Carbonation front progress in mortars containing fly ash considering the presence of chloride ions

R. Malheiro, A. Camoes, Miguel Ferreira, G. Meira, T. Amorim, R. Reis

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

3 Citations (Scopus)

Abstract

The incorporation of fly ash (FA) in cementitious matrices have 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 partially consumed by the pozzolanic reactions, which facilitates the advancement of carbonation. Given that the combined action between carbonation and chloride penetration is a fact little known, we speculate about the behaviour of the matrix in this context. This study investigates the influence of the presence of chlorides on the carbonation in mortars with FA. Samples with 0% and 40% replacement of cement CEM I 42.5 R for FA were molded with water/binder 0.56 and 0.52 respectively. After 90 days of curing the specimens were subjected to cycles of immersion/drying for 56 days. Half of the samples was subjected to the following cycle: two days in a solution containing NaCl (concentration equal to 3.5 %); 12 days in the carbonation chamber (4% of CO2). The other half was: two days in water; 12 days in the carbonation chamber. Then, the development of carbonation was evaluated. The results indicate that the presence of chlorides influences the carbonation. The specimens submitted to the exclusive action of CO2 showed a greater depth of carbonation compared to that presented by the specimens subjected to combined action. This may be related to changes in properties of the matrix which may lead to further refinement of the pores and related to the presence of the salt that can lead to partial filling of the pores and the increase in moisture content.
Original languageEnglish
Title of host publicationSustainable Construction Materials
EditorsJosé Aguiar, Aires Camões, Raul Fangueiro, Rute Eires, Sandra Cunha, Mohammad Kheradmand
Pages214-221
DOIs
Publication statusPublished - 2015
MoE publication typeA4 Article in a conference publication

Publication series

SeriesKey Engineering Materials
Volume634
ISSN1013-9826

Fingerprint

mortar
fly ash
chloride
matrix
ion
moisture content
cement
penetration
replacement
salt
water

Keywords

  • carbonation
  • chloride
  • fly ash
  • durability
  • interaction
  • diffusion
  • permability

Cite this

Malheiro, R., Camoes, A., Ferreira, M., Meira, G., Amorim, T., & Reis, R. (2015). Carbonation front progress in mortars containing fly ash considering the presence of chloride ions. In J. Aguiar, A. Camões, R. Fangueiro, R. Eires, S. Cunha, & M. Kheradmand (Eds.), Sustainable Construction Materials (pp. 214-221). Key Engineering Materials, Vol.. 634 https://doi.org/10.4028/www.scientific.net/KEM.634.214
Malheiro, R. ; Camoes, A. ; Ferreira, Miguel ; Meira, G. ; Amorim, T. ; Reis, R. / Carbonation front progress in mortars containing fly ash considering the presence of chloride ions. Sustainable Construction Materials. editor / José Aguiar ; Aires Camões ; Raul Fangueiro ; Rute Eires ; Sandra Cunha ; Mohammad Kheradmand. 2015. pp. 214-221 (Key Engineering Materials, Vol. 634).
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abstract = "The incorporation of fly ash (FA) in cementitious matrices have 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 partially consumed by the pozzolanic reactions, which facilitates the advancement of carbonation. Given that the combined action between carbonation and chloride penetration is a fact little known, we speculate about the behaviour of the matrix in this context. This study investigates the influence of the presence of chlorides on the carbonation in mortars with FA. Samples with 0{\%} and 40{\%} replacement of cement CEM I 42.5 R for FA were molded with water/binder 0.56 and 0.52 respectively. After 90 days of curing the specimens were subjected to cycles of immersion/drying for 56 days. Half of the samples was subjected to the following cycle: two days in a solution containing NaCl (concentration equal to 3.5 {\%}); 12 days in the carbonation chamber (4{\%} of CO2). The other half was: two days in water; 12 days in the carbonation chamber. Then, the development of carbonation was evaluated. The results indicate that the presence of chlorides influences the carbonation. The specimens submitted to the exclusive action of CO2 showed a greater depth of carbonation compared to that presented by the specimens subjected to combined action. This may be related to changes in properties of the matrix which may lead to further refinement of the pores and related to the presence of the salt that can lead to partial filling of the pores and the increase in moisture content.",
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Malheiro, R, Camoes, A, Ferreira, M, Meira, G, Amorim, T & Reis, R 2015, Carbonation front progress in mortars containing fly ash considering the presence of chloride ions. in J Aguiar, A Camões, R Fangueiro, R Eires, S Cunha & M Kheradmand (eds), Sustainable Construction Materials. Key Engineering Materials, vol. 634, pp. 214-221. https://doi.org/10.4028/www.scientific.net/KEM.634.214

Carbonation front progress in mortars containing fly ash considering the presence of chloride ions. / Malheiro, R.; Camoes, A.; Ferreira, Miguel; Meira, G.; Amorim, T.; Reis, R.

