TY - CONF A1 - Hüsken, Götz A1 - Wagner, L.-C. A1 - Gluth, Gregor A1 - Pirskawetz, Stephan A1 - Kühne, Hans-Carsten T1 - Application of Steel Fibres in Alkali-Activated Mortars T2 - Proceedings of the 14th International Conference on Local Mechanical Properties - LMP 2019 N2 - Alkali-activated materials are ideal for the repair of concrete structures in harsh environmental conditions due to their high durability in chemically aggressive environments. However, slag-based mortars, in particular, are prone to shrinkage and associated cracks. In this respect, the application of steel fibres is one solution to reduce the formation of shrinkage induced cracks and to improve post cracking behaviour of these mortars. This study investigated the influence of two different types of steel fibres on the tensile properties of two alkali-activated mortars. Direct tensile tests and single fibre pull-outs were performed to analyse the determining failure modes both on macro and micro scale. Mechanical testing was accompanied by non-destructive testing methods such as digital image correlation and acoustic emission for a detailed analysis of the fracture process. T2 - Local Mechanical Properties - LMP 2019 CY - Prague, Czech Republic DA - 06.11.2019 KW - Alkali-activated materials KW - Fibre pull-out KW - Steel fibres KW - Tensile strength PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509291 UR - https://ojs.cvut.cz/ojs/index.php/APP/article/view/6695 DO - https://doi.org/10.14311/APP.2020.27.0090 VL - 27 SP - 90 EP - 95 CY - Prague, Czech Republic AN - OPUS4-50929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor A1 - Hlavacek, Petr A1 - Reinemann, Steffi A1 - Ebell, Gino A1 - Mietz, Jürgen ED - Alexander, M.G. ED - Beushausen, H. ED - Dehn, F. ED - Moyo, P. T1 - Leaching, carbonation and chloride ingress in reinforced alkali-activated fly ash mortars T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2018) N2 - Alkali-activated fly ash mortars were studied with regard to durability-relevant transport coefficients and the electrochemical behaviour of embedded carbon steel bars on exposure of the mortars to leaching, carbonation and chloride penetration environments. The transport coefficients differed considerably between different formulations, being lowest for a mortar with BFS addition, but still acceptable for one of the purely fly ash-based mortars. Leaching over a period of ~300 days in de-ionized water did not lead to observable corrosion of the embedded steel, as shown by the electrochemical data and visual inspection of the steel. Exposure to 100 % CO2 atmosphere caused steel depassivation within approx. two weeks; in addition, indications of a deterioration of the mortar were observed. The results are discussed in the context of the different reaction products expected in high- and low-Ca alkali-activated binders, and the alterations caused by leaching and carbonation. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2018) CY - Cape Town, South Africa DA - 19.11.2018 KW - Alkali-activated materials KW - Steel corrosion KW - Leaching KW - Carbonation PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-464381 DO - https://doi.org/10.1051/matecconf/201819902025 VL - 199 SP - Article Number 02025 PB - EDP Sciences AN - OPUS4-46438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -