Calcium nitrate effectively mitigates alkali–silica reaction by surface passivation of reactive aggregates
Fuente:
Wiley Open Access
Salvato in:
| Autori principali: | , , , , , , , |
|---|---|
| Natura: | Artículo Open Access |
| Pubblicazione: |
Wiley
2024
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1867019634222301184 |
|---|---|
| author | Rui Xiao Dale Prentice Marie Collin Magdalena Balonis Erika La Plante Mehrdad Torabzadegan Torben Gadt Gaurav Sant |
| author_facet | Rui Xiao Dale Prentice Marie Collin Magdalena Balonis Erika La Plante Mehrdad Torabzadegan Torben Gadt Gaurav Sant Rui Xiao Dale Prentice Marie Collin Magdalena Balonis Erika La Plante Mehrdad Torabzadegan Torben Gadt Gaurav Sant |
| collection | Wiley Open Access |
| contents | Calcium nitrate effectively mitigates alkali–silica reaction by surface passivation of reactive aggregates Rui Xiao Dale Prentice Marie Collin Magdalena Balonis Erika La Plante Mehrdad Torabzadegan Torben Gadt Gaurav Sant Journal of the American Ceramic Society Abstract Calcium nitrate (CN: Ca(NO 3 ) 2 ) has been shown to mitigate alkali–silica reaction (ASR) in concrete. Such ASR mitigation has been suggested to be on account of precipitate (i.e., barrier or passivation layer) formation‐induced dissolution inhibition of reactive/dissolving aggregate surfaces. Herein, we examine the ability of CN to mitigate ASR across two cements (Type I/II and Portland Limestone Cement), for aggregates of varying reactivity, and across different types and dosages of SCMs (supplementary cementitious materials, i.e., amorphous steel slag and Class C and Class F fly ashes). Based on expansion measurements carried out as per ASTM C1260/C1567, it is observed that CN, as a function of dosage, substantively mitigates ASR in mortar formulations across aggregate types. Careful microstructural examinations, dissolution studies, and thermodynamic calculations indicate that CN induces the formation of C–S–H, portlandite (Ca(OH) 2 ), and calcite (CaCO 3 ) precipitate mixtures, which form on aggregate surfaces at the expense of typical ASR gels. Such precipitates create a dissolution barrier and inhibit ASR in both SCM‐free and SCM‐containing formulations. The outcomes indicate that CN is an efficient and cost‐effective ASR mitigation additive (∼$250–$600 per tonne), particularly in a time of dwindling fly ash supplies and unaffordable lithium prices (>∼$12 000 per tonne). 10.1111/jace.20004 http://onlinelibrary.wiley.com/termsAndConditions#vor |
| doi_str_mv | 10.1111/jace.20004 |
| format | Artículo Open Access |
| id | wiley_oa_10_1111_jace_20004 |
| institution | Wiley Open Access |
| license_str_mv | http://onlinelibrary.wiley.com/termsAndConditions#vor |
| publishDate | 2024 |
| publisher | Wiley |
| record_format | wiley_oa |
| spellingShingle | Calcium nitrate effectively mitigates alkali–silica reaction by surface passivation of reactive aggregates Rui Xiao Dale Prentice Marie Collin Magdalena Balonis Erika La Plante Mehrdad Torabzadegan Torben Gadt Gaurav Sant Journal of the American Ceramic Society Calcium nitrate effectively mitigates alkali–silica reaction by surface passivation of reactive aggregates Rui Xiao Dale Prentice Marie Collin Magdalena Balonis Erika La Plante Mehrdad Torabzadegan Torben Gadt Gaurav Sant Journal of the American Ceramic Society Abstract Calcium nitrate (CN: Ca(NO 3 ) 2 ) has been shown to mitigate alkali–silica reaction (ASR) in concrete. Such ASR mitigation has been suggested to be on account of precipitate (i.e., barrier or passivation layer) formation‐induced dissolution inhibition of reactive/dissolving aggregate surfaces. Herein, we examine the ability of CN to mitigate ASR across two cements (Type I/II and Portland Limestone Cement), for aggregates of varying reactivity, and across different types and dosages of SCMs (supplementary cementitious materials, i.e., amorphous steel slag and Class C and Class F fly ashes). Based on expansion measurements carried out as per ASTM C1260/C1567, it is observed that CN, as a function of dosage, substantively mitigates ASR in mortar formulations across aggregate types. Careful microstructural examinations, dissolution studies, and thermodynamic calculations indicate that CN induces the formation of C–S–H, portlandite (Ca(OH) 2 ), and calcite (CaCO 3 ) precipitate mixtures, which form on aggregate surfaces at the expense of typical ASR gels. Such precipitates create a dissolution barrier and inhibit ASR in both SCM‐free and SCM‐containing formulations. The outcomes indicate that CN is an efficient and cost‐effective ASR mitigation additive (∼$250–$600 per tonne), particularly in a time of dwindling fly ash supplies and unaffordable lithium prices (>∼$12 000 per tonne). 10.1111/jace.20004 http://onlinelibrary.wiley.com/termsAndConditions#vor |
| title | Calcium nitrate effectively mitigates alkali–silica reaction by surface passivation of reactive aggregates |
| topic | Journal of the American Ceramic Society |
| url | https://ceramics.onlinelibrary.wiley.com/doi/10.1111/jace.20004 |