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/m3 in concrete. Thus, a chlorine
concentration of 0.6 kg/m3, 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.
