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Resin Bound Knowledge Base

Resin Bound Knowledge Base

Information - PEN Value

Asphalt/Bitumen (tarmacadam) surfaces are available in a variety of grades which amongst other test results are defined using a PEN (penetration) value. The PEN value is used to indicate the hardness of a bitumen surface with lower penetration values indicating a harder surface and higher values indicating a softer surface.

The optimum tarmacadam base-course PEN value for both resin bound and resin bonded surfacing is 70 to 100.

Resin bound: BS EN 13108-5
Bitumen 70 to 100 PEN – 20mm Open Graded

Resin bonded: BS EN 13108-5
Bitumen 70 to 100 PEN – 20mm Dense (Close) Graded

Penetration Value Test

If an existing surface is asphalt/tarmacadam and it shows any indications of movement/sinking, its PEN value is likely to exceed 100 and it should only be overlaid with a resin bonded system. If an existing asphalt/tarmacadam surface is over two years old and shows no indications of movement or water puddling then it may be suitable for a resin bound system.