Experimental exercises with the RCM-method

Title: Experimental exercises with the RCM-method
Author(s): M.R. de Rooij, S.M. van Dalen, W.J. Bouwmeester, E.A.B. Koenders
Paper category : conference
Book title: 2nd International RILEM Symposium on Advances in Concrete through Science and Engineering
Editor(s): J. Marchand, B. Bissonnette, R. Gagné, M. Jolin and F. Paradis
Print-ISBN: 2-35158-003-6
e-ISBN: 2351580028
Publisher: RILEM Publications SARL
Publication year: 2006
Nb references: 3
Language: English

Abstract: The Rapid Chloride Migration (RCM) test also known as CTH test or NT Build 492 is rapidly becoming the standard test in Europe for assessing the resistance to chloride ingress in concrete. The principle of the test is based on active chloride migration under the influence of an electric field over a saturated concrete sample. The measurement consists of the depth of penetration into the concrete made visible with a silver nitrate solution. Less penetration under standardized conditions represent a denser concrete, hence (is the assumption) a more durable concrete in terms of chloride resistance.
The nice feature about the test is the possibility to alter test conditions within a certain range without obtaining a different migration coefficient. The given equation in NT Build 492 is derived to handle slight differences in the input values. This part has been put to the test. A research program has been explored in which a number of parameters have been changed like length of the specimen and duration of the test. Furthermore, these tests have been performed on concrete made with ordinary Portland cement and with blast furnace slag cement for a series of water/binder ratios and a variety of ages of the concrete samples.
The article shows that changing the duration of the test has a negligible effect on the migration coefficient given the reproducibility of the test. However, changing the length of the specimen drastically lead to results, which cannot be converted into one another. Larger specimens show a larger migration coefficient. Finally, the test results show that temperature has a stronger effect than is suggested by the current equation for the migration coefficient.

Keywords: chloride ingress, rapid migration test, slag

Online publication: 2006-08-02
Classification: 3.1 Theme 1: Numerical Models: from Microstructure to Transport Properties and Durability
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580028.022