Crack monitoring on concrete structures: Comparison of various distributed fiber optic sensors with digital image correlation method

The quality of strain measurements using distributed fiber optic sensors (DFOS) depends largely on the bond between host material and optical fiber. Experimental investigations were carried out to test suitability five different DFOS types for crack monitoring. subsequently bonded two 4 m long reinforced concrete (RC) beams, so that influence application technique could be evaluated. verified by digital image correlation (DIC) electrical gauges (SGs). For types, clear differences in measured curves determined widths observed. focus was robust DFOS, which can deployed construction sites. Compared layered sensing cable, a monolithic showed distribution with pronounced peaks even closely spaced cracks. obtained integrating high agreement DIC measurements.