TY - CONF A1 - Bachmann, Robert A1 - Hünger, Klaus-Jürgen T1 - Interactions of chemical and physical parameters of aggregate grains for a better understanding of alkalisilca-reaction T2 - ICAAR, 14th International Conference on Alkali Aggregate Reaction, May 20-25, 2012, Austin, TX N2 - Mortar bar and concrete prism tests are the most commonly used methods for the evaluation of alkali-silica reactivity (ASR). Despite their widespread use, both methods have significant drawbacks. The largest issue is that neither test is a direct measurement of the aggregate. Matrix effects from the mortar or concrete, or variations in the individual non-aggregate materials can influence the outcome. This paper describes fundamental results as the basis for the chemical and physical test method (BTU-SP test) directly carried out at aggregate grains. Additional methods (BET, microscopy) confirm that not only the aluminate from the aggregate controls the silica release but also the pore structure inside of rocks (i.e. voids, cracks) buffer the swelling potential of the formed alkali-silica gel. As a result a reaction model describing the interactions of chemical and physical parameters in 4 phases has been developed for an alkalisilica reaction. KW - BTU-SP test KW - 4 phases model KW - silica release KW - open porosity KW - alumino silicate formation Y1 - 2018 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/21297 UR - https://www-docs.b-tu.de/fg-baustoffe/public/006_021811-BACH.pdf ER -