ASPHALT BITUMEN & PAVING SERVICES PERTH

Asphalt Car Parks

Carparking facilities in terms of the Australian Standard are referred to as either on street or off-street parking. Asphalt comes in all sizes from single bay to thousands of bays, and the bays can be accessed either at parallel, angle or right-angle direction.

In terms of asphalt there are two key elements to consider as follows:

• Method of construction; and
• Design of asphalt.

Traditionally developers, architects and design engineers have designed and specified construction of car parks such that the life of the pavement is not maximised. The unbound pavement construction follows regular construction process and then kerbing is installed including “tree diamonds” before the asphalt paving is laid. The consequence of this action is extensive areas of relatively poor compaction as asphalt paving equipment endeavours to negotiate the cluttered carpark area. Clients should consider constructing the asphalt paver laid base before the kerb to ensure appropriate compaction and resultant density results conducive with long life pavements.

In the case of parallel on street parking bays it is critical that the bays are marked to the correct length as specified in Australian Standard AS 2890.5–1993. The modern vehicle with its power steering has an ability to manoeuvre into the shortest of carparking bays which can result in premature ravelling of the pavement surface due to excessive tyre wear.

It is also imperative that the correct asphalt design is used to surface the carpark. Australian Asphalt Paving Association (AAPA) publication “Asphalt for Lightly Trafficked Streets” prescribes that only a dense graded or gap graded asphalt paver laid base be used for lightly trafficked streets including carparks.

Although Stone Mastic Asphalt (SMA) is a gap graded asphalt, it has a very high proportion of course aggregates. Consequently, it is not recommended for carparks due to its propensity to flush and/or ravel under the stress of turning movements.

Roads 2000 recommends that only dense graded asphalts are used in both on street and off-street carparks.

See our References below for more information:

1. Australian Standard AS 2890.5-1993 Parking Facilities, Part 5 On-Street Parking.
2. Australian Asphalt Paving Association Advisory Note 5, A Guide to Asphalt for Lightly Trafficked Streets.

Roads2000 - Notes #08 Carparks

Asphalt Mixes for Roundabouts

Roundabouts have become the most utilised form of traffic management in the urban environment. They are also subject to high levels of stress due to turning and braking movements.

There are a number of options for the paving of roundabouts however, the Australian Asphalt Paving Association (AAPA) recommends the following:

• Asphalt should be dense grade, preferred 14AC (75 Blow Marshall).
• Class 320 bitumen should be used as the binder, possibly modified for heavy traffic.
• Corrector layer depth should be appropriate to the stone size (5x).
• Traffic should not be allowed on the asphalt paving laid until sufficiently cool (not exceeding 40°C)

Please Note:

• The limits in brackets are not AAPA comments but are recognised as industry standards.
• Roads 2000 supports the recommendations from AAPA.
• Less stiff asphalts may be considered in low traffic local roundabouts.

If you require advice on our asphalt paver laid base or resurfacing services for roundabouts, Roads 2000 can provide advice to clients on the mix designs where required. Contact us today on (08) 9202 0800.

See our References below for more information:

1. IPWEA/AAPA Technical Specification, Tender Form and Schedule for Supply and Laying of Hot Asphalt Road Surfacing (Rev 3, April 2002)
2. AAPA Fundamentals of Bituminous Surfacing (2010)
3. AAPA Advisory Note 3 A Guide to Asphalt Mixes for Roundabouts (undated)

Roads2000 - Notes #05 Roundabouts