Experimental Study on Detection of Deterioration in Concrete Using Infrared Thermography Technique

Table 5

Results of detecting the defective area after the 20-minute heating cycle.

Defect	Dimension (cm cm)	Depth (cm)	Actual area (cm^2)	Estimated area (cm^2)	Error (%)
D1	3 3	3	9	N/A	N/A
D2	5 5	3	25	18.0
D3	7 7	3	49	43.9
D4	10 10	3	100	85.6
D5	3 3	2	9	8.0
D6	5 5	2	25	23.5
D7	7 7	2	49	45.5
D8	10 10	2	100	92.7
D9	3 3	1	9	8.8
D10	5 5	1	25	26.1	4
D11	7 7	1	49	51.2	5
D12	10 10	1	100	106.8	7
S1	5 20	3-1-3	100	82.3
S2	5 20	1-3-1	100	94.7

Note: (−) a negative sign means that the estimated area is smaller than the actual area.
(+) A positive sign means that the estimated area is larger than the actual area.