EME2 on the M9 / A90 Spur
Project brief that included 27,300 tonnes of EME2
Client: Morrison Construction / Transport Scotland
Value: £6.20m
Duration: 12 months
Completion: September 2007
Project brief that included 27,300 tonnes of EME2
Tarmac were the specialist subcontractor awarded a £6.2m contract by Morrison Construction to undertake all surfacing works on the M9 / A90 Spur. Almost 200,000 tonnes of asphalt were laid over a 12 month period that included 27,300 tonnes of high strength, long life EME2 along heavily laden sections of the A90.
Generally, EME2 provided Transport Scotland with a 15% thinner overall construction thickness when compared to an HDM option. The use of EME2 reduces the number of layers of bituminous material laid, hence saving time and labour / plant costs, whilst providing greater resistance to deformation.
An active and leading involvement in trials of EME2
Developed in lieu of HMB 15, EME2 (Enrobé à Module) is the generic title for high strength, long life asphalt base and binder courses providing better workability, improved impermeability and greater resistance to cracking and deformation. This provides clients with pavements that do not deteriorate under prolonged heavy use.
Our knowledge of EME2 is unsurpassed in the UK, having been at the forefront of promoting it's use since 2001. We have played an active role in both the development and drafting of the material specification. This input has been undertaken both as part of ongoing QPA trials and in a private capacity, working with Nynas, our partner for bitumen supply.
This early and ongoing involvement means we have accrued considerable expertise in designing EME2 and have invested £250,000 in new test equipment installed at our UKAS accredited laboratory in Wolverhampton.
This new laboratory ensures that mix designs are fully designed in-house, quickly and under our own control. It also allows further review and analysis to be carried out into EME2 performance.
Mix design is a crucial matter for EME2 with each blend of aggregate and binder designed to meet exacting performance criteria. Tarmac has a sufficient number of approved EME2 compliant designs, covering 10, 14 and 20mm aggregate sizes and including limestones, gritstones and granites, to provide coverage for any site across the UK from Tarmac's own production units.
Site based trials to prove the material's properties
Following earlier trials undertaken in conjunction with TRL, Tarmac laid 250 tonnes of EME in the spring of 2004 as part of specialist surfacing subcontract on the A21 Lamberhurst Bypass in Kent. The EME was laid on a temporary diversion of the A21 (and therefore heavily trafficked) and then removed on completion of the new section of highway. We were the first company to use the current UK specification (TRL 636) under fully commercial conditions when, in June 2005, we supplied and laid 5,500 tonnes on the Bankhead to River Carron section of the M876, south of Stirling. The material was laid in lanes one and two of the northbound carriageway utilising 0/20mm and 0/10mm EME2 mixtures Shortly after the success of this trial Transport Scotland issued a letter that formally sanctioned the use of EME2 on trunk roads.
Use of locally sourced materials reduced transportation movements
Aggregate for the EME2 was supplied from Tarmac's Cruicks Quarry in Inverkeithing, Fife, with the 15/25 PEN bitumen binder supplied by Nynas from its refinery in Dundee. Tarmac's asphalt plant at Cruicks Quarry mixed and supplied all 25,000 tonnes.
Online upgrading of the A90 involved laying a lower and upper base, utilising a 0/20mm EME2 mixture, at depths of 140mm and 100mm respectively. The finished surface course was 10mm Masterflex with a 65psv.
Comment:
"Our strategy is now to use EME2 on trunk roads where appropriate"
Dougie Millar, Materials and Quality Assurance Advisor, Transport Scotland
"As a main contractor we benefit from a reduced maintenance risk"
Alan Smith, Project Manager, Morrison Construction
Download:
See more on Asphalt Surfacing
For further information on EME 2 please contact us.
Back to National Contracting Home
