Introduction

Through its technical consultancy work, BRE investigates the causes of a variety of materials durability problems. In some cases, these problems have needed further, more detailed laboratory-based studies and several DETR/DTI-funded research programmes have been established to satisfy this need and to provide relevant technical advice to the construction industry.

This report is the fifth of a series of 'technical intelligence' client reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. This report includes a number of case studies concerned with the deterioration of cement-based materials:

A Deterioration of concrete pipework associated with popcorn calcite deposition (PCD)

B Popcorn calcite deposition (PCD) in brickwork

C Cracking of motorway underbridge abutments and walls from delayed ettringite formation (DEF)

D Issues related to the possible presence of polychlorinated biphenyl (PCBs) in concrete and sealants

Case studies A, B and C are site are investigations. Case study D is somewhat different from others, being a literature review of case studies and other evidence. The results of a building survey carried out in Scandinavia are reviewed.

Annex 1 provides a description of the analytical techniques employed for the case studies and chemical formulae of the main minerals encountered. Annex 2 provides a list of the chemical and mineralogical laboratory techniques employed in the case studies.