BRE BR386 PDF

INTRODUCTION

The work described in this report was undertaken by BRE under the "BRE Framework Programme" as part of the "Whole life costs" area of the DETR Technology and Performance Business Plan. This report is a scheduled output of the contract.

High alumina cement (HAC) concrete was used extensively in the UK from the 1950s to the early 1970s in the manufacture of pre-cast, pre-stressed concrete beams and some other building components. However, following a few cases of structural failure associated with loss of strength, HAC has not been recommended for use in structural concrete in the UK since the mid-1970s. Extensive research into the structural performance of HAC concrete construction led to the publication of detailed guidance and recommendations on designcheck procedures by the Building Regulations Division of the Department of the Environment (DoE) in July 1975⁽¹⁾. This guidance is still used today to assess the structural performance of the many tens of thousands of buildings in the UK containing such pre-cast HAC concrete beams. However, these buildings are now all over twenty years old and there has been great demand within the engineering community for methods and guidance for assessing their performance in service. HAC is also known as Calcium Aluminate cement (CAC).

The purpose of this project, which began in April 1998, is to provide data, guidance and advice on HAC concrete. It continues studies that were established under an earlier contract with DoE. From this earlier work, the key durability issues with respect to HAC concrete construction have been identified. This report provides a literature review focussing on these issues and describes the results of laboratory and field studies undertaken by BRE. The implications of the findings of this work in respect of the risk of deterioration of HAC concrete construction is then discussed. Recommendations for future work are also made.

The report is the source of the information presented in the BRE Information Paper "guidance on the durability of pre-cast HAC concrete in buildings".