Exposed Concrete
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The durability of buildings with exposed concrete surfaces

Association for Structural Engineers of London Boroughs

David Rumsey - Chairman
BRETS
24 Uxbridge Road
London W5 2BP
Acting as agent for the London Borough of Ealing.
Preface
ASLEB, formerly known as SEMSELB until April 1998 was established in the early 1970's to provide a forum for structural engineers of London Boroughs to address and resolve problems common to many local authorities. The initial problem which drew local authority engineers together was the assessment of high rise precast concrete buildings following the collapse of Ronan Point in 1968.
At their regular meetings ASELB members have discussed the risk of injury to occupants and passers-by where concrete may spall and fall from a building. It is ASELB's view that all public buildings with exposed concrete surfaces should be inspected and maintained on a regular basis. This report is intended to be used with other documents published by the Building Research Establishment in order to ensure that buildings are safe for occupants and passers-by.


1. Introduction
i) During their service lives all buildings should be safe for occupants and passers-by who may be at risk from spalling concrete. Periodic inspections and maintenance will be necessary to achieve a safe environment.
2. Durability Appraisal
i) The regular inspection of public buildings should establish the current condition of the exposed concrete surfaces and provide answers to the following questions:
a) Is there now or likely to be during its service life a hazard from falling debris?
b) What interim safety precautions are needed before carrying out appropriate remedial measures? Interim safety precautions may be necessary to protect occupants and passers-by from spalling concrete.
3. Recommendations
i) All public buildings with exposed concrete surfaces should be subject to regular inspections for durability, the inspection frequency shall be at intervals of 1, 2 and 5 years or other period as deemed appropriate by a structural engineer.
ii) Interim safety precautions should be undertaken to protect site users where there is evidence of spalling concrete.
iii) Repairs should be undertaken in accordance with the recommendations of the inspection report.
4. Acknowledgements
i) Building Research Establishment.
5. References
i) The structural adequacy and durability of large panel system dwellings published by the BRE.
ii) Repair and Maintenance of Reinforced Concrete published by the BRE.