Mixture performance requirements

Layer thickness and compressive strength at an age of 28 days requirements must be in accordance with Table A10.6.

Table A10.6 HBMs minimum layer thickness and compressive strength
Layer	Road type					Footway/ footpath/ cycle track
Layer	0	1	2	3	4	Footway/ footpath/ cycle track
Combined Binder course & Sub-base	NP	NP	NP	NP	NP	150 mm C1.5/2
Base	NP	NP	NP	300 mm C1.5/2	200 mm C1.5/2	---
Base & sub-base	NP	450 mm C3/4	450 mm C3/4	450 mm C1.5/2	350 mm C1.5/2	---
Sub-base or below	150 mm C1.5/2	150 mm C1.5/2	150 mm C1.5/2	150 mm C1.5/2	150 mm C1.5/2	150 mm C1.5/2
Maximum strength class at 28 days	C9/12					C8/10
Notes: NP = Not permitted Minimum asphalt overlay thickness as per A3 to A7 HBMs are not permitted as CBGM base replacement