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Testing boundary conditions determining the drying shrinkage behavior of AAC
Author(s) -
Rzeczkowski Patrick,
Lohaus Ludger
Publication year - 2018
Publication title -
ce/papers
Language(s) - English
Resource type - Journals
ISSN - 2509-7075
DOI - 10.1002/cepa.875
Subject(s) - shrinkage , carbonation , materials science , composite material , humidity , environmental science , thermodynamics , physics
The German application rules DIN 20000–404:2018‐04 for the use of autoclaved aerated concrete (AAC) according to DIN EN 771–4:2015‐11 state that the total value of the drying shrinkage as stated in DIN EN 680:2006‐03 must not exceed 0.40 mm/m. This value was set to determine the long‐term resistance due to carbonation. Such shrinkage tests, therefore, aim to distinguish critical from noncritical AAC blocks. The shrinkage curves of AACs tested in previous investigations differed from the behavior postulated in DIN EN 680:2006‐03. These deviations during shrinkage can be partly attributed to overlapping mechanisms, such as carbonation. In addition, the standard permits different storage conditions. The samples can be stored in either a room or cabinet with temperature and humidity control. In the present study, the possible testing boundary conditions according to DIN EN 680:2006‐03 are investigated to determine and evaluate the effects resulting from different testing boundary conditions and provide recommendations for performing the test. Furthermore, indications of processes in the material structure running parallel to shrinkage are to be derived. The investigations are accompanied by repeated shrinkage tests and thermogravimetric analyses.