Application of LIBS technology for determination of Cl concentrations in mortar samples. (20th April 2019)

• Record Type: Journal Article
• Authors: Mateo, J.; Quintero, M.C.; Fernández, J.M.; García, M.C.; Rodero, A.
• Is Part Of: Construction & building materials. Volume 204(2019)
• Page Start: 716
• Page End: 726
• Publication Date: 2019-04-20
• Subjects: Laser-induced breakdown spectroscopy -- Atomic emission -- Chloride content -- Mortar corrosion -- Building materials; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.01.152
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: LIBS has been shown to be an efficient method to determine Cl content in mortar. LIBS is non-destructive technique that allows measurements without material damage. High resolution metering of mortar affected by Cl ambient can be performed by LIBS. The development of a portable LIBS device will allow fast Cl measurements on-site. Abstract: In a society where the cement and concrete industry is of great importance, the diagnosis of the quality of these materials has become a matter of highest priority. One of the maximum exponents of the deterioration of a reinforced concrete structure is the chloride ion content. In this work it has been shown that its evaluation, traditionally carried out by chemical methods, can also be performed by laser-induced breakdown spectroscopy (LIBS), a much faster and advantageous technique. This work develops an optimal experimental set-up based on the generation of small discharges using a 532 nm Nd:YAG laser of 320 mJ, in a helium atmosphere. The experimental conditions have been optimized and a calibration curve, relating the ratio of intensities of Cl I 837.60 nm and Ca II 849.80 nm obtained from the LIBS and the actual chloride concentration, has been determined from a set of samples with different ion chloride concentrations. These samples have been simultaneously subjected to a traditional chemical analysis, as well as instrumental contrast analysis using energy-dispersive X-ray spectroscopy (EDX). Finally, LIBS technique has been applied to the study of mortar samples that had been submerged in saturated sea salt water for 60 months, and in this way their average ion chloride concentration and their depth profiles have been obtained.