Leiths finished the second big volume works on Friday 14 June 2013, which was completed to the satisfaction of all involved with this prestigious contract.
The material used was a Gussaphalt mastic asphalt. This is a special mastic asphalt which relies on the properties of the bitumen mixed with crushed stone from Achilty Quarry and limestone fines from Leiths Fort William Quarry to provide the stiffness and durability required for a bridge running surface. This mastic asphalt is impermeable to air and water, which provides a longer service life for the mastic since it is the permeation of water and oxygen which causes the ageing process of asphalt pavements.
Aeschlimann developed the mastic asphalt for Kessock Bridge. It was produced at Leiths Plant in accordance with Aeschlimann specifications. Leiths supplied the material from the quarry at Achilty which is in Contin, about 16 miles North of the bridge. The Gussaphalt was transported in special delivery trucks which have the ability to mix and heat the material. The mix was laid by using a surface finishing machine travelling on steel rails which enables the best regularity to be achieved. Good smoothness provides better ride comfort and reduces bridge movement under load thus extending the life of the bridge. A 2/6mm chip was embedded in the surface course material to provide some surface texture.
Simon Russell, Group CEO, was keen to pass on his special thanks to the Team at Achilty, who pulled out all the stops in ensuring an uninterrupted supply of a difficult material.