Influence of carbon dioxide on shrinkage behavior and compressive strength of AAC in accelerated tests

Abstract Background The German application standard DIN 20000‐404:2018‐04 for the use of AAC according to EN 771‐4:2015‐11 describes a method determine long‐term resistance due carbonation. Thus, total value drying shrinkage as specified in 680:2006‐03 must not exceed 0.40 mm/m. This threshold was evaluated using empirical methods. Objective In order verify above threshold, additional studies were carried out this paper on blocks from different manufacturers. Experimental Deviating climate 680:2006‐03, parametric study under laboratory conditions. All specimens stored at relative humidity 80% and carbon dioxide concentration 0.5% by volume. addition behavior, compressive strength behavior with increasing carbonation progress investigated. Results degree individual types progresses rates. that carbonates faster shows greater change length (up about 5.2 mm/m) significant loss 50%). some cases, initially increases before decreasing again. containing fly ash only an increase progressive Conclusions determination appears be most suitable so far identify increased risk towards manageable effort. accompanying tests indicate limit mm/m is also appropriate.