TY - JOUR
T1 - Behaviour of cementitious matrices subjected to the combined action of chloride ions and carbonation
AU - Malheiro, Raphaele
AU - Camões, Aires
AU - Meira, Gibson
AU - Amorim, Maria Teresa
AU - Castro-Gomes, João
AU - Ferreira, Rui Miguel
N1 - Funding Information:
The authors thank the Foundation for Science and Technology (FCT) for supporting this research. The authors also thank the SECIL for making available cement used in this research and the CIMENTEIRA DO LOURO for providing the aggregates used.
Funding Information:
The authors thank the Foundation for Science and Technology (FCT) for supporting this research. The authors also thank the SECIL for making available cement used in this research and the CIMENTEIRA DO LOURO for providing the aggregates used. This work is co-financed by FEDER funds through the Competitively Factors Operational Programme-COMPETE and by national funds through FCT within the scope of the project POCI-01-0145-FEDER-007136.
Funding Information:
This work is co-financed by FEDER funds through the Competitively Factors Operational Programme -COMPETE and by national funds through FCT within the scope of the project POCI-01-0145-FEDER-007136.
Publisher Copyright:
© 2018, Universidade Federal do Rio de Janeiro. All rights reserved.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/10/18
Y1 - 2018/10/18
N2 - Carbonation and chloride action are the two leading causes of degradation in reinforced concrete structures. Despite the combined action of these two mechanisms being a reality, there is little research on the effect of this combination in cementitious matrices. Furthermore, the incorporation of fly ash in cementitious matrices has been frequently used in order to make the matrix more resistant to the action of chlorides. On the other hand, it is known that Ca(OH)2 existing in the matrix is consumed by the pozzolanic reactions, which makes easier the carbonation front advance. Therefore, this paper presents a study of the behavior of cementitious matrices, with and without fly ash, subjected to the combined action of chlorides and carbonation. Two different kinds of mortars were produced: reference (only cement CEM I 42.5R) and fly ash mortar (40% replacement of cement). After curing, the specimens were subjected to three different wetting-drying cycles, considering NaCl solutions and CO2 atmospheres. Afterwards, chloride profiles and carbonation front were measured. Results show that carbonation has a direct influence on chloride penetration, decreasing it for cement mortars with 0% fly ash and increasing it for mortars with 40% cement replacement by fly ash. Moreover, the evolution of carbonation is also influenced by chloride presence, which decreases under the combined action.
AB - Carbonation and chloride action are the two leading causes of degradation in reinforced concrete structures. Despite the combined action of these two mechanisms being a reality, there is little research on the effect of this combination in cementitious matrices. Furthermore, the incorporation of fly ash in cementitious matrices has been frequently used in order to make the matrix more resistant to the action of chlorides. On the other hand, it is known that Ca(OH)2 existing in the matrix is consumed by the pozzolanic reactions, which makes easier the carbonation front advance. Therefore, this paper presents a study of the behavior of cementitious matrices, with and without fly ash, subjected to the combined action of chlorides and carbonation. Two different kinds of mortars were produced: reference (only cement CEM I 42.5R) and fly ash mortar (40% replacement of cement). After curing, the specimens were subjected to three different wetting-drying cycles, considering NaCl solutions and CO2 atmospheres. Afterwards, chloride profiles and carbonation front were measured. Results show that carbonation has a direct influence on chloride penetration, decreasing it for cement mortars with 0% fly ash and increasing it for mortars with 40% cement replacement by fly ash. Moreover, the evolution of carbonation is also influenced by chloride presence, which decreases under the combined action.
KW - Carbonation
KW - Chloride
KW - Fly ash
KW - Mortar
KW - Wetting-drying cycles
UR - http://www.scopus.com/inward/record.url?scp=85055637493&partnerID=8YFLogxK
U2 - 10.1590/S1517-707620180003.0496
DO - 10.1590/S1517-707620180003.0496
M3 - Article
AN - SCOPUS:85055637493
VL - 23
JO - Revista Materia
JF - Revista Materia
SN - 1517-7076
IS - 3
M1 - e-12162
ER -