Delamination Detection of Reinforced Concrete Decks Using Modal Identification

Table 5

Comparison of natural frequencies of the undamaged and delaminated concrete decks for numerical example supported on beams.

Mode	Undamaged		1/4 delaminated		1/3 delaminated
	Mode shape	Freq	Freq	Difference	Freq	Difference
		(Hz)	(Hz)	(%)	(Hz)	(%)
1	1st bending	11.51	11.47	−0.37	11.43	−0.68
2	2nd bending	17.91	17.80	−0.62	17.65	−1.45
3	3rd bending	22.19	21.26	−4.19	19.38	−12.70
4	4th bending	24.33	23.86	−1.92	23.34	−4.07
5	5th bending	37.39	30.05	−19.63	25.00	−33.13
6	6th bending	47.81	35.97	−24.77	33.57	−29.78