Alkali thresholds in concrete; the balanced alkali approach in ASR mitigation

Boyd-Weetman, B; Thomas, P; Sirivivatnanon, V; Nairn, J

Alkali thresholds in concrete; the balanced alkali approach in ASR mitigation

Boyd-Weetman, B Thomas, P

Sirivivatnanon, V Nairn, J

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Publisher:: LABORATÓRIO NACIONAL DE ENGENHARIA CIVIL, I. P.
Publication Type:: Conference Proceeding
Citation:: Proceedings of the 16th International Conference on Alkali-Aggregate Reaction in Concrete, 2021, 1, pp. 611-616
Issue Date:: 2021-01-01

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Field	Value	Language
dc.contributor.author	Boyd-Weetman, B
dc.contributor.author	Thomas, P https://orcid.org/0000-0001-6962-2121
dc.contributor.author	Sirivivatnanon, V
dc.contributor.author	Nairn, J
dc.contributor.editor	Lopes Batista, A
dc.contributor.editor	Santos Silva, A
dc.contributor.editor	Fernandes, I
dc.contributor.editor	Oliveira Santos, L
dc.contributor.editor	Custódio, J
dc.contributor.editor	Serra, C
dc.date	2022-05-31
dc.date.accessioned	2021-05-27T07:49:57Z
dc.date.available	2021-05-27T07:49:57Z
dc.date.issued	2021-01-01
dc.identifier.citation	Proceedings of the 16th International Conference on Alkali-Aggregate Reaction in Concrete, 2021, 1, pp. 611-616
dc.identifier.isbn	9789724923154
dc.identifier.uri	http://hdl.handle.net/10453/149276
dc.description.abstract	The Alkali Silica Reaction (ASR) is a deleterious reaction in concrete that poses significant durability concern worldwide. As a preventative measure, total alkali content of general purpose Portland cements can be limited. In Australia, like in other countries, general purpose cement is limited with a conservative alkali content of 0.6%, this may be unnecessary, as low risk non-reactive aggregates and SCM blends are effective in reducing ASR prevalence. Indeed there is a growing argument to transition to risk assessed methods in choosing cement alkali levels. ASTM in the USA has employed a prescriptive approach to selecting preventative measures that incorporates a variety of cement alkali contents without compromising on safety. Similar balanced alkali approaches such as those recommended in Europe, Canada and New Zealand may be applicable in Australia. Raising alkali limits to a level greater than 0.6% in cement used in conjunction with alternative mitigation techniques would reduce the economic and environmental impact associated with alkali removal during cement production. This literature review discusses the Australian approach to alkali limits in contrast to the methods used around the world and explores the continuing research into alkali’s mechanistic contribution to ASR.
dc.language	en
dc.publisher	LABORATÓRIO NACIONAL DE ENGENHARIA CIVIL, I. P.
dc.relation	http://purl.org/au-research/grants/arc/IH150100006
dc.relation.ispartof	Proceedings of the 16th International Conference on Alkali-Aggregate Reaction in Concrete
dc.relation.ispartof	16th International Conference on Alkali-Aggregate Reaction in Concrete
dc.rights	info:eu-repo/semantics/closedAccess
dc.title	Alkali thresholds in concrete; the balanced alkali approach in ASR mitigation
dc.type	Conference Proceeding
utslib.citation.volume	1
utslib.location.activity	Lisbon
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Strength - CBI - Centre for Built Infrastructure
pubs.organisational-group	/University of Technology Sydney/Faculty of Science/School of Mathematical and Physical Sciences
utslib.copyright.status	closed_access	*
pubs.consider-herdc	false
dc.date.updated	2021-05-27T07:49:56Z
pubs.finish-date	2022-06-02
pubs.place-of-publication	Lisbon
pubs.publication-status	Published
pubs.start-date	2022-05-31
pubs.volume	1
dc.location	Lisbon

Abstract:

The Alkali Silica Reaction (ASR) is a deleterious reaction in concrete that poses significant durability concern worldwide. As a preventative measure, total alkali content of general purpose Portland cements can be limited. In Australia, like in other countries, general purpose cement is limited with a conservative alkali content of 0.6%, this may be unnecessary, as low risk non-reactive aggregates and SCM blends are effective in reducing ASR prevalence. Indeed there is a growing argument to transition to risk assessed methods in choosing cement alkali levels. ASTM in the USA has employed a prescriptive approach to selecting preventative measures that incorporates a variety of cement alkali contents without compromising on safety. Similar balanced alkali approaches such as those recommended in Europe, Canada and New Zealand may be applicable in Australia. Raising alkali limits to a level greater than 0.6% in cement used in conjunction with alternative mitigation techniques would reduce the economic and environmental impact associated with alkali removal during cement production. This literature review discusses the Australian approach to alkali limits in contrast to the methods used around the world and explores the continuing research into alkali’s mechanistic contribution to ASR.

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http://hdl.handle.net/10453/149276