ACR in dolomitic aggregate concrete for an autogenous self-healing processŠtukovnik, Petra (Avtor) Bokan-Bosiljkov, Violeta (Avtor) Marinšek, Marjan (Avtor) alkali carbonate reaction (ACR)self-healingdedolomitisationformation of new phasesmechanical strengthThis paper investigates the process of alkali-carbonate reaction (ACR) in dolomite aggregate concrete in view of its potential as a self-healing process. Samples for the ACR self-healing study were prepared using a cement composite with self-compacting properties in fresh state. The mixture was composed of Portland cement CEM I and typical Slovenian crushed dolomite aggregate in the role of aggregate and stone filler. Samples were subsequently exposed to accelerated testing conditions simulated by 1-M NaOH at 60 °C or deionized water at 60 °C. The conducted research revealed that the complete ACR process was successfully triggered, including the dedolomitization and formation of secondary phases, i.e., CaCO3 called "carbonate halo", Ca-Al-involving phase and some minor phases containing Mg-Al, Mg-Si and/or Mg-Al-Si. Additionally, the "carbonate halo" and Ca-Al-involving phase also precipitated inside purposely preformed cracks in the samples. Smaller cracks up to 200 %m in width were completely filled with the "carbonate halo" and Ca-Al-involving phase. Wider cracks may not have been completely filled with the newly precipitated phases; however, their length and width were also successfully reduced. With filling of the pores and cracks, the mechanical strength of the cement composite was increased substantially due to the ACR self-healing process.20202020-09-25 10:26:27Znanstveno delo120769UDK: 67.017ISSN pri članku: 1580-2949DOI: 10.17222/mit.2019.196COBISS_ID: 20433155OceCobissID: 106193664sl