reverse direction	−185.96	−16.59	−219.83	−24.90	−178.36	−50.97	2.90
PURC-4	Forward direction	161.42	14.45	192.14	27.56	163.32	54.05	3.29	3.41
	Reverse direction	−163.77	−14.94	−192.46	−34.99	−163.59	−59.57	3.52