Alkali-dolomite reaction in air lime mortarŠtukovnik, Petra (Avtor) Bokan-Bosiljkov, Violeta (Avtor) Marinšek, Marjan (Avtor) lime mortaralkali-carbonate reactionsmechanical propertiesCaCO$_3$ dissolution/reprecipitationcivil engineering materialsThis paper investigates the origin of increased strength and water resistance of air lime mortar prepared by Triassic dolomite aggregate when exposed to humid or wet environments. The mortar specimens were exposed to various ageing conditions and analysed using petrographic and scanning electron microscopy equipped with X-ray microanalysis. Parallel to these analyses, X-ray powder diffraction and strength tests were performed on the specimens. It was revealed that reactions associated with the dedolomitisation process of the dolomite grains in the lime binder (hereafter alkali-carbonate reactions or ACRs) are the source of the improved strength and water resistance. An increasingly alkaline environment accelerated the ACRs substantially. Two parallel processes during the ACRs (dedolomitisation and CaCO$_3$ dissolution/reprecipitation) were described in detail. Ageing temperature decisively influenced the kinetics of the dedolomitisation and dictated the path of the CaCO$_3$ dissolution/reprecipitation process. After two years of ageing in a water-saturated environment at 60°C, air lime mortar retained a great deal of its initial mechanical strength, and at 20°C its strength was considerably increased. This somewhat unexpected observation was explained as being a result of microstructural changes and/or phase transitions.20202020-04-02 14:30:44Članek v reviji114958UDK: 691ISSN pri članku: 1296-2074DOI: 10.1016/j.culher.2020.02.007COBISS_ID: 9109089OceCobissID: 1228053sl