Detecting damage and self-healing in cementitious composites using electrical methods for protection of critical infrastructures

Self-healing assessment of sound and pre-loaded Engineered Cementitious Composites (ECCs) incorporating with different pozzolanic materials (PM) was made through different test methods. Different from other studies in literature, direct-electrical-impedance (EI) measurements were used for the first time in the present study to evaluate the self-healing performance along with rapid-chloride-permeability-test (RCPT) and resonant-frequency (RF) measurements. In the dissertation, it also was studied on intrinsic self-healing behavior of ECC as an alternative way to reduce high CO2 emissions in the atmosphere. To compare performance of self-healing at the CO2 environment of the specimens, the specimens were kept in the with and without CO2 cabinets. Experimental findings show that well-fitting exponential relationship exists between EI and RCPT measurements at different ages regardless of the mixture and specimen type. However, results from RF tests do not correlate either with EI or RCPT results which is attributed to the different parameters having parmount influence on the individual tests. Obtained findings also show that self-healing in a CO2-rich environment is more pronounced than it is in normal atmospheric conditions, and PM type can be very decisive on self-healing performance in a CO2-rich environment, depending on testing method. Although results from different tests do not always correlate well among themselves, three different tests used for the present study are capable of monitoring the self-healing behavior with differing efficiencies. Moreover, results suggest that proper material design can lead to the development of environmentally-friendly ECC options with superior mechanical and durability characteristics.