Factors affecting AgNO₃ colorimetric method for measurement of chloride migration in cement-based materials

Author(s): C. Shi, X. Wang, X. An, Q. Li, F. He, C. Chen
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 124 – 125
Total Pages: 2
Language: English

Abstract: 
In this paper, mechanism of AgNO₃ colorimetric measurement, measured and calculated values of chloride concentration at the color change boundary (Cd) were reviewed and discussed. Factors influencing Cd were discussed and error of chloride migration measured by AgNO₃ colorimetric method was evaluated. Results indicated that calculated, Cd range properly explains why measured Cd reported in many publications varies in a board range. Sprayed volume and concentration of AgNO₃ solution are main factors in determining Cd. The established AgNO₃ spraying procedure and Cd = 0.2 mol/L is reasonable for measuring and calculating non-steady-state chloride migration coefficient (Dnssm) and apparent chloride diffusion coefficient (Dapp). Based on established spraying procedure, the error of Dnssm can be less than 5% even when Xd < 5mm. However, determination of surface chloride concentration mainly determines error of Dapp. When average chloride ion chloride concentration in the first 2mm layer of specimens is similar to that in the contact solution, Dapp values measured by AgNO₃ colorimetric method is very similar to those measured by NT build 443.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00