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Advances in Concrete Construction
  Volume 7, Number 3, May 2019, pages 167-174
DOI: http://dx.doi.org/10.12989/acc.2019.7.3.167
 


Microstructure modeling of carbonation of metakaolin blended concrete
Xiao-Yong Wang and Han-Seung Lee

 
Abstract
    Metakaolin (MK), which is increasingly being used to produce high performance concrete, is produced by calcining purified kaolinite between 650 and 700oC in a rotary kiln. The carbonation resistance of metakaolin blended concrete is lower than that of control concrete. Hence, it is critical to consider carbonation durability for rationally using metakaolin in the concrete industry. This study presents microstructure modeling during the carbonation of metakaolin blended concrete. First, based on a blended hydration mo del, the amount of carbonatable substances and porosity are determined. Second, based on the chemical reactions between carbon dioxide and carbonatable substances, the reduction of concrete porosity due to carbonation is calculated. Furthermore, CO2 diffusivity is evaluated considering the concrete composition and exposed environment. The carbonation depth of concrete is analyzed using a diffusion-based model. The proposed microstructure model takes into account the influences of concrete composition, concrete curing, and exposure condition on carbonation. The proposed model is useful as a predetermination tool for the evaluation of the carbonation service life of metakaolin blended concrete.
 
Key Words
    metakaolin; carbonation; concrete; model; service life
 
Address
Xiao-Yong Wang: Department of Architectural Engineering, Kangwon National University, Chuncheon, Korea
Han-Seung Lee: Department of Architectural Engineering, Hanyang University, Ansan, Korea
 
References
    -acc0703004-
 

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