Along with heavy traffic, extreme cold temperatures are the biggest risk to damaging external concrete surfaces, particularly freeze-thaw cycles experienced during the winter. Additionally, de-icing salts used on public roads and concrete greatly increases the damaging effects of freezing.
Frost damage can cause extensive scaling and spalling, which results in the top layer of concrete coming off. This can be prevented by ensuring concrete is adequately designed, produced, placed, finished and cured.
When planning external concrete slabs please consider the following:
• Engage with a third party quality accredited supplier and select the correct mix for external paving; PAV 1 (C35n air entrained or 50N), or PAV 2 (40n air entrained or 50N).
• Choose an experienced and competent concrete installer and discuss the concrete mix and installation techniques.
• Ensure slump/workability of the concrete is agreed between supplier and installer.
• Discuss slab depth and joint placement with concrete installer and if in doubt consult an engineer.
• Ensure plan is in place for good curing for immediately after concrete being placed.
• Use fibres in concrete to reduce risk of cracking and increase surface strength.
• Install concrete in very cold or very hot temperatures, rainy or windy days.
• Add additional water to concrete on-site to increase the slump – this will weaken concrete and can result to quality issues with the concrete.
• Traffic concrete paving too soon – leave 28 days until it reaches full strength.
• Use air entrained mixes for power- floated finishes, consult quality accredited supplier for more information.
If you need assistance with concrete mixes or to help recommend a suitable competent concrete layer consultant with a third party quality-accredited supplier.
The MPANI is the principal trade association for the quarrying and quarry products industry in Northern Ireland affiliated to the Minerals Products Association (MPA) in the UK.
For further information call: +44 (0)28 9082 4078 or email [email protected]
QSRMC registered companies:
• LD Aggregates, Cookstown
• B McCaffery & Sons Ltd, Enniskillen
• Breedon/Whitemountain, All Sites
• Northstone NI Ltd, All Sites
• Tracey Concrete, Enniskillen
• Quinn Building Products, Enniskillen
• Norman Emerson Group, Craigavon
• F P McCann, All Sites
• Clady Quarries, Newry, Armagh
• Creagh Concrete, All Sites
• Gregory Donnelly S & G, Strabane
• Carryduff Building Supplies, Carryduff
BSI registered companies:
• Alpha Quarry Products Ltd, Co Down
• RTU Ltd, Newtownabbey
• CES Quarry Products Ltd, Newtownards
• Carryduff Concrete, Lisburn
• Neil Mullin & Sons Limited, Omagh
• McGarrity Bros, Omagh
• CES Quarry Products Ltd, Saintfield
• Loughran Rock Quarries Ltd, Carrickmore
• Macrete Ireland Limited, Toomebridge
• Robinson Concrete Ltd, Claudy
• Robinson Concrete Ltd, Ballymoney
• Stoneyford Building Supplies, Lisburn
• Loughran Rock Industries, Armagh
• Joseph Barrett & Sons Ltd, Dungannon
• W & J Chambers Ltd, Coleraine
• W J Chambers Ltd, Londonderry