Hot Rolled Asphalt and Asphalt Concrete (Macadam) - Ministry of ...

Specification 12 Hot Rolled Asphalt and Macadam Appendix Z – Guidance Notes on the Preparation
for Airfields of Job Specifications
TABLE Z.3 STABILITY REQUIREMENTS FOR
HOT ROLLED ASPHALT
Tyre Pressure Stability Category
Frequency of Trafficking
MPa (psi) Low Medium High
Up to 0.7 (100) Smin5,0 Smin5,0 Smin7,5
(Smin5,0)
0.7 to 1.4 (100–200) Smin5,0 Smin7,5
(Smin5,0)
Smin10
More than 1.4 (200) Smin7,5 Smin10 ‡ Smin10 ‡
( ) Bracketed Categories apply in the cooler,
northern regions of the UK only, subject to
prior advice being sought from Professional
and Technical Services, DE.
‡ Hot Rolled Asphalt or Asphalt Concrete
(Macadam) should be permitted for small
works only subject to advice being sought from
Professional and Technical Services, DE.
Z.8 BITUMEN GRADES FOR USE WITH
ASPHALT CONCRETE (MACADAM)
Z.8.1 The grade of bitumen for surface course
and binder course Asphalt Concrete (Macadam)
may be selected from the Table Z.4.
Z.8.2 In cooler, northern regions of the UK, the
use of 160/220 paving grade bitumen allows for
greater longevity provided adequate structural
performance can be achieved. Where 40 mm
thick surface course is specified, the use of
160/220 paving grade bitumen also maximises the
compaction time.
TABLE Z.4 GRADE OF BITUMEN
Z.8.3 The frequency of trafficking is as defined
in sub-Clause Z.1.2.
Z.9 WETTING AGENTS
It is recommended that the option to use Stearine
Amine or other approved wetting agent is
restricted to small works only.
Z.10 PAVING MACHINES
INCORPORATING EQUIPMENT TO
APPLY TACK OR BOND COAT
The Project Manager should seek guidance from
Professional and Technical Services, DE. In the
absence of more definitive information, approval
would need to be subject to a laying trial and
laboratory tests to demonstrate good adhesion,
that the tack or bond coat had broken and that
moisture had not been trapped.
Z.11 TEMPORARY RAMPS
Z.11.1 Phased working to allow aircraft
operations to continue, either throughout or at
intervals during the construction period (e.g. night
working and daytime flying) may necessitate the
provision of temporary ramps. Guidance is
provided at Appendix 3A of CAP 168, Licensing of
Aerodromes (Civil Aviation Authority).
Clause 7.23 may need to be modified or
augmented for specific job specifications and
must be subject to prior agreement with the
Aerodrome Authority/Station staff.
Tyre Pressure Frequency of Trafficking
Low Medium High
MPa (psi) Binder Surface Binder Surface Binder Surface
course course course course course course
up to 0.7 (100) 100/150 100/150
(160/220)
100/150 100/150
(160/220)
100/150 100/150
0.7 to 1.4 (100 – 200) 40/60 ‡ No 40/60 ‡ No 40/60 † No
More than 1.4 (200) 40/60 † No No No No No
( ) Bracketed values apply in the cooler, northern regions of the UK only, subject to prior advice being sought
from Professional and Technical Services, DE.
‡ For use in DBM 50 or, with increased filler content, in HDM.
† For use only with increased filler content in HDM.
52 July 2010