Detailed investigation of ACR in concrete with silica-free dolomite aggregate

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

The progress of the alkali-carbonate reaction (ACR) in NaOH or an aqueous environment at elevated tem-perature (60°C) was investigated in concrete prepared with silica-free dolomite aggregate. The resultsobtained show that chemical reactions characteristic for the ACR progressed in all aged concrete systems.In NaOH aged samples, dolomite grains smaller than 2 mm in diameter went through a completededolomitisation process. Additionally, new Mg-Al, Mg-Si and Mg-Al-Si phases were recognized at theaggregate-cement paste interface. The less alkaline environment in the case of H2O-aged samplesresulted in substantially decelerated ACR reaction. Based on observed long-term microstructural andphase changes, a detailed scheme of the ACR in concretes with silica-free dolomite aggregates was pro-posed. It turned out that the soluble Si-source does not necessarily originate from the aggregate itself butrather through the Pozzolanic reaction of cement binder decomposition/regeneration cycle.

• Language: English
• Keywords: alkali carbonate reaction - ACR in concrete, silica-free dolomite aggregate, microstructure investigation, reaction mechanism
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering; FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2019
• Number of pages: Str. 325-336
• Numbering: Vol. 216
• PID: 20.500.12556/RUL-125411
• UDC: 691
• ISSN on article: 0950-0618
• DOI: 10.1016/j.conbuildmat.2019.04.260
• COBISS.SI-ID: 8799841
• Publication date in RUL: 15.03.2021

Record is a part of a journal

• Title: Construction & building materials
• Shortened title: Constr. build. mater.
• Publisher: Scientific & Technical Press
• ISSN: 0950-0618
• COBISS.SI-ID: 25270784

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
• Licensing start date: 15.03.2021

Secondary language

• Language: Slovenian
• Keywords: alkalno karbonatna reakcija, ACR v betonu, dolomitni agregat brez kremena, mikrostrukturne preiskave, reakcijski mehanizem