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.
|Published (Last):||7 June 2014|
|PDF File Size:||18.2 Mb|
|ePub File Size:||13.32 Mb|
|Price:||Free* [*Free Regsitration Required]|
BS 1377 Part 3 Chemical Tests
Design guides for specific precast products. As in the previous cases, the concrete contained carbonate-bearing aggregates.
Provides guidance on the specification for concrete for installation in natural ground and in brownfield locations. Changes to sulfate classification The current and intended new limits for sulfate classes based on 2: Home Background to revision Key changes in SD1: Home Background to revision Key changes in SD1: Together with other findings, such as deficiencies in guidance for ground assessment, the new knowledge has prompted the current major revision of SD1.
The current and intended new limits for sulfate classes based on 2: In particular, it can come from bicarbonate dissolved in groundwater. Development of guidance on classification of sulfate-bearing ground for concrete.
BRE – Special Digest 1
Guidance on designing concretes to resist conventional sulfate attack was developed in a series of BRE Digests, ds1 most recent of which was Digest Sulfate and acid resistance of concrete in the ground, the first edition of which was published in BRE is a building science centre that generates new knowledge through research.
Design guides for common applications incorporating March amendment No longer current but cited in Building Regulations guidance.
It was apparent that the Digest needed to be revised to counter the risk of TSA occurrence and, in particular, to take into account the contribution made by carbonates. It has long been known in the UK that concretes made with Portland cements are brd to attack by sulfates in the ground.
Subsequently, inseveral cases of TSA were identified in the foundations to motorway bridges in Gloucestershire. Assessing the aggressive chemical environment incorporating March amendment No longer current but cited in Building Regulations nre. 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.
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.
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.
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. The Red document status indicator indicates that the 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 no longer being maintained by the editorial teams at NBS.
Document Status Indicators The Brd document status indicator indicates that the document is: In all three cases the concrete contained carbonate-bearing limestone aggregates. The new limits bring sulfate classification based on 2: Key outcomes in respect of the mechanism of TSA and concrete specification have been: They were further changed in BRE Digest The high profile of these cases ensured a co-ordinated national review, culminating in with bte report from a Thaumasite Expert Group TEG set up by Government.
It also gave recommendations for further research on occurrence of TSA and mitigating measures. In the majority of cases, the sulfate class limits based on soil extract tests sv1 both lower than sulfate class based on sulfate in groundwater and were also low when compared to the actual occurrence of TSA.
Design guides for specific precast products incorporating March amendment No longer current but cited in Building Regulations guidance. In the four years sincemuch of the research recommended by the TEG Report has been completed.
Assessing the aggressive chemical environment. The distinguishing features of this are that it. BRE helps its government and private sector clients meet the significant environmental, social and economic challenges they face in delivering homes, buildings and communities. 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.