The geotechnical properties of the pulverised coal ash produced at Moneypoint Power Station

Pulverised Fuel Ash (PFA) and Furnace Bottom Ash (FBA) are by-products from the combustion of coal at coal-burning power stations. This paper considers the geotechnical properties of the stockpiled PFA, FBA, and mixed... [ view full abstract ]

Pulverised Fuel Ash (PFA) and Furnace Bottom Ash (FBA) are by-products from the combustion of coal at coal-burning power stations. This paper considers the geotechnical properties of the stockpiled PFA, FBA, and mixed Pulverised Coal Ash (PCA) produced and stored at Moneypoint Power Station in County Clare, Ireland. Moneypoint is Ireland’s largest coal-burning power station and currently produces 162,000 tonnes of PFA and 18,000 tonnes of FBA per annum and houses a stockpile of 5,000,000 tonnes of mixed PCA. PFA and FBA are typically grey, weakly cemented, coarse-grained materials with particle size gradings similar to natural sands and gravels. PCAs have many uses as earthworks materials and engineering fills, although uptake is limited by a lack of knowledge of the properties of the materials, especially since the properties of a particular ash depend on the characteristics of the furnace and of the coal burned. The opportunity to carry out field and laboratory testing on the stockpiled PCA at Moneypoint arose during design work for the Moneypoint Wind Farm. The results of the field and laboratory testing carried out are presented in the paper, along with a brief discussion on the potential uses of the PCA from Moneypoint Power Station.