TY - JOUR A1 - Sturm, Patrick A1 - Gluth, Gregor A1 - Jäger, Christian A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten T1 - Sulfuric acid resistance of one-part alkali-activated mortars T2 - Cement and Concrete Research N2 - One-part alkali-activated (geopolymer) mortars based on three different silica-rich starting materials and sodium aluminate, with and without ground granulated blast furnace slag (GGBFS) addition, were tested regarding sulfuric acid resistance according to DIN 19573:2016-03 (70 days at pH = 1). Corresponding pastes were characterized by XRD, SEM, chemical analysis, 29Si MAS NMR and 1H-29Si CPMAS NMR after water storage and after acid exposure. The mortars exhibited a high resistance against sulfuric acid attack, with the best ones conforming to the requirements of DIN 19573:2016-03. The analytical results showed that this was due to precipitation of silica gel at the acid-mortar interface, which formed a mechanically stable layer that protected the subjacent mortar and thus inhibited further degradation. The addition of GGBFS decreased the acid resistance via formation of expansive calcium sulfate phases. PB - Elsevier Ltd. KW - Alkali activated materials KW - Acid resistance KW - Nuclear magnetic resonance KW - One-part geopolymers PY - 2018 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/44722 AN - OPUS4-44722 SN - 0008-8846 VL - 109 SP - 54 EP - 63 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany