Application of Laser-Induced Breakdown Spectroscopy for Diagnosis of Degradation of Concrete Structure

Abstract

The measurement of such trace substances as chlorine in concrete is important in evaluateing the durability of reinforced concrete structures because reinforcing bars in concrete are eroded by chloride ions. Laser-induced breakdown spectroscopy (LIBS) is attractive for the fast on-site measurement of trace elements. We measured a chlorine concentration of 0.18 kg/m 3 in concrete. Thus, a chlorine concentration of 0.6 kg/m 3 , at which the reinforcing bars in concrete structures start to corrode, can be detected. We also measured the two-dimensional distribution of the emission intensity of multi-elements on the surface of a concrete specimen's cross-section. These results show that LIBS is an attractive tool for quick, high spatial resolution, and high sensitivity on-site measurement of chlorine concentration in concrete structures. Here we review the LIBS applications for the diagnostics of concrete structures.