Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

AARtfully done


Your article on cement with higher than certified alkalis, leading to alkali aggregate reaction (AAR) risk in the South West, beautifully illustrates how complacency, 30 years after the UK's fi rst AAR at Charles Cross, has led to a recurrence of concerns.

Lafarge, having identified rogue data, seems to be taking a responsible approach. Its problems will be aggravated as cement industry pressure on the Hawkins' Committee reduced the safety margin for variability of cement alkali and content in concrete.

A ominal kg/m 3 alkali', actually gives up to 3.5kg/m 3 average in some concrete pours, with over 4kg/m 3 locally from normal variability and segregation.

Checking the actual risk of damage in structures from this high alkali cement must be based on rigorous IStructE techniques and comparisons with data from the investigation and appraisal of structures.

These evaluate the structural sensitivity, environment, expansive potential and consequences of failure to give an overall measure of the severity of potential consequences of AAR Jonathan GM Wood, Structural Studies & Design, Northbridge House, Chiddingfold, Surrey GU8 4UU.

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.