An innovative approach for measuring chloride threshold levels in reinforced concrete

Title: An innovative approach for measuring chloride threshold levels in reinforced concrete
Author(s): N. Silva, T. Luping, S. Rauch
Paper category : conference
Book title: 3rd International PhD Workshop on Modelling the Durability of Reinforced Concrete
Editor(s): R. M. Ferreira, J. Gulikers, C. Andrade
Print-ISBN: 978-2-35158-095-0
e-ISBN: 978-2-35158-094-3
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 28 - 34
Total Pages: 7
Nb references: 17
Language: English

Abstract: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful analytical technique that has been used successfully in many fields such as geology, biology and materials sciences but has very limited application in concrete technology. Its main advantage is the possibility to spatially identify and quantify trace elements in solid samples at a micro or meso-scale level. This paper presents the potential application of LA-ICP-MS for the measurement of the critical chloride level (Ccr) leading to the depassivation of steel at the concrete-steel interface. In the paper, the state-of-the-art regarding the determination of Ccr is reviewed and preliminary experimental work concerning the instrument calibration and detection limit is presented. Using cement pastes and finely ground pressed concrete with different chloride content, the influence of different operating conditions was studied in order to optimize the method’s sensitivity. Calcium was determined as an indicator of cement content. Within a resolution range smaller than 300 µm. correlation coefficients of over 0.94 between the chloride to calcium signal intensity ratio and the chloride content were obtained. The results showed that it is possible to use this technique for the intended purpose. Further improvements regarding reproducibility of the method are under development.

Online publication: 2010-02-22
Publication type : full_text
Public price (Euros): 0.00