Estimation of general corrosion damage to steel reinforced mortar using frequency sweeps of guided mechanical waves

Abstract

A frequency sweep from 50 to 200 kHz of guided mechanical waves has been conducted to detect and assess general corrosion damage in steel reinforced mortar specimens with seeded defects and in specimens undergoing accelerated corrosion using impressed current. The sweep was conducted by primarily invoking the fundamental longitudinal mode of propagation, ie the L(0,1) mode. The change in waveform energy (indicative of attenuation) at different frequencies is presented and discussed in terms of general corrosion damage. The isolated effects of rebar surrounded by water and mortar are also discussed. Experimental results indicate that general corrosion damage can be detected and evaluated by invoking the fundamental longitudinal mode of propagation. Results are presented and discussed within the framework of a corrosion process degradation model and service life. A review and discussion of the corrosion process and service life analysis of reinforced concrete is also presented.