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
Appendix Z – Guidance Notes on the Preparation of Job
Specifications
Z.1 LIMITATION ON THE USE OF HOT
ROLLED ASPHALT
Z.1.1 Hot Rolled Asphalt may be used for
surface courses in relation to aircraft tyre
pressures and frequency of trafficking in
accordance with Table Z.1.
Z.1.2 The frequency of trafficking is as defined
in “A guide to airfield pavement design and
evaluation” (Property Services Agency 1989) but
with the overriding requirements as follows:
Low frequency Maximum of 50 movements
per week by aircraft in the
critical tyre pressure range;
and
Medium frequency Maximum of 500 movements
per week by aircraft in the
critical tyre pressure range.
High frequency Greater than 500 movements
per week by aircraft in the
critical tyre pressure range.
Z.1.3 Notwithstanding Table Z.1, recipe Hot
Rolled Asphalt mixtures may be specified for hand
laying small areas.
Z.1.4 The Specification for Hot Rolled Asphalt is
for surface courses only.
Z.1.5 Prior to using this Specification for Hot
Rolled Asphalt for runway resurfacing work, the
Project manager shall obtain advice from
Professional and Technical Services, DE
regarding such matters as grooving and surface
texture requirements or the application of coarse
textured slurry seal (normally the least favoured
option).
Z.2 LIMITATION ON THE USE OF
ASPHALT CONCRETE (MACADAM)
Z.2.1 Asphalt Concrete (Macadam) may be
used for surface courses and binder courses in
relation to aircraft tyre pressures and frequency of
trafficking in accordance with Table Z.2.
(NOTE. Close graded surface course Asphalt Concrete
(Macadam) may have a low texture depth, and hence
poor skid resistance, when new. It is therefore not
normally recommended for runways. Consideration
should be given to applying a coarse slurry seal when
new if surfacing a runway to provide some surface
texture, and within 5 years in other situations to seal the
surface and arrest binder hardening.)
TABLE Z.1 TRAFFICKING LIMITATIONS ON THE USE OF HOT ROLLED ASPHALT
Tyre Pressure Frequency of Trafficking
Low Medium High
MPa (psi) Recipe Design Recipe Design Recipe Design
mixture mixture mixture mixture mixture mixture
up to 0.7 (100)
0.7 to 1.4 (100 to 200)
More than 1.4 (200)
Yes
No
No
Yes
Yes
Yes
No (Yes)
50 July 2010
No
No
Yes
Yes
Yes †
No
No
No
Yes
Yes
Yes †
Yes Hot Rolled Asphalt is permitted.
No Hot Rolled Asphalt is not permitted.
(Yes) Hot Rolled Asphalt is permitted in the cooler, northern regions of the UK only, subject to prior advice
being sought from Professional and Technical Services, DE.
Yes † Hot Rolled Asphalt is permitted for small works only, subject to prior advice being sought from
Professional and Technical Services, DE.