For determining the chloride threshold level of steel in concrete, the withdrawal of concrete samples is not a trivial task. The elected sampling method, the associated step size of depth intervals and the depth position of the steel with regard to the interval limits can exert a significant influence on the accuracy of the results. Also local variations of chloride ingress may lead to significant deviations from the effective chloride concentration in the depth of interest. In this paper, the chloride profiles from grinding powder samples with small interval sizes of 2 mm are compared to drilling powder samples with interval sizes of 10, 15 and 20 mm. Regression curves according to Fick’s second law were generated and the corresponding chloride diffusion coefficients were determined. The deviations of the curves and the resulting diffusion coefficients were illustrated. The assumption of considering the determined chloride concentration as constant and valid for the entire interval depth was found to lead to huge deviations from the effective profiles which are not acceptable. The implementation of regression approaches from drilling powder samples lead to an extreme reduction of deviations, thus resulting profiles may be suitable for certain inspection tasks, even though most profiles examined do not exhibit a sufficient number of data points from depth ranges completely controlled by diffusion. Additionally, a theoretical modeling of chloride penetration curves was performed. A quantitative approach for the election of depth intervals in practice was developed based on the input parameters diffusion coefficient and exposure time.
Materials and Structures – Springer Journals
Published: May 29, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera