Concrete @ your Fingertips

Aureole in concrete

These appear as dark rings around tie-bolt holes. They are caused by localised loss of water at tie-bolt hole in formwork, causing localised changes in the water/cement ratio.

Effective sealing of formwork around tie-bolts reduces the risk of their occurrence.

Acknowledgement: Concrete Society

Concrete Bookshop - Members receive 40% discount on Concrete Society publications

Visual Concrete: Control of blemishes