Skip to main content

General requirements for ARMs and ATs (A9.2)

ARMs and ATs may only be used with the agreement of the authority obtained in accordance with the approval process described in A9.5.
The producer must maintain a Quality System that includes policy and procedures for production control. ARMs must be produced, handled, transported and used in accordance with the approved mix formulations and procedures proven by prior development and testing. ATs must be used in accordance with the procedures established by prior development and testing.
The authority must be notified of any alterations to the proven mix formulations, mix proportions, aggregate type, admixtures, procedures, etc. Confirmation of their suitability must be agreed, and further development and testing may be needed.
ARMs used within 450 mm of the road surface must be non-frost susceptible, but see S5.3.2 and S5.3.3.
Where the authority is aware of areas with drainage or groundwater problems, it should notify the undertaker. Following such notification, the undertaker must provide ARMs that are permeable to a degree not less than the surrounding ground at backfill and sub-base levels within trench reinstatement. A backfill layer of pea gravel of 100 mm minimum thickness and surrounded by a geotextile filter fabric (where appropriate) may be considered to offer equivalent drainage potential.
Surfacing materials must not be reinstated until the ARM has attained sufficient strength or has an immediate bearing index sufficient to allow adequate compaction of overlaying materials and sustain adequate traffic loading.
FSMRs can flow into any damaged drains or ducts nearby. Where required, plastic sheeting may be needed to provide protection during pouring.