Bituminous mixtures

A2.8.2

The compacted thickness of all individual lifts of bituminous mixtures must be in accordance with Table A2.5 when checked in accordance with the destructive method in BS EN 12697-36.

Table A2.5 Compacted lift thickness (mm) – Bituminous mixtures
		Compacted lift thickness (mm)
Material type	PD 6691 reference	Minimum at any point	Nominal lift thickness	Maximum at any point
6 mm DSC	AC6 dense surf	15	20 – 30	40
10 mm CGSC	AC10 close surf	25	30 – 40	50
15/10 HRA	HRA 15/10 F surf	25	30	50
30/10 HRA	HRA 30/10 F surf	30	35	45
30/14 HRA	HRA 30/14 F surf HRA 30/14 C surf	35	40	50
35/14 HRA	HRA 35/14 F surf HRA 35/14 C surf	40	45 - 50	60
55/14 HRA	HRA 55/14 F surf	40	45	55
55/10 HRA	HRA 55/10 F surf	35	40	50
6 mm SMA	SMA 6 surf	15	20 - 40	45
10 mm SMA	SMA 10 surf	20	25 - 50	55
14 mm SMA	SMA 14 surf	30	35 - 50	55
10 mm PA	PA 10*	25*	30 – 35*	40*
20 mm PA	PA 20*	40*	45 – 60*	65*
50/14 HRA	HRA 50/14 F bin	30	35 - 65	85
50/20 HRA BC	HRA 50/20 bin	40	45 - 80	100
60/20 HRA BC	HRA 60/20 bin	40	45 - 80	100
14 mm SMA BC	SMA 14 bin	25	30 - 60	65
20 mm SMA BC	SMA 20 bin	40	50 - 100	110
14 mm DBC	-	35	40 - 70	80
20 mm DBC	AC20 dense bin	40	50 - 100	110
Notes: The binder course thickness must be adjusted accordingly to the thickness of the surface course to comply with the requirements in appendices A3 to A7. * The use of Porous Asphalt (PA) is limited in the UK except for specialist uses such as sustainable drainage systems. Where porous asphalt surfaces are encountered refer to S6.4.13 (BS EN 13108-7 contains specifications for this group of asphalts and guidance on the appropriate material should be obtained from the authority). ** 14 mm DBC is not currently included in PD 6691. It should be referenced as AC14 dense bin.