Sustainable Construction Materials. ed. / José Aguiar; Aires Camões; Raul Fangueiro; Rute Eires; Sandra Cunha; Mohammad Kheradmand. 2015. p. 214-221 (Key Engineering Materials, Vol. 634).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

TY - GEN

T1 - Carbonation front progress in mortars containing fly ash considering the presence of chloride ions

AU - Malheiro, R.

AU - Camoes, A.

AU - Ferreira, Miguel

AU - Meira, G.

AU - Amorim, T.

AU - Reis, R.

PY - 2015

Y1 - 2015

N2 - The incorporation of fly ash (FA) in cementitious matrices have 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 partially consumed by the pozzolanic reactions, which facilitates the advancement of carbonation. Given that the combined action between carbonation and chloride penetration is a fact little known, we speculate about the behaviour of the matrix in this context. This study investigates the influence of the presence of chlorides on the carbonation in mortars with FA. Samples with 0% and 40% replacement of cement CEM I 42.5 R for FA were molded with water/binder 0.56 and 0.52 respectively. After 90 days of curing the specimens were subjected to cycles of immersion/drying for 56 days. Half of the samples was subjected to the following cycle: two days in a solution containing NaCl (concentration equal to 3.5 %); 12 days in the carbonation chamber (4% of CO2). The other half was: two days in water; 12 days in the carbonation chamber. Then, the development of carbonation was evaluated. The results indicate that the presence of chlorides influences the carbonation. The specimens submitted to the exclusive action of CO2 showed a greater depth of carbonation compared to that presented by the specimens subjected to combined action. This may be related to changes in properties of the matrix which may lead to further refinement of the pores and related to the presence of the salt that can lead to partial filling of the pores and the increase in moisture content.

AB - The incorporation of fly ash (FA) in cementitious matrices have 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 partially consumed by the pozzolanic reactions, which facilitates the advancement of carbonation. Given that the combined action between carbonation and chloride penetration is a fact little known, we speculate about the behaviour of the matrix in this context. This study investigates the influence of the presence of chlorides on the carbonation in mortars with FA. Samples with 0% and 40% replacement of cement CEM I 42.5 R for FA were molded with water/binder 0.56 and 0.52 respectively. After 90 days of curing the specimens were subjected to cycles of immersion/drying for 56 days. Half of the samples was subjected to the following cycle: two days in a solution containing NaCl (concentration equal to 3.5 %); 12 days in the carbonation chamber (4% of CO2). The other half was: two days in water; 12 days in the carbonation chamber. Then, the development of carbonation was evaluated. The results indicate that the presence of chlorides influences the carbonation. The specimens submitted to the exclusive action of CO2 showed a greater depth of carbonation compared to that presented by the specimens subjected to combined action. This may be related to changes in properties of the matrix which may lead to further refinement of the pores and related to the presence of the salt that can lead to partial filling of the pores and the increase in moisture content.

KW - carbonation

KW - chloride

KW - fly ash

KW - durability

KW - interaction

KW - diffusion

KW - permability

U2 - 10.4028/www.scientific.net/KEM.634.214

DO - 10.4028/www.scientific.net/KEM.634.214

M3 - Conference article in proceedings

SN - 978-3-03835-351-5

T3 - Key Engineering Materials

SP - 214

EP - 221

BT - Sustainable Construction Materials

A2 - Aguiar, José

A2 - Camões, Aires

A2 - Fangueiro, Raul

A2 - Eires, Rute

A2 - Cunha, Sandra

A2 - Kheradmand, Mohammad

ER -

Malheiro R, Camoes A, Ferreira M, Meira G, Amorim T, Reis R. Carbonation front progress in mortars containing fly ash considering the presence of chloride ions. In Aguiar J, Camões A, Fangueiro R, Eires R, Cunha S, Kheradmand M, editors, Sustainable Construction Materials. 2015. p. 214-221. (Key Engineering Materials, Vol. 634). https://doi.org/10.4028/www.scientific.net/KEM.634.214