The Building Research Establishment (BRE) has recently revised Special Digest 1 “Concrete in aggressive ground”. This new edition (SD1. Find the most up-to-date version of BRE – SD1 at Engineering Provides guidance on the specification for concrete for installation in natural ground and in brownfield locations. The procedures given for the ground.
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It is unfortunate that, through these changes, they gained an apparent precision that has imparted greater confidence in the derived classification than is warranted. Accordingly, in a new version of Digest was issued which drew attention to the risk of TSA in concretes containing internal calcium carbonate and promised further guidance based on on-going research.
Again there may be more recent versions of the document. The consequence of this adjustment will be to make the ground classification based on soil tests more conservative, eg some soils that were previously classified as DS-2 would now be considered as being DS In the four years sincemuch of the research recommended by the TEG Report has been completed.
Development of guidance on classification of sulfate-bearing ground for concrete. In particular, it can come from bicarbonate dissolved in groundwater. Design guides for common applications incorporating March amendment No longer current but cited in Building Regulations guidance.
Design guides for specific precast products. No field data would appear to have been available for correlation with sulfate classes based ssd1 sulfate levels in groundwater. Home Background to revision Key changes in SD1: These ball-park limits were converted in in BRE Digest to 2: Document Status Indicators The Green document status indicator indicates that the document is: The Amber document status indicator indicates that some caution is needed when using this document – it is either: Home Background to revision Key changes in SD1: The Trust uses the profits made by the BRE companies to fund research and education s1 advances knowledge of the built environment.
It was concluded that the concrete had suffered attack despite it satisfying the recommendations of the then-current version of Digest in respect of Sulfates Class 3 ground conditions. One of the key drivers for revision of BRE Digests dealing with concrete in aggressive ground since the s has been a growing recognition of the occurrence the thaumasite form of sulfate attack TSA in UK buildings and structures.
The high profile of these cases ensured a co-ordinated national review, culminating in with a report from a Thaumasite Expert Group TEG set up by Government.
BRE is a building science centre that xd1 new knowledge through research. Specifying concrete and additional protective measures incorporating March amendment No longer current but cited in Building Regulations guidance.
BS 1377 Part 3 Chemical Tests
Background to the revision One of the key drivers for revision of BRE Digests dealing with concrete in aggressive ground since the s has been a growing recognition of the occurrence the thaumasite form of sulfate attack TSA in UK buildings and structures.
In the early s, the thaumasite form of sulfate attack TSA became recognised as a bree mechanism affecting concrete in the UK. The Red document status indicator indicates that sd11 document is an old version The document has likely been withdrawn by the publisher, also the meta data presented here may be out of date as it is dd1 longer being maintained by the editorial teams at NBS. SD 1 Concrete in aggressive ground. The procedures given for the ground assessment and concrete specification cover the fairly common occurrences of sulfates, sulfides and acids, and the more rarely occurring aggressive carbon dioxide found in some ground and surface waters, which affects concrete foundations and sub-structures.
BRE – Special Digest 1
Assessing the aggressive chemical environment incorporating March amendment No longer current but cited in Building Regulations guidance. The current and intended new limits for sulfate classes based on 2: Changes to sulfate classification The current and intended new limits for sulfate classes based on 2: This document Newer versions Older versions.
It has long been known in the UK that concretes made with Portland cements are vulnerable to attack by sulfates in the ground. Key outcomes in respect of the mechanism of TSA and concrete specification have been:.
A review of the historical background to sulfate assessment has thrown light on how the current discrepancy came about. This is used to create products, tools and standards that drive positive change across the built environment.
Design guides for specific precast products incorporating March amendment No longer current but cited in Building Regulations guidance. They were further changed in BRE Digest It was apparent that ss1 Digest needed to be revised to counter the risk of TSA occurrence and, in particular, to gre into account the contribution made by carbonates.
BRE helps its government and private wd1 clients meet the significant environmental, social and economic challenges they face in delivering homes, buildings and communities. This was published in as Special Digest 1: The distinguishing features of this are that it.
The new limits bring sulfate classification based on 2: Together with other findings, such as deficiencies in guidance for ground assessment, the new knowledge has prompted the current major revision of SD1. Assessing the aggressive chemical environment. As in the previous cases, the concrete contained carbonate-bearing aggregates. In all three cases the concrete contained carbonate-bearing limestone aggregates.
SD 1 Concrete in aggressive ground. 3rd edition, BRE – Publication Index | NBS
It also gave recommendations for further research on occurrence of TSA and mitigating measures. Free to use BIM project management tool provides step-by-step help to define, manage and validate responsibility for information development and delivery at each stage of the asset life cycle in level 2 BIM projects.
Provides guidance on the specification for concrete for installation in natural ground and in brownfield locations. In sc1 majority of cases, the sulfate class limits based on soil extract tests were both lower than sulfate class based sc1 sulfate in groundwater and were also low when compared to the actual occurrence of TSA.
Design guides for common applications. Guidance on designing concretes to resist brf sulfate attack was developed in a series of BRE Digests, the most recent of which was Digest Sulfate and acid resistance of concrete in the ground, the first edition of which was published in Gives procedures for specification of concrete and applies to both buildings and civil engineering construction.
Key brf in respect of the mechanism of TSA and concrete specification have been: Want access to British Standards? The change stems from findings of numerous research ground investigations carried out by BRE and others on Sc1 concrete trial sites and locations where TSA has occurred.
Subsequently, inseveral cases of TSA were identified in the foundations to motorway bridges in Gloucestershire.