Square columns survive in concrete supports (9)

I believe the answer is:

pilasters

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'square columns' is the definition.
'pilasters' can be an answer for 'columns' (pilaster is a kind of column). I am unsure of the 'square' bit.

'survive in concrete supports' is the wordplay.
'survive' becomes 'last' (synonyms).
'in' is an insertion indicator.
'concrete supports' becomes 'piers' (pier is a kind of support. I am not sure about the 'concrete' bit.).
'last' inserted inside 'piers' is 'PILASTERS'.

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I've seen this clue in The Irish News.

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