ACR in dolomitic aggregate concrete for an autogenous self-healing process

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

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.

• Language: English
• Keywords: alkali carbonate reaction (ACR), self-healing, dedolomitisation, formation of new phases, mechanical strength
• Work type: Scientific work
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2020
• Number of pages: Str. 379-384
• Numbering: Letn. 54, št. 3
• PID: 20.500.12556/RUL-120769
• UDC: 67.017
• ISSN on article: 1580-2949
• DOI: 10.17222/mit.2019.196
• COBISS.SI-ID: 20433155
• Publication date in RUL: 25.09.2020

Record is a part of a journal

• Title: Materiali in tehnologije
• Shortened title: Mater. tehnol.
• Publisher: Inštitut za kovinske materiale in tehnologije
• ISSN: 1580-2949
• COBISS.SI-ID: 106193664

Secondary language

• Language: Slovenian
• Title: Vpliv ACR-reakcije na avtogeno celjenje betonov z dolomitnim agregatom
• Keywords: alkalno karbonatna reakcija (ACR), samoceljenje, dedolomitizacija, oblikovanje novih faz, mehanska trdnost

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: J2-9196
• Name: Masivni betoni - optimiziranje tehnologije ob uporabi naprednih preskusnih metod