CATASTROPHIC FAILURE of sub-standard rebar rolled from worn-out railway lines is a real risk for the UK construction industry, according to the UK Certification Body for Reinforcing Steels (CARES).
Reinforcement supplied by a small fabricator in north west England in sizes ranging from 8mm to 12mm is the main focus of suspicion after a sample badly failed a CARES test last month. CARES warned the steel is so poor that any localised heating during fabrication or handling could cause 'unexpected and catastrophic failure'.
CARES withdrew the quality assurance certificate from Preston-based A&M Reinforcement this week - the first such withdrawal in more than 15 years - for 'purchasing and supplying reinforcing steel not produced under a CARES Certificate of Approval.'
CARES executive director Ben Bowsher said that one of his assessors had carried out an unannounced inspection of the fabricator last month, and taken away a sample 10mm bar for analysis as, he said, 'the material's mill marks were untraceable.'
It is a fundamental requirement of the CARES scheme that all bars processed by fabricators come from CARES-approved sources. But subsequent lab tests revealed the suspect steel's chemical analysis to be 'way out', with mechanical properties 'highly variable', poor surface finish and gross surface defects.
'If this steel is handled incorrectly there is a real risk of structural failure,' Bowsher told NCE this week. 'And it is highly likely to be more than just the 10mm bar - 8mm and 12mm bars are also under suspicion.'
A&M has so far failed to disclose to CARES the non-approved source. Bowsher acknowledged there was a risk that other small fabricators had also obtained steel from this source. 'Customers should check the mill mark on any steel they are worried about,' Bowsher said (see picture). He added: 'I have my suspicions about the source and will be looking into it.
A spokesman for A&M said on Tuesday: 'This is a regrettable situation. We are still operating quality systems and constantly monitoring the situation.'