Abstract
| Original language | English |
|---|---|
| Title of host publication | Sustainable Construction Materials |
| Editors | José Aguiar, Aires Camões, Raul Fangueiro, Rute Eires, Sandra Cunha, Mohammad Kheradmand |
| Pages | 214-221 |
| DOIs | |
| Publication status | Published - 2015 |
| MoE publication type | A4 Article in a conference publication |
Publication series
| Series | Key Engineering Materials |
|---|---|
| Volume | 634 |
| ISSN | 1013-9826 |
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Keywords
- carbonation
- chloride
- fly ash
- durability
- interaction
- diffusion
- permability
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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 proceeding › Conference article in proceedings › Scientific › peer-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 -