Delamination Detection of Reinforced Concrete Decks Using Modal Identification

Table 4

Comparison of natural frequencies of the undamaged and delaminated concrete decks for numerical example under C-F-C-F support condition.

Mode	Undamaged		1/6 delaminated		1/5 delaminated		1/4 delaminated
	Mode shape	Freq	Freq	Difference	Freq	Difference	Freq	Difference
		(Hz)	(Hz)	(%)	(Hz)	(%)	(Hz)	(%)
1	1st bending	29.19	28.06	−3.87	27.50	−5.79	25.54	−12.51
2	2nd bending	31.96	31.02	−2.96	30.74	−3.81	30.05	−5.98
3	3rd bending	41.76	39.82	−4.63	36.82	−11.83	33.23	−20.43
4	4th bending	60.66	43.60	−28.13	41.32	−31.89	39.89	−34.23
5	5th bending	73.71	57.95	−21.38	56.44	−23.43	53.08	−28.00
6	6th bending	76.94	72.13	−6.25	69.77	−9.32	60.70	−21.11