An Experimental Study of the Feasibility of Identifying the Impact Damages of Reinforced Concrete Piers Using a Modal Frequency Method

Table 9

Identification of the pier damages using the ultrasonic velocities of the test columns.

Specimen	Impact time	Impact velocity (m/s)	Impact energy (J)	Average acoustic velocity (m/s)		Damage factor D2
				Before impact	After impact
Z16-1	1	1.181	836.8566	4.796	4.577	0.089241
	2	1.376	1136.026	4.577	4.565	0.094010
	3	1.589	1514.953	4.565	4.471	0.130938
	4	1.717	1768.853	4.471	4.315	0.190525
Z20-1	1	1.047	657.7254	4.554	4.419	0.058410
	2	1.354	1099.99	4.419	4.355	0.085486
	3	1.603	1541.765	4.355	4.315	0.102208
	4	1.806	1956.982	4.315	4.104	0.187864
Z16-2	1	1.378	1139.33	4.369	4.181	0.084209
	2	1.336	1070.938	4.181	4.08	0.127920
	3	1.316	1039.114	4.08	3.886	0.208882
	4	1.316	1039.114	3.886	3.677	0.291690
Z16-3	1	1.496	1342.81	4.597	3.901	0.279883
	2	1.496	1342.81	3.901	3.888	0.284675
	3	1.471	1298.305	3.888	3.681	0.358816
	4	1.549	1439.641	3.681	3.542	0.406326
Z20-2	1	1.587	1511.141	4.449	3.802	0.269703
	2	1.587	1511.141	3.802	3.648	0.327666
	3	1.587	1511.141	3.648	3.596	0.346697
	4	1.587	1511.141	3.596	3.504	0.379698