TY - GEN A1 - Bachmann, Robert A1 - Hünger, Klaus-Jürgen T1 - BTU-SP-Schnelltest zur Beurteilung der Alkaliempfindlichkeit von Gesteinskörnungen : die Entwicklung eines direkten Prüfverfahrens T2 - Beton Y1 - 2009 SN - 0005-9846 VL - 59 IS - 4 SP - 138 EP - 143 ER - TY - GEN A1 - Bachmann, Robert A1 - Hünger, Klaus-Jürgen A1 - Scholz, Yvonne T1 - Entwicklung eines direkten Prüfverfahrens zur Alkaliempfindlichkeitsbeurteilung von Gesteinskörnungen : der BTU-SP-Schnelltest T2 - Forum der Forschung Y1 - 2007 SN - 0947-6989 IS - 20 SP - 73 EP - 78 ER - TY - CHAP A1 - Hünger, Klaus-Jürgen A1 - Bachmann, Robert A1 - Scholz, Yvonne A1 - Hübert, Cornelia A1 - Mo, X. ED - Broekmans, Maarten A. T. M. ED - Wigum, Børge J. T1 - An accelerated chemical test method for ASR carried out directly at aggregate grains T2 - Conference proceedings, 13th International Conference on Alkali-Aggregate Reaction in Concrete, Trondheim, Norway, 16 - 20 June 2008 Y1 - 2008 SN - 978-82-7385-128-4 SP - 782 EP - 793 CY - Trondheim ER - TY - CHAP 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 - 2012 UR - https://www-docs.b-tu.de/fg-baustoffe/public/006_021811-BACH.pdf ER -