Relationship between air permeability and carbonation progress of concrete in Japan

Author(s): K-i. Imamoto, K. Shimozawa, M. Nagayama, J.Yamasaki, A. Tanaka
Paper category: Workshop
Book title: RILEM International workshop on performance-based specification and control of concrete durability
Editor(s): D. Bjegović, H. Beushausen, M. Serdar
ISBN: 978-2-35158-135-3
e-ISBN: 978-2-35158-136-0
Pages: 325 - 332
Total Pages: 8
Language: English

Abstract: 
This study deals with the air-permeability of concrete cover and its relation with carbonation progress. In this study, two test cases were considered. One focused on the air permeability of new concrete and the other on that of existing concrete. In the test with new concrete, 20 concrete specimens with water-to-cement ratios ranging from 0.3 to 1.0 were prepared. The air permeability values of these specimens were measured at the age of 2 months; then, they were subjected to exposure tests. In the test with existing concrete buildings, the air permeability of concrete structures and carbonation progress were measured for 4 buildings and 11 concrete specimens, the ages of which were 12–45 years. It was found that the square root theory–based carbonation velocity increases with an increase in the air permeability coefficient (kT). Good agreement was obtained between the air permeability of new concrete and carbonation velocity. Although the relationship between carbonation velocity and kT for existing concrete buildings had a considerably large scatter, the relationships between them for individual buildings were comparatively good. This might provide a good perspective for evaluating carbonation progress based on the air permeability of the concrete in new and existing structures.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00