Mastic Asphalt (Gussasphalt)
Mastic asphalt, per se, is a very rich mix of bitumen and limestone filler. It often also contains aggregate (sand, or crushed rock). Grade and type vary according to end use.
Mixed hot and very mobile in character, mastic asphalt is self-levelling and produces a totally impermeable surface.
This is why mastic asphalt is often used as the watertight membrane on bridge decks and dams, and for surfacing flat roofs and multi-storey car park decks. It can be supplied in readymade 25kg blocks which have to be melted in special mastic boilers prior to use. Certain grades can be manufactured in modern asphalt plants, such as Northstone's plant at its Croaghan Depot. Thinner, more fluid grades are spread using deck squeegees, stiffer grades by hand using wooden floats. The stiffest grades can be laid using a mechanical spreader.
Northstone has experience of manufacturing and installing mastic asphalt. Our Croaghan plant manufactured the material that was laid on the Foyle Bridge during strengthening and refurbishment work carried out in 2005. We also resurfaced the bridge.
Using specialist contractors, Northstone also renovated the Dungonnel Dam near Cargan in Co. Antrim. The contract consisted of the removal of the residue of the original spalled and eroded mastic by shot-blasting, and the resurfacing of the whole upstream face of the dam to 2m below normal water level.
[Note mastic asphalt is NOT the same as stone mastic asphalt (SMA). SMA is a road surfacing material consisting of a coarse aggregate skeleton filled with a fine "mastic" of binder and filler].
