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Conditioned Fly Ash (PFA)

ScotAsh supplies two types of conditioned fly ash, or Pulverised Fuel Ash (PFA):

  • Conditioned fly ash, taken direct from Longannet Power Station and conditioned with water prior to delivery
  • Lagoon fly ash, which has been slurried at Longannet and Cockenzie Power Stations and pumped to lagoons. This material is excavated from the lagoons and allowed to stabilise to reduce its water content. If desired, it can also be screened prior to despatch.

Conditioned fly ash can be used as a general or structural fill material, for highway construction, or for capping. It can also be used as an addition in concrete, as an aggregate/filler in cementitious grouts, or bituminous road materials and in cement manufacture.

Conditioned fly ash is low density so can be used as a fill material over weak ground. When used in grout it gives good yields. There is very little consolidation after placing and the material offers immediate strength from the high value of apparent cohesion an a high angle of shearing resistance, while the continuing reaction between PFA and free lime means that it offers strength gains with time.

Conditioned ash is self-supporting, minimising the need for shoring. It has low permeability, assisting water run-off and it is a stable material chemically and physically. The spherical shape of the ash particles provides the additional benefits of a reduced water to solids ration, reduced bleeding and good flow properties.

Download our Conditioned PFA product information leaflet or the Health & Safety information leaflet