Petra Štukovnik (Author), Violeta Bokan-Bosiljkov (Author), Marjan Marinšek (Author)

Abstract

This 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.

Keywords

alkali carbonate reaction (ACR);self-healing;dedolomitisation;formation of new phases;mechanical strength;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UL FGG - Faculty of Civil and Geodetic Engineering
UDC: 67.017
COBISS: 20433155 Link will open in a new window
ISSN: 1580-2949
Parent publication: Materiali in tehnologije
Views: 987
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Other data

Secondary language: Slovenian
Secondary title: Vpliv ACR-reakcije na avtogeno celjenje betonov z dolomitnim agregatom
Secondary keywords: alkalno karbonatna reakcija (ACR);samoceljenje;dedolomitizacija;oblikovanje novih faz;mehanska trdnost;
Type (COBISS): Scientific work
Pages: str. 379-384
Volume: ǂLetn. ǂ54
Issue: ǂšt. ǂ3
Chronology: 2020
DOI: 10.17222/mit.2019.196
ID: 12046436