Anita Gojević (Author), Vilma Ducman (Author), Ivanka Netinger Grubeša (Author), Ana Baričević (Author), Ivana Banjad Pečur (Author)

Abstract

This paper investigates the effectiveness of a specific crystalline waterproofing admixture (CWA) in concrete as a function of a water–binder ratio. Four concrete mixes with and without CWA were prepared; two of them with a water–binder ratio of 0.45 and two of them with a water– binder ratio of 0.55. Water permeability and compressive strength were tested on hardened concrete specimens and self-healing of cracks over time was observed. Cement paste and CWA paste were prepared to clarify the results obtained on the concrete specimens. SEM and EDS and XRD and FTIR were performed on the hardened pastes to explain the mechanism of CWA working. The results show that the addition of CWA had no significant effect on the compressive strength of the concrete, but reduced the water penetration depth in the concrete, and the reduction was more effective for mixes with lower water–binder ratio. Regarding the self-healing effect, it can be concluded that the addition of CWA improves the crack healing in concrete, but the efficiency of self-healing is highly dependent on the initial crack width. The mechanisms involved in the reduction of water penetration depth and crack healing in concrete can be explained by different mechanisms; one is creation of the CSH gel from unreacted clinker grains, then formation carbonate, and additional mechanism is gel formation (highly expansive Mg-rich hydro-carbonate) from magnesium based additives. The presence of sodium silicate, which would transform into carbonate/bicarbonate, also cannot be excluded.

Keywords

samopopravljivi beton;kristalinični dodatki;mikrostrukturne analize;odprti dostop;slag;self healing concrete;crystal admixture;microstructural analysis;open access;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: ZAG - Slovenian National Building and Civil Engineering Institute
Publisher: Molecular Diversity Preservation International
UDC: 620.1/2
COBISS: 59413251 Link will open in a new window
ISSN: 1996-1944
Views: 7
Downloads: 0
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: Slovenian
Secondary keywords: samopopravljivi beton;kristalinični dodatki;mikrostrukturne analize;
Source comment: Nasl. z nasl. zaslona; Opis vira z dne 143 4. 2021; Št. članka 1860;
Pages: str. 1-14
Volume: ǂVol. ǂ14
Issue: ǂiss. ǂ8
Chronology: 2021
DOI: 10.3390/ma14081860
ID: 19461228