Application of Image Analysis to Identify Quartz Grains in Heavy Aggregates Susceptible to ASR in Radiation Shielding Concrete
Daria Jóźwiak-Niedźwiedzka , Roman Jaskulski , Michał A. Glinicki
AbstractAlkali-silica reaction (ASR) is considered as a potential aging-related degradation phenomenon that might impair the durability of concrete in nuclear containments. The objective of this paper is the application of digital analysis of microscopic images to identify the content and size of quartz grains in heavy mineral aggregates. The range of investigation covered magnetite and hematite aggregates, known as good absorbers of gamma radiation. Image acquisition was performed using thin sections observed in transmitted cross-polarized light with λ plate. Image processing, consisting of identification of ferrum oxide and epoxy resin, and the subsequent application of a set of filtering operations resulted in an adequate image reduction allowing the grain size analysis. Quartz grains were classified according to their mean diameter so as to identify the reactive range. Accelerated mortar bar tests were performed to evaluate the ASR potential of the aggregates. The SiO2 content in the heavyweight aggregates determined using the image analysis of thin sections was similar to XRF test result. The content of reactive quartz hematite was 2.7%, suggesting that it would be prone to ASR. The expansion test, according to ASTM C1260, confirmed the prediction obtained using the digital image analysis.
|Journal series||Materials , ISSN 1996-1944|
|Publication size in sheets||0.5|
|Keywords in Polish||-|
|Keywords in English||alkali-silica reaction; grain size; heavyweight aggregate; image analysis; radiation shielding concrete; reactive aggregate; quartz|
|Abstract in Polish||-|
|Score|| = 35.0, 28-11-2017, ArticleFromJournal|
= 35.0, 28-11-2017, ArticleFromJournal
|Publication indicators||: 2016 = 2.654 (2) - 2016=3.236 (5)|
|Citation count*||4 (2018-02-11)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